渗透作用下滑带细观结构演变特性

安鹏举; 鲁莎; 唐辉明; 孙思璇; 张子涵; 缪明昊

doi:10.19509/j.cnki.dzkq.2022.0226

渗透作用下滑带细观结构演变特性

doi: 10.19509/j.cnki.dzkq.2022.0226

中国地质大学(武汉)工程学院, 武汉 430074

基金项目:

国家自然科学基金重大项目 42090054

国家自然科学基金项目 42107194

详细信息

作者简介:
安鹏举(1990-), 男, 助理研究员, 主要从事滑坡地质灾害分析与防治方面的研究工作。E-mail: 308981376@qq.com

通讯作者:
唐辉明(1962-), 男, 教授, 博士生导师, 主要从事工程地质与岩土工程的教学和科研工作。E-mail: tanghm@cug.edu.cn

中图分类号: TU413.6⁺2
计量
- 文章访问数: 732
- PDF下载量: 58
- 被引次数: 0
出版历程
- 收稿日期: 2022-07-21

Meso-structure evolution of the sliding zone under seepage conditions

Faculty of Engineering, China University of Geosciences(Wuhan), Wuhan 430074, China

摘要

摘要:
库岸滑坡受到库水升降作用影响, 内部渗透压力会产生周期性的变化。动态渗透压力会导致滑带结构与强度产生劣化, 进而影响滑坡整体稳定性。为揭示滑带在渗透作用下的结构演变特征, 通过室内渗流试验结合CT扫描技术获取了黄土坡滑坡滑带在不同渗流条件下的细观结构特征, 采用Avizo软件量化滑带细观结构参数, 定量分析了不同渗透条件下滑带结构的演变规律。结果表明, 滑带的渗透系数随渗流时长的增加而呈指数形式下降, 且水力梯度越大最终试样的渗透系数越小; 连续的CT重构图像显示渗流过程中部分黏土团聚体发生解体, 大孔隙被附近的细颗粒逐渐充填, 试样结构的宏观均一性增强; 统计数据表明滑带土的表观孔隙率由5%下降到了1%, 等效直径小于80 μm的孔隙占比随渗流时长的增加而增多, 而等效直径大于80 μm的孔隙占比随渗流时长的增加而减少。结果证明周期性渗透作用会影响滑带内孔隙结构的分布特征, 细观上表现为大孔隙被小颗粒充填, 导致渗流通道变得细长而弯曲, 孔隙的有效连通性被削弱, 宏观上表现为渗透系数随渗流时长的增加而降低。
- 渗透作用 /
- 滑带 /
- 细观结构 /
- 孔隙 /
- 黄土坡滑坡
Abstract:
Periodic fluctuations of reservoir water level lead to the variations in seepage stress inside landslide bodies. Dynamic seepage pressures can lead to deterioration in the structure and strength of the slide zone, which affects the stability of the landslide. To identify the effect of seepage on the pore structure of the slip zone, the seepage tests were performed. First, a seepage test apparatus was developed and combined with CT scanning technology to obtain the meso-structure of the sliding zone under different seepage conditions. Then, the changes in the structural parameters of the slip zone soils were quantified by Avizo software. Finally, the mechanism of the meso-structural evolution of the sliding zone under seepage was analyzed. The results show that the permeability coefficient of the sliding zone decreases exponentially with time, and a higher seepage pressure will lead to a smaller permeability coefficient of the sliding zone. Statistical data show that the apparent porosity of sliding zone soil decreases from 5% to 1%. The proportion of pores with an equivalent spherical diameter of less than 80 μm increases with seepage time, while the proportion of pores with an equivalent spherical diameter greater than 80 μm decreases with seepage time. The above results indicate that the large pores in the slip zone soils are filled with small particles during the seepage.Hence, the seepage channels become elongated and curved, and the effective connectivity of the pores is weakened.
- seepage /
- sliding zone /
- meso-structure /
- pore /
- Huangtupo landslide

