Electrical Response Characteristics of High Temperature Damaged Sandstones Under Uniaxial Compression

doi:10.12068/j.issn.1005-3026.2023.04.014

Abstract

Abstract: In order to study the electrical response characteristics of sandstones after high temperature， uniaxial compression tests were carried out on green sandstone samples at room temperature and heated at 200， 400， 500， 600 and 800℃， and the change law of resistivity during compression was monitored in real time. The results showed that corresponding to the compaction stage， stable crack growth stage， rapid crack growth stage and failure stage of rocks under uniaxial compression， the resistivity change of water-cooled high temperature sandstones shows four stages:small increase， steady increase， significant increase and sharp decrease of resistivity. When the heating temperature is lower than 400℃， the resistivity changing rate in the initial compaction state is under 10%， while when the heating temperature is over 400℃， the changing rate of resistivity increases and can be up to 50% when the heating temperature is 800℃. This indicates that the changing rate of resistivity can reflect the incipient damage degree in rocks. When the compressive pressure reaches 80%~90% of the peak strength， the changing rate of resistivity reaches its peak value， and then decreases sharply， which can be used as a precursor of rock failure. The anisotropic characteristics of resistivity change can indicate the location of the penetrated crack in such a way that the most significant change of resistivity can be observed near the upcoming penetrated crack.

Key words: uniaxial compression; electrical resistivity; high temperature; damage; precursor

CLC Number:

TU45

JIA Peng， LI Bo， ZHU Peng-cheng， WANG Qi-wei. Electrical Response Characteristics of High Temperature Damaged Sandstones Under Uniaxial Compression[J]. Journal of Northeastern University(Natural Science), 2023, 44(4): 558-564.

References

[1]Sun Q，Zhu S Y，Xue L.Electrical resistivity variation in uniaxial rock compression［J］.Arabian Journal of Geosciences，2015，133:565-577.
[2]Lü C，Sun Q.Electrical resistivity evolution and brittle failure of sandstone after exposure to different temperatures［J］.Rock Mechanics & Rock Engineering，2017，51:639-645.
[3]Parkhomenko E I，Bondarenko A T.Geophysics series.Effect of uniaxial pressure on electrical resistivity of rocks［J］.Bulletin of the Academy of Sciences of the USSR，1960(2):326.
[4]Yamazaki Y.Electrical conductivity of strained rocks:laboratory experiments on sedimentary rocks［J］.Bulletin of the Earthquake Research Institute，1965，43:783-802.
[5]Brace W F.Electrical resistivity changes in saturated rock under stress ［J］.Science，1966，153(3743):1525-1526.
[6]Stopinski W.Precursory rock resistivity variations related to mining tremors［J］.Acta Geophys，1982，30 (4):293-320.
[7]Chen G Y，Lin Y M.Stress-strain-electrical resistance effects and associated state equations for uniaxial rock compression［J］.International Journal of Rock Mechanics & Mining Sciences，2004，41:223-236.
[8]李术才，许新骥，刘征宇，等.单轴压缩条件下砂岩破坏全过程电阻率与声发射响应特征及损伤演化［J］.岩石力学与工程学报，2014，33(1):14-23.( Li Shu-cai，Xu Xin-ji，Liu Zheng-yu，et al.Electrical resistivity and acoustic emission response characteristics and damage evolution of sandstone during process of uniaxial compression［J］.Chinese Journal of Rock Mechanics and Engineering，2014，33(1):14-23.)
[9]付艳春，张卫强，刘荡平.岩石破坏与电阻率变化特征研究［J］.煤炭技术，2016，35(4):97-99.(Fu Yan-chun，Zhang Wei-qiang，Liu Dang-ping.Research on rock failure and resistivity variation feature［J］.Coal Technology，2016，35(4):97-99.)
[10]王桦，纪洪广，程桦，等.两淮煤系地层主要岩石单轴受压条件下的导电特性试验研究［J］.岩石力学与工程学报，2010，29(8):1631-1638.(Wang Hua，Ji Hong-guang，Cheng Hua，et al.Experimental study of electrical conductivity of main rocks in strata of Huaibei and Huainan coalfield under uniaxial compression［J］.Chinese Journal of Rock Mechanics and Engineering，2010，29(8):1631-1638.)
[11]Wang Y H，Liu Y F，Ma H T.Changing regularity of rock damage variable and resistivity under loading condition［J］.Safety Science，2012，50(4):718-722.
[12]Zhang W，Sun Q，Hao S Q，et al.Experimental study of the effect of thermal damage on resistivity and mechanical properties of sandstone［J］.Acta Geodynamica et Geomaterialia，2016，13(2):185-192.
[13] Zhang W，Sun Q，Zhu S，et al.The effect of thermal damage on the electrical resistivity of sandstone［J］.Journal of Geophysics and Engineering，2017，14:255-261.
[14]安金珍，修济刚，陈峰，等.单轴压力下有补给水岩石电阻率变化各向异性研究［J］.中国地震，1996(3):300-306.(An Jin-zhen，Xiu Ji-gang，Chen Feng，et al.Anisotropy studies of rock resistivity changes under uniaxial pressure and water replenishment［J］.Earthquake Research in China，1996(3):300-306.)
[15]陈峰，安金珍，廖椿庭.原始电阻率各向异性岩石电阻率变化的方向性［J］.地球物理学报，2003，46(2):271-280.(Chen Feng，An Jin-zhen，Liao Chun-ting，et al.Directional characteristic of resistivity of resistivity changes in rock of original resistivity anisotropy［J］.Chinese Journal of Geophysics，2003，46(2):271-280.)
[16]陈鹏，王恩元，朱亚飞.受载煤体电阻率变化规律的实验研究［J］.煤炭学报，2013，38(4):548-553.(Chen Peng，Wang En-yuan，Zhu Ya-fei.Experimental study on resistivity variation regularities of loading coal［J］.Journal of China Coal Society，2013，38(4):548-553.)
[17]Jia P，Li L，Liu D Q，et al.Insight into rock crack propagation from resistivity and ultrasonic wave variation［J］.Theoretical and Applied Fracture Mechanics，2020，109:102758.
[18]Liu Q，Qian Z，Wu Z.Micro/macro physical and mechanical variation of red sandstone subjected to cyclic heating and cooling:an experimental study［J］.Bulletin of Engineering Geology & the Environment，2017，38(2):15-20.
[19]Yin W，Feng Z，Zhao Y.Effect of grain size on the mechanical behaviour of granite under high temperature and triaxial stresses［J］.Rock Mechanics and Rock Engineering，2021，54(2):1-14.
[20]Olsen A P.Coarse-scale resistivity for saturation estimation in heterogeneous reservoirs based on Archie’s formula［J］.Geophysics，2011，76(2):35-43.