摘要
延安新区填方工程是目前我国黄土地区规模最大的治沟造地工程之一。考虑到填方土体的蠕变特性导致填方工程长期变形量的问题,采用分级增量循环加卸荷方式,对延安新区压实黄土进行了不同基质吸力下的三轴固结不排水蠕变试验,得到了压实黄土的蠕变加卸荷曲线。试验结果表明,不同基质吸力下土样的蠕变特性不同,在低应力、较高应力水平下呈现衰减蠕变和稳定蠕变特性,在高应力水平下呈现加速蠕变特性;卸荷应力水平及基质吸力对土体卸荷回弹变形有一定影响;加卸荷应力历史对土样的蠕变变形具有累积效应。通过引入村山体和非线性粘性体,建立了适用于延安新区压实黄土的三维蠕变本构模型。
Yan'an New District filling project is one of the largest gully management and land reclamation projects in loess area of China.Considering the long-term deformation caused by the creep characteristics of the filling soil,the triaxial consolidated undrained creep tests of compacted loess in Yan'an New District under different matric suction were carried out by means of graded incremental cyclic loading and unloading,and the creep loading and unloading curves of compacted loess were obtained.The test results show that the creep characteristics of soil samples are different under different matric suction,showing attenuation creep and stable creep under low stress and high stress level,and accelerating creep under high stress level;unloading stress level and matric suction have certain influence on unloading rebound deformation of soil.The loading and unloading stress history has a cumulative effect on the creep deformation of soil samples.A three-dimensional creep constitutive model of compacted loess in Yan'an New District is established by introducing village hill body and nonlinear viscous body.
作者
单帅
谢婉丽
朱荣森
杨惠
SHAN Shuai;XIE Wanli;ZHU Rongsen;YANG Hui(State Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xifan 710069,China)
出处
《干旱区资源与环境》
CSSCI
CSCD
北大核心
2021年第7期144-155,共12页
Journal of Arid Land Resources and Environment
基金
国家自然科学基金项目(41772323,41972292)
陕西省国际科技合作计划重点项目(2019KWZ-02)
国家重点研发计划项目(2017YFD0800501)资助。
关键词
压实黄土
三轴蠕变试验
加速蠕变
本构模型
remolded loess
triaxial creep test
accelerated creep
constitutive model
