越江地铁隧道土压平衡盾构施工土压力分区研究

On Earth Pressure Balance Shield Construction of Cross-River Tunnel

在江底进行地铁盾构施工,若土仓压力控制不当,会使江水涌入掘进面,带来很大危险。为降低盾构越江施工的风险,以杭州地铁1号线盾构隧道越江工程为背景,根据该区间工程的线形、地质水文特点及周边环境的情况,将盾构越江段分为6个区段,并分析了各区段的特点。在试验段施工参数实测数据分析的基础上,根据越江段的分区情况和施工环境等条件,提出了越江段的土仓压力合理设定值为0.15～0.38 MPa。越江段土仓压力实测结果为0.21～0.52 MPa,土仓压力实测值与理论值的比值为1.08～2.17。通过对土仓压力进行分区研究,为土压平衡盾构顺利穿越钱塘江提供了一定的技术参考,也可为其他越江盾构工程提供借鉴。

There are many cross-river shield tunnel projects in metro construction in China. If the soil chamber pressure is not controlled during the shield tunnel construction beneath the riverbext, tremendous hazard will happen once the water gushes into the heading face. Hangzhou metro Line 1 is taken as an example to explain how to reduce the risks for cross-river shield tunnel construction. Where the shield-cross-river section is divided into 6 areas （A, B, C, D, E, F） and the characteristics of each section are studied according to the linear of the section engineering, the geological and hydrological characteristics, as well as the surrounding environment. Considering the condition of partition section and the construction environment and so on, the setting values of earth pressure in cross-river section are proposed from 0.15 to 0.38 MPa based on an analysis of the construction parameters in test sections. The measured data of earth pressure in cross-river section is about 0.21 -0.52 MPa, while the earth pressure ratio of measured values and theoreti- cal values is about 1.08-2.17. Technical means are taken to guarantee the earth pressure balanced shield construction under Qiantang River by means of the partition research of earth pressure, and this experience could be used as a reference for future construction of shield tunnels.