资勒沟泥石流灾害及特征

DEBRIS FLOW DISASTER AND THE CHARACTERISTICS OF ZILE GULLY

1987年6月5日晨,资勒沟暴发了一场灾害性泥石流,沟口的公路桥和凉红道班被摧毁,致使5名道班工人死亡。该沟是一条暴发频率很低的泥石流沟。这场泥石流是由局地暴雨激发而引起的,雨强为55.2毫米/小时。泥石流为粘性,容重2.18吨/立方米,最大流量352.1立方米/秒,最大流速10—12米/秒,总冲出物方量约8万—9万立方米。

Zile Gully,situated in Ganluo County of Sichuan Province,is a I branch gully at the right bank of Niuri River of Dadu River system. In the morning of June 5,1987,a destructive debris flow occurred. The highway bridge at the gully debouch and the house of Lianghong Maintenance Crew were destroyed so that 5 maintenance workers got killed and the direct economic losses were 150,000yuan. At the sometime,the debris flow endangered the Lianghong Station.This debris flow was aroused under hard rain. The rainfall was 55. 2mm/h. It was viscous debris flow. Its volume weight was up to 2. 18t/m3. In balance equation,Qc=QB(1 + (?))DC. Thereby,the maximum discharge of debris flow was 352. 1m3/s. The freeboard of bedris flow was 5-6m in bends of gully. The velocity of the first debris flow was about 8m/s. The maximum velocity may be 10-12m/s. Its duration was below 20 minutes and the solid materials were 80,000-90,000m3.