摘要
Hoek-Brown经验准则(2002版)考虑施工扰动对岩体参数劣化效应,并提出扰动系数D,但仅为粗略定性化描述。现应用声波测试法获得的岩体波速降λ对扰动系数D进行优化处理,并将优化后的Hoek-Brown经验准则运用于开挖扰动引起岩体弹塑性变形特征方程的求解研究,进而可实现较精确表示围岩塑性圈半径。为验证该理论的合理性,综合运用声波测试法、位移监测法等监测手段及有限元数值模拟法予以对比分析。此外,考虑开挖扰动变形特征场地效应,提出可拟合不同岩性、不同开挖方式的变形与开挖扰动经验公式。工程实例计算结果表明:对Hoek-Brown经验准则(2002版)扰动系数D的优化合理,用其可计算开挖扰动引起的围岩弹塑性变形特征值。并可准确求得塑性圈半径值,同时,拟合得到变形与开挖扰动经验公式可满足不同工程需要,具有一定合理性。所获结果可为Hoek-Brown经验准则(2002版)及地下洞室开挖扰动引起岩体变形特性研究提供一定方法参考。
Considering the deterioration effect on rock mass parameters caused by construction disturbance,the disturbance factor D is proposed in the Hoek-Brown empirical criterion（2002 edition）,but it is only a rough qualitative description.The wave velocity drop λ obtained from sonic wave testing is employed to optimize the disturbance factor D;and the optimized Hoek-Brown empirical criterion can be used to get the solution to the characteristic formula of rock mass elastoplastic deformation caused by excavation disturbance.Thus,the radius of plastic ring can be represented more accurately.In order to verify the rationality of that theory,various monitoring methods,such as sonic wave testing and displacement monitoring methods,etc.,have been applied and the finite element numerical simulation method is used to compare with the monitoring methods as well.In addition,taking into account the site effect of deformation characteristics induced by excavation disturbance,an empirical formula of deformation and excavation disturbance fitted with different lithologies and excavation methods is put forward.The calculation results of an engineering example indicate that the optimization of disturbance factor D from the Hoek-Brown empirical criterion（2002 edition） is reasonable;and it can calculate the eigenvalue of rock mass elastoplastic deformation caused by excavation disturbance and accurately obtain the radius of plastic ring.Furthermore,the empirical formula of deformation and excavation disturbance obtained by fitting can satisfy different engineering demands with certain rationality.This study can provide a methodological reference for researching the Hoek-Brown empirical criterion and the characteristics of rock mass elastoplastic deformation caused by excavation disturbance in underground caverns.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2010年第7期1355-1362,共8页
Chinese Journal of Rock Mechanics and Engineering
