Shear strength of dam abutment fractured rock weakens critical water pressure and statistical damage constitutive model

XIE Hui; CHEN Ying; XIANG Yong; WANG Haoran; MA Fangping

doi:10.16511/j.cnki.qhdxxb.2023.26.019

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Journal of Tsinghua University(Science and Technology) ›› 2023, Vol. 63 ›› Issue (7) : 1113-1123. DOI: 10.16511/j.cnki.qhdxxb.2023.26.019

Research Article

Shear strength of dam abutment fractured rock weakens critical water pressure and statistical damage constitutive model

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Abstract

[Objective] The weakening of abutment rock strength under water-rock coupling has an important impact on the long-term safe and stable operation of high-arch dams. Under the joint action of prolonged arch thrust and high water pressure, the strength parameters of the rock in the weak interlayer of the dam abutment are reduced, which readily causes long-term stability problems such as structural instability, seepage damage, and bank slope sliding of the high dam hub. [Methods] Given the water pressure weakening effect of the shear strength parameters of the fractured marble at the dam abutment, the triaxial compression test of the fractured rock under the action of different seepage water pressures was performed using the rock mechanics testing system, and then the influence of seepage water pressure on the compressive strength, cohesion, and friction coefficient of the fractured rock was analyzed in combination with the rock stress-strain curve. Finally, the weakening critical water pressure of the rock was obtained by analyzing the effective stress principle. Furthermore, the statistical damage constitutive model of rock considering seepage pressure was studied. [Results] The results showed that the influence of seepage water pressure on the shear strength parameters of the fractured marble was mainly manifested by a weakening effect on cohesion. The weakening rate of cohesion increased substantially with increasing seepage water pressure, and the maximum weakening rate was nearly 100%. The weakened cohesion decreased linearly with increasing water pressure; when the weakening rate of cohesion was 0, the water pressure was the weakening critical water pressure. When the water pressure was lower than the critical water pressure, the water pressure weakening effect of rock strength was obvious, and the cohesion decreased linearly with increasing water pressure until vanishing; when the water pressure exceeded the critical water pressure, the rock strength decreased insubstantially with increasing water pressure, and the water pressure weakening effect of rock strength was not obvious. Based on the influence of seepage water pressure on shear strength parameters, a statistical damage constitutive model of rock considering the weakening effect of water pressure was constructed, and the adaptability and rationality of the theoretical model were verified using test data. [Conclusions] The critical water pressure, as the limiting value of the weakening of the rock strength and cohesion by the seepage pressure, can be used to define the influence of the seepage pressure on the rock strength. The statistical damage constitutive model considering the weakening effect of the seepage pressure can calculate the evolution law of the entire process of rock fracture under the water-rock coupling effect. The research results provide strong support for the theory and testing of water pressure weakening and have certain reference values and scientific significance for studying the weakening effect of fractured rock and analyzing the stability of high-arch dam abutments.

Key words

fissured rock / shear strength parameters / weakening effect / critical water pressure / constitutive model

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XIE Hui, CHEN Ying, XIANG Yong, WANG Haoran, MA Fangping. Shear strength of dam abutment fractured rock weakens critical water pressure and statistical damage constitutive model[J]. Journal of Tsinghua University(Science and Technology). 2023, 63(7): 1113-1123 https://doi.org/10.16511/j.cnki.qhdxxb.2023.26.019

