地铁车站基坑施工引起的周边建筑物沉降分析

Settlement Analysis of Surrounding Buildings Caused by Foundation Pit Construction of Subway Station

以某临近既有建筑物的地铁车站工程为研究对象,通过对地铁车站围护结构施工过程中建筑物的沉降监测,获得了地下连续墙围护结构施工过程中建筑物的沉降规律。研究表明,地铁车站地下连续墙成槽浇筑对建筑物沉降影响显著,占基坑施工引起的总沉降值的39%~65%,大于土体开挖期间引起的沉降量。在此阶段地连墙施工时,应重视建筑物的安全。在既有建筑物和2#风道间增设三轴高压旋喷用作隔离,能有效的限制风道地连墙施工、基坑降水与土体开挖引起的建筑物沉降,从而减少地铁车站施工对周边建筑物的影响。并基于研究结果,分析了地下连续墙施工和三轴高压旋喷隔离桩施工造成沉降的原因。

Taking a subway station project adjacent to an existing building as the research object,through the settlement monitoring of buildings during the construction of subway station envelope,the settlement rule of buildings during the construction of underground diaphragm wall envelope is obtained.The research shows that the grooving and pouring of underground diaphragm wall in subway station has a significant impact on the settlement of buildings,accounting for 39%-65%of the total settlement caused by foundation pit construction,which is greater than the settlement caused by soil excavation.During the construction of diaphragm wall at this stage,attention should be paid to the safety of buildings.Triaxial high-pressure jet grouting is added between existing buildings and 2#air duct for isolation,which can effectively limit the building settlement caused by the construction of air duct diaphragm wall,foundation pit dewatering and soil excavation,so as to reduce the impact of subway station construction on surrounding buildings.Based on the research results,the causes of settlement caused by diaphragm wall construction and triaxial high-pressure jet grouting isolation pile construction are analyzed.