基于核磁共振技术的酸性环境下灰岩力学特性劣化试验

为研究灰岩在酸性环境下宏观力学性质的劣化度及细观结构的损伤规律,以重庆某采区的灰岩为研究对象,对经酸性溶液（pH=3,5）和蒸馏水（pH=7）浸泡前后的试件进行核磁共振测量（NMR）,并对浸泡后的试件进行三轴压缩试验,分析了灰岩浸泡前后孔隙度及力学参数的劣化规律。试验结果表明：酸性环境作用下,灰岩内部孔隙呈整体变大的趋势,pH=3时次生大孔隙的生成率较高;在pH=3,5,7条件下,试件孔隙度分别增加12.15%,6.67%,3.43%;随pH值的降低,灰岩的延性特征更明显,峰后应力降进一步减小;除弹性模量的劣化度呈二次减小外,其它力学参数（单轴峰值应力、泊松比、内摩擦角、黏聚力）均呈线性减小的...

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Bibliographic Details
Published in煤炭学报 Vol. 42; no. 7; pp. 1740 - 1747
Main Author 钟祖良 罗玮坤 刘新荣 李皓 陈结 胡翔翔
Format Journal Article
LanguageChinese
Published 2017
Subjects
力学特性
劣化试验
核磁共振
灰岩
酸性环境
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Summary:为研究灰岩在酸性环境下宏观力学性质的劣化度及细观结构的损伤规律,以重庆某采区的灰岩为研究对象,对经酸性溶液（pH=3,5）和蒸馏水（pH=7）浸泡前后的试件进行核磁共振测量（NMR）,并对浸泡后的试件进行三轴压缩试验,分析了灰岩浸泡前后孔隙度及力学参数的劣化规律。试验结果表明：酸性环境作用下,灰岩内部孔隙呈整体变大的趋势,pH=3时次生大孔隙的生成率较高;在pH=3,5,7条件下,试件孔隙度分别增加12.15%,6.67%,3.43%;随pH值的降低,灰岩的延性特征更明显,峰后应力降进一步减小;除弹性模量的劣化度呈二次减小外,其它力学参数（单轴峰值应力、泊松比、内摩擦角、黏聚力）均呈线性减小的规律。此外,酸性环境对灰岩变形参数的影响大于强度参数,而强度参数中,对黏聚力的影响大于内摩擦角。
Bibliography:acidic environment;NMR;mechanical properties;deterioration test;limestone
ZHONG Zu-liang1,2, LUO Wei-kun1,2, LIU Xin-rong1,2, LI Hao1,2, CHEN Jie3, HU Xiang-xiang1,2（ 1. School of Civil Engineering, Chongqing University, Chongqing 400045, China ; 2. Key Laboratory of New Technology for Construction of Cities in Mountain Area ,Ministry of Education, Chongqing University, Chongqing 400045, China; 3. State Key Laboratory of Coal Mine Disaster Dynamics and Controls, Chongqing University, Chongqing 400044, China）
11-2190/TD
In order to discuss the deterioration degree of macroscopic mechanic properties and damage rule of micro structure of limestone under the condition of acidic environment,the limestone of a mine roadway in Chongqing was selected for study.The limestone specimens were immersed in solutions of pH =3,5,7 at the same time and then measured by NMR system to obtain the change rule of porosity.Compared with the dried limestone,the deterioration rule of mechanical properties of pre-immersion specimens were
ISSN:0253-9993