| The excavating method of protected level of foundation for hydraulic structure is directly concerned with the quality, progress and benefits of engineering. Advanced and reliable excavation method can not only greatly reduce the construction period and the costs for engineering , but also guarantee the safe operation of structure. However, the common excavating method can no longer meet the need of large scale construction in the hydropower engineering at present. Therefore, it is of paramount importance for engineering construction to study the One-Shot Explosion technology to accelerate the excavation of protected level.In this paper, several methods of OSE that setup an exemplify cushion on the hole bottom for excavating protected level are compared and analyzed, based on the engineering application and excavating experimentation for the past engineerings. The explosion mechanism, related facts, choice of parameters and condition of application are concretely studied, and the application of OSE for protected level in the excavation of dam foundation in the Three Gorges Project is presented, which provides valuable reference for the foundation excavation of other engineering. A new method of OSE, which setups a duplicate cushion (plus steel shroud) on the hole bottom to excavate the protected level of foundation rock is tried, which exemplifies a new way to study. |
