摘要
节理大小主要指节理空间延伸范围,对于节理泊松圆盘模型,节理大小可以用圆盘直径表示。Warburton的方法需要先假设直径的分布形式,理论上正确,但并不实用。不假定节理直径的可能分布,提出一种新的方法估算节理直径分布,该方法在已知节理迹长分布基础上,通过设定不同节理直径平均值初值,计算相应节理直径分布,得到不同节理直径平均值初值和数值计算节理直径平均值之间的相对误差。分析相对误差与节理直径平均值初值之间的相互关系,当误差为0时,得到数值计算最佳节理直径平均值,从而获得相应节理直径分布。采用节理直径负指数和对数正态分布2种理想分布来验证数值方法的有效性,结果理论节理直径平均值和数值计算节理直径平均值之间的相对误差很小,且节理直径分布和理论节理直径分布一致。通过理论节理直径平均值和标准差变化对数值方法进行参数分析,研究数值方法计算节理直径分布的适用性。在节理直径平均值较大而标准差较小条件下,利用数值方法,所得节理直径分布更加准确。利用该数值方法研究节理直径分布简便实用。将该方法应用于我国高放废物处置库预选区甘肃北山芨芨采石场结构均质Ⅱ区,获得该区岩体节理直径分布。
The joint size is the extension of the joint plane in space. For the joint Poisson disc model, the joint size can be represented by the disc diameter. Warburton＇s method is right theoretically, but not practical in determining the joint probabilistic distribution. A new method for estimating the joint diameter distribution is proposed without using the joint probabilistic distribution. With the variation of the initial mean values of the joint diameter, the relative errors between the initial mean values and the calculated values by the numerical method can be acquired. The relationship between the relative errors and the initial mean values is analyzed. When the error is zero, the optimal joint diameter is obtained by numerical method, and so is the joint diameter distribution. To verify the numerical method, two kinds of theoretical joint diameter distributions are adopted： negative exponential and lognormal distributions. The errors between the theoretical joint diameter and the calculated joint diameter by the numerical method are very small. The theoretical joint diameter distribution and the joint diameter distribution by the numerical method are uniform. The parameter analysis is implemented to determinate the available condition of the numerical method. Especially, the accuracy by the numerical method is better when the mean value of the joint diameter is relatively large and standard deviation is small. From the results above, it is concluded that the numerical method for calculating the joint diameter distribution is simple, valid and accurate. The numerical method is used to analyze the joint data of the statistical homogeneous domain II of the Jiji quarry-the preselected area in Beishan area, Gansu Province for Chinese high-level radioactive waste repository. The diameter distribution is acquired by using trace distribution from the multi-circular window sampling method.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2008年第A02期3503-3508,共6页
Chinese Journal of Rock Mechanics and Engineering
基金
国家重点基础研究发展规划(973)项目(2002CB412704)
国家自然科学基金资助项目(50374064
50334060)
关键词
岩石力学
节理迹长
数值方法
节理直径
高放废物处置库
rock mechanics
joint trace length
numerical method
joint diameter
high-level radioactive waste repository
