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In order to successfully demolish two brick chimneys and two reinforced concrete chimneys located in the same plant area where is a complex environment by blasting. The overall blasting scheme of “single cut, directional collapse” is determined to demolish the four chimneys at one time, by analyzing the surrounding environmental conditions and the structural characteristics. According to the engineering experience, it is determined that the bottom edge of the chimney cut is at the elevation of+0.5 m, the cut angle is 215°, the cut height, cut length and relevant blasting parameters are calculated by theoretical formula. The cut form is trapezoid like, and the initiation network uses the digital electronic detonator initiation system with higher accuracy to initiate in the way of parallel firing. Considering the different structural composition of the four chimneys, corresponding pretreatment schemes are formulated respectively. Through the safety check of the collapse reliability, blasting vibration and collapse vibration of the chimneys and the effective control of the flying debris and flying stones after blasting, the four chimneys collapse in the design direction and prevent harm to the surrounding protection targets. By using the finite element software LS-DYNA to simulate the collapse process of four chimneys, the results show that the simulated collapse process is almost the same as the actual process, and the collapse completion time is around 14 s. Moreover, by analyzing the displacement and velocity law of the top node, it can be judged that the chimney collapse effect is sufficient and the expected goal is achieved, which further shows a guiding significance of the numerical simulation for engineering practice and can provide reference for similar projects.
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| 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 |
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