【摘要】 根据围岩中接近屈服面区域的安全程度的差异,对非塑性区的危险程度进行定量研究具有重要的理论意义和工程应用价值。通过分析Mohr-Coulomb准则以及其他屈服准则在主应力空间中非屈服应力点和屈服面的关系,在经典塑性理论框架内定义了屈服接近度指标,并建立了相应于各种不同类型的屈服准则的屈服接近度求解函数。通过对一受单断层影响的城门洞形隧道算例的分析,表明破坏接近度的定义是合理的,这一分析方法可以使得工程师以定量的概念来把握和判断围岩中不同区域的危险性程度,便于相互比较和相似工程间的比较,对于分析隧道及地下工程围岩破坏区的演化及安全度评价具有重要的实用价值。更多还原

【Abstract】 In many cases,it is necessary to realize the importance of the stability discrepancy among the points which are all close to the yield state in the principal stresses space.So the YAI(yield approach index) concept is presented,which denotes the yield approach degree or the difference of the stability of some points in the Haigh-Westergaard space compared with the relative safe point;and the method and rule are provided for the choice of relative safe point.The whole analysis is limited in the frame of plastic theory.This concept allows the possibility of describing the stability state and the progressing transition between stability and instability state of each element or point.So evolution of the stability state of surrounding rock mass in the process of loading can be simulated.The yield approach function is derived out based on the Mohr-Coulomb yield criterion.Finally,a case study is presented to which YAI is applied.更多还原