层间错动带对白鹤滩水电站地下厂房围岩稳定的影响

Influence of Interlayer Staggered Zone on the Stability of Surrounding Rock of Baihetan Hydropower Station Underground Powerhouse

白鹤滩水电站地下厂房洞室群规模巨大,主副厂房洞尺寸达438.0m×34.0m×88.7m(长×宽×高),其间发育的层间错动带C2错动强、性状差,斜切整个左岸地下厂房中、下部边墙,是影响左岸厂房围岩稳定的主要地质构造。为此,建立了左岸厂区地下洞室群整体三维模型,分析了无支护情况下的围岩稳定性,评价层间错动带对地下厂房围岩稳定的影响。在此基础上,建立局部模型模拟层间错动带处理方案,分析地下厂房在支护措施下的围岩稳定性。结果表明,采用纵向混凝土置换洞和横向置换支洞的组合布置形式,层间错动带的剪切错动变形及围岩塑性区深度、局部大变形能得到有效控制,地下厂房围岩整体稳定可得到有效保证。

The scale of underground structure group of Baihetan Hydropower Station is huge.The size of the powerhouse is up to 438.0m×34.0m×88.7m(long×wide×high).Interlayer staggered zone C2 with characteristics of staggered intensely and badness character cutting the lower side wall of underground powerhouse of the left bank,which is the main geological structure affecting the stability of the surrounding rock of underground powerhouse.Three-dimensional model of the underground structure group of the left bank was established to analyze the stability of surrounding rock in the case of without support and evaluate the impact of interlayer staggered zone on the stability of surrounding rock.On this basis,a local model was established to simulate the treatment scheme and analyze the stability of surrounding rock in the case of support.The results show that using the form of combination of longitudinal and transverse concrete replacement tunnels,the shear deformation of interlayer staggered zone,depth of plastic zone and local large deformation of surrounding rock were effectively controlled.Therefore,the whole stability of surrounding rock of underground powerhouse can be guaranteed effectively.