盾构切桩穿越建筑群时房屋倾斜影响分析

House tilting impact analysis of metro shield tunnel crossing building group with cutting stakes

地铁盾构切桩穿越建筑群会导致房屋发生不均匀沉降,借助TS30测量机器人对深圳地铁9号线某小区的9号楼~13号楼群进行实时动态监测。监测结果表明:左、右线先后穿越9号楼的过程,叠加应力可减小房屋长边的倾斜值,最大斜率仅-0.24×10^(-3)mm/m,但未改变短边的倾斜方向;房屋长边“V”型构造产生的附加拉力会引起外墙竖向裂缝;左线穿越10号、11号楼和右线穿越13号、12号楼的过程,房屋长边的倾斜值大于对边和临边,穿越过程短边的倾斜方向发生逆转;斜率变化集中在刀盘进入房屋至盾尾离开期间,并滞后出现最大斜率,且监测边距离盾构中心越远,滞后现象越明显;盾构快速推进切桩导致长边斜率快速增大,地面同步注浆会减小房屋倾斜,达到房屋纠偏的目的。

It is inevitable for metro shield tunneling to crossing building groups in the city and it will have a large impact on building’s incline distortion while crossing with cutting stakes.In this paper,TS30 Measurement Robot was using to monitor the real-time dynamic deformation of buildings No.9~13 in Shenzhen.The results showed that:While left and right line crossing the house No.9 respectively,it is advantageous of stacked stress for long side to reduce the tilting value,however,the short side was not changed;the additional stress caused by“V”construction of long side had made house vertical cracks.In the process of left line shield tunneling crossing No.10,No.11 and right line crossing No.13,No.12,the tilting value of long side is larger than opposite side and adjacent.However,the inclined direction of short line could be changed while passing through.The change in slope concentrated from cutter in to shield tail out of buildings and the maximum slope delayed occurrence,which was more apparent when monitoring side is far away from shield tunnel.The fast shield tunneling and cutting stakes will make the slope of long side greater,however,synchronizing grounds grouting made the house slope plummeting and achieve rectification.