BAW Code of Practice Use of Standard Construction Methods For

BAW Code of Practice

Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways (MAR)

Issue 2008

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Karlsruhe · December 2008 · ISSN 2192-9807 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

„MAR“ Working group

(April 2006 – December 2008)

Members:

BARTNIK, Wolfgang Dipl.-Ing., Wasserstraßen-Neubauamt Datteln

CONRADI, Stefan Dipl.-Ing., Wasser- und Schifffahrtsdirektion Ost, Magdeburg

FISCHER, Uwe Dipl.-Ing., Bundesministerium für Verkehr, Bau, und Stadtentwicklung, Bonn

FLEISCHER, Petra Dipl.-Ing., Bundesanstalt für Wasserbau, Karlsruhe

HEIBAUM, Michael Dr.-Ing., Bundesanstalt für Wasserbau, Karlsruhe

HOLFELDER, Tilman Dr.-Ing., Bundesanstalt für Wasserbau, Karlsruhe

KAYSER, Jan Dr.-Ing., Bundesanstalt für Wasserbau, Karlsruhe (Leiter der AG)

LIEBENSTEIN, Hubert Dipl.-Ing., Bundesanstalt für Gewässerkunde, Koblenz

NULLE, Undine Dipl.-Ing., Wasser- und Schifffahrtsamt Berlin

OSTERTHUN, Manuela Dr.-Ing., Wasser- und Schifffahrtsdirektion Mitte, Hannover

POHL, Martin Dr.-Ing., Bundesanstalt für Wasserbau, Hamburg

SÖHNGEN, Bernhard Prof. Dr.-Ing., Bundesanstalt für Wasserbau, Karlsruhe

SOYEAUX, Renald Dr.-Ing., Bundesanstalt für Wasserbau, Karlsruhe

STEIN, Jürgen Dr.-Ing., Bundesanstalt für Wasserbau, Karlsruhe

THYSSEN, Heinz-Jakob Dipl.-Ing., Wasser- und Schifffahrtsdirektion West, Münster

BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

II BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

Table of Contents Page

1 Preliminary Remarks 1

2 Terms and Definitions 2

3 Boundary Conditions for Standard Construction Methods 4 3.1 General 4 3.2 Types of vessel and hydraulic loads 5 3.3 Waterway cross-sections 7 3.4 Ground conditions 8

4 Revetment Components 10 4.1 Armourstones 10 4.2 Grout 11 4.3 Filter layers 11 4.4 Separation layers 11 4.5 Impervious lining systems 11 4.5.1 General 11 4.5.2 Flexible lining systems 12 4.5.3 Inflexible lining systems 12

5 Standard Methods of Construction 12 5.1 General 12 5.2 Armour layers 14 5.2.1 Permeable armour layers comprising riprap 14 5.2.2 Permeable armour layers comprising partially grouted armourstones 16 5.2.3 Impermeable armour layers comprising fully grouted armourstones 17 5.3 Toe protection 18 5.4 Flexible linings 20 5.5 Freeboard height 20 5.6 Selection of a standard method of construction 20 5.6.1 General 20 5.6.2 Requirement for an impervious lining 21 5.6.3 Soil classification 22 5.6.4 Requirement for a filter or a separation layer 22 5.6.5 Selection of an armour layer 23

6 Other Methods of Construction 23 6.1 General 23 6.2 Revetments in combined rectangular-trapezoidal (KRT) profiles 24 6.3 Impermeable erosion-resistant pavements 24

I BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

7 Vegetation Cover in Standard Methods of Construction 25 7.1 General 25 7.2 Permeable armour layers comprising riprap or partially grouted armourstones as described in sections 5.2.1 and 5.2.2 respectively 26 7.3 Impermeable armour layers comprising fully grouted armourstones as described in section 5.2.3 27 7.4 Guidance on vegetation cover on flexible linings 27

8 Guidance on Invitations to Tender, Execution of the Works, Quality Control and Maintenance 27 8.1 General 27 8.2 Invitations to tender 28 8.2.1 General 28 8.2.2 Armour layer 29 8.2.3 Underlayers 30 8.2.4 Minimum requirements for secondary tenders 30 8.3 Execution of the works 31 8.4 Quality assurance 32 8.4.1 General 32 8.4.2 Depth measurements for quality assurance 33 8.5 As-built documents 33 8.6 Guidance on maintenance 34

9 Literature 35

List of Tables

Table 3.2-1: Dimensions of ship types 5

Table 3.3-1: Geometry of the standard canal profiles N.B: Only the first bank is considered for the revetment design. 8

Table 3.4-1: Characteristic soil parameters for soil types B1 to B5 9

Table 4.1-1: 50 %-values for the standard size classes for riprap armour layers 11

Table 5.1-1: Void ratio of armourstone armour layers as a function of the method of installation (based on depth measurements taken at the highest points of the armourstones) 13

Table 5.2.1-1: Stone diameters, stone weights and size classes required for standard profiles approved for all types of inland waterway vessels (ES, GMS, SV, üGMS) for a range of densities (2300 – 3600 kg/m3) 15

Table 5.2.1-2: Recommended armour layer thicknesses (riprap) for slope and bottom revetments, taking account of the soils specified in 3.4 16

Table 8.2.1-1: Documentation to be provided on submission of a tender 29

II BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

List of Figures

Figure 3.2-1: Example of the most unfavourable position of a large self-propelled barge or push-tow unit at full draught in a T-profile 7

Figure 4.1-1: Definition of the design values G50, shown here for class LMB5/40 10

Figure 5.2.1-1: Diagram of the cross-section of a permeable armour layer of riprap 14

Figure 5.2.2-1: Diagram of the cross-section of a permeable armour layer comprising partially grouted armourstones 17

Figure 5.2.3-1: Diagram of the cross-section of an impermeable armour layer comprising fully grouted armourstones 18

Figure 5.3-1: Design of the toe protection 19

Figure 5.6-1: Criteria for the selection of an impermeable or permeable revetment 22

III BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

List of Annexes

Annex 3.1: Principles of hydraulic design in accordance with /GBB/ 38

Annex 3.2.1: Hydraulic loads at 97 % vkrit for standard T-profiles 40

Annex 3.2.2: Hydraulic loads at 97 % vkrit for standard RT-profiles 41

Annex 4.1-1: Guidance on how to determine the mean stone size, D50, or

the mean stone weight, G50 42

Annex 4.1-2: Cumulative curves for armourstones - classes LMB10/60, LMB5/40, CP90/250 43

Annex 5.2.1-1: Permeable armour layers comprising riprap – Recommended

thicknesses, dD, of armour layers for slope and bottom protection systems 44

Annex 5.2.1-2: Permeable armour layers comprising riprap - Documentation of the armour layer

thickness, dD, calculated for slopes (with a geotextile) 46

Annex 5.2.1-3: Permeable armour layers comprising riprap – Calculated minimum thicknesses 47

Annex 5.2.2-1: Permeable armour layers comprising partially grouted armourstones -

Recommended thicknesses, dD, of armour layers for slope and bottom protection systems (with a geotextile) 48

Annex 5.2.2-2: Permeable armour layers comprising partially grouted armourstones -

Documentation of the calculated armour layer thickness, dD, for slopes (with a geotextile) 49

Annex 5.2.3: Impermeable armour layers comprising fully grouted armourstones placed on

a geotextile – Required armour layer thickness, dD, against buoyancy 50

Annex 5.6.2-1: Permeable armour layers comprising riprap placed on a geotextile, with an

impermeable lining – Required armour layer thickness, dD, against buoyancy 51

Annex 5.6.2-2: Permeable armour layers comprising partially grouted armourstones placed on

a geotextile, with an impermeable lining – Required armour layer thickness, dD, against buoyancy 52

IV BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

1 Preliminary Remarks

The following Code of Practice deals with standard methods of constructing bank and bottom protection systems for inland waterways which may be used under defined boundary conditions without the need for verification by calculation.

The first edition of the Code was published in 1993. Considerably more is now known about how to exe- cute revetments, the actions on such structures and their stability. In addition, the relevant rules and standards have either been revised or rewritten. A thorough revision of the Code was therefore necessary and the revised version is now available as the present 2008 edition.

The standard methods of construction are based on experience in the construction and maintenance of revetments and on engineering design rules. The latter are to be found in the Principles for the Design of Bank and Bottom Protection for Inland Waterways /GBB/ which was also published by the Federal Wa- terways Engineering and Research Institute.

The standard construction methods have been drawn up both with present-day vessels and future shipping in mind, taking account of the increase in the number of large Rhine barges (self-propelled barges).

The principal geometries considered are the trapezoidal profile (T-profile) and the rectangular-trapezoidal profile (RT-profile) for Class Vb waterways in accordance with the Directives for the Standard Cross- Sections of Canals for Inland Shipping /RiReS/, with a blockage ratio, n, greater than 5.3. Application of the standard methods of constructing revetments to smaller canals with the same blockage ratio will generally result in a conservative design, even though the ships, draughts and bank distances are correspondingly smaller than in standard profiles. A separate hydraulic design is generally required if ungrouted revetments are installed on cross-sections with lower blockage ratios, such as those intended for one-way traffic, as the loads due to the return current, bow thrusters and, for water depths less than 4 m, to the propeller wash caused by the main propulsion units may be greater than those in standard profiles.

A value of 97 % of the critical ship speed has been specified as the design speed. It takes economic con- siderations into account, including the behaviour of shipping and the dimensioning of the revetment.

Individual revetment designs in accordance with the Principles for the Design of Bank and Bottom Protec- tion for Inland Waterways /GBB/ are required if the geometrical, hydraulic and geotechnical boundary conditions differ from those on which the standard designs are based. The boundary conditions under which the methods of construction described in this Code of Practice apply are detailed in section 3 to enable designers to ascertain whether an individual design is necessary.

All standard methods of construction are technically equivalent unless further restrictions are explicitly stated. The choice of construction method will be based on technical and economic criteria.

The Codes of Practice "Use of Geotextile Filters on Waterways" /MAG/ and “Use of granular filters on waterways” /MAK/ apply to the design of filters required for the standard methods of construction. In addition, the Code of Practice “Use of Cement Bonded and Bituminous Materials for Grouting of Armourstones on Waterways” /MAV/ applies to grouted revetments. Information on the execution of linings is given in the “Recommendations for the use of lining systems on beds and banks of waterways”

1 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

/EAO/. The Supplementary Technical Contract Conditions – Hydraulic Engineering for Embankment and Bottom Revetments (Section 210) /ZTV-W 210/ apply to the tendering procedure and to execution. In all cases, the latest versions of the above publications shall apply.

2 Terms and Definitions

Some of the principal terms used in this Code of Practice are explained below. Other important terms are defined in /GBB/.

Armour layer: Upper erosion-resistant layer of a bank or bottom revetment. In standard methods of construction the armour layer consists of a layer of armourstones.

Armour layer thickness: Thickness of the armour layer dD, measured perpendicular to the lower or upper edge of the layer (without a filter or impervious lining).

Bank and bottom protection (system): Permeable or impermeable revetment installed on a waterway to ensure that the geometry of the cross-section is maintained.

Blockage ratio: Ratio, n, of the cross-sectional area of a waterway at a particular water level, A, (which affects the return flow) to the cross-sectional area, of the submerged midship section of a vessel, AM (n =

A/AM,)

Bow-heavy: Used to describe a ship laden such that the bow is immerged to a greater depth than the stern. In this case, it is the bow dimensions that are decisive for the design of bank and bottom revetments.

Critical ship speed, vkrit: Speed of a ship in shallow water or in a canal at which the water displaced by the vessel is prevented from flowing fully in the opposite direction to the ship and past its stern. The tran- sition from subcritical to supercritical flow begins (the Froude number in the narrowest cross-section adjacent to the vessel being equal to 1). In general, displacement craft cannot exceed vkrit. Any attempts by displacement craft to travel faster than vkrit, e.g. by increasing the driving power, generally result in even higher return flow velocities and in a greater drawdown than at vkrit, causing the speed of the vessel over ground to diminish and/or the vessel to be drawn towards the bed of the river or canal.

Dynamic underkeel clearance: Difference between the water depth and the draught of a moving ship (sailing draught). The latter is the sum of the draught and the squat.

Excess pore water pressure: Water pressure in the pores of a soil that exceeds the hydrostatic pore water pressure. Excess pore water pressure occurs when the volume of the pore water is prevented from increasing (if the pore water pressure changes) or when the volume of the granular structure is prevented from decreasing (if there are changes in the total or effective tension in the granular structure). It is caused, amongst other things, by rapid water level drawdown. As a result, the pressure in the subsoil will be higher than that at the water/soil interface.

Filter: The purpose of a filter (comprising a geotextile or aggregates (granular filter)) is to retain soil under all possible hydraulic conditions (mechanical filtration stability: protection against erosion). At the same time, it must permit the passage of groundwater without any rise in the seepage line (hydraulic filtration stability).

2 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

Freeboard: Distance between the highest possible water level (upper operating water level, plus any safety margin required) and the lowest point on the bank that must not be overtopped.

Grout: Construction material applied as a liquid and which hardens over time, the setting period being dependent on the material.

Hydraulic loading: The interaction between a ship and the waterway causes a displacement flow around the ship’s hull which is accompanied by the bow wave, the generation of diverging waves at the bow with a short wave period, water level drawdown adjacent to the ship, the generation of transversal stern waves with a short wave period and a slope supply flow which restores the surface of the water to its undis- turbed level. The sequence of bow waves, water level drawdown and transversal stern waves corresponds approximately to the length of the ship and is known as a primary wave (primary wave system). The waves with short wave periods generated at the bow and stern are referred to as secondary waves (secondary wave system).

Lane: Width required by a moving ship within a channel for nautical and hydrodynamic reasons.

