中文摘要：

半迹长测线法是当前野外结构面数据采集中最为常用的一种采样方法。目前基于半迹长测线法估算结构面平均迹长的研究成果很少。在对基于半迹长测线法估算岩体结构面全迹长概率密度函数及平均迹长的方法进行改进的基础上,通过建立3种新的考虑结构面产状分布特征的迹线与测线的交切概率模型以及新的半迹长累积概率模型,推导得出由半迹长概率密度函数显式表达的全迹长概率密度函数,并据此得到半迹长服从典型概率分布形式时,在结构面产状分布影响下的全迹长概率密度函数及平均迹长。最后应用汶川老虎嘴岩质斜坡单组结构面几何参数对上述成果加以验证,将模拟结果与实测半迹长样本进行对比,结果表明,所提出的方法计算精度明显高于传统方法,证明该算法的优越性。同时对迹长均值与结构面产状关联性进行分析,为测线法野外结构面采样工作提供建议。

英文摘要：

Semi-trace scanline survey is one of the most widely used method to measure discontinuity geometrical parameters in field,while it is hardly to find some correlative researches on discontinuity based on semi-trace scanline method in literature. Technique of determining probabilistic distribution of discontinuity trace length and estimating of mean trace length based on semi-trace scanline surveys was improved. By considering the influence of the discontinuity orientation,three new types of traces and scanline′s intersection probability models and one type of semi-trace length cumulative probability model were built. Hence the probability density functions of trace length and the value of mean trace length with the influence of joints′orientation were obtained. With different types of probability density functions of semi-trace length,the probability density function of trace length expressed with explicit formula by semi-trace length probability density function was determined. Then the geometrical parameters of Laohuzui rock slope discontinuities in Wenchuan area were used to prove the new method. Results of network were compared with the real measured semi-trace length sample. It showed that the average simulative semi-trace lengths from improved model were much closer to the field semi-trace length data than the results obtained by previous method,which indicated the superiority of the proposed method. Finally several suggestions about discontinuities sampling by using scanline surveys were given according to the analysis result of the relationship between the mean trace length and discontinuity orientation.