土压平衡盾构喷涌发生机理研究

Research on the mechanism of the spewing in the EPB shield tunnelling

摘要: 土压平衡式盾构施工中 ,进入压力舱的土体如果难以形成“塑性流动状态” ,诸多的施工难题会随之产生 ,喷涌就是非常值得关注的一种。本文建立了盾构机内水压力递减模型 ,基于模型推导了水压力和流量的变化关系来用于解释喷涌发生的机理。在此基础上 ,喷涌的发生条件得以明确。对于影响喷涌的参数 ,文中进行了敏感性分析。最后 ,国内四大城市盾构隧道施工的土层参数被用于分析其发生喷涌的可能性 ,得出了比较符合工程实际的一些结论

Abstract: The key to success in Earth-Pressure-Balanced(EPB) shield is converting the muck excavated from the cutter face to the plastic soil,or the spewing occurs usually and harmfully.In this paper,the relation model of water pressure and flow is built to explain the spewing mechanism.And consequently,the critical conditions of the spewing are put forward.The sensitivity of the parameter influencing the spewing is analyzed.At last,the possibility of spewing was analyzed for the engineering projects of four cities.