多孔岩体蠕变诱发延迟压实局部化失稳特性  

Characteristics of Delayed Compaction Localization Instability of Porous Rocks

作　　者：薛大为 吕玺琳[1,2] 任中俊[3] 刘泳钢[4] XUE Dawei;LYU Xilin;REN Zhongjun;LIU Yonggang(Key Laboratory of Geotechnical and Underground Engineering of the Ministry of Education,Tongji University,Shanghai 200092,China;College of Civil Engineering,Tongji University,Shanghai 200092,China;School of Civil Engineering,Hunan University of Science and Technology,Xiangtan 411201,Hunan,China;Sichuan Academy of Architectural Sciences,Chengdu 610084,China)

机构地区：[1]同济大学岩土及地下工程教育部重点实验室,上海200092 [2]同济大学土木工程学院,上海200092 [3]湖南科技大学土木工程学院,湖南湘潭411201 [4]四川省建筑科学研究院,四川成都610084

出　　处：《同济大学学报（自然科学版）》2021年第11期1539-1545,共7页Journal of Tongji University:Natural Science

基　　金：国家自然科学基金(41672270);四川省科技计划(21SYSX0129);交通运输行业重点科技项目(2019-ZD5-026)。

摘　　要：针对多孔岩体蠕变诱发的延迟压实局部化失稳问题,提出了一种基于弹黏塑性及可控性理论的压实局部化失稳判别准则。通过构建局部常微分方程系统,定义定常外部摄动条件下的弹黏塑性本构算子,用于识别自发传播压实局部化带内的不稳定加速变形。通过检查方程系统的可控性损失,得出了多孔岩体压实局部化的失稳指数。基于弹黏塑性本构模型,分析了平面应变条件下多孔岩体中的拟瞬时和延迟压实局部化,对所提出的失稳指数进行验证。进一步地,利用有限元数值模拟,验证了该失稳指数在分析边值问题中延迟压实局部化失稳的适用性。To assess creep-induced delayed compaction localization in rate-dependent porous rocks,a theoretical criterion for compaction localization is proposed based on elastic-viscoplasticity and the theory of controllability.By establishing systems of local ordinary differential equations,the elastic viscoplastic constitutive operator is defined under the stationary external perturbation condition to identify the unstable acceleration deformation inside the spontaneously propagating strain localized bands.By detecting the loss of controllability in the systems,an instability index for compaction localization in rate-dependent porous rocks is derived.The proposed index is verified by simulating the quasi-instantaneous and delayed compaction localization in a porous rock based on the viscoplastic constitutive model.Furthermore,the applicability of the proposed index in analyzing delayed compaction localization in boundary value problems is validated by using finite element simulation of plane strain compression tests.

关 键 词：压实局部化 材料失稳 蠕变 弹黏塑性 

分 类 号：TU443[建筑科学—岩土工程]