Effect Of Debris Flow Impact To The Uplift Pressure Of Base Of Check Dam

Uplift pressure of check dam is an important load and has an important influence on the stability of the dam.On the basis of the study on the seepage characteristics of debris flow soil,combined with the actual operation characteristics of dam,the impact of debris flow on dam and uplift pressure are studied,a series of simulation experiments are carried out and some research results are obtained:(1)Through the penetration experiments significantly influence the permeability of soil debris particles particle size is 0.1mm,and when the content of fine particles in the soil reached 20%,permeability to 10-5cm/s magnitude,belongs to low permeability level.In addition,the compaction experiment shows that the maximum dry density of the soil is the largest and the porosity is the smallest when the optimum fine particle content of the 15.68%~16.92%.(2)Fluid properties has a great influence on the impact of debris flow,debris flow is 2.0 g/cm3 when the fluid flow,integrity and comprehensive optimal,is the best,under various conditions of this experiment,the impact force of debris flow are the largest.The impact force of debris flow increases with the increase of volume,and exhibits a linear relationship.The impact force of debris flow decreases with the decrease of slope gradient,and the slope has a greater impact on the characteristics of debris flow.(3)After the impact of check dam,due to the elevation of the dam,the uplift pressure change at the same time,and rich the peak value in the moment,the peak value of the data compared with the former,the average increase of 3.02 times.After impact,debris flow deposition in front of the dam,the dam seepage channel is blocked,the uplift pressure gradually return to zero.(4)Check dam bottom bed material evenly,gently,in the base of the horizontal aspect,the uplift pressure value,variation and variation trend are consistent.In the base of the vertical aspect,the uplift pressure peak data and increment were decreases gradually from front to back of dam,and has a good linear relationship,the more close to the greater the surface uplift pressure increment,the effect is more significant.(5)After the debris flow is impacted by debris flow,the evolution law of the uplift pressure of the dam is that it increases with the impact of debris flow and decreases and return to zero with the sedimentation of debris flow.