岩体不连续面迹长与直径间的概率关系模型分析

由于“随机”概念的模糊性，在假定不连续面为薄圆盘及弦长作为迹长的前提下，基于迹线端点在圆周上均匀分布、迹线中点在直径上均匀分布、迹线中点在圆面域内均匀分布这3种明确而又不同的“随机”含义，可以得到3种合理的迹长 与直径 间的概率关系模型。通过对这3种模型进行分析认为：其在各自的“随机”含义下都是正确的，只是适用条件各异；野外实际可行的条件是介于模型2 和模型3之间的，合理地分析应该同时考虑这两种模型。在实际应用中，应该首先对所有取样面产状之间的关系进行分析，根据其结果来分配给模型2和模型3以某种权重，这样得到的迹长与不连续面直径之间概率关系更具合理性，其结果弥补了目前国内外进行的相关研究仅仅考虑到第2类模型的不足。

Analysis of three probability models between trace length and diameter of rock discontinuities

The conception of "randomness" is so fuzzy that there are three reasonable probability models between the trace length l and the diameter d of discontinuities under the presupposition that the discontinuities is thin disc and the chord is the trace.The three probability models are based on the three specific but different definitions of "randomicity": the end points of trace lines distribute evenly on the cycle;the midpoints of trace lines distribute evenly on the diameter;and the midpoints of trace lines distribute evenly within the disc.The following analysis is performed and found that the three models are all correct exactly under their corresponding presuppositions and they fit different conditions.The field condition is between the model 2 and model 3,and so a reasonable study should give consideration to these two models at the same time.A good research should firstly study the distribution of the occurrences of those outcrops,and then give the model 2 and model 3 certain weights according to the relationship of the outcrops in order to get a more reliable probability model between the trace length l and the diameter d of discontinuities.The results make up the defect of present theories in which only the model 2 is considered.