Experiment study on shear-seepage coupling of clayey soil-structure interface considering contact deformation
-
摘要: 针对高黏土心墙坝岸坡部位接触黏土与混凝土基座接触面的剪切渗流问题,研制了一整套可用于开展黏土与结构接触剪切力学特性和渗流特性研究的剪切–渗流耦合试验系统。该系统可实现接触面的大剪切变形,控制剪切变形与渗流方向正交,自动获取接触面力学特性与渗透特性的演化过程。通过开展接触黏土渗透试验及接触黏土–结构接触面力学特性试验,验证了该试验系统的可靠性。对某高心墙土石坝接触黏土料开展剪切–渗流耦合试验,结果表明:在低正应力下,试样整体渗透系数随剪切变形的增大先减小后增大,最后趋于稳定;在高正应力下,整体渗透系数随剪切变形的增大而不断减小并快速趋于稳定;探讨了不同正应力下土体剪胀性对接触黏土–结构接触面渗透性的影响机制。提出了结构粗糙度对接触面的渗透特性的影响有待进一步研究。Abstract: Aiming at the shear-seepage problem on the interface between the contact clayey soil and the concrete base at the bank slope of a high clay-core dam, a new complete set of shear-seepage test system for clayey soil-structure interface is developed to investigate the mechanical and seepage characteristics of the interface between clayey soil and structure. The test system can produce large shear deformation on the interface, control the orthogonality of the shear deformation and the seepage direction, and automatically obtain the evolution process of mechanical and seepage characteristics of the interface. The compacted clayey soil permeability tests and the mechanical tests on the contact clay-structure interface are carried out to verify the reliability of the test system. The shear-seepage coupling tests are conducted on the contact clayey soil materials of the core wall earth-rock dam. The results indicate that under low normal stress, the permeability coefficient decreases first and then increases with the increase of shear deformation, and finally stabilizes. The permeability coefficient at stability does not exceed the initial permeability coefficient. While under high normal stress, the permeability coefficient decreases continuously and reaches stability with the increase of shear deformation. The influence mechanism of soil dilatancy on the permeability of contact clayey soil-structure interface under different normal stresses is discussed. It is proposed that the influences of structure roughness on the permeability characteristics of the interface need further studies.
-
-
表 1 接触黏土基本物理参数
Table 1 Physical properties of contact clayey soil
液限wL/% 塑限wP/% 塑性指数Ip 土粒相对质量密度Gs 最优含水率wop/% 最大干密度ρdmax/(g·cm-3) 31.0 15.7 15.3 2.725 15.6 1.83 表 2 剪切-渗流试验方案
Table 2 Shear-seepage test schemes
编号 正应力/kPa 剪切位移停顿点/mm 水压力差/kPa #1 100 0, 0.2, 0.4, 0.8, 2, 12, 20 40 #2 200 0, 0.25, 0.5, 1, 2.5, 12, 20 80 #3 400 0, 0.4, 0.8, 1.6, 4, 12, 20 160 #4 800 0, 0.6, 1.2, 2.4, 6, 12, 20 320 #5 1600 0, 0.9, 1.8, 3.6, 9, 12, 20 640 -
[1] 邓刚, 皇甫泽华, 武颖利, 等. 土质心墙土石坝变形协调控制发展与展望[J]. 水力发电学报, 2020, 39(5): 1–16. https://www.cnki.com.cn/Article/CJFDTOTAL-SFXB202005001.htm DENG Gang, HUANGPU Ze-hua, WU Ying-li, et al. Development and prospect of deformation compatibility control of earth core embankment dams[J]. Journal of Hydroelectric Engineering, 2020, 39(5): 1–16. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-SFXB202005001.htm
[2] 解全一. 平原水库均质土坝与穿坝涵管接触冲刷破坏机理及监测技术研究[D]. 济南: 山东大学, 2019. XIE Quan-yi. Study on the Failure Mechanism and Monitoring Technology of Culvert-Dam Interfacial Erosion in Homogenous Earth-Fill Dams of Plain Reservoirs[D]. Jinan: Shandong University, 2019. (in Chinese)
[3] 吴智敏. 土石坝与输水涵管在稳定渗流期的接触冲刷及坝体稳定性分析[D]. 济南: 山东大学, 2016. WU Zhi-min. Contact Scouring and Stability Analysis for Earth Rock-Fill Dam and Concrete Culvert During Stable Seepage Period[D]. Jinan: Shandong University, 2016. (in Chinese)
[4] 吴梦喜, 余学明, 叶发明. 高心墙堆石坝坝基防渗墙与心墙连接方案研究[J]. 长江科学院院报, 2010, 27(9): 59–64. https://www.cnki.com.cn/Article/CJFDTOTAL-CJKB201009015.htm WU Meng-xi, YU Xue-ming, YE Fa-ming. Research on conjoining scheme for anti-seepage wall of high rockfill dam with earth core[J]. Journal of Yangtze River Scientific Research Institute, 2010, 27(9): 59–64. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-CJKB201009015.htm
