资源描述:
《土木工程防灾减灾概论大论文》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、土木工程防灾减灾摘要泥石流是由于降水(暴雨、融雪)而形成的一种挟带大量泥砂、石块等固体物质的固液两相流体,呈黏性层流或稀性紊流等运动状态,是高浓度固体和液体的混合颗粒流。典型的泥石流由悬浮着粗大固体碎屑物并富含粉砂及黏土的黏稠泥浆组成。在适当的地形条件下,大量的水体浸透山坡或沟床中的固体堆积物质,使其稳定性降低,饱含水分的固体堆积物质在自身重力作用下发生运动,就形成了泥石流。其暴发突然、历时短暂、来势凶猛,具有极强的破坏力,是一种灾害性的地质现象。泥石流的主要危害是冲毁城镇、矿山、乡村,造成人畜伤亡,破坏房屋及其他工程设施,破坏农作物、林木及耕地。此外,泥石流有时也会淤塞河道,不但阻断航运,
2、还可能引起水灾。影响泥石流强度的因素较多,如泥石流容量、流速、流量等,其中泥石流流量对泥石流成灾程度的影响最为主要。此外,多种人为活动也在多方面加剧这上述因素的作用,促进泥石流的形成。本次论文主题就是泥石流,以舟曲特大泥石流为例子进行有关的分析与阐述。关键词:泥石流,降水,泥沙,灾害,流体,地质ABSTRACTDebrisflowisduetotheprecipitation(rainandsnowmelt)formedbyafloodofsolidmaterialsuchasclaysand,stonesofsolid-liquidtwo-phasefluid,aviscouslamina
3、rordiluteturbulentmotion,suchasistheflowofhighconcentrationsofthemixtureofsolidandliquidparticles.Typicaldebrisflowbythefloatbulkysoliddebrisandrichsiltandclaystickymud.Intheappropriateterrainconditions,alargeamountofwatertosoaktheslopesorsolidaccumulationofgullybedmaterial,makeitsstabilityisreduce
4、d,thehydratedsolidpackingmaterialmovement,undertheirowngravityhasformedmudslides.Itsoutbreaksuddenly,briefly,aggressive,withastrongdestructivepower,isaseveregeologicalphenomenon.Landslidesarethemainhazardsofdestroyedtown,mines,rural,humanandanimalcasualties,destructionofhousesandotherengineeringfac
5、ilities,damagecrops,forestsandfarmland.Inaddition,thedebrisflowsometimessiltationofriverchannel,notonlyblocktheshipping,maycausefloods.Factorsthataffectdebrisflowintensityismore,suchasdebrisflowcapacity,flowvelocity,flow,thedebrisflowinfluenceonthedegreeofdebrisflowbymostmajor.Inaddition,avarietyof
6、humanactivitieshascontributedinmanyaspectsthattheroleoftheabovefactors,promotetheformationofdebrisflow.Thisthesisisthedebrisflow,withheavyzhouqumudslideasexampletoanalysisandelaboration.Keywords:Mudslides,precipitation,sediment,disasters,fluid,geology10土木工程防灾减灾目录摘要………………………………………………………………………………………1
7、Abstract…………………………………………………………………………………1第1章概况……………………………………………………………………………41.1选题的背景………………………………………………………41.2灾害详情…………………………………………………………………………41.3本章小结……………………………………………………………………4第2章泥石流灾害成因………………………………………………………