水利学报
水利學報
수리학보
2014年
8期
892-902
,共11页
李天阳%何丙辉%雷廷武%陈展鹏%张怡
李天暘%何丙輝%雷廷武%陳展鵬%張怡
리천양%하병휘%뢰정무%진전붕%장이
汶川震区%滑坡堆积体%细沟侵蚀%土石混合%水动力学
汶川震區%滑坡堆積體%細溝侵蝕%土石混閤%水動力學
문천진구%활파퇴적체%세구침식%토석혼합%수동역학
Wenchuan Earthquake area%landslide%rill erosion%earth-rock mixed%hydrodynamics
野外测定汶川震区滑坡堆积体休止角、土石混合坡面容重、土壤(<2 mm)与碎石(2~7 mm)比例,以此作为模拟研究的参数范围,开展了室内土石混合高陡坡面放水冲刷试验,研究了不同流量、坡度与石土比例组合下的水动力学特征。结果表明:34°坡面各流量及36°坡面4 L/min组合下,全土情况的水流流速均显著大于含碎石情况下的水流流速,在36°坡面8 L/min,12 L/min情况下,含碎石情况的水流流速逐渐增大并超过全土情况;各组合水流流速均随冲刷时间的延长而减小。石土比例对雷诺数 Re的影响较复杂,在试验时段内各组合的水流基本属于过渡流或紊流。石土比例对弗劳德数 Fr的影响规律与流速相似,Fr随冲刷时间延长而逐渐从急流转变为缓流,其中含碎石情况相比全土情况表现更加明显。Darcy-weisbach阻力系数 f 随冲刷时间先缓慢增加后迅速增加再急速下降,全土情况下的 f值介于0.16~14.40,含碎石情况下 f值介于0.16~29.68。Darcy-weisbach阻力系数 f与 Re呈负相关关系。
野外測定汶川震區滑坡堆積體休止角、土石混閤坡麵容重、土壤(<2 mm)與碎石(2~7 mm)比例,以此作為模擬研究的參數範圍,開展瞭室內土石混閤高陡坡麵放水遲刷試驗,研究瞭不同流量、坡度與石土比例組閤下的水動力學特徵。結果錶明:34°坡麵各流量及36°坡麵4 L/min組閤下,全土情況的水流流速均顯著大于含碎石情況下的水流流速,在36°坡麵8 L/min,12 L/min情況下,含碎石情況的水流流速逐漸增大併超過全土情況;各組閤水流流速均隨遲刷時間的延長而減小。石土比例對雷諾數 Re的影響較複雜,在試驗時段內各組閤的水流基本屬于過渡流或紊流。石土比例對弗勞德數 Fr的影響規律與流速相似,Fr隨遲刷時間延長而逐漸從急流轉變為緩流,其中含碎石情況相比全土情況錶現更加明顯。Darcy-weisbach阻力繫數 f 隨遲刷時間先緩慢增加後迅速增加再急速下降,全土情況下的 f值介于0.16~14.40,含碎石情況下 f值介于0.16~29.68。Darcy-weisbach阻力繫數 f與 Re呈負相關關繫。
야외측정문천진구활파퇴적체휴지각、토석혼합파면용중、토양(<2 mm)여쇄석(2~7 mm)비례,이차작위모의연구적삼수범위,개전료실내토석혼합고두파면방수충쇄시험,연구료불동류량、파도여석토비례조합하적수동역학특정。결과표명:34°파면각류량급36°파면4 L/min조합하,전토정황적수류류속균현저대우함쇄석정황하적수류류속,재36°파면8 L/min,12 L/min정황하,함쇄석정황적수류류속축점증대병초과전토정황;각조합수류류속균수충쇄시간적연장이감소。석토비례대뢰낙수 Re적영향교복잡,재시험시단내각조합적수류기본속우과도류혹문류。석토비례대불로덕수 Fr적영향규률여류속상사,Fr수충쇄시간연장이축점종급류전변위완류,기중함쇄석정황상비전토정황표현경가명현。Darcy-weisbach조력계수 f 수충쇄시간선완만증가후신속증가재급속하강,전토정황하적 f치개우0.16~14.40,함쇄석정황하 f치개우0.16~29.68。Darcy-weisbach조력계수 f여 Re정부상관관계。
A set of indoor experiments on earth-rock mixed steep slope with scouring flow method were conducted, and then the rill hydrodynamics characteristics under different flow rates, slopes, ratio of earth and rock contents were measured based on the angle of repose, bulk density, and ratio of earth and rocks that measured in the field investigation. The results show that under each flow rate of 34° and 4L/min of 36°,the average flow velocities under earth are significant higher than that of earth-rocks mixed. Under the 8 L/min and 12 L/min of 36° , the average flow rates increase gradually and become higher than that of earth. The average flow velocities under all of the groups decrease with the scouring times flies. The ratio of earth-rocks affecting the Reynolds number is complex. The flow regime is almost transition flow and tur-bulent flow during the experimental time. The influence of ratio of earth and rocks on Froude number has the same rules with that on average flow rates. As time goes on,Froude number transforms from supercriti-cal flow to subcritical flow, especially the changes are obvious under the earth and rocks mixed. Dar-cy-weisbach friction increases slowly, and then increases rapidly, decreases sharply at last with scouring time flies. The Froude number is 0.16~14.40 under the earth and 0.16~29.68 under earth and rocks mixed. Darcy-weisbach friction has negative correlation with Reynolds number.