Abstract: Provided is a piston-type explosive loading and blasting structure for a hard rock cable pit. The structure includes a first-step cut provided at a center of an excavation section and second-step cuts provided on a periphery of the first-step cut; and piston-type explosive loading structures are used for explosives in the first-step cut and the second-step cuts. According to the piston-type explosive loading structures in the present disclosure, due to plastic plugging of stemming and fixed elastic plugging of two disc steel plates, time of energy such as stress waves and explosive gas generated after the explosives explode acting on surrounding rocks is obviously prolonged, rock mass is fully broken, and loose blasting is formed without throwing.

Abstract: The present invention relates to a reinforcement system at a railway tunnel section passing through a karst cave with a large dip angle and a construction method. The reinforcement system of the present invention can solve the problems of downward mud filling, watertightness, etc. of a top through structures of an umbrella arch, a concrete layer, a flexible buffer layer and a protective layer at the top, at a karst cave, of a tunnel, solve the problem of upward mud inrush at a bottom through structures of an anchor cable, a ring beam and a foundation pad at the bottom of the tunnel, guarantee stability of an arch bridge by erecting “a triple arch bridge” in a middle and adding a vertical bearing wall under the arch bridge, and make a railway safely cross the mud-inrush karst cave by safely laying a ballastless track on the bridge.

Abstract: Disclosed is a Bailey support system applied to cross protection of complex pipes and cables in an intersection tunnel, including a type I suspension system, a type II suspension system, type III suspension systems, a type IV suspension system, and a type V suspension system, where two groups of the type III suspension systems are disposed on a front side of the type IV suspension system, and two groups of the type III suspension systems are disposed on a rear side of the type IV suspension system and are in one-to-one correspondence with the other two groups disposed on the front side, the type II suspension system and the type I suspension system are sequentially disposed on a left side of the type IV suspension system from left to right, and the type V suspension system is disposed on a right side of the type IV suspension system.