To investigate the influences of charge structures on the blast-induced ground vibration characteristics in hydraulic blasting, several onsite experiments were conducted in the context of Xinbin tunnel at the Shenyang to Jilin Expressway. Based on the onsite experiments, the peak particle velocity (PPV) and dominant frequency (DF) were analyzed under different kinds of charge structures, which includes the normal charge structure, the water bags located in the top of blasthole, the water bags located in the blasthole collar and the water bags located in the both ends of blasthole. In addition, the distribution laws of ground vibration under different charge structures were further studied using numerical simulation. The research results indicated that, compared with the normal charge structures, less explosive energy is converted into vibration energy in hydraulic blasting, resulting in smaller PPVs and higher DFs. Within 5 m of the cross section along the tunnel excavation face, the PPVs of blasting vibration under the normal charge structure exceed the vibration safety criteria, which is adverse for the safety control of ground structures. The converted vibration energy is relatively smaller along the direction of water bags in blasthole, but on the opposite direction of the blastholes more explosive energy is converted into vibration energy. In tunnel blasting excavation, the charge structure of the water bags located in the both ends of blasthole was recommended to promote the uniform distribution of vibration energy and minimize the disturbance to the surrounding structures.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |