Dynamic mechanism of river bank stability and analysis of ecological support scheme
ZHANG Xingcun, CHENG Yumeng, LI Tong, QI Zihan, HE Xiangchang, LUO Pizhao, WANG Yujie, WANG Yunqi
1. Three-Gorges Reservoir Area(Chongqing) Forest Ecosystem Research Station, School of Soil and Water Conservation, Beijing Forestry University, 100083, Beijing, China; 2. Three-Gorges Reservior Area(Chongqing) Forest Ecosystem Research Station, Ministry of Education, School of Soil and Water Conservation, Beijing Forestry University, 100083, Beijing, China
Abstract：[Background] In order to study the dynamic mechanism of bank stability under the condition of rainfall combined with water level fluctuation, a reasonable ecological slope protection scheme was designed. [Methods] In this study, the combination of field investigation, mechanical test and numerical simulation was used to reveal the characteristics of the slope stability changing with water level and the failure mechanism of the slope in the Beibei section of the Jialing River, and the key technical parameters of the "living wood pile slope protection" measures were discussed by comparing with traditional plant slope protection methods and engineering pile slope protection methods. [Results] 1) The stability of the river bank beach slope fluctuated with the rise and fall of water level, and the slope stability dropped rapidly during the water level fluctuation stage. The reason is that the external hydrostatic pressure of the slope unloaded with the rise and fall of water level, and the seepage pressure inside the slope pointing outward from the slope caused shallow damage to the middle slope. In summer and autumn, when the water level of the river dropped more than 3 m/d, the early warning of landslide disaster on the river bank and beach should be triggered. 2) When the live wood pile, pile diameter and pile angle were fixed, properly increasing the pile length and reducing the pile spacing will help limit the horizontal displacement of the slope. It was suggested that the pile configuration of the gentle slope of the river bank beach was the middle upper part between the warning water level and the normal water level, with the pile spacing D=2.3 m, pile length L=3.3 m. The stability of topsoil will be affected only when the pile length was closed to the potential sliding layer. 3) At the initial stage of the configuration of live wood piles under the optimized parameter configuration, the stability coefficient increased by 18.6% under the extreme conditions of water level fluctuation, which was 3.8 times of the effect of traditional grass and shrubs on slope consolidation. After the root system of wood piles was fully grown, the slope stability coefficient increased by 22.3%, which was 3.7% more than that of piles configured with the same configuration. [Conclusions] This paper studied the change of pore water pressure of bank slope under the conditions of rainfall and water level fluctuation, and compared the slope stability of different support measures of bank slope in the Jialing River section of the Three Gorges Reservoir. On this basis, the arrangement parameters of movable wooden piles were optimized to provide theoretical basis and technical support for the ecological protection of the riverside in the Three Gorges Reservoir area.
张兴存, 程雨萌, 李通, 祁子寒, 何相昌, 骆丕昭, 王玉杰, 王云琦. 河岸稳定性动态机理及生态支护方案分析[J]. 中国水土保持科学, 2023, 21(3): 156-164.
ZHANG Xingcun, CHENG Yumeng, LI Tong, QI Zihan, HE Xiangchang, LUO Pizhao, WANG Yujie, WANG Yunqi. Dynamic mechanism of river bank stability and analysis of ecological support scheme. SSWC, 2023, 21(3): 156-164.
FATAHI B, KHABBAZ H, INDRARATNA B. Bioengineering ground improvement considering root water uptake model[J]. Ecological Engineering,2010,36(2):222.
[2]
DALY E R, MILLER R B, FOX G A. Modeling streambank erosion and failure along protected and unprotected composite streambanks[J]. Advances in Water Resources,2015,81:114.
[3]
VANMOPPEN W, POESEN J, PEETERS P, et al. Root properties of vegetation communities and their impact on the erosion resistance of river dikes[J]. Earth Surface Processes & Landfoms,2016,41(14):2038.
[4]
LIANG T, BENGOUGH A G, KNAPPETT J A, et al. Scaling of the reinforcement of soil slopes by living plants in a geotechnical centrifuge[J]. Ecological Engineering,2017,109(B):207.
[5]
王云,付伟,吴万平,等.活木桩生态护坡结构设计与参数优化[J].公路,2015,60(6):228. WANG Yun, FU Wei, WU Wanping, et al. Design and parameters optimization of ecological slope protection structure based on live stakes[J]. Highway,2015,60(6):228.
