The scope of the Project Hobyo Fishing Jetty
DOCUMENT CONTROL SHEET Country: Somalia Project Title: Fishing jetty construction in Hobyo Document Title: Scope of the project works Document No.: Revision: 0 Status: Draft Author(s): Reviewed by: Office of Origin: SOCO Issue Date: 25.10.2018
Somalia CO Logistics
[Hobyo Fishing Jetty] [Scope of Works]
1. PREAMBLE
Somalia is one of the most food insecure countries in the world where more than 2.5 million people are now reported to be in crisis. Since the start of the civil war in 1991, the country has suffered from recurrent droughts, conflict, and instability, as well as lack of a functioning central government. The conflict has created a situation of protracted and complex emergency in the process eroding livelihoods, leading to increased vulnerability to economic shocks, malnutrition, and food insecurity.
Somalia, with 3 300 km of coastline facing the Gulf of Aden and the Indian Ocean, has the longest coast in continental Africa, an important feeding ground for many migratory fish species and a narrow but productive coastal shelf. In addition, over 10 000 km2 of the inland water area with two permanent rivers, the Jubba and the Shabele, support an optimistic forecast for future potential in inland fisheries. Therefore fisheries can play an important role to improve food security and support economic development, provided that fisheries management is in place and piracy and illegal, unreported and unregulated and (IUU) fishing are ended. The marine fisheries resources of Somalia have significant potential to contribute to the food and nutrition security, economic growth and the building of livelihoods resilient to threats and crises, not only in Somalia itself but the wider Horn of Africa region. However, despite having the longest coastline in Africa, oceanic waters that are enriched by upwelling and that are consequently much more productive than most oceanic areas of the world.
Hobyo is an ancient port city in Galmudug state in the north-central Mudug region of Somalia. The port was once considered a haven for pirates and one of the most dangerous places in Somalia. However, with the change in fortune in piracy activities, the port is now focused on fishing activities again and serves as an entry point for goods from the Gulf. However, due to continuing security risks, recurrent droughts and inaccessibility, livelihoods in Hobyo have been significantly curtailed, which has resulted in destitution and loss of pastoral livelihoods, particularly among the lower income groups.
2. PROJECT
2.1 INTRODUCTION
WFP (the Employer) has planned an intervention in Hobyo, which consist of installing a fish landing jetty to revive the local fishing industry. To define location and parameters of the jetty WFP has carried out Class 2 hydrographic survey (as per Engineering Manual EM 1110-2-1-1003, Hydrographic Surveying, US Army Corps of Engineers) in Hobyo. Based on the hydrographic survey results the jetty concept (after the presentation approved by the authorities of Galmudug State) and a detailed design were developed.
While working on the concept, various design solutions were considered based on the author’s experience (port engineer – the jetty design author) on other marine-related construction projects in both existing ports (like Mogadishu, Bosasso and Berbera, which have good access to commercial transport) and isolated coastal communities (like Haafun, Garaad, Las Qoray and Maydh). Marine works, by their very nature, are costly; they require specialised equipment and progress is dependent on good weather or calm seasons. In isolated coastal communities like Hobyo, difficulties in road access, lack of natural resources and logistical hurdles have a large impact on the potential types of solutions that may be adopted. The following list summarises these hurdles:
• It is practically impossible to find a local contractor with any experience in marine works, so much so that all such projects normally involve a strong expatriate presence; • The production of marine-grade concrete (using low heat cement and salt-free aggregates) is practically impossible due to the lack of adequate quarries. Opening up a new quarry (following all EIA procedures) is a major operation in itself; • The production of large volumes of marine concrete require good quality drinking water and this places an inordinate strain on the local drinking water supplies as coastal well water generally contains too much salt and cannot be used in concrete;
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• Road access to move in large volumes of materials from distant sources (such as cement in bags from neighboring ports and salt-free aggregate from inland sources) is often an insurmountable obstacle and may be a problem with the site in Hobyo.
By considering the above-listed limitations and project area conditions AN ALL- STEEL PILLED STRUCTURE has been defined as the best option for Hobyo. The advantages of an all-steel piled structure may be summarised as follows:
• An all steel piled jetty does not require concrete; • All steel members may be prefabricated (cut, machined, welded and coated) in a workshop environment and delivered to site ready for installation; • Many of the connections may be bolted, further reducing the on-site fabrication process; • The jetty may be constructed entirely from land; • Construction time is the fastest and less likely to be influenced by weather conditions on site; • The likely method of construction will also have the least impact on the environment.
The main disadvantages of an all steel structure are:
• Any connections that require welding on site need specialised certified welders; • The jetty is subject to corrosion.
The Employer intends to carry out works related to the jetty steel structure fabrication and construction and attracts a qualified, competent, technically equipped companies with proven experience in marine engineering works, equipped with a broad knowledge of existing rules and legal requirements, capable and have the experience to work in Somalia cost. The Contractor shall comply with and give notices required by laws, ordinances, rules, regulations, and lawful orders of public authorities bearing on the performance of the work. It is particularly important that the contractor observes available multilateral commercial diving occupational safety and health administration and guidance.
The Employer proposes two phases of the fishing jetty project implementation: a) Delivery and b) Construction. However, the two-stage implementation of the project should not be considered as a division of the entire contract award. The Contractor will be fully responsible to fulfill all the requirements as specified in the project scope for both phases. The company key staff and technical personnel assigned to the project should be experienced to develop a Site Safety Plan and conduct physical operation within the scope defined below: The company should be knowledgeable in any existing regulations, legal requirements and global best practices in marine engineering/construction work. The contractor is expected to advice on applicable rules and any compensation that may be available.
2.2 PROJECT PHASES
The Contractor shall observe the following task and obligations are fulfilled for each phase:
a) Delivery
Considering a number of risks related to the project implementation, the Employer considers supporting the Company in the process of delivering materials. The Contractor shall ensure the delivery of commodities and hand-over in accordance with details specified below. The Employer, along with the Contractor, shall determine the date and provide the transportation of the goods to the final destination point from Berbera to Hobyo.
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The Contractor Shall:
• Manufacture the steel structure and provide the equipment and electrical fittings as described below under the chapters “Steel Works” and “Equipment and Electrical fittings” • Deliver the jetty steel structure and the equipment and electrical fittings to WFP Berbera warehouse. Terms of the delivery: DAP WFP Berbera warehouse, in Somalia (Incoterms 2010). Consignee details: Gigiri Lane, off UN Crescent, P.O. Box 64902-00620, Nairobi, Kenya • Obtain full insurance of the commodities for the entire leg of delivery from the point of origin up to Hobyo. • Advice the Employer transport mode and a package of the commodities, provide an itemised packing list of the shipment by specifying a description of the commodities, quantities, dimensions, and weights for each line item listed. • Ensure the presence of qualified Company personnel during hand-over processes (inbound and outbound). If goods are not transported in duly locked and sealed containers, supervise commodity handling and ensure steel structure lifting is in accordance to the requirement specified in the article “DELIVERY STORAGE AND PROTECTION” • Ensure availability of sufficient machinery at Hobyo and organise smooth and timely discharge of commodities delivered by the Employer from Berbera. b) Construction
The Contractor shall ensure the jetty assembly and construction in accordance with the design drawings, the scope details specified in the chapter “ASSEMBLY AND CONSTRUCTION” and project timeline submitted to the Employer.
The Contractor shall be solely responsible for and have control over the jetty construction means, methods, techniques, sequences and procedures and for coordination all portions of the Work under the Contract, unless Contract Documents give other specific instructions concerning these matters.
3. STEEL WORKS
3.1 MATERIALS
The steel components shall comprise: • Structural steel sections in Grade S355 G11+M steel to EN 10225 (weldable structural steels for fixed offshore structures); • Steel grating to EN 10025 hot-dipped galvanised to EN ISO 1461; • Stainless steel bolts M20 DIN 933 in Grade A4.
3.2 FABRICATION
Fabrication and execution of all the steelwork shall be in compliance with BS EN 1090.
3.3 FINISHES
All the steel sections whose surface area is to be treated with anti-corrosion paint cycles shall be sand- 1 blasted to ISO 8501-1 (2007) (Swedish Standard SA 2 /2).
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3.4 TOLERANCES
The dimensional tolerances for the prefabricated steel components shall not exceed +/- 2.5 mm.
3.5 DELIVERY STORAGE AND PROTECTION
• All the steel components that have been treated with anti-corrosion paint shall only be lifted at the support points detailed by the fabricator; • In the absence of lifting lugs, the Contractor shall only utilise polyamide straps in order to prevent scratching the paint finish; • Finished elements shall be stored in the horizontal sense only and shall rest on timber battens evenly spaced to prevent rolling and scratching from the uneven ground; • Finished elements shall be transported in stacks with timber spacers between each layer and the next and firmly secured.
3.6 EXAMINATION
Prior to shipping and upon arrival at the destination, the Contractor shall submit a status report on the condition of the anticorrosion paint surface. Any defects and/or scratches sustained during the transport of the elements shall be made good on site prior to installation.
3.7 PLACING AND ERECTION TOLERANCES
The Contractor shall observe the following sequence of construction c) The HEA 300 steel piles shall be mated with the cross beam and suspended over the sockets via scaffold towers to alignment and level tolerance indicated on the drawings; d) Each pile bent thus formed shall be grouted in place as a whole bent; e) The Contractor shall then place the IPE 270 beams as indicated on the drawings followed by the cross bracing and the galvanised grating.
The final tolerances of the jetty cope line shall be as follows:
Alignment: • toward water 5mm over a 10-metre span Level: • +/- 2.5 mm over a 10-metre length
3.8 SUBMITTALS
Test certificates, mill certificates, technical data sheets, source, supplier and manufacturer details shall be submitted prior to the start of the works. All certificates and documentation shall be in English. A Method Statement shall be provided detailing the Contractor’s proposed method of work regarding the piling works and the superstructure fabrication and assembly. This shall include but not be limited to the following information:
1 Programme of Works; 2 Details of the proposed source of the steel; 3 Details of the proposed anti-corrosion paint to be used; 4 Details of the proposed fabrication workshop of the superstructure elements; 5 Details of proposed shipping and handling of the components; 6 Details of the required additional geotechnical investigations; 7 Details and proposals for the method of socketing piles; 8 Details of proposals for the assembly of the superstructure.
