水分与冻融环境下岩石动态拉伸试验及细观分析

PDF(1328 KB)

振动与冲击 ›› 2017, Vol. 36 ›› Issue (20) : 6-11.

论文

闻名1，许金余1,2，王鹏1，刘石1，方新宇1，刘少赫1

作者信息 +

SPLIT TENSILE TESTS AND MESOSTRUCTURE ANALYSES ON RED-SANDSTONE UNDER MOISTURE AND FREEZE-THAW CONDITIONS

WEN Ming1，XU Jinyu1,2，WANG Peng1，LIU Shi1，FANG xinyu1，LIU Shaohe1

Author information +

文章历史 +

摘要

利用直径为100 mm的分离式霍普金森压杆（SHPB）装置与电液伺服压力试验机，进行不同含水率及冻融环境下砂岩试件的动静态劈裂抗拉试验，而后对试件破坏断口进行电镜扫描观察（SEM），立足于细观尺度分析断口形貌特征，并对断口裂隙网络进行量化处理。试验结果表明：饱水、冻融循环处理均会削弱岩样的静动态拉伸强度，其中动态拉伸强度表现出显著的应变率增强效应；基于动态拉伸强度定义软化系数与抗冻系数，该软化系数随应变率的增长近似指数下降，而抗冻系数随应变率的增长近似指数上升；红砂岩破坏断口细观形貌特征主要有3类，分别对应不同的宏观力学性质。以裂隙网络的面积作为损伤变量，探究动态劈拉破坏中的水-应变率效应、冻融-应变率效应对岩石内部损伤扩展的影响，并基于此分析了不同状态下红砂岩的动态劈裂破坏机理，对寒区岩体工程的建设、后期维护具有一定指导意义。

Abstract

By using the hydraulic and servo-controlled pressure testing machine and the split Hopkinson pressure bar (SHPB) with a diameter of 100 mm, the splitting tensile tests of sandstone with different moisture contents and cycles of freeze-thaw were carried out to study the static and dynamic mechanical properties of the sandstone. Then the mesostructure of fracture was analysed base on microscale by pictures obtained through the scanning electron microscope(SEM), tensile failure rules of red sandstone was acquired by the quantitatively processing of fracture network. The results indicate that, the tensile strength of red sandstone decreases with the increase of moisture contents and cycles of freeze-thaw, and the dynamic tensile strength exhibit obvious strain rate hardening effect. The softening coefficient and the coefficient of frost resistance of red sandstone are defined with the dynamic tensile strength, the softening coefficient decreases with the increase of strain rate, while the coefficient of frost resistance increases with the increase of strain rate. Three main fracture microstructure characteristics, corresponding to different macromechanical properties. In the area of the fracture network as damage variable, the rock internal damage extension was analyzed by exploring water-strain rate effect and freeze-thaw-strain rate effect in the dynamic splitting tensile damage, and then analysis of the dynamic fracturing mechanism of red sandstone under different conditions. It is significative for engineering construction and maintenance in cold regions.

导出引用

闻名1，许金余1,2，王鹏1，刘石1，方新宇1，刘少赫1. 水分与冻融环境下岩石动态拉伸试验及细观分析[J]. 振动与冲击, 2017, 36(20): 6-11

WEN Ming1，XU Jinyu1,2，WANG Peng1，LIU Shi1，FANG xinyu1，LIU Shaohe1. SPLIT TENSILE TESTS AND MESOSTRUCTURE ANALYSES ON RED-SANDSTONE UNDER MOISTURE AND FREEZE-THAW CONDITIONS[J]. Journal of Vibration and Shock, 2017, 36(20): 6-11

