冻融循环作用下砂岩无损测试力学特性研究  

Study on the mechanical properties of sandstone nondestructive testing under the freeze-thaw cycle

作　　者：刘杰[1] 黎照 杨渝南[1] 唐洪宇 高进 沈豪炜 LIU Jie;LI Zhao;YANG Yunan;TANG Hongyu;GAO Jin;SHEN Haowei(Key Laboratory of Geological Hazards on Three Gorges Reservoir Area,Ministry of Education,China Three Gorges University,Yichang 443002,China)

机构地区：[1]三峡大学三峡库区地质灾害教育部重点实验室

出　　处：《水资源与水工程学报》2019年第4期201-209,216,共10页Journal of Water Resources and Water Engineering

基　　金：国家自然科学基金项目(51439003、51579138);国家科技支撑计划项目(2015BAB07B08);成都理工大学地质灾害防治与地质环境保护国家重点实验室开放基金项目(SKLGP2016K023);湖北省自然科学基金杰出青年人才计划项目(2018CFA065);三峡大学拔尖人才计划项目(KJ2014H012);三峡大学硕士学位论文培优基金项目(2019SSPY025)

摘　　要：针对冻融循环作用下砂岩冻融损伤机理和物理力学参数之间相互关系的问题,利用5种可重复操作的无损检测法(电阻测试、声波测试、滴定测试、CT扫描、局部细观放大技术)对低应力循环荷载作用下冻融循环试验后的岩样进行检测,并对岩样的冻融劣化机理作出了分析,通过CT扫描得到岩样CT数值变化规律并发现冻融作用,找出了冻融后参数间的关系。结果表明:岩样物理参数和动力力学参数对冻融作用的敏感性排序为:阻尼比(λ)>动泊松比(ud)>电阻率(ρ)>阻尼系数(C)>纵波波速(v)>浸润面积(S)>动弹性模量(Ed)>质量(m),由此可在定量检测砂岩的冻融程度时,按参数对冻融作用的敏感性排序选择优先检测的参数种类,以减少检测的工作量;经过定量比较分析,提出了无损测试中各种参数间的关联性,得出了质量、阻尼比、动泊松比、阻尼系数、纵波波速、动弹性模量两两参数之间的定量关系,因此可通过一种参数的变化规律,预测另一种参数的变化趋势,在有限的试验条件、试验次数下,有效地精简所需试验的参数数目。To understand the relationship between the damage mechanism and physical and mechanical parameters of sandstone under the freeze-thaw cycling,,five non-destructive testing methods(resistance test,acoustic test,titration test,CT scan and local microscopic magnification technology)were used to detect rock samples after freeze-thaw cycle test under low-stress cyclic load.According to the test results,the damage and degradation mode of sandstone under the action of freeze-thaw cycle is determined and the flow chart of its degradation mode was drawn.CT scanning was used to obtain the variation law of rock sample CT value,and freeze-thaw degradation and freeze-thaw binding were found.The sensitivity of rock samples'physical and dynamic mechanical parameters to freeze-thaw action is ranked as follows:damping ratio(λ)>dynamic poisson's ratio(ud)>resistivity(ρ)>damping coefficient(C)>longitudinal wave velocity(v)>infiltration area(S)>dynamic mode(Ed)>mass(m);therefore,when the degree of freeze-thaw of sandstone can be quantitatively detected,the parameter types of priority detection can be selected according to the sensitivities of parameters to freeze-thaw action to reduce the workload of detection.Through the quantitative comparison and analysis,the correlations among various parameters in nondestructive testing were proposed,and the quantitative relationships among two parameters of following each other:mass,damping ratio,dynamic poisson's ratio,damping coefficient,longitudinal wave velocity and dynamic mode.Therefore,the variation trend of one parameter can be predicted through the variation law of another parameter,and the number of parameters needed can be effectively reduced when the test conditions and times are limited.

关 键 词：砂岩 冻融循环 冻融损伤 力学特性 无损检测技术 CT扫描 劣化度机理 

分 类 号：TU45.1[建筑科学—岩土工程]