Research On The Support By Anchor-Pile And Soil-Nail Wall Of Deep Foundation Pit

This paper is set in the deep foundation pit of handan city, researchs into the force and deformation of solum and structural support while excavating of deep foundation pit step by step after refering to the relevant research results in deep excavation engineering, It has adopted the combination of three methods:field monitoring,theoretieal researeh,numerical simulation,and.The main content of this paper and the conclusion are as follows.(1)The Foundation Engineering Design was introduced with emphasis on the economical and applicable foundation-for the support method combinating soil nail wall with reinforcement concrete piles. And this kind of design needs to consider environmental effects deliberately.(2)We monitor the whole process of construction on the foundation, including surface settlement, lateral displacement, soil pressure, pile bending moment changes in side slope, and so on. Then analy the monitoring data, Show that the foundation displacement, force influenced greatly by the excavation steps, and these data and monitoring space has a great relationship.(3)The excavation process was simulated analysis, including displacement, foundation stability, plastic zone, the force of supporting structure. Show the force of structure, lateral displacement, and the settlement of foundation has a strong space-time effect, the maximum surface settlement did not occur in the pit edge, but a certain distance from the edge. The largest lateral displacement is on the edge of the pit and a larger value on the pile head. Internal forces of piles are larger in one direction, others are almost negligible in both directions. During the spporting of the soil nailed wall, shoting concrete surface may increase the safety by 30%. In the stage of the support by piles, anchor bolts can increase the safety factor up to 50%;The increasing safety rates of the foundation pit will be not obvious when the radius of piles increased a certain value.(4)The deep foundation pit is a comprehensive project. Designing theory, monitoring results and numerical simulation are in despite of differences, but are not isolated, designing theories can be used for monitoring and the numerical simulation, meanwhile,monitoring and numerical simulation results can be used for designing theory. And monitoring and numerical simulation results were particularly important for dynamic design.This paper is a research on foundation combinating the engineering case, can provid references for similar excavation and support of pit.