冻融损伤石英岩力学特性及损伤本构模型  

Mechanical Characteristics and Damage Constitutive Model of Quartzite under Freeze-thaw Cycles

作　　者：侯召旭 刘先峰[1,2,3] 王通 张俊 袁胜洋[1,2] 胡金山[4] HOU Zhao-xu;LIU Xian-feng;WANG Tong;ZHANG Jun;YUAN Sheng-yang;HU Jin-shan(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Key Laboratory of High-Speed Railway Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China;School of Civil Engineering,Xinjiang Institute of Engineering,Urumqi 830023,China;China Railway First Survey and Design Institute Group Co.,Ltd.,Xi’an 710043,China)

机构地区：[1]西南交通大学土木工程学院,成都610031 [2]西南交通大学高速铁路线路工程教育部重点实验室,成都610031 [3]新疆工程学院土木工程学院,乌鲁木齐830023 [4]中铁第一勘察设计院集团有限公司,西安710043

出　　处：《长江科学院院报》2025年第1期177-185,共9页Journal of Changjiang River Scientific Research Institute

基　　金：国家自然科学基金项目(52078432,52168066);中央引导地方科技发展专项(ZYYD2023B02);中铁第一勘察设计院集团有限公司科研项目(院科-20-06)。

摘　　要：西南艰险山区分布有大量岩质边坡,长期冻融作用引起岩体力学性能发生劣化,进一步导致边坡稳定性降低。为研究岩体在冻融作用下的损伤劣化规律,选取某高陡边坡工程的低孔隙率石英岩进行不同冻融循环次数条件下的单轴压缩试验,分析其力学劣化和能量演化规律,并基于能量演化规律提出岩石完全压密点的确定方法,以完全压密点为分段点建立考虑压密段的岩石分段损伤本构模型。研究结果表明:前期冻融循环作用对石英岩的影响较小,当冻融循环次数>40时,石英岩的力学性能出现明显劣化,破坏模式由剪切破坏逐渐向拉-剪复合破坏转变;确定弹性能耗比K(耗散能/弹性应变能)为1.2对应的点为完全压密点,压密应变随冻融循环次数的增加呈线性增大;考虑压密段的岩石分段损伤本构模型与试验数据的匹配度较好,可更准确地描述冻融损伤石英岩的变形破坏特性。There are a large number of rock slopes in the difficult and dangerous mountainous areas of southwest China.Long-term freeze-thaw action deteriorates the mechanical properties of the rock mass,leading to decreased slope stability.To study the damage degradation law of rock mass under freeze-thaw action,uniaxial compression tests were conducted on low-porosity quartzite from a high and steep slope in the southwest hazardous mountainous area.The mechanical deterioration and energy evolution were analyzed.Based on the energy evolution law,a method for determining the complete compaction point of rock was proposed.A piecewise damage constitutive model of the rock in consideration of the compaction section was established by taking the complete compaction point as the piecewise point.Results show that early freeze-thaw cycles have little effect on the quartzite.However,when the number of freeze-thaw cycles exceeds 40,the mechanical properties of quartzite deteriorate significantly,and the failure mode gradually changes from shear failure to a combination of tensile and shear failure.The point corresponding to an elastic energy consumption ratio K(ratio of dissipated energy to elastic energy)of 1.2 is determined as the complete compaction point.The strain corresponding to the complete compaction point increases linearly with the increase in freeze-thaw cycles.The proposed piecewise damage constitutive model matches well with experimental data and more accurately describes the deformation and failure characteristics of freeze-thaw damaged quartzite.

关 键 词：冻融循环 石英岩 力学劣化 能量演化 完全压密点 分段损伤本构模型 

分 类 号：TU452[建筑科学—岩土工程]