Determination of 1200 mm working piles deformation parameters, using test of smaller diameter pile for the piled raft foundation of Capital Fort project

摘要

Capital Fort mixed used development comprises a 30-storey, 126 m high office tower and an 8-storey, 35 m high, L-shaped office building, unified with a two storey deep basement. Foundation structure is a raft with a variable thickness under both buildings and bored piles under the high-rise. Deformation and strength characteristics of the soil, received from the geological survey, are used for a preliminary analysis of the combined piled raft foundation. Deformation modules are defined using the results from the standard penetration test. Single pile test is performed for determination of the geotechnical parameters used for refinement of soil analytical model. Working piles are 28 m deep and have a diameter of 1200 mm. Pile with smaller diameter (600 mm) is used for the test. The depth of the tested pile is the same as the working ones. Casing and concrete grade C25/30 are used for the construction of the pile. Anchoring system comprises four working piles. Hydraulic loading system with 8000 kN capacity is used. Measuring system monitors the settlement of the pile head and comprises three dial gauges with 0.01 mm precision, placed at 120 degrees in plan. The pile is loaded in 11 steps of 700 kN each, up to 7700 kN, realizing 30.5 mm settlement. Results from the test and a comparison with the analytical results from the preliminary adopted parameters are presented in the article.