不同频度和强度的干湿循环对花岗岩红壤固结强度的影响

doi:10.16843/j.sswc.2023092

摘要
图/表
参考文献
相关文章 (15)

全文: HTML (1 KB)
输出: BibTeX | EndNote (RIS)

摘要南方频繁干湿交替环境是影响土体结构强度演化的重要因素。为系统探究干湿循环频度和强度对赣州花岗岩红壤固结强度的影响,本研究通过进行不同强度和频度干湿循环条件下的快速固结试验,确定干湿循环效应对固结强度变化的影响机制。结果表明:1)孔隙比随着荷载压力的增大呈现先快速减小后趋于平稳趋势,干湿循环加剧花岗岩红壤的压缩变形;2)土壤瞬时沉降量和主固结沉降量均随着干湿循环频度和强度作用增强而逐渐增加;3)花岗岩红壤干湿循环后的压缩系数在0.8~1.0之间,呈现高压缩性,且随着频度的增加压缩系数逐渐增大,7次循环后缓慢增加并趋于稳定;干湿循环频度和强度增加条件下固结系数均呈现连续下降趋势,使土体强度降低;4)干湿循环频度对固结系数和压缩系数变化作用最为显著(F=4 102.71,P < 0.001;F=508.40,P < 0.001)。研究结果说明季节性降雨干旱引发的干湿循环效应显著影响土体的固结强度,加剧岩土体失稳崩塌的风险。

	服务

	把本文推荐给朋友
	加入我的书架
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章
	任秋菊
	孙艺函
	魏玉杰
	陈新
	王佳鑫
	刘凌志
	张光辉
	蔡崇法

关键词 ：花岗岩红壤, 干湿循环频度, 干湿循环强度, 固结特性, 土壤侵蚀

Abstract：[Background] Erosion-induced collapse is the most intense and severe type of erosion in the southern tropical and subtropical regions of China. The combination of abundant water and high temperatures in this region leads to variations in soil moisture due to temperature and changes in rainfall intensity and frequency. These changes result in frequent cycles of wet and dry conditions, and increase the probability of collapse. As Gan county being an area with the highest, most concentrated, and clustered erosion intensity, this study was carried out in Gan county, Jiangxi province, with the aim of providing a theoretical basis for predicting the degree of occurrence and development trend of collapse erosion. [Methods] We collected the samples from the surface granitic red soil in the Jingouxing subwatershed characterized by a subtropical hilly-mountainous climate with concentrated rainfall from April to June, which was subjected to wetting-drying cyclic tests with different frequencies and intensities, followed by rapid consolidation tests. By analyzing the e-p curves and the amount of consolidation sedimentation, we summarized the changes in consolidation intensity of granite red soil during humidification and desiccation, as well as the change rule of consolidation intensity under different frequencies and intensities of wetting-drying cycles. [Results] 1) The porosity ratio demonstrated a trend of first rapid reduction with increasing loading pressure, followed by a tendency of stabilizing. Wetting-drying cycles intensified the compression deformation of granite red. During the first 7 cycles, the porosity ratio followed the pattern of medium intensity > low intensity > high intensity. After 7 cycles, porosity showed no clear intensity-related pattern, indicating stabilization in both soil compression and deformation. 2) With the increase in frequency and intensity of wetting-drying cycles, both instantaneous soil sedimentation and main consolidation sedimentation had a gradual increase. At the 10th cycle, there was a rebound in the increment of instantaneous sedimentation, reducing by 0.079 mm compared to the 7th wetting-drying cycle. The impact of wetting-drying alternations on the soil's instantaneous sedimentation diminished after 7 cycles. 3) The compression factor of the granite red soil after wettingdrying cycles ranged from 0.8 to 1.0, indicating high soil compressibility, and it increased slowly and stabilized after seven cycles. The factor of consolidation showed a continuous decreasing trend with the increase of the frequency and the decrease of the intensity of wetting-drying cycles, the soil structure was damaged, the intensity of the soil was reduced, and the degree of destruction of the soil tended to be complete after seven cycles. 4) The frequency of wetting-drying cycles had the most significant effect on the changes in consolidation and compression factors (F = 4 102.71, P < 0.001, F = 508.40, P < 0.001), but the effect of the interaction between frequency and intensity was weak (F = 6.57, P < 0.05; F = 2.32, P > 0.1). [Conclusions] After seven cycles of wetting and drying, the alternating wet and dry conditions result in a weakening impact on soil sedimentation and consolidation properties, sedimentation and consolidation properties of the soil diminish. There is a relatively weak interaction between the frequency and intensity of wetting-drying cycles. The results of the study indicate that seasonal precipitation and drought-induced wetting-drying cycles primarily affect soil consolidation intensity, enhance soil homogeneity, and exacerbate the risk of instability and collapse.

