非均质性对岩体应力场反分析结果的影响

从弹性介质的假定出发,利用“等效”节理岩体等效模型和节理岩体统计等效模型,分析了有限单元法位移反分析反算岩体弹性模量和原岩应力场的问题,通过参数研究,讨论了岩体节理和非均质性对位移反分析结果的影响.结果表明,在节理岩体“等效”连续介质力学模型假定下,采用不同力学模型对反算的弹性模量值有较明显影响,而节理岩体力学参数非均质性对反算原岩应力场的影响很小,均质、各向同性假定在原岩应力场实测和位移反分析中是适用的.

Influence of Heterogeneity on Back Analysis Results of Stress Field in Rock Mass

Based on the assumption that the rock mass is of elastic medium and the mechanic model of continuous medium equivalent to jointed rock mass,the equivalent and statistically equivalent models of jointed rock mass are used to discuss the elastic modulus and the stress field in parent rock,both are computed inversely through the back FEM analysis of displacement.By back parametric analysis,the influences of the joint of rock mass and heterogeneity on the results of back analysis of displacement are further discussed.A conclusion is thus drawn that if the mechanic model of continuous medium equivalent to jointed rock mass is based on assumption,using different mechanic models has comparatively obvious influence on the elastic modulus computed inversely.While the heterogeneity of mechanic parameters of jointed rock mass has slight influence on the inversely computed stress field in parent rock.It implies that the assumption of homogeneity or isotropy is applicable to measuring the stress field in parent rock and back analysis of displacement.