Study On The Scale Amplification Of Debris Flow Caused By Cascading Barrier Dam Failures

Debris flow has now become one of our major geological disasters, this kind of disasters can cause clogging rivers, burying villages and destroying hazardous building factories and mines, resulting in significant economic losses and casualties. Debris flow refers to the rugged terrain of the mountains or valley deep va lleys and other areas, the rain, snow or other natural disaster caused by landslides and carry a lot of sediment and rocks special flood. If the torrents flow into the channel within the outburst sparked continuous barrier dam, the dam would flood a continuous burst of debris flow scale- up, very likely to cause large debris flows in a very short period of time.In this paper, seven ditch, for example, "5.12" earthquake triggered a large number of collapse, landslides and other geological disasters, which form a large accumulation of body clogging the dam in the channel. July 10, 2013, Wenchuan County seven ditch due heavy rain caused flood, flood upstream tributary to cause damming dam burst, the sudden flood of high-strength generated by the main groove and then the dam burst, and finally result in large debris flows.Continuous process and mudslides outburst scale amplification dam after dam damming research, the study of debris flow hazard characterization has important scientific theoretical significance, but also has practical value for continuous outburst debris flow management.Based on field exploration, field debris flow deposit in the body for the study, the use of indoor physical test methods, in-depth study of a continuous barrier dam outburst of mudslides and dam-scale amplification parameters(particle size distribution and the initial moisture content of dam) on amplification, and finally we obtained the following results and understanding:(1) when the upstream barrier dam burst, producing large amounts of surging floods, and increasing the potential of the substance within the channel, increasing the conversion of kinetic energy from the fluid, resulting in dam burst generated peak flows so large that mudslides enlarged scale.(2) continuous outburst barrier dam, the dam burst damage in the form of overtopping outburst, which is the instantaneous outburst overtopping, dam outburst floods will be Passing scoured the whole dam slope erosion, short duration dam almost no penetration and piping effect.(3) according to the different flume slope of weir dam in continuous burst test, when the flume slope is 5 degrees, the dam burst of energy magnification is about 2 times, debris flow scale amplification is not particularly large; when the slope of the flume is 18 DEG, continuous dam break energy amplification ratio is greater, the debris flow scale amplification effects are more obvious.(4) dam material continuous barrier dam outburst to a certain extent due to the size of the debris flow, wherein the aqueous dam different situations, to scour the debris flow in the stream, the greater the initial water content of the dam, energy outburst the higher the magnification, the size of the debris flow amplificat ion effect is more obvious.(5) dam gradation characteristics of D50 and uniformity coefficient(C u) as a reference value, with the increase of D50, uneven coefficient increases, the outburst energy amplification multiples of the maximum, the debris flow scale amplification effect has a greater impact. Illustrate the median particle size, large dam break is obvious on the continuous amplification effect of debris flow scale.