某大型地下泵房围岩块体组合模式分析

The Analysis of Block Combination Model of Surrounding Rock of a Large Underground Pump House

大型地下洞室在施工过程中,围岩稳定问题是最主要的工程地质问题之一,以裂隙硬质岩体为主的洞室工程,围岩稳定问题中以块体稳定问题最为典型,块体组合模式更是此类问题分析的关键所在。本文选取滇中引水工程石鼓水源地下泵房为研究题材,主要通过地表测绘及钻孔揭露结构面发育特征等,结合关键块体理论及立体几何学基本理论,从块体空间几何构成结合变形破坏方式,初步归纳出地下泵房部位块体模式主要有:(1)滑塌失稳;(2)坍顶、掉块两种基本破坏模式,以及单滑面型楔体、双滑面型楔体、正锥型楔体、斜锥型楔体及单缓切面薄版型等5种典型的基本单体和组合块体模型。从宏观上对泵房区块体组合进行了初步预判,为围岩稳定综合评价奠定了基础,可为其它工程相类似的裂隙硬质岩体洞室块体组合分析提供参考意义。

In the process of construction of large underground cavern, surrounding rock stability is one of the major engineering geological problem in fissure cavern engineering, hard rock based on block stability problems, the most typical in the stability of surrounding rock, block combination model is the key to this kind of problem analysis. This paper selects the Shigu water diversion project in Yunnan underground pumping station as the research subject, mainly through the surface mapping and drilling structural surface development characteristics, combined with the basic theory of key block theory and solid geometry, from the composition of block space geometry with deformation and failure modes, summarizes parts of underground pumping station block pattern mainly has： the slump the collapse of roof instability; and block out two basic failure modes, and a single slip surface type wedge, wedge type double surface, cone wedge, oblique cone wedge and slow section thin version type 5 kinds of typical basic monomer and combination block model. The preliminary prediction of the block combination in the pump room is made from macroscopic view, which lays the foundation for the comprehensive evaluation of the surrounding rock stability. It can provide a reference for other engineering similar fractured hard rock cavern block combination analysis.