基于岩体不连续面三维分形维岩体质量评价研究  

Study of rock masses quality evaluation based on 3D fractal dimension of rock discontinuity distribution

作　　者：周福军[1] 陈剑平[1] 徐黎明[1] 谭春[1] 

机构地区：[1]吉林大学建设工程学院,长春130026

出　　处：《岩土力学》2012年第8期2315-2322,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.40872170;No.40472136);高校博士学科点专项科研基金(No.20090061110054)

摘　　要：岩体内部不连续面分布具有随机性、不规则性,但又具有统计自相似性。基于三维随机不连续面网络模拟技术,对岩体结构统计均质区内的不连续面进行计算机模拟,并应用分形理论计算岩体不连续面分布的分形维数。岩体不连续面分布分维数具有尺寸效应,随着岩体尺寸增大分维数减小,到一定程度趋于稳定。这一稳定的分维值称之为表征分维数,用此值描述不连续面分布特征。将岩体不连续面分布的表征分维数与按传统岩体分类标准所得岩体质量等级进行对比,提出以岩体不连续面分布表征分维数为指标的岩体质量分类方法。在岩体分类基础上,提出基于表征分维数的岩体等效抗剪强度指标的折减计算。The distribution of rock masses discontinuities is random and irregular; but in the statistical sense, the property of rock masses discontinuities distribution is self-similar. The three-dimensional network numerical modelling technique is used to establish the model of randomly distributed discontinuities in the statistical homogeneity of structure; the structure of jointed rock masses is regenerated on the screen of computer. Then the fractal dimension of the rock masses discontinuities distribution is computed applying fractals. The distribution of rock masses discontinuities has scale effects; and the fi＇actal dimension of the rock masses structure decreases with the size of the rock masses specimen increasing; but when the specimen dimension increases to a certain value, the fractal dimension varies decreases no more. This certain fractal value is named ＂representative fractal dimension＂, and the value can be used for describing the distribution of discontinuities. By comparing ＂representative fractal dimension＂ calculated above with the rock masses grades classified by the traditional rock masses rating methods, a new method of rock masses quality classification, which takes ＂representative fractal dimension＂ of the discontinuity distribution as the classifying index, is proposed. The equivalent shear strength indexes of rock masses can be calculated, basing on the rock masses quality classification.

关 键 词：分形理论 三维表征分维数 岩体质量 等效抗剪强度指标 

分 类 号：TU451[建筑科学—岩土工程]