乔木种植位置对岸坡深层锚固作用的影响——以永定河泛区为例

由于植物生态护岸稳定性研究是开展岸坡绿化生态修复的核心，因此本文以永定河泛区中天堂河下游段两岸作为研究区域，探究该区域的不同类型乔木种植位置对岸坡整体锚固作用的影响，旨在确定坡地区域与坡顶区域最佳的乔木种植方案，以解决洪泛区湿陷性粉质粘土岸坡坡脚处易失稳的安全隐患。本研究采用拓扑根系描绘法、最大摩擦锚固力计算法、经验公式模型法以及ABAQUS有限元模拟法，分别对根系的形态、根系的固土性能、根系力学特性以及锚固岸坡整体稳定性进行分析。研究结果表明：（1）由于紫荆根系具有较为发达的须根，因而紫荆具有较强的锚固性能，相较于紫荆，榆叶梅锚固性能相对较差，在同一深度的埋置条件下，二者的锚固性能相差幅度为5%~25%；（2）当坡地区域的紫荆位于坡脚处，且坡顶区域的榆叶梅位于距离坡肩1.8m处的种植位置时，岸坡的安全系数达到2.153，岸坡的抗滑锚固效果可达到最佳。本研究认为坡顶区域与坡地区域的乔木种植位置可对粉质粘土坡体稳定产生双重耦合的影响，当坡地区域植株的种植位置处于坡脚处时，坡顶处任何区域的乔木根际土体均可与之形成有效的土拱效应，以遏制岸坡失稳。

Effect of Planting Position and Arbor Type on the Anchorage Depth of the Yongding River Floodplain Embankment

Because the key step of ecological embankment greening restoration lies in ensuring the stability of plant-ecological embankment, this paper takes the two banks of the Tiantang River downstream section as the research area, which is in the Yongding River floodplain and explores the impacting embankment stability factors, which is different types of arbors and different planting locations.The effect of planting locations on the overall anchoring embankment stability is investigated, which aims to determine the optimal planting scheme on the top and bottom regions of the slope and solve the potential instability hazard at the foot of the collapsible soil embankment in the flood area. In this study, three methods were employed to analyze the root morphology, soil-anchored performance of the root system, root mechanical characteristics and anchored-slope stability, which includes the root morphology topology method, maximum friction anchoring force calculation method, empirical formula model method and ABAQUS finite-element simulated method. These results shown that: (1)Because the root system of Cercis chinensis has more developed fibrous roots, it has strong anchoring capability. Compared with Cercis chinensis, Amygdalus triloba has relatively poor anchoring performance, under the same depth of embedding conditions, the extent of difference in anchored capacity of two kinds of arbors is 5%~25%; (2)The anti-sliding anchoring effect of the embankment can reach the best performance when the Cercis chinensis in the bottom area is planted at the foot of the slope, and the Amygdalus triloba in the top area is planted at a distance of 1.8m from the shoulder of the slope, the safety factor of the embankment reaches 2.153. This study shown that the planting position of the arbors which located at the region of the top and the bottom of the slope, can have a dual coupling effect on the stability of silty clay slope. When the planting position of the plant is at the foot of the slope, the rhizosphere soil of the arbor which located in any top areas of the slope, can form an effective soil arching effect with it for curbing embankment instability.