HTML全文

图 1 黄土坡滑坡工程地质平面图

Figure 1. Engineering geology map of the Huangtupo landslide

下载: 全尺寸图片幻灯片

图 2 黄土坡临江1号滑坡

1.崩滑堆积体；2.松散堆积物；3.巴东组灰岩；4.巴东组泥质灰岩；5.碎裂岩；6.软弱夹层；7.深层滑动面；8.松散堆积物与崩滑堆积体界线；9.浅层滑动面; 10.水位线。G2，G7，G9，G11.坡表位移监测点；HZK5, HZK7, HZK8.深部位移监测孔

Figure 2. Linjiang No.1 landslide of the Huangtupo landslide

下载: 全尺寸图片幻灯片

图 3 黄土坡临江1号滑坡滑带土颗粒级配

Figure 3. Particle-size distribution of sliding zone soil in the Linjiang No.1 landslide of the Huangtupo landslide

下载: 全尺寸图片幻灯片

图 4 动态渗透压控制系统

Figure 4. Dynamic seepage control system

下载: 全尺寸图片幻灯片

图 5 高分辨率CT扫描仪

Figure 5. High resolution CT scanner

下载: 全尺寸图片幻灯片

图 6 渗透系数随渗流次数的变化图

Figure 6. Variation in the permeability coefficient with seepage time

下载: 全尺寸图片幻灯片

图 7 滑带试样CT扫描结果

Figure 7. CT scan results of the sliding zone soil

下载: 全尺寸图片幻灯片

图 8 长期浸泡作用下滑带CT切片图

Figure 8. CT image slices of the sliding zone under long-term immersion

下载: 全尺寸图片幻灯片

图 9 渗透作用下试样表观孔隙变化图

Figure 9. Changes in the apparent porosity of the specimens under seepage

下载: 全尺寸图片幻灯片

图 10 试样孔隙率随渗透循环次数的变化

a, c, e分别为试样S2、S3和S4在连续切片上的孔隙率变化；b, d, f分别为S2、S3和S4的平均孔隙率随渗透循环次数的变化趋势

Figure 10. Porosity of the specimens changes with the number of seepage cycles

下载: 全尺寸图片幻灯片

图 11 不同等效直径孔隙频率占比随渗透循环次数的变化结果(S2-0代表试样S2经过0次渗透循环，其他以此类推)

Figure 11. Changes in pore distribution with the number of seepage cycles

下载: 全尺寸图片幻灯片

图 12 渗透作用下滑带细观结构变化示意图

Figure 12. Schematic diagram of the meso-structural changes in the sliding zone soil under seepage

下载: 全尺寸图片幻灯片

表 1 滑带渗透试验方案

Table 1. Scheme of the seepage tests for the sliding zone

试样编号	渗透压力/kPa	渗透循环周期	CT扫描周期节点
S1	0	0	0, 12
S2	10	12	0, 1, 3, 6, 12
S3	50	12	0, 1, 3, 6, 12
S4	100	12	0, 1, 3, 6, 12

下载: 导出CSV

参考文献(29)

