泥石流拦挡坝优化设计

拦挡坝设防高度决定着库容，因此确定合理的设防高度在拦挡坝的设计中极为重要。在坝址确定的情况下提高拦挡坝的设防高度可以加大库容，增强防治工程的抗灾能力，但其泄洪能力会受到影响，因此拦挡坝的库容与其泄洪能力是矛盾的。既有设计理论中泥石流峰值流量按照全流域面积汇水输沙总量计算，该理论认为每个拦挡坝的设计洪峰流量是相同的，而实质上对于流域面积大的泥石流沟，设置在上游、中游及下游的拦挡坝由于汇水面积的差异而导致泥石流峰值流量相差较大，本文作者提出了按有效汇流面积计算泥石流峰值流量的优化设计方法，用该方法设计的拦挡坝的溢流断面面积较小，从而达到提高设防高度，增大库容，提高拦挡坝的容灾能力。

OPTIMUM DESIGN OF DEBRIS FLOW RATAINING DAM

Debris flow activity is a hazards of water flow with soil, and rock fragments, which cause a serious property damage as well as loss of lives. The check dam structure is the most effective structure and always is used in debris flow prevention engineer, and the check dam occupies about 52 percents of prevention engineer structure. The volume of reservoir of check dam is determined by its defence height. Under the condition that the check dam location was fixed, the volume of reservoir will increase by the defence height improving, but the ability of excess flow will be influenced, so the ability of excess flow is conflicted with the reservoir volume of check volume. This paper discussed the design methods of check dam and pointed that the computation method of debris flow on Code. A new design idea is applied, which gives a new computation method of debris flow based on the effective conflux area instead of debris flow valley drainage area. The design with the new method will improve the volume of reservoir or save the cost of the check dam.