Analysis of vibration differences induced by different typical blast-holes and the inherent causes in excavation of hydropower dam foundation

被引：0

作者：

Zhou H. ^{[1
]}

Gao Q. ^{[1
,2
,3
]}

Wang Y. ^{[1
]}

Fan Y. ^{[2
]}

Lu W. ^{[3
]}

Leng Z. ^{[4
]}

机构：

[1] School of Highway, Chang’an University, Xi’an

[2] Hubei Key Laboratory of Construction and Management in Hydropower Engineering, China Three Corges University, Yichang

[3] Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering Ministry of Education, Wuhan University, Wuhan

[4] Cezhouba Croup Explosive Co.Ltd, Chongqing

来源：

Shuili Xuebao/Journal of Hydraulic Engineering | 2022年 / 53卷 / 09期

关键词：

blasting boundary; different kinds of blast-holes; hydropower dam foundation; rock blasting; vibra-tion differences;

D O I：

10.13243/j.cnki.slxb.20220160

中图分类号：

学科分类号：

摘要：

The study on the vibration characteristics induced by different kinds of blast-holes in hydropower dam foundation excavation is of significance for the safety control of blast vibration. Based on onsite blasting experi¬ments, the Peak Particle Velocity (PPV) and the Dominant Frequency (DF) of blast vibration induced by the production blast-holes, the presplitting blast-holes and smooth blast-holes were compared in dam foundation exca¬vation. Moreover, combining with the analysis of the blasting boundaries, the dynamic responses of rock mass were studied by using the numerical simulation software. Finally, the inherent causes of the differences of vibration induced by different kinds of blast-holes were discussed, from the views of the distribution of explosion energy and the development of plastic zone. The results indicate that when the maximum charge of each shot and the distance between the explosive center are at the same level, the PPV and the DF induced by presplitting blast-holes are rel¬atively larger than those induced by production blast-holes and smooth blast-holes, while the PPV and DF induced by smooth blast-holes are approximate to the production blast-holes. The presplitting blast-holes are always the first fired blast-row. Their burden width is thus bigger than that of production blast-holes and smooth blast-holes. Moreover, the explosives charging in the presplitting blast-holes are generally radially and axially decoupled with the rock mass, so they are laterally initiated by the detonating cord. As a result, the blast-induced damage zone and the plastic zone is relative smaller. Therefore, less energy is consumed by rock fragmentation and more explo¬sive energy is transmitted into vibration energy. The smooth blast-holes have the similar charging structure and ini¬tiation mode with presplitting blast-holes, but the burden width of smooth blast-holes is smaller. Consequently, the blast-induced plastic zone and transmitted vibration energy of smooth blast-holes are similar with that of pro¬duction blast-holes. The blasting boundary (i.e., charging structure, initiation mode and burden size etc.) plays an important role on the distribution of plastic zone and explosion energy, which is the inherent cause of the differ¬ences of vibration characteristics. © 2022 China Water Power Press. All rights reserved.

引用

页码：1092 / 1104

页数：12

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