Analysis of Situ Test Results of Earth Pressure and Pile Internal Force under Pile-Anchor Support in a Deep Foundation Pit in Xi’an

Abstract

At present, in deep foundation pit engineering, on the one hand, practice is ahead of theory, and on the other hand, theory can not correctly reflect the actual construction process and environmental effects. In order to further study the distribution and change law of earth pressure and internal force of pile body in deep foundation pit pile-anchor supporting system, field monitoring test of earth pressure and pile body reinforcement stress was carried out. The monitoring results show that before excavation, the distribution of earth pressure has a great relationship with the layering of the soil, and it is distributed in sections along the depth. Compared with the theoretical static earth pressure, the measured data of the upper depth is relatively small; after excavation, the overall earth pressure is distributed along the depth in a “z” shape under the non-limiting state. As the excavation progresses, the magnitude of the reduction of the earth pressure varies from place to place, and the magnitude of the decrease of the soil with better properties is not large; after the excavation, the stress and earth pressure of the pile reinforcement correspond to each other, and the distribution is also nonlinear. The existence of anchor tension has an obvious effect on improving the internal force of the pile. The selected earth pressure calculation methods have some discrepancies in the calculation of the earth pressure value of the project, and they need to be further improved. The research in this paper can provide reference and reference for the calculation of earth pressure and support design of pile-anchor supported foundation pit.