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The information shown on Shop Drawings shall be complete and sufficient for the Supervising Engineer to review for compliance with Contract requirements. The information shall include but not necessarily be limited to the following; indicate layout, unit locations, locator key locations, fabrication details, unit identification marks, connection details, support items, dimensions, openings, and relationship to adjacent materials. The Contractor shall submit all records of surveys and site investigation to the Supervising Engineer. The Contractor shall provide details of all plant and equipment used to carry out the Work including independently certified Health and Safety documentation as required.
3.9 WELDING
All welding shall be full penetration Metal, Inert Gas (MIG), with either gas or gasless procedure in accordance with EN 1011-1. Welders shall be certified welders in accordance with the requirements of EN ISO 14732:2013. The caulking shall observe the following recommendations:
3.10 BOLTS NUTS AND WASHERS
All the nuts, bolts and washers shall be in stainless steel, Grade A4. The bolts in all the bolted connections shall be M20 DIN 933 A4, 70mm long. The nuts in the bolted expansion joints shall be DIN 985 A4 self-locking nuts. The nuts in the rest of the bolted connections shall be DIN 934 A4. Each nut and bolt connection shall include 2 DIN 125 A4 washers and 2 Polyamide washers.
3.11 SLIDING BEARING PADS
The sliding bearing pads in the expansion joints between the IPE 270 beam ends and the HEA 300 cross beam shall be in high-density Polytetrafluorethylene (PTFE) with a Shore Hardness D ≥ 51 as per ASTM D2240, with a tensile strength of 24 N/mm2 as per ISO 12086 / ISO 527.
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3.12 HOT DIP GALVANISED GRATING
The steel grating shall be manufactured from S 235 JR EN 10025-2 2004 structural steel and galvanised to EN ISO 1461. The bearing bar of the grating shall be a 60x4mm thick flat with a 6mm diameter transverse bar and a mesh size of 25 x 76mm.
The fixing clips shall consist of a heavy-duty anchor plate and a butterfly clip in AISI 316L stainless steel as shown in the figure opposite and held together by an M8 bolt in Grade A-4 stainless steel.
3.13 PAINTING
The preparation and application of all the paint cycles shall be in accordance with BS EN ISO 12944.
1 All the surfaces to be painted shall first be sand-blasted to ISO 8501-1 (2007) (Swedish Standard SA 2 /2).
The paint designation for the superstructure shall be ISO 12944-A5/A5M.06 EP/PUR:
• Primer Zinc rich epoxy primer • First coat Polyurethane coat (colour A) • Second coat Polyurethane coat (colour B) • Third coat Polyurethane coat (colour A) • Fourth coat Polyurethane coat (colour B)
Total coating thickness shall be 320 microns.
4. EQUIPMENT AND ELECTRICAL FITTINGS
4.1 BOLLARDS
The bollards shall be twin-head bollards in AISI 316L stainless steel with 4 x M20 DIN 933 A4 holding down bolts. The width of the base shall not exceed 130 mm. The length of the base may be defined by the supplier.
4.2 FENDERS
The types, basic dimensions, and locations of the fenders are shown on the relevant drawing HOB-11. The term fender is taken to mean the wing fenders to be bolted to the vertical piles.
The fenders shall be manufactured by an approved company. The fender supplier shall have the equivalent of an ISO-based quality assurance certification system.
The rubber raw material shall meet or exceed the performance requirements outlined in PIANC Report of Working Group 33: ‘Guidelines for the Design of Fender Systems: 2002’.The Fender Supplier shall submit a “Type Approval” certificate as per PIANC 2002 to the Employer and Contractor for approval
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Rubber for the fender elements shall be resistant to deterioration by oil, grease, ozone, UV radiation, sea- water, and aging. The grade of rubber for the fender elements shall comply with the requirements shown in the below.
PROPERTIES OF RUBBER
Standard (or Property Basic value Aged value equivalent) 15 N/mm2 12.8 N/mm2 minimum Tensile Strength DIN 53504 minimum for 168 hours at 70° C 350 % 280% minimum for Elongation at Break DIN 53504 minimum 168 hours at 70° C +5 increase 75 Shore A Hardness DIN 53505 maximum maximum for 168 hours at 70° C 80 N/cm Tear Resistance DIN 3507 - minimum Abrasion Resistance DIN 3516 100 mm³ - 40% maximum Compression Set DIN 3517 - for 22 hours at 70° C No cracks visible by eye Ozone Resistance DIN 53509 - (50 pphm at 20% for 40 hours at 40° C) Shore A: ±10maximum Seawater Resistance DIN 86076 - Volume: +10%/-5% maximum for 28 days at 95C ±2°C ASTM D430-95 15,000 cycles, Dynamic Fatigue - Method B grade 1
4.3 GALVANISED LIGHT POLES
The pole shall be made from hot dipped galvanised steel (minimum S235) and manufactured according to the following norms: • MSA EN 40 parts 1, 2, 3 and 5 • EN ISO 1461
The height above ground of the terminal end shall be 4.0 metres. The galvanising shall be integral and all holes shall be drilled therein before galvanising. All galvanising shall be carried out by the hot-dip process as specified in B.S. 729. The weight of coating shall be not less than 610gm/m2. Zinc for galvanising shall comply with BS EN 1179 (1996), Specification for zinc and zinc alloys.
All fittings, including mounting brackets, bolts, screws or studs shall be in AISI 316 stainless steel.
Sheradised or Passivated fittings shall not be used.
The pole manufacturer shall have an ISO 9001 quality system in place.
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4.4 OUTDOOR SOLAR FLOOD LIGHTS
The light units shall be of the all-in-one type fitted horizontally to the top of the light pole. The units shall be in vandal-resistant casings with a weatherproof housing (IP 55) and a built-in solar panel. The front luminaire shall be fitted with multiple SMD/LEDS rated at 18w power. The unit shall provide 790 Lumens at full brightness and 280 Lumens in ambient mode.
The unit shall be fitted with an 18 Watt solar panel. The system shall be equipped with a built-in charge control regulation with over-charge and discharge protection. All SMD/LED's shall have a colour temperature of 6000-6500k. Average light intensity shall be 30 Lux with a 120-degree viewing angle projected downwards and outwards for Zero light pollution. There shall be no lead or mercury in the alloy composition and the alloy material shall be 100% recyclable. Fittings shall be RoHS compliant.
The all-in-one solar units shall be equipped with sufficient bird spikes to prevent birds from roosting on the panels and fouling up the solar cells.
4.5 SOLAR-POWERED BEACON (RED)
The beacon shall incorporate a 155 mm 360 degree visibility red acrylic fresnel lens visible up to 3 nautical miles with a waterproof rating to IP68. All the bolt fittings on the unit shall be in AISI 316L. The lens shall be in UV stabilised polycarbonate. The solar panels shall be mono-crystalline potted with UV-protected polyurethane and domed for higher efficiency. The battery shall be a 15 Ah replaceable battery with an average life exceeding 5 years. The lantern should consist of a minimum 1x4 LED Array with 1Watt LEDs with a consumption not exceeding 6 Watts in steady burn. Fittings shall be RoHS compliant.
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The base of the lantern shall be in marine grade aluminium. The beacon shall be mounted on a double flanged 150mm diameter UV stabilised High-Density Polyethylene pipe bolted to a concrete base anchored to the reef in the position shown on the drawing Hob-02.
4.6 200Kg SWL HOIST
The manually-operated hoist shall be manufactured in galvanised Grade S355 steel or AISI 316L low- carbon austenitic stainless steel to BS 6744, Grade 500 with a minimum yield strength of 430 N/mm2. If galvanised steel is used, it shall be integral and all welding and holes shall be drilled therein before galvanising. All galvanising shall be carried out by the hot-dip process as specified in B.S. 729. The weight of coating shall be not less than 610gm/m2. Zinc for galvanising shall comply with BS EN 1179 (1996), Specification for zinc and zinc alloys. All fittings, including mounting brackets, bolts, screws or studs shall be in AISI 316 stainless steel.
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5. ASSEMBLY AND CONSTRUCTION
5.1 GENERAL DESCRIPTION
The general layout of the fisheries jetty is shown on Drawings HOB -02 and HOB -03 and consists of a 40 metre long steel jetty rooted at the rear of an existing reef, protected by a low wave wall anchored to the existing rock reef on an alignment in line with the small rock outcrop. Access to the jetty platform shall be via a short causeway curving into an access way on top of the reef. The access way shall be paved in concrete and shall not extend beyond the reef on to the sand dunes.
The jetty steel structure consists of a cross beam across 3 vertical piles and longitudinal beams spanning from each cross beam to the next, Drawings HOB 05 and HOB-06. The width of the jetty trunk shall be 6.50 metres and the jetty platform shall measure 10 metres by 19.50 metres in width.
The jetty deck shall be in steel grating, Drawing HOB -04, to eliminate uplift pressures and set at +3.0 m above Lowest Astronomical Tide level. The jetty platform shall be equipped with a simple mechanical hoist with a Safe Working Load of 200 Kg, 2 solar-powered flood lights, 4 twin-head bollards, and vertical fenders. The vertical piles shall be embedded into the bed rock by at least 500mm and grouted in place.
A red navigation light shall be placed at the end of the reef to assist in night time operations when high tides may occur, further improving the use of the jetty.
5.2 ORDER OF PROCEDURE
The Contractor shall construct the Works in the following sequence which is to be incorporated into the programme to be prepared by the Contractor in accordance with the provisions of the General Conditions of the Contract.
• Drill the wave wall anchor holes and grout the anchor bars for the wave wall (HOB-11); • Erect a template for the causeway walls and start building the walls with concrete-filled jute bags (HOB-11); • Complete the causeway walls and backfill with Grade 25 mass concrete mixed with 50% by volume of clean rock in the 5-50Kg range (“plummed” concrete) allowing space for the anchors of the first pile bent; • Complete the wave wall and cast the access way paving in concrete to provide driving access to the work area (the root of the jetty trunk), including the anchoring of the first pile bent; • Drill and excavate pile sockets as per drawings (HOB-04); • Erect scaffold towers over 3 sockets at a time, leveled off to receive a pre-assembled pile bent; • Assemble 1 pile bent and haul into position over sockets and grout the 3 sockets; • Repeat for the next 6 bents to complete the jetty trunk; • Assemble in place longitudinal beams and cross bracing for the entire trunk and anchor grating in place (HOB-05, 06 and 08); • Repeat procedure for platform; • Install fittings and navigation light.
