| 复合植被根系作用对生态岸坡稳定性的影响 |
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| 引用本文： | 郝由之,赵进勇,路 明,王 琦,彭文启,陈 卓.复合植被根系作用对生态岸坡稳定性的影响[J].水生态学杂志,2020,41(3):42-50. |
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| 作者姓名： | 郝由之 赵进勇 路 明 王 琦 彭文启 陈 卓 |
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| 作者单位： | 中国水利水电科学研究院，北京 100036； 南京水利科学研究院,江苏南京 ２１０００９;;河北工程大学，河北 邯郸 056038 |
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| 基金项目： | 国家水体污染控制与治理科技重大专项(2018ZX07105-002)；水利部公益性行业科研专项（201501030）；水利部技术示范项目（SF201808）；中国水科院基本科研业务费专项（WE0145B532017） |
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| 摘 要： | 生态护岸中植被根系的固土护岸效果缺乏可测性和可控性,为了确定植物根系存在对岸坡稳定性提升的量化作用,以北京市永定河莲石湖段生态岸坡为试验区,测定生态岸坡上种植典型"草-灌-乔"植被根系的形态分布及特征参数,在根系参数测定结果的基础上分析生态岸坡稳定性。通过建立根系加筋作用的力学模型,并采用基于加筋理论的极限平衡法,对岸坡浅层稳定性进行分析计算,岸坡整体稳定性采用基于强度折减原理的ABAQUS有限元模型计算法。结果表明,草本和灌木根系的加筋作用有助于提升岸坡浅层土体的粘聚力、抗剪强度和稳定性;草本和灌木根系的加筋作用对岸坡整体稳定性的影响远小于乔木根系的锚固作用,乔木种植于坡脚处对岸坡稳定性的提高最有利,岸坡安全系数可提升5.16%;乔木根系长度是岸坡整体稳定性重要的影响因素,乔木根系长度由1 m增加至3 m,生态岸坡整体稳定安全系数较素土岸坡分别增加了1.25%和14.2%,且增强速率逐渐变大;在水位变动时,生态岸坡与素土岸坡相比,其稳定安全系数最高可提升7.87%。根据岸坡浅层稳定性及整体稳定性计算结果,可以明确植被根系浅根加筋作用及深根锚固作用对岸坡土体的稳固效果,从而确定各类植被的配置方式,为生态护岸工程设计与应用提供参考。
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| 关 键 词： | 生态护岸 植被根系 极限平衡法 有限元 岸坡稳定性 |
| 收稿时间： | 2018/10/1 0:00:00 |
| 修稿时间： | 2020/6/4 0:00:00 |
Effect of Plant Roots on River Bank Stabilization after Composite Vegetation Planting |
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| HAO You-zhi,ZHAO Jin-yong,LU Ming,WANG Qi,PENG Wen-qi,CHEN Zhuo.Effect of Plant Roots on River Bank Stabilization after Composite Vegetation Planting[J].Journal of Hydroecology,2020,41(3):42-50. |
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| Authors: | HAO You-zhi ZHAO Jin-yong LU Ming WANG Qi PENG Wen-qi CHEN Zhuo |
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| Affiliation: | (China Institute of Water Resources and Hydropower Research,Beijing 100036,P.R.China;Nanjing Hydraulic Research Institute,Nanjing 210009,P.R.China;Hebei University of Engineering,Handan 056038,P.R.China) |
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| Abstract: | The effect of roots on soil stabilization and revetment in ecological restoration is difficult to measure and control. In this investigation, exposed banks of the Lianshi Lake section of Yongding River in Beijing were chosen to study the quantitative effect of the plant root system on bank slope stability using a herb-shrub-tree pattern of vegetation. In this study, Cynodon dactylon (Bermuda grass) was selected as the herb, Forsythia suspensa (weeping forsythia) as the shrub and Ulmus pumila (Siberian elm) as the tree. Root system parameters measured included the morphological distribution and characteristics of the typical herbs, shrubs, and trees planted on the ecological slope. The shallow stability of the bank slope was calculated and analyzed based on the established mechanical model of root reinforcement, developed using the limit equilibrium method based on reinforcement theory. The overall stability of the river bank slope was calculated by the ABAQUS finite element model based on the strength reduction principle. Results show that root reinforcement by the herbs and shrubs improved the cohesion, shear strength and stability of the shallow soil on the river bank. The reinforcement provided by herb and shrub roots on the overall stability of the river bank was much smaller than the anchoring effect of the tree roots. The planting of trees at the foot of the slope was most beneficial to the improvement of the bank slope stability, and the safety factor of the bank slope increased by 5.16%. Tree root length was an important factor for overall bank slope stability. When the root length increased from 1 m to 3 m, the overall stability safety factor of the ecological bank slope, respectively increased by 1.25% and 14.2% compared to the bank without vegetation. Further, the enhancement effect gradually increased with root length. When the water level changed, the stability factor of the ecological bank increased by up to 7.87% compared to the bank without vegetation. Thus, the reinforcement and anchoring effect of the root system on bank soils can be better estimated by calculating the shallow and overall stability of the river bank. These results provide a reference for configuring the vegetation types during the design phase of ecological bank protection projects. |
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| Keywords: | ecological revetment vegetation root system limit equilibrium method finite element bank slope stability |
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