[1]	唐军峰, 唐雪梅, 肖鹏, 等. 库水位升降与降雨作用下大型滑坡体渗流稳定性分析[J]. 地质科技通报, 2021, 40(4): 153-161. doi: 10.19509/j.cnki.dzkq.2021.0409 Tang J F, Tang X M, Xiao P, et al. Analysis of seepage stability of large-scale landslide under water-level fluctuation and rainfall[J]. Bulletin of Geological Science and Technology, 2021, 40(4): 153-161(in Chinese with English abstract). doi: 10.19509/j.cnki.dzkq.2021.0409
[2]	李长冬, 龙晶晶, 姜茜慧, 等. 水库滑坡成因机制研究进展与展望[J]. 地质科技通报, 2020, 39(1): 67-77. doi: 10.19509/j.cnki.dzkq.2020.0108 Li C D, Long J J, Jiang Q H, et al. Advance and prospect of formation mechanism for reservoir landslides[J]. Bulletin of Geological Science and Technology, 2020, 39(1): 67-77(in Chinese with English abstract). doi: 10.19509/j.cnki.dzkq.2020.0108
[3]	Tang H M, Li C D, Hu X L, et al. Deformation response of the Huangtupo landslide to rainfall and the changing levels of the Three Gorges Reservoir[J]. Bulletin of Engineering Geology and the Environment, 2015, 74(3): 933-942. doi: 10.1007/s10064-014-0671-z
[4]	Skempton A W. Residual strength of clays in landslides, folded strata and the laboratory[J]. Geotechnique, 1985, 35(1): 3-18. doi: 10.1680/geot.1985.35.1.3
[5]	李华斌. 滑坡滑带土微结构的定量研究及其应用[D]. 北京: 中国地质科学院, 1992. Li H B. The quantitative research of soil micro-structure on sliding zoon of landslide and its application[D]. Beijing: Chinese Academy of Geological Sciences, 1992(in Chinese with English abstract).
[6]	严春杰, 唐辉明, 陈洁渝, 等. 三峡库区典型滑坡滑带土微结构和物质组分研究[J]. 岩土力学, 2002, 23(增刊1): 23-26. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX2002S1007.htm Yan C J, Tang H M, Chen J Y, et al. Studies of soil microstructures and compositions of slipping zone in reservior district of Three Gorges Profect[J]. Rock and Soil Mechanics, 2002, 23(S1): 23-26(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX2002S1007.htm
[7]	杨德欢, 韦昌富, 颜荣涛, 等. 细粒迁移及组构变化对黏土渗透性影响的试验研究[J]. 岩土工程学报, 2019, 41(11): 2009-2017. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201911007.htm Yang D H, Wei C F, Yan R T, et al. Experimental study on effects of fine particle migration and fabric change on permeability of clay[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(11): 2009-2017(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201911007.htm
[8]	李守定, 李晓, 张年学, 等. 三峡库区宝塔滑坡泥化夹层泥化过程的水岩作用[J]. 岩土力学, 2006, 27(10): 1841-1846. doi: 10.3969/j.issn.1000-7598.2006.10.041 Li S D, Li X, Zhang N X, et al. Water-rock interaction of clay gouged intercalation sludging process of baota landslides in Three Gorges reservoir area[J]. Rock and Soil Mechanics, 2006, 27(10): 1841-1846(in Chinese with English abstract). doi: 10.3969/j.issn.1000-7598.2006.10.041
[9]	曹玲, 罗先启. 三峡库区千将坪滑坡滑带土干-湿循环条件下强度特性试验研究[J]. 岩土力学, 2007, 28(增刊1): 93-97. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX2007S1019.htm Cao L, Luo X Q. Experimental study of dry-wet circulation of Qianjiangping Landslide's unsaturated soil[J]. Rock and Soil Mechanics, 2007, 28(S1): 93-97(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX2007S1019.htm
[10]	Jiao Y Y, Song L, Tang H M, et al. Material weakening of slip zone soils induced by water level fluctuation in the ancient landslides of Three Gorges Reservoir[J]. Advances in Materials Science and Engineering, 2014, 2014(9): 20234.
[11]	江强强, 刘路路, 焦玉勇, 等. 干湿循环下滑带土强度特性与微观结构试验研究[J]. 岩土力学, 2019, 40(3): 1005-1012, 1022. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201903020.htm Jiang Q Q, Liu L L, Jiao Y Y, et al. Strength properties and microstructure characteristics of slip zone soil subjected to wetting-drying cycles[J]. Rock and Soil Mechanics, 2019, 40(3): 1005-1012, 1022(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201903020.htm
[12]	Burton G J, Pineda J A, Sheng D, et al. Microstructural changes of an undisturbed, reconstituted and compacted high plasticity clay subjected to wetting and drying[J]. Engineering Geology, 2015, 193: 363-373.
