Study Of The Influence Of Different Types Of Plant Layout On Anchoring And Reinforcement Of Slopes

With the rapid development of society and economy,human beings have continuously increased the exloritation and utilization of rivers,which has caused a series of water ecological and environmental problems.In particular,the problem caused by channelized rivers is prominent,this phenomenon had resulted in the loss of key biological habitats or interruption of continuity.At the aim of making the revetment of the river bank not only meet the basic stability requirements of the slope,but also meet the ecological requirements of providing a good habitat for organisms and improving the river ecosystem,this research will adopt natural river ecological revetment technology,which uses plants and other natural materials as revetment materials.However,the current research on root system theory and the application of engineering practice have not achieved a good combination.Because the stability of ecological revetment is closely related to the planting density and plant combination,and the current reinforced anchorage of plant roots is mainly focused on root length,root angle and other root factors,there are few researches on root combination ecological revetment at present.Therefore,this article selected the two banks of the lower reaches of the Tiantang River in the floodplain of the Yongding River as the research area.Basing on the existing survey data,the root morphological distribution and characteristic parameters of grass,shrub and arbor vegetation were determined through field experiments.First,the herb root system parameters are used to verify the shallow stability of the bank slope under the action of the herb root system reinforcement by the limit equilibrium method based on the reinforcement theory,and then the root system parameters of the shrubs and trees have been measured to calculate the root elastic modulus and The maximum anchoring force of the arbor root system,and the calculated elastic modulus can be used as the input parameter of the subsequent finite element software ABAQUS simulation.Through the ABAQUS finite element analysis and calculation method based on the principle of strength reduction method,to clarify the stabilization effect of the shallow root reinforcement of the vegetation root system and the deep root anchoring effect on the bank slope soil,so as to better guide the design and application of ecological bank protection projects.The results of the study showed that:(1)About herbaceous plants: Within the range of soil depth 10～20cm,the stability safety factor of Astragalus bank slope’s shallow reinforcement shows a sharp increase trend.Among them,the maximum increase in the safety factor of the shallow bank slope can be reached 135.758%,located at a depth of 20 cm from the ground.This phenomenon shows that,the effect of Astragalus-soil reinforcement is the best,which is under this depth condition.(2)About shrub plants: At the time of each shrub combination with a plant spacing of0.65 m,the optimal shrub combination is Tamarix and Wild plum blossom;At the time of each shrub combination with a plant spacing of 0.75 m,the optimal shrub combination is Tamarix and Euonymus.(3)About arbor plants: When the Bauhinia of the slope is planted at the toe of the slope,and the Ulmus pumila of the top of the slope is planted at a distance of 1.8 m from the slope shoulder,the best anti-sliding anchoring effect is produced.When the Bauhinia of the slope is planted at a distance of 0.3m from the foot of the slope,as the distance between the flowering Ulmus pumila at the top of the slope and the shoulder of the slope increases,the root content of the soil layer below the slip surface also increases.The fibrous roots have an obvious reinforcing effect.