Abstract The capacity for self-healing of fractures in geomaterials, especially clay, is a well-documented phenomenon that is important in many problems encountered in geotechnical and geo-environmental engineering (e.g., foundation design, slope stability, waste barrier systems, hydraulic fracturing). Several constitutive models that can account for damage and fracture of geomaterials have been proposed, many of which are formulated at microstructural scale with high computational costs that often preclude them from usage in engineering practice. In addition, mechanical constitutive laws describing healing (i.e., damage reversal) have been mainly developed for concrete and rock but not for soil. A coupled elastoplastic-damage-healing constitutive model is presented in this paper to investigate the behaviour of geomaterials subjected to hydro-mechanical loadings. The mathematical formalism is presented within a continuum mechanics framework, with damaged-healed configuration defined through an energy equivalence hypothesis. Damage and healing evolution laws are also established within the framework of thermodynamics, taking into account the effect of plastic hardening, strain rate, stress ratio, suction hardening as well as confining pressure. The elastoplastic response of geomaterials is captured using a bounding surface plasticity model from critical state soil mechanics. Effects of damage, healing and suction are also accounted for by defining a proper hardening rule based on the consistency condition. The presented model's ability to simulate experimental results taken from the literature is assessed. Several examples are solved under different loading conditions in order to study the effect of damage-healing on the behaviour of unsaturated soils.

中文翻译：

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基于热力学的非饱和岩土材料弹塑性损伤-愈合耦合模型

摘要 岩土材料（尤其是粘土）中裂缝的自愈能力是一种有据可查的现象，在岩土工程和地质环境工程中遇到的许多问题（例如，基础设计、边坡稳定性、废物屏障系统、水力压裂）中都很重要。 ）。已经提出了几种可以解释岩土材料损坏和断裂的本构模型，其中许多是在微观结构尺度上制定的，计算成本很高，这通常使它们无法在工程实践中使用。此外，描述愈合（即损伤逆转）的机械本构定律主要是针对混凝土和岩石而不是土壤开发的。本文提出了一个耦合的弹塑性-损伤-愈合本构模型，以研究土工材料在流体力学载荷下的行为。数学形式是在连续介质力学框架内提出的，具有通过能量等价假设定义的受损愈合配置。损伤和愈合演化规律也在热力学框架内建立，考虑到塑性硬化、应变率、应力比、吸力硬化以及围压的影响。使用临界状态土壤力学的边界表面塑性模型捕获土工材料的弹塑性响应。通过基于一致性条件定义适当的硬化规则，还可以考虑损坏、愈合和抽吸的影响。提出的模型' 评估了模拟从文献中获取的实验结果的能力。为了研究损伤修复对非饱和土的行为的影响，在不同的加载条件下解决了几个例子。