岩土力学2024，Vol.45Issue(1)：49-58,67,11.DOI:10.16285/j.rsm.2023.0162
热-力耦合作用下垃圾土体积变形特性和模型研究
Thermo-mechanical volume change behavior and constitutive model of municipal solid waste
摘要
Abstract
The internal temperature of municipal solid waste(MSW)landfills is chronically higher than the ambient temperature due to heat production from organic matter degradation,which leads to engineering operation and maintenance problems.Existing experimental results show that the thermally induced volume changes of MSW were stress dependent and the elastic volumetric strain was significant,the latter may affect the determination of plastic volumetric strain which is usually used as the hardening parameter of constitutive model.On the basis of the previous tests,the effect of temperature on the volumetric deformation and compression characteristics of the clay in MSW under drained conditions were investigated by using the GDS temperature-controlled stress path triaxial apparatus,and the results were compared with the volumetric deformation characteristics of MSW under the same conditions to reveal the influencing mechanism of temperature change on the volumetric deformation characteristics of MSW.The methods of determining the thermal elastoplastic compression index λT and thermal elastic compression index κT of MSW were derived based on the results of MSW temperature-controlled triaxial tests.By adopting the principle of equivalent stress and assuming that the elastoplastic volumetric strain induced by temperature change was equal to the elastoplastic volumetric strain induced by an equivalent stress increment,a computational model for the volumetric deformation of MSW under thermo-mechanical coupling effect was established,and the model was validated and analyzed.The results showed that the void ratio was the main factor affecting the thermal volumetric strain of MSW.The λT and κr of MSW reduced with the increase of the initial consolidation stress,which were one order of magnitude larger than those of clay.The ratio of compression index λ and swelling index κ(κ/λ)at the corresponding consolidation stress level and normal temperature could be selected to simulate the volumetric deformation characteristics of MSW under thermo-mechanical coupling effects.关键词
垃圾土/热-力耦合作用/体积变形/弹性体积应变/塑性体积应变Key words
municipal solid waste(MSW)/coupled thermo-mechanical effect/volumetric deformation/elastic volumetric strain/plastic volumetric strain分类
建筑与水利引用本文复制引用
李玉萍,陈嘉瑞,施建勇,樊宝云..热-力耦合作用下垃圾土体积变形特性和模型研究[J].岩土力学,2024,45(1):49-58,67,11.基金项目
国家自然科学基金青年基金项目(No.41702290) （No.41702290）
国家自然科学基金面上项目(No.42277134).This work was supported by the Youth Fund of National Natural Science Foundation of China(41702290)and the General Fund of the National Natural Science Foundation of China(42277134). （No.42277134）
