岩溶坝区溶蚀岩体的渗透性变异研究

STUDY ON VARIABILITY OF PERMEABILITY OF CORRODED ROCK MASS IN KARST DAM REGION

通过对溶蚀岩体渗透变异特性的研究,提出了一种确定渗透性变异的方法,即基于“3σ法则”的误差传播函数法。先根据“3σ法则”求得溶蚀岩体统计变量的端点,再利用误差传播函数法基于立方定律求得溶蚀岩体的渗透性变异。将裂隙岩体与孔隙溶洞区别考虑,补充和完善了克立格随机场理论和Vanmarcke 相关性理论对岩土参数变异的研究。基于现场灌浆平硐揭露的工程地质统计资料,对清江水布垭工程左岸帷幕线上部分段进行了渗透性变异的量化研究。研究结果表明,该方法简单适用,且在确定岩溶坝区渗透参数的统计量基础上,可进行随机渗流计算。

Based on the uncertainty risk analysis theory, the depositional environment of the karst dam region is investigated. The method to describe the infiltration characteristics is systematically studied. The variability of permeability and the describing method of the corrosion rock mass are investigated. A new method measuring the variance of permeability is proposed, namely the error spreading function approach based on 3σ principle. The extreme values of the statistics parameters such as the width, spacing of the crack, and radius of the karst pipe can be calculated according to 3σ principle. And then the variance of permeability is obtained by using the cube law. By discriminating the jointed rock mass and pore karst cave, Kriging's random field theory and Vanmarcke's relativity theory on the study of geotechnical parameter variance are renewed and improved. Based on the geology statistical data in the field, the variance of permeability of the corroded rock mass in the grouting adit of Qingjiang Shuibuya project in a typical karst region in south China is computed. The proposed method is proved practical and simple. With variance of permeability provided, the random waterpower model can be constituted and then random permeability calculation can also be carried out.