The Contractor shall be responsible for ensuring that his methods, equipment and order of procedure do not in any way endanger the integrity of the newly built structures.
5.3 WAVE WALL
The general construction details of the wave wall are illustrated on Drawing HOB-11. The wall base shall be 700 mm wide and rise in 2 steps and rise to a level of +4.0 metres about LAT. The splash wall shall terminate around the start of the causeway to protect against rogue waves splashing over the paved access way.
Prior to the start of works on the wave wall, all loose rock shall be removed along a width of 1.0 metre along the proposed length of the wave wall. Anchor bars (Bar Code 101 on HOB-11) shall be installed along the axis of the outer face of the wall at 200mm centres as illustrated on Drawing HOB-11. The anchor bars shall consist of 12 mm reinforcing bars grouted in 35mm diameter boreholes, 500mm deep, drilled in to
- 10 - Rev [1] [Hobyo Fishing Jetty] [Scope of Works] the reef. The grout shall be a proprietary, pre-mixed, non-shrink grout. In-situ cement paste or concrete will not be permitted.
Timber or metal formwork shall be set up for the base slab and splash wall in Grade 35 concrete. The wave wall shall be cast in 1.0 metre sections and in 2 lifts, the base lift up to +3.50 and the splash wall lift up to +4.0 metres above LAT. The 1.0 metre sections shall be cast in alternate sequence. A 50mm chamfer shall be incorporated along the three exposed edges. The base shall be finished in a brushed finish and slope outwards to drain overtopping water.
5.4 CAUSEWAY AND ACCESS WAY
The general construction details of the causeway and access way are illustrated on Drawing HOB-11. The finished width of the road shall be 5.0 metres and shall be built on the existing rock outcrop as illustrated. The first phase shall consist in the erection of a template in scaffold tubing anchored to the rock reef for the formation of the inner face of the jute bag retaining wall. Once the template frame has been erected, the retaining wall in jute bags shall be erected up to kerb level of +3.20 metres. Every 2.50 metres, gaps in the kerb shall be left at +3.0 metres to drain any overtopped water away from the road surface.
The second phase shall consist in filling the causeway and access way with quarry waste up to level +2.88 metres. Any reef outcropping above this level within the 5.0 metre width of the road shall be cut away. Finally, the access road over the reef and causeway may be cast in Grade 35 concrete between the finished kerb and the wave wall. The concrete slab shall be 120 mm thick and laid to a 1:100 fall towards the kerb.
The concrete road on the reef shall not extend on to the sand dune.
5.5 SETTING-OUT
Throughout the execution and completion of the Works, the Contractor shall continuously keep an experienced surveyor on the site to perform and supervise the setting out and other surveying work. The instruments used by the Contractor shall be of a make and type suitable for the tasks to be performed and in sound technical condition and adjustment, to the satisfaction of the Supervising Engineer. The horizontal and vertical datum for the Works shall be the Datum as established on the Site during the survey campaign. All times shall be given in the local time zone (GMT+2hr).
The location and level of the primary level benchmarks (HB1 and HB2) is shown on the drawing HOB-02. The Contractor shall set out the whole of the Works relative to these points. In order to carry out his duties in accordance with the Contract, the Contractor shall, before construction commences, establish from the horizontal and vertical datum marks indicated, an adequate system of control points and benchmarks that shall be clearly marked, adequately referenced and properly recorded. The Contractor shall be solely responsible for these operations. He shall make the control points and benchmarks available to the Supervising Engineer together with the relevant records. The Contractor shall protect the above referenced point(s) and level benchmarks and in the event of any damage shall survey and re-establish the point(s). The accuracy of setting out and levelling shall be within the tolerances specified in BS 5606 or as called for in the Specification or directed by the Supervising Engineer where no standard is established.
Staking out Centre Line and Alignment and Level of the jetty - The Contractor, in conjunction with the local stakeholders and the Supervising Engineer shall be responsible for staking out the centre line of the jetty and for establishing the initial alignment and level of the causeway and access way at the root of the jetty. The Contractor shall be responsible for checking that all basic survey points are maintained in place for the duration of the Contract and if they become missing or appear to have been disturbed the Contractor shall report the details to the Supervising Engineer and make arrangements to re-establish the points. After the Supervising Engineer has agreed this basic survey and staking out, the Contractor shall be responsible for its maintenance and re-establishment of any portion lost or destroyed.
Reference pegs and benchmarks of basic points established by the Contractor shall be conical in shape measuring 450 mm in height, 300 mm at the base and 150 mm at the top, with a galvanized iron pipe or stiff rubber or plastic pipe 25 mm in diameter, centrally positioned at the top of the beacon. Beacons shall be set so that 200 mm projects above natural ground. The chainage, level and other markings required by the Supervising Engineer shall be scratched or clearly marked with paint on the surface of the concrete or
- 11 - Rev [1] [Hobyo Fishing Jetty] [Scope of Works] otherwise clearly marked to the satisfaction of the Supervising Engineer. Payment is meant to be included in the mobilisation item of the Bill of Quantities.
Setting Out - Prior to the construction of any work, the levels of the existing ground shall be agreed between the Contractor and the Supervising Engineer. If the Contractor fails to take the requisite levels, then the ground levels shown on the drawings or determined by the Supervising Engineer shall be taken as correct. If the Contractor removes or disturbs a benchmark without the prior permission of the Supervising Engineer, he shall be liable for the full cost of its replacement.
5.6 INFORMATION FROM EXPLORATORY BORING AND TEST PITS
When the Supervising Engineer directs that certain exploratory borings or test pits shall be carried out on the site of the works and certain results obtained are shown on the drawings or otherwise provided, any conclusions which the Contractor may draw from such information shall be used by him as his responsibility in determining levels, classifications, and characteristics of strata for any purpose of casting the piled foundations which are stated in the contract as being his responsibility.
5.7 WATER
It is the Contractor’s responsibility to provide water for the offices and for batching concrete. Hobyo has no public water utility and the Contractor’s attention is drawn to the fact that no separate payment will be made for the provision of all water required in and for the works. If the Contractor intends to use coastal well water for this purpose, the Contractor shall be responsible for testing the said water for chloride content. The limits for the chloride and sulphate content are described in the section for concrete.
5.8 HEALTH AND SAFETY ON SITE
The Contractor shall be responsible for the health, safety, and welfare at work of his employees including those of his subcontractors and of all other persons on the Site.
Health - The Contractor shall submit a copy of his Safety Policy document to the Supervising Engineer within 28 days after the date of the Letter of Acceptance. The Contractor’s responsibilities shall include:
• Measures to avoid health risks in connection with the use, handling, storage and transportation of harmful substances, including cement powder; • Provision and maintenance of safe and properly illuminated Contractor’s Equipment; • Provision and maintenance of safe access to all places on the Site; • Establishment of a safe and well-illuminated system of working; • Provision of protective clothing and equipment; • Appointment of a Safety Officer who shall have specific knowledge of safety regulations and have had experience of safety precautions on similar works and who shall advise the Contractor on all aspects of safety and health on Site; • Reporting details of any accident to the Supervising Engineer as soon as possible after its occurrence.
Safety - First Aid Facilities - The Contractor shall provide and maintain a first aid station at the area of main operations on the Site for the use of the Contractor's personnel and also those of the Supervising Engineer.
Fire Protection - The Contractor shall comply with the regulations of the Supervising Engineer and take all necessary precautions throughout the execution and completion of the Works when storing fuel on site to prevent an outbreak of fire and or pollution of the sea.
5.9 ENVIRONMENT
The Contractor shall allow for the provision of continuous and safe surface water drainage of the ground taking into consideration the technical requirements of the drawings and the stipulations of any permits so that no damage shall be caused either to the Works or its surrounding environment.
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The Contractor shall take full responsibility for the proper disposal of sewage arising from his operations from all places within the Site, or in connection with the Works and shall, at all times, comply with and adhere strictly to the principles of Best Management Practice. No public sewerage system exists in Hobyo.
The area seaward of the wave wall shall remain in its natural condition. The wave wall base and access road paving shall terminate on a rock. No permanent road access shall be constructed on the sand dune next to the reef.
During the execution and completion of the Works, the Contractor shall protect the environment on and off the Site from contamination all in accordance with National and International Conventions that may apply. Accordingly, he shall collect all kinds of waste, including oil and oil residues, production and communal wastes arising from his operations, dunnage and other plastic packaging and transport them away for re- cycling or dumping at a place approved by the Supervising Engineer. Mineral oil, oily residues, paints, paint cans, oily-rags and batteries of any kind shall be handled appropriately for proper re-cycling and/or disposal. Fuel shall not be stored near the water line. The Contractor shall not release, or permit to be released into the air, water and land area at or in the vicinity of the Site any toxic or harmful effluent or substance, and shall indemnify the Client against any claims or liability arising from any breach of this obligation.
5.10 CONTRACTOR’S ORGANISATION ON SITE
The Client will make available to the Contractor, free of charge, the facilities detailed hereunder:
• The Contractor shall use area(s) within the project limits in accordance with the local community.
The Contractor shall agree on the exact extent of the area(s) on site with the Supervising Engineer and the local community. The Contractor shall be responsible for obtaining all necessary permits and licenses. The Contractor shall provide all necessary offices, stores, workshop and other temporary works or facilities that he may need to construct the Works. Details of the location and proposed use of designated Working Areas shall be submitted to the Supervising Engineer for approval. The Contractor may require land outside the site for his offices, stores, workshops, assembly areas, and construction plant etc. All rent and other costs so incurred shall be at the expense of the Contractor. The Contractor shall provide and maintain for the duration of the works a basic quality control laboratory consisting of a cube crushing machine, steel cube moulds and curing tank. Throughout the construction of the Works, the Contractor shall provide and maintain for his staff appropriate sanitary facilities. All operating and maintenance expenses connected therewith (lighting, water supply, etc.) shall be borne by the Contractor. The Contractor shall make all his own arrangements for the provision of living accommodation and other amenities for his workforce of the Site, and all rent and other costs so incurred shall be at the expense of the Contractor. The Contractor shall provide adequate supplies of electricity at a suitable voltage, compressed air and water of approved quality for all operations to be undertaken to complete the Contract, including the provision of any cables, pipes, valves, meters, storage tanks, etc. The Contractor shall be responsible for entering into any agreements with the local community, and shall issue all notices and pay all fees, dues, rents, charges and other costs incurred thereby.
