Study On The Stability Of Slope Protected By Geocell And Plant

As a new type of ecological slope protection technology,the geocell grass-planting protection can realize the safety protection of the slope and the restoration of the original slope ecology by utilizing the restraint of the geocell to the shallow soil and combining with the lateral connection and coverage of the plant root system of the geocell filling.Based on the background of drainage project in Beijing New Airport flight zone,theoretical analysis,laboratory model test and finite element simulation were carried out to study the effect of geocell on slope.Among them,the protection mechanism of geocell and slope plant to enhance slope stability is summarized through theoretical analysis,and the theoretical mechanics model and safety coefficient expression of geocell slope protection under rainfall conditions are deduced and established.Besides,through finite element simulation,the deformation law of soil mass and the stability change law of slope under the protection of bare soil slope and geocell are compared and analyzed.The applicability of geocell slope protection under different engineering conditions and environmental conditions is analyzed by changing engineering parameters and environmental parameters.Finally,the optimization analysis of slope protection design scheme is carried out by changing the relevant design parameters of geocell slope protection.Indoor simulated rainfall test shows that geocell has good soil consolidation and erosion resistance characteristics,and the performance is most obvious in the middle and late stages of rainfall.At the same time,with the increase of slope,the most serious slope erosion with or without protection is 1:1 and 1:1.25,respectively.Compared with the unprotected slope,when the slope is more than 1:1.5,the anti-erosion effect of geocell is more obvious,especially when the slope reaches 1:1.25.The results of finite element simulation shows that geocell protection can effectively reduce pore water pressure and plastic deformation of slope soil,and can also reduce the maximum displacement of slope soil by about one third compared with bare soil slope,thus significantly improving the stability of slope.The analysis of influencing factors of geocell slope protection shows that the critical rainfall intensity of slope can be increased by twice as much as that of bare soil slope,reaching5?10^-5m/s,and the critical slope can be raised from 1:1.25 to 1:1.The shear strength parameters of soil have obvious influence on the stability of slope,with the increase of internal friction angle and cohesion,the safety factor of slope increases linearly,while the deformation parameters of soil have little effect on the stability of slope.At the same time,the optimum design of geocell slope protection shows that the optimum welding seam spacing and height of geocell are 50cm and 20cm respectively,and the optimum distribution spacing of anchor is 1.5m.In addition,the research results also show that the material properties of geocell and the length of anchor rod have relatively little influence on the stability of slope protection when they change in a certain range around the design value.