Citation

You Y, Liu J, Chen X. Disaster Adv. 2012; 5(4): 241-249.

Copyright

(Copyright © 2012, Shankar Gargh)

DOI

unavailable

PMID

unavailable

Abstract

Many barrier dams formed around the epicenter when the Wenchuan earthquake occurred. The outburst flood of barrier lakes seriously threatens the safety of people and property downstream. Sluiceway channel is the most commonly used barrier lake hazard mitigation measure. Therefore, how to choose the cross section size to let the sluiceway have the optimal drainage capacity is very important. This study applies the Zongqu barrier dam as an example for discussing the optimal cross section design for the sluiceway channel. Based on the general background and filed investigation, the basic characteristics of the barrier dam are analyzed. Then, the peak discharge of 3.21 outburst flood is calculated. At last, the cross section size parameter (beta) and the cross section characteristic parameter (M) under the optimal cross section condition are introduced. The hydraulic radius (R) of the sluiceway channel with optimal discharge, the depth of sluice channel (h) and the bottom width (b) are deduced when the discharge of the outburst flood (Q) and the longitudinal gradient (I) are known. The results indicate that debris flows formed from the original landslide and residual materials are the main reason for the partial outburst of the barrier dam in March 21, 2009. According to the calculating results, the peak discharge of the outburst flood in the dam site was 318.8 m(3)/s. As a result, the cross section width is 6.13 m and the depth is 4.96 m of the Zongqu barrier dam sluice channel under the condition of optimal overflow.