The use of any VHF radio communication equipment on site shall be subject to the approval of the Supervising Engineer and the relevant statutory authorities such as the Police and Customs.
When using radio equipment, the Contractor shall adopt frequencies allocated by the Police that will not interfere with local transmissions or other equipment of any type. Concrete testing facilities in Somalia do not cover the full spectrum of tests that may be required for the jetty works. The Contractor shall carry out all necessary tests as required and shall report to the Supervising Engineer the results of such tests before submitting materials and finished work to the Supervising Engineer for approval. The Contractor shall provide, maintain and remove on completion of the Works, continuous fencing, at least 2.0 m high, and adequate security lighting around the areas of work, storage, offices, etc, and appropriate security measures on access roads, but without prejudice to his obligations such as maintenance of free access for the Supervising Engineer, other contractors and any other persons entitled to such access. Where temporary fencing already exists around the Contractor’s working area, such fencing shall be
- 13 - Rev [1] [Hobyo Fishing Jetty] [Scope of Works] maintained during the period of the Contract and removed on completion of the Works. The area of the site offices, including hard-standings shall, as a minimum be gravel surfaced and drained. The Contractor shall provide and maintain all necessary watching and lighting. The Contractor shall be required to have at least one watchman at the main area of work at all times when work is not in progress. For work at night (especially during periods of spring tides when certain activities are programmed for implementation) the Contractor shall arrange adequate lighting with adequate reserve in case of failure.
5.11 ASSEMBLY OF STEEL COMPONENTS
The entire steel structure shall be bolted and cast in place. The assembly of the jetty does not require welding and no welding shall be carried out on any component of the jetty once the steel components are unpacked from their container. The Contractor shall submit to the Supervising Engineer his proposed methodology for the excavation of the pile sockets in bed rock. Following the excavation in the rock for the pile sockets, erection of the steel portals or pile bents shall follow thus:
Three scaffold towers (or 1 large one) shall be erected over 1 set of 3 sockets as indicated in the diagram. An HEA300 Cross Beam shall be bolted to 3 vertical piles to form a portal and lifted into a position as shown over the sockets. The top level of the Cross Beam shall be +2.67 and the assembled beam shall be laid square with the axis of the jetty. Once the Supervising Engineer is satisfied that the pile bent is in its exact position, the sockets shall be grouted. The contractor shall ensure that at least 500 mm of the pile are inside the socket. The Grade 35 concrete in the sockets shall contain an anti-shrinkage additive (Sika Intraplast Z or similar approved). If the Contractor intends to make any changes to the above methodology, he shall submit his proposals to the Supervising Engineer for the latter’s approval. All the lifting slings shall be in polyamide webbing to ensure that no damage occurs to the paint work. Steel cable and chains shall not be used anywhere during the assembly, lifting and handling of the steel sections.
When at least 7 days have elapsed, the scaffold template may be removed and re-erected for the next bent. Conversely, if the IPE270 beams are bolted in position over 3 spans, the scaffold template may be removed after 1 day. When at least 3 bents are socketed, the longitudinal beams (IPE270) may commence placing, followed by the cross bracing, grating and railings. The longitudinal beams are fixed at the centre and slide at either end to compensate for expansion, see Drawing HOB-07.
The lock nuts at the expansion joints (DIN 985 A4) shall be tightened to a gap of 0.50 mm. The final tolerances of the jetty cope lines shall be as follows:
Alignment: • toward water 5mm over a 10 metre span Level: • +/- 2.5 mm over a 10 metre length
The first pile bent shall be anchored horizontally to the causeway via UC 100x50 channels bolted to the first row of piles and embedded inside the causeway “plummed” mass concrete.
Jetty Trunk Platform Portals Portals
Cross Beam
3 vertical piles bolted to Cross beam
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Each pile bent shall be pre-assembled and lifted into position by crane over the sockets
Top of Cross Beam at level +2.67 Cross Beam
3 Sockets excavated 2.25 m 2.25 m
Each pre-assembled pile bent shall be suspended over the sockets and leveled So that the top of the cross beam is perfectly horizontal at level +2.67
5.12 SITE MEETINGS AND PROGRESS REPORTS
The Contractor shall submit to the Supervising Engineer one (1) soft copy in English of a regular Monthly Progress Report not later than seven (7) working days after the end of the month to which the report relates, detailing progress on the various parts of the jetty Works in relation to the Contractor's Programme. The progress report shall include the following information: • Report on progress of each part of the Works including dates and principal operations, together with Subcontract work and outputs of main activities; • General report, including weather records, summaries of staff, labour and Contractor’s Equipment employed on Site with dates of arrival and departure and summaries of principal materials and manufactured items placed on Site; • Updated versions of the programme to show progress during the month and cumulative progress to date, all in a form approved by the Supervising Engineer. • Contained in each Monthly Progress Report, the Contractor shall submit a maximum of 10 progress photographs.
Progress meetings shall be convened by the Supervising Engineer or his Representative at Hobyo at regular intervals to suit the Contractor’s work schedule. The purpose of the meeting will be to review the Contractor’s Monthly Progress Report, to discuss the Contractor's programme and to cover such other matters under the Contract as may be specified or notified by either the Supervising Engineer or the Contractor. The agenda for each meeting will be prepared by the Supervising Engineer or his Representative with a copy to the Client’s Representative and the Contractor.
Progress meetings shall be attended by the Contractor's Project Manager or Site Agent, the Client’s Representative and the Supervising Engineer or his Representative. The Supervising Engineer or his Representative shall prepare minutes of the meeting which shall be agreed with the Contractor and the Client’s Representative not later than seven (7) days following the meeting.
Any minutes of the meeting or parts thereof signed both by the Contractor and the Site Engineer's and Employer’s Representatives as correct and sufficient shall constitute an authorised record of matters discussed, but shall not replace any requirement in the Contract for requests for approval, approvals, instructions or decisions to be submitted in writing. The Contractor shall copy all correspondence, notices, and documents to the Client unless otherwise directed in writing by the Client.
The Contractor shall take colour photographs every month showing the progress of the Works. Where necessary the Supervising Engineer shall indicate the subject matter of the photographs and select the vantage point.
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5.13 CLEAN DOWN
Upon completion, all exposed work in connection with the contract shall be thoroughly cleaned down and any matters which may in the opinion of the Supervising Engineer require attention shall be carried out so that the Works may be satisfactorily and fully completed in accordance with the Contract Documents. Particular attention shall be paid by the Contractor to keeping the exposed surfaces of the permanent work free from extraneous cement mortar and cement scum.
6. CONCRETE
6.1 GENERAL
This section covers the supply by the Contractor of all the materials and equipment necessary for the construction of all the civil works in concrete and steel. The reinforced concrete shall comply with the requirements of the British Standard Code of Practice (C.P. 8110) or relative Eurocodes or equivalent national standard. Concrete shall consist of cement; graded aggregate and water thoroughly mixed placed and compacted as specified in the following clauses.
6.2 CEMENT
The cement to be used throughout the works shall be Sulphate Resisting Cement (or Low Heat Cement) complying with B.S. 4027 and additionally with the alkali content, expressed as Na2O + 0,658 K2O, not exceeding 0,60% of the weight of the cement. The maximum chloride content shall not exceed 0.02% the weight of the cement. The content of tri-calcium aluminate, expressed as C3A, shall not exceed 10% the weight of the cement and nor be less than 5%. The content of tri-calcium sulphate, expressed as the sum of C3A + 0,27(C3S) shall not exceed 23,50% The specific surface area shall not exceed 325 m2/Kg when tested in accordance with B.S. 4550 Part 3. In other respects, the cement shall comply with B.S. 12. Rapid hardening or other special cements shall not be used.
Manufacturer's certificates of the test will, in general, be accepted as proof of soundness, but the Supervising Engineer may require additional tests to be carried out on any cement which appears to him to have deteriorated through age, damage to paper bags, improper storage or for any other reason. The Supervising Engineer may without tests being made, order that any bag of cement, a portion of the contents of which has hardened, or which appears to be defective in any other way, be removed from the site forthwith. The cement shall be transported to the site in covered vehicles adequately protected against water. It shall be stored in a weather-proof cement store to the approval of the Supervising Engineer and shall be taken for use in the Works in the order of its delivery into the store. Cement required for use within 24 hours may be stored in the open on a floor raised 30 cm. above ground, if covered by tarpaulins.
CEMENT TESTING
All cement shall be certified by the manufacturer as complying with the requirements of the appropriate specification. Before orders are placed the Contractor shall submit details on the proposed Supplier(s) together with such information that the Supervising Engineer may need to satisfy himself that the quantity and quality required can be supplied and maintained throughout the construction period. Where necessary the Supervising Engineer may require further representative samples of the proposed cement to be taken and forwarded to a nominated laboratory for analysis and testing before the source is approved. Having obtained the Supervising Engineer's approval of the source(s) of supply, transport, storage, and certification of the cement, the Contractor shall not modify or change the agreed arrangement without first having obtained the Supervising Engineer's permission. In addition to routine test certificates which are to be supplied by the manufacturer to show the average results of sample tests made on batches of cement produced at the works, the Supervising Engineer may also make further tests which he shall consider necessary or advisable to satisfy himself that the cement on site complies with the Specification and has not suffered deterioration in any manner during transit or storage. The Contractor shall ensure that the arrangements for the storage of the cement on Site as hereinafter specified are sufficient for the segregation and identification of each consignment until the results of the sampling and testing are available. No cement shall be used in the works until the Supervising Engineer has passed it as satisfactory.
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CEMENT STORAGE
The cement shall be delivered to the site of the works in bulk or in sound and properly sealed bags and while being loaded or unloaded and during transit to the concrete mixer whether conveyed in vehicles or by mechanical means, must be protected from the weather by effective coverings. Where directed by the Supervising Engineer the Contractor shall supply and erect efficient screens at his own expense to prevent wastage of cement during strong winds. If the cement is delivered in bags, the Contractor shall provide at his own cost perfectly weather-proof and well-ventilated sheds having a floor of wood or concrete raised at least 500mm above the ground. The sheds shall be large enough to store sufficient cement to ensure continuity of work and each consignment must be stacked separately therein to permit easy access for inspection, testing, and approval. On delivery at the site, the cement shall at once be placed in these sheds and shall be used in the order in which it has been delivered. The cement which has been damaged in transit to the site or has become stale or otherwise unsuitable, and hardened lumps or cakes of cement, which cannot be crumbled into a fine powder in the hand, shall not be used in the Permanent Works except with the specific approval of the Supervising Engineer.
