干湿作用下紫色土埂坎裂隙开闭演化特征

doi:10.16843/j.sswc.2022.02.003

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Abstract [Background] Soil bund has been widely constructed as important soil conservation practice on sloping farmlands in the purple-soil area, while the stability of the soil bund affects its soil conservation benefits. The propagation and closure evolution of cracks reduces the stability of soil bund following drying and wetting alternations, thereby affecting the associated soil conservation benefit provided. This study aims to reveal the propagation and closure evolution pattern of cracks developed on purple-soiled bund following alternative drying and wetting condition using indoor simulation test, and to determine the relationship between crack evolution and stability of soil bund. [Methods] Undisturbed soil samples were collected from in-situ sloping farmland soil bund in Xiema town, Beibei district, Chongqing. Alternative drying and wetting was simulated in the laboratory, then the cracks images were extracted dynamically, Photoshop and image software were used to calculate the characteristic parameters of cracks (area density, area-perimeter ratio, shape index and fractal dimension). [Results] 1) During the drying process, the cracks intensity (area density and area-perimeter ratio) and complexity (shape index and fractal dimension) firstly increased significantly (1-9 d) and then slowly increased to a stable state (>9-15 d), while cracks intensity and complexity indexes showed a significant positive correlation (P<0.01). 2) During the wetting process, the evolutionary process of cracks morphology could be divided into 3 stages, i.e., (Ⅰ) secondary cracks closure stage, (Ⅱ) cracks intersection disconnection stage, and (Ⅲ) main cracks narrowing stage. The overall average declining rate of cracks intensity and complexity were 87% and 61%, respectively, following a sequence of stage Ⅰ (62%)>stage Ⅱ (47%)>stage Ⅲ (33%), and stage Ⅰ (52%)>stage Ⅱ (18%)>stage Ⅲ (17%) for cracks complexity. 3) The average values of cracks intensity and complexity was proportional to the number of wetting and drying alternations. During the initial two wetting and drying alternations, the cracking degree and network complexity changed sharply, and then gradually decreased, reached the maximum after the 4th of alternation, and the bunds peel appeared at the 5th wetting process. [Conclusions] This study shows that propagation and closure evolution of cracks subjected to alternative drying and wetting is an important factor reducing the stability of the soil bunds. With the increase of the number of the alternations, the evolution intensity and network complexity of cracks gradually increase, leading to the instability of the soil bunds. This findings can provide implications for the construction and maintenance of purple soil bunds for soil conservation purpose.

Key words： bunds crack propagation and closure drying and wetting alternation purple soil

Received: 11 January 2021

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S157.3+2

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	Articles by authors
	CHEN Shuxiang
	WEI Jie
	LUO Huajin
	GAN Fengling

Cite this article:

CHEN Shuxiang,WEI Jie,LUO Huajin, et al. Evolution pattern of propagation and closure of cracks in the purple-soiled bunds following alternative drying and wetting treatments[J]. SSWC, 2022, 20(2): 15-23.

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http://journal12.magtechjournal.com/Jweb_stbc/EN/10.16843/j.sswc.2022.02.003 OR http://journal12.magtechjournal.com/Jweb_stbc/EN/Y2022/V20/I2/15