Manoeuvring area: Area of a canal or waterway in which ships change course, slow down or accelerate, including turning basins, mooring points, lock waiting areas and loading/unloading facilities.

Minimum armour layer thickness: In addition to the thickness of the armour layer obtained in the geotechnical design calculations, a certain minimum thickness is required to take account of impacts by shipping, the stability of the layer of dumped armourstones and the variations in its uniformity, anchor cast, the type of filter used or other technical aspects. (For values, see /GBB/, sections 6.9 and 6.11, and /Kayser 2005/). The greater armour layer thickness shall apply.

Partial/full grouting: Partial grouting consists of partially filling the voids between the armourstones with grouting material, full grouting of filling the voids completely with grouting material.

Primary wave:  Hydraulic loading.

Revetment: Overall structure of a bank and bottom protection system including the armour layer, the filter and, if necessary, an impervious lining with a separation layer, but not the underlayer, if used. Permeable revetments permit unhindered water exchange between the subsoil and the waterway. They generally comprise an armour layer placed on a filter. Impermeable revetments prevent the exchange of water between the waterway and the subsoil. They may comprise a permeable armour layer placed on an impervious lining, the two being separated by a geotextile separation layer, or an impermeable armour layer placed on a geotextile separation layer.

Secondary wave:  Hydraulic loading.

Separation layer: Separation layers prevent the mixing of different granular layers and erosion. In contrast to filters, their hydraulic filtration stability is of minor importance (e.g. non-cohesive soil on soft to pulpy ground, armourstones on a clay liner, inflexible lining on erosion protection). At the same time, separation layers may promote the self-healing of defective impervious lining systems.

Stability of the armour layer: The individual stones in riprap armour layers must interlock in order to ensure that the rock armour is stable. A minimum thickness is therefore required, irrespective of the de-

3 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

sign calculations (for values, see /Kayser 2005/). Interlocking stones are a prerequisite for the use of the equations for the sizing of individual stones given in /GBB/.

Standard method of construction: Standardized construction method which can be applied under certain specified boundary conditions without separate verification by calculation.

Stern-heavy: Used to describe a ship laden such that the stern is immerged to a greater depth than the bow. In this case, it is the stern dimensions that are decisive for the design of bank and bottom revetments. Generally speaking, ships are stern-heavy when sailing empty or with ballast at the stern (to ensure that the propeller is completely submerged).

Toe protection: Lower part of a slope revetment in the absence of a bottom revetment.

Vegetation cover: This may consist of one or both of the following:

(1) Grasses and herbs native to the locality (or legumes for a first soil improvement) sown on the bank slopes. Vegetation may also become established as a result of natural seed dispersal, plant material being deposited by currents or waves, hay containing ripe seeds being spread over the slopes or by planting sods or depositing soil containing seeds.

(2) Woody plants (including cuttings), reeds or herbaceous perennials planted on the bank slopes.

Water level drawdown/drawdown velocity: Vessels in motion cause the water to flow around them in a particular way which results in the lowering of the water level adjacent to the vessel. Drawdown occurs along the entire length of the ship. The water level drawdown at the banks of the waterway and the associated drawdown velocity are relevant for design.

Zone of fluctuating water levels: Zone on a canal slope which is subjected to the highest hydraulic loads (bow and stern waves, positive surge and drawdown due to lockage operations, wind waves). In the context of this Code of Practice, the zone of fluctuating water levels extends from 1.0 m below the lower operating water level, BWu, to 0.7 m above the upper operating water level, BWo.

3 Boundary Conditions for Standard Construction Methods

3.1 General

The standard construction methods apply when certain boundary conditions in respect of

 the types of ships using a waterway (see section 3.2)

 the waterway cross-sections (see section 3.2) and

 the ground conditions (see section 3.4) are satisfied. They are based on the Principles for the Design of Bank and Bottom Protection for Inland Waterways /GBB/.

Certain assumptions on the characteristics of the ships and the armourstones are made to facilitate the calculation of the hydraulic actions and for design purposes. The parameters subsequently selected are listed in Annex 3.1.

4 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

Armourstones of various size classes and densities as defined in section 4.1 and grouting materials as defined in 4.2 are taken into account.

Geotextiles or granular filters in accordance with section 4.3 may be used as filters.

The impermeable linings used in the standard methods of construction may be tried-and-tested flexible or inflexible linings as defined in section 4.5, combined with a separation layer as defined in section 4.4.

3.2 Types of vessel and hydraulic loads

The standard methods of construction are based on common types of inland waterway vessel with the standard dimensions shown in Table 3.2-1, i.e.:

 Europe ships (ES)

 large self-propelled barges (GMS)

 push-tow units (SV)

 very large self-propelled barges (üGMS).

These types of vessel cover the usual spectrum of ships to be found on Class Vb inland waterways. The cargo of fully laden ships (with the maximum draught permitted for canals) is usually evenly distributed over the vessel. Empty ships or ships sailing with ballast are assumed to have a stern-heavy trim. It should be noted that the coefficient CH, which reflects the influence of the type of ship, the degree of loading, the trim and the water surface gradient, is considered in relation to the ratio of draught to water depth, T/h, (see Annex 3.1) in the basic calculations performed here.

Table 3.2-1: Dimensions of ship types

Draught Length Width T [m] Type L [m] B [m] Fully laden* Empty Bow/stern Bow Stern Europe ships (ES) 85 9.50 2.50 0.70 1.40 Large self-propelled 110 11.45 2.80 0.80 1.60 barges (GMS) Push-tow units (SV) 185 11.45 2.80 0.60 1.60 Very large self-propelled 135 12.00 2.80 0.90 1.80 barges (üGMS) *max. permissible draught for canals

Certain types of vessel such as tugs or pusher craft sailing alone are not considered as they are generally seen quite rarely on inland waterways. However, the potentially greater loads occurring in canal sections in which such craft account for a significant proportion of vessels must be taken into account as specified in /GBB/, in particular where such vessels can be assumed to travel at speeds close to the critical ship

5 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

speed, similar to the types of vessel referred to above. Such loads result from the possible superpositions of bow and stern waves or of primary and secondary waves which are not relevant for the types of vessel in standard canals shown in Table 3.2-1. Higher loads must also be taken into account if the waterways are frequently used by very large motor yachts assumed to travel close to sliding speed.

Loads caused by typical recreational craft are generally lower than those caused by the types of vessel referred to in Table 3.2-1 and are covered by the standard methods of construction. The greater run-up height of secondary waves, in particular those due to recreational craft, is taken into account when the freeboard is specified (see section 5.5).

It is assumed that only ship-induced currents in the waterway are relevant for design purposes. The ship speed over ground may be taken as being equal to the ship speed through the water.

As recommended in /GBB/, a ship speed of 97 % of the critical speed is assumed for design purposes. The value corresponds to the typical measured maximum ship speeds that have been observed irrespective of the permissible ship speeds. It reflects the behaviour of inland navigation vessels on canals. Cases in which the critical ship speed is reached or exceeded only occur very rarely and are locally limited so that they do not constitute standard design situations.

Tables with the most important hydraulic loads for the above ship speeds in trapezoidal and rectangular- trapezoidal profiles are given in Annex 3.2. The ship speeds shown in the tables may be lower than the permissible ship speed, vzul, stated in the German Regulations for Navigation on Inland Waterways /BinSchStrO/ if the blockage ratio (ratio of the waterway cross-section to the cross-section of the ship) is low, e.g. in the case of large self-propelled barges in T-profiles. The opposite case, in which the values of

97 % of the critical ship speed, vkrit, exceed the permissible ship speed, vzul, can occur when the blockage ratio is high (ships with small cross-sections). Revetment designs as specified in /GBB/ are required for ship speeds other than 97 % of the critical ship speed.

The ship’s position is taken to be the most unfavourable path of a fully laden vessel travelling close to the bank. In the case of T-profiles the ship is assumed to be travelling 1 m over the toe of the slope at the edge of the navigation channel in accordance with the “Directives for the Standard Cross-Sections of Canals for Inland Shipping” /RiReS/. An example of a fully laden large self-propelled barge is shown in Figure 3.2-1. The same position has been assumed for unladen vessels on the basis of field tests.

In the case of RT-profiles it has been taken into consideration that the available width of the navigation channel at the level of the relevant draught of the moving vessel is greater than for T-profiles. Further- more, the distance to the design bank in RT-profiles is taken to be 1.5 m greater than in T-profiles in keeping with field investigations which revealed greater bank distances in the former.

6 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

Figure 3.2-1: Example of the most unfavourable position of a large self-propelled barge or push-tow unit at full draught in a T-profile

The greatest hydraulic loads usually occur when single vessels are travelling along a waterway. It can be assumed that the loads will be lower when vessels pass or overtake each other owing to the reduced speeds and changes in the blockage ratios that occur in such situations.

Exceptions are loads due to the propulsion and steering units of ships which are greater when ships pass each other than when craft are travelling alone. However, they do not generally reach values that would be relevant for design.

Evaluations of recent measurements of propeller wash at the bottom of waterways have shown that modern large self-propelled barges – single-screw vessels, in particular – generate wash velocities of around 3.0 m/s close to the bottom of a waterway when sailing at the permissible dynamic underkeel clearance on reaches. In this case, the scour depths caused by individual ships are likely to be less than 0.2 m if the 3 revetment comprises riprap of class LMB5/40 with a density of 2650 kg/m . A value of 0.2 m, which is the maximum scour assumed to occur, is locally acceptable. Greater, accumulated scour depths are unlikely on reaches as local increases in the propeller wash loads will not always occur at the same points.

Theoretical calculations assuming extreme values performed in accordance with /GBB/ and measurements performed for large ships have shown that propeller wash velocities of up to around 5.0 m/s may occur close to the bottoms of waterways during manoeuvring operations. The associated scour depth in a bed revetment comprising riprap of class LMB5/40 would be equal to the thickness of the armour layer. Modified construction methods are therefore required for canal sections in which manoeuvring operations are frequent. For example, a greater water depth could be selected or a partially grouted armour layer installed.

3.3 Waterway cross-sections

The standard methods of construction apply to the two principal types of standard canal profile, i.e.

 the trapezoidal profile (T-profile) and

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 the rectangular-trapezoidal profile (RT-profile).

Details of the dimensions are laid down in the “Directives for the Standard Cross-Sections of Canals for Inland Shipping” /RiReS/. The basic geometry of each profile is summarized in Table 3.3 1.

Table 3.3-1: Geometry of the standard canal profiles N.B: Only the first bank is considered for the revetment design.

Slope inclination Width at water level Water depth 1 : m Profile bWS h 1st bank 2nd bank [m] [m] [-]

T 55.0 4.00 1:3 1:3

RT 48.5 4.00 1:3 

A further profile, known as the combined rectangular-trapezoidal profile (KRT-profile), is also in use. The sides of the KRT-profile below water-level are vertical while those in the zone of fluctuating water levels are sloped /RiReS/ (see section 6.2 for guidance on execution).

The standard methods of construction are based on the lower operating water level, BWu, which is regarded as representative and at which the assumed canal water depth is 4 m. Greater depths result in lower loads at the same ship speed and are therefore generally speaking not relevant for design.

3.4 Ground conditions

The armour layer thickness required to ensure the local stability of a slope is significantly influenced by the type of in-situ ground beneath the revetment /GBB/. The standard methods of construction described in section 5 apply to five different types of soil:

B1: sands and gravels

B2: sands

B3: silty sands and gravels

B4: silts, highly silty sands and gravels

B5: cohesive soils

Apart from the shear strength, the permeability of the soil is of particular relevance to revetment design. The excess pore water pressure beneath a revetment due to water level drawdown close to the slope caused by passing ships, and its destabilizing effect on the revetment and the subsoil, are inversely pro- portional to the permeability of the in-situ soil. However, this only applies to cohesionless soils (B1 to B4).

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If a soil permanently retains an effective cohesion, c‘k, of at least 3 kPa, even under water, it may be assumed that the local stability of permeable revetments (on cohesive soil, type B5) will not generally require verification in accordance with section 7.2 of /GBB/. The minimum armour layer thicknesses apply in such cases. The standard methods of construction do not apply if the effective cohesion is 0 < c‘k < 3 kPa, and in such cases revetments must be designed in accordance with /GBB/. For conservative de- -6 signs, a type B4 soil can be assumed if the cohesion is 0 < c‘k < 3 kPa and the permeability is 5·10 = kk = 1·10-6 m/s.

The mechanical soil parameters of soil types B1 to B5 on which the standard profiles are based have been summarized in Table 3.4 1 to facilitate classification of the in-situ soil. The classification is based on the fines content (d5, d10, d15), also shown in Table 3.4-1, which is the main factor determining the characteristic permeability, kk, of the soil. The design calculations for the standard methods of construction were performed with the lower values of the coefficient of permeability shown in Table 3.4-1.

Table 3.4-1: Characteristic soil parameters for soil types B1 to B5

Soil Descrip- Coefficient of per- Effective Effective Wet Specific Particle diameter di tion meability angle of cohesion specific weight at i-% passing sieve friction weight under buoyancy

kk k' ck' k k' d5 d10 d15 [m/s] [°] [kN/m²] [kN/m³] [kN/m³] [mm] [mm] [mm]

Sands -4 B 1 and kk ≥ 5·10 35.0 0 19 11  ≥ 0.2  gravels

-4 -5 B 2 Sands 5·10 > kk ≥ 5·10 35.0 0 19 11  ≥ 0.07 

Silty sands -5 -6 ≥ B 3 5·10 > k ≥ 5·10 32.5 0 18 10 ≥ 0.02  and k 0.002 gravels Silts, highly 0 silty ≥ ≥ B 4 5·10-6 > k ≥ 1·10-6 30.0 (0

and gravels

Cohesive -6 < < B 5 1·10 > k < 30.0 c ' ≥ 3    soils k k 0.002 0.02

9 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

4 Revetment Components

4.1 Armourstones

The requirements for armourstones used in revetments are laid down in the European Standard EN 13383-1 - Armourstone, Part 1: Specification /DIN EN 13383-1/. The current edition of the Technical Sup- ply Conditions for Armourstones /TLW/ also applies.