[5] 郝巨涛, 刘增宏, 瞿扬. 沥青混凝土防渗面板与黏土铺盖之间接触渗透性能的试验研究[J]. 岩土工程学报, 2007, 29(12): 1800–1803. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC200712009.htm HAO Ju-tao, LIU Zeng-hong, QU Yang. Tests on interfacial seepage between asphalt concrete facing and soil blanket[J]. Chinese Journal of Geotechnical Engineering, 2007, 29(12): 1800–1803. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC200712009.htm
[6] 汪小刚. 高土石坝几个问题探讨[J]. 岩土工程学报, 2018, 40(2): 203–222. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201802002.htm WANG Xiao-gang. Discussion on some problems observed in high earth-rockfill dams[J]. Chinese Journal of Geotechnical Engineering, 2018, 40(2): 203–222. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201802002.htm
[7] CHEN X B, ZHANG J S, XIAO Y J, et al. Effect of roughness on shear behavior of red clay–concrete interface in large-scale direct shear tests[J]. Canadian Geotechnical Journal, 2015, 52(8): 1122–1135. doi: 10.1139/cgj-2014-0399
[8] HU L M, PU J L. Testing and modeling of soil-structure interface[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2004, 130(8): 851–860. doi: 10.1061/(ASCE)1090-0241(2004)130:8(851)
[9] WANG X, CHENG H, YAN P, et al. The influence of roughness on cyclic and post-cyclic shear behavior of red clay-concrete interface subjected to up to 1000 cycles[J]. Construction and Building Materials, 2021, 273: 121718. doi: 10.1016/j.conbuildmat.2020.121718
[10] CHAPUIS R P. Predicting the saturated hydraulic conductivity of soils: a review[J]. Bulletin of Engineering Geology and the Environment, 2012, 71(3): 401–434. doi: 10.1007/s10064-012-0418-7
[11] XIE Q Y, LIU J, HAN B, et al. Experimental and numerical investigation of bottom outlet leakage in earth-fill dams[J]. Journal of Performance of Constructed Facilities, 2019, 33(3): 04019037. doi: 10.1061/(ASCE)CF.1943-5509.0001302
[12] XIE Q Y, LIU J, HAN B, et al. Experimental investigation of interfacial erosion on culvert-soil interface in earth dams[J]. Soils and Foundations, 2019, 59(3): 671–686. doi: 10.1016/j.sandf.2019.02.004
[13] XIE Q Y, LIU J, HAN B, et al. Critical hydraulic gradient of internal erosion at the soil–structure interface[J]. Processes, 2018, 6(7): 92. doi: 10.3390/pr6070092
[14] KIMURA S, KANEKO H, NODA S, et al. Shear-induced permeability reduction and shear-zone development of sand under high vertical stress[J]. Engineering Geology, 2018, 238: 86–98. doi: 10.1016/j.enggeo.2018.02.018
[15] 魏星, 邹婷, 王刚. 压–剪耦合条件下黏土渗透特性的试验研究[J]. 岩石力学与工程学报, 2017, 36(增刊1): 3561–3568. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2017S1050.htm WEI Xing, ZOU Ting, WANG Gang. Experimental study on permeability of clay during coupled compression and shear[J]. Chinese Journal of Rock Mechanics and Engineering, 2017, 36(S1): 3561–3568. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2017S1050.htm
[16] 王刚, 游克勤, 魏星, 等. 压实黏土剪切带渗透特性试验研究[J]. 岩土工程学报, 2019, 41(8): 1530–1537. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201908021.htm WANG Gang, YOU Ke-qin, WEI Xing, et al. Experimental study on permeability of shear bands in compacted clay[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(8): 1530–1537. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201908021.htm
[17] LUO Y L, LUO B, XIAO M. Effect of deviator stress on the initiation of suffusion[J]. Acta Geotechnica, 2020, 15(6): 1607–1617. doi: 10.1007/s11440-019-00859-x
[18] CHANG D S, ZHANG L M. Critical hydraulic gradients of internal erosion under complex stress states[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2013, 139(9): 1454–1467. doi: 10.1061/(ASCE)GT.1943-5606.0000871
[19] CHEN C, ZHANG L M, CHANG D S. Stress-strain behavior of granular soils subjected to internal erosion[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2016, 142(12): 06016014. doi: 10.1061/(ASCE)GT.1943-5606.0001561