References

[1] 张秀丽.国内外大坝失事或水电站事故典型案例原因汇集[J].大坝与安全, 2015(1):13-16. ZHANG X L. Collection of typical cases of dam failures and accidents at hydropower stations[J]. Dam and Safety, 2015(1):13-16.(in Chinese)
[2] HADIZADEH J, LAW R D. Water-weakening of sandstone and quartzite deformed at various stress and strain rates[J]. International Journal of Rock Mechanics and Mining Sciences&Geomechanics Abstracts, 1991, 28(5):431-439.
[3] HEGGHEIM T, MADLAND M V, RISNES R, et al. A chemical induced enhanced weakening of chalk by seawater[J]. Journal of Petroleum Science and Engineering, 2005, 46(3):171-184.
[4] RISNES R, HAGHIGHI H, KORSNES R I, et al. Chalk-fluid interactions with glycol and brines[J]. Tectonophysics, 2003, 370(1-4):213-226.
[5] 王思敬,马凤山,杜永廉.水库地区的水岩作用及其地质环境影响[J].工程地质学报, 1996, 4(3):1-9. WANG S J, MA F S, DU Y L. On the rock-water interaction in reservoir areas and its geoenvironmental effect[J]. Journal of Engineering Geology, 1996, 4(3):1-9.(in Chinese)
[6] JENG F S, LIN M L, HUANG T H. Wetting deterioration of soft sandstone-microscopic insights[C]//Proceedings of the ISRM International Symposium. Melbourne, Australia:ISRM, 2000:ISRM-IS-2000-198.
[7] LIN M L, JENG F S, TSAI L S, et al. Wetting weakening of tertiary sandstones-microscopic mechanism[J]. Environmental Geology, 2005, 48(2):265-275.
[8] DENG H F, YUAN X F, WANG L H, et al. Experimental research on changes in the mechanical property law of reservoir bank sandstone under "immersion-air dry" circulation[J]. Environmental Engineering and Management Journal, 2013, 12(9):1785-1789.
[9] DENG H F, ZHOU M L, LI J L, et al. Creep degradation mechanism by water-rock interaction in the red-layer soft rock[J]. Arabian Journal of Geosciences, 2016, 9(12):601.
[10] 邓华锋,支永艳,段玲玲,等.水-岩作用下砂岩力学特性及微细观结构损伤演化[J].岩土力学, 2019, 40(9):3447-3456. DENG H F, ZHI Y Y, DUAN L L, et al. Mechanical properties of sandstone and damage evolution of microstructure under water-rock interaction[J]. Rock and Soil Mechanics, 2019, 40(9):3447-3456.(in Chinese)
[11] 汤连生,张鹏程,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. TANG L S, ZHANG P C, WANG S J. Testing study on macroscopic mechanics effect of chemical action of water on rocks[J]. Chinese Journal of Rock Mechanics and Engineering, 2002, 21(4):526-531.(in Chinese)
[12] 刘新荣,傅晏,王永新,等.(库)水-岩作用下砂岩抗剪强度劣化规律的试验研究[J].岩土工程学报, 2008, 30(9):1298-1302. LIU X R, FU Y, WANG Y X, et al. Deterioration rules of shear strength of sand rock under water-rock interaction of reservoir[J]. Chinese Journal of Geotechnical Engineering, 2008, 30(9):1298-1302.(in Chinese)
[13] 任浩楠,徐进,刘建锋,等.破裂面水压对砂板岩峰后强度影响的试验研究[J].岩土力学, 2013, 34(4):1053-1057. REN H N, XU J, LIU J F, et al. Experimental research on influence of pore pressure at fracture surface on post-peak strength of sandy slate[J]. Rock and Soil Mechanics, 2013, 34(4):1053-1057.(in Chinese)
[14] 李佳伟,徐进,王璐,等.砂板岩岩体力学特性的水岩耦合试验研究[J].岩土工程学报, 2013, 35(3):599-604. LI J W, XU J, WANG L, et al. Water-rock coupling tests on mechanical properties of sandy slate rock mass[J]. Chinese Journal of Geotechnical Engineering, 2013, 35(3):599-604.(in Chinese)