EN 13383-1 specifies various standard size classes with different resistances to hydraulic actions. Small armourstones are defined by the sieve perforation size, D, (size of the square perforations) and are referred to as class CPx/y (Coarse Particle, x being the lower class boundary [mm] and y the upper class boundary [mm]). The larger classes are defined by the weight, G, of the stones as light gradings LMx/y

(Light Mass, x = lower class boundary [kg], y = upper class boundary [kg]) or heavy gradings HMx/y (Heavy Mass). The stones used in armour layers for revetments on inland waterways generally belong to classes CP90/250, LMB5/40 and LMB10/60 /Kayser 2005/.

In addition to the provisions of EN 13383, the design value obtained in the hydraulic design of revetments with riprap armour layers in accordance with /GBB/ is the value below which 50 % (by weight) of the stone fraction lie (G50 for weight classes and D50 for size classes). G50 is shown for a stone fraction of class LMB5/40 (indicated in red) in Figure 4.1-1. G50 is also given for an average stone fraction (indicated in green) which is defined by the line drawn between the nominal upper and lower boundaries.

Apart from the required G50 (D50)-value, the cumulative curve according to EN 13383 must lie within certain boundaries. An example for class LMB5/40 is shown by the hatched area in Figure 4.1-1.

Figure 4.1-1: Definition of the design values G50, shown here for class LMB5/40

The armourstones used must at least satisfy the 50 %-value of the mean cumulative curve (log-linear line connecting the nominal class boundaries, see the green line given as an example in Figure 4.1-1). This value must be checked during construction if such a check is specified in the contract. Guidance on how to determine D50 and G50 is given in Annex 4.1-1.

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The values of D50 and G50 for the most frequently used size classes are given in Table 4.1-1. The boundaries mean cumulative curves and usual ranges of fluctuation of the size classes are shown in An- nex 4.1-2. The procedure for selecting the size class described in section 5.2.1 is based on those values.

Table 4.1-1: 50 %-values for the standard size classes for riprap armour layers

Size class 50 % - value

CP90/250 D50 = 150 mm

LMB5/40 G50 = 14 kg

LMB10/60 G50 = 25 kg

The standard methods of constructing armour layers are specified for four different stone densities, s, i.e. for 2300 kg/m3, 2650 kg/m3, 3000 kg/m3 and 3600 kg/m3.

4.2 Grout

Impermeable cementitious grouting materials are recommended. Compared with partial grouting with impermeable grouting materials, the use of water-permeable grouting materials is very limited. Bitumi- nous grouting materials (asphalt) are not dealt with in the description of the standard construction methods as they are no longer used on inland waterways in Germany for economic reasons and as they are difficult to install under water. Guidance on the recommended quantities of grouting material is given in /MAV/ which also lays down the requirements for the raw materials, the required tests and installation.

4.3 Filter layers

The standard requirements for geotextile filters are specified in /TLG/ and /ZTV-W LB 210/ and the requirements for aggregate (granular) filters are set out in /ZTV-W 210/. Granular filters are generally un- bound. The use of bound granular filters should be limited to the protection of relatively small areas which can be easily inspected. Guidance on filter design is given in /MAG/ and /MAK/.

4.4 Separation layers

Depending on the application, aggregates as specified in /MAK/ or geotextiles as specified in /MAG/ and /TLG/ may be used as separation layers. Separation layers between flexible linings and armour layers do not act as hydraulic filters. If a separation layer is installed beneath an impervious lining, its water permeability must be lower than that of the adjacent soil.

4.5 Impervious lining systems

4.5.1 General

The impervious linings used in the standard construction methods are all surface linings. Detailed guidance on the various impervious lining systems, their characteristics and the limits of their application is

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given in /EAO/. Vertical linings and the impervious cores of embankments are not covered by the standard methods of construction as they do not form part of the revetment.

4.5.2 Flexible lining systems

The following types of flexible lining are used on waterways:

 natural clay liners

 permanently plastic linings with clay and hydraulic binders

 geosynthetic clay liners (GCL).

The material requirements and tests on flexible linings shall be as specified in /RPW/ and /EAO/.

The specifications of /TLG/ and the recommendations given in /MAG/ that are relevant to impermeable linings also apply to GCLs.

4.5.3 Inflexible lining systems

The only inflexible lining systems included in the standard methods of construction are those comprising armourstones fully grouted with an impermeable cementitious grouting material as specified in /MAV/ and /EAO/. Guidance on the recommended quantities of grouting material is given in /MAV/ which also in- cludes the requirements for the constituent materials, the required tests and installation.

5 Standard Methods of Construction

5.1 General

Revetments constructed by means of the standard methods may be permeable or impermeable, depending on the design. A separate lining may be placed beneath a permeable armour or separation layer, or the armourstone armour layer may be fully grouted with an impermeable material. Any decision on the need for a sealing system in a revetment must take hydrogeological and safety aspects into account (see section 5.6.2).

Embedding the revetment to a depth of 1.5 m below the bottom of the waterway is a tried-and-tested method of toe protection. Under certain boundary conditions the embedment depth may be reduced or a toe blanket installed (see section 5.3).

A bottom revetment is generally only required if certain components or structures need to be protected, e.g. impervious lining systems, inverted siphons just beneath the bottom of the waterway or sheet piling at moorings. It must be checked whether there is a need for bottom revetments in manoeuvring areas.

The local stability (in accordance with sections 7.2, 7.3, 9.2 and 9.3 of /GBB/) of the standard methods of construction described below will be ensured if the actions due to ship-induced waves and to currents are taken into account in accordance with the design principles (see section 3) and the effects of anchor cast are also considered. The global stability of water-side slopes protected by standard revetments shall be verified, taking into account the relevant imposed loads detailed in section 7.4 of /GBB/.

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The weight of the granular filter is fully taken into account in the mass per unit area in the geotechnical design calculations. Significant structurally unfavourable excess pore water pressures do not occur in granular filters. Stability is governed by the overall thickness of the armour layer and granular filter. This has been taken into consideration in the standard methods of construction described below.

The weight of armourstone armour layers is governed to a considerable extent by the void ratio of the layers which mainly depends on the method of installation. Values based on experience are given in Ta- ble 5.1-1.

Table 5.1-1: Void ratio of armourstone armour layers as a function of the method of installation (based on depth measurements taken at the highest points of the armourstones)

In-situ density Void ratio, n Method of installation

loose 50 - 55 % The armourstones are dumped under water. The armourstones are either dumped in dry conditions or medium 45 % placed directly on the subgrade by an excavator. The armourstone layer is finished manually or compacted dense 30 - 40 % by the placement equipment.

The above empirical values apply to armour layers with the thicknesses specified in section 5.2 obtained by depth measurements taken at the highest points of the armourstones (e.g. depth measurements performed with a frame or a conventional staff with a plate foot with a diameter of around 30 cm or higher). Measurements performed with spherical foot staffs are also common. In this case, the depth is measured in the gaps between the top layer of stones instead of at the highest point of the stones. The layer thicknesses and void ratios obtained by depth measurements performed with a spherical foot staff are lower than those obtained with a conventional staff (cf. section 8.2). If spherical foot diameters of 9 cm for

CP90/250, 12 cm for LMB5/40 and 15 cm for LMB10/60 are used, the upper edge of the revetment will be around 3 cm to 5 cm lower than that measured at the highest points of the armourstones,

The standard methods of construction described below are based on a void ratio of 50 % as shown in Table 5.1-1.

The requirements set out in /MSD/ for vegetation cover on the embankments of canals built above the level of the surrounding countryside must be taken into consideration.

Revetments that do not extend over the full height of the slope (partial revetments) are not covered by the standard methods of construction as they are customized solutions for particular ground conditions, e.g. where the lower slope consists of bedrock, rendering it unnecessary to protect the complete slope. If the lower edge of the partial revetment is embedded in the rock the armour layer thickness of the corresponding standard method of construction may be adopted to provide a conservative design.

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5.2 Armour layers

5.2.1 Permeable armour layers comprising riprap

This standard construction method comprises an armour layer of riprap as defined in section 4.1 placed on a granular or geotextile filter.

Figure 5.2.1-1: Diagram of the cross-section of a permeable armour layer of riprap

Permeable armour layers comprising riprap readily adapt to ground deformations (flexibility). They have sufficient resistance to ship collisions provided such collisions occur largely parallel to the axis of the canal.

The stability of revetments constructed by this method depends largely on the size of individual stones and the thickness of the installed armour layer. These factors are dependent on the density of the stones and the void ratio of the armourstone layer. Limited movement or even local displacements of stones may occur under the loads assumed in the design and are taken into account in the calculations for standard designs in /GBB/ (stability coefficient, B’B, = 2.3, see eq. (6-3) /GBB/). A limited degree of maintenance work may therefore be required. Any damage to the revetments should be repaired as soon as possible. The standard methods of constructing riprap revetments described in this Code will not ensure sufficient stability (see section 5.6.5) if high flow loads occur in the vicinity of a revetment (e.g. in manoeuvring areas, waiting areas and at mooring points). The same applies to temporary moorings constructed for the duration of the execution of the works.

The size of individual stones required for this particular standard construction method ensures that surface erosion due to breaking waves, return currents, slope supply flow and propeller wash, if relevant, is limited. It does not depend on the in-situ soil but solely on the hydraulic loads referred to. The required mean sizes, D50, or mean weights, G50, of the individual stones and the resulting recommended stone sizes determined in accordance with section 4.1 are given in Table 5.2.1-1 as a function of the density of the stones. Ripraps with the required D50- or G50-values ensure that individual stones possess an adequate degree of stability for the loading scenarios described in section 3.

Beyond Table 5.2.1-1 it may in certain circumstances be useful to select the next lowest size class. How- ever, the lower size class must also comply with the value of D50 or G50 required for the relevant density and the value should be within the range of variations typical of the relevant class as shown in Annex 4.1- 2. This represents a higher requirement for the next lowest size class and may therefore limit its application.

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The minimum thicknesses of the riprap armour layer required to ensure the stability of the revetment will increase for a particular density of stone as the size class increases (see Annex 5.2.1-3). For this reason, it may be appropriate to consider whether the next lowest size class with a G50- or D50 –value greater than the mean value of that class should be used.

Density Required value Required value Recommended

S of D50 of G50 size class [kg/m3] [mm] [kg] -

2300 ≥ 260 ≥ 25 LMB10/60

2650 ≥ 200 ≥ 14 LMB5/40

3000 ≥ 160 ≥ 8 LMB5/40

3600 ≥ 120 ≥ 4 CP90/250

Relatively large stones and correspondingly thick layers are always required in the case of densities, s, 3 3 less than 2650 kg/m . Generally speaking, the density, s, should be not less than 2650 kg/m .

For intermediate density values, either the stone size for the next lowest density should be selected for conservative designs or verification by calculation should be performed with the exact density as specified in /GBB/.

As a rule, densities greater than 3000 kg/m3 can only be achieved with manufactured armourstones (slags). If such armourstones are used, provisions on environmental impact must be taken into consideration.

After the size class and density of the stones have been specified, the recommended thickness of the armour layer must be selected from Table 5.2.1-2, taking the soil and type of filter into consideration. However, the recommended thicknesses of armour layers on flexible linings only correspond to the specified minimum thicknesses if the groundwater level is lower than the canal water level when lowered by shipping. If this is not the case, the safety against uplift must be verified (see Annex 5.6.2-1).

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Table 5.2.1-2: Recommended armour layer thicknesses (riprap) for slope and bottom revetments, taking account of the soils specified in 3.4

Recommended armour layer thicknesses, dD [m]

for revetments with an embedded toe (embedment depth: 1.50 m)

Density Armourstone Slope Bottom 3 [kg/m ] size class Granular filter Geotextile Granular filter Geotextile as specified in as specified in as specified in as specified in MAG MAK MAG MAK

B1, B2, B5* B3 B4 All soils All soils All soils

2300 LMB10/60 0.70 0.85 0.95 0.70 0.70 0.70

2650 LMB5/40 0.60 0.70 0.80 0.60 0.60 0.60

3000 LMB5/40 0.55 0.60 0.70 0.55 0.60 0.55

3600 CP90/250 0.50 0.50 0.60 0.50 0.60 0.50

*B5 including flexible linings

In addition to the armour layer thicknesses specified in Table 5.2.1-2, the thicknesses of the armour layers required for slope and bottom revetments if alternative size classes of armourstones are used are shown in Annex 5.2.1-1. The values take into account the armour layer thicknesses obtained by geotechnical calculations for slopes (shown in Annex 5.2.1-2) and the minimum thicknesses for slope and bottom revetments that are required not only to resist ship collision and anchor cast, for example, but also to ensure the stability of the armourstone layer (Annex 5.2.1-3). In each case, the higher value applies and is rounded to the nearest 5/100 [m] in Annex 5.2.1-1 and in Table 5.2.1-2. No distinction has been made between trapezoidal and rectangular-trapezoidal profiles. The recommended armour layer thicknesses are based on mean values obtained from the results calculated for each type of profile.

The specific requirements stated in section 5.4 must also be taken into account in the case of armour layers placed on flexible linings.

If stones with densities between the values stated in Annex 5.2.1-1 are used, the required thickness of the armourstone layer can be interpolated, taking account of the minimum thicknesses shown in the dia- grams in Annex 5.2.1-2.

5.2.2 Permeable armour layers comprising partially grouted armourstones

This standard method of construction comprises a armour layer of dumped armourstones as described in section 4.1, partially grouted with an impermeable grouting material as described in section 4.2. The armour layer may be installed on a granular or geotextile filter.

