Abstract:

The new composite anchorage structure indicates the ‘bolt-tectonic measure’ composite anchorage structure, it is applied to cavity reinforcement and support. ‘Tectonic measure’ indicates to construct a section of empty hole located at the end of inner bolt with processing the hole surface. This section of empty hole can weaken the medium, and it is named as ‘weakening hole’. The optimum design factors of the new composite anchorage structure include: ① weakening hole diameter, d; ② weakening density; ③ weakening length, l; ④ anchorage zone thickness, t. The optimum design of the above four factors is analyzed through numerical simulation with LS-DYNA code. The conclusions show that: optimum weakening hole diameter, 1.0; optimum design of weakening hole density is 24 weakening holes along cavity circle; optimum weakening hole length, 25 cm; optimum anchorage zone thickness, 25 cm (or the ratio of anchorage zone thickness to weakening hole length is 1).

Key words: anchorage structure, explosion, optimization, cavity