JSS Mahavidyapeetha Sri Jayachamarajendra College Of Engineering Mysuru – 570 006 HIGHWAY ENGINEERING DESIGN DATA HAND BOOK (Geometric Design and Pavement Design) Compiled By Dr. P. Nanjundaswamy Professor of Civil Engineering DEPARTMENT OF CIVIL ENGINEERING 2015 CONTENTS Page No. 1 GEOMETRIC DESIGN STANDARDS FOR NON-URBAN HIGHWAYS 1 – 9 1.1. Classification of Non-Urban Roads 1 1.2. Terrain Classification 1 1.3. Design Speed 1 1.4. Cross Section Elements 2 1.4.1 Cross Slope or Camber 2 1.4.2 Width of Pavement or Carriageway 2 1.4.3 Width of Roadway or Formation 2 1.4.4 Right of Way 3 1.5. Sight Distance 3 1.5.1 Stopping Sight Distance (SSD) 3 1.5.2 Overtaking Sight Distance (OSD) 3 1.6. Horizontal Alignment 4 1.6.1 Superelevation 4 1.6.2 Widening of Pavement on Horizontal Curves 6 1.6.3 Horizontal Transition Curves 7 1.6.4 Set-back Distance on Horizontal Curves 8 1.7. Vertical Alignment 8 1.7.1 Gradient 8 1.7.2 Length of Summit Curve 9 1.7.3 Length of Valley Curve 9 2 DESIGN OF FLEXIBLE PAVEMENTS 10 – 18 2.1 Design Traffic 10 2.2 Traffic growth rate 10 2.3 Design Life 10 2.4 Vehicle Damage Factor 11 2.5 Distribution of Commercial traffic over the carriageway 11 2.6 Design Criteria 12 2.7 Design Criteria 12 2.8 Design Charts and Catalogue 13 2.9 Pavement Composition 18 2.10 Final Remarks 18 3 ANALYSIS AND DESIGN OF RIGID PAVEMENTS 19 – 34 3.1 Modulus of Subgrade Reaction 19 3.2 Radius of Relative Stiffness 19 3.3 Equivalent Radius of Resisting Section 19 3.4 Critical Load Positions 20 3.5 Stresses and Deflections due to Wheel Load 20 3.5.1 Corner Loading 20 3.5.2 Interior Loading 21 3.5.3 Edge Loading 21 3.5.4 Dual Tires 22 3.6 Temperature Stresses 23 3.6.1 Warping Stresses (Westergaard Analysis) 23 3.6.2 Frictional Stresses 24 3.7 IRC Recommendations for Design of Plain Jointed Rigid 25 3.7.1 Legal Axle Load Limits 25 3.7.2 Load Safety Factors 25 3.7.3 Tyre Pressure 25 3.7.4 Design Period 25 3.7.5 Design Traffic 25 3.7.6 Characteristics of Sub-grade 26 3.7.7 Characteristics of Concrete 27 3.7.8 Fatigue Behaviour of Cement Concrete 27 3.7.9 Stress Computations 28 3.7.10 Temperature Differential 28 3.7.11 Recommended Design Procedure for Slab Thickness 28 3.7.12 Design of Joints 29 REFERENCES 1. GEOMETRIC DESIGN STANDARDS FOR NON-URBAN HIGHWAYS (IRC: 73-1980) 1.1 CLASSIFICATION OF NON-URBAN ROADS Non-urban roads in India are classified into following five categories based on location and function according to Nagpur road plan: National Highways (NH) State Highways (SH) Major District Roads (MDR) Other District Roads (ODR) Village Roads (VR) Present system follows modified classification system as per third 20-year road development plan. The roads are now classified into following three classes, for the purpose of transport planning, functional identification, earmarking administrative jurisdictions and assigning priorities on a road network: Primary system o Expressways and National Highways (NH) Secondary system o State Highways (SH) and Major District Roads (MDR) Tertiary system (Rural Roads) o Other District Roads (ODR) and Village Roads (VR) 1.2 TERRAIN CLASSIFICATION Table 1.1 Classification of terrains Terrain Classification Cross slope of the country (%) Plain 0 – 10 Rolling 10 – 25 Mountainous 25 – 60 Steep > 60 1.3 DESIGN SPEED Table 1.2 Design Speeds on Non-urban Roads Design Speed (km/h) Road Plain Rolling Mountainous Steep Classification Ruling Min Ruling Min Ruling Min Ruling Min Expressways 120 100 100 80 80 60 80 60 NH and SH 100 80 80 65 50 40 40 30 MDR 80 65 65 50 40 30 30 20 ODR 65 50 50 40 30 25 25 20 VR 50 40 40 35 25 20 25 20 1 1.4 CROSS SECTION ELEMENTS 1.4.1 Cross Slope or Camber Table 1.3 Recommended values of camber for different types of road surfaces Sl Range of Camber in areas of Types of Road Surface No Heavy rainfall Light rainfall 1 Cement concrete and high type bituminous surface 1 in 50 (2.0%) 1 in 60 (1.7%) 2 Thin bituminous surface 1 in 40 (2.5%) 1 in 50 (2.0%) 3 Water bound macadam and gravel pavement 1 in 33 (3.0%) 1 in 40 (2.5%) 4 Earth Road 1 in 25 (4.0%) 1 in 33 (3.0%) 1.4.2 Width of Pavement or Carriageway Table 1.4 Recommended values for width of carriageway Sl Class of Road Width of