岩溶强发育区盾构隧道施工技术研究

Research on Shield Tunnel Construction Technology in Karst Development Area

为了研究强发育溶洞区溶(土)洞处理和盾构机适应性问题,依托广州地铁12号线棠溪站—南航新村站区间工程,总结了强发育岩溶的探边、包络图绘制、工程量计算、处理范围和注浆措施及注浆配合比。现场注浆取芯完整、实测标贯击数为15~20击,固结状态和强度满足要求。总结了溶(土)洞注浆量的计算方法,明确了见洞面积、平均洞高、浆液扩散系数、注浆填充系数的计算和取值方法。区间工程采用了泥水/土压平衡盾构双模设计,并将螺旋输送机串联到泥水环流系统中,解决了因强风化带和粉质黏土引起的渣土滞排问题,保证了土仓压力波动在0.015MPa以内。

In order to study the treatment of karst cave in strongly developed karst cave area and the adaptability of shield machine,based on the interval project of Tangxi Station to Nanhang New Village Station of Guangzhou Metro Line 12,the boundary detection,envelope diagram drawing,engineering quantity calculation,treatment range,grouting measures and grouting mix ratio of strongly developed karst are summarized.The on-site grouting core-taking is complete,the measured standard penetration number is 15~20,and the consolidation state and strength meet the requirements.The calculation method of grouting amount of karst cave is summarized,and the calculation and value method of cave area,average cave height,slurry diffusion coefficient and grouting filling coefficient are clarified.The double-mode design of slurry/earth pressure balance shield is adopted in the interval project,and the screw conveyor is connected in series to the slurry circulation system,which solves the problem of delayed mucking caused by strong weathering zone and silty clay,and ensures that the fluctuation of chamber earth pressure is within 0.015 MPa.