DESIGN OF PILE FOUNDATION FORA MAJOR BRIDGE BATCH MEMBERS: • SELVARASAN.P • SIVARAJ.R • VIGNESH.B • VIMALRAJAN.A (50408103040) (50408103044) (50408103054) (50408103058) GUIDED BY: Prof. Dr.V.BALAKRISHNAN. Department of Civil Engineering. Conclusion Reference . Classifications of piles by material. Design of pile (for piles acting individually and group). Impact factor for live load. Efficiency of pile group. Reinforcement details of pile cap.CONTENTS 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 12) 13) 14) 15) Pile foundation. Shear force calculation. Reinforcement details of a pile. Design of pile cap. Functions of pile cap Load calculation(both Dead load and live load). Moment calculation. Types of piles. They are. located at certain depth below ground surface. Pile foundations are the part of a structure used to carry and transfer the load of the structure to the bearing ground. Pile foundation. The main components of the foundation are the pile cap and the piles. There are two types of piles.1. Types of Piles Types of piles based on the mechanism of load transfer. Bearing piles Friction piles . 2. cast in.3. Classification of piles by material Timber piles. such as jetties or bridge piers. Piles are a convenient method of foundation for works over water. In this project. lateral and uplift load Piles can also be used in normal ground conditions to resist horizontal loads.situ concrete piles are used. . Concrete piles. Steel piles.Functions of piles To transmit a foundation load to a firm ground To resist vertical. 4. 327 m3 Total volume = 891. Load from wearing course Load from wearing course is 1237.5 kN Load from pier Average solid rectangular area = 640.500 kN.5.000m3 Combined semi-circular area (cut water) = 251.175 kN . Load calculation (Dead load) Load from Box girder Total area of box girder = 7.4 m2 Self weight of the box girder Self weight of the box girder is 18.327 m3 Self weight of pier is 22283. 43 kN Total load on pile cap Total load on pile cap = 42081 kN .81) = 686. Total dead load is 42021 kN.8 percent for spans more than 45m. Impact factor of live load for bridge = 60.Total dead load = Self weight of box girder + load due to weathering coarse + Self weight of pier. Load calculation (Live Load – Tracked vehicle) Max Live load = (70 x 9. curve for reinforced concrete bridges denotes 8.7 KN 6. Impact factor for live load From graph. B.00 kNm.67 m Moment = Force x Distance Moment on pier due to water current = 550. Shear force due to Impact factor of live load Maximum shear force is occurs in the supports of the girder.89 kN Mean velocity at distance = 5. B. Moment calculation Max.215 KN. F = kAV2 = 96.M. Max. at mid span = 1510.75 kNm.55 m2 k = 35. 8.7. . Occurs when the load is at mid span. Moment on pier due to water current in lateral direction Projected Area of pier = 70.M. co-efficient of pier with semi circular cut water. Shear force at Supports = 30. 9. Spacing between two piles S = 4.5m To find the number of piles: Qug = n c Л d L 108402. Design of a pile Cohesive factor.5m.37 m2 Qug = 106028.75 = n (50 x Л x 1.5 x 23) n = 15 For piles acting individually Qug = n x Qup Qug = 15 x (c x Ap) Where. c = 50 A = ЛDL = 141. Diameter of each pile is (hp) 1.75 kN . c = 50 kN/m2 Adopted length of pile = 30m. 22 mm2 Diameter of core. 10. Asc = 10799.5 m2 Qug = 198375 kN Ultimate load bearing capacity of group of piles. Ak = 1364334 mm2 .Check for group action For group action of piles. Qug = 4 BpcLpc + Apc c Nc For clay. Nc = 9 Apc = Lpc x Bpc = 287. Dk = 1318 mm Area of core. Reinforcement details of a pile Diameter of pile = 1500mm Pitch = 50mm Clear cover to longitudinal bars = 75mm (min. cover = 40mm) Area of longitudinal steel. Qug = 198375 kN Hence the design of pile foundation for the bridge is safe. 2 kN Therefore a pile can carry the ultimate load from above structures. Ac = 1756346.4 fck Ac + 0.648 mm2 Ultimate load carrying capacity for the pile. of column corresponding to centre of helical bars.659 mm Volume of helix per pitch length = 822475.67 fy Asc) = 17906.261 kN 7166.837 mm3 Volume of core per pitch length = Ak x P = 68216700 mm3 . of helical rod dh = 1302 mm Gross area of pile. Consider one pitch length of the column P = 50 mm Length of helix per pitch length = √ (Л x dh) 2 + P2 = 4090.261 kN < 17906. Pu Pu = 1.2 kN Load for each pile = 7166. Ag= 1767145. dh dh = Dk – Dia.Dia.05(0.868 mm2 Area of Concrete. 0121 This value should be ≥ 0. .Ratio of volume of helical steel to volume of core = Volume of helix per pitch length / Volume of core per pitch length = 0.005 Hence the provision of helical reinforcement is satisfactory.17 Therefore provide 195 mm spacing between each longitudinal bars. Spacing of longitudinal bars Diameter of core.619 Spacing of longitudinal 32 mm dia. rods = 197.0121 ≥ 0.36 [(Ag / Ak) – 1](fck/fy) ≥ 0.005 0. Dk = 1318 mm Л x Dk = 4140. 2m Self weight of pile cap = 30187.9 % 12.500 kN Total load including pile cap = 72268.5 kN Factored load = 108402. Efficiency of pile group By using Converse Labarre formulae. Design of pile cap Choosing depth of the pile cap: hpc = 1/3 (8hp + 600) mm for hp ≥550 mm hpc = 4200 mm Therefore depth or thickness of the pile cap is 4.709 Therefore efficiency of group of piles = 70.75 kN .11. we can find the efficiency of pile group ηg = 1 – Ө/90 {[ (n-1)m + (m-1)n] / mn} Ө = tan-1(d/s) ηg = 0. Area of steel required.45 kN. Ast = 0.12 % x b x d = 5040 mm2 Provide 32 mm diameter bars Spacing = ast / Ast x 1000 = 159 mm Ast (Provided) =196237mm2 Ast (Provided) > Ast (Required) Due to the larger depth of the pile cap.13. provide 2 legged stirrups. As = (PL) / 4(0. . H = PL/4d = 29036.87 fy) d As = 80422 mm2 Minimum reinforcement. Reinforcement details of pile cap To find area of steel by Truss action. Hence the provided reinforcement for pile cap is safe. CONCLUSION This project has given opportunity to understand the basic principles of pile foundation design.1979. Part 1 – concrete piles. section 2 – Bored cast in situ piles. We have learnt the application of AUTOCAD during the course of this project. In the project pile and pile cap have been designed with reinforcement details During the course of the project we have gained knowledge about designing of pile cap and loading criteria. The pile foundation is designed as per IS 2911. . Indian Standards referred IS 456:2000 . Punmia. Design of Pile Foundation by Satyendra mittal. Tamil Nadu Highways Manual. Soil mechanics and Foundations by B. IS 2911.1979.code of practice for reinforced concrete. Part 1 – concrete piles / section 2 – Bored cast-in-situ piles.Varghese. Limit State Design of Reinforced Concrete by P. Ramamrutham. Ponnusamy.C. Indian Road Congress 6 -2000. Standard Specifications for Bridges. .C.References Books referred Bridge Engineering by S. Design of reinforced concrete structures by S. THANK YOU… .