三峡水库某库段岩体裂隙网络模拟研究

Research on fissures network of jointed rock masses in one section of Three Gorges Reservoir

为合理评价三峡水库某库岸岩体结构特征及工程整治提供依据,对区内岩体进行了裂隙调查及网络模拟研究。研究基于 Monte-Carlo 模拟方法,在技术上进行了探讨和一定改进。如采用了聚类分析法确定裂隙优势产状、用直接法产生随机数、广义RQD 及裂隙线连通率的计算等。根据野外调查及计算机模拟研究,研究区发育有 3 组优势裂隙、平均迹长 1.45 m t左右。间距一般服从对数正态或负指数分布,而走向和迹长基本上不服从常规分布。裂隙线密度在3-6 条/m、t = 0.1 m时RQD 值在 90 %左右、t = 0.7 m 时 RQD 值为 10 %-20 %、RQD 值变化可能影响库岸岩体在不同方向的稳定性。 t t

In order to rationally evaluate engineering properties of rock masses in one section of the Three Gorges Reservoir and provide method for harnessing geological hazards, the probable patterns of discontinuities were calculated and joints network were simulated with the aid of the Monte-Carlo method on the basis of surveying data of discontinuities. Some technical improvements were proposed. There are cluster analysis for classing discontinuity groups, direct method to form joint random numbers, calculation of generalized RQDt and line connection rate. According to surveyed and simulated results, there are 3 sets preponderant discontinuities in researched section, and the average trace length is about 1.45 m, line density of discontinuities is 3 - 6 sets every metre, when t = 0.10 m and 0.70 m, the value of RQDt is 90% and 10% - 20% respectively, and the varying of RQDt along different orientations will affect stability of bank slope.