适用于半迹长测线法的岩体结构面迹长与直径关系新模型及新算法

NEW MODEL OF RELATION BETWEEN ROCK DISCONTINUITIES TRACE LENGTH AND DIAMETER FOR SEMI-TRACE SCANLINE SAMPLING AND NEW ALGORITHM

适用于半迹长测线法的岩体结构面迹长与直径概率关系需要研究,基于弦端点在圆周上随机分布、弦中点在圆某一直径上随机分布、弦中点在扇形内随机分布、弦中点在扇形圆弧且直径上同时随机分布、弦中点在扇形直径上随机分布(广义模型)这5种不同等可能假设,得到未删截半迹长与直径的5种概率关系模型,理论与实例证明前4种模型在半迹长测线法中不适用或适用性不强、广义模型适用性强,5种模型填补未删截半迹长与直径概率关系方面的空白。当直径服从均匀分布形式时,提出广义模型直径新算法,在汶川地震中得到成功应用,值得推广。

Probability relation between trace length and diameter of rock discontinuities applicable for semi-trace scanline sampling needs to be studied.And five kinds of possibilities are assumed as follows：endpoints of chords are distributed randomly on circumference;midpoints of chords are distributed randomly on a circular diameter;midpoints of chords are distributed randomly in sector;midpoints of chords are distributed randomly both on sectorial arc and diameter;midpoints of chords are distributed randomly on sectorial diameter（generalized model）,five models of probability relations between untruncated-uncensored semi-trace length and diameter are acquired.Theory and practice demonstrate that the former four models are not applicable or not quite applicable for semi-trace scanline sampling;while generalized model is quite applicable.The five models supply a gap in previous knowledge of relation between the probability densities of untruncated-uncensored semi-trace length and diameter.When diameters follow uniform distribution pattern,a new diameter algorithm of generalized model is proposed.The new algorithm is applied to Wenchuan earthquake successfully and worth popularizing.