Research on the characteristics and treatment measures of the Yuchi Gully debris flow in Pingwu County

Abstract:

The Wenchuan Earthquake on May 12th， 2008， triggered a large number of debris flow disasters， resulting in a significant number of casualties and huge economic losses. In the years following the earthquake， debris flow disasters in the disaster-stricken areas continued to occur frequently after several rainy seasons. This paper takes the debris flow in Yuchi Gully in Pingwu County as an example to study the formation conditions， basic characteristics， and control measures of mountain rainstorm-induced gully-type debris flows. The debris flow in Yuchi Gully is a viscous debris flow with a bulk density of 1.62 t/m3. Using the rainstorm-flood method， the peak flow rate at the gully mouth of the debris flow with a recurrence interval of 20 years is calculated to be 53.48 m3/s. The total volume of a single debris flow passing through is 25400 m3， and the solid material discharge of a single debris flow is 10500 m3. These data provide design parameters for the debris flow control project. Based on these data， a comprehensive control measure of “submerged sill group+slit dam+diversion channel+covered culvert+road surface restoration” is proposed， and it has achieved good control results. This measure has certain reference value for the design of control projects for similar rainstorm-induced gully-type debris flows， especially those with large longitudinal gradients， narrow channels， and no reservoir storage space.