Study on blasting technology for protective layer of structures of the three gorges project

摘要

Protective layer excavation for structure foundation remains one of the difficult problems that puzzle construction of water resources and hydropower projects. In recent years some valuable tries and tests have been made in some of hydroelectric projects in China. However these tries are always on the way of experimentation, so far in no any job-site has been used the single-shot blasting method in the excavation of the protective layer above structure foundation requirements. On the base of successful tests, Gezhouba Group Corporation carried out large-scale single-shot blasting and mucking -out for the protective layer of longitudinal concrete cofferdam as permanent structure in the right bank, with surfce of shot bedrock of over 15000m~2. That offer us expeiences that we can make use of in the future construction of large-scale blasting.