Study On The Deep Layer Of Slag Debris Flow Prevention Measure

Debris flows are one kind of geological disasters, which break out suddenly andcause severe damages. Hougou, Shimian County,Sichuan lies in the Shimian miningarea, which is of complicated but fragile geological conditions. Due toover exploitation, the intensity of geological disasters in this area increases. The maingeological disaster caused by mining is debris flows. Besides storms, the main directfactors causing debris flowsare loose earth and rocks left in beds of the ravines suchas disposed mining rocks and slag.At present, disposed rocks and mine dumps arestill accumulating in the tailing area and loose solid substances are continuing toincrease in the beds and sides of the ravines.Therefore investigation on the hazards ofdebris flows must be strengthened and prevention of this natural disaster must beenhanced by taking effective disaster prevention and reduction engineering measureswhich target at greatly preventing debris flows and reducing losses.On July4th,2013, debris flow broke out in Hougou, Shimian, which destroyedits original prevention engineering measures. This thesis analyzes the three debrisflow forming conditions of Hougou through the background of Hougou water basinand the characteristics of its ravines.Which with artificiality,susceptibility,harmconcentration characteristics and controllability.Combined withtheanalysis of theformation conditionsof debris flowformationmechanism,Thedebrisflowchanneltypedebris flowswithslope debris flow.The main phenomenon are the slagerosin.On this basis, this thesis calculates the motion features of Hougou Debrisflow—its density, velocity, impact force and flow quantity as well as its abrasionforce and shear force on the ravine beds. A conclusion can be drew that July4thHougou Debris Flow is of20-year frequency with density of1.67t/m3, peak flow of134.8m3/s, overall impact force of6.63tf/m2and single impact force of90.36tf.Hougou Debris Flow is of severe destruction which seriously threatens the downstream residents and the safety of the buildings.Thus measuring is veryimportant.On the basis of analysis and calculation of Hougou Debris Flow movementcharacteristics, this thesis explains that the devices of the original preventionmeasures in Hougou are unreasonable by applying the debris flow water channelsimulator in the state key laboratory of geological disaster prevention and geologicalenvironmental protection of Chengdu University of Technology to simulate thecircumstances of different slopes and amounts influencing ravine incisions. Combinedwith the actual situation, this thesis proposes prevention scheme in view of Hougoudebris flow. The main method is to transporttailings and sources out of Hougou and tobuild Level1check dams in the source area which aims to steady ravine beds, reduceerosion, restrain the development of debris flows and hold back left sources that is ofpossible formation of debris flows. Meanwhile,drainage channels should be built atthe downstream channel of debris flow in purpose of disaster prevention andreduction.