Comparison between Eurocode 7 and British Standard in pile design under mixed ground condition

• Main Author: Feng, Jing
• Other Authors: Teh Cee Ing
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Civil engineering::Geotechnical
• Online Access: http://hdl.handle.net/10356/53866
• Institution: Nanyang Technological University

Pile foundation is extensively used in Singapore construction projects. Pile foundation axial capacity is designed based on the soil property, namely clayey/ silty soil, sandy soil and rock. Pile axial capacity includes two aspects: base resistance (Qb) and shaft resistance (Qs). Each aspect has several approaches for estimating its value. Among in-situ tests, Standard Penetration Test (SPT) and Cone Penetration Test (CPT) are usually the only available methods. All other soil properties are correlated with those two tests. Thus, Standard Penetration Test and Cone Penetration Test profile together with pile loading test results were used in the project for case study. Eurocode 7 introduced several partial factors with regards to the action loads, installation methods and soil parameters. Major differences exist between Eurocode 7 and British Standard in the procedure to obtain designed axial capacity. Additionally, Eurocode 7 itself suggests 4 combinations of partial factors, which can generate different results under same calculation model. The results differ from each combinations and the design should be satisfy for every combination. In order to draw a conclusion from the design differences between Eurocode 7 and British Standard, several case studies were conducted using results from pile load tests and its corresponding in-situ test soil profiles, which measured the ultimate load capacity of the pile and the soil conditions. Pile allowable capacity estimated from in situ test using Eurocode 7 is compared with the ultimate pile capacity from pile load tests results. The results showed that Eurocode 7 generated more economical pile design when compare with British Standard in mixed ground condition using soil profile from in situ tests. It showed that for SPT profile, the designed pile resistance was even less conservative; while for CPT profile, the designed pile resistance was similar to British Standard.