深基坑工程支护桩侵限切除及加固处理研究

Study on the invasion limit excision and support piles reinforcement in deep foundation pit

咬合桩在深基坑工程中已得到广泛应用,受到地质条件、施工组织、操作能力等因素的影响,支护桩侵限事故经常发生。本文通过纤维模型有限元计算程序,计算了侵限处理前、后支护桩的受弯承载力,同时结合桩身深层水平位移监测反分析结果,论证了采用粘钢加固方法处理侵限支护桩的可行性。利用基坑的空间效应,采用分序跳桩施工对侵限支护桩进行切割和加固,基坑处于安全稳定状态;对加固处理后的监测成果及桩身受力情况进行分析,结果显示截面承受的弯矩值小于截面受弯承载力。本项目加固施工取得了良好的效果,有效解决了基坑支护桩侵限的处理难题,可为同类项目提供借鉴。

The interlocking pile has been widely used in deep foundation pit engineering,and accidents of support piles invasion often occur due to factors such as geological conditions,construction organization,and operational ability.This article uses a fiber model finite element calculation program to calculate the bending bearing capacity of support piles before and after the invasion treatment.At the same time,combined with the back analysis results of the deep horizontal displacement monitoring of the pile,it is demonstrated that the use of adhesive steel reinforcement method to treat the invasion support piles is feasible.Using the spatial effect of the foundation pit,the step⁃by⁃step pile jumping construction is used to cut and reinforce the invasion support piles,and the foundation pit is in a safe and stable state.Analysis of the monitoring results after reinforcement treatment and bending condition of pile body shows that the bending moment value borne by the section is less than the bending bearing capacity of the section.The reinforcement construction of this project has achieved good results,effectively solving the invasion limit problem of the support piles in foundation pits,which can provide reference for similar projects.