Influence of pile installation and of pile test procedure on the test load results of Atlas pile ― A case study

摘要

Installation details for test and reaction piles have an influence on the initial soil stress condition around the test pile. Shaft capacity and skin friction in some cases is the major contributor to the total pile capacity and can directly be influenced by pile installation and pile test procedure. Inter-distance between test pile and reaction piles are usually taken in consideration in order to avoid mutual interaction. As a key element of a high speed rail project, 7km long, 10m wide, 450mm deep reinforced concrete piled slab foundation over the Thames Marshes needed to be investigated. For this purpose, three instrumented Atlas piles with different lengths were tested vertically both statically and cyclically. Four CFA anchor piles were acting as reaction piles for each test pile, two of which where shared between every sequent test piles. The results showed the interaction of the anchor piles with the test pile and showed also some test sequence influence. Strain gauges readings showed an uplifting force on the test pile induced by the utilized anchor piles even when there was zero load applied on the pile head.