Centrifuge model test and numerical analysis on steel pipe sheet piles reinforcement method

Steel pipe sheet pile (SPSP) reinforcing method for existing caisson foundation in water, which involves driving SPSP around the caisson foundation and then connecting the SPSP to the caisson at the top, is proposed. The practicability of applying this method and the reinforcement mechanism of SPSP reinforced caisson foundation system is investigated by conducting three-dimensional elasto-plastic finite element analysis. In the simulation, to propose more effective and reasonable design / construction method, the following factors that affect the effectiveness of SPSP reinforcement are considered: 1) connection condition of the caisson to SPSP reinforcement; 2) pile length. Based on the results of analysis, the authors try to estimate the SPSP reinforcement effect and reveal the mechanism which the lateral bearing capacity of reinforced foundation system is increasing.