【摘要】 震后环境下大颗粒堰塞坝溃决流量是设计溃决型黏性泥石流防治工程的关键参数。在宽顶堰流量计算公式的基础上,结合水静力学和流体力学,建立估算大颗粒堰塞坝溃决流量的堵溃模型。为解决如何确定堵溃模型中堵塞系数ω这一难点,通过多处溃决型黏性泥石流典型案例,回归分析堵塞系数ω与最大颗粒直径D的相互关系。最后采用2013年7月13日汶川县七盘沟溃决型黏性泥石流案例检验大颗粒堰塞坝堵溃模型适用性。结果表明:溃决流量堵溃模型中堵塞系数与最大颗粒直径成正比,在泥石流实地调查中,仅需确定泥石流携带的最大颗粒尺寸、潜在堰塞坝宽度和泥石流平均流速,即可快速预测潜在泥石流堵溃点处的溃决流量;七盘沟泥石流的溃决流量估算结果误差较小,为12%,说明大颗粒堰塞坝堵溃模型可用于估算震后地区溃决型黏性泥石流中大颗粒堰塞坝的溃决流量。更多还原

【Abstract】 The breaching discharge of large particle-sized landslide-dam after earthquake is the key parameter for the design of the prevention project for the breaching and viscous debris flow. Based on the discharge calculation formula of broad-crest weir,a breach-blocking model for estimating the breaching discharge of large particle-sized landslide-dam is established in combination with hydrostatics and fluid mechanics. In order to solve the difficulty of how to determine the blocking coefficient ωin the breachblocking model,the correlation between the blocking coefficient ωand the diameter of the largest particle D is regressively analyzed through the typical cases of several breaching and viscous debris flows. Finally,the applicability of the breach-blocking model for the large particle-sized landslide-dam is verified with the case of Qipangou Debris Flow——a breaching and viscous debris flow occurred in Wenchuan County on July 13,2013. The result shows that the blocking coefficient in the breach-blocking model for the breaching discharge of landslide-dam is proportional to the diameter of the largest particle,thus the breaching discharge at the breach-blocking point of potential debris flow can be quickly predicted by only determining the maximum particle size carried by debris flow,the width of potential landslide and the mean flow rate of the debris flow. The error of the estimation made on the breaching discharge of Qipangou Debris Flow is relatively smaller and is 12%,which is indicated that breach-blocking model for large particle-sized landslide-dam can be applied to the estimation of the breaching discharge of the large particlesized landslide-dam within the breaching and viscous debris flows in the region after earthquake.更多还原