岩土力学2024，Vol.45Issue(3)：674-684,11.DOI:10.16285/j.rsm.2023.1063
分级动荷载下土石混合体滞回曲线形态特征试验研究
Morphological characteristics of hysteretic curves of soil-rock mixture under stepped axial cyclic loading
摘要
Abstract
The strata in urban backfill areas mostly exist in the form of loose soil-rock mixture,with high structural porosity,low strength,and poor engineering performance.They are sensitive to dynamic loads such as tunnel construction disturbance and subway train operation.The hysteretic curve can reflect the deformation,stiffness and energy dissipation of soil under dynamic load.It is of great significance to study the hysteretic curve of soil-rock mixture for the construction and operation safety of subway in backfill area.Using KTLDYN servo-controlled dynamic triaxial test system,the cyclic load test on soil-rock mixture samples in backfill area was carried out by means of cyclic loading.The effects of stone content(P),water content(ω),consolidation stress ratio(kc)and loading frequency(f)on the morphological characteristics(including adjacent center spacing(d),long axis slope(k),enclosing area(S)and degree of non-closure(εp))and backbone curves of hysteretic curves are investigated.The results show that the typical hysteretic curves of soil-rock mixture are in long fusiform shape on the whole,with pointed lobes at both ends.With the increase in vibration level,d,S and εp increase nonlinearly,while k decreases logarithmically.For the same vibration level,d and εp decrease with the increases of P,kc and f,and first decrease and then increase with the increase of ω k increases with the increases of P,kc and f,and increases first and then decreases with the increase of ω.S is positively correlated with P,increasing first and then decreasing with the increase of ω,and decreasing with the increases of kc and f.The dynamic stress and slope of backbone curve increase with the increases of P,kc and f when the dynamic stress variation is the same,and they first increase and then decrease with the increase of ω.关键词
土石混合体/动三轴试验/滞回曲线/骨干曲线/动力特性Key words
soil-rock mixture/dynamic triaxial test/hysteretic curve/backbone curve/dynamic property分类
建筑与水利引用本文复制引用
黄锋,米吉龙,杨永浩,董广法,张班,刘星辰..分级动荷载下土石混合体滞回曲线形态特征试验研究[J].岩土力学,2024,45(3):674-684,11.基金项目
重庆市自然科学基金面上项目(No.CSTC2020JCYJ-MSXMX0679,No.CSTB2022NSCQ-MSX0497) （No.CSTC2020JCYJ-MSXMX0679,No.CSTB2022NSCQ-MSX0497）
山区桥梁及隧道工程国家重点实验室开放基金(No.SKLBT-19-006,No.SKLBT-YF2106) （No.SKLBT-19-006,No.SKLBT-YF2106）
重庆市教委科学技术研究项目(No.KJQN202100717) （No.KJQN202100717）
国家自然科学基金资助项目(No.52078090).This work was supported by the Project of Chongqing Natural Science Foundation(CSTC2020JCYJ-MSXMX0679,CSTB2022NSCQ-MSX0497),the Open Fund of State Key Laboratory of Mountain Bridge and Tunnel Engineering(SKLBT-19-006,SKLBT-YF2106),the Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN202100717)and the National Natural Science Foundation of China(52078090). （No.52078090）