Key words： granitic red soil frequency of wetting-drying cycles intensity of wetting-drying cycle consolidation characteristics soil erosion

收稿日期: 2023-06-25

PACS:

S157.1

基金资助:国家自然科学基金面上项目“花岗岩风化土体裂隙演化机制及其对崩岗侵蚀的影响”(42277329);国家自然科学基金青年科学基金项目“干湿交替作用下非均质土体的变形与失稳机制”(41807065);华中农业大学大学生创新创业训练计划项目“PAM对花岗岩残积土理化性质及作物生长的改良效应”(202210504016)

通讯作者: 陈新(1996—),女,博士研究生。主要研究方向:岩土体稳定性与土壤侵蚀机理。E-mail:chenxin97@webmail.hzau.edu.cn E-mail: chenxin97@webmail.hzau.edu.cn

作者简介: 任秋菊(2002—),女,在读本科生。主要研究方向:土壤侵蚀与水土保持。E-mail:2720538611@qq.com

引用本文:

任秋菊, 孙艺函, 魏玉杰, 陈新, 王佳鑫, 刘凌志, 张光辉, 蔡崇法. 不同频度和强度的干湿循环对花岗岩红壤固结强度的影响[J]. 中国水土保持科学, 2024, 22(3): 28-35.
REN Qiuju, SUN Yihan, WEI Yujie, CHEN Xin, WANG Jiaxin, LIU Lingzhi, ZHANG Guanghui, CAI Chongfa. Effect of wetting-drying cycles of different frequencies and intensities on consolidation intensity of granite red soil. SSWC, 2024, 22(3): 28-35.

链接本文:

http://journal12.magtechjournal.com/Jweb_stbc/CN/10.16843/j.sswc.2023092 或 http://journal12.magtechjournal.com/Jweb_stbc/CN/Y2024/V22/I3/28