6.3 AGGREGATES GENERAL
The fine and coarse aggregates shall be crushed sand, gravel or stone, and shall comply with the requirements of BS 882 ' Concrete Aggregate From natural Source'. They shall be obtained from a source approved by the Supervising Engineer, and shall be hard, strong, durable, clean and free from adherent coatings, or harmful organic impurities and shall not contain any harmful material in such a form or sufficient quantity as to affect adversely the strength, durability or permeability of the concrete or attack the steel reinforcement. They shall not contain water-soluble sulphur trioxide (S03) in excess of 0.1 percent. Beach or dune sand and/or river gravel shall not be used.
FINE AGGREGATE
The fine aggregate shall not contain silt or other fine material exceeding 6 percent by volume when tested according to the Standard Method given in B.S. 812 Clause 15; neither shall it contain organic material in sufficient quantity to show a darker colour than the Standard Depth of colour No.3 when tested according to the method in B.S. 812 Clause 28 "Organic Impurities'. Fine aggregate shall be clean sand complying with B.S. 882 "aggregates from natural sources for concrete". The sand shall be from approved sources and sand, which in the opinion of the Supervising Engineer is not clean, shall be washed before use. Crushed sand up to a maximum of 50% may be added to natural sand in order to achieve the required grading. Crushed sand alone may only be used with the approval of the Supervising Engineer. Sand for use in mortar and rendering shall conform in all respects with B.S. 1198-1200, "Building sands from natural sources". Fine aggregate subjected to five cycles of the soundness test, specified in ASTM C88 shall not show a loss exceeding 10% when magnesium sulphate solution is used except where otherwise approved.
GRADING OF FINE AGGREGATE
The grading of fine aggregate shall be within the limits given in the following Table
GRADING OF FINE AGGREGATES
B.S. Sieve Percentage by Weight Passing B.S. Sieve
Natural Sand or Crushed Stone Sand Crushed Gravel 5mm 95 – 100 90 – 100 No.7 70 – 95 60 - 90 No.14 45 – 85 40 – 80 No.25 25 – 60 20 – 50 No.52 5 – 30 5 – 30 No.1000 0 – 10 0 – 15
COARSE AGGEGATE
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The coarse aggregate shall be a hard stone from a source approved by the Supervising Engineer. The aggregate shall not contain clay lumps exceeding 1% by weight. A representative dry sample shall not show an increase in weight exceeding 8% after immersion in water when tested as laid down in B.S. 812 Clause 19-21. It shall be well shaped and not flaky. The nominal size of coarse aggregate shall be as stipulated below. Coarse aggregate shall comply with B.S. 882 "Aggregates from natural sources for concrete". Subject to sub-clause (4) hereof it may be either natural gravel crushed or part crushed gravel or crushed rock and shall be obtained from quarries, pits or other sources approved by the Supervising Engineer. Gravel or ballast shall be free from clay, earth, loan or other organic or similar material and shall be approved by the Supervising Engineer. Grave or ballast, which in the opinion of the Supervising Engineer is not clean, shall be thoroughly washed before use. The grading of coarse aggregate by analysis shall be within the limits laid down in B.S. 882, Table 4, and “Coarse Aggregate". The material shall when mixed with sand produce a well-graded mixture from the largest to the smallest size specified to ensure that concrete or high density shall be produced. The "flakiness index" for coarse aggregate as determined by the sieve method described in B.S. 812 "Methods for sampling and testing of mineral aggregates, sands, and fillers", shall not exceed 40 for 40mm aggregate or 35 for 20mm and 10mm aggregate. "The elongation Index" for coarse aggregate determined in accordance with B.S. 812 shall not exceed 36. The coarse aggregate shall have a "ten percent fines" value of not less than 100 KN. the value shall be determined as described in BS 812. Coarse aggregate subjected to five cycles of the soundness test, specified in ASTM C88 shall not show a loss exceeding 10% when magnesium sulphate is used except where otherwise approved.
GRADING OF COARSE AGGREGATE
The grading of coarse aggregate shall be within the limits given in the following Table
GRADING OF COARSE AGGREGATE
Percentage by weight Passing B.S. Sieve
B.S. Sieve Nominal Size of Graded Aggregate
38mm to 5mm 1.9mm to 5mm 75mm 100 - 38mm 95 - 100 - 19mm 30 - 70 95 – 100 10mm 10 - 35 25 – 35 5mm 0 - 5 0 – 10
ALKALI AGGREGATE REACTIVITY
Aggregate shall not contain any matter, which in the opinion of the Supervising Engineer is likely to undergo disruptive reactions with alkali in the concrete mix or which is likely to otherwise affect the long-term durability of the concrete.
ACCEPTABILITY
Notwithstanding that the coarse and fine aggregates may each separately comply with the requirements stated above, they will not be accepted unless when mixed together in suitable proportions the combined aggregates produce uniformly graded and compacted dense concrete or the strength required with adequate workability for the position.
SAMPLES OF AGGREGATE
Samples of the fine and coarse aggregates approved by the Supervising Engineer shall be kept on site and shall give a fair indication of the general quality of the aggregates for comparison with the aggregates delivered during the course of the work. Tests shall be carried out on samples of the latter taken at intervals as required by the Supervising Engineer. The method of sampling and the amount of aggregates to be provided for the tests shall be in accordance with BS 812 Section One "Sampling and Aggregates". The tests shall be those laid down in BS 812 Section Two to Six inclusive. The Supervising Engineer or his representative shall carry out the tests. Should a sample fail to comply with any of the tests, the
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Supervising Engineer may, at his discretion, either reject the batch from which the sample was taken, order it to be washed and/or screened or permit to be used with variations in proportions of the concrete mixes specified. Any batch of aggregates rejected by the Supervising Engineer shall be removed from the Works site forthwith.
STORAGE OF AGGREGATE
The fine and coarse aggregates shall be stored in properly constructed open bins in hard, clean drained floors or in such a manner that they shall not become contaminated with any deleterious and extraneous matter. Furthermore, stockpiled aggregates shall not be exposed to windborne sea spray in order to prevent the accumulation of salt in the mix.
6.4 WATER
The water shall be clean and free from harmful matter and shall be from a source approved by the Supervising Engineer. The Contractor shall make adequate arrangements to deliver and store sufficient water at the Works Site for use in mixing and curing the concrete. Water shall comply with the requirements of the latest edition of BS 3148 or equivalent standard. Local well water shall not be used unless tested and approved by the Supervising Engineer.
CHLORIDES
The acid-soluble sulphate content (SO3) of the water shall not exceed 500mg/litre and the acid soluble chloride ion content shall not exceed 350mg/litre. These limits shall be subject to the overall limit given for the concrete.
The acid-soluble sulphate content (SO3) in the aggregate shall not exceed 0,40% by weight. The acid soluble chloride ion content in the aggregate shall not exceed 0,02% by weight for coarse aggregate and 0,04% for fine aggregate.
The total chloride content of all the constituent materials in the mix shall not exceed 0,70% the weight of the cement. The total sulphate content shall not exceed 3,0% the weight of the cement.
6.5 CONCRETE
The concrete for structural works shall be designated mixes, which will comply with the minimum requirements specified. The Contractor shall design the mixes to comply with the Specifications and shall submit to the Supervising Engineer or his representative his proposed designs for provisional agreement. Following tentative approval of the mix design of each class of concrete by the Supervising Engineer, the Contractor shall prepare a trial mix of each class of concrete in the presence of the Supervising Engineer's representative. The preliminary or trial mixes should generally give a strength 25% higher than the specified "Works" strength. Each trial mix shall comprise not less than half a cubic metre of concrete and shall be mixed in a mechanical mixer of a type approved by the Supervising Engineer.
The quantities of all the ingredients of each trial mix including water shall be carefully determined by weight according to the approved mix design and sieve analysis and shall be made by the method described in BS 812. Six 150mm test cubes shall be made by the Contractor in the presence of the Supervising Engineer from each trial mix. The cubes shall be made, cured, stored and tested for their compressive strength three at 7 days and the other three at 28 days after manufacture, all according to the method described in BS 1881. The Contractor shall redesign the mix and make a further trial mix and test cubes.
1. if the value of the ultimate compressive strengths of any of the cubes is less than the appropriate design strength, or 2. if the difference between the greatest and least compressive strengths of any of the six cubes of a set is greater than 15% of the average compressive strength of the six cubes.
The Contractor shall allow ample time in his programme for designing and making trial mixes and the preparation and testing of compressive strength test cubes obtained there from. The batches are to be gauged appropriately to obtain the strengths specified in the table below:
The Supervising Engineer may require allowance to be made in the gauging of the aggregate to counteract the increase in volume (often termed "bulking") due to moisture content. The Classes of concrete to be used in the Works shall be as shown on the Drawings, Bills of Quantities or as directed by the Supervising Engineer. For each class of concrete, the characteristic 28-day crushing strengths are obtained when tested in accordance with the following clauses.
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The term characteristic strength means the value of the strength of concrete below, which not more than 5 percent of the test results fall. The characteristic strengths specified above are for concrete cured at a mean temperature between 25oC and 30oC and at relative humidities of 70% to 90%. Should the curing temperature and humidity be less than or higher than the above ranges, the acceptable cube strength shall be modified by an amount acceptable to the Supervising Engineer. The actual cement contents and aggregate/cement ratios will depend on the closeness of control, which the Contractor is prepared to exercise in production and upon the quality of materials used. Where necessary the Supervising Engineer may impose an upper or lower aggregate/cement ratio, which shall not be exceeded for any class of concrete.
Before any concrete is placed in the Works the Contractor shall submit to the Supervising Engineer for his approval full details of the mixes he proposed to use for each class of concrete together with their expected average strengths. These mixes shall be based on the results of trial mixes as specified hereafter.