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Figure 5.2.2-1: Diagram of the cross-section of a permeable armour layer comprising partially grouted armourstones

Permeable armour layers comprising partially grouted armourstones have only a limited degree of flexibility which is governed by the quantity of grouting material used. Collisions by ships may result in damage to the revetment. Any local damage to partially grouted armour layers should be repaired as soon as possible as it may otherwise become enlarged.

The execution of grouting work under water must be closely monitored /ZTV-W 210/.

The size class CP90/250 is recommended for the construction of partially grouted armour layers. The proportion of fines in the size class must be limited by specifying 90 mm as the minimum value of D5 in the contract documents in order to ensure a sufficiently large void size. Stones of class LMB5/40 may also be used.

The thicknesses recommended for partially grouted armour layers comprising armourstones of classes

CP90/250 and LMB5/40 placed on soil types B1 to B5 or a flexible lining are stated in Annex 5.2.2-1. The values apply to both bottom and slope revetments and take the density of the stones into account. The armour layer thicknesses obtained in calculations performed for the geotechnical design of the slope (shown in Annex 5.2.2-2) and the minimum thickness, which is usually 40 cm for the size classes used, have been taken into consideration. The higher value, which has been rounded to the nearest 5/100 [m] in Annex 5.2.2-1, shall apply in each case. No distinction has been made between trapezoidal and rectangular-trapezoidal profiles. The recommended armour layer thicknesses are based on the mean values of the results calculated for both types of profile.

The specific requirements stated in section 5.4 must also be taken into account in the case of armour layers placed on flexible linings.

If stones with densities between the values stated in Annex 5.2.2-1 are used, the required thickness of the armourstone layer can be interpolated, taking account of the minimum thicknesses shown in the dia- grams in Annex 5.2.2-2.

5.2.3 Impermeable armour layers comprising fully grouted armourstones

This standard method of construction comprises a armour layer of dumped armourstones as described in section 4.1, fully grouted with an impermeable cementitious grouting material as described in section 4.2. This type of armour layer may only be installed on a geotextile separation layer as described in section

4.4. The weight class LMB5/40 or LMB10/60 is recommended.

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Figure 5.2.3-1: Diagram of the cross-section of an impermeable armour layer comprising fully grouted armourstones

Any underlayers required beneath an impermeable armour layer must be less permeable than the in-situ ground, but must nonetheless be filter-stable. Otherwise there is risk that due to a local damage to the impermeable revetment the hydraulic head of the canal would become distributed over a large area below the revetment, leading to damage due to buoyancy.

Impermeable armour layers comprising fully grouted armourstones have no flexibility. Damage may occur as a result of ship collision. Any damage to impermeable armour layers must be repaired in order to re- store their sealing function.

The minimum thicknesses of impermeable, fully grouted armour layers shown in Annex 5.2.3 are sufficient if the groundwater level is always lower than the canal water level when lowered by shipping. If excess water pressure acts behind the impervious lining, either temporarily or permanently, the thicknesses of the armour layer required to ensure sufficient safety against uplift must be calculated. The required minimum thicknesses and examples of the required armour layer thicknesses obtained by calculation are given in Annex 5.2.3 for various excess water pressures.

5.3 Toe protection

The stability of slope revetments depends, amongst other things, to a great extent on the design of the toe. On the basis of past experience, an embedded toe is recommended for the standard methods of construction. For soil types B2, B3 and B4 defined in section 3.4, the standard methods of construction described in this Code must include an embedded toe with a minimum embedment depth, t, of 1.50 m below the design level of the bottom of the waterway (see Figure 5.3 1). This also applies to cohesive soils (soil type B5) with poor resistance to erosion. The toe trench is generally filled with in-situ soil.

18 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

Figure 5.3-1: Design of the toe protection

Whenever the in-situ soil beneath the revetment is of soil type B1 the embedment depth of the toe may be reduced to 1 m if the armour layer thicknesses specified in Annexes 5.2.1-3 and 5.2.2-2 are maintained or, alternatively, a toe blanket as shown in Figure 5.3 1 is installed. These measures are also possible in the case of bedrock or firm cohesive soils (B5) that are resistant to erosion.

The standard methods of construction do not consider scour directly at the toe of the slope as experience has shown that scour caused by shipping only occurs at a distance of several metres from the toe. Never- theless, if any local scour should occur directly at the toe of the slope it must be remedied during maintenance work. Alternatively, the depth of the toe protection beneath the bottom of the waterway may be extended by increasing the standard depth of 1.5 m by the forecast depth of the scour or the toe trench may be filled with material that is coarser than the in-situ soil, such as gravel. The material must prevent loss of the in-situ soil. Revetments may also be designed individually in accordance with /GBB/ to take scour into account.

Excavation of a toe trench in highly erosive soils such as soil type B4 may be difficult. In such cases, very low slope inclinations should be selected for the toe trench and the revetment should be installed immediately after the trench has been excavated.

Sheet pile walls are only installed at the toe in exceptional cases and are therefore not considered in the standard methods of construction. The actions and resistances on the sheet pile wall must be determined as specified in /GBB/. The armour layer thicknesses specified for the standard construction methods in this Code of Practice may be used to achieve a conservative design. Sheet pile walls are stable in the long term but are a relatively costly method of toe protection. They can only be constructed in driveable

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soils without obstacles to driving such as the remains of previous revetments. The connection between the slope protection and the head of the sheet pile wall must be filter-stable. Scour to depths of 1.50 m (for soil types B2 to B4, depending on the resistance to erosion, but also for soil type B5) or of 0.75 m (for soil type B1) in front of the sheet pile wall must be taken into account in designs in accordance with section 7.2.5.5 of /GBB/.

5.4 Flexible linings

Permeable revetments comprising riprap or partially grouted armourstones (see sections 5.2.1 and 5.2.2 respectively) may be installed on a flexible lining as described in section 4.5.2. The use of underlayers that are more permeable than the in-situ soil is not permitted as the development of any seepage paths in the plane beneath the flexible lining must be avoided. There is otherwise a risk that the pressure potential of the water in the canal could become distributed over a large area below the lining if local damage to the lining occurs, leading to damage due to buoyancy.

If clay liners are used, only geotextile separation layers as described in section 4.4 should be installed between the lining and the armourstones. If granular filters are used there is a risk that any defects in the lining occurring after installation of the clay may become filled with filter material, resulting in permanent seepage points. By contrast, minor defects in the clay liner can “heal“ due to the superimposed load of the armour layer.

Owing to the lack of experience with geosynthetic clay liners (GCLs) and permanently flexible linings with clay and hydraulic binders, their use is currently only recommended for low-risk canal sections higher than the surrounding ground surface which do not require frequent monitoring /EAO/. Up-to-date information on the use of such liners can be found in articles published by the BAW (BAW-Brief publications) or on the BAW website (www.baw.de).

Geosynthetic clay liners are generally installed with a sand mat (a geotextile filled with sand or a mineral material to weigh it down). The armourstones placed on GCLs may not exceed class LMB5/40, without oversized pieces of stone, in order to minimize any local unevenness of the bentonite layer caused by the impact of the armourstones during installation.

Permanently flexible linings with clay and hydraulic binders cannot be installed on inclined surfaces owing to the flowing properties of the materials.

5.5 Freeboard height

Slope revetments should extend to a height of at least 70 cm above the relevant design water level to take account of possible wave run-up. The design water level will either be the upper operating water level, BWo, or the highest navigable water level, HSW.

5.6 Selection of a standard method of construction

5.6.1 General

The choice of a standard method of construction is influenced by the local boundary conditions (e.g. ground, topography, groundwater table) and the requirements (e.g. for loads due to shipping, actions due

20 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

to leisure activities, environmental impact) that the revetment needs to satisfy. The correct balance between the various, possibly opposing, factors must be achieved. The following points must be considered or specified when selecting a standard method of construction.

5.6.2 Requirement for an impervious lining

An impervious lining may need to be installed on a waterway if the lowest operating water level of a canal is higher than the highest level of the groundwater table, i.e. there is a permanent hydraulic gradient between the canal and the groundwater (see top diagram in Figure 5.6 1). The following aspects must be considered: a) safety of the embankment (achieving an adequate level of safety in load case 1), b) waterlogging of adjacent land or flooding of buildings, c) high seepage losses (standard value of permissible seepage losses based on the cost of replacing lost water: 15 l/s/km), d) adverse effects on drinking water reservoirs.

Sufficient groundwater data is needed to determine whether an impervious lining is required. The data is also needed for the preservation of evidence.

Possible methods of constructing the transitional zone between an impervious lining and the permeable sections of a revetment are shown in Figure 5.6-1 (centre) and must be considered if an impervious lining is to be installed. It must be taken into account that impervious linings may be exposed to land-side excess water pressure if installed in the transitional zone between a cutting and a canal section built above the level of the surrounding ground surface or if the groundwater and canal water levels are subject to large fluctuations. The thickness (or weight) of the armour layer will then need to be calculated as specified in section 7.3 of /GBB/ and the resulting layer thicknesses may be high. Examples of the thicknesses of armour layers placed on clay liners and GCLs that are required to take account of a range of excess water pressures are shown in Annexes 5.6.2-1 and 5.6.2-2 (for riprap and partially grouted armour layers respectively). Irrespective of this, the minimum thicknesses specified in Annex 5.2.1-3 or Annex 5.2.2-3 must be taken into account.

Alternatively, the groundwater level can also be limited to a structurally acceptable maximum level by technical measures (e.g. drainage, wells) (cf. Case a) in Figure 5.6 1, centre). The possible environmental impact of such measures must be considered.

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Selection criterion Type of revetment

BWu max. GW

BWu > max. GW Impermeable revetment, if appropriate

a.) Impermeable revetment, if appropriate BWu ≤ max. GW If the groundwater level is limited to the maximum permitted max. GW BWu value obtained in the verification of safety against uplift (section 7.3.3 of /GBB/) at the lower operating water level, BW , min. GW u and with the actual or planned weight of the armour layer. b.) Permeable revetment BWo ≥ min. GW Water losses occur and must be acceptable. It must be checked whether the adjacent areas could become water- logged.

min. GW BWo BWo < min. GW Permeable revetment

BWu: lower operating water level

BWo: upper operating water level max. GW: highest anticipated groundwater level min. GW: lowest anticipated groundwater level

Figure 5.6-1: Criteria for the selection of an impermeable or permeable revetment

Impervious linings must extend at least 0.50 m above the upper operating water level (BWo) or the highest navigable water level (HSW).

5.6.3 Soil classification

The required thickness of the armour layer depends to a large extent on the type of ground on which the design of the revetment is based. If different types of soil are present or the soil is stratified, it will be necessary to decide which type of soil the design should be based on. The type of soil (classified as type B1 to B5 in accordance with section 3.4) that is selected must always be the one that results in the greatest armour layer thickness. Thin soil strata (= 1 m) may generally be disregarded.

5.6.4 Requirement for a filter or a separation layer

Reference should be made to either /MAG/ (for geotextiles) or /MAK/ (for granular filters) to determine whether a filter is required for the planned slope or bottom revetment.

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Geotextile separation layers should be installed beneath impermeable armour layers and on top of impervious clay liners. In addition, separation layers are required to prevent any mixing or penetration of layers of different types of mineral particles (e.g. non-cohesive soil placed on soft or pulpy ground).

5.6.5 Selection of an armour layer

If properly executed, the armour layer construction methods described in section 5.2 may be regarded as technically equivalent on reaches and are all applicable in principle. However, each construction method has particular strengths and weaknesses which must be evaluated when a construction method is selected for a specific project. The requirements for construction and operation (execution, resistance, permeability, etc.), for maintenance (ease of inspection, magnitude of damage, cost of repairs), environmental impact and cost-effectiveness (production and maintenance costs) must be considered.

The loads due to the propulsion and steering units of vessels will be relatively high in manoeuvring areas (e.g. mooring points and turning basins, lock waiting areas or areas in which the cross-section radi- cally changes). Such loads result in greater hydraulic actions than on reaches and affect the stability of individual stones. Designs taking these aspects into account would result in armour layer dimensions far exceeding those obtained for the standard methods of construction.

Armour layers comprising partially or fully grouted armourstones (sections 5.2.2 and 5.2.3) are recommended whenever slope or bottom revetments are required to provide protection against scour in manoeuvring areas. Other measures are also possible, such as greater water depths at mooring points or dolphins to ensure a minimum distance between vessels and the banks in order to limit the loads due to bow thrusters.

Acceleration and stopping zones in lock waiting areas must be inspected to determine if there is a risk of scour. In the case of modern vessels, the length of the acceleration area can generally be taken to be around 100 m for self-propelled barges and 200 m for push-tow units. The length of the stopping area required for self-propelled barges and push-tow units may be taken to be around 200 m and 300 m respectively.

6 Other Methods of Construction

6.1 General

Two other frequently-used methods of construction are described in the following sections. They are:

 revetments in combined rectangular-trapezoidal profiles (KRT-profiles) (see section 6.2) and

 impermeable, erosion-resistant pavements (see section 6.3).

Although combined rectangular-trapezoidal profiles are regarded as standard cross-sections /RiReS/ the revetments in such profiles are exposed to lower loads than those in rectangular-trapezoidal or trapezoidal profiles and are therefore not included in the standard methods of construction.

Impermeable pavements used to be installed extensively on waterways. However, they have become less widespread over the past two decades owing to technological and economic developments and are therefore no longer regarded as a standard method of construction.

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Stone-filled wire mesh elements (such as gabions and rock mattresses) have not been included in the standard methods of construction as they are only used to a small extent, mostly in areas with unusual geometrical boundary conditions (e.g. as regards the slope inclinations).

6.2 Revetments in combined rectangular-trapezoidal (KRT) profiles

Revetments in combined rectangular-trapezoidal profiles serve to protect the short slopes above sheet pile walls (see /RiReS/ for standard dimensions) which are exposed to considerably lower hydraulic loads than the slopes in trapezoidal profiles.

