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| Damage mechanism of porous rock caused by moisture migration during freeze-thaw process and experimental verification#br# |
| CHENG Hua1，2，CHEN Hanqing1，CAO Guangyong3，4，RONG Chuanxin2，YAO Zhishu2，CAI Haibing2#br# |
(1. College of Civil and Hydraulic Engineering，Hefei University of Technology，Hefei，Anhui 230001，China；2. College of Civil Engineering and Architecture，Anhui University of Science and Technology，Huainan，Anhui 232001，China；3. College of Civil Engineering and Architecture，Anhui Jianzhu University，Hefei，Anhui 230601，China；4. Anhui Province Key Laboratory of Building Structure and Underground Engineering，Anhui Jianzhu University，Hefei，Anhui 230601，China)
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Abstract In order to study the freeze-thaw damage of porous rock caused by moisture migration inside the pores (cracks) during the freeze-thaw process，the pressure-suction equilibrium state of the film water was analyzed，and it was found that the main role of the liquid pressure is to offset and balance the net suction. The conversion coefficient λ between the pressure variable and the suction variable was given，and it was pointed out that the surface adsorption force comes from the difference between the net suction force and the offset factor λPLy. Based on the capillary theory，the freezing temperature equation of pore water was derived，and the stress state of film water in the frozen large pores was given. Besides，for the “main-side branch” pore structure with poor frost resistance，a capillary-film moisture migration unit model was established，and the stress distribution，migration direction and migration path of the characteristic pores were given. The research results show that the net suction and liquid pressure of the film water inside the frozen main pores are the largest. The net suction force drives the capillary water and film water in the secondary pores and micro-pores to migrate to the main pores，while the increase of the liquid pressure leads to the crack expansion and structural damage of the main pores. Finally，Taking the Jurassic-Cretaceous silty soft rock as the test object，particle analysis，scanning electron microscopy and low field-nuclear magnetic resonance tests were carried out to analyze the mineral composition，pore structure and pore distribution of siltstone，and the correctness of the capillary-film moisture migration unit model was verified according to the change characteristics of T2 spectrum during the freeze-thaw process.
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[1] 刘泉声，黄诗冰，康永水，等. 裂隙岩体冻融损伤研究进展与思考[J]. 岩石力学与工程学报，2015，34(3)：452–471.(LIU Quansheng，HUANG Shibing，KANG Yongshui，et al. Advance and review on freezing-thawing damage of fractured rock[J]. Chinese Journal of Rock Mechanics and Engineering，2015，34(3)：452–471.(in Chinese))
[2] TABER S. The mechanics of frost heaving[J]. The Journal of Geology，1930，38(4)：303–317.
[3] MILLER R D. Frost heaving in non-colloidal soils[C]// The Third International Conference. Edmonton，Canada：[s. n.]，1978：707–713.
[4] KONRAD J M，MORGENSTERN N R. The segregation potential of a freezing soil[J]. Canadian Geotechnical Journal，1981，8(4)，482–491
[5] WALDER J，HALLET B. A theoretical model of the fracture of rock during freezing[J]. Geological Society of America Bulletin，1985，96：336–346.
[6] 刘泉声，黄诗冰，康永水，等. 裂隙冻胀压力及对岩体造成的劣化机制初步研究[J]. 岩土力学，2016，37(6)，1 530–1 542.(LIU Quansheng，HUANG Shibing，KANG Yongshui，et al. Preliminary study on the deterioration mechanism of cracked frost heaving pressure on rock mass[J]. Rock and soil Mechanics，2016，37(6)：1 530–1 542.(in Chinese))
[7] 申艳军，杨更社，王 婷，等. 岩石内孔隙/裂隙冻胀力模型及其适用性评价[J]. 冰川冻土，2019，41(1)：117–128.(SHEN Yanjun，YANG Gengshe，WANG Ting，et al. Evaluation of frost heave force models of pore /fissure in rock and their applicability[J]. Journal of Glaciology and Geocryology，2019，41(1)：117–128.(in Chinese))
[8] 马 巍，王大雁. 冻土力学[M]. 北京：科学出版社，2014：45–46.(MA Wei，WANG Dayan. Mechanics of frozen soil[M]. Beijing：Science Press，2014：45–46.(in Chinese))
[9] EVERETT D H. The thermodynamics of frost damage to porous solids[J]. Physical and Inorganic Chemistry，1961，57：1 541–1 551.