[13]	Deng Y F, Yue X, Liu S, et al. Hydraulic conductivity of cement-stabilized marine clay with metakaolin and its correlation with pore size distribution[J]. Engineering Geology, 2015, 193: 146-152.
[14]	王鲁男. 不同含水率与剪切速率下滑带土残余强度特性研究[D]. 武汉: 中国地质大学, 2017. Wang L N. Residual Strength Behavior of Slip Soils under Different Moisture Contents and Shearing Rates[D]. Wuhan: China University of Geosciences, 2017(in Chinese with English abstract).
[15]	Wu Y P, Li L W, Feng X L, et al. Effect of cyclic wetting and drying on the microstructure of slip zone soils in Huangtupo landslide[J]. Journal of Engineering Science and Technology Review, 2016, 9(4): 209-216.
[16]	Ke L, Takahashi A. Strength reduction of cohesionless soil due to internal erosion induced by one-dimensional upward seepage flow[J]. Soils and Foundations, 2012, 52(4): 698-711.
[17]	Sato M, Kuwano R. Suffusion and clogging by one-dimensional seepage tests on cohesive soil[J]. Soils and Foundations, 2015, 55(6): 1427-1440.
[18]	Xu P P, Zhang Q Y, Qian H, et al. Microstructure and permeability evolution of remolded loess with different dry densities under saturated seepage[J]. Engineering Geology, 2021, 282: 105875.
[19]	Miao F S, Wu Y P, Li L W, et al. Weakening laws of slip zone soils during wetting-drying cycles based on fractal theory: A case study in the Three Gorges Reservoir(China)[J]. Acta Geotechnica, 2019, 15(7): 1909-1923.
[20]	Zuo L, Xu L, Baudet B A, et al. The structure degradation of a silty loess induced by long-term water seepage[J]. Engineering Geology, 2020, 272: 105634.
[21]	Dong H, Huang R Q, Gao Q F. Rainfall infiltration performance and its relation to mesoscopic structural properties of a gravelly soil slope[J]. Engineering Geology, 2017, 230: 1-10.
[22]	Nguyen C D, Benahmed N, Andò E, et al. Experimental investigation of microstructural changes in soils eroded by suffusion using X-ray tomography[J]. Acta Geotechnica, 2019, 14(3): 749-765.
[23]	武金博, 吴庆华. 三峡库区黄土坡滑带空隙结构与渗流特性[J]. 长江科学院院报, 2020, 37(9): 102-109. https://www.cnki.com.cn/Article/CJFDTOTAL-CJKB202009018.htm Wu J B, Wu Q H. Pore structure and seepage characteristics of slip zone of Huangtupo landslide in Three Gorges Reservoir area[J]. Journal of Yangtze River Scientific Research Institute, 2020, 37(9): 102-109(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-CJKB202009018.htm
[24]	de Oliveira J A T, Cássaro F A M, Pires L F. Quantification of the pore size distribution of a Rhodic Hapludox under different management systems with X-ray microtomography and computational simulation[J]. Soil and Tillage Research, 2021, 209: 104941.
[25]	Hu X L, Tang H M, Li C D, et al. Stability of Huangtupo riverside slumping mass Ⅱ# under water level fluctuation of Three Gorges Reservoir[J]. Journal of Earth Science, 2012, 23(3), 326-334.
[26]	罗红明, 唐辉明, 章广成, 等. 库水位涨落对库岸滑坡稳定性的影响[J]. 地球科学: 中国地质大学学报, 2008, 33(5): 687-692. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX200805015.htm Luo H M, Tang H M, Zhang G C, et al. The influence of water level fluctuation on the bank landslide stability[J]. Earth Science: Journal of China University of Geosciences, 2008, 33(5): 687-692(in Chinese with English abstract). https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX200805015.htm
[27]	Chang D, Zhang L. A stress-controlled erosion apparatus for studying internal erosion in soils[J]. Geotech. Test. J., 2011, 34(6): 579-589.
[28]	Xiao M, Shwiyhat N. Experimental investigation of the effects of suffusion on physical and geomechanic characteristics of sandy soils[J]. Geotech. Test. J., 2012, 35(6): 890-900.
[29]	Ke L, Takahashi A. Triaxial erosion test for evaluation of mechanical consequences of internal erosion[J]. Geotech. Test. J., 2014, 37(2): 347-364.