SMW工法中型钢起拔对土体变形的影响研究

Effects of steel sheet pile extraction on ground deformation in SMW engineering method

为研究SMW工法型钢起拔过程中不同因素对周边土体变形的影响,基于南京某电缆隧道工程SMW工法型钢起拔工程实例,对拔除型钢后的基坑周边土体变形进行了监测,采用ABAQUS有限元软件进行数值模拟,将地表沉降及深层水平位移监测数据与模拟结果进行对比,验证了数值模拟的合理性,对不同弹性模量以及拔桩顺序下周边的地表沉降规律进行了分析。研究结果表明:水泥土弹性模量不超过600 MPa时,水泥土弹性模量每增加100 MPa,地表平均累计沉降相应的会减小,减小幅度在16.2%~19.5%,增加弹性模量能有效减少距钢板桩6 m内的地表沉降;不同的拔桩顺序形成的地表沉降差值不超过0.65 mm。

In order to study the effect of different factors on the deformation of surrounding soil during the process of pile excavation,based on the numerical simulation of ABAQUS finite element software,the deformation of the soil around the foundation pit after removal of the steel was monitored,the ground settlement and deep horizontal displacement monitoring data from steel sheet pile extraction of cable tunnel in Nanjing were compared with the simulation results,the rationality of the numerical simulation was verified,by the different elastic modulus and the law of ground settlement around the pile was analyzed. The results show that when the elastic modulus of cement soil does not exceed 600 MPa,the elastic modulus of cement will increase by 100 MPa,and the average cumulative settlement will decrease,the extent of which is between 16. 2% and 19. 5%,the change of elastic modulus effectively reducing the ground settlement within 6 m of the steel sheet pile; The difference in the ground settlement formed by the different pile excavation sequences is not more than 0. 65 mm.