三峡库区特殊地质3.0m直径深水桩基冲孔技术

Techniques for Construction of Deep Water Piles of 3.0 m in Diameter in Special Geological Conditions in Three Gorges Reservoir Area

石忠高速公路忠县长江大桥南主塔墩基础为准3.0 m直径的19根群桩,采用冲击钻成孔施工工艺,受三峡三期蓄水影响,要求该墩桩基在4个月内完成。文章针对三峡库区特殊地质和施工环境,重点介绍了冲击钻成孔工艺的钻机设备选型、泥浆指标及除渣清孔方法、冲孔工艺工法、特殊问题处理措施等,并结合施工工效和施工实际总结分析,证明设计工艺和预案能满足本项目施工需要。

Zhongxian Bridge over the Changjiang River is located on the Shi-Zhong Expressway and the footing of the southern main tower is made of 19 piles of 3.0 m diameters in diameter, which were installed with the construction technology of percussion drilling. Affected by the water storage of the third-stage in the Three Gorges Reservoir, the group-pile foundation was requested to complete in 4 months. In view of the special geological conditions and the construction conditions in the Three Gorges Reservoir, the paper mainly introduces the selection of drilling equipment, slurry properties, method of debris removal and hole cleaning, drilling procedure and measures to deal with special difficulties and analyzes the construction efficiency and construction practice, which proves that the design technology and the counter-plan can meet the construction requirements.