基于能量释放理论的丹东滨海湿地黏性冻土本构模型

Constitutive Model of Viscous Frozen Soil in Dandong Coastal Wetland Based on Energy Release Theory

丹东滨海湿地黏性冻土结构复杂,受温度、应力等因素影响,该地带工程竣工后易产生路面不均匀沉降等问题。为此,建立基于能量释放理论的三轴本构模型。为了描述不同温度、围压交互耦合作用下黏性冻土的应力-应变变化规律,采用MTS815试验系统对黏性冻土开展力学特性试验,分析温度、围压对能量演化规律的影响,并结合能量释放理论对传统本构模型进行修正。结果表明:基于能量释放率应力-应变关系的本构计算值与试验值有着良好的吻合度,二者相关系数均在0.95以上,拟合数据和试验数据趋于一致。

The structure of viscous frozen soil in Dandong coastal wetland is complex.Affected by temperature,stress and other factors,the uneven settlement of the road surface is easy to occur in this area after the completion of the project.Therefore,a three-axis constitutive model based on energy release rate was proposed.In order to describe the stress-strain change law of viscous frozen soil under the interaction of different temperature and confining pressure,the mechanical properties of cohesive frozen soil were tested by MTS815 test system.The influence of temperature and confining pressure on energy evolution law was analyzed,and the traditional constitutive model was modified by energy release theory.The results show that the calculated values based on the stress-strain relationship of energy release rate are in good agreement with the experimental values,and the correlation coefficients between the calculated values and the experimental values are all above 0.95.The model curve and the experimental data fit well.