PILE LOAD TEST-abhishek.pptx

IS 2911

1. PILE FOUNDATIONS & Vertical PILE LOAD TEST IS 2911 PART IV

2. PILE FOUNDATION USES TO CARRY COMPRESSIVE LOAD If all the load is transferred to the pile tips End Bearing Piles If all the load is transferred to the soil along length of pile Pile Tip F riction Piles

3. PILE FOUNDATION USES TO RESIST UPLIFT LOAD Tension Pile: Mainly used for Transmission Towers, Offshore Platforms which are subjected to tension

4. TO CARRY UPLIFT AND HORIZONTAL LOAD Laterally Loaded Piles :Horizontal Load acts perpendicular to axis of pile Raker Piles: Driven at an angle Carry large horizontal load PILE FOUNDATION USES

5. PILE FOUNDATION T imber p ile : suitable for light loads C oncrete p ile : suitable for all loading conditions , most frequently used piles S teel Pile : used to carry very heavy loads U nder-reamed Pile : used in expansive soils

6. PILE FOUNDATION Mode of load transfer E nd B earing P ile : U ltimate L oad Carried by Pile=load carried by base F riction Pile : Ultimate Load Carried by Pile= load transferred by skin friction Combined End Bearing & Friction Pile : Ultimate Load Carried by Pile= load transferred by skin friction + load carried by the base

7. PILE FOUNDATION Method of installation d riven P ile : compacts the soil through which it is driven B ored Pile : best suited for clay soil

8. PILE FOUNDATION P recast & p restressed P ile : used in marine structures, Have large vertical load carrying capacity and bending moment capacity C ast in Situ P iles : most widely used piles

9. PILE FOUNDATION B ased on displacement of soil Displacement Piles: All driven piles are displacement piles as soil is displaced laterally while pile is driven Non-Displacement Piles : A ll bored piles are non displacement piles

10. PILE load capacity in compression Static Pile Load Formula Pile Load Test Pile D riving Formula Correlation from Standard P enetration T est D ata

11. PILE load capacity evaluation by static formula Static Pile Load Formula We can refer the following codes which give the guidelines for Design and Construction for various pile types. IS 2911 Part 1 Sec 1 -For Driven Cast in Situ piles IS 2911 Part 1 Sec 2 -For Bored Cast In Situ Piles IS 2911 Part 1 Sec 3 -For Driven Cast in Situ Piles Is 2911 Part 1 Sec 4 -For Precast Concrete Piles IS 2911 Part 2 -For Timber Piles IS 2911 Part 3-For Under reamed Piles IS 2911 Part 4-Method of Load Test on Piles

12. PILE load capacity B ored cast in situ concrete P iles (in Cohesive Soil)-IS 2911(Part 1 Sec 2 -2010) Ap -Cross Sectional Area of Pile Nc Bearing C apacity Factors Cp Average C ohesion at Pile T ip α Adhesion F actor at ith Layer Ci Cohesion at ith Layer As Surface Area of Pile at ith Layer This value is divided by a factor of Safety of 2.5 to arrive at the safe load carrying capacity.

13. PILE load test It is the only direct method for determining the allowable load on piles It is an in situ method and the most reliable one also. Serves as a check for the pile bearing capacity evaluated from static or dynamic approaches To determine the load-settlement behavior of a pile

14. PROCEDURE FOR MAINTAINED LOAD TEST AS PER IS 2911 PART 4 (2013)

15. T he allowable load on a single pile shall be lesser of the following for piles upto and including 600 mm diameter 2/3 rd of final load at which settlement attains a value of 12 mm. if nothing is specified then permissible settlement is 12 mm. if any permissible settlement is specified then load shall correspond to actual permissible total settlement. 50 % of final load at which total displacement equals to 10 percent of the pile diameter in case of uniform diameter piles and 7.5% of bulb diameter in case of under-reamed piles. Q1 Q2

16. T he allowable load on a single pile shall be lesser of the following for piles more than 600 mm diameter 2/3 rd of final load at which settlement attains a value of 18 mm or max of 2% of pile diameter whichever is less. 50 % of final load at which total displacement equals to 10 percent of the pile diameter in case of uniform diameter piles and 7.5% of bulb diameter in case of under-reamed piles.

17. DIGHA TEST PILE – KENTLEDGE ARRANGEMENT SAND BAGS OVER DECK BEAMS

18. DIGHA TEST PILE ARRANGEMENT

19. DECK BEAMS

20. LATERAL STABILITY OF BEAMS WITH UNRESTRAINED COMPRESSION FLANGES The allowable bending stress in compression F bc depends upon the yield stress of the steel as well as the lateral support condition of the beam. When the beam is adequately supported in the lateral direction at all points, the allowable stress may be taken equal to that in tension as given above that is F bc = 0.66 Fy . But where lateral supports exist at the ends only or at some distance apart along the length of the beam, the critical stress in lateral buckling may become less than the yield stress and the allowable stress correspondingly reduced

21. PROBLEM STATEMENT IN THE METHOD OF STATEMENT SUBMITTED BY THE TEST AGENCY FOR DESIGN OF BEAMS THE REDUCTION IN ALLOWABLE STRESS IN BENDING COMPRESSION WAS NOT CONSIDERED SINCE THE BEAM ARE NOT LATERALLY RESTRAINED SO REDUCE THE PERMISSIBLE STRESSES IN BENDING COMPRESSION AND INCREASE BEAM SIZE OR PROVIDE STIFFNERS TEST SET UP WAS COMPLETE SO ARRANGEMENT COULD NOT BE DISTURBED

22. PROBLEM REASON