[10] BESKOW G. Soil freezing and frost heaving with special application to roads and railroads[J]. Swedish Geology Survey Yearbook，1935，26(3)：375–380.
[11] LOCH J P G，MILLER R D. Tests of the concept of secondary frost heaving[J]. Soil Science Society of America Journal，1975，39(6)：1 036–1 041.
[12] VAN ALST L J. Laboratory experiments in cold temperature rock deformation[Ph. D. Thesis][D]. Oregon：University of Oregon，2011.
[13] KONRAD J M，MORGENSTERN N R. A mechanistic theory of ice lens formation in fine-grained soils[J]. Canadian Geotechnical Journal，1980，17(4)：473–486
[14] WETTLAUFER J S，WORSTER M G. Dynamic of premelted films：Frost heave in capillary[J]. Physical Review E，1995，51(5)：4 679– 4 589.
[15] 贾海梁，项 伟，谭 龙，等. 砂岩冻融损伤机制的理论分析和实验验证[J]. 岩石力学与工程学报，2016，35(5)：879–895(JIA Hailiang，XIANG Wei，TAN Long，et al. Theoretical analysis and experimental verifications of frost damage mechanism of sandstone[J]. Chinese Journal of Rock Mechanics and Engineering，2016，35(5)：879–895.(in Chinese))
[16] HOPKE S W. A model for frost heave including overburden[J]. Cold Region Science Technology，1980，3(22)：111–127.
[17] GILPIN R R. A model for the prediction of ice lensing and frost heave in soils[J]. Water Resources Research，1980，16(5)：918–930.
[18] O'NEILL K，MILLER R D. Exploration of a rigid ice model of frost heave[J]. Water Resources Research，1985，21(3)：281–296.
[19] NIXON J F. Discrete ice lens theory for frost heave in soils[J]. Canadian Geotechnical Journal，1991，28(6)：843–859.
[20] SHENG D，AXELSSON K，KNUTSSON S. Frost heave due to ice lens formation in freezing soils[J]. Nordic Hydrology，1995，26：125–146.
[21] GILPIN R R. A model of the “liquid-like” layer between ice and a substrate with applications to wire revelation and particle migration[J]. Journal of Colloid and Interface Science，1979，68(3)：235–251.
[22] KAY B D，GEOENEVELT P H. On the interaction of water and heat transport in frozen and unfrozen soils：I. the vapor phase[J]. Soil Science Society of America Journal，1974，38(2)：395–400.
[23] KONRAD J M，MORGENSTERN N R. A mechanistic theory of ice lens formation in fine-grained soils[J]. Canadian Geotechnical Journal，1980，17(4)：473–486.
[24] SCHERER G W. Crystallization in pores[J]. Cement and Concrete Research，1999，29(8)：1 347–1 358
[25] LIU Z，MULDREW K，WAN R G，et al. Measurement of freezing point depression of water in glass capillaries and the associated ice front shape[J]. Physical Review Letters，2003，62(6)：601–602.
[26] WILLIAMS P J，WOOD J A. Internal stresses in frozen ground[J]，Canadian Geotechnical Journal，1985，22：413–416.
[27] LUTZ P，JENISCH R，KLOPFER H，et al. Lehrbuch der Bauphysik[M]. Teubner，Stuttgart：[s. n. ]，1985：353–365.(in German))
[28] 谭 龙，韦昌富，田慧会，等. 冻土未冻水含量的低场核磁共振试验研究[J]. 岩土力学，2015，36(6)：1 566–1 572.(TAN Long，WEI Changfu，TIAN Huihui，et al. Experimental study of unfrozen water content of frozen soils by low-field nuclear magnetic resonance[J]. Rock and Soil Mechanics，2015，36(6)：1 566–1 572.(in Chinese))
[29] YAO Y B，LIU D M ，CHE Y，et al. Petrophysical characterization of coals by low-field nuclear magnetic resonance (NMR)[J]. Fuel，2010，89：1 371–1 380.
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2020, Vol. 39 