The following methods of construction are possible:

 60 cm riprap, minimum class LMB5/40, on a granular or geotextile filter (see section 5.2.1) or

 40 cm partially grouted armourstones of class CP90/250 (quantity of grouting material as specified in /MAV/) on a granular or geotextile filter (see section 5.2.2).

6.3 Impermeable erosion-resistant pavements

Pavements are revetments with a homogeneous structure, uniform thickness and a uniform mass per unit area (e.g. asphalt concrete). Owing to their internal strength, they do not require a protective covering. Pavements may also be armour layers comprising elements of the same type joined together to form a continuous area (e.g. interlocking concrete blocks).

Impermeable erosion-resistant pavements must protect and seal the slopes and the bottom of waterways. They are made of either asphalt or concrete.

Concrete is a rigid material and cannot adapt to deformations of the subgrade. Asphalt possesses a degree of flexibility due to the viscoelastic properties of the bitumen and is able to resist external stresses such as settlements or compressive or shearing stresses to a certain extent, depending on the tempera- ture.

Concrete and asphalt pavements are easily damaged by sudden, high levels of local stress such as ship collisions.

A separation layer must be placed between an impermeable pavement and the in-situ soil or an underlayer, if used. The occurrence of seepage paths in the plane beneath the impermeable pavement must be avoided. Separation layers or underlayers that are more permeable than the subgrade are therefore not permitted beneath impermeable pavements as the pressure potential of the water in the canal would be distributed over a large area beneath the impermeable pavement if the latter suffered local damage. The transient stresses due to the changes in pressure caused by water-level drawdown would then result in extensive damage to the impermeable pavement to a depth of around 1 m below the water level due to buoyancy.

The minimum concrete thicknesses are 15 cm for installation in dry conditions and 20 cm if the concrete is placed under water.

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The recommendations given in /EAAW/ apply to the planning and installation of asphalt pavements for waterways. Generally speaking, they may only be installed in dry conditions.

Impermeable bituminous pavements are susceptible to root penetration. Maintenance work, especially on asphalt revetments, must include the removal of any vegetation.

The safety against uplift must be verified in accordance with section 7.3 of /GBB/ if the groundwater level is high.

7 Vegetation Cover in Standard Methods of Construction

7.1 General

Suitable vegetation should be planted or grown from seed on the banks above the water level in all standard methods of construction for the following reasons:

 to encourage colonization of the banks of waterways by flora and fauna

 to improve natural environments and landscapes

 to increase the stability of the banks by means of root growth

 to provide greater protection of shipping against wind

However, possible adverse effects must also be considered, for example:

 increased maintenance costs owing to care of the vegetation cover

 collapse of banks at the edge of the vegetation cover

 damage to the impervious lining due to root penetration

 increase in the amount of plant debris (plant material or dead plants) in the navigation channel

 decreased visibility for boatmasters due to high vegetation

 reduction in the stability of embankments (see /MSD/).

Generally speaking, the standard methods of construction provide only limited opportunities for vegetation growth. This is due to the specified bank geometries and revetment designs as well as the fact that revetments in the standard cross-sections are exposed to relatively high loads due to shipping.

Vegetation may develop naturally as a result of seed dispersal by the wind or by plant material being washed up and deposited in the silt that accumulates in the cavities between the armourstones. The establishment of vegetation cover may be encouraged and accelerated by covering the armourstone layer with unfertilized topsoil and by sowing grasses and herbs native to the locality or by other means. The topsoil should not only be placed on top of the armourstone layer but should also fill as many of the cavities between the armourstones as possible. However, topsoil is likely to be rapidly washed away in the zone of fluctuating water levels due to the hydraulic actions on the bank. It should therefore only be placed on slopes above a height of at least 50 cm above the normal or mean water level.

25 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

The stability and rate of vegetation growth can be increased if the cavities in armourstone layers are completely filled with alginate-enriched topsoil. The topsoil mixture is produced in specialized mixing plants and consists of finely sieved topsoil to which alginate with montmorillonite colloids (i.e. bentonite) has been added. Mixing the alginate-enriched topsoil with water produces a flowable clay-humus complex with thixotropic properties that can be pumped into the cavities between the stones (see p. 16 of /STLK 207/). When installed, the alginate-enriched topsoil has a higher resistance to erosion than normal topsoil and can therefore be placed in the armour layer directly above the normal or mean water level.

Furthermore, planting woody plants or cuttings (e.g. of shrubby species of willows) or plant plugs (reeds or other herbaceous perennials of around 15 cm in length and diameter, with the root ball frequently wrapped in coir matting) in the unfertilized topsoil or alginate-enriched topsoil placed in the cavities between the dumped stones is recommended where technically feasible and provided that the stability of the revetment is not jeopardized. Plant plugs should be planted in rows parallel to the bank (with the distance between the rows being approx. 30 – 40 cm). The spaces between the plants should also be approx. 30 – 40 cm.

The different moisture requirements of the various types of vegetation must be taken into consideration. Plants such as the common reed or yellow iris thrive in wet conditions such as those found at normal or average water levels and up to around 10 cm to 20 cm above them. Sedges and marshland perennials can grow in slightly drier conditions, but do not thrive particularly well in locations higher than 30 cm to 40 cm above the normal or average water level.

The correct light conditions are also important for successful vegetation growth. Reeds only thrive if there is not too much shade on the banks. Woody plants may adversely affect the growth of grasses, herbs or reeds sown or planted nearby, depending on the light conditions.

Successful vegetation growth depends to a large extent on local conditions so that it is not possible to give any general recommendations on which types of plant to select. It is recommended that vegetation plans indicating suitable types of plants be drawn up by experts.

Generally speaking, plants that are native to the locality and suitable for the site should always be used. Seeds and plant cuttings for a particular revetment should be sourced from the locality in which they are to be used.

Vegetation cover should always extend over continuous areas. Solitary plants may result in local increases in flow loads which would adversely affect the stability of the individual plants.

7.2 Permeable armour layers comprising riprap or partially grouted armourstones as described in sections 5.2.1 and 5.2.2 respectively

The growth of vegetation on permeable armour layers comprising riprap or partially grouted armourstones depends on a variety of factors and boundary conditions. In addition to the points discussed in section 7.1, other important factors include the thickness of the armour layer, the stone sizes, the size of the cavities in the stone layer, the stability of the armour layer, including its resistance to the displacement of stones, and the different wave loads occurring on the various types of waterway.

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Vegetation cover may be established by sowing grasses and herbs native to the locality or planting reeds, herbaceous perennials or woody plants, for example, in topsoil or alginate-enriched topsoil placed on the armour layer (see section 7.1).

Wave action may cause local displacement of the stones in riprap armour layers, resulting in damage to plants. Stone displacement rarely occurs in partially grouted armour layers. On the other hand, the surface on which plants can take root is smaller than in the case of riprap armour layer. Compliance with the recommended quantity and distribution of the grouting material specified in /MAV/ is required in order to optimize the conditions for vegetation cover on partially grouted armour layers.

The opportunities for the establishment of fauna provided by the empty cavities between the stones in the zone of fluctuating water levels and under water depend on the void ratios of the armour layer and stone surface available for colonization, with higher void ratios and a larger available stone surface being more favourable. Compliance with the recommended quantities and distribution of grouting material specified in /MAV/ is therefore an important factor if fauna is to colonize the banks.

7.3 Impermeable armour layers comprising fully grouted armourstones as described in section 5.2.3

Root penetration is generally ruled out on fully-grouted impermeable armourstone revetments owing to the absence of voids in the armour layers. As a result, grass and herbaceous plants are unable to grow on such revetments.

It is not permitted to plant woody perennials or reeds on the slopes, and any vegetation of this kind must always be removed immediately.

7.4 Guidance on vegetation cover on flexible linings

Grasses and herbs may be sown on revetments with flexible linings. Other types of vegetation must be planted at a sufficient distance from the lining (see /MSD/). This is due to the fact that there are several varieties of woody plants and reeds whose roots are able to penetrate flexible linings. Undesirable plant growth on a lining can lead to high maintenance costs. The types of undesirable vegetation that could grow on the lining must be assessed in advance and maintenance planned accordingly.

8 Guidance on Invitations to Tender, Execution of the Works, Quality Control and Maintenance

8.1 General

Invitations for tenders for slope and bottom protection systems must be based on /STLK 210/, taking account of the following codes of practice in particular:

 Code of practice “Use of standard construction methods for bank and bottom protection on inland waterways“/MAR/

 Code of practice “Use of geotextile filters on waterways“ /MAG/

 Code of practice “Use of granular filters on waterways“ /MAK/

27 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

 Code of practice “Use of cement-bonded and bituminous materials for grouting armourstones on waterways“ /MAV/

 Recommendations for the use of lining systems on the beds and banks of waterways/EAO/

The following sections 8.2 and 8.3 give additional guidance on issuing invitations to tender and on the execution of the works.

In addition, it must be explicitly stated which parts of the above codes of practice would have to be complied with under the contract for execution of the works.

8.2 Invitations to tender

8.2.1 General

The points stated in section 8.2 must be included in the contract documents at the appropriate places.

In additional to the general specifications, compliance with the technical contract conditions set out in /ZTV-W LB 210/ must be stipulated in the contract for execution of the works.

The properties of the materials must be specified by the Client. The requirements must be specified in the invitation to tender in accordance with the guidance given in /ZTV W LB 210; MAK; MAV; MAG/.

The methods used to install the required materials must ensure that the correct quantity per unit area is placed. It is recommended that documentation relating to the installation methods and equipment, especially in the case of installation under water, be requested when a bid is submitted.

All services relating to quality control and the inspection of the construction work (cf. 8.4) must be included in the standard price unless stated separately in the bill of quantities.

Any connections to structures that need to be executed must be described in detail and, if necessary, the required drawings must be supplied.

The permitted ranges of tolerances for the subgrade must be stated.

It must be specified in the invitation to tender whether bidders are required to provide documentation on

 the type tests for construction products and methods and

 the manufacturers’ declarations of conformity and factory production control (FPC) certificates for construction products on submission of their tender.

Such documentation must always be requested for the materials and methods listed in Table 8.2.1-1.

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Table 8.2.1-1: Documentation to be provided on submission of a tender

Declaration of conformity Type and factory production testing control (FPC) certificate Geotextiles and geotextile-related products X X (EN 13253)

Armourstones (EN 13383) X

Geosynthetic barriers (EN 13362) X X

Materials Permanently flexible lining materials with X clay and hydraulic binders Cementitious and bituminous grouting X materials

Grouting methods X

Methods of installing sealing materials and

Methods Methods X impervious lining systems

The requirements for construction products and methods must be specified clearly and in detail as any bids not including the required documentation stated in Table 8.2.1-1 will automatically be excluded from the tendering procedure.

8.2.2 Armour layer

The following points must be taken into account, as appropriate:

 specification of the required mean stone weight, G50, stated in Table 5.2.1-1 or the required mean

stone size, D50, for riprap armour layers with the appropriate density

 the requirements for contract documents stated in /MAV/ for partially or fully grouted armour layers

In addition to factory production control and the quality checks performed by the Client (see section 8.4) it is recommended that the Contractor be required to submit additional proof of compliance with the requirements for armourstones set out in /DIN EN 13383/ and /TLW/. This requirement should be included as an additional item in the invitation to tender. The tests must be performed on the armourstones as delivered to the construction site by a testing institute accredited in accordance with /RAP Waba/. It is recommended that one test be performed for every 10,000 m2 of the revetment.

The Contractor‘s first quality control test must be performed on the first delivery of armourstones.

The procedure for determining the mean thickness of the installed armour layer must be specified (measurement programme, measuring method and method of evaluating the measurement programme). The

29 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

measurement profiles must be specified by the Client. The measurements shall be recorded in a test report that must be submitted to the Client (see also 8.4.2).

Checking and levelling of the armourstone layer should be specified in the contract if connections to adjacent structures are required.

If topsoil is placed on the armour layer it must be checked that it contains no plant root material that could damage the armour layer or subsequently hinder maintenance work. Problems may arise, for example, if black locust or Japanese knotweed is introduced unintentionally. The plants concerned can even grow from small pieces of root material. The origin of the topsoil to be installed and the types of vegetation at the location from which the soil is taken must be checked.

8.2.3 Underlayers

Underlayers, if required, must be appropriate for the profile.

Any material installed beneath permeable revetments must be filter-stable (see /MAK/) and more permeable than the in-situ soil. Single underlayers may comprise either sand and gravel or stone chippings and crushed rock.

The permeability of underlayers installed beneath impermeable revetments must not exceed that of the in-situ soil.

8.2.4 Minimum requirements for secondary tenders

Secondary tenders are only permitted if they satisfy the minimum requirements set out in the contract documents. The minimum requirements for slope and bottom protection systems and the conditions under which they apply must be clearly described in the specification of works for the Contractor.

The thickness of the armour layer set out in the bill of quantities only applies in conjunction with the specified minimum density, the specified size class of the armourstones, the type of filter and the specified method of measurement.

If changes to the revetment are proposed in secondary tenders (e.g. in the thickness of the armour layer, size class, density, type of filter or impervious lining) it must be verified that the modified revetment would satisfy the minimum requirements. The verifications must be based on the hydraulic actions assumed in the revetment design described in the invitation to tender. The hydraulic actions of relevance to the standard methods of construction are specified in section 3.

If a secondary tender is submitted, the bidder must provide, as a minimum, verification of the following in the bidding documents:

 stability of the revetment in accordance with /GBB/ if the selected method of construction differs from the standard methods of construction specified in /MAR/

 erosion resistance of the armour layer, e.g. by verification of the required D50–value specified in /GBB/ or /MAR/

 proof of compliance with the minimum thicknesses specified in section 5.2 or Annex 5.2.1-3

 density and size class of the armourstones, with a minimum value of D50 or G50

30 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

 void ratio of the armourstone layer, planned type of filter and its characteristics (thickness on installation, density)

 verification of the overall stability in accordance with DIN 4084 (if relevant)

Any changes in the relevant quantities and dimensions must be stated.