[1]	韦杰,史炳林,李进林.紫色土坡耕地埂坎土壤抗剪性能对含水率的响应[J].农业工程学报,2016,32(20):153. WEI Jie, SHI Binglin, LI Jinlin. Response of soil shear strength to soil water content in purple soil slope cropland bunds[J]. Transactions of the CSAE, 2016, 32(20):153.
[2]	李进林,韦杰.三峡库区坡耕地埂坎类型、结构与利用状况[J].水土保持通报,2017,37(1):229. LI Jinlin, Wei Jie.Types, structure and utilization of fieldridges on sloping farmland in Three Gorges Reservoir Region, China[J]. Bulletin of Soil and Water Conservation, 2017, 37(1):229.
[3]	YUE Yan, ZHEN Huaicai, ZHAI Xingyu, et al. The role of vegetation on earth bunds in mitigating soil erosion in Mollisols region of Northeast China[J]. Catena, 2021, 196:104927.
[4]	李胜龙,易军,刘目兴,等.稻田-田埂过渡区土壤优先流特征研究[J].土壤学报,2018, 55(5):1131. LI Shenglong, YI Jun, LIU Muxing, et al. Characteristics of preferential flow in the intermediate zone between paddy field and ridge[J]. Acta Pedologica sinica, 2018,55(5):1131.
[5]	赵景波,贺秀斌,邵天杰.重庆地区紫色土和紫色泥岩的物质组成与微结构研究[J].土壤学报,2012,49(2):212. ZHAO Jingbo, HE Xiubin, SHAO Tianjie. Material composition and microstructure of purple soil and purple mudstone in Chongqing area[J]. Acta Pedologica sinica, 2012,49(2):212.
[6]	殷宗泽,徐彬.反映裂隙影响的膨胀土边坡稳定性分析[J].岩土工程学报,2011,33(3):454. YIN Zongze, XU Bin. Slope stability of expansive soil under fissure influence[J]. Chinese Journal of Geotechnical Engineering, 2011, 33(3):454.
[7]	张雨灼,王柳江,刘斯宏,等.干湿循环下膨胀土边坡响应的模型试验[J].郑州大学学报(工学版),2015,36(6):114. ZHANG Yuzhuo, WANG Liujiang, LIU Sihong, et al. Model test on the performance of the expansive soil slope during wetting-drying cycles[J]. Journal of Zhengzhou University (Engineering Science), 2015, 36(6):114.
[8]	李文杰,张展羽,王策,等.干湿循环过程中壤质黏土干缩裂缝的开闭规律[J].农业工程学报,2015,31(8):126. LI Wenjie, ZHANG Zhanyu, WANG Ce, et al. Propagation and closure law of desiccation cracks of loamy clay during cyclic drying-wetting process[J]. Transactions of the Chinese Society of Agricultural Engineering,2015, 31(8):126.
[9]	包惠明,魏雪丰.干湿循环条件下膨胀土裂隙特征分形研究[J].工程地质学报,2011,19(4):478. BAO Huiming, WEI Xuefeng. Fractal research the crack characteristic expansive soil under wetting-drying cycle[J]. Journal of Engineering Geology,2011,19(4):478.
[10]	唐朝生,施斌,刘春,等.影响黏性土表面干缩裂缝结构形态的因素及定量分析[J].水利学报,2007,38(10):1186. TANG Chaosheng, SHI Bin, LIU Chun, et al. Factors affecting the surface cracking in clay due to drying shrinkage[J]. Journal of Hydraulic Engineering, 2007, 38(10):1186.
[11]	黎伟,刘观仕,汪为巍,等.湿干循环下压实膨胀土裂隙扩展规律研究[J].岩土工程学报,2014,36(7):1302. LI Wei, LIU Guanshi, WANG Weiwei, et al. Crack propagation law of compacted expansive soils under wetting-drying cycles[J]. Chinese Journal of Geotechnical Engineering, 2014, 36(7):1302.
[12]	MA Tiantian, WEI Changfu, YAO Chuanqin, et al. Microstructural evolution of expansive clay during drying-wetting cycle[J]. Acta Geotechnica, 2020(2/3/4):1.
[13]	唐朝生,王德银,施斌,等.土体干缩裂隙网络定量分析[J].岩土工程学报,2013,35(12):2298. TANG Chaosheng, WANG Deyin, SHI Bin, et al. Quantitative analysis of soil desiccation crack network[J]. Chinese Journal of Geotechnical Engineering, 2013, 35(12):2298.
[14]	骆赵刚,汪时机,杨振北.膨胀土湿干胀缩裂隙演化及其定量分析[J].岩土力学,2020,41(7):2313. LUO Zhaogang, WANG Shiji, YANG Zhenbei. Quantitative analysis on fracture evolution of expansive soils under wetting-drying cycles effect[J]. Rock and Soil Mechanics, 2020, 41(7):2313.
[15]	叶万军,万强,申艳军,等.干湿循环作用下膨胀土开裂和收缩特性试验研究[J].西安科技大学学报,2016,36(4):541. YE Wanjun, WAN Qiang, SHEN Yanjun, et al. Cracking and shrinking properties of expansive soil under wetting-drying cycles[J]. Journal of Xi'an University of Science and Technology, 2016, 36(4):541.
[16]	汪三树,刘德忠,史东梅,等.紫色丘陵区坡耕地生物埂的蓄水保土效应[J].中国农业科学,2013,46(19):4091. WANG Sanshu, LIU Dezhong, SHI Dongmei, et al. Analysis on the soil and water conservation benefits of four bunds at edges of sloping land in purple hilly area[J]. Scientia Agricultura Sinica,2013, 46(19):4091.