冻结饱水砂卵石蠕变损伤特性试验研究  

Experimental Research on the Creep Damage Characteristics of Frozen Saturated Sandy Gravel

作　　者：张晋勋[1] 宋永威 杨昊[1] 张雷[1] 亓轶 ZHANG Jin-xun;SONG Yong-wei;YANG Hao;ZHANG Lei;QI Yi(Postdoctoral Workstation, Beijing Urban Construction Group Co., Ltd., Beijing 100088, China)

机构地区：[1]北京城建集团有限责任公司博士后工作站,北京100088

出　　处：《科学技术与工程》2021年第29期12665-12671,共7页Science Technology and Engineering

基　　金：北京市科学技术委员会资助项目(Z161100001116088);北京市博士后工作经费资助项目(2020-22-086)。

摘　　要：以北京典型饱水砂卵石地层为研究对象,基于损伤演化及元件模型理论,引入弹性体、黏壶体及损伤体,建立了Ⅰ、Ⅱ类蠕变损伤模型,并通过-10℃条件下饱和砂卵石的三轴蠕变试验对该模型进行了验证。研究表明:当应力差较小时,蠕变主要以瞬时弹性变形为主,均大于该阶段总变形量的57.62%,随着应力差的增大,蠕变以非线性变形为主;蠕变进入加速破坏阶段的应变均大于7.16%;围压为0~0.3 MPa时,冻结砂卵石的长期强度在2~3 MPa,围压为0.6~1 MPa时,长期强度在3~4 MPa,冻结砂卵石的长期强度为瞬时强度的0.23~0.42倍;引入损伤体建立的蠕变损伤模型可以较好地反映冻结砂卵石的Ⅰ、Ⅱ类蠕变规律,可为工程设计及数值模拟提供理论基础。Taking Beijing's typical saturated sandy gravel stratum as the research object,based on the damage evolution and element model theory,classⅠandⅡcreep damage models were established by introducing elastomer,clay pot and damaged body.The model was verified by triaxial creep test of saturated sandy pebbles at-10℃.Studies have shown that when the stress difference is small,the creep deformation is dominated by instantaneous elastic deformation,which is greater than 57.62%of the total deformation at this stage.With the increase of the stress difference,the creep is dominated by nonlinear deformation.The strain entering the accelerated failure stage is greater than 7.16%.When the confining pressure is 0~0.3 MPa,the long-term strength of frozen sandy gravel is 2~3 MPa,and when the confining pressure is 0.6~1 MPa,the long-term strength is in the range of 3~4 MPa,and the long-term strength of the frozen sandy gravel is about 0.23~0.42 times of the instantaneous strength.The creep damage model established by introducing the damage body can well reflect the typeⅠandⅡcreep change law of frozen sandy gravel,which can provide practical engineering design and numerical simulation with theoretical basis.

关 键 词：饱水砂卵石 蠕变 蠕变损伤模型 长期强度 

分 类 号：TU443[建筑科学—岩土工程]