软岩隧道围岩变形季节性特征与防控措施研究

Seasonal Characteristics of Surrounding Rock Deformation in Soft Rock Tunnel and Prevention Measures

以香丽高速洼里别隧道为依托,通过隧道围岩变形监测结果,分析了炭质板岩隧道围岩变形与季节性降雨之间的关系,研究了围岩旱季和雨季隧道施工围岩变形差异的原因,提出隧道围岩大变形防控措施。结果表明,受季节性降雨的影响,洼里别隧道围岩变形呈现出一定的季节性特征,较于旱季时期,雨季施工时围岩变形呈现出变形量大且变形速率快的特点;围岩大变形因围岩条件、地下水及施工原因共同影响产生,而炭质板岩的软化性、崩解性及其岩层倾角是引发围岩大变形的内因,地下水则是造成围岩变形呈现出季节性特征的主要原因。最后,基于三个主要影响因素,提出适用于洼里别隧道的围岩变形防控措施,采用控制措施后,现场施工效果良好。

This paper analyzed the relationship between the surrounding rock deformation of a carbonaceous slate tunnel and the seasonal rainfall,based on the field monitoring results. To propose the prevention and control measures for large deformation in the surrounding rock,the difference of surrounding rock deformation during tunnel construction between the dry season and the rainy season was studied. The results show that the surrounding rock deformation has certain seasonal characteristics. Compared with the dry season,the deformation in the rainy season is larger and the deformation rate is faster. Besides,surrounding rock conditions,groundwater and excavation are the main factors that contribute to large seasonal deformation of surrounding rock. Finally,based on the above three main influencing factors,measures for deformation prevention and control of surrounding rock in Walibie tunnel are proposed. The research can provide guides for subsequent construction of the tunnel.