苏州地区小净距盾构下穿既有线掘进参数分析

Analysis of tunneling parameters of small clear distance shield under existing line in Suzhou area

苏州地区小净距盾构下穿既有线工程较少,依托苏州市轨道交通6号线工程金尚路站—桑田岛站区间盾构下穿既有2号线工程,对盾构掘进参数进行分析。研究结果表明:结合自动化监测,提高土仓压力,进行渣土改良,进行二次注浆等,这些措施可确保既有线最大变形量在5 mm左右;建议在掘进过程中,盾构推力为14000~29000 kN、盾构刀盘扭矩为800~2300 kN·m、土仓上部前压力为1.62~2.75 bar、同步注浆量为5.0~7.2 m^(3)、注浆压力为2.5~3.0 bar,根据自动化监测实时调整,可以很好地控制结构变形,可供类似下穿工程参考。

There are few shield tunneling projects under existing lines in Suzhou.Based on the shield tunneling project between Jinshang Road station and Sangtiandao station of Suzhou rail transit line 6,the shield tunneling parameters are analyzed.The results show that the maximum deformation of the existing line can be ensured to be about 5 mm by combining automatic monitoring,increasing the soil bin pressure,improving the muck and secondary grouting.During tunneling,the recommended thrust of shield is 14000~29000 kN,the torque of shield cutterhead is 800~2300 kN·m,the front pressure at the upper part of soil bin is 1.62~2.75 bar,and the synchronous grouting amount is 5.0~7.2 m^(3),grouting pressure is 2.5~3.0 bar.It can be adjusted in real time according to automatic monitoring,which can well control the structural deformation,and can be used as a reference for similar undercrossing projects.