Laslett算法和广义H-H算法在不同迹长层次下的适用性讨论

DISCUSSION ON APPLICABILITY OF LASLETT ALGORITHM AND GENERALIZED H-H ALGORITHM UNDER DIFFERENT LEVELS OF TRACE LENGTHS

结构面平均迹长估算的Laslett算法和广义H-H算法虽然在理论上具有严密的推导过程,但实际应用时,由于迹长层次不同,两种算法估值精度不同。在利用开挖边坡所揭露的全迹长资料对不同迹长层次下两种算法的估值精度进行检验的基础上,讨论了两种算法的适用性,并针对工程中所采用的测量窗口高度通常较小这一实际情况,对广义H-H算法在小窗口长迹长层次下的迹长估计值进行适当修正。综合研究结果,建议:(1)小窗口短小迹长层次情况下采用Laslett算法进行迹长估计;(2)小窗口长大迹长层次情况下采用乘以修正系数x=2的广义H-H算法。

In theory,there is a rigorous deducing process for the Laslett algorithm and the generalized H-H algorithm under the mean trace length estimation of discontinuities.However,they have different accuracies of estimated values on different trace length levels.This study carries out tests on the accuracy of estimated values from both algorithms and evaluates their applicability,based on the full-trace length data of excavated slopes.Because the height of test windows in engineering are small,this paper has amended the estimated values of the generalized H-H algorithm.The values are calculated under the conditions of small test window and long trace length level.The research results indicate that（1）under the conditions of small test window and short trace length level,the Laslett algorithm is adopted;（2）under the conditions of small test window and long trace length level,the generalized H-H algorithm is adopted.A modified coefficient 2 is suggested.