福州地铁强承压裂隙水碎裂岩层盾构防喷涌技术

Anti-spewing Techniques for Shield Tunneling through Surrounding Fragmentation Rock with Pressure-bearing Crevice Water in Fuzhou Subway

针对福州地铁强承压性裂隙水碎裂状岩层,研究有效的盾构防喷涌技术,提高掘进效率,保证施工安全。首先,通过涌水量预测计算,找到了渗透系数过大、水量充足、极易发生喷涌的区段;然后,通过实践探索提出了采取地面降水井工程措施降低水压、对盾构螺旋输送机进行改造控制出渣和排水的防喷涌技术。通过该项技术的应用,盾构在通过易发生喷涌地段时,减少了喷涌的发生次数和喷涌量,保证了工期,降低了施工成本,地表沉降也满足了沉降控制标准的要求。

Aimed at the fragmentation rock with pressure - bearing crevice water in Fuzhou Subway, anti - spewing techniques for shield tunneling are researched and developed so as to improve the efficiency of shield tunneling and ensure the construction safety. First, the tun- neling sections, which are extremely easy to spew because of large coefficient of permeability and abundant underground water, were found. Then,through researching and practicing, anti - spewing techniques, including reducing the pressure of underground water with ground dewatering wells and controlling the sediment discharge and the water drainage by reforming the screw conveyors, were devel- oped. Through the application of these techniques, when the shield tunneling pass through the easy - spewing sections, the frequency and quantity of spewing will decrease, the construction period will be shorten, the construction cost will be saved, and the ground settlements will meet the requirements of control standards.