Deep-hole Blasting Techinical Research And Application For The Formation Of Bedrock And Weathering Boulder Of Taishan Nuclear Power Submarine Slurry Shield Tunnel

With the popularization and application of the shield technology incomposite formation, shield project facing more and more challenges of the complex geological conditions, especially the presence of the high-strength rock in the excavation section.In Granite formations of China’s southeastern coastal cities such as Qingdao, Fuzhou, Xiamen, Guangzhou, Shenzhen, Hong Kong and other places, it exist Globular Weathering body and invasived bedrock in tunnel excavation section to some extend. In this formation conditions, the shield tool can not effectively get rid of the high strength rock, traditional cabin opening or ground treatment methods tend to have greater limitations and the existing upper rock mass or weak strata around make it difficulty to artificial exploding. Therefore, the granite formations become one of the major source of risk for shield project.Relying on the submarine slurry shield tunnel project of Taishan nuclear power plant, based on the risk of the project, it proposed a pre-treatment of high strength rock in excavation section of the shield machine, its key technologies including two aspects:On the one hand, it first proposed a composite stratigraphy environment that the slurry shield tunnel in, taking the closed rock body and differences installments blasting into consideration, through stage blasting and the porous multi Millisecond Compression Blasting and eventually broken rock. On the other hand, Controlling lead explosive to the hole to avoid disturbing covering soil over boulders, to minimize the adverse impact on the surrounding environment and also ensure the superiority of the shield method. Finally, based on the test data of excavation and sampling test, using statistical regression analysis method to study the statistical relationship between the main factors and boring performance. Evaluating and analyzing bedrock and boulders deep hole blasting treatment effect by shield tunneling performance, cutter tool wear before and after blasting the core pulling detection.