Study on model test of the new O-cell load test method with two loading directions

Abstract

Aiming at the possible problems of the new O-cell load test method with two loading directions in engineering practice, the operability and feasibility of this new method is studied by using indoor model tests and finite element numerical simulations. According to the similar principle, three groups of the traditional static load test, the O-cell load test and the updated O-cell load test under the same working conditions are designed and poured to obtain the pile ultimate compressive bearing capacity for comparison. Strain gauges and optical fibers are also used to detect the strain of the outer surface of the pile and the soil layer around the pile. The research results show that based on the bearing capacity results of the traditional static load test, the results of the physical model under the updated O-cell load test are compared with the results under the O-cell load test. The deviation is reduced by 3.54%-7.34%. At the same time, based on the physical test, the finite element analysis shows that the longer the pile length, the greater the deviation reduction. When the pile length is twice the physical model test, the contrast deviation reduction value is 9.15 %-15.71%. The strain results in the physical test also reflect the mechanism of pile-soil interaction well, and there is also a deficiency that the position of the equilibrium point needs to be determined.