考虑局部胶结破损热力学行为的结构性黄土二元介质本构模型  

A binary medium model for structural loess considering thermodynamic behavior of local bonding broken process

作　　者：王番[1] 郅彬[1] 刘恩龙[2] 王小婵 邓博团[1] 李金华[1] 张辉[1] WANG Pan;ZHI Bin;LIU En-long;WANG Xiao-chan;DENG Bo-tuan;LI Jin-hua;ZHANG Hui(School of Architecture and Civil Engineering,Xi’an University of Science and Technology,Xi’an,Shaanxi 710054,China;College of Water Resources and Hydropower,Sichuan University,Chengdu,Sichuan 610065,China;College of Geological Engineering and Geomatics,Chang’an University,Xi’an,Shaanxi 710054,China)

机构地区：[1]西安科技大学建筑与土木工程学院,陕西西安710054 [2]四川大学水利水电学院,四川成都610065 [3]长安大学地质工程与测绘学院,陕西西安710064

出　　处：《岩土力学》2025年第1期97-109,共13页Rock and Soil Mechanics

基　　金：陕西省自然科学基金一般项目——青年基金(No.2024JC-YBQN-0258);兵团青年科技创新人才项目(基础研究)(No.2023CB008-28);陕西省重点研发计划一般项目——社会发展领域(No.2023-YBSF-506)。

摘　　要：建立考虑局部胶结破损机制的本构模型是黄土力学核心任务之一,是解决黄土工程稳定性分析/评价的关键理论基础。基于热力学方法和岩土破损力学,建立了一个宏-细观热力学本构模型,它能够定量描述局部胶结破损的热力学行为及细观尺度应力-应变非均匀分布特征,提高了模型对变形的预测精度,其在数学形式上同剑桥模型类似。首先,通过热力学能量守恒定律,确定结构性黄土压缩变形过程中的结构破损功数学表达式,并发现结构性黄土局部损伤耗散的热力学行为主要来源:(1)破损集合体与未破损集合体之间的相互摩擦作用;(2)未破损集合体向破损集合体转换时,部分细观结构破损的不可逆热力学行为。基于此认识,建立了考虑胶结破损热力学行为的宏-细观本构模型框架,并通过分析结构性黄土变形机制(摩擦+胶结+破损共同作用),确定其自由能、耗散能和破损耗散能表达式;推导了一个考虑体积破损和剪切破损演化规律的损伤屈服函数及本构关系。通过所建立本构关系对已有试验数据进行预测,验证其合理性。Establishing a constitutive model that reflects the local bonding breakage process has always been a core task in soil mechanics and is crucial for solving engineering stability issues.Based on thermodynamic principles and breakage mechanics,this paper proposes a macro-micro thermodynamic constitutive model.This model quantitatively describes the thermodynamic behavior of local bonding breakage and the non-uniform distribution of stress-strain at the microscale.It improves the prediction accuracy of the model for deformation characteristics,which is similar to the Cambridge model in mathematical form.Firstly,based on the law of conservation of thermodynamic energy,the mathematical expression of structural breakage work during compression deformation was determined.It was found that the dissipated energy of breakage can be mainly divided into two parts:the frictional effect between bonded elements and frictional elements,and the irreversible transformation from bonded elements to frictional elements.Furthermore,a macro-micro constitutive model framework considering the thermodynamic behavior of local bonding breakage was established.Secondly,based on the constitutive framework and the deformation mechanism of loess(frictional,bonded,and damaged),the expressions for free energy,dissipated energy,and damage dissipated energy were determined.The damage yield function and elastic-plastic constitutive model considering the evolution laws of volume breakage and shear breakage were derived.Finally,the established model was used to predict the experimental data of other scholars,and its rationality and simulation advantages were verified through comparison.This model aligns better with thermodynamic principles,and its parameters are easy to determine.

关 键 词：结构性黄土 本构模型 局部破损 热力学 二元介质模型 

分 类 号：TU411[建筑科学—岩土工程]