Abstract：The micro cast-in-place pile with steel tubes is one of the micro-piles, which is often used in the foundation reinforcement of buildings. Based on the static load test results of micro cast-in-place piles with steel tubes in a foundation reinforcement project in Jinshazhou, Baiyun District, Guangzhou City, a model for the interaction between steel tubes, core concrete, soil and rock is established by using the ABAQUS finite element software. The influences of the modulus of foundation rock, the ratio of depth to diameter of rock socket and the thickness of steel tube on the bearing capacity of the micro cast-in-place piles with steel tubes are discussed. The numerical simulation of static load tests shows that the resistance of pile tip is still the main part of bearing capacity for super-long piles with overlying soft soil. The bearing capacity of piles increases with the increase of the elastic modulus of bedrock, but the nonlinear relationship leads to a slower growth trend. The vertical bearing capacity of piles increases linearly with the increase of the thickness of steel tube wall. It has little effect on the vertical bearing capacity of piles.
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