TEST FAILURE
If three or more consecutive results are below the characteristic strength an immediate examination shall be made to find the cause of the failure and a report sent to the Supervising Engineer's Representative in Hobyo who will take suitable action which may be one of the following:
a. The adjustment of the mix and/or improvement to the standard of quality control. b. The concrete corresponding to the cubes is cut out and replaced.
COST OF TESTING
The price for concrete shall include the supply of disposable test cubes, slump cones and for carrying out all the tests specified as and when required to the satisfaction of the Supervising Engineer and for making, curing and shipping the test cubes to a certified laboratory in Mogadishu.
TESTING OF WORKS CONCRETE
The consistency of the works concrete shall be determined at all times by means of the standard slump test. For normal concrete, the slump shall not exceed 75mm; for mechanically vibrated concrete, the slump shall not exceed 50mm. The strength of the works concrete shall be determined by the testing of 150mm specimen test cubes taken from the concrete at random during the progress of the work. One such cube shall be taken from each day's concreting or for each 15m3 of concrete placed, whichever is less. The cubes shall be tested at 28 days age. The method of making, marking, recording, curing and testing the cubes is to be agreed with the Supervising Engineer before the commencement of concreting work. The test cubes referred to above, made, cured and tested in accordance with the foregoing provisions, shall show, to the satisfaction of the Supervising Engineer, that the concrete complies with the following minimum requirements. The Slump and Cube tests shall be carried out in accordance with B.S. 1881.
NOMINAL COMPOSITION AND CHARACTERISTICS FOR GRADE 35 CONCRETE
NOMINAL GRADE 35
SPECIFIED WORKS CUBE STRENGTH AT 28 DAYS 35 N/mm2
ALTERNATIVE MINIMUM CUBE STRENGTH AT 7 DAYS 20 N/mm2
MAXIMUM AGGREGATE SIZE 10 mm
LIMIT OF RATIO BY WEIGHT OF AGGREGATE TO CEMENT 3,8-5,1
MAXIMUM WATER-CEMENT RATIO 0,45
COMPACTING FACTOR 0,78-0,92
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SLUMP 25-50 mm
CEMENT CONTENT 350 Kg/m3
ADMIXTURE 4,0 Lt/m3
NOMINAL COMPOSITION AND CHARACTERISTICS FOR GRADE 30 CONCRETE
NOMINAL GRADE 30
SPECIFIED WORKS CUBE STRENGTH AT 28 DAYS 30 N/mm2
ALTERNATIVE MINIMUM CUBE STRENGTH AT 7 DAYS 16 N/mm2
MAXIMUM AGGREGATE SIZE 20 mm
LIMIT OF RATIO BY WEIGHT OF AGGREGATE TO CEMENT 4,5-6
MAXIMUM WATER-CEMENT RATIO 0,45
COMPACTING FACTOR 0,85-0,92
SLUMP 50-100 mm
CEMENT CONTENT 300 Kg/m3
ADMIXTURE 4,0 Lt/m3
NOMINAL COMPOSITION AND CHARACTERISTICS FOR GRADE 25 CONCRETE
NOMINAL GRADE 25
SPECIFIED WORKS CUBE STRENGTH AT 28 DAYS 25 N/mm2
ALTERNATIVE MINIMUM CUBE STRENGTH AT 7 DAYS 14 N/mm2
MAXIMUM AGGREGATE SIZE 20 mm
LIMIT OF RATIO BY WEIGHT OF AGGREGATE TO CEMENT 4,5-6
MAXIMUM WATER-CEMENT RATIO 0,45
COMPACTING FACTOR 0,85-0,92
SLUMP 50-100 mm
CEMENT CONTENT 250 Kg/m3
ADMIXTURE 4,0 Lt/m3
WATER/CEMENT RATIO
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The Maximum Water/Cement Ratio for all the concrete mixes unless otherwise specified shall be 0.45. Efficient means shall be provided for determining the moisture content and absorption values of the sand and coarse aggregate at all times. The Contractor shall be required to have a fairly accurate knowledge of the moisture content of all sand and coarse aggregate as they reach the mixer and he shall make such adjustments to the mix as are necessitated by a change in the moisture content of all aggregate.
WORKABILITY
The concrete shall be of such consistency and composition that when vibration has used the surface of the wet concrete should shimmer, the concrete sliding about, engulfing bars, wrapping them without difficulty and yet at the same time the mix should appear to hang together and no watery scum appears on the surface. Where concrete starts jamming between reinforcement or between reinforcement and shuttering great care shall be taken to ensure that these lumps are dislodged and a more workable and flowing mixture introduced. The water/cement ratio must be kept to a minimum compatible with strength and workability.
MIXING AND PLACING OF CONCRETE
The aggregates are to be measured by weight; the weight of aggregates per batch must be accurately determined and agreed with the Supervising Engineer. The batching equipment shall work to the following limits of accuracy:
Cement +/- 1% by weight Aggregate +/- 2% by weight Water +/- 1% by weight
The equipment shall be capable of combining the aggregates, cement, water, and admixture within the time allowed for mixing and discharging without segregation. The water shall be inserted into the mix through an approved type of metering system which shall also be capable to discharge small increments of water when required. The water content of the aggregates shall be taken into consideration when gauging the quantity of water to be added to the mix.
CONSISTENCY
The Contractor shall carry out slump tests as required during concreting of permanent works in order to relate the degree of workability of the mix with the numerical value obtained during the trial mixes.
RECORDS
The Contractor shall send weekly to the Supervising Engineer a return showing the quantities of cement and the number of mixings of each class of concrete used in each section of the works. Records shall be kept by the Contractor of the position in the works of all batches of concrete of their class and of all test cubes or other specimens taken from them. Copies of these records shall be supplied to the Supervising Engineer.
INSPECTION BEFORE PLACING
At the end of each day, the Contractor shall give the Supervising Engineer a realistic concreting programme for the next day. Also, notice shall be given to the Supervising Engineer when formwork and reinforcement are complete and ready for inspection to receive at least 24 hours before concrete is to be placed.
DEPOSITING OF CONCRETE
This contract does not envisage the placement of concrete underwater. The arrangements for placing concrete in the pile sockets are to be such that placing will take place at low tide only. Placing shall not take place during the flow and ebb of the tide to prevent washout. Protection against possible wave wash must be provided in the form of sand bags around the socket hole. The concrete to be deposited under the water line shall be Grade 35 as specified in the Table of Concrete Mixes. Sockets – The pile sockets shall be clean of sand and other debris and pumped dry before concrete is poured in place. An air-operated diaphragm pump should be used for this purpose as soon as the tide level allows for the work to proceed in the dry.
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Causeway – The concrete retaining walls for the causeway shall be in Grade 30 mass concrete placed in sealed hessian bags in a brick wall fashion. The concrete mix design shall be such that the concrete shall be sufficiently dry to be placed inside a jute bag. Concreting shall be carried out in sections previously ordered or approved by the Supervising Engineer and shall proceed continuously in each section until completed. The causeway infill shall consist of Grade 25 concrete with sound rock plums replacing 50% by volume of the concrete mass.
NO PARTIALLY SET CONCRETE TO BE USED
All concrete must be placed and compacted within 30 minutes of water being added to the mix unless admixtures are in use. If plasticiser/admixture is used, tests shall be carried out to determine the initial setting time. No partially set material shall be used in the works.
CONCRETING IN ADVERSE WEATHER
No concreting should take place in the open during:
1. strong winds; 2. heavy rains; 3. peak mid-day temperatures (above 40oC).
Where strong winds are likely to be experienced additional precautions to ensure protection from driving rain and dust shall also be taken. When ambient temperatures exceed 40oC, no concreting will be allowed after 10 am or before 4 pm. The Supervising Engineer may withhold approval of commencement of concreting. If the tide table indicates that the next spring tide (suitable for concreting the sockets) will occur under the above conditions, the Supervising Engineer shall be informed beforehand.
CONCRETING IN THE DARK OR AT NIGHT
Where approval has been given to carry out concreting at night, the Contractor is to provide adequate lighting at all points where mixing, transportation and placing of concrete are in progress.
CONSTRUCTION JOINTS
Construction joints shall be located in the paving of the accessway and causeway as shown in the drawing. Such joints shall be in a plane at right angle to the axis of the paving. The horizontal joints shall have all excess water and laitance removed from the surface after the concrete has been compacted and before it has set. The Contractor shall ensure that construction joints are formed every 5 metres of casting.
CURING AND PROTECTION OF CONCRETE
Exposed surfaces, immediately after final set, shall be protected from the sun in a manner approved by the Supervising Engineer. All concrete shall be well watered after it has set and shall be kept continuously damp until thoroughly cured. Provision shall be made for adequate water distribution to all parts of the work, so that, if required this treatment can be continued efficiently throughout the whole period of construction. In order to keep the concrete continuously damp, all exposed surfaces shall be covered with continuously damped hessian sacks or shall have water impounded on them, for the full period of curing, which shall not be less than 10 days. All work shall be protected from damage by shock, overloading, etc.
SURFACE TREATMENT AND FINISH
The top surfaces of the causeway slabs shall be floated to a smooth finish with a wooden float after compaction of the concrete and laid to a slope of 1:100 towards the drainage channels in the in-situ kerb. The wooden float troweling shall be carried out after the concrete has stiffened and the film moisture has disappeared. Working should be kept to a minimum compatible with a good finish and the surface shall be true to the required profile tolerance. Whenever necessary, the Contractor shall provide and erect overhead covers to prevent the finished surface from being marred by raindrops or windborne sand. When the required setting time has elapsed, the surface shall be brushed with a stiff broom to impart to the concrete surface a brushed finish.
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ADDITIVES
The use of additives in the concrete, for the purpose of promoting workability or for other reasons, is permitted. Such additives shall be of a brand and type approved in writing by the Supervising Engineer and shall be used strictly in accordance with the maker's instructions, and be used only subject to such preliminary tests as the Supervising Engineer may require before permission is given to using the additives, in any part of the structure.
CEMENT GROUT
Cement grout for anchoring of the wave wall dowels shall consist of a water/cement admixture using a non-shrink additive in the proportion recommended by the manufacturer. The grout shall be used within one hour of mixing.
DEFECTIVE CONCRETE
Should the concrete appear honeycombed after the removal of the formwork, the Contractor shall if so ordered by the Supervising Engineer, replace at his own expense all the work deemed unacceptable.
