支护桩危险点的判定方法研究  

Research on Judgment Method of Dangerous Point of Supporting Pile

作　　者：何钦 张记峰 丘北刘 He Qin;Zhang Jifeng;Qiu Beiliu(Guangdong Construction Engineering Quality&Safety Testing Head Station Co.,Ltd.Guangzhou 510500,China)

机构地区：[1]广东省建设工程质量安全检测总站有限公司,广州510500

出　　处：《广东土木与建筑》2020年第12期10-13,共4页Guangdong Architecture Civil Engineering

摘　　要：基坑监测中,为及时掌握支护桩使用期间的安全状态,一般采用预埋测斜管的方式对支护桩进行水平位移监测。根据桩身水平位移的变化可以推断出桩体的应力状态,并对桩体的安全性进行评估。根据现有规范《建筑基坑工程监测技术标准:GB 50497-2019》的规定,通常认为水平位移最大值处为支护桩危险点(应力状态最危险的点);而现有工程案例表明,实际工程中时而会遇到水平位移最大点并非断桩位置的情况。本文先利用有限元数值分析方法对该情况进行了模拟和分析,继而提出了一种根据桩身分段中最大相对位移为基准,判别桩体危险点的方法。数值计算结果表明,该方法在桩体测斜曲线不存在明显激凸变形点时,可辅助寻找桩体的应力最大点,以保证实际工程中能对桩体的实际危险点进行及时的补充支护。In foundation pit monitoring,in order to timely grasp the safety status of the supporting piles during use,the horizontal displacement monitoring of the supporting piles is generally carried out by means of embedded inclination pipes.According to the change of the horizontal displacement of the pile,the stress state of the pile can be inferred,and the safety of the pile can be evaluated.According to the existing specifications Technical standards for monitoring of building excavation engineering:GB 50497-2019,it is generally considered that the maximum horizontal displacement is the dangerous point of the supporting pile(the most dangerous point in the stress state);and the existing engineering cases show that the actual engineering will sometimes encounter horizontal.The point of maximum displacement is not the case of the broken pile position.This article first uses finite element numerical analysis method to simulate and analyze the situation,and then proposes a method to identify the dangerous point of the pile based on the maximum relative displacement in the pile section.Numerical calculation results show that this method can assist in finding the maximum stress point of the pile when there is no obvious bulge deformation point in the pile inclination curve,so as to ensure timely supplementary support for the actual dangerous point of the pile in the actual project.

关 键 词：支护桩 挠度分析 有限元分析 危险点判定 相对位移法 

分 类 号：TU198.2[建筑科学—建筑理论]