[15] 杨宝全,张林,徐进,等.高拱坝坝肩软岩及结构面强度参数水岩耦合弱化效应试验研究[J].四川大学学报(工程科学版), 2015, 47(2):21-27, 35. YANG B Q, ZHANG L, XU J, et al. Experimental study of weakening effect of water-rock coupling interaction on strength parameters of dam abutment weak rock and structural plane for high arch dam[J]. Journal of Sichuan University (Engineering Science Edition), 2015, 47(2):21-27, 35.(in Chinese)
[16] 刘再斌.孔隙水压作用下岩石抗剪强度参数计算[J].中国煤炭地质, 2013, 25(4):30-33. LIU Z B. Computation of rock shear strength relevant parameters under pore-space water pressure[J]. Coal Geology of China, 2013, 25(4):30-33.(in Chinese)
[17] 傅晏,刘新荣,张永兴,等.水岩相互作用对砂岩单轴强度的影响研究[J].水文地质工程地质, 2009, 36(6):54-58. FU Y, LIU X R, ZHANG Y X, et al. Study on the influence of water-rock interaction to the strength of sandstone[J]. Hydrogeology&Engineering Geology, 2009, 36(6):54-58.(in Chinese)
[18] 邓华锋,肖志勇,李建林,等.水岩作用下损伤砂岩强度劣化规律试验研究[J].岩石力学与工程学报, 2015, 34(S1):2690-2698. DENG H F, XIAO Z Y, LI J L, et al. Deteriorating change rule test research of damage sandstone strength under water-rock interaction[J]. Chinese Journal of Rock Mechanics and Engineering, 2015, 34(S1):2690-2698.(in Chinese)
[19] 汤连生,张鹏程,王洋.水作用下岩体断裂强度探讨[J].岩石力学与工程学报, 2004, 23(19):3337-3341. TANG L S, ZHANG P C, WANG Y. On fracture strength of rocks with cracks under water action[J]. Chinese Journal of Rock Mechanics and Engineering, 2004, 23(19):3337-3341.(in Chinese)
[20] 李庆斌,陈樟福生,孙满义,等.真实水荷载对混凝土强度影响的试验研究[J].水利学报, 2007, 38(7):786-791. LI Q B, CHEN Z F S, SUN M Y, et al. Effect of water loading on strength of concrete[J]. Journal of Hydraulic Engineering, 2007, 38(7):786-791.(in Chinese)
[21] 陈英,马东涛,何德伟.真实水压力下砂岩强度及破坏形式试验研究[J].四川大学学报(工程科学版), 2015, 47(S1):59-64. CHEN Y, MA D T, HE D W. Tests for sandstone strength and failure model under water loading[J]. Journal of Sichuan University (Engineering Science Edition), 2015, 47(S1):59-64.(in Chinese)
[22] 陈英.水岩耦合作用下坝肩岩石蠕变规律及拱坝长期稳定研究[D].成都:四川大学, 2021. CHEN Y. Research on long-term stability of arch dam and creep properties of abutment rock under water-rock coupling[D]. Chengdu:Sichuan University, 2021.(in Chinese)
[23] CAO W G, LI X, ZHAO H. Damage constitutive model for strain-softening rock based on normal distribution and its parameter determination[J]. Journal of Central South University of Technology, 2007, 14(5):719-724.
[24] 刘齐建,杨林德,曹文贵.岩石统计损伤本构模型及其参数反演[J].岩石力学与工程学报, 2005, 24(4):616-621. LIU Q J, YANG L D, CAO W G. Statistical damage constitutive model for rock and back analysis of its parameters[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(4):616-621.(in Chinese)
[25] 陈忠辉,傅宇方,唐春安.岩石破裂声发射过程的围压效应[J].岩石力学与工程学报, 1997, 16(1):65-70. CHEN Z H, FU Y F, TANG C A. Confining pressure effect on acoustic emissions during rock failure[J]. Chinese Journal of Rock Mechanics and Engineering, 1997, 16(1):65-70.(in Chinese)
[26] 杨明辉,赵明华,曹文贵.岩石损伤软化统计本构模型参数的确定方法[J].水利学报, 2005, 36(3):345-349. YANG M H, ZHAO M H, CAO W G. Method for determining the parameters of statistical damage softening constitutive model for rock[J]. Journal of Hydraulic Engineering, 2005, 36(3):345-349.(in Chinese)