BREAKING OUT OR SCABBING OF BAD CONCRETE FOR REPAIR WORKS
Where existing concrete is to be broken out prior to carrying out repair works the precise extent of such breaking out shall be agreed by the Supervising Engineer. The edge of broken out sections shall be formed square to provide a neat finish. Concrete shall be broken back carefully to expose a sound surface. Where existing steel reinforcement is to be retained breaking out of concrete shall be carried out carefully to cause no damage to reinforcement.
6.6 REINFORCEMENT
This section covers the supply, cutting and placing of the reinforcement of the shape and dimensions shown on the drawings and plans and as specified in these Specifications and other special provisions.
REBARS
1. Reinforcing steel bars for concrete shall be deformed billet-steel bars, hot-rolled or cold worked, low alloy steel deformed bars, or hard drawn mild steel bars. 2. Bar reinforcement, welded wire fabric and reinforcing wire shall conform to the following requirements: i. Hot-rolled steel bars to B.S. 4449 or equivalent; ii. Cold worked steel bars to B.S. 4461 or equivalent; iii. Hard drawn mild steel wire to B.S. 4482 or equivalent; iv. Steel welded fabric to B.S. 4483 .
BENDING SCHEDULES
The Supervising Engineer will provide the Contractor with bending schedules showing the location, types, sizes, bending dimensions and cut lengths of the reinforcement required to be fixed in the Works, designed by the Supervising Engineer. The Contractor shall check each bending schedule against the relevant drawing and shall notify the Supervising Engineer that the bending schedule is correct, or inform him of any discrepancies. In particular, the Contractor may be required to modify the schedules with respect to any reinforcement starting bars he may consider necessary after obtaining the Supervising Engineer's Representative's approval. The Contractor shall, however, produce bending schedules for reinforcement designed by him. The Contractor shall be responsible for providing additional bending schedules and all details and lists of reinforcing bars which may be required in addition to those shown on the Drawings and for providing bar bending schedules in accordance with B.S. 4466. The provision of these shall not relieve the Contractor from his responsibilities for providing the materials as detailed on the Drawings in accordance with the contract.
INSPECTION OF FABRICATION
Except when otherwise ordered by the Supervising Engineer, reinforcing steel will be inspected at the fabrication site. The Contractor shall notify the Supervising Engineer in sufficient time to permit this inspection before shipment is made. A nominated Inspector may carry out the said inspection on behalf of
- 24 - Rev [1] [Hobyo Fishing Jetty] [Scope of Works] the Supervising Engineer. The inspection of reinforcing steel by the Supervising Engineer at the fabrication site, shall not preclude the subsequent rejection of the said steel if either the materials or fabrication are found defective.
TESTING REINFORCEMENT
The Contractor shall furnish the Supervising Engineer with copies of the Manufacturer's Certificate of Compliance for the steel reinforcement to be supplied. Any consignment not complying in all respects with the appropriate foregoing Specifications shall be removed from the site at the Contractor's expense within 24 hours upon notification to do so by the Supervising Engineer.
BENDING REINFORCEMENT
Reinforcement shall be cut and bent to the shapes and dimensions shown on the finally agreed bending schedules. All reinforcement shall be carefully bent to the correct dimension in a manner, which will not injure the material. In particular, no reinforcement shall be heated before bending. Bends on reinforcement bars shall be carefully formed in accordance with the Drawings, B.S. 4466 "Bending dimensions and scheduling of bars for the reinforcement of concrete" and B.S. 8110, Part 1". The Structural use of concrete". The bars shall not be bent or straightened in a manner, which will injure the material. Bending hot at cherry red heat (i.e. not exceeding 840oC) may be allowed except for bars, which depend for their strength on cold working. Bars bend hot shall not be cooled by quenching. Bends shall be made round a former having diameter of at least four times the diameter of the bar except for bends in cold twisted steel bars and deformed bars of high tensile steel for which a former of at least six times the diameter of the bar shall be used. Where splices of overlapping in reinforcement are required, the bars shall, unless otherwise shown on the Drawings, have an overlap of not less than thirty diameters where a U-hook is employed in each of the overlapping bars and forty-five diameters for bars without hooks.
Fabric reinforcement sheets shall overlap by two meshes or 300mm whichever is greater.
FIXING OF REINFORCEMENT
The number, size, form, and position of all steel reinforcing bars, ties, links, stirrups and other parts of the reinforcement shall be in exact accordance with the Drawings and they shall be kept in the correct position and with the required cover without displacement during the process of compacting the concrete in place in a manner approved by the Supervising Engineer. The Contractor shall provide all necessary distance pieces and spacer bars at his own cost to maintain the reinforcement in the correct position. The type of distance pieces shall be subject to the approval of the Supervising Engineer. Timber blocks for wedging the steel of the formwork shall not be taught so that the bars are properly braced and the inside of the books and bends shall be in actual contact with the bars around which they are intended to fit. Bars shall be bound together with best black annealed mild steel wire and the binding shall be twisted tight with pliers. The free ends of binding wire shall be bent inwards. Before any steel reinforcement is embedded in the concrete any loose mill scale, loose rust and any oil, grease or other deleterious matter shall be removed, by grit blasting, mechanical wire brushing and/or washing. Partially set concrete, which may adhere to the exposed bars during concreting operations, shall likewise be removed.
Concrete Spacer Blocks may be used to ensure that the concrete is correctly positioned in the works and shall be as small as possible consistent with their purpose. Such blocks shall not exceed 50mm in length and their thickness shall be exactly that required to give the cover specified on the Drawings. Each spacer block shall be made of Concrete Class 35/10 and binding wire shall be securely embedded into each block to permit adequate fastening to the reinforcement bars.
6.7 JUTE BAGS
The jute or hessian fabric sandbags for use in the causeway perimeter walls shall conform to BS 1214- 1977 and be made from jute weighing at least 280g/m2. The dimensions of the bags shall be 840x350mm and the top of each bag shall be hemmed. A tie string shall be attached 100mm below the top of the bag. Each bag shall be filled with a maximum of 25 litres of fresh concrete prior to sealing. The filled and sealed bags shall be placed by hand to the lines and levels indicated on the drawing HOB-11. Each row of bags shall be staggered in brick-wall fashion to provide a minimum wall thickness of 500mm.
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6.8 FORMWORK
The formwork shall be of timber or steel and must be sufficiently strong, impervious and resistant to the action of cement. The formwork shall be true to line and level and adequately supported by struts and shores in such a manner that there will be no deflection under the liquid and solid pressure exerted by the concrete. The faces of formwork shall be constructed so as to avoid all leakage of liquid from the concrete and any joints in the formwork must be flushed up so as to avoid any marking appearing on the finished work. All rubbish and loose materials shall be removed from the inside of the formwork before concreting. The face of the formwork in contact with the concrete shall be wetted with clean water or approved shutter oil immediately prior to concreting.
All formwork shall be struck without jarring the concrete or subjecting same to sudden shock. Before striking any formwork, the contractor shall satisfy himself that the concrete is sufficiently hardened to bear its own load and any other loads that may be placed upon it. No formwork is to be removed if in the opinion of the Supervising Engineer the concrete has not set sufficiently. Approval of the Supervising Engineer shall not relieve the Contractor of his liability to make good any concrete, which may be damaged by premature removal or collapse of formwork.
After removal of shuttering, the surface of all concrete shall be brought to a true surface and all defective portions of the face repaired, all cavities filled and any projections removed. In the event of parts of the concrete being honey-combed, such portions shall be cut out to a depth and shape required by the Supervising Engineer and made up with fine concrete of equal quality.
7. BILL OF QUANTITIES
This Bill of Quantities is for the supply only of the jetty components, DAP Berbera WFP warehouse (Incoterms 2010), on-site assembly and construction in Hobyo, Galmadug State, Republic of Somalia.
The quantities given in the following Schedule are approximate and shall be so regarded in accordance with the provisions of the general Conditions of Contract.
The general descriptions given in the Schedules are to identify the work covered by the respective items, but the exact nature and extent of the work is to be ascertained from the Drawings, Specifications and Conditions of Contract, as the case may be.
All measurements shall be taken net, except when otherwise specified, and shall be applicable to finished work only as completed, notwithstanding any trade custom to the contrary. To assist the supplier in assessing the items required, the original design taking-off sheets are included for reference.
