土压平衡盾构隧道引起的地表沉降规律研究

Study on the Rules of Ground Settlement Caused by Earth Pressure Balancing Shield Tunnel

盾构法作为地铁隧道施工的一种主要施工方法已在我国得到广泛的应用,由施工引起的地层移动和地表沉降是盾构隧道设计和施工中备受关注的问题。以广州地铁3号线某盾构区间隧道为研究对象,运用三维有限差分法对盾构施工过程中影响地面沉降的因素——土舱压力、盾尾注浆压力和地层损失率进行较为系统的研究,可得出结论:影响盾构隧道地表沉降最大的因素为地层损失和注浆压力,增大土舱压力对降低隧道地表沉降的作用非常有限。

The shield driving method, as one of the main construction methods of metro tunneling, has been used widely in China. The stratum movement and ground settlement induced by construction are main issues receiving much concern during shield tunnel design and construction. Taking one certain shield tunneling section in Guangzhou metro line 3 as the object of study and studing the factors influencing ground surface settlement during shield construction by using 3D FDM, including soil pressure in pressure cabin, grouting pressure of shield tail, and strata loss rate. Conclusion is obtained that the most important factors affecting the ground surface settlement of the shield tunnel are strata loss rate and grouting pressure. The effect of increasing soil pressure in pressure cabin is limited to decrease the ground settlement of tunnel.