8.3 Execution of the works

In addition to the requirements stated in section 8.2, points that need to be considered during the execution of the works are set out below.

Accompanying commercial documents and the CE-marking as specified in /DIN EN 13383, DIN 13253 and DIN 13362/ must be submitted prior to execution of the works and the values stated in them must comply with the invitation to tender.

The Client’s first quality check shall be performed on the first delivery of armourstones.

The surfaces of the subgrade (rough subgrade, lining, filter, etc.) must be free of any foreign material. Erosion channels or holes in the rough subgrade must be eliminated by installing an underlayer, if appropriate.

The materials must be prepared and mixed in such a way that their characteristics and composition comply with those verified in the suitability test and they do not contain any harmful impurities.

Compliance of the finished layer of stones with the requirements must be verified by suitable methods (e.g. sounding in sufficiently closely spaced profiles). The profiles should, where possible, correspond to those used for measuring the depth of the unprotected bottom of the waterway.

Mechanical loading of the finished revetment or its layers by construction machinery is only permitted if it is verified on the construction site that such loads will not cause any damage.

Bubbles of mud may occur beneath geotextiles in the case of fine-grained soils and impervious linings and the appropriate checks of the finished revetment must be conducted by divers. If mud bubbles are detected, their relevance for the works must be assessed by consulting a geotechnical expert familiar with such matters and, if necessary, measures to eliminate such bubbles and prevent any further occurrence thereof must be undertaken.

Impervious linings and filter layers that are not resistant to erosion and anchor cast must be protected by installing the armour layer immediately (or within 48 h at the latest /ZTV W LB 210/). If this deadline is not observed during construction, the Contractor must state the length of time that elapsed before the armour layer was installed and the means used to check the stability or strength of the lining material. Such de- viations from the requirements are only permitted after prior approval by the Client.

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8.4 Quality assurance

8.4.1 General

Compliance with the requirements for the production, characteristics and processing of construction materials, construction material systems and components as well as for the finished works is ensured by quality assurance procedures comprising the quality control of the construction materials and the execution of the works.

The construction materials used for slope and bottom protection systems on waterways must be as specified

 solely in harmonized European Standards (for armourstones, aggregates),

 in harmonized European Standards in conjunction with additional specifications for waterways engineering (geotextiles) and

 in national rules for waterways engineering (grout, clay, permanently flexible lining materials with clay and cement).

Products in accordance with harmonized European Standards (such as armourstones and aggregates) must be supplied with the accompanying commercial documents, the CE-marking and the declaration of conformity. The CE-marking may only be affixed to the construction products used for the applications covered by this Code of Practice if the manufacturer has drawn up a declaration of conformity stating that the product conforms to the relevant harmonized standard and if the factory production control (FPC) certificate specified in the relevant standard has been issued.

Compliance of the properties of geotextiles with harmonized European Standards is confirmed by the CE- marking. In addition, compliance with the supplementary requirements specific to waterways engineering is certified by a type testing certificate issued by the Federal Waterways Engineering and Research Insti- tute (BAW).

In the case of grout, clay and permanently flexible lining materials with clay and cement, verification of the suitability in principle of the materials and installation methods is confirmed by a type testing certificate issued by the Federal Waterways Engineering and Research Institute. The suitability of construction materials and installation methods for a particular site must be verified at the beginning of the execution of the works by means of a suitability test performed by the Contractor.

A summary of the technical rules of relevance to the construction of navigable waterways and the associated fields of application is given in the List of Technical Rules for Waterways Engineering /TR-W/ drawn up for the Federal Waterways and Shipping Administration (WSV) by the Federal Ministry for Transport, Building and Urban Affairs.

The Contractor bears the responsibility for executing the works as specified in the contract. He must ver- ify that the works have been correctly executed by conducting the quality control procedures for construction materials and procedures set out in /ZTV-W 210/. In addition to the FPC during the production of the materials and the Contractor’s quality control procedures, the Client should perform quality checks on the construction materials and during execution of the works. The type and scope of the quality checks must be set out as far as possible in the specification of the works so that the Contractor is able to make the

32 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

necessary preparations to deal with any interruptions in the construction work and make available any equipment that may be required.

Quality checks for works executed under water should be carried out by divers on the Client`s behalf and samples should be taken if necessary.

8.4.2 Depth measurements for quality assurance

It is stipulated in /ZTV-W 210/ that the thickness of the finished revetment must be verified. This is usually done by means of depth measurements performed with a staff. In addition, depth measurements taken over swathes of the waterway bed are recommended to check the quality of the works.

The results of the depth measurements must be recorded and stored to enable them to be compared with the regular measurements conducted as part of safety inspections and so that any damage can be repaired during maintenance work.

If acceptance measurements are conducted by means of a staff, attention must be paid to the design of the tip. The thicknesses of the armour layers specified in section 5.2 apply to depth measurements based on the level of the highest points of the armourstones, e.g. depth measurements performed with a frame or a staff with a large disc-shaped foot with a diameter of around 30 cm or higher. Measurements performed with spherical foot staffs are also common (with foot diameters of 9 cm for CP90/250, 12 cm for

LMB5/40 and 15 cm for LMB10/60, cf. guidance in /STLK 210/); in this case the depth is measured in the gaps between the armourstones instead of at their highest points. The layer thicknesses and void ratios obtained by depth measurements performed with a spherical foot staff are lower than those obtained with a conventional staff (cf. section 5.1). If the spherical foot diameters stated above are used, the measured upper edge of the revetment will be around 3 to 5 cm lower than that measured at the highest points of the armourstones.

Precise methods of measurement must be used to perform depth measurements over swathes of a revetment. Measurements of the level and depth of any point on the bottom of the waterway must be accu- rate to within a maximum of +/-10 cm, taking account of all factors influenced by the survey vessel and its movements.

The grid selected for the digital model of the bed of the waterway should be such that the highest possible resolution of the structures on the bottom and on the slopes is achieved. The resolution depends on the measuring method (depth measurements taken from a boom or by multibeam echo sounding), the ship speed, signal frequency, footprint and number or spacing of the sensors (transducers). A grid with a maximum size of 0.30 x 0.30 m2 is recommended.

8.5 As-built documents

As-built documents in which all of the most important information is recorded must be prepared for the finished slope and bottom protection system. They include documentation of the following:

 the location of the works

 the type of ground in accordance with /DIN EN ISO 14688/ and /DIN 18196/ (soil investigation report)

33 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

 the method used to construct the slope or bottom protection system, with a detailed description of the installation method, toe design and connections to adjacent structures

 in the case of secondary tenders, verification of compliance with the minimum requirements

 in the case of flexible linings comprising soils and permanently flexible lining materials with hydraulic binders, the mechanical soil parameters on installation, the type and quantity of any addi- tives and the source of the materials

 the installation plan for geosynthetic clay liners (type, product information)

 the type of filter (geotextile: type, product information; granular filter: grading)

 the armourstone size class and thickness of the installed armourstone layer, type of stone, source of the stone (quarry or, for manufactured stones, the producer), particle size or mass distribution, densities, CE–marking and conformity certificates

 for fully or partially grouted armour layers, the type and quantity of grout used (l/m2), installation method, installation plan with all relevant data (losses due to erosion, flow diameter of the grout, quantities used)

 daily site records, including any details of particular significance (e.g. any defects detected during quality checks or reservations during acceptance, divers’ reports, records of depth measurements)

 acceptance depth measurements of the slopes and the bottom

8.6 Guidance on maintenance

Riprap armour layer can be placed or restored to their original condition under water without the use of specialized equipment.

Contracts for the installation and repair of grouted armour layers under water must be placed with special- ist companies employing procedures which have passed the basic test specified in /MAV/ or working as directed by the Federal Waterways and Shipping Administration (WSV).

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9 Literature

/BinSchStrO/ Bundesministerium für Verkehr, Bau und Stadtentwicklung Binnenschifffahrtsstraßen-Ordnung, BinSchStrO Wasser- und Schifffahrtsverwaltung des Bundes, 2005

/DIN EN 13253/ Deutsches Institut für Normung e. V. (Hrsg.) Geotextilien und geotextilverwandte Produkte (EN 13253, Geotextiles and geotextile-related products) Beuth-Verlag, Berlin

/DIN EN 13362/ Deutsches Institut für Normung e. V. (Hrsg.) Geosynthetische Dichtungsbahnen (EN 13362, Geosynthetic barriers) Beuth-Verlag, Berlin

/DIN EN 13383/ Deutsches Institut für Normung e. V. (Hrsg.) Wasserbausteine Teil 1 und Teil 2 (EN 13383, Armourstone, Parts 1 and 2) Beuth-Verlag, Berlin

/DIN EN ISO 14688/ Deutsches Institut für Normung e. V. (Hrsg.) Geotechnische Erkundung und Untersuchung – Benennung, Beschreibung und Klassifizierung von Boden Teil 1 und Teil 2 (EN ISO 14688, Geotechnical investigation and testing – identification and classification of soil – Parts 1 and 2) Beuth-Verlag, Berlin

/DIN 18196/ Deutsches Institut für Normung e. V. (Hrsg.) Erd- und Grundbau – Bodenklassifikation für bautechnische Zwecke Beuth-Verlag, Berlin

/DIN 52101/ Deutsches Institut für Normung e. V. (Hrsg.) Prüfverfahren für Gesteinskörnungen – Probenahme Beuth-Verlag, Berlin

/EAAW/ Deutsche Gesellschaft für Geotechnik e.V. Empfehlungen für die Ausführung von Asphaltarbeiten im Wasserbau, EAAW DGGT, Entwurf, Ausgabe 2008

35 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

/EAO/ Bundesanstalt für Wasserbau Empfehlungen zur Anwendung von Oberflächendichtungen an Sohle und Böschung von Wasserstraßen, Mitteilungsblatt Nr. 85 English version: Recommendations for the Use of Lining Systems on Bed and Banks of Wa- terways, Bulletin No. 85 – English translation Eigenverlag, Karlsruhe 2002

/GBB/ Bundesanstalt für Wasserbau Grundlagen zur Bemessung von Böschungs- und Sohlensicherungen an Binnenwasserstraßen, Mitteilungsblatt Nr. 87 English version: Principles for the Design of Bank and Bottom Protection for Inland Water- ways, Bulletin No. 88 Eigenverlag, Karlsruhe 2004

/Kayser 2005/ Bundesanstalt für Wasserbau BAW-Brief Nr. 2/05, Zur Handhabung der neuen Norm DIN EN 13383 für Wasserbausteine und deren Umsetzung in einer Steinbemessung’ Eigenverlag, Karlsruhe 2005

/MAG/ Bundesanstalt für Wasserbau Merkblatt Anwendung von geotextilen Filtern an Wasserstraßen (MAG) English version: Code of Practice “Use of Geotextile Filters on Waterways” (MAG) Eigenverlag, Karlsruhe 1993

/MAK/ Bundesanstalt für Wasserbau Merkblatt Anwendung von Kornfiltern an Wasserstraßen (MAK)‚ Eigenverlag, Karlsruhe 1989

/MAV/ Bundesanstalt für Wasserbau Merkblatt Anwendung von hydraulisch- und bitumengebundenen Stoffen zum Verguss von Wasserbausteinen an Wasserstrassen (MAV) Eigenverlag, Karlsruhe 2007

/MSD/ Bundesanstalt für Wasserbau Merkblatt Standsicherheit von Dämmen an Bundeswasserstraßen (MSD) Eigenverlag, Karlsruhe 2005

/RAP Waba/ Bundesanstalt für Wasserbau Richtlinie für die Anerkennung von Prüfstellen für Wasserbausteine im Verkehrswasserbau Eigenverlag, Karlsruhe 2007

36 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008

/RiReS/ Bundesministerium für Verkehr, Bau und Stadtentwicklung Richtlinien für Regelquerschnitte von Binnenschifffahrtskanälen BMVBS, Intranet der WSV

/RPW/ Bundesanstalt für Wasserbau Richtlinien für die Prüfung von mineralischen Weichdichtungen im Verkehrswasserbau Eigenverlag, Karlsruhe 2006

/STLK 207/ Bundesministerium für Verkehr, Bau und Stadtentwicklung Standardleistungskatalog für den Wasserbau, Landschaftsbau (Leistungs- bereich 207) Internetseite der BAW

/STLK 210/ Bundesministerium für Verkehr, Bau und Stadtentwicklung Standardleistungskatalog für den Wasserbau, Böschungs- und Sohlensicherungen (Leistungsbereich 210) Internetseite der BAW

/TLG/ Bundesministerium für Verkehr, Bau und Stadtentwicklung Technische Lieferbedingungen für Geotextilien und geotextilverwandte Produkte an Wasserstraßen BMVBS, Intranet der WSV

/TLW/ Bundesministerium für Verkehr, Bau und Stadtentwicklung Technische Lieferbedingungen für Wasserbausteine BMVBS, Intranet der WSV

/TR-W/ Bundesministerium für Verkehr, Bau und Stadtentwicklung Verzeichnis der wesentlichen Technischen Regelwerke – Wasserstraßen – BMVBS, Intranet der WSV

/ZTV-W 210/ Bundesministerium für Verkehr, Bau und Stadtentwicklung Zusätzliche Technische Vertragsbedingungen – Wasserbau für Böschungs- und Sohlensicherungen (Leistungsbereich 210) Internetseite der BAW

37 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008 – Annex 3.1

Annexes

Annex 3.1: Principles of hydraulic design in accordance with /GBB/

Symbol Item Equation in Value /GBB/

LH Development length of the (5-18) Factor fEL = 0.8 boundary layer of the ship:

