不同化学腐蚀下砂岩冻融力学特性劣化的试验研究

发布时间：2018-03-15 06:06

本文选题：岩石力学　切入点：砂岩　出处：《固体力学学报》2017年06期 　论文类型：期刊论文

【摘要】：通过研究砂岩试样在酸性Na_2SO_4溶液、中性Na_2SO_4溶液和碱性NaOH溶液中浸泡并经历冻融作用后的物理力学特征,分析了砂岩在不同化学溶液中腐蚀30d后及再经历不同冻融循环次数作用后其物理力学特征的变化规律,同时,借助于体视显微镜和SEM扫描电镜对试样微细观结构的损伤劣化进行了观察,并基于孔隙率的变化建立损伤变量来定量的描述试样的损伤劣化程度.试验结果表明:随着冻融循环次数的增加,浸泡在不同化学溶液中砂岩试样的峰值强度及其弹性模量均呈现出指数函数的劣化趋势,而其峰值应变却按指数函数的趋势增加.不同化学溶液下砂岩试样的损伤程度随着冻融循环次数的增加而逐渐加剧,酸性溶液下试样的损伤程度大于中性溶液和碱性溶液下的损伤程度,碱性化学溶液下试样的冻融损伤程度最小.酸性溶液加剧了冻融作用下砂岩试样的损伤劣化程度,而中性至碱性溶液下其冻融损伤程度却得到一定的缓解.化学腐蚀作用与冻融循环作用相互促进、共同影响着砂岩试样的损伤劣化程度.
[Abstract]:The physical and mechanical characteristics of sandstone samples immersed in acidic Na_2SO_4 solution, neutral Na_2SO_4 solution and alkaline NaOH solution were studied. The changes of physical and mechanical characteristics of sandstone after 30 days corrosion in different chemical solutions and after different freezing and thawing cycles are analyzed. The damage deterioration of the microstructures of the samples was observed by means of stereoscopic microscope and SEM scanning electron microscope. Based on the change of porosity, damage variables are established to quantitatively describe the damage deterioration of the sample. The experimental results show that: with the increase of freeze-thaw cycles, The peak strength and elastic modulus of sandstone samples immersed in different chemical solutions show an exponential deterioration trend. But the peak strain increases according to the exponential function. The damage degree of sandstone specimen increases with the increase of freeze-thaw cycle times under different chemical solutions. The damage degree of samples in acid solution is greater than that in neutral solution and alkaline solution, and the damage degree of freezing and thawing in alkaline chemical solution is the least, and the damage deterioration degree of sandstone specimen under freezing and thawing is aggravated by acid solution. However, the degree of freeze-thaw damage in neutral to alkaline solution is alleviated to some extent. Chemical corrosion and freeze-thaw cycle promote each other, which affect the damage deterioration degree of sandstone samples.
【作者单位】：西安理工大学土木建筑工程学院岩土工程研究所;西安理工大学土木建筑工程学院工程力学系;深圳大学广东省滨海耐久性重点实验室;
【基金】：国家自然科学基金项目(51269024,11302167和51769026) 陕西省教育厅重点实验室科研计划项目(16JS074) 宁夏自然科学基金(重点项目)(NZ17002)资助
【分类号】：TU45

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