水下爆破切割装置研究     

彭学伦 《海洋技术学报》2005,24(2):80-83

介绍一种水下爆破切割装置的组成、特点、工作原理及试验情况,并对水压引信、水下聚能定向爆破等关键技术进行了有益的探讨。  相似文献   

Comparative study of analytical and numerical evaluation of the dynamic response of buried pipelines to road-cut excavation blasting     

Amir Sajjad Abedi  Sina Shivaei  Arsalan Ghahramani 《Geomechanics and Geoengineering》2020,15(2):140-148

ABSTRACT

This study develops a mathematical model of buried pipelines subjected to surface blast loading based on the theory of beam on elastic foundation. The Fourier transform, a mathematical formula that converts the time domain of the problem to the frequency domain, was used in order to solve a fourth-order non-homogeneous partial differential equation. Transforming the solution back to the time domain, the blast-induced Peak Particle Velocity (PPV) of the pipeline can be calculated. In addition to the mathematical model, a three-dimensional finite element model has been established, thereby drawing a comparison between analytical and numerical results. It can be concluded that the analytically calculated PPV values are found to be higher than the corresponding numerical values. Lastly, the safe distance from the pipeline to blast source and the maximum allowable ANFO explosive weight for two types of rock have been presented in the form of graphs by imposing a limit of 50 mm/s for PPV. This comparative study has investigated the effect of road-cut excavation blasting on pipelines buried under only two types of rock mass. However, it can be used for different types of rock and explosives, mainly thanks to the comprehensiveness of the analytical solution.  相似文献   

海南区域地震与爆破震源参数特征     

彭利媚  孙三健  李冬雅  陈小敏  张华美  洪流 《地震地磁观测与研究》2017,38(5):22-28

收集2008年以来海南测震台网记录的M_L 2.5以上地震及爆破资料,利用Brune圆盘模型,计算得出震源参数,发现地震、爆破的震源参数特征为:地震的拐角频率绝大多数大于爆破;地震应力降大于1,爆破应力降小于1;地震震源尺度绝大多数小于爆破。对一个有感疑爆事件,利用其拐角频率、应力降、震源尺度等参数,判定该事件为天然地震,与前人研究结果一致。由此可见,利用震源参数在地震速报、日常分析中判定事件类型具有实际意义。  相似文献   

G7公路甘肃段爆破施工对土遗址震动影响的检测与分析          下载免费PDF全文

赵亮  王旭东  裴强强  何新社  郭青林  张功 《地震工程学报》2017,39(2):343-347,355

近年来土遗址受城市建设和交通施工损害的现象时有发生,对于这些人为因素对遗址的影响缺乏有效的检测与评估手段。本文基于G7高速公路的爆破振动观测,进行质点峰值加速度和峰值速度的衰减分析,开展爆破震动对附近明水军事要塞土遗址震动影响的研究。通过对竖向、水平向的振动加速度和速度的观测和数据分析,得出不同药量条件下,对应相同质点的震动峰值加速度衰减规律。提出了公路爆破附近土遗址震动控制范围和最大药量的施工建议,为爆破附近有土遗址的施工提供了数据支持,相应的结论和建议可以在同类土遗址保护中参考使用。  相似文献   

Earthquake‐induced loss assessment of steel frame buildings with special moment frames designed in highly seismic regions          下载免费PDF全文

