Evaluation And Prevention Of Seepage Of Water Seepage In No.14 Grottoe Of Yungang Grottoes

One of the most important reasons for flood,which influences stone relics weathering the most severely,is water seepage.Thus,the study of failure mechanisms and treatment schemes of water seepage becomes extremely important.Meanwhile,it acts on preventing water seepage of stone relics in our country as a reference.As one of the four largest grottoes,Yungang Grottoes also suffers water seepage.Among them,the water seepage in the No.14 Grottoe of Yungang Grottoes is the most serious in all grottoes.Therefore,this article takes the No.14 Grottoe of Yungang Grottoes as the research object,according to the geological exploration data and the indoor test data.By means of numerical simulation,the mechanism and prevention measures of water seepage disease in No.14 Grottoe are explored.The contents are as follows:1.Summarize the basic situation of Yungang Grottoes engineering geology and hydrological geology,analyzes the seepage mechanism of A and B seepage area of No.14 Grottoe of Yungang Grottoes.Water caused the water blocking effect of joint fissure seepage directly and sandy mudstone interlayer.2.Combined with the engineering geological and hydrogeological conditions in the area,through the SEEP/W module of Geostudio software in the three sections on the No.14 Grottoe to profile modeling under rainfall condition of pore water pressure and the three sections of the pressure head,the leakage area of the seepage flow,the underground water level were calculated.The influence of different rainfall intensity and different rainfall time on the change law of seepage field were analyzed.Through calculation and analysis,it was concluded that in the process of rainfall infiltration,pore water pressure and pressure head change are consistent in seepage process,and pore water pressure and pressure head change at joints and cracks are greater.In the condition of continuous rainfall,the daily seepage flow in the A and B leakage regions increases first to a fixed value with the increase of time.When the rainfall condition ceased,the daily seepage rate of the two leakage areas decreased at different rates.The B leakage area showed a significant lag phenomenon for the change of rainfall conditions.3.Combined with the actual working conditions of the No.14 Grottoe of Yungang Grottoes,and according to the simulation results,four preventive measures were analyzed and put forward:(1)Grouting with hydraulic lime grouting material.Combined with laboratory data for relevant indexes such as fluidity and shrinkage of hydraulic lime grouting material,reasonable ratio of water hard lime,metakaolin and quartz sand and water cement ratio are obtained.And using the SEEP/W module in the Geostudio software to simulate the seepage prevention effect after the grouting of the joint fracture zone.(2)The No.14 Grottoe roof waterproof blanket covered with GCL,and simulated to determine the scope of the permeability coefficient of impervious layer to achieve the best anti-seepage effect by using SEEP/W module of Geostudio software,the permeability coefficient of GCL is proved to meet the top cover waterproof blanket impervious layer anti permeability needs.(3)To set up the drainage ditch at the top of the No.14 Grottoe,the drainage effect of the natural gully on the east side of the No.14 Grottoe of Yungang Grottoes should be fully considered.(4)Monitoring measures of reasonable arrangement of internal industrial cameras,cave,block layout detector temperature sensor,to the real-time monitoring of the leakage in area,the implementation effect can be timely access to information leakage and waterproof engineering.