无隔水层越江隧道土压平衡盾构渣土改良试验研究

Experimental Study on Soil Improvement of Earth Pressure Balance Shield for Cross-River Tunnel

对于全断面砂层的盾构掘进隧道,当盾构所穿越的高透水性中砂地层渗透系数达1.10×10^(-2) cm/s,且其上部水头较高时,发生喷涌的风险极大,一旦发生喷涌严重时可导致盾构隧道整体失稳,因此,必须对渣土改良进行深入研究。文章就福州市轨道交通1号线越江隧道土压平衡盾构渣土改良技术要求、渣土改良试验添加材料、试验内容和试验结果进行分析、阐述。

For the whole profile section of sand layer of shield tunneling, when the shield is boring through high permeable formation sand with permeability coefficient up to 1.10 × 10^-2 cm/s, and the water level at the upper part of the section is high, water gushing and inflow risk increases greatly. In the event of a serious gushing, it can lead to instability of the shield tunnel. Therefore, it is necessary to carry out in-depth study on muck improvement. The paper analyzes and discusses the technical requirements on the improved muck of tunnel earth pressure balance（EPB） shield for the under crossing river Fuzhou transit line 1, ingredient materials for muck improvement conditioning test, content in the test and the test results.