The following abbreviations are used in this document:-
mm = millimetre m = metre Kg = Kilogramme t = Tonne (1000 Kg) m2 = Square metre m3 = Cubic metre Each = Number
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7.1 BOQ FOR DELIVERY PHASE
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BOLTS NUTS AND WASHERS
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- 29 - Rev [1] [Hobyo Fishing Jetty] [Scope of Works]
STEEL COMPONENTS – PILES
ITEM C A L C U L A T I O N Item Item Quantity Weight Surface of items Kg Area No m2 A.1 PILE TRUNK CHNG 0-10m HEA 300 SPECIFICATION S355 G11+M Steel to EN 10225 LENGTH 2500 mm PAINTED SURFACE ALL
220.75 3.52 6 A.2 PILE TRUNK CHNG 10-30m HEA 300 SPECIFICATION S355 G11+M Steel to EN 10225 LENGTH 3000 mm PAINTED SURFACE ALL
264.90 4.52 21 A.3 PILE PLATFORM HEA 300 SPECIFICATION S355 G11+M Steel to EN 10225 LENGTH 3500 mm PAINTED SURFACE ALL
309.05 5.80 18 A.4 PILE CAP PLATE 10mm plate 300x290 SPECIFICATION S355 G11+M steel to EN 10225
6.83 0.18 45 A.5 PILE CAP GUSSETS 10mm plate ½ 0.145x0.145 SPECIFICATION S355 G11+M steel to EN 10225
0.83 0.025 270 A.6 PILE BRACE GUSSET 10mm plate 120x180 SPECIFICATION S355 G11+M steel to EN 10225
1.69 0.04 36 A.7 PILE TOE CAP 10mm plate 100x290 SPECIFICATION S355 G11+M steel to EN 10225
2.28 0.06 45 A8 FIRST PILE BENT ANCHORS UC 100x50x8.5 SPECIFICATION S355 G11+M Steel to EN 10225 LENGTH 2300 mm PAINTED SURFACE ALL 23.50 0.90 6
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TAKING-OFF SHEETS
STEEL COMPONENTS – DECK SUPERSTRUCTURE
ITEM C A L C U L A T I O N Item Item Quantity Weight Surface of items Kg Area No m2 B.1 DECK LONGITUDINAL BEAM RHS EDGE BEAM IPE 270 SPECIFICATION S355 G11+M Steel to EN 10225 LENGTH 9,990 mm PAINTED SURFACE ALL 397.13 12.26 6
B.2 DECK LONGITUDINAL BEAM CENTRAL BEAM IPE 270 SPECIFICATION S355 G11+M Steel to EN 10225 LENGTH 9,990 mm PAINTED SURFACE ALL 400.66 12.26 18
B.3 DECK LONGITUDINAL BEAM LHS EDGE BEAM IPE 270 SPECIFICATION S355 G11+M Steel to EN 10225 LENGTH 9,990 mm PAINTED SURFACE ALL 397.13 12.26 6
B.4 DECK CROSS BRACING SPACER BEAM UC 100x50x8.5 SPECIFICATION S355 G11+M Steel to EN 10225 LENGTH 1560 mm PAINTED SURFACE ALL 16 0.61 120
B.5 PILE CROSS BRACING SPACER BEAM UC 100x50x8.5 SPECIFICATION S355 G11+M Steel to EN 10225 LENGTH 3000 mm PAINTED SURFACE ALL 30.6 1.17 18
B.6 DECK CROSS BEAM HEA 300 SPECIFICATION S355 G11+M Steel to EN 10225 LENGTH 6500 mm PAINTED SURFACE ALL 574.0 11.44 15
B.7 DECK COPE BEAM IPE 270 (Notched) SPECIFICATION S355 G11+M Steel to EN 10225 LENGTH 1560 mm PAINTED SURFACE ALL 56.32 1.67 13
- 31 - Rev [1] [Hobyo Fishing Jetty] [Scope of Works]
TAKING-OFF SHEETS
STEEL COMPONENTS – DECK SUPERSTRUCTURE
ITEM C A L C U L A T I O N Item Item Quantity Weight Surface of items Kg Area No m2 B.09 STEEL FLATS EDGE & CENTRAL BEAM FLAT 5x60 SPECIFICATION S355 G11+M Steel to EN 10225 LENGTH 9990 mm PAINTED SURFACE ALL 23.6 0.12/m 30
B.10 GUSSET PLATES ON IPE 270 PLATE 6mm SPECIFICATION S355 G11+M Steel to EN 10225 DIMENSIONS 249x64x6 PAINTED SURFACE ALL 0.75 0.03 360
B.11 GUSSET PLATES ON HEA 300 PLATE 6mm SPECIFICATION S355 G11+M Steel to EN 10225 LENGTH 260x145x6 PAINTED SURFACE ALL 1.79 0.08 240
B.12 ANGLE CONNECTIONS ON IPE 270 ANGLE 80X60X7 SPECIFICATION S355 G11+M Steel to EN 10225 LENGTH 100mm PAINTED SURFACE ALL 0.73 0.03 240
B.13 BOLTS NUTS & WASHERS M20 AT ANCHOR POINTS SPECIFICATION DIN 933 A4-80 to AISI 316L LENGTH 50mm PAINTED SURFACE NO 295 ------2,500 NUTS HEXAGONAL HEAD Estimate B.14 GALVANISED GRILL MESH 25x76 VERTICAL FLAT 60x4 SPECIFICATION S 235 JR UNI EN 10025 GALVANISING HOT DIP TO EN ISO 1461 33,762 ------390 m2 ANCHOR BOLTS AS SPECIFIED Kg
B.15 WELDS ALL SIZES SPECIFICATION FULL PENETRATION FILLET WELDS MIG WELDING
Weight of structural steel to be shipped, including fittings 38.0 Tons Weight of galvanized steel grating to be shipped 33.80 Tons
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7.2 BOQ FOR CONSTRUCTION PHASE
BILL OF QUANTITIES - MOBILISATION
Item D E S C R I P T I O N Unit Quantity A1 Mobilisation and demobilisation of contractor’s plant to Hobyo,
including office and other services, excavator, hydraulic chisel, Sum concrete mixer, scaffolding, compressor, air drill, generator, flood lights, potable water tanker, etc. -- A2 Stockpiling of construction materials, including aggregate, sand, water and cement. Sum
-- A3 Setting-out surveys, benchmarking, trial pits and other pre-
construction surveys. Sum
--
A4 Supply, run and maintain for 3 calendar months a quality control laboratory, including steel moulds for test cubes, cube crushing machine, slump test cone, curing tank, etc. Sum
-- A5 Supervision of works for 3 calendar months.
Sum
-- A6 Back-of-jetty post construction clean-up and disposal of material as directed. Sum
--
BILL OF QUANTITIES - PILING WORKS
Item D E S C R I P T I O N Unit Quantity B1 Drill in to bedrock and box-out 500x500 square sockets, 500- 700mm deep to receive pile sections and dispose of material as m3 5.60 directed by the Supervising Engineer.
B2 Pre-assemble jetty portals (cross beam bolted to 3 vertical piles
as indicated on the drawings) on flat ground ensuring that paint 15 coating is not damaged. Each
B3 Handle, pitch and suspend assembled portal from a scaffold
template along the lines and levels indicated, ensuring that each 15 pile is socketed to a depth of at least 500mm below the level of Each the bedrock. B4 Batch and place Grade 35 concrete in sockets during low tide events, incl pumping out any sand intruded inside the socket. m3 5.60
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BILL OF QUANTITIES - STEEL DECK
Item D E S C R I P T I O N Unit Quantity C1 Handle, place and bolt IPE270 beams for the formation of the deck and coping
beam as specified in the drawings, 24,840 Kg including cross bracing channels and expansion joints at both extremities, with lock nuts and PTFE gasket.
C2 Handle, place and anchor in position
galvanised grating using stainless anchor Kg 31,500 grips in AISI 316L over the jetty deck as indicated in the drawings. C3 Handle, place and bolt in position stainless steel railings along jetty trunk m 60 as indicated in the drawings.
BILL OF QUANTITIES - BERTHING & MOORING FIXTURES
Item D E S C R I P T I O N Unit Quantity D1 Handle and bolt in place Neoprene rubber wing fender along the indicated vertical HEA 300 piles, including all bolts, Each 9 washers and nuts as specified on the drawings.
D2 Bolt in place twin-head mooring
bollards. Each 4
D3 Bolt in place galvanized base plate for light
pole where indicated on the drawing, including 2 galvanized pole and solar light fixture. Each
D4 Handle and bolt in place manually- operated hoist in the position illustrated
on the drawings. 1 Each
D5 Supply and install solar-powered
navigation light, complete with dry gel 1 battery all as indicated in the drawings. Each
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BILL OF QUANTITIES – SHORE WORKS
Item D E S C R I P T I O N Unit Quantity E1 Supply and place Grade 30 concrete in jute bags for the formation of the wing walls to the approach causeway. m3 60.0
E2 Supply and place “plummed” Grade 25 concrete (size 5-50 kg) inside causeway m3 80.0 (50% concrete + 50% rock), including horizontal anchoring of first portal. E3 Supply and place Grade 35 concrete
paving, 120mm thick over causeway, m3 72.0 including construction joints at 5000 intervals. E4 Supply and place Grade 35 concrete for the formation of the wave wall. m3 49.0
E5 HYS in wave wall, including coring and Kg anchoring of vertical rebars on outer 836 face.
8. PAYMENT AND PAYMENT MILESTONES-FIRM AND FIX PRICE
This is firm and fixed price/lump sum contract. The contractor shall ascertain correctness and sufficiency of tenders since no variation will be accepted. The pricing documents, attached with this, is for information and to guide the preparation of bids and payment milestones. The contractor shall provide separate quotes for each project phase. Price shall include everything necessary to be provided and carried out for the full and complete execution of the service and is fully inclusive of but not limited to all personnel, crafts, equipment, taxes, insurance, premium, admin expenses, overheads and profit, and any other costs and charges not specifically detailed. The Contractor is also asked to provide time charges for personnel, equipment, and crafts proposed for the works. The time charges will be used for any additional works the employer may wish to carry out which are not specifically contained in this scope of works. The contractor is also advised that the time charges may not be applicable for delays attributable to contractor’s failure to carry out his responsibility with due care. The payments will be made to the Contractor upon achieving a pre-agreed project phase/milestones, WFP proposes the milestones and amount of payment for each project phase/milestone as follows:
DELIVERY MILESTONES
• Advance for steel structure manufacturing 25%, • Jetty structure components, equipment and electrical fixtures are ready for shipment. Payment against copy of a Bill of Lading and Insurance Policy document – 50% • Jetty structure components, equipment and electrical fixtures hand-over completed at the Employer’s warehouse in Berbera - 15% • Delivery and discharge in Hobyo completed – 10%
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CONSTRUCTION MILESTONES
• Mobilisation to the construction site - 20%, • Wave wall construction finalized, causeway walls are completed, access way paved in concrete, first pile bent is anchored – 40% • Piling works, jetty structure elements, and deck assembly are finalized, electrical fixtures, fittings, and equipment are installed. The Jetty construction is finalised – 40% WFP shall retain a maximum of 10% on every invoice or pay in full at its discretion and in accordance with the contract
9. DELIVERABLES
WFP expects the contractor to avail all requisite personnel, craft and equipment for successful completion of the service: The main deliverables are:
• The steel structural elements are manufactured, the equipment and electrical fittings are supplied as per the project design requirements, a copy of a Bill of Lading submitted to the Employer; • The shipment Insurance Policy document is submitted to the Employer; • The jetty steel structure and the equipment and electrical fittings are delivered to Berbera and a hand-over note issued and signed; • The jetty steel structure and the equipment and electrical fittings are discharged and stored in Hobyo. Steel structure elements are inspected, an illustrative report is submitted to the Employer; • Mobilization of sufficient and relevant personnel, crafts and equipment for successful and complete execution of the project is completed. Before the mobilisation the Contractor shall submit the Employer a method of the statement of construction works, project program, and site organization and works execution safety plans compliant with the highest available safety standards and guidance; • Daily progress reports are submitted in agreed format and timeline; • Highest standards of works safety with relevant multilateral occupational safety and health administration and guidance for specialised areas such as marine constructions adhered during the whole duration of the project; • The jetty construction works are finalised, inspection and final reports are submitted to the Employer.
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