作者中心
专家审稿
编委审稿
主编审稿
DETERIORATION LAW AND MICROSCOPIC MECHANISM OF HYDRAULIC CHARACTERISTICS OF UNDISTURBED LOESS IN ILI UNDER FREEZE-THAW ACTION
-
摘要: 新疆伊犁地区冻害严重，尤以滑坡灾害最显著，主要体现在冻融作用下原状黄土的水力特性劣化方面，然而其水力特性的劣化规律和微观机制目前并不明晰，因此本文开展了冻融前后伊犁原状黄土的水力试验和微观试验研究。结果表明：冻融作用使得黄土内部的胶结性和结构完整性遭受破坏，在原位有效应力施加于冻融后的原状黄土，后续加上水分浸泡后，黄土会产生更大变形，因而冻融后原状黄土的自重湿陷性系数增加和孔隙比减小。冻融作用会使得原状黄土内部产生大裂缝和大孔径，渗流过程中水分会从大裂缝和大孔隙流失，因而冻融后原状黄土的渗透系数增加。冻融循环中的冻胀作用使得原状黄土内部自由水变成冰体，产生膨胀作用，其会破坏原状黄土的胶结性和结构完整性，同时产生大裂缝和大孔径，最终造成原状黄土的剪切强度和黏聚力降低。反复的冻融使得土颗粒发生破坏、移位，形成较为复杂的接触形式，从而使得内摩擦角减小并不显著。Abstract: The freezing damage in Ili area of Xinjiang is serious,especially the landslide disaster is the most significant,which is mainly reflected in the deterioration of hydraulic characteristics of undisturbed loess under freeze-thaw action. However,the deterioration law and microscopic mechanism of hydraulic characteristics are not clear at present. Therefore,this paper carries out the hydraulic test and microscopic test of undisturbed loess in Ili before and after freeze-thaw. The results show that the cementation and structural integrity of loess are destroyed by freeze-thaw action. The effective stress in situ is applied to the undisturbed loess after freeze-thaw,and the loess would produce greater deformation after subsequent water immersion. Therefore,the self-weight collapsibility coefficient of undisturbed loess increases and the void ratio decreases after freeze-thaw. Freeze-thaw action would cause large cracks and large pore size inside the undisturbed loess,and water would be lost from large cracks and large pores during seepage,so the permeability coefficient of undisturbed loess would increase after freeze-thaw. The frost heaving effect in the freeze-thaw cycle makes the free water inside the undisturbed loess become ice,resulting in expansion,which would destroy the cementation and structural integrity of the undisturbed loess,and produce large cracks and large apertures,resulting in the shear strength and cohesion of the undisturbed loess. Repeated freeze-thaw makes soil particles damage,displacement,forming a more complex form of contact,so that the internal friction angle is not significantly reduced.
-
图 4 冻融前后黄土自重湿陷性系数
Figure 4. Self-weight collapsibility coefficient of loess before and after freezing-thawing
图 5 冻融前后试样孔隙比与渗透系数
Figure 5. Pore and permeability coefficient of samples before and after freezing-thawing
图 6 冻融前后试样的应力-应变曲线
Figure 6. Stress-strain curves of samples before and after freezing-thawing
图 8 莫尔应力圆、黏聚力以及内摩擦角
Figure 8. Molar stress circle, cohesion and internal friction angle
图 10 冻融前后电镜扫描照片
a. n=0(500倍)；b. n=12(500倍)
Figure 10. Scanning electron microscope photos before and after freezing
表 1 试验黄土的基本物理参数
Table 1. Basic physical parameters of test loess
含水率
w/%液限
LL/%塑限
PL/%比重
Gs密度ρ
/g·cm-3孔隙比
e6.00 28.04 17.99 1.70 1.32 1.09 
下载: 导出CSV
表 2 试验方案
Table 2. Test scheme