LH = fEL L

Aw Secondary wave height coeffi- (5-47) 0.25; 0.35 for push-tow units cient (5-43) 1) CH Calculation of drawdown at the (5-29) full: 1.3; empty: 1.5 except : stern Europe ships, full: 1.35 at T/h = 0.625 Very large self-propelled barges, empty: 1.47 at T/h = 0.45 C Drawdown time (5-37) Self-propelled barges (including very large vessels): 1.7 Europe ships/push-tow units: 1.3

 Coefficient for considering the (5-42) = 0.9 wave-generating length of a ship

LPris Length of prismatic cross- (5-40) Self-propelled barges (including very

section: LPris = fL,pris L large vessels), Europe ships:

fL,pris = 0.8

Push-tow units: fL,pris = 0.9

fB Factor of the influence width (5-8),(5-7) fB = 3

Kss Equivalent sand roughness of the (5-18) Kss = 0.0003m

ship’s hull Europe ships: Kss = 0.0005m Factor for Calculation of bow wave (5-28) Factor 1.1 drawdown at the bow

B´B, B*B Coefficient for the frequency of (6-3),(6-4), Certain degree of maintenance required,

recurrence, B*B, (6-5) i.e. unconservative design

stability coefficient, B´B B´B = 2.3; B*B= 3.0 SF Shape factor, stone sizing, con- (6-2) SF = 0.65

version of Dn to D

 Shape factor, conversion of Dn to (6-15)  = 1.8

stone length DTLW (L) explicit

38 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008 – Annex 3.1

Symbol Item Equation in Value /GBB/

y Distance between the ship’s axis Figure 5.14 T-profile RT-profile 2) and the axis of the canal Europe ships: Europe ships: 11.75m 9.86m Self-propelled Self-propelled barges, push-tow barges, push-tow units: 10.78 m units: 8.86 m

Very large self- Very large self- propelled propelled barges: 10.5 m barges: 8.61 m

n Void ratio of the armour layer (7-2) 50 %

g Acceleration due to gravity g = 9.81 m/s²

o ’D Angle of internal friction of the ’D, mechanical = ’D,hydraulic = 55 dumped stones or other armour layer material

Note: Push-tow units are assumed to be rigid vessels in the calculations. 1) Linear interpolation between CH = 1.3 and CH = 1.5 2) Eccentricity of the main axis of the profile minus 1.5 m owing to the different behaviour of ships in RT-profiles

39 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008 – Annex 3.2.1

Annex 3.2.1: Hydraulic loads at 97 % vkrit for standard T-profiles

Regel-Trapez-Profil für 97 % v_krit

ES GMS SV üGMS leer voll leer voll leer voll leer voll

vkrit [m/s] 3.63 3.04 3.32 2.66 3.27 2.61 3.13 2.58

hu,Bug [m] 0.12 0.36 0.12 0.36 0.08 0.33 0.12 0.35

hu,Heck [m] 0.40 0.46 0.43 0.47 0.44 0.47 0.45 0.47

vrück,u,Bug [m/s] 0.30 1.03 0.34 1.16 0.23 1.08 0.35 1.15

vrück,u,Heck [m/s] 1.30 1.48 1.49 1.63 1.53 1.67 1.58 1.68

umax [m/s] 2.10 2.53 2.46 2.53 2.51 2.52 2.56 2.50

Hsek,q / 2 [m] 0.15 0.10 0.13 0.08 0.18 0.11 0.12 0.08

Hu,Bug [m] 0.20 0.61 0.20 0.60 0.13 0.54 0.19 0.57

Hu,Heck [m] 0.93 0.95 0.97 0.91 0.98 0.91 0.98 0.91 hydraulische Größen

ta,B [s] 3.8 4.5 5.9 7.4 4.6 5.8 6.5 7.8

ta,H [s] 23.1 27.6 33.3 41.5 57.2 71.5 42.1 51.0

vza,B [m/s] 0.05 0.14 0.03 0.08 0.03 0.09 0.03 0.07

vza,H [m/s] 0.04 0.03 0.03 0.02 0.01 0.01 0.02 0.02

für Hinweis: 3 Bei Übereinstimmung können bis zu S = 2650 [kg/m ] Max nur ES und GMS drei Markierungen auftreten !! Min bei t a

Max ohne üGMS

Min bei ta

Max aller Schiffe

Min bei ta

Symbole:

vkrit kritische Schiffsgeschwindigkeit

h u,Bug / hu,Heck mittlere Wasserspiegelabsenkung am Ufer am Bug/Heck

vrück,u,Bug / vrück,u,Heck Rückströmungsgeschwindigkeit am Bug/Heck

umax Geschwindigkeit der Wiederauffüllungsströmung

Hsek,q Höhe der Sekundärquerwelle

Hu,Bug / Hu,Heck Maximalwert der Wellenhöhe am schiffsnäheren Ufer bei exzentrischer Fahrt am Bug/Heck

ta,B / ta,H Absunkzeit am Bug/Heck vza,B / vza,H Absunkgeschwindigkeit am Bug/Heck

40 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008 – Annex 3.2.2

Annex 3.2.2: Hydraulic loads at 97 % vkrit for standard RT-profiles

Standard rectangular trapezoidal profile for 97 % v_krit

Large self- Very large self- Europe ships Push-tow units propelled propelled (ES) (SV) barges (GMS) barges (üGMS)

empty full empty full empty full empty full

vkrit [m/s] 3.81 3.18 3.48 2.78 3.42 2.73 3.27 2.69

hu,Bug [m] 0.13 0.40 0.13 0.40 0.09 0.36 0.13 0.38

hu,Heck [m] 0.44 0.50 0.48 0.51 0.48 0.52 0.49 0.52

vrück,u,Bug [m/s] 0.32 1.08 0.35 1.21 0.24 1.13 0.37 1.20

vrück,u,Heck [m/s] 1.36 1.55 1.56 1.71 1.60 1.74 1.65 1.75

umax [m/s] 2.02 2.55 2.45 2.57 2.51 2.57 2.57 2.56

Hsek,q / 2 [m] 0.15 0.11 0.14 0.09 0.19 0.12 0.12 0.08

Hu,Bug [m] 0.21 0.64 0.20 0.62 0.14 0.56 0.20 0.59

Hu,Heck [m] 0.97 0.98 1.01 0.94 1.02 0.95 1.01 0.94 Hydraulic parameters

ta,B [s] 4.0 4.7 6.2 7.7 4.8 6.0 6.7 8.1

ta,H [s] 22.4 26.8 32.3 40.4 55.0 69.0 40.7 49.5

vza,B [m/s] 0.05 0.13 0.03 0.08 0.03 0.09 0.03 0.07

vza,H [m/s] 0.04 0.04 0.03 0.02 0.02 0.01 0.02 0.02

for N.B.: Up to three identical values may be marked !! 3 S = 2650 [kg/m ] Maximum, Europe ships and self-propelled barges only

Mininum at t a

Maximum, without very large self-propelled barges

Mininum at t a

Maximum for all ships

Minimun at ta

Symbols:

vkrit Critical ship speed

h u,Bug / hu,Heck Average drawdown at bow/stern at the bank

vrück,u,Bug / vrück,u,Heck Return flow velocity at bow/stern

umax Velocity of slope supply flow

Hsek,q Height of secondary transversal waves

Hu,Bug / Hu,Heck Maximum height of bow/stern wave at the bank for eccentric sailing

ta,B / ta,H Drawdown time at bow/stern

vza,B / vza,H Drawdown rate at bow/stern

41 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008 – Annex 4.1-1

Annex 4.1-1: Guidance on how to determine the mean stone size, D50, or the mean

stone weight, G50

The design stone size, D50, or stone weight, G50, must be specified in the invitation to tender. Quality checks should be carried out on 100 stones to check compliance with the design value. The stones must be sampled from the armourstones as delivered as specified in /DIN EN 13383-2/ and /DIN 52101/.

G50 can be determined with a sufficient degree of accuracy from the semilogarithmic cumulative curve of the weighed stones.

It is not possible to calculate D50 exactly as the grading is determined in stages by means of separate sieves with square perforations. The following method is therefore proposed for the calculation of D50.

The size distribution is determined by using each of the standard sieves available for the range of each size class (e.g. 45/63/90/125/180/250/360 mm for CP90/250). The percentage, P, in %, passing the sieve closest to 50 % (lower, Pu; higher, Po) and the corresponding sieve diameters, Do and Du , are used to determine D50 by means of logarithmic-linear interpolation between the two pairs of values, Pu/Du and

Po/Do (see figure).

Figure: Determination of D50 by interpolation

D50 is determined by log-linear interpolation as follows:

P50  D  u DD  o  PP uo  u50    Du 

42 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008 – Annex 4.1-2

Annex 4.1-2: Cumulative curves for armourstones - classes LMB10/60, LMB5/40, CP90/250

Typical range of variation: Range in which the greater part of the cumulative curve generally lies (this is purely informative and is not a requirement).

43 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008 – Annex 5.2.1-2

Annex 5.2.1-1: Permeable armour layers comprising riprap –

Recommended thicknesses, dD, of armour layers for slope and bottom protection systems

a.) b.) Recommended armour layer thicknesses , dD, for soil types B1, B2, B5, flexible linings

Recommended armour layer thicknesses, dD [m] Size class Density ρS with embedded toe (embedment depth: 1.50 m) [kg/m3] Slope Bottom

Geotextile Granular filter c.) Geotextile Granular filter c.)

CP90/250 3600 0.50 0.50 0.60 0.50 2650 0.60 0.60 0.60 0.60 LMB5/40 3000 0.55 0.55 0.60 0.55 3600 0.55 0.55 0.60 0.55 2300 0.70 0.70 0.70 0.70 LMB10/60 2650 0.65 0.65 0.65 0.65 3000 0.65 0.65 0.65 0.65 3600 0.60 0.60 0.60 0.60

a.) Recommended armour layer thicknesses , dD, for soil type B3

Recommended armour layer thicknesses dD [m] Size class Density ρS with embedded toe (embedment depth: 1.50 m) [kg/m3] Slope Bottom

Geotextile Granular filter c.) Geotextile Granular filter c.)

CP90/250 3600 0.50 0.50 0.60 0.50 2650 0.70 0.60 0.60 0.60 LMB5/40 3000 0.60 0.55 0.60 0.55 3600 0.55 0.55 0.60 0.55 2300 0.85 0.70 0.70 0.70 LMB10/60 2650 0.70 0.65 0.65 0.65 3000 0.65 0.65 0.65 0.65 3600 0.60 0.60 0.60 0.60

a.) Recommended armour layer thicknesses , dD, for soil type B4

Recommended armour layer thicknesses dD [m] Size class Density ρS with embedded toe (embedment depth: 1.50 m) [kg/m3] Slope Bottom

Geotextile Granular filter c.) Geotextile Granular filter c.)

CP90/250 3600 0.60 0.50 0.60 0.50 2650 0.80 0.60 0.60 0.60 LMB5/40 3000 0.70 0.55 0.60 0.55 3600 0.60 0.55 0.60 0.55 2300 0.95 0.70 0.70 0.70 LMB10/60 2650 0.80 0.65 0.65 0.65 3000 0.70 0.65 0.65 0.65 3600 0.60 0.60 0.60 0.60

44 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008 – Annex 5.2.1-1

Explanatory notes: a.) The recommended armour layer thicknesses apply to trapezoidal profiles and rectangular-trapezoidal profiles as defined in section 3.3 and take the following factors into consideration:

1.) Minimum thicknesses (see Annex 5.2.1-3) to take account of the following:

ship collision (as per GBB-eq. 6-20) anchor cast (as per GBB-eq. 6-19) UV-protection for geotextiles (as per GBB-eq. 6-22) granular filters (as per GBB-eq. 6-21)

uniformity of the armourstone layer (as per GBB-eq. 6-17) 1/2 min dD = 1.5 * Dn50 (U) with U = D60/D10 to ensure stability of the armourstone layer (see section 4 of the article pub-

lished in BAW-Brief 2-2005)

2.) Thickness of the armour layer (see Annex 5.2.1-2) required by the

geotechnical design

The verification required in each case is indicated in colour. The armour layer thicknesses calculated for trapezoidal and rectangular trapezoidal profiles in accordance with Annex 5.2.1-2 have been averaged.

The final values obtained for the armour layer thickness have been rounded to the nearest 5/100 [m]. b.) The recommended thicknesses of armour layers placed on flexible linings only correspond to the stated minimum thicknesses if the groundwater level is lower than the water level in the canal when lowered by shipping. The safety against uplift must otherwise be verified (see Annex 5.6.2-1). c.) The granular filter used for the recommended armour layer thickness may be a double mineral filter (thickness: 2 x 20 cm) or a mixed granular filter (thickness: 30 cm) as specified in MAK.

