云南省祥(云)-临(沧)公路红土坡隧道变形原因及加固方案

云南省祥(云)-临(沧)公路红土坡隧道，在施工过程中变形严重，洞内数次冒顶、产生地面陷落，并诱发滑坡，严重影响了施工进度并造成较大经济损失。文章根据现场勘查及变形监控量测资料，详细论述了隧道变形特点，从地层岩性、构造、地应力条件、地下水作用、施工工艺、滑坡影响等方面综合分析了隧道变形原因。红土坡隧道变形是软弱的地层岩性、地应力条件改变、地下水作用、施工工艺以及滑坡偏压等各种因素共同作用的结果。且隧道变形诱发滑坡，滑坡又促使隧道进一步变形。基于此，文章提出了首先对滑坡进行支挡，再对隧道围岩进行加固的整治思路，并提出具体工程方案。整治工程实施后，红土坡隧道变形已得到完全控制，取得良好的治理效果。

Cause of deformation and reinforced methods of Hongtupo tunnel on Xiang-lin(Xianyun-Lincang) Highway in Yunnan Province

Hongtupo tunnel of Xiangyun-Lincang Highway deformed seriously. Tunnel caving, surface collapse and landslide occurred many times during the construction. The happening of several severe hazards affected the project on schedule and brought on a great economic loss. Base on the data of the survey, this paper discusses the characteristics of the tunnel deformation in detail, and analyzes the reasons from the points of the geological condition, structure, the geologic stress field, the groundwater function, the construction technics, the landslide influence, etc. It is considered that Hongtupo tunnel deformation is the corporate result of the weak strata rock, the geologic stress changing, the groundwater function, the construction technics, the landslide deviating pressures, etc. The tunnel deformation causes the landslide, in reverse the landslide leads to the tunnel deforming further. So the paper puts forward an idea that the landslide is retained first and then the surrounding rocks of the tunnel are reinforced. After the constructing, the Hongtupo tunnel deformation has been controlled completely.