冻融循环作用对砂岩强度特性影响的试验研究
|
摘要
为研究冻融循环作用下砂岩强度特性变化规律,开展了天然砂岩在不同冻融循环次数作用下的室内试验,分析砂岩的破坏特性、抗剪强度参数及弹性模量变化规律,结果表明:砂岩经过冻融循环作用后,其破坏面形式与天然状态下的砂岩破坏面形式保持相同;其内摩擦角随着冻融循环次数的增加呈现先增大后保持不变的变化规律;而黏聚力呈现先减小后保持不变的变化规律;对于砂岩试样的弹性模量,随着冻融循环次数的增加呈现减小的趋势;且当循环次数较少时,其弹性模量减小幅度较大;当冻融循环次数达到一定后,其弹性模量减小幅度较小。
To investigate the variation pattern of sandstone strength characteristics under the influence of freeze-thaw cycles, indoor experiments of natural sandstone were carried out under different freeze-thaw cycle indexes. The failure characteristics, shear strength parameters and elastic modulus varying pattern of sandstone were analyzed, and the results were shown below. After the freeze-thaw cycle, the failure surface of sandstones remained the same with natural sandstone failure surface. The internal friction angle increased at first and then remained constant as the number of freeze-thaw cycles increased, while the cohesion had a decreasing tendency and then remains unchanged. For the elastic modulus of the sandstone samples, it decreased with the increase of the number of freeze-thaw cycle. However, when the number of cycles was low, the elastic modulus decreased greatly. As the cycle number reached a certain level, the elastic modulus decreased less.
To investigate the variation pattern of sandstone strength characteristics under the influence of freeze-thaw cycles, indoor experiments of natural sandstone were carried out under different freeze-thaw cycle indexes. The failure characteristics, shear strength parameters and elastic modulus varying pattern of sandstone were analyzed, and the results were shown below. After the freeze-thaw cycle, the failure surface of sandstones remained the same with natural sandstone failure surface. The internal friction angle increased at first and then remained constant as the number of freeze-thaw cycles increased, while the cohesion had a decreasing tendency and then remains unchanged. For the elastic modulus of the sandstone samples, it decreased with the increase of the number of freeze-thaw cycle. However, when the number of cycles was low, the elastic modulus decreased greatly. As the cycle number reached a certain level, the elastic modulus decreased less.
引文
[1] 李鹏, 刘建, 李国和,等. 水化学作用对砂岩抗剪强度特性影响效应研究[J]. 岩土力学, 2011, 32(2):380-386.
[2] 汤连生, 张鹏程. 水化学损伤对岩石弹性模量的影响[J]. 中山大学学报(自然科学版), 2000, 29(5):126-128.
[3] 汤连生, 王思敬. 水—岩化学作用的岩石宏观力学效应的试验研究[J]. 岩石力学与工程学报, 2002, 21(4):526-531.
[4] YANG G S, ZHANG Q S, PU Y B. A Study on the damage propagation characteristics of rock under the frost and thaw condition[J]. Chinese Journal of Geotechnical Engineering, 2004, 26(6): 838-842.
[5] 袁智洪, 简富献, 黄诗渊,等. 掺砂高塑性红黏土抗剪强度直剪试验研究[J]. 人民珠江, 2017, 38(5):32-35.
[6] 杨更社, 奚家米, 李慧军,等. 三向受力条件下冻结岩石力学特性试验研究[J]. 岩石力学与工程学报, 2010, 29(3):459-464.
[7] 俞缙, 傅国锋, 陈旭,等. 冻融循环后砂岩三轴卸围压力学特性试验研究[J]. 岩石力学与工程学报, 2015(10):2001-2009.
[8] 韩铁林, 师俊平, 陈蕴生. 砂岩在化学腐蚀和冻融循环共同作用下力学特征劣化的试验研究[J]. 水利学报, 2016, 47(5):644-655.
[9] 张慧梅, 杨更社. 冻融与荷载耦合作用下岩石损伤模型的研究[J]. 岩石力学与工程学报, 2010, 29(3):471-476.
[10] NICHOLSON H, DAWNT P, NICHOLSON F. Physical deterioration of sedimentary rocks subjected to experimental freezing-thawing weathering [J].Earth Surface Processes and Lancfforms, 2000, 25(12) : 1295-1308.
[2] 汤连生, 张鹏程. 水化学损伤对岩石弹性模量的影响[J]. 中山大学学报(自然科学版), 2000, 29(5):126-128.
[3] 汤连生, 王思敬. 水—岩化学作用的岩石宏观力学效应的试验研究[J]. 岩石力学与工程学报, 2002, 21(4):526-531.
[4] YANG G S, ZHANG Q S, PU Y B. A Study on the damage propagation characteristics of rock under the frost and thaw condition[J]. Chinese Journal of Geotechnical Engineering, 2004, 26(6): 838-842.
[5] 袁智洪, 简富献, 黄诗渊,等. 掺砂高塑性红黏土抗剪强度直剪试验研究[J]. 人民珠江, 2017, 38(5):32-35.
[6] 杨更社, 奚家米, 李慧军,等. 三向受力条件下冻结岩石力学特性试验研究[J]. 岩石力学与工程学报, 2010, 29(3):459-464.
[7] 俞缙, 傅国锋, 陈旭,等. 冻融循环后砂岩三轴卸围压力学特性试验研究[J]. 岩石力学与工程学报, 2015(10):2001-2009.
[8] 韩铁林, 师俊平, 陈蕴生. 砂岩在化学腐蚀和冻融循环共同作用下力学特征劣化的试验研究[J]. 水利学报, 2016, 47(5):644-655.
[9] 张慧梅, 杨更社. 冻融与荷载耦合作用下岩石损伤模型的研究[J]. 岩石力学与工程学报, 2010, 29(3):471-476.
[10] NICHOLSON H, DAWNT P, NICHOLSON F. Physical deterioration of sedimentary rocks subjected to experimental freezing-thawing weathering [J].Earth Surface Processes and Lancfforms, 2000, 25(12) : 1295-1308.