系列尺度岩体结构面形貌渐进覆盖统计方法

系统合理地统计系列尺度结构面的形貌是不同尺寸结构面代表性取样的前提条件,直接影响到结构面抗剪强度尺寸效应试验结果的有效性。针对传统均匀网格切分法在不同尺寸结构面形貌统计上的不足,提出系列尺度岩体结构面形貌渐进覆盖方法,该方法以不同尺寸试样为单位样本,以不同推进间距沿正交方向分别逐步推进,获得覆盖整个结构面的若干不同尺寸统计样本。通过对渐进覆盖方法的基本特征分析,提出样本量、样本覆盖区域和样本覆盖重叠度分别与推进间距的关系式,进一步的实例分析表明,单位样本的逐步推进使样本交叉错位,可获取更丰富的单位样本,并覆盖部分缺失区域形貌,增加了各尺寸的样本量,提高了整体样本的精度。通过该方法,将全面获取系列尺度结构面的渐进起伏形貌特征,为不同尺寸试样的样本统计提供代表性取样依据。

A progressive coverage statistical method for series scale surface morphology of rock joints

Systematic and reasonable statistics of the morphology of rock joints are the precondition for representative sampling of different size discontinuities,which directly impacts the validity of the scale effect test on joint shear strength. To overcome the shortcoming of the traditional uniform mesh statistics segmentation method in terms of different scales of rock joints,a progressive coverage statistical method,taking different size sample as unit sample and extracting the statistical samples of the entire rock joint in orthogonal directions with different step distances was proposed for representing the morphology of various sizes of rock joints. Based on the analysis of the basic characteristics of the proposed method,formulas between the sample capacity,coverage and coverage overlap with the advance distance were proposed. Case study shows that,with the propulsion of the unit sample,the sample overlap and a more complete unit sample can be obtained,which covers partial missing area morphology,increases the sample size and improves the accuracy of the whole sample. The progressive undulating morphology of series scale rock joints can be entirely derived by this method,which provides the sampling basis for various size samples.