地铁区间隧道下穿人防空洞袖阀管注浆工程措施应用

Grouting engineering measures for sleeve valve pipe of subway tunnel passing through air-raid shelter

合理的加固措施对复杂地层环境下地铁隧道下穿人防空洞施工的安全性及稳定性具有重要影响。西安地铁十四号线港务大道站-贺韶村站的区间隧道为典型人防空洞穿越区,工程采用环状台阶法开挖,通过袖阀管注浆+超前小导管支护+棚管支护等多种支护手段相结合的方法维持围岩稳定,结合现场地表沉降、围岩压力及衬砌结构内力监测结果以及5种工况(无加固措施、超前小导管支护、超前小导管+棚管支护、袖阀管注浆支护及全注浆支护)下的数值仿真结果,表明袖阀管注浆支护手段在减小地表沉降及控制隧道围岩收敛方面效果尤为显著,是处理城市地铁区间隧道下穿人防空洞的最优加固措施。

Reasonable reinforcement measures have an important impact on the safety and stability of the construction of subway tunnels under man-made air-raid shelters in complex strata environments.The tunnel between Gangwu Avenue Station and Heshaocun Station of Xi′an Metro Line 14 is a typical air-raid shelter crossing area.The project is excavated by annular bench method.The stability of surrounding rock is maintained by combining sleeve valve pipe grouting+advanced small pipe support+shed pipe support.Combined with the monitoring results of surface settlement,surrounding rock pressure and internal force of lining structure,and the numerical simulation results under five working conditions(no reinforcement measures,advanced small duct support,advanced small duct+shed pipe support,sleeve valve pipe grouting support and full grouting support).It shows that the sleeve valve pipe grouting support method is particularly effective in reducing ground settlement and controlling tunnel surrounding rock convergence,and it is the best reinforcement measure for dealing with urban subway tunnel passing through air-raid shelter.