45 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008 – Annex 5.2.1-2

Annex 5.2.1-2: Permeable armour layers comprising riprap – Documentation of the armour layer thicknesses,

dD, calculated for slopes (with a geotextile)

Armour layer thicknesses, dD, calculated for a trapezoidal profile

1.00 Soil type 4 0.91 0.90 Soil type 3 0.80 0.81 0.79 Soil type 2 [m]

D Soil type 1 0.70 0.69 0.70 CP90/250 0.60 0.61 0.59 0.55 LMB5/40 0.50 0.51 LMB10/60 0.46 0.40 0.40 0.32 Trapezoidal profile 0.30 0.29 0.24 Riprap

Armour layer thickness d 0.20 0.20 0.16 0.10

0.00 2200 2400 2600 2800 3000 3200 3400 3600 3800

Density of the stones  s [kg/m³]

Armour layer thicknesses, dD, calculated for a rectangular-trapezoidal profile

1.00 0.94 Soil type 4 0.90 Soil type 3 0.84 0.80 0.81 Soil type 2 [m] D 0.70 0.72 0.72 Soil type 1 0.63 CP90/250 0.60 0.60 0.56 LMB5/40 0.53 0.50 0.47 LMB10/60 0.40 0.41 0.33 Rectangular- 0.30 0.30 0.25 trapezoidal profile 0.21 Armourlayer thickness d 0.20 0.17 Riprap 0.10

0.00 2200 2400 2600 2800 3000 3200 3400 3600 3800

Density of the stones  s [kg/m³]

Explanatory notes:

The thicknesses of armour layers on slopes for soil types 1 to 4 and the minimum thicknesses for stone size classes CP and LMB in accordance with Annex 5.2.1-3 (broken lines) are shown. A geotextile and an embedded toe (embedment depth: 1.50 m) have been taken into account. The minimum thicknesses always apply in the case of soil type B5. In the case of armour layers placed on flexible linings, the minimum thicknesses only apply if the groundwater level is lower than the water level in the canal when lowered by shipping. The safety against uplift must otherwise be verified (see Annex 5.6.2-1).

46 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008 – Annex 5.2.1-3

Annex 5.2.1-3: Permeable armour layers comprising riprap – Calculated minimum thicknesses

Calculated minimum thicknesses, dD Minimum thickness of the Minimum thickness of the layer Density Size class D50 grain size layer at the bottom on the slopes placed on a placed on a placed on a placed on a [kg/m³] [-] [m] granular filter geotextile granular filter geotextile [m] [m] [m] [m]

CP90/250 0.150 0.50 0.60 0.50 0.50

2300 LMB5/40 0.211 0.62 0.62 0.62 0.62

LMB10/60 0.254 0.71 0.71 0.71 0.71

CP90/250 0.150 0.50 0.60 0.50 0.50

2650 LMB5/40 0.202 0.59 0.60 0.59 0.59

LMB10/60 0.242 0.67 0.67 0.67 0.67

CP90/250 0.150 0.50 0.60 0.50 0.50

3000 LMB5/40 0.194 0.56 0.60 0.56 0.56

LMB10/60 0.232 0.65 0.65 0.65 0.65

CP90/250 0.150 0.50 0.60 0.50 0.50

3600 LMB5/40 0.176 0.53 0.60 0.53 0.53

LMB10/60 0.219 0.61 0.61 0.61 0.61

Explanatory notes The values shown in the table take the following into account: ship collision: GBB-eq. (6-20) anchor cast: GBB-eq. (6-19) UV-protection of geotextile filters (slopes only): GBB-eq. (6-22) granular filters: GBB-eq. (6-21)

the coefficient of uniformity: GBB-eq. (6-17) 1/2 min dD = 1.5 * Dn50 (U) with U = D60/D10 to ensure the stability of the armour layer, see BAW-Brief 2/2005 Formeln wie auf S. 93 links oben

The minimum thicknesses shown are not dependent on the cross-section of the waterway (trapezoidal or rectangular-trapezoidal profile).

47 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008 – Annex 5.2.2-1

Annex 5.2.2-1: Permeable armour layers comprising partially grouted armourstones – Recommended

thicknesses,dD, armourlayers for slope and bottom protection systems (with a geotextile)

Recommended armour layer thicknesses, dD

Recommended armour layer thicknesses, dD [m] Size Density with embedded toe (embedment depth: 1.50 m)

class ρS Soil type B5/ Soil type B1 Soil type B2 Soil type B3 Soil type B4 flexible lining [kg/m3] 2300 0.40 0.40 0.45 0.70 0.40 CP90/250 2650 0.40 0.40 0.40 0.55 0.40 or 3000 0.40 0.40 0.40 0.45 0.40 LMB5/40 3600 0.40 0.40 0.40 0.40 0.40

Explanatory notes:

The recommended armour layer thicknesses apply to trapezoidal profiles and rectangular-trapezoidal profiles as defined in section 3.3 if a geotextile is used. The armour layer thicknesses calculated in accordance with Annex 5.2.2-2 for trapezoidal and rectangular-trapezoidal profiles have been averaged. The final values obtained for the armour layer thicknesses, taking the minimum thickness into account, have been rounded to the nearest 5/100 [m].

The required armour layer thicknesses obtained by calculation are affected only to a very small degree by the quantity of grout used. The thicknesses recommended in the table therefore apply to all partially grouted armour layers in accordance with section 5.2.2 in trapezoidal and rectangular trapezoidal profiles as defined in section 3.3, irrespective of the quantity of grout used. A grout quantity of 50 l/m² was taken into account in the calculation of the required armour layer weight.

Yellow shading indicates that the minimum thickness applies. The minimum thickness is 40 cm for partially grouted armour layers if stone size classes CP90/250 and LMB5/40 are used, irrespective of the type of filter. If a granular filter is used, the required armour layer thickness may be reduced by the thickness of the filter, but must be not less than the minimum thickness of 40 cm. If a double mineral filter (thickness: 2 x 20 cm) is used, the minimum armour layer thickness specified for partially grouted armour layers must always be complied with, irrespective of the range given in the table.

The recommended thicknesses (minimum thicknesses) of armour layers on flexible linings only apply if the groundwater level is lower than the water level in the canal when lowered by shipping. The safety against uplift must otherwise be verified (see Annex 5.6.2-2).

48 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008 – Annex 5.2.2-2

Annex 5.2.2-2: Permeable armour layers comprising partially grouted armourstones – Documentation of the

armour layer thicknesses, dD, calculated for slopes (with a geotextile)

Armour layer thicknesses, dD, calculated for a trapezoidal profile

0.80 Soil type 4 0.70 Soil type 3 0.66 Soil type 2

[m] 0.60 D Soil type 1 0.52 0.50 Minimum thickness

0.43 0.43 0.40

0.34 0.33 0.30 Trapezoidal profile 0.28 Partially grouted 0.22 0.20

Armour layer thickness d 0.15 0.12 0.10 0.10 0.07

0.00 0.00 0.00 0.00 0.00 2200 2400 2600 2800 3000 3200 3400 3600 3800

Density of the stones  s [kg/m³]

Armour layer thicknesses, dD, calculated for a rectangular-trapezoidal profile

0.80 Soil type 4 0.70 0.71 Soil type 3 Soil type 2

[m] 0.60 D 0.56 Soil type 1 0.50 Minimum thickness 0.48 0.46 0.40 0.38 0.36 0.30 0.31 Rectangular- 0.24 trapezoidal profile 0.20 Partially grouted

Armour layer thickness d 0.16 0.13 0.10 0.10 0.08

0.00 0.00 0.00 0.00 0.00 2200 2400 2600 2800 3000 3200 3400 3600 3800

Density of the stones  s [kg/m³]

Explanatory notes:

The thicknesses calculated for armour layers on slopes for soil types 1 to 4 and the minimum thicknesses for stone size classes CP90/250 and LMB5/40 (broken lines) are shown. A geotextile, an embedded toe (embedment depth: 1.50 m) and a grout quantity of 50 l/m2 have been taken into account in the calculations by way of additional weight. The required armour layer thicknesses obtained by calculation are affected only to a very small degree by the quantity of grout used. The minimum thicknesses always apply in the case of soil type B5. In the case of armour layers placed on flexible linings, the minimum thicknesses only apply if the groundwater level is lower than the water level in the canal when lowered by shipping.The safety against uplift must otherwise be verified (see Annex 5.6.2-2).

49 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008 – Annex 5.2.3

Annex 5.2.3: Impermeable armour layers comprising fully grouted armourstones

placed on a geotextile – Required armour layer thicknesses, dD, against buoyancy

Basis of the calculation:

Safety against uplift a = 1,0

Drawdown za = 0,89 m ( za = Drawdown relevant for Void ratio n = 50% calculating buoyancy)

W = 9,81 kN/m³

V = 22 kN/m³ max. GW   zh )(  BW A WaW    d u hW cos FF d  za hW D n n   )()()1( S W V W h with   d  geotextile)(0 W FF  and S =  S  g

1  Hz  H ,Heckua 2 ,qsek Maximum value of za in accordance with the parameters given in Annexes 3.2.1 and 3.2.2

Slope (inclination 1:3) Bottom

Impermeable armour layer Fully grouted Impermeable armour layer Fully grouted 1.4 1.4 Density  1.3 s 1.3 Density s [m] [m] D 1.2 2300 kg/m³ D 1.2 2300 kg/m³ 1.1 2650 kg/m³ 1.1 2650 kg/m³ 1.0 3000 kg/m³ 1.0 3000 kg/m³ 0.9 3600 kg/m³ 0.9 3600 kg/m³ 0.8 0.8 0.7 0.7 0.6 0.6 Armour layer thickness d thickness layer Armour 0.5 Armour layer thickness d 0.5 0.4 0.4 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8

Difference in water levels hW [m] Difference in water levels hW [m]

Minimum thicknesses of fully grouted armour layers as a function of the size class and density of the stones used:

LMB5/40 LMB10/60

s < 3000 kg/m³ 40 cm 50 cm

s ≥ 3000 kg/m³ 40 cm 40 cm

50 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008 – Annex 5.6.2-1

Annex 5.6.2-1: Permeable armour layers comprising riprap placed on a geotextile,

with an impermeable lining – Required armour layer thicknesses, dD, against buoyancy

Basis of the calculation:

Safety against uplift a = 1,0

Drawdown za = 0,89 m ( za = Drawdown relevant for Void ratio n = 50% calculating buoyancy (see Annex 5.2.3

W = 9,81 kN/m³ for equation))

'Di = 10 kN/m³ (Ton)

max. GW  A  zh )(  WaW      dd BWu h cos  FF Di Di W dD  za hW n S   W )()1( h   dwith FF  geotextile)(0 W  and S =  S  g

Slope (inclination 1:3) Bottom

Clay liner (dDi=20cm) Clay liner (dDi=20cm) 2.0 2.0 Density s Density s 1.8 1.8 [m] [m]

D 2300 kg/m³ D 2300 kg/m³ 1.6 1.6 2650 kg/m³ 2650 kg/m³ 1.4 3000 kg/m³ 1.4 3000 kg/m³ 1.2 3600 kg/m³ 1.2 3600 kg/m³ 1.0 1.0 0.8 0.8 0.6 0.6 Armour layerArmour thickness d layerArmour thickness d 0.4 0.4 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8

Difference in water levels hW [m] Difference in water levels hW [m]

Clay liner (dDI=30cm) Clay liner (dDi=30cm) 2.0 2.0 1.8 1.8 [m] [m] D D 1.6 1.6 1.4 1.4 1.2 1.2 1.0 1.0 0.8 0.8 0.6 0.6 Armour layerArmour thickness d layerArmour thickness d 0.4 0.4 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8

Difference in water levels hW [m] Difference in water levels hW [m]

Geotextile clay liner GCL (dDi=1cm) Geotextile clay liner GCL (dDi=1cm) 2.0 2.0 1.8 1.8 [m] [m] D D 1.6 1.6 1.4 1.4 1.2 1.2 1.0 1.0 0.8 0.8 0.6 0.6 Armour layer thicknessd Armour layer thicknessd 0.4 0.4 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 Difference in water levels hW [m] Difference in water levels hW [m]

The minimum thicknesses specified in Annex 5.2.1-3 must be taken into consideration.

51 BAW Code of Practice: Use of Standard Construction Methods for Bank and Bottom Protection on Inland Waterways, Issue 2008 – Annex 5.6.2-2

Annex 5.6.2-2: Permeable armour layers comprising partially grouted armourstones placed on a geotextile, with an impermeable lining – Required armour

layer thickness, dD, against buoyancy

Basis of the calculation:

Safety against uplift a = 1,0

Drawdown za = 0,89 m ( za = Drawdown relevant for Void ratio n = 50% calculating buoyancy (see Annex 5.2.3

W = 9,81 kN/m³ for equation))

'Di = 10 kN/m³ (Ton)

mV ≥ 0,05 m³/m² (= 50 l/m²) max. GW  = 22 kN/m³ V BW u hW  A  zh )(  WaW   FF    DiDi mdd   Wvv )( cos za hW d  D n   )()1( S W hW  with  dFF  geotextile)(0 

and S =  S  g Slope (inclination 1:3) Bottom

Clay liner (dDi=20cm) Partially grouted Clay liner (dDi=20cm) Partially grouted 2.0 2.0 Density s Density s 1.8 1.8 [m] [m] D 2300 kg/m³ D 2300 kg/m³ 1.6 1.6 2650 kg/m³ 2650 kg/m³ 1.4 3000 kg/m³ 1.4 3000 kg/m³ 1.2 3600 kg/m³ 1.2 3600 kg/m³ 1.0 1.0 0.8 0.8 0.6 0.6 Armour layer thickness d thickness layer Armour Armour layer thickness d thickness layer Armour 0.4 0.4 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8

Difference in water levels hW [m] Difference in water levels hW [m]

Clay liner (dDi=30cm) Partially grouted Clay liner (dDi=30cm) Partially grouted 2.0 2.0 1.8 1.8 [m] [m] D D 1.6 1.6 1.4 1.4 1.2 1.2 1.0 1.0 0.8 0.8 0.6 0.6 Armour layer thickness d thickness layer Armour Armour layer thickness d thickness layer Armour 0.4 0.4 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8

Difference in water levels hW [m] Difference in water levels hW [m]

Geotextile clay liner GCL (d =1cm) Geotextile clay liner GCL (dDi=1cm) Di 2.0 2.0 Partially grouted 1.8 Partially grouted 1.8 [m] [m] D D 1.6 1.6 1.4 1.4 1.2 1.2 1.0 1.0 0.8 0.8 0.6

0.6 d thickness layer Armour Armour layer thickness d thickness layer Armour 0.4 0.4 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 Difference in water levels h [m] Difference in water levels hW [m] W