高度/mm 直径/mm 冻融次数 试验目的 40 61.8 0/4/8/12 冻融后渗透 80 39.1 0/4/8/12 冻融后剪切 80 39.1 0/12 冻融后微观
下载: 导出CSV
-
He Q. 2014. Research report on the law of landslide disaster in Ili Valley[R]. Xinjiang Uygur Autonomous Region: China Geological Survey. He Q. 2022. Ili valley loess engineering geological properties test and comparative analysis project results report[R]. Yili Valley, Xinjiang: China Geological Survey. Li G X, Zhang B Y, Yu Y Z. 2013. Soil mechanics[M]. Beijing: Tsinghua University Press. Liu K, Ye W J, Jing H J, et al. 2021. Microscopic damage identification and macroscopic mechanical response of loess in seasonal frozen areas[J]. Chinese Journal of Geotechnical Engineering, 43 (S1): 192-197. Liu L Q, Zhang W Y, Zhang B Y, et al. 2021. Effect of freezing-thawing cycles on mechanical properties and microscopic mechanisms of loess[J]. Hydrogeological & Engineering Geology, 48 (4): 109-115. Pan Z X, Yang G S, Ye W J, et al. 2020. Study on mechanical properties and microscopic damage of undisturbed loess under dry and wet cycles[J]. Journal Engineering Geology, 28 (6): 1186-1192. Wang K K. 2021. Stability mechanism of Yili loess slope under multiple freeze-thaw cycles[D]. Urumqi: Xinjiang University. Wang T X, Luo S F, Liu X J. 2010. Testing study of freezing-thawing strength of unsaturated undisturbed loess considering influence of moisture content[J]. Rock and Soil Mechanics, 31 (8): 2378-2382. Xiao D H, Feng W J, Zhang Z, et al. 2015. Research on the relationship between permeability and construction feature of loess under the freeze-thaw cycles[J]. Hydrogeological & Engineering Geology, 42 (4): 43-49. Xu J, Li C Y, Wang Z Q, et al. 2016a. Experimental analysis on the mechanism of shear strength deterioration of undisturbed loess during the freeze-thaw process[J]. Civil Engineering and Environmental Engineering, 38 (5): 90-98. Xu J, Wang Z Q, Ren J W, et al. 2016b. Experimental research on permeability of undisturbed loess during the freeze-thaw process[J]. Journal of Hydraulic Engineering, 47 (9): 1208-1217. Xu J, Wang Z Q, Ren J W, et al. 2017. Comparative experimental study on permeability undisturbed and remolded loess under freezing-thawing condition[J]. Journal of Engineering Geology, 25 (2): 292-299. Yang G S, You Z Y, Wu D, et al. 2019. Experimental study on the relation of undisturbed loess' pore size distribution and mechanical property under freezing-thawing environment[J]. Coal Engineering, 51 (3): 107-112. Ye W J, Qiang Y H, Jing H J, et al. 2022. Freeze-thaw cycle experiment of loess paleosol with different water content based on nuclear magnetic resonance[J]. Journal of Engineering Geology, 30 (1): 144-153. Zhang Y, Bing H. 2015. Experimental study on the effect of freeze-thaw cycles on porosity characters of silty clay by using mercury intrusion porosimetry[J]. Journal of Glaciology and Geocryology, 37 (1): 169-174. Zhao L Q, Yang G S, Wu D, et al. 2019. Micro