基于WLSM的多参数裂隙岩体统计均质区划分

Evaluation of statistical homogeneity of jointed rock masses based on weighted least-square method

岩体统计均质区的划分一直是岩土工程领域研究的重要课题。大多学者采用产状或者其它单一参数划分岩体统计均质区,却很少有人考虑多参数进行划分研究。考虑了产状、间距、张开、迹长和粗糙度共5个参数,提出了一种划分裂隙岩体统计均质区的新方法,即采用权的最小平方法确定参数的权重并用相关系数法计算研究区裂隙各个参数之间的相关性,从而确定均质系数以此实现对裂隙岩体统计均质区的划分。通过工程实例即云南省马吉水电站左岸坝肩某一高程相邻4个平硐的岩体结构统计均质区划分,分析了多参数对裂隙岩体统计均质区划分的影响。研究结果表明:裂隙岩体统计均质区划分与裂隙产状、间距、张开、迹长和粗糙度等因素有关并成功划分了研究区的统计均质区,证明了该方法的可行性。

Theidentification of structural homogeneity has been an important topic in the fieldof geotechnical engineering. Most of scholars use joint orientations or the other joint parameters to identify statistically homogeneous regions or structural domains in a jointed rock mass. However,few studies have been conducted by integrating both of them.Five parameters are considered for this identification,namely： joint orientation,spacing,aperture,trace lengthand roughness. Based on the weighted least-square method,the weights of the parameters are obtained. A statistical parameter,known asthe correlation coefficient,is used to quantify the degree of the similarity between the joint parameters collected from the studied regions. The overall homogeneity of the rock mass is determined based on the homogeneity index. A practical engineering case is analyzed, illustrating the effect of the multiple parameters collected from four adjacent adits at Maji dam site on the left bank of the Nujiang River in YunnanProvince onidentification ofstatistical homogeneity in fractured rock mass. The results indicate that the identification ofstatistical homogeneity is influenced by many factors such as the joint orientations,spacing,aperture,trace lengthand roughness.The statistical homogeneousdomains in thestudied regions are successfully divided, indicatingthe feasibility ofthe proposed method.