微裂隙基岩体扰动荷载-腐蚀耦合诱发灾害机理与双重疲劳损伤特性研究

Slope landslide, collapse, failure of bedrock disturbance and other geological disasters are often caused by the coupling effect of corrosion fatigue and mechanical fatigue. Preparation process of the disaster is researched under the action of coupling effect of the disturbance and corrosion from the perspective of nonlinear science and experimental science. The environmental driving factor is introduced into the catastrophe theory, and the essence and mechanism of disaster are analyed deeply to extend the past simple thought of disturbance disasters research from the angle of mechanics only. The function relation between the environmental driving factor of the three types of induced disaster mode and disturbance frequency, amplitude, ion concentration and pH is determined on the base of test. The fatigue damage mode, damage mechanism and failure law of microfracture bedrock are revealed in different coupling environment. Double fatigue damage model of disturbance load-corrosion coupling and the control equations are established based on the theory analysis and test results, and to find an appropriate coupling solving method. The dynamic response and damage evolution are analyed with the complie solving program. The results will help to know the induced disasters mechanism of microfracture bedrock in complex environment, and further improve the multi-field coupling theory of rock. Deeped the understanding of evolution process of the slope landslide, collapse and other disasters, and provide scientific theoretical basis for prediction and prevention of disaster in the construction of the underground engineering.

自然界边坡滑坡、崩塌以及基岩体扰动破坏等地质灾害的发生往往是由腐蚀疲劳和机械疲劳耦合作用引起的，为研究扰动与腐蚀耦合效应对灾害孕育过程的作用，从非线性科学和试验科学的角度出发，引入环境驱动因子到突变理论之中，从理论上深入分析灾害发生的本质和机理，拓展以往单纯从力学角度研究扰动诱发灾害的思路；基于试验确定三种诱发灾害模式下环境驱动因子与扰动频率、幅值、离子浓度及pH值等因素的函数关系式，揭示不同耦合环境下微裂隙基岩体的疲劳损伤模式和机理、破坏规律；在上述理论分析和试验结果的基础上，建立扰动荷载-腐蚀耦合双重疲劳损伤模型和控制方程，并寻求一种合适的耦合求解方法，进行实际工程的动力响应与损伤演化分析。研究成果将有助于深层次分析复杂环境的致灾机理，进一步丰富岩石多场耦合理论体系，加深对自然界边坡滑坡、崩塌等灾害孕育演化过程的认识，以及为地下空间等工程修建中的灾害预测和防治提供科学的理论基础。

自然界边坡滑坡、崩塌、泥石流以及基岩开挖扰动破坏等地质灾害的发生，往往是由环境水腐蚀和机械疲劳两种因素联合作用引起的。关于微裂隙基岩体在水化学腐蚀、扰动荷载耦合环境下的致灾机理及双重疲劳损伤研究具有重要科学意义。重点聚焦于考虑扰动荷载与腐蚀耦合诱发灾害的机制，尤其在这种复杂环境下的双重疲劳损伤特性。自主设计并研制岩石水化学腐蚀试验系统和突水模型试验系统，为开展复杂动力扰动与水化学腐蚀耦合环境试验和灾害预测提供新的测试手段。基于试验数据拟合不同腐蚀时间下岩石疲劳寿命预测N-T曲线，可以用来预测耦合作用下岩石的疲劳寿命。立足于岩石材料的非线性变形机制，建立了基于Mohr-Coulomb屈服准则的弹塑性损伤模型，推导了弹塑性损伤本构方程的主应力空间隐式返回映射算法，从主应力空间角度出发解决“奇异性”问题，同时也为进一步研究岩石材料的非线性特征奠定基础。基于广义双T2强度理论建立非关联流动的弹塑性本构模型，并推导完全隐式本构积分算法，丰富了岩石强度理论。基于试验和理论分析，建立微裂隙基岩体扰动荷载-腐蚀耦合的双重疲劳损伤模型，并提出一种合适的耦合数值求解方法，从非线性科学的角度深入分析基岩体扰动-腐蚀耦合致灾机理。研究拓展了以往单纯从力学角度研究扰动诱发灾害的思路，揭示不同耦合环境下微裂隙基岩体的耦合疲劳损伤机理和规律，将有助于深层次分析复杂环境的致灾机理，进一步丰富岩石多场耦合理论体系，对自然界边坡滑坡、崩塌的认识以及地下空间等工程修建、灾害机理分析和防治提供科学的理论基础。