Analysis Of The Influence Of Material Composition On The Scope Of Changbai Mountains Volcano Secondary Debris Flow

Changbai Mountains volcano secondary debris flow is the turbulent debris flow,This paper mainly studies its movement mechanism, can provide theoretical supportand guidance for the secondary disaster prevention, is the frontier theory of debrisflow fields. Numerical turbulent debris flow motion simulation is composite crosstheory research and mathematical calculation method of debris flow, computerscience, the application of computer science is a relatively new subject in research ondebris flow, there is more important significance of prevention and cure of thevolcano secondary debris flow.This artical comprehensively analysises the present research status at home andabroad, in the summary of previous research on debris flows, especially on the basicof the results of volcano secondary debris flow, detailing survey in changbai mountainarea, we got loose sediment distribution characteristics. Use of different samples inthe Changbai Mountain region, we carried out simulation experiments respectively,Studying of volcano clastic composition on the effect of debris flow depositionthickness and maximum accumulation area, based on phenomena and results of thelaboratory simulation experimental, starting from the volcano secondary debris flow,beginning, accumulation mechanism, analysis of the movement characteristics ofvolcano secondary debris flow, and establish the basic characteristics of debris flowmovement model.In order to explain the relationship between various physical quantities ofvolcano secondary debris flow in the process of movement, the solid-liquid mixturecomposed of debris and water assumed to follow a continuous, uniform, notcompressible fluid motion law of Newton, based on the mass conservation equationand the Naiver-stokes equation, derived from the two-dimensional mathematicalmodel of a simulation of debris flow movement, the two-dimensional mathematicalmodel can be solved on the finite difference method, based on C++language programto write computer program, according to the indoor simulation experiment, we get therelated parameters of debris flow, running and simulating the elevation and the range of graphics in MATLAB software, simulation of debris flow movement andaccumulation characteristics. Through indoor simulation experiment and numericalsimulation of debris flow model, made some conclusions:1、Debris flow source mixture along with the volcano clastic flow ratio increased,pumice and fine particle washed the maximum distance increased, debris flow fanarea increased, the maximum packing thickness decreased, the flow rate increased, theflow depth decreased, the outbreak of bulk decreased. So the greater of the mixturevolcano clastic flow ratio is, the greater the risk range of debris flow formation.2、When the lahars and pyroclastic flow according to the proportion of1:1mixture, with the increase of washing time, the maximum thickness of debris flow,alluvial fan area, scouring distance and debris erupted volume increased. Because itcontains a certain amount of pumice, debris flow to break bulk density is smaller thanthe debris flows in general, and the fan area and erosion distance is too large.3、Movement patterns of contrast experiment results and numerical simulation ofdebris flow, the characteristics and accumulation of debris flow as the following: thelahars and pyroclastic flow of different mixing ratios and different flushing time,whether from the debris flow trend, or from the debris thickness, fan area andmaximum accumulative length of l and l/b value, have shown the consistency andinterior the experimental simulation results are good, the average fitting rates ofaround90%.