论文部分内容阅读
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。
In the field, the angle of repose of the landslide stack in Wenchuan earthquake area, the bulk density of soil-rock mixed slope, the ratio of soil (<2 mm) to gravel (2 ~ 7 mm) were measured as the parameters of the simulation study. Surface water scouring test was carried out to study the hydrodynamic characteristics under the combination of different flow rates, slope and ratio of rock and soil. The results show that the flow velocities of the whole soil under the combination of the flow rate of 34 ° and 4 L / / min, the velocity of water flow with gravel increased gradually and exceeded that of the whole soil; the flow velocity of each combination of water flow decreased with the extension of erosion time. The influence of the proportion of rock and soil on the Reynolds number Re is complex. During the test period, the flow of each combination basically belongs to transitional flow or turbulent flow. The effect of stone proportion on Froude number Fr is similar to the flow rate. Fr gradually changes from rapid to slow flow with the increase of flushing time, and the condition of crushed stone is more obvious than that of the whole earth. The Darcy-Weisbach drag coefficient f increases slowly and then decreases sharply with the scouring time first. The f value ranges from 0.16 to 14.40 for all-terrain and f = 0.16 to 29.68 for gravel. Darcy-weisbach drag coefficient f and Re was negatively correlated.