深表土复杂应力下人工冻土蠕变损伤耦合本构模型研究

项目名称： 深表土复杂应力下人工冻土蠕变损伤耦合本构模型研究

项目编号： No.50804002

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 李栋伟

作者单位： 安徽理工大学

项目金额： 20万元

中文摘要： 采用试验研究、理论分析和数值模拟相结合的方法对深表土（500m以下）人工冻结粘土本构关系进行研究。研究内容如下：（1）不同温度、不同应力路径的三轴试验研究，获得冻土屈服准则、应力应变关系、冻土蠕变强度包络线分布规律和蠕变方程；（2）冻土微观（S250-2型扫描电镜）损伤试验研究，获得人工冻结粘土的损伤演化方程；（3）基于热力学原理和统计损伤理论建立冻土粘弹塑损伤耦合本构方程，以及模型中确定本构参数的试验方法研究；（4）将提出的冻土粘弹塑损伤耦合本构模型通过用户子程序嵌入到有限元软件ADINA中；（5）基于有限元和遗传算法理论编制参数反演程序，对实际工程进行数值模拟，建立的冻土本构模型进行参数辨识；（6）通过现场实测和数值模拟检验冻土蠕变损伤耦合本构模型的正确性。 课题开展为进一步研究现场的冻土力学行为及破坏特征提供了有效的研究途径，可为深井冻结壁设计、稳定性分析和工程预测提供科学指导。

中文关键词： 冻粘土；蠕变；损伤；本构关系；参数辨识

英文摘要： The comprehensive method of experimental investigation, theoretical analysis and numerical simulation is adopted in this subject. Based on the triaxial experimental results of frozen soil, theological mechanical properties of frozen soil are made a detailed discussion by non-linear and damage mechanics theory, which investigates mainly the theological mechanical properties of frozen soil with diferent confiningm pressures and temperature under saturated state. And then non-linear theology constitutive model coupled damage of frozen soil is proposed. The main investigation work focuses on the following: (1)With W3Z-200 servo-controlled testing machine,triaxial experiment is performed for frozen soil yield criterion,stress-strain relationship,creep type failure envelopes and creep equation of frozen soil in different temperature and stress path. (2)Experimental studying of the damage of frozen soil is carried out for damage evolution equation of frozen soil by using SEM. (3)Based on the analysis of non-linear creep damage properties of forzen soil,a creep damage-coupling constitutive model,which can reflect the accelerative creep property, is put forward by adopting thermomechanics principle and statistical damage theory. (4)The creep damage-coupling model is embedded in ADINA finite element program on the base of secondary developing technique for finite element program. (5)Based on the displacement time series from field monitoring，rheological parameter of frozen soil is obtained with numerical inversion analysis method，and visco-elastic constitutive model for squeezing frozen soil is identified inengineering practice． (6)Theoretical and experimental studying result is applied to the engineering practice of frozen soil construction,the long-term stability of frozen soil engineering under complex stress state is predicted,which brings forward reasonable evalution and suggestion for long-term stability and safety of frozen soil engineering.

英文关键词： frozen cohesive soil;creep;statistical damage;constitutive equation;