Study On Infiltration Law Of Ecological Bag Slope Protection Under Heavy Rainfall

In this thesis,vegetation ecological bag support and non-vegetation ecological bag support are respectively set up in the model tests of heavy rainfall slope under two kinds of slopes in order to provide certain theoretical support and technical basis for the application of ecological bag slope protection in similar projects.The conclusions are as follows:(1)Through a vegetation ecological support with no vegetation ecological bag bag of model experiment,found that vegetation ecological bag support of volumetric water content mutation rate because of roots and soil interface flow soil infiltration of rainwater and become more faster,different position of infiltration rate were similar and the ascent rate of pore water pressure may be due to the slope slower development of transient saturated zone and slow,The slow development of pore water is beneficial to the stability of slope.However,this effect is not obvious in higher slope.(2)Infiltration model was used to analyze the height of infiltration front.It is found that these model values are higher than the experimental values of the infiltration front height measured in the actual test in the same time.The assumed conditions are too perfect and the test parameters will be affected under different vegetation conditions.(3)The working condition of heavy rainfall under eco-bag support was established by finite element analysis software Geostudio,and the changes of hydrological characteristics of slope under eco-bag support under heavy rainfall were studied.It is found that the role of ecological bag in preventing heavy rainfall erosion is to replace the slope to produce transient saturated area,especially in the case of vegetation growth.Both in terms of the rising trend of volumemoisture content and the appearance time of transient saturation zone,the infiltration rate of slope is faster than that of slope bottom,and the slope is more worthy of attention in the aspect of rainwater infiltration protection.(4)Combined with the actual engineering and test results,a slope value range of30 ° ～40 ° for ecological bag support can be determined,and the early warning method for slope under ecological bag support by rainfall is proposed: using the volume moisture content,saturation,cumulative infiltration amount and damage time to carry out early warning protection.In the initial stage of eco-bag support,water content of 31% and saturation of 60% are judged to reach the safety warning value,while in the later stage,after the completion of plant growth,water content of 37%and saturation of 70% are taken as the warning value.In addition,the comparison table of infiltration amount and corresponding failure time under different conditions is listed to provide the basis of early warning value for practical engineering.