Analysis On Force And Deformation Of Deep Foundation Pit Supporting Structure Under Traffic Loads

In recent years, the increasing number of urban road reconstruction projects and subway construction projects, and in which the environment is very complex:the underground pipelines, water pipelines, and other municipal facilities are buried in the original road, vehicle load driving around foundation pit. To ensure the construction of the pit is continued, but also to ensure the traffic keep working, so a problem for the safe construction appears. Study on force and deformation of deep foundation pit supporting structure under traffic loads has a vital theoretical and practical value on construction projects. This paper regards Jing-Sha fast-track excavation monitoring program in Zhengzhou City, as the background project, using the numerical simulation method to simulate the internal force and displacement variation of the retaining structure under the traffic loads. To summarize the monitoring data and research the force and deformation of foundation pit under the vehicle load. Main findings and conclusions are as follows:1) To simplify the model of vehicle load, as equivalent concentrated static load, half-sine wave load, moving load, and random load is available, can simulate the interaction between the vehicle and the pavement structure. In numerical simulation analysis, the law of the internal forces and deformation of supporting structure under centralized static load and half-wave sinusoidal is studied, and under the concentrated static loads, the internal force and deformation of supporting structure with the loading position are differences, reflected from the slope of foundation pit is more nearly in the loading position, caused by internal forces and deformation is greater. While the location of the loads over a certain distance, the effect of the plus a load on the supporting structure internal force and deformation can be negligible.2) In order to simulate the ripple effect of traffic load for the internal forces and deformation of the supporting structure, this paper simplified the traffic load for the half-sine wave load. The farther Half-sine wave loads away from the pit surrounding the location, the greater deformation and internal forces of the supporting structure. which is similar to the law caused by static loads. The half-wave sinusoidal load angular frequency have a certain impact on the retaining structure, the axial force of anchor decreases as the load angular frequency increases; retaining pile horizontal displacement increases with the increase of load angular frequency; the internal force of support structure decreases as the load angular frequency increases.3) In this paper, analysis of monitoring data of a project example, the results show that the distance of the vehicle load around foundation away from the foundation pit supporting structure location has an influence on the internal force and horizontal displacement, the closer vehicle load location, the greater the internal force and horizontal displacement of supporting structure. Finally, Comparative analysis of the results of numerical simulation and monitoring data, the results show that the internal force and displacement variation of the foundation pit supporting structure is consistent, to verify the reliability of the numerical simulation results.