西藏某水电站厂区泥石流危险性分析与防治措施

西藏某水电站厂区后山发育了5条泥石流沟，2005年7月22日暴发了近百年来最大的泥石流，泥石流的规模和影响范围将直接影响到该厂房的枢纽布置、施工及运行安全。厂房区泥石流沟的泥石流固体物质来源丰富，形成区内沟道坡度陡峭，因此只要有足够的降雨就可以形成泥石流。以设计泥石流流量计算的泥石流的总径流量确定的泥石流危险范围与调查的厂区各条泥石流沟2005年的实际泛滥区很相近，并以此可以得到不同设计频率的泥石流危险区。电厂厂房区的设施在施工期和运行期间受到泥石流活动的一定影响，必须采取合理的泥石流工程防护措施，避免泥石流对厂房区设施的危害，保障电站的施工和运行，满足电厂厂区的建设需要。

ANALYSIS OF THE RISK AND PREVENTION METHOD ON THE SITE OF A HYDRAULIC POWER STATION IN TIBET, CHINA

There are 5 debris flows gullies in the area of a hydraulic power station in the Tibet. The debris flow occurred on July 22, 2005 is the largest one in 100 years. The scale and hazards range of debris flows could affect the key equipments, constructing and running of power station. As there is plenty of solid material in the debris flow gullies and the slopes of debris flow channels are very large, debris flows will be triggered by enough rainfall. The hazards range calculated by the volume of debris flows is close to the real inundating range of debris flows in 2005, so the hazards ranges of debris flows of different frequency were calculated by the volume of debris flows of the same frequency. As the key equipments, constructing and running of power station could be harm by debris flows, the prevention works must be taken to keep the hazards of debris flows away from the hydraulic power station