对块体理论的探讨与失稳块体的三维定位

Block theory locating unstable rock blocks in three-dimensional space

对于由地质构造面纵横切割的多裂隙岩石块体的稳定分析,块体理论不失为一种有效的分析手段。但是,它在分析过程中仅考虑结构面和开挖面的产状,所以必须根据开挖面的地质素描图才能确定失稳块体的具体位置。因此,在事实上它无法在开挖施工之前就准确预测失稳块体的位置。本文根据地质结构面的空间特性,利用现代科学中的CAD技术,在开挖工程施工之前,我们就设法在计算机上真实地模拟地下工程建筑物及其周围地质环境以及施工演进过程。从而随着开挖施工的演进,逐个寻找出失稳块体的形状、特征和空间位置,进而为工程设计处理提供有效的依据。

Block theory is an effective method to analyse stability of rock mass crisscrossed by geologic structure planes. However this method needs the data of occurrences of stucture planes and excavating faces collected during excavation. It may datermine the exact location of unstable rock blocks only if the geologic field sketch is completed. Therefore, it is unable-to forecast exactly the space location of unstable rock blocks before excavating.According to the space characteristics of geologic structure planes and using CAD technology the authors of this paper try to simulate realistically the geologic environment near the underground excavation as well as the construction evolution process before excavation by computer. With the gradual progress of excavation we can find one by one the shape, feature and space location of unstable rock blocks.The results would be useful for the disign of underground excavation and preventive measuves.