基于应变控制的隧道盾构施工引起的砌体建筑损伤预测分析

Monitoring and Analysis of Ground Settlement of Tunnels Constructed by Shield Method based on Strain Control

基于极限拉应变法对盾构机切削已有建筑物复合地基水泥土桩引起的砌体结构的损伤程度进行分析。通过对城市地铁盾构下穿施工过程中,场地地表沉降进行计算,进而将场地建筑变形分为'下凹'和'上凸'分别计算建筑物的拉应变。通过叠加分析水平拉应变与弯曲应变和剪切应变,评价建筑的整体损伤情况,并与传统根据实测建筑变形进行建筑安全分析进行对比。分析结果表明,采用极限拉应变法对砌体结构进行分析时,可以更加直接和详细地分析建筑局部拉应变的数值,更好地给出建筑物的损伤程度,更有利于设计和施工的参考。通过与现场实测数据的对比分析,认为采用极限拉应变法分析盾构隧道导致的砌体损伤问题是有效的。研究成果对城市盾构隧道施工导致的砌体房屋损伤评价有指导意义。

Based on the ultimate tension strain method,the damage degree of masonry structure caused by shield machine cutting the soil-cement pile on the composite foundation of existing buildings is analyzed.Through the calculation of the ground subsidence during the underground crossing of city subway shield,the deformation of the building is divided into'depression'and'uplift'to calculate the tensile strain of the building.Through superposition analysis of horizontal tensile strain,bending strain and shear strain,the overall damage situation of the building is evaluated and compared with the traditional construction safety analysis based on measured deformation.The analysis results show that the analysis of masonry structure by ultimate tensile strain method can be more direct and detailed to analyze the value of local tensile strain of building,give the damage degree of building better,and be more beneficial to the reference of design and construction.By comparing with the field measured data,it is considered that it is effective to analyze the masonry damage caused by shield tunnel by limiting tensile strain.The research results are of guiding significance for damage assessment of masonry houses caused by shield tunnel construction.