[20] 雷红军, 卞锋, 于玉贞, 等. 黏土大剪切变形中的渗透特性试验研究[J]. 岩土力学, 2010, 31(4): 1130–1133. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201004025.htm LEI Hong-jun, BIAN Feng, YU Yu-zhen, et al. Experimental study of permeability of clayey soil during process of large shear deformation[J]. Rock and Soil Mechanics, 2010, 31(4): 1130–1133. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201004025.htm
[21] 王刚, 韦林邑, 魏星, 等. 压实黏土三轴压缩变形过程中的渗透性变化规律[J]. 岩土力学, 2020, 41(1): 32–38. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX202001005.htm WANG Gang, WEI Lin-yi, WEI Xing, et al. Permeability evolution of compacted clay during triaxial compression[J]. Rock and Soil Mechanics, 2020, 41(1): 32–38. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX202001005.htm
[22] 雷红军. 高土石坝黏性土大剪切变形条件下渗透特性研究[D]. 北京: 清华大学, 2010. LEI Hong-jun. A Study on Seepage Characteristics of Clayey Soil of High Earth-Rockfill Dam with Large Shear Deformation[D]. Beijing: Tsinghua University, 2010. (in Chinese)
[23] 雷红军, 刘中阁, 于玉贞, 等. 黏土-结构接触面大剪切变形后渗流特性试验研究[J]. 岩土力学, 2011, 32(4): 1040–1044. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201104013.htm LEI Hong-jun, LIU Zhong-ge, YU Yu-zhen, et al. Experimental study of seepage characteristics of clayey soil-structure interface under large shear deformation[J]. Rock and Soil Mechanics, 2011, 32(4): 1040–1044. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201104013.htm
[24] 刘千惠, 王翔南, 湛正刚, 等. 黏性土-结构接触面剪切变形时的渗透机理分析[J]. 水力发电学报, 2021, 40(9): 113–121. https://www.cnki.com.cn/Article/CJFDTOTAL-SFXB202109012.htm LIU Qian-hui, WANG Xiang-nan, ZHAN Zheng-gang, et al. Analysis of seepage mechanism on clayey soil-structure interface under shear[J]. Journal of Hydroelectric Engineering, 2021, 40(9): 113–121. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-SFXB202109012.htm
[25] LUO Y L, JIN X, LI X, et al. A new apparatus for evaluation of contact erosion at the soil–structure interface[J]. Geotechnical Testing Journal, 2013, 36(2): 20120094. doi: 10.1520/GTJ20120094
[26] LUO Y L, ZHAN M L, SHENG J C, et al. Hydro-mechanical coupling mechanism on joint of clay core-wall and concrete cut-off wall[J]. Journal of Central South University, 2013, 20(9): 2578–2585. doi: 10.1007/s11771-013-1771-9
[27] WANG S, CHEN J S, SHENG J C, et al. Laboratory investigation of stress state and grain composition affecting internal erosion in soils containing a suspended cut-off wall[J]. KSCE Journal of Civil Engineering, 2016, 20(4): 1283–1293. doi: 10.1007/s12205-015-0719-z
[28] WANG S, CHEN J S, LUO Y L, et al. Experiments on internal erosion in sandy gravel foundations containing a suspended cutoff wall under complex stress states[J]. Natural Hazards, 2014, 74(2): 1163–1178. doi: 10.1007/s11069-014-1243-z
[29] 邓刚, 张茵琪, 张延亿, 等. 压实宽级配黏土与刚性面结合带抗渗特性研究[J]. 岩土工程学报, 2021, 43(9): 1–9. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC202109011.htm DENG Gang, ZHANG Yin-qi, ZHANG Yan-yi, et al. Study on impermeability characteristics of junctional zone between compacted broadly graded clayey soil and hard surface[J]. Chinese Journal of Geotechnical Engineering, 2021, 43(9): 1–9. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC202109011.htm
[30] 张茵琪, 邓刚, 张延亿, 等. 宽级配黏土与混凝土结合带渗透特性试验研究[J]. 水利水电技术, 2021: 1–8. ZHANG Yin-qi, DENG Gang, ZHANG Yan-yi, et al. Experimental study on permeability characteristics of junctional zone between widely graded clay and concrete[J]. Water Resources and Hydropower Engineering, 2021: 1–8. (in Chinese)
[31] 张乐, 党发宁, 高俊, 等. 线性加载条件下考虑应力历史的饱和黏土一维非线性固结渗透试验研究[J]. 岩土力学, 2021, 42(4): 1078–1087. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX202104020.htm ZHANG Le, DANG Fa-ning, GAO Jun, et al. One dimensional nonlinear consolidation permeability test of saturated clay considering stress history under a ramp loading[J]. Rock and Soil Mechanics, 2021, 42(4): 1078–1087. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX202104020.htm