定量化GSI在估计岩体力学参数中的应用研究

摘要

Hoek-Brown strength criteria is widely applied in fissure rock-mass,although the qualitative relation-ship among rock structure characteristics,rock surface condition and Geological Strength Index (GSI)has been offered by E.Hoek,surrounding rock index cannot be provided according to survey report in highway tunnel engi-neering along with failure to connect with GSI.Therefore,the quantitative relationship among rock complete coef-ficient (Kv),rock weathering coefficient (Kf)and Geological Strength Index (GSI)was established in order to determine the rock parameters in Hoek-Brown strength criteria.By using this method,the estimates of the sur-rounding rock mechanical parameters were located within standard ranges.When estimates were applied to simu-late the vault settlement of tunnel,the obtained error between simulated and monitored results was within the al-lowable range.Application of this method validated the feasibility of determining the rock parameters of Hoek-Brown strength criteria,which provides a new practical way to determinate rock mass mechanical parameters of H-B strength criteria for surrounding rock in highway tunnel.%Hoek－Brown强度准则在裂隙化岩体中得到了广泛应用。然而，Hoek给出的岩体结构特征和岩体表面状况与地质强度指标（GS I ）的概化关系，公路隧道工程中无法根据勘察报告给出围岩指标，建立与GS I的对应关系。鉴于此，必须建立岩体完整系数（Kv）和岩体风化程度系数（Kf）与GSI的定量关系，从而确定Hoek－Brown强度准则中所需要的岩体参数值。利用该方法估计公路隧道围岩的力学参数，将该估算值用于模拟隧道拱顶沉降，得到的模拟值与实际监测结果对比，误差在允许范围之内。通过算例验证该方法确定H－B强度准则中岩体参数的可行性，为公路隧道不同围岩的H－B强度准则岩体参数值的确定提供了新的快速、实用的方法。