Seong‐Hoon Hwang  Dimitrios G. Lignos 《地震工程与结构动力学》2017,46(13):2141-2162

This paper discusses an analytical study that quantifies the expected earthquake‐induced losses in typical office steel frame buildings designed with perimeter special moment frames in highly seismic regions. It is shown that for seismic events associated with low probabilities of occurrence, losses due to demolition and collapse may be significantly overestimated when the expected loss computations are based on analytical models that ignore the composite beam effects and the interior gravity framing system of a steel frame building. For frequently occurring seismic events building losses are dominated by non‐structural content repairs. In this case, the choice of the analytical model representation of the steel frame building becomes less important. Losses due to demolition and collapse in steel frame buildings with special moment frames designed with strong‐column/weak‐beam ratio larger than 2.0 are reduced by a factor of two compared with those in the same frames designed with a strong‐column/weak‐beam ratio larger than 1.0 as recommended in ANSI/AISC‐341‐10. The expected annual losses (EALs) of steel frame buildings with SMFs vary from 0.38% to 0.74% over the building life expectancy. The EALs are dominated by repairs of acceleration‐sensitive non‐structural content followed by repairs of drift‐sensitive non‐structural components. It is found that the effect of strong‐column/weak‐beam ratio on EALs is negligible. This is not the case when the present value of life‐cycle costs is selected as a loss‐metric. It is advisable to employ a combination of loss‐metrics to assess the earthquake‐induced losses in steel frame buildings with special moment frames depending on the seismic performance level of interest. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

Proposed methodology for building-specific earthquake loss assessment including column residual axial shortening     

Ahmed Elkady  Gerard Güell  Dimitrios G. Lignos 《地震工程与结构动力学》2020,49(4):339-355

This paper proposes methodological developments for quantifying the impact of residual axial shortening of first-story steel columns on earthquake loss estimations in steel moment-resisting frame (MRF) buildings. A new formulation is proposed that accounts for the likelihood of having to demolish a steel MRF building due to column residual axial deformations in addition to residual story-drift ratios. The formulation is informed by means of data from a comprehensive survey conducted worldwide to assess the likelihood of steel column repairability due to residual axial shortening. A practical method for quantifying column axial-shortening in parameterized system-level numerical simulations is presented. The proposed approach is illustrated by conducting economic seismic loss estimations in two case-study steel MRF buildings designed in urban California according to the current seismic design practice. It is found that when the ground-motion duration is appreciable, the examined steel MRFs are more prone to column axial-shortening than residual story-drifts at moderate to high seismic intensities. The results suggest that economic losses due to demolition may be underestimated if column residual axial-shortening is neglected from loss estimations. Limitations as well as directions for future research are discussed.  相似文献   

Finite element analysis for blasting law of jointed rock mass     

YU Qingyang  NIE Lei  ZHOU Nengjuan College of Construction Engineering  Jilin University  Changchun  China 《东北亚地学研究》2009,(4):210-214

On the basis of Mises strength theory, rock models are built including vertical, horizontal and diagonal joints to simulate jointed rock mass under blasting load by using FEM. The dynamic procedures of jointed rock mass under blasting are quantified and the effective stress-time curves of typical elements are compared to analyze the barrier of joints to the stress wave. The blasting law was studied according to the process of computer simulation and the effect of blasting, and some suggestions were given for solving the problems of overbreak and underbreak.  相似文献   

冲击回转在复杂条件下钻进若干问题分析及处理措施   总被引：2，自引：0，他引：2  

熊青山  赵文玉 《地质与勘探》1999,35(4):56-58

气动冲击回转钻进主要应用于难用或忌用液体作为循环介质的地区。而“引松入长”工程中的爆破孔施工是在水量极丰富、气温极低、地层极复杂条件下进行,本文对其出现的问题进行了分析,并提出了合理的解决措施  相似文献   

裂隙,岩溶含水层疏排水钻孔的爆炸洗孔试验研究     

严家平  颜事龙 《水文地质工程地质》1999,26(5):53-54

在裂隙,岩溶裂隙含水层水文地质条件研究基础上,根据炸药在水中原理,介绍了控制炸药爆炸能量和孔内爆炸方法,达到对岩体的爆炸致裂以及对原储导水裂隙的冲刷作用,提高了地下工程中钻孔或水源井的疏排效率,同时又保护站孔孔壁不被破坏。  相似文献   

水介质爆破拆除地下桩体的实践   总被引：1，自引：0，他引：1       下载免费PDF全文

白聚波 《探矿工程》1999,(4):54-55

介绍了地下钢筋混凝土桩的控制爆破方法,以及在钻孔设备及外界约束较特殊的情况下,钻孔、装药及起爆等方面的注意事项。  相似文献