US 11,988,494 B2
Piston-type explosive loading and blasting structure and method for hard rock cable pit
Xin Zhang, Tianjin (CN); Jinshan Sun, Tianjin (CN); and Xiangping Zhang, Tianjin (CN)
Assigned to CHINA RAILWAY 18 BUREAU GROUP CO. LTD., Tianjian (CN)
Filed by CHINA RAILWAY 18 BUREAU GROUP CO. LTD., Tianjin (CN)
Filed on Sep. 28, 2022, as Appl. No. 17/954,766.
Claims priority of application No. 202211055419.8 (CN), filed on Aug. 31, 2022.
Prior Publication US 2024/0068790 A1, Feb. 29, 2024
Int. Cl. F42D 1/08 (2006.01); F42D 3/04 (2006.01)
CPC F42D 1/08 (2013.01) [F42D 3/04 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A piston-type explosive loading and blasting structure for a hard rock cable pit, comprising a first-step cut (1) provided at a center of an excavation section and second-step cuts (2) provided on a periphery of the first-step cut (1); wherein
piston-type explosive loading structures are used for explosives in the first-step cut (1) and the second-step cuts (2), and each piston-type explosive loading structure comprises a bottom cover (1-1), a middle cover (1-2), a top cover (1-3) and a fixing shaft (1-4); the bottom cover (1-1) is fixedly connected to the fixing shaft (1-4); the middle cover (1-2) and the top cover (1-3) sleeve the fixing shaft (1-4); in the first-step cut (1), an explosive loading region is formed between the bottom cover (1-1) and the middle cover (1-2); and a stemming sealing region is formed between the middle cover (1-2) and the top cover (1-3).