降雨入渗条件下炭质泥岩填料渗透侵蚀试验研究OA

To investigate the permeation erosion characteristics of carbonaceous mudstone fill,a large-scale seepage test apparatus independently developed was used to conduct permeation erosion tests on carbonaceous mudstone filled with different stone contents in gradually increasing hydraulic gradient conditions.The variation rules of permeability coefficient,fine particle erosion amount and local hydraulic gradient of carbonaceous mudstone filled with different stone contents were analyzed,and the particle gradation of the fill before and after the test was compared to reveal the evolution law of permeation erosion of carbonaceous mudstone fill.The results show that under the same hydraulic gradient,with the increase of the stone content,the permeability coefficient of the specimen first decreases and then increases,reaching the minimum when the stone content is 40%.The critical failure hydraulic gradient corresponding to the permeation failure of the specimen decreases with the increase of the stone content,and when the stone content is 70%,the critical failure hydraulic gradient is only 22.5%of that when the stone content is 30%.The cumulative erosion of fine particles increases significantly with the increase of hydraulic gradient.According to the change law of erosion rate over time,the permeation erosion process is divided into three stages,i.e.the rapid erosion stage,the slow erosion stage and the seepage failure stage.During the rapid erosion phase,fine-grained material accounts for 50%-60%of the total erosion volume.Along the seepage direction,the loss of fine particles within the specimen shows a significant non-uniform distribution,which can be divided into three zones,i.e.,the top active loss zone,the central dynamic equilibrium zone and the bottom secondary loss zone.The research results can provide theoretical support for the prevention and control of disasters in embankment projects caused by permeation erosion of carbonaceous mudstone fill.