[1]	廖义善,唐常源,袁再健,等.南方红壤区崩岗侵蚀及其防治研究进展[J].土壤学报, 2018, 55(6):1297. LIAO Yishan, TANG Changyuan, YUAN Zaijian, et al. Research progress on benggang erosion and its prevention measure in red soil region of southern China[J]. Acta Pedologica Sinica, 2018, 55(6):1297.
[2]	辜婧瑶.干湿循环对崩岗区花岗岩红壤孔隙结构的影响[D].武汉:华中农业大学, 2021:4. GU Jingyao. Influence of wetting-drying cycles on pore structure of granite red soils in benggang erosional area[D]. Wuhan:Huazhong Agricultural University, 2021:4.
[3]	安然,孔令伟,张先伟,等.干湿循环效应下花岗岩残积土结构损伤的多尺度研究[J].岩石力学与工程学报, 2023, 42(3):758. AN Ran, KONG Lingwei, ZHANG Xianwei, et al. A multi-scale study on structure damage of granite residual soil under wetting-drying environments[J]. Chinese Journal of Rock Mechanics and Engineering, 2023, 42(3):758.
[4]	胡华,吴轩,张越.基于模拟试验的强降雨条件下花岗岩残积土斜坡滑塌破坏机理分析[J].中国地质灾害与防治学报, 2021, 32(5):92. HU Hua, WU Xuan, Zhang Yue. Experimental study on slope collapse characteristics of granite residual soil slope under heavy rainfall[J]. The Chinese Journal of Geological Hazard and Control, 2021, 32(5):92.
[5]	方瑾瑾,杨小林,冯以鑫,等.干湿循环后膨胀土力学特性的真三轴试验研究[J].岩石力学与工程学报, 2021, 40(5):1043. FANG Jinjin, YANG Xiaolin, FENG Yixin, et al. True triaxial experimental study on mechanical properties of expansive soils after drying and wetting cycles[J]. Chinese Journal of Rock Mechanics and Engineering, 2021, 40(5):1043.
[6]	徐彬,殷宗泽,刘述丽.膨胀土强度影响因素与规律的试验研究[J].岩土力学, 2011, 32(1):44. XU Bin, YIN Zongze, LIU Shuli. Experimental study of factors influencing expansive soil strength[J]. Rock and Soil Mechanics, 2011, 32(1):44.
[7]	张文.干湿和冻融耦合作用下重塑黄土压缩变形特性及微观特性试验研究[D].西安:长安大学, 2019:12. ZHANG Wen. Experimental study on compressive deformation and microscopic properties of remolded loess under coupling effect of dry-wet and freezing-thawing[D]. Xi忆an:Chang忆an University, 2019:12.
[8]	张光辉,魏玉杰,周小荃,等.干湿循环强度与频度对花岗岩红壤孔隙分布的影响[J].农业工程学报, 2022, 38(S1):106. ZHANG Guanghui, WEI Yujie, ZHOU Xiaoquan, et al. Effects of the intensity and time of wetting-drying cycles on the pore distribution of granite red soil[J]. Transactions of the CSAE, 2022, 38(S1):106.
[9]	黄渐佳.游离氧化铁对花岗岩残积土抗剪和固结强度的影响[D].武汉:华中农业大学, 2022:18. HUANG Jianjia. Impacts of fee iron oxide on shear and consolidation strength for granite residual soils[D]. Wuhan:Huazhong Agricultural University, 2022:18.
[10]	夏浩城,汪时机,李贤,等.非饱和砂质黏性紫色土固结特性研究[J].岩土工程学报, 2022, 44(S1):121. XIA Haocheng, WANG Shiji, LI Xian, et al. Consolidation characteristics of unsaturated sandy clayey purple soils[J]. Chinese Journal of Geotechnical Engineering, 2022, 44(S1):121.
[11]	汪儒鸿,周海清,吴润泽,等.土体的结构性对边坡突变失稳影响研究综述[J].水利与建筑工程学报, 2017, 15(6):64. WANG Ruhong, ZHOU Haiqing, WU Runze, et al. Review on the effects of soil structure on slope failure and instability[J]. Journal of Water Resources and Architectural Engineering, 2017, 15(6):64.
[12]	周小文,刘攀,胡黎明,等.结构性花岗岩残积土的剪切屈服特性试验研究[J].岩土力学, 2015, 36(S2):157. ZHOU Xiaowen, LIU Pan, HU Liming, et al. An experimental study of shear yield characteristics of structured granite residual soil[J]. Rock and Soil Mechanics, 2015, 36(S2):157.
[13]	宋洋,刘思源,王晨炟.含水率和干湿循环对原状黄土变形特性的影响[J].辽宁工程技术大学学报(自然科学版), 2021, 40(2):148. SONG Yang, LIU Siyuan, WANG Chenda. Analysis on influence of moisture content and drying and watering cycle on deformation characteristics of undisturbed loess[J]. Journal of Liaoning Technical University (Natural Science), 2021, 40(2):148.
[14]	王港,张先伟,刘新宇,等.厦门花岗岩残积土的压缩变形特性及其微观机制[J].岩土力学, 2021, 42(12):3291. WANG Gang, ZHANG Xianwei, LIU Xinyu, et al. Compression characteristics and microscopic mechanism of Xiamen granite residual soil[J]. Rock and Soil Mechanics, 2021, 42(12):3291.
[15]	SUN Yinlei, TANG Liansheng. Use of X-ray computed tomography to study structures and particle contactsof granite residual soil[J]. Journal of Central South University, 2019, 26(4):938.
[16]	汤连生,王昊,孙银磊,等.干湿过程中花岗岩残积土抗拉强度变化研究[J].岩土力学, 2022, 43(7):1749. TANG Liansheng, WANG Hao, SUN Yinlei, et al. Change of tensile strength of granite residual soil during drying and wetting[J]. Rock and Soil Mechanics, 2022, 43(7):1749.