Enhancing static load test of pipe pile composite foundation with innovative elastic cushioning technology

Pipe piles have been widely used in composite foundation treatment by virtue of the advantages of assembly line production, easy control of pile quality, fast construction, high bearing capacity of single pile and green environmental protection. By introducing elastic cushion in the static load test method of pipe pile composite foundation, and using theoretical analysis and field test to study the change rule of settlement, pile-soil stress ratio and pile top stress of pipe pile composite foundation with different cushion stiffness. It is concluded that it is feasible to replace the sand cushion layer recommended by the current specification with elastic cushion layer. The study shows that the elastic cushion method of static load test of pipe pile composite foundation is closer to the bearing state of real working condition. The elastic cushion has better pile-soil stress adjustment effect, which is more responsive to the stress adjustment effect of actual engineering cushion, and the elastic cushion provides an improved method for the static load test method of composite foundation.