千枚岩滑坡体段明洞开挖复合支挡结构处理技术

The Processing Technology of Composite Support Structure Applied for Excavating Open-cut Tunnel Located in the Phyllite Landslide

某隧道明洞浅埋偏压,位于全风化千枚岩地层,地下水位出露浅,现场施工诱发坡体溜坍,通过滑坡体形态勘查,地质钻孔核查确定了滑动面。为解决滑坡体前缘明洞开挖卸载土体诱发坍体继续滑移,研究了滑坡体Π型抗滑桩、明洞开挖桩-锚-梁复合支挡结构处理技术,简述了施工注意事项。施工监测表明,滑坡体Π型抗滑桩、桩-锚-梁复合支挡结构加固处理技术效果明显,安全可靠。

A shallow buried open-cut tunnel with bias pressure is located in the fully weathered phyllite stratum, where the groundwater level is shallow, and the slope collapse is caused by field construction. Through the geological exploration of the landslide body, the geological drilling verification determines the sliding surface. In order to address the continuous slipping of the collapse body caused by the excavation at the front edge of the landslide body, the paper studied the treatment technologies of the landslide body gantry type anti-slide piles, the excavation pile of an open-cut tunnel and the composite retaining structure of pile-anchor-beam. Besides, it briefly introduced the the matters needing attention in the construction. The construction monitoring shows that the reinforcement technologies of gantry type anti-slide piles and pile-anchor-beam composite retaining structures are effective and safe.