基于Lade-Duncan和SMP两种强度准则的岩石残余应力研究

STUDY OF RESIDUAL STRESS OF ROCK BASED ON LADE-DUNCAN AND SMP STRENGTH CRITERIA

首先利用平面强度理论推导出基于Lade-Duncan和SMP两种准则的强度统一表达式,并结合岩石材料峰后应变软化的力学特性,以峰后内摩擦角为中间变量,用残余应变来表示峰后非线性弹性模量E,最后建立岩石峰后残余应力的统一非线性本构方程(即峰后本构模型)。结合小官庄铁矿东区典型破裂岩闪长玢石的三轴试验,对该试验结果进行不同围岩下峰后应力-应变关系的模拟计算。结果表明,建立的峰后本构关系能较好地模拟试验结果,从而验证该模型的合理性,为研究岩石峰后力学规律提供新的途径。

By using plane strength theory, unified strength formula based on the spatially mobiliaed plane（SMP） and Lade-Duncan criteria is derived. Combining with post-peak rock material mechanical properties of post-peak strain softening, considering post-peak internal friction angle tp as intermediate variables, residual strain e is used to express the post-peak nonlinear elastic modulus E, and finally a unified nonlinear constitutive equation which can be also named as constitutive model of rock post-peak residual stress is established. Combining with triaxial test of typical fractured diorite porphyrite in Eastern area of Xiaoguanzhuang iron mine, simulated calculation of post-peak stress-strain relationship curves for different confining pressures by this model is conducted. The result shows that the post-peak constitutive relation of this study can simulate the experimental results well, so as to prove the rationality of the model and providing a new way to study the post-peak mechanical regular pattern of rock.