基于弹性波速比的岩体强度参数估算方法

Estimation method of rockmass strength parameters based on elastic wave velocity ratio

针对传统的岩体强度参数估算方法考虑风化程度的研究成果较少的不足,引入弹性波速比λ,提出了岩体强度参数的估算方法。以贵州省二叠系两种典型岩体(灰岩和泥岩)为例,讨论了参数λ和正应力σn对岩体强度参数的影响。主要研究成果为:基于弹性波速比与Hoek-Brown强度准则,探讨了不同风化程度岩体抗剪强度参数折减系数的确定方法;研究了正应力与弹性波速比对不同风化程度灰岩与泥岩岩体瞬时抗剪强度参数的影响,结果表明,岩体所处的环境与风化程度是影响岩体剪切强度参数的主要因素;通过多项式拟合,建立了灰岩与泥岩扰动与未扰动情况下不同风化程度强度折减系数的计算公式,从理论上探讨了两种主要岩体不同风化程度对强度参数的影响。

Traditional estimation method for strength parameters of rock mass does not consider much weather de-gree.The estimation method of strength parameters of rock mass is put forward by introducing elastic wave veloc-ity ratioλ.Taking hard rock（limestone）and soft rock（mudstone）as examples,the influence of parameter（λ）and normal stress（σn）on strength parameters of rock mass is discussed.The results show clearly that elastic wave ve-locity ratio is an index of weathering zone,based on it and Hoek-Brown strength criteria in this paper,different weathering degree reductive coefficient of shear strength is discussed.The influence of normal stress and elastic wave velocity ratio on shear strength parameters of different weathering degree of rockmass is investigated.The study shows that normal stress and weathering degree of rock mass are main factors influencing strength parame-ters.The estimation formulas of weathering degree reductive coefficient on limestone and mudstone are suggested by using polynomial fitting method.The study presented in this paper can provide a scientific basis for the stability evaluation of rock mass slope,foundation evaluation and engineering optimization design.