参考文献

[1] 刘泉声，康永水，黄兴，等. 裂隙岩体冻融损伤关键问题及研究状况[J]. 岩石力学与工程学报，2012，33(4)：971–978.(LIU Quansheng，KANG Yongshui，HUANG Xing，et al. Critical problems of freeze-thaw damage in fractured rock and their research status [J]. Chinese Journal of Rock Mechanics and Engineering，2012，33(4)：971–978.(in Chinese))
[2] 张慧梅，杨更社. 水分及冻融环境下岩石抗拉力学特[J]. 湖南科技大学学报( 自然科学版)，2013，28(3)：35–40.(ZHANG Huimei，YANG Gengshe. Anti-tensile mechanical characteristics of rock under moisture and freeze-thaw condition[J]. Journal of Hunan University of Science＆Technology( Natural Science Edition)，2013，28(3)：35–40. (in Chinese))
[3] Nicholson D T，Nicholson F H. Physical deterioration of sedimentary rocks subjected to experimental freeze-thaw weathering[J]. Earth Surface Processes and Landforms, 2000, 25(12): 1295－1307.
[4] 李杰林，周科平，张亚民，等. 基于核磁共振技术的岩石孔隙结构冻融损伤试验研究[J]. 岩石力学与工程学报，2012，31(6)：1208–1214.(LI Jielin，ZHOU Keping，ZHANG Yamin，et al. Experimental Study Of Rock Porous Structure Damage Characteristics Under Condition Of Freezing-Thawing Cycles Based On Nuclear Magnetic Resonance Technique [J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(6)：1208–1214. (in Chinese))
[5] 尤明庆，陈向雷，苏承东. 干燥及饱水岩石圆盘和圆环的巴西劈裂强度[J]. 岩石力学与工程学报，2011，30(3)：464-472.（YOU Mingqing，CHEN Xianglei，SU Chengdong. Brazilian splitting strengths of discs and rings of rocks in dry and saturated conditions[J]. Chinese Journal of Rock Mechanics and Engineering，2011，30(3)：464-472. (in Chinese))
[6] 朱珍德，张勇，徐卫亚,等. 高围压高水压条件下大理岩断口微观机理分析与试验研究[J]. 岩石力学与工程学报，2005，24(1)：44-51.（ZHU Zhen-de，ZHANG Yong，XU Wei-ya，et al. Experimental studies and microcosmic mechanics analysis on marble rupture under high confining pressure and high hydraulic pressure[J]. Chinese Journal of Rock Mechanics and Engineering，2005，24(1)：44-51. (in Chinese))
[7] 许金余，刘石，孙蕙香. 3 种岩石的平台巴西圆盘动态劈裂拉伸试验分析[J]. 岩石力学与工程学报，2014，33(增1)：2814-2819. (XU Jinyu，LIU Shi，SUN Huixiang. Analysis of dynamic split tensile tests of flattened brazilian disc of three rocks[J]. Chinese Journal of Rock Mechanics and Engineering，2014，33(supp.1)：2814-2819. (in Chinese))
[8] 李夕兵，古德生. 岩石冲击动力学[M]. 长沙：中南工业大学出版社，1994.(LI Xibing，GU Desheng. Rock impact dynamics[M]. Changsha：Central South University of Technology Press，1994.(in Chinese))
[9] 宫凤强，李夕兵，饶秋华，等. 岩SHPB 试验中确定试样尺寸的参考方法[J]. 振动与冲击，2013，32(17)：24-28. (GONG Fengqiang，LI Xibing，RAO Qiuhua，et al. Reference method for determining sample size in SHPB tests of rock materials[J]. JOURNAL OF VIBRATION AND SHOCK，2013，32(17)：24-28. (in Chinese))
[10] Wang Q Z，Xing L. Determination Of Fracture Toughness KIC by using the flattened Brazilian disk specimen of rocks[J]. Eng Fract. Mech. ，1999， 64: 193－201.
[11] 王鹏，许金余，刘石，等. 热损伤砂岩力学与超声时频特性研究[J]. 岩石力学与工程学报，2014，33(9)：1897-1904. (WANG Peng，XU Jinyu，LIU Shi，et al. Mechanical properties and ultrasonic time-frequency characteristics of thermally damaged sandstone [J]. Chinese Journal of Rock Mechanics and Engineering，2014，33(9)：1897-1904. (in Chinese))
[12] 朱珍德，郭海庆. 裂隙岩体水力学基础[M]. 北京：科学出版社，2007. (ZHU Zhende，GUO Haiqing. Fractured rock mass hydraulics basis[M]. Beijing：Science Press，2007. (in Chinese)