Study On The Application Of Slope Protection Technology Of Shrub-grass Mixed Plants In Railway Slope Engineering

With the vigorous development of my country’s railway industry,the stability of railway slopes and their protective measures are becoming more and more important.Traditional slope protection technology is easy to cause environmental damage,while shrub-grass mixed plant slope protection technology is an organic combination of slope protection and greening engineering.It can not only effectively improve the stability of railway slopes,but also beautify the land environment and prevent soil erosion.This paper relies on the scientific research project of Hunan Provincial Department of Education "Study on the Mechanism and Stability of Slope Supporting by Living Tree Stumps and Bamboo Anchor Rods"(Project No.18A162)and the physical engineering of ecological slope protection of Nanpeng Station on the East Loop of Chongqing Railway Hub.Using the method of combining field investigation and numerical simulation,the schemes of the Chongqing Railway Hub East Ring Project were compared and selected,and the effects of shrubs and plants on slope protection under different working conditions were analyzed.And based on the actual project effect and the comparison of key technical indicators,the corresponding conclusions are as follows:1.Based on field investigations at Nanpeng Station on the East Ring Line of Chongqing Railway Hub,plants were selected based on local weather and geological conditions in Chongqing,and herbaceous vetiver and bush black locust were selected for use in the ecological slope protection project of the east ring line of Chongqing Railway Hub.Considering the long-term ecological effects,hydrological effects,the effectiveness of the green landscape and the long-term sustainable stability of the slopes,the slope protection scheme of the east loop of the Chongqing railway hub is adjusted to a new type of ecological slope protection technical scheme of mixed shrub and grass.2.Taking an ecological slope protection technology demonstration project on the east loop of Chongqing railway hub as an example,numerical models of shrub-grass slope protection scheme,shrub-grass-retaining wall slope protection scheme and shrub-grass-lattice anchor slope protection scheme were established using MIDAS finite element software.The stability analysis of three different slope protection schemes was carried out,and the results showed that the shrub-grass slope protection scheme made the potential sliding area of the slope soil deeper and the plastic area smaller;When shrub-grass-lattice anchors are used for slope protection,the safety factor of the slope is the largest;the safety factor of shrub-grass-retaining wall protection is slightly larger than that of shrub-grass slope protection.3.According to the analysis of the calculation results of the MIDAS numerical simulation,it can be seen that the safety factor of the railway slope is increased by 20.25%by using the shrub and grass protection.The potential failure area on the top of the slope changes from shallow to deep,and the plastic area is reduced,which has a certain effect on the control of slope displacement.The use of shrub-grass-retaining wall slope protection has increased the safety factor of railway slope by 22.84%,which shows that the retaining wall has a greater influence on the stability of railway slope.The use of anchor rods and lattice support increased the safety factor of the railway slope by 29.41%,and the potential damage area at the top of the slope changed from shallow to deep,which has the most significant control effect on the slope displacement.4.Compared with the original plan,the new-type shrub-grass mixed ecological slope protection technology can increase the safety factor of embankment slope stability by about 51%,and the cutting slope can be increased by 23%-43%.The long-term stability of the slope using the new-type shrub-grass mixed ecological slope protection technology increases year by year with the growth of the slope plant growth age.Its early growth is faster,and the stability growth generally slows down after five years.The adoption of the new scheme has significant economic effects,saving project cost by 7%-17%and shortening construction period by 25%-30%.