[6]
江学良,赵富发,杨慧,等.一种活树桩-活体植物加筋土边坡支护结构及其施工方法:CN111305235A[P].2020-06-19. JIANG Xueliang, ZHAO Fufa, YANG Hui, et al. A living tree pile living plant reinforced soil slope support structure and its construction method:CN111305235A[P]. 2020-06-19.
[7]
顾小华,丁国栋,刘胜,等.一种新型的高速公路边坡生态防护技术[J].水土保持研究,2006, 13(1):106. GU Xiaohua, DING Guodong, LIU Sheng, et al. A new bioengineering technique for slope protection in expressway[J]. Research of Soil and Water Conservation,2006,13(1):106.
[8]
徐中华,锌逢光,陈锦剑,等.活树桩固坡对边坡稳定性影响的数值分析[J].岩土力学,2004,25(增刊2):275. XU Zhonghua, XIN Fengguang, CHEN Jinjian, et al. Numerical analysis of the stability of slopes reinforced by live staking[J]. Rock and Soil Mechanics,2004,25(S2):275.
[9]
赵欢乐,朱爱军,周鸿轲,等.活木桩联合草本防护边坡稳定性数值研究[J].水力发电,2019,45(12):37. ZHAO Huanle, ZHU Aijun, ZHOU Hongke, et al. Numerical study on slope stability of live stakes combined with herbs protection[J]. Water Power,2019,45(12):37.
[10]
冯国建,沈凡,王世通.护坡植物根系分布特征及抗拉强度研究[J].重庆师范大学学报(自然科学版),2013,30(2):115. FENG Guojian, SHEN Fan, WANG Shitong. Study on distribution characteristic and tensile strength of slope eco-engineering plant root[J]. Journal of Chongqing Normal University (Natural Science),2013,30(2):115.
[11]
李志,马强,胡刚,等.武神公路植物根系抗拉特性试验研究[J]. 湖北工业大学学报, 2019, 34(1): 1. LI Zhi, MA Qiang, HU Gang, et al. Test on tensile properties of plant roots along Wudang Mountain Shennongjia Highway[J]. Journal of Hubei University of Technology,2019,34(1):1.
[12]
岳军声,李辉.活木桩固土植草技术在公路土质边坡防护中的应用[J]. 公路交通科技:应用技术版, 2009(10):174. YUE Junsheng, LI Hui. Application of soil fixation and grass planting technology with live wood piles in highway soil slope protection[J]. Highway Traffic Science and Technology: Application Technology Edition,2009(10):174.
[13]
WEI Xinsheng, WEN Fan, CHAI Xiaoqing, et al. Field and numerical investigations on triggering mechanism in typical rainfall-induced shallow landslides: A case study in the Ren River catchment, China[J]. Natural Hazards,2020,103(2):2145.
[14]
褚铅波.基于FLAC3d的土质边坡稳定性及其抗滑桩加固研究[D].杭州:浙江大学,2013:1. Chu Qianbo. Research on stability of soil slope and anti-slide pile reinforcement based on FLAC3D[D]. Hangzhou:Zhejiang University,2013:1.
[15]
ITO T,MATSUI T,HONG W P. Design method for stabilizing piles against landslide:One row of piles[J]. Soils ＆Foundations,1981,21(1):21.
[16]
HASSISOTIS S,CHAMEAU J L,GUNARATNE M. Design method for stabilization of slopes with piles[J]. Journal of Geotechnical ＆ Geoenvironmental Engineering,1997,125(10):314.
[17]
刘瑞龙,汤艳春,艾芊,等.边坡稳定分析方法对比研究[J].价值工程,2018,37(2):204. LIU Ruilong, TANG Yanchun, AI Qian, et al. Comparative study of slope stability analysis methods[J]. Value Engineering,2018,37(2):204.
[18]
CAI F, UGAI K. Numerical analysis of the stability of a slope reinforced with piles [J]. Journal of the Japanese Geotechnical Society Soils ＆ Foundation,2008,40(1):73.
[19]
戴自航,彭振斌.土体滑坡治理的合理设计与计算[J].中南大学学报(自然科学版),2000,31(2):98. DAI Zihang, PENG Zhenbin. The reasonable design and calculation of curing earth slides[J]. Journal of Central South University (Science and Technology), 2000,31(2):98.
2023, Vol. 21 
