采用爆破方法处理沉井下沉刃脚处大漂石

在卵石层以及卵石层与风化花岗岩交界层中，沉井容易遇到大漂石搁置刃脚，从而出现下沉困难和偏斜问题。针对此问题，采取水下钻孔松动爆破技术及潜水员水下处理，清除刃脚底部漂石（最大颗粒漂石直径达到1.4m），从而使沉井下沉并有效控制纠偏，确保沉井均匀下沉至设计标高。

Case Study on Underwater Blasting of Boulders at Cutting Edge of Caisson

In pebble bed and transitional bed between weathered granite and pebble bed, caisson often meets boulders, which may hold the cutting edge. The problems of difficult sinking and inclination of caisson are presented. By underwater blasting technology for lossening rocks and divers’ treatments, the boulders at the cutting edge are cleared (the biggest boulder has the diameter of 1.4m), which ensures the sinking of the caisson to the desinged elevation with the required accuracy.