structure and fractal characteristics loess under freeze-thaw cycles[J]. Chinese Journal of Underground Space and Engineering, 15 (6): 1680-1690. Zhao Q, Su L J, Liu H, et al. 2020. Investigation on the influence of freezing-thawing cycle on the permeability coefficient anisotropy of loess[J]. Journal of Glaciology and Geocryology, 42 (3): 843-853. Zheng G, Xu Q, Liu X W, et al. 2020. The Jichang landslide on July 23, 2019 in Shuicheng, Guizhou: Characteristics and failure mechanism[J]. Journal of Engineering Geology, 28 (3): 541-556. Zhu S N, Yin Y P, Wang W P, et al. 2019. Mechanism of freeze-thaw loess landslide in Yili River Valley, Xinjiang[J]. Acta Geoscientica Sinica, 40 (2): 339-349. 贺强. 2014. 新疆伊犁谷地滑坡成灾规律研究报告[R]. 新疆维吾尔自治区: 中国地质调查局. 贺强. 2022. 伊犁谷地黄土工程地质性质测试与对比分析项目成果报告[R]. 新疆伊犁谷地: 中国地质调查局. 李广信, 张丙印, 于玉贞. 2013. 土力学[M]. 北京: 清华大学出版社. 刘宽, 叶万军, 景宏君, 等. 2021. 季冻区黄土微观损伤识别与宏观力学响应研究[J]. 岩土工程学报, 43 (S1): 192-197. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2021S1037.htm 刘乐青, 张吾渝, 张丙印, 等. 2021. 冻融循环作用下黄土无侧限抗压强度和微观规律的试验研究[J]. 水文地质工程地质, 48 (4): 109-115. https://www.cnki.com.cn/Article/CJFDTOTAL-SWDG202104015.htm 潘振兴, 杨更社, 叶万军, 等. 2020. 干湿循环作用下原状黄土力学性质及细观损伤研究[J]. 工程地质学报, 28 (6): 1186-1192. doi: 10.13544/j.cnki.jeg.2019-423 汪凯凯. 2021. 多次冻融循环下伊犁黄土斜坡稳定性机制[D]. 乌鲁木齐: 新疆大学. 王铁行, 罗少锋, 刘小军. 2010. 考虑含水率影响的非饱和原状黄土冻融强度试验研究[J]. 岩土力学, 31 (8): 2378-2382. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201008005.htm 肖东辉, 冯文杰, 张泽, 等. 2015. 冻融循环作用下黄土渗透性与其结构特征关系研究[J]. 水文地质工程地质, 42 (4): 43-49. https://www.cnki.com.cn/Article/CJFDTOTAL-SWDG201504009.htm 许健, 李诚钰, 王掌权, 等. 2016a. 原状黄土冻融过程抗剪强度劣化机理试验分析[J]. 土木建筑与环境工程, 38 (5): 90-98. https://www.cnki.com.cn/Article/CJFDTOTAL-JIAN201605012.htm 许健, 王掌权, 任建威, 等. 2016b. 原状黄土冻融过程渗透特性试验研究[J]. 水利学报, 47 (9): 1208-1217. https://www.cnki.com.cn/Article/CJFDTOTAL-SLXB201609013.htm 许健, 王掌权, 任建威, 等. 2017. 原状与重塑黄土冻融过程渗透特性对比试验研究[J]. 工程地质学报, 25 (2): 292-299. doi: 10.13544/j.cnki.jeg.2017.02.004 杨更社, 尤梓玉, 吴迪, 等. 2019. 冻融环境下原状黄土孔径分布与其力学特性关系的试验研究[J]. 煤炭工程, 51 (3): 107-112. https://www.cnki.com.cn/Article/CJFDTOTAL-MKSJ201903025.htm 叶万军, 强艳红, 景宏君, 等. 2022. 基于核磁共振的不同含水率黄土古土壤冻融循环试验研究[J]. 工程地质学报, 30 (1): 144-153. doi: 10.13544/j.cnki.jeg.2020-466 张英, 邴慧. 2015. 基于压汞法的冻融循环对土体孔隙特征影响的试验研究[J]. 冰川冻土, 37 (1): 169-174. https://www.cnki.com.cn/Article/CJFDTOTAL-BCDT201501019.htm 赵鲁庆, 杨更社, 吴迪, 等. 2019. 冻融黄土微观结构变化规律及分形特性研究[J]. 地下空间与工程学报, 15 (6): 1680-1690. https://www.cnki.com.cn/Article/CJFDTOTAL-BASE201906012.htm 赵茜, 苏立君, 刘华, 等. 2020. 冻融循环对黄土渗透系数各向异性影响的试验研究[J]. 冰川冻土, 42 (3): 843-853. https://www.cnki.com.cn/Article/CJFDTOTAL-BCDT202003012.htm 郑光, 许强, 刘秀伟, 等. 2020.2019年7月23日贵州水城县鸡场镇滑坡-碎屑流特征与成因机理研究[J]. 工程地质学报, 28 (3): 541-556. doi: 10.13544/j.cnki.jeg.2020-083 朱赛楠, 殷跃平, 王文沛, 等. 2019. 新疆伊犁河谷黄土滑坡冻融失稳机理研究[J]. 地球学报, 40 (2): 339-349. https://www.cnki.com.cn/Article/CJFDTOTAL-DQXB201902010.htm -
点击查看大图
图(10) / 表(2)
计量
- 文章访问数: 114
- HTML全文浏览量: 47
- PDF下载量: 38
- 被引次数: 0
