金沙江其宗水电站上坝址深厚覆盖层钻进工艺探讨

Discussion on Drilling Process for Upper Damsite Deep Overburden Layer of Qizong Hydropower Station in Jinsha River

摘要:

其宗水电站属峡谷区修建的高坝、大库，最大坝高达358 m左右。深厚覆盖层的钻探取样是了解其成因及工程地质特性的必需手段，也是水电水利工程地质勘察工作的重要手段。由于覆盖层厚度大，组成物质分选性差，给钻探取心工作带来了困难。而取心质量直接关系到工程地质勘察资料的准确和详实。通过特殊钻具及SM植物胶钻井液的运用，提高了深厚覆盖层取心质量。结合其宗水电站的工程实例，对该地区深厚覆盖层钻进与取心工艺进行了探讨。

Abstract:

Qizong hydropower station is a high dam and large reservoir built in the canyon area. The maximum dam height was preliminarily planned to be about 358m. The drilling sampling of deep overburden layer is essential means to find out its cause and engineering geological property, and also the important means for water resources and hydropower engineering geological investigation. Because of the thick coverage layer with bad homogeneity of component substances, drilling coring is difficult. The coring quality is directly related to the accuracy and detail of engineering geological investigation data. By the application of special drilling tools and SM plant gum drilling fluid, coring quality in deep overburden layer was improved. The paper discusses the drilling and coring process in the deep overburden layer by the engineering case of Qizong hydropower station.