Carriageway (m) No 1 Single lane 3.75 2 Two lanes, without raised kerbs 7.0 3 Two lanes, with raised kerbs 7.5 4 Intermediate carriageway (except on important roads) 5.5 5 Multi-lane pavements 3.5 m per lane Notes: The lane width of Expressways is 3.75 m in plain and rolling terrains and 3.5 m in mountainous terrian The width of single lane for village roads may be decreased to 3.0 m On urban roads without kerbs the single lane width may be decreased to 3.5 m and in access roads to residential areas to 3.0 m The minimum width recommended for kerbed urban road is 5.5 m 1.4.3 Width of Roadway or Formation Table 1.5 Recommended values for width of roadway of various classes of roads Roadway width (m) Sl Mountainous Road Classification Plain & Rolling No & Steep terrain terrain National & State Highways 1 a. Single Lane 12.0 6.25 b. Two Lane 12.0 8.80 Major District Roads 2 a. Single Lane 9.0 4.75 b. Two Lane 9.0 --- Other District Roads 3 a. Single Lane 7.5 4.75 b. Two Lane 9.0 --- 4 Village Roads – single lane 7.5 4.0 2 1.4.4 Right of Way Table 1.6 Recommended land width for different classes of non-urban roads Mountainous & Plain & rolling terrain steep terrain Sl Road Classification Open Built-up No Open areas Built-up areas areas areas Normal Range Normal Range Normal Normal 1 Expressways 90 - - - 60/30 2 National & State Highways 45 30-60 30 30-60 24 20 3 Major District Roads 25 25-30 20 15-25 18 15 4 Other District Roads 15 15-25 15 15-20 15 12 5 Village Roads 12 12-18 10 10-15 9 9 1.5 SIGHT DISTANCE 1.5.1 Stopping Sight Distance (SSD) SSD = Lag distance + Braking distance = + (1.1) 2( ± 0.01) = Design speed (m/s) = Reaction time of driver (s) (2.5 seconds as per IRC guidelines) = Design longitudinal friction coefficient (Refer Table 1.7) = Acceleration due to gravity = 9.8 m/s2 = Gradient of road (%) (+ for ascending and – for descending) Table 1.7 Recommended longitudinal friction coefficient for providing SSD Speed (km/h) 20-30 40 50 60 65 80 ≥100 Longitudinal friction coefficient 0.40 0.38 0.37 0.36 0.36 0.35 0.35 Table 1.8 Recommended Stopping Sight Distance for different speeds Speed (km/h) 20 25 30 40 50 60 65 80 100 SSD (m) 20 25 30 45 60 80 90 120 180 1.5.2 Overtaking Sight Distance (OSD) = + + (1.2a) = + ( + 2) + (1.2b) ∗ ∗ = ( − 16) (As per IRC guidelines) (1.2c) ∗ = (0.2 + 6) (As per IRC guidelines) (1.2d) = 4 ⁄ (1.2e) 3 = Design speed or Speed of overtaking vehicle (m/s) = Speed of overtaken vehicle (m/s) = Reaction time of driver (s) (2.0 seconds as per IRC guidelines) = Time taken for overtaking operation (s) = The minimum spacing between vehicles (m) ∗ = Design speed or Speed of overtaking vehicle (km/h) ∗ = Speed of overtaken vehicle (km/h) = Average acceleration during overtaking (m/s2) Table 1.9 Maximum overtaking acceleration at different speeds Speed (km/h) 25 30 40 50 65 80 100 Max (kmph/s) 5.00 4.80 4.45 4.00 3.28 2.56 1.92 overtaking Acc (m/s2) 1.41 1.30 1.24 1.11 0.92 0.72 0.53 Table 1.10 Overtaking Sight Distance on two-lane highways for different speeds Speed (km/h) 40 50 60 65 80 100 SSD (m) 165 235 300 340 470 640 Note: = + for one-way roads = + + for two-way roads Intermediate Sight Distance (ISD) = 2 SSD Head Light Distance (HSD) = SSD 1.6 HORIZONTAL ALIGNMENT 1.6.1 Superelevation (e) + = (1.3) = Rate of superelevation = Design value of transverse or lateral friction coefficient (0.15 as per IRC guidelines) = Design speed vehicle (m/s) = Radius of the horizontal curve (m) = Acceleration due to gravity = 9.8 m/s2 Maximum Superelevation In order to account for mixed traffic conditions in India, IRC has defined the maximum limit of superelevation () as given in Table 1.11 Table 1.11 Recommended maximum limit of superelevation 7 % - Plain and rolling terrains and in snow bound areas 10 % - Hill roads not bound by snow 4 % - Urban road stretches with frequent intersections 4 Minimum Superelevation From drainage considerations it is necessary to have a minimum cross slope to drain off the surface water. If the design superelevation works out to be less than the camber of the road surface, then the minimum superelevation to be provided on horizontal curve may be limited to the camber of the surface.