一种考虑主应力空间特性的岩石强度准则  

A rock strength criterion considering spatial properties of principal stresses

作　　者：黄家军 李斌[2] 王鹏 HUANG Jiajun;LI Bin;WANG Peng(Science and Technology Bureau of Yongqiao District,Suzhou,Anhui 234000,China;School of Environment and Resources,Southwest University of Science and Technology,Mianyang,Sichuan 621010,China)

机构地区：[1]宿州市埇桥区科学技术局,安徽宿州234000 [2]西南科技大学环境与资源学院,四川绵阳621010

出　　处：《岩石力学与工程学报》2024年第1期157-169,共13页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51904248)。

摘　　要：基于现有岩石材料的主应力空间破坏曲面特征理论和试验结果,针对传统强度准则参数多且物理意义不明确的问题,通过分析常规三轴抗压强度曲线在双向等拉应力点(0,σtt,σtt)的变化特点,提出强度曲线在双向等拉应力点存在d(σ1-σ3)/dσm=3的观点,同时建立含双向等拉强度σtt和三向等拉强度σttt这2个参数的双曲线型强度准则,该强度准则同时考虑了平均应力效应对子午线和π平面上强度曲线的影响,参数物理意义明确。为验证其合理性与适用性,利用该强度准则对以往研究中的14种岩石三轴试验数据进行拟合计算,并与拟合精度较高的Burzynski抛物线准则和尤明庆指数准则进行对比分析。结果表明,不论是针对常规三轴还是真三轴试验数据,该准则拟合效果都比较好,相关系数均在0.99以上,且拟合得出的双向等拉强度σtt和三向等拉强度σttt大小在合理范围内;同时,不同约束条件下的拟合结果也印证了在双向等拉应力点(0,σtt,σtt)存在d(σ1-σ3)/dσm=3的观点。说明该准则的合理性与适用性较好,可为岩石工程领域提供一定的实践指导价值。Based on the existing theories and experimental conclusions on the spatial damage surface characteristics of the principal stresses of rock materials,and in response to the problem that the conventional strength criterion has many parameters and the physical significance is not clear,it is put forward that there exists a strength curve in the bi-directional isotropic tensile stress point with the point of view that d(σ1-σ3)/dσm=3,by analyzing the characteristics of the change of the conventional triaxial compressive strength curves in the bi-directional isotropic tensile stress point(0,σtt,σtt).Meanwhile,a hyperbolic-type strength criterion containing two parameters of two-way isotropic tensile strengthstt and three-way isotropic tensile strengthsttt is established,which takes into account both the average stress effect on the strength curves on the meridian and theπ-plane,and the parameters have clear physical meanings.In order to verify its reasonableness and applicability,the strength criterion was utilized to fit and calculate the triaxial test data of 14 types of rocks in the published literature,and compared and analyzed with Burzynski¢s parabolic criterion and You Mingqing¢s exponential criterion,which have higher fitting accuracy.The results show that the fitting effect of this criterion is better for both conventional triaxial test data and true triaxial test data,with the correlation coefficients above 0.99,and the sizes of the fitted bidirectional isotropic tensile strengthsstt and the three-directional isotropic tensile strengths σttt are in a reasonable range;at the same time,the fitting results under different constraints corroborate the idea that there exists d(σ1-σ3)/dσm=3 at the bidirectional equal tensile stress points(0,σtt,σtt).It shows that the criterion is reasonable and applicable,and can provide some practical guidance value for the field of rock engineering.

关 键 词：岩石力学 主应力空间 强度准则 双向等拉应力点 双曲线 平均应力效应 

分 类 号：TU45[建筑科学—岩土工程]