Barrier holes and trench application to reduce blast induced vibration in Seyitomer coal mine     

Kaan Erarslan  Önder Uysal  Ercan Arpaz  M Akif Cebi 《Environmental Geology》2008,54(6):1325-1331

In this research, experimental applications have been performed to reduce blast induced vibrations in open pit mines. For this purpose, artificial discontinuity zones such as barrier holes and trench were opened in a dragline panel of Seyitomer Lignite Enterprise, Kutahya, Turkey. Peak particle velocities in front of and behind them were measured by seismographs. In this way, their effect against vibration was observed and compared. Barrier holes were opened 24 m deep through 3 parallel lines and aligned at 1 m spacing. On the other hand, the trench had 8 m depth and 4 m width. During the research, 209 measurements were taken belonging to 105 explosions. Twenty-eight explosions were carried out in the barrier holes experiments and 77 explosions were carried out in the trench experiments. A decrease in vibration of 14.3–18.5% was obtained behind the barrier holes while a decrease of 24.8–58.1% was provided by the trench.  相似文献   

基于修正πHW变分的板非协调动态有限元法     

王文广  孙建刚 《地震工程与工程振动》1998,18(1):54-59

本文本文讨论了基于修正πＨＷ变分的杂交应变板弯曲非协调动态有限元的分析列式,建立了四节点单元,进行了特征分析。算例表明,该单元是简单、有效的。  相似文献   

三峡船闸底扩与顶扩体型水力特性综合研究   总被引：4，自引：0，他引：4       下载免费PDF全文

胡亚安  张瑞凯 《水科学进展》1998,9(2):164-169

三峡船闸阀门段廊道体型一直是船闸单项技术设计的焦点。针对底扩与顶扩两种廊道体型,通过多项模型试验,从水力特性、空化及振动特性等方面论证了三峡船闸采用底扩廊道体型的优越性。  相似文献   

Multiple active–passive tuned mass dampers for structures under the ground acceleration     

Chunxiang Li 《地震工程与结构动力学》2003,32(6):949-964

An Erratum has been published for this article in Earthquake Engineering and Structural Dynamics 2003; 32(15):2451. Multiple active–passive tuned mass dampers (MAPTMD) consisting of many active–passive tuned mass dampers (APTMDs) with a uniform distribution of natural frequencies have been, for the first time here, proposed for attenuating undesirable oscillations of structures under the ground acceleration. The MAPTMD is manufactured by keeping the stiffness and damping coefficient constant and varying the mass. The control forces in the MAPTMD are generated through keeping the identical displacement and velocity feedback gain and varying the acceleration feedback gain. The structure is represented by the mode‐generalized system corresponding to the specific vibration mode that needs to be controlled. Through minimization of the minimum values of the maximum dynamic magnification factors (DMF) of the structure with the MAPTMD (i.e. through implementation of Min.Min.Max.DMF), the optimum parameters of the MAPTMD are investigated to delineate the influence of the important parameters such as mass ratio, total number, normalized acceleration feedback gain coefficient and system parameter ratio on the effectiveness (i.e. Min.Min.Max.DMF) and robustness of the MAPTMD. The optimum parameters of the MAPTMD include the optimum frequency spacing, average damping ratio and tuning frequency ratio. Additionally, for the sake of comparison, the results for a single APTMD are also taken into account in the present paper. It is demonstrated that the proposed MAPTMD can be employed to significantly reduce the oscillations of structures under the ground acceleration. Also, it is shown that the MAPTMD can render high robustness and has better effectiveness than a single APTMD. In particularly, if and when requiring a large active control force, MAPTMD is more promising for practical implementations on seismically excited structures with respect to a single APTMD. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

Application of non‐linear multiple tuned mass dampers to suppress man‐induced vibrations of a pedestrian bridge     

Nakhorn Poovarodom  Sopak Kanchanosot  Pennung Warnitchai 《地震工程与结构动力学》2003,32(7):1117-1131

This paper presents an application of multiple tuned mass dampers (MTMDs) with non‐linear damping devices to suppress man‐induced vibrations of a 34m long pedestrian bridge. The damping force generated by each of these damping devices is simply a drag force from liquid acting on an immersed section. The quadratic non‐linear property of these devices was directly determined from free vibration tests of a simple laboratory set‐up. Dynamic models of the bridge and pedestrian loads were constructed for numerical investigation based on field measurement data. The control effectiveness of non‐linear MTMDs was examined along with its sensitivity against estimation errors in the bridge's natural frequency and magnitude of pedestrian load. The numerical results indicated that the optimum non‐linear MTMD system was as effective and robust as its linear counterpart. Then, a six‐unit non‐linear MTMD system was designed, constructed, and installed on the bridge. Field measurements after the installation confirmed the effectiveness of non‐linear MTMDs, and the measurement results were in good agreement with numerical predictions. After the installation, the average damping ratio of the bridge was raised from 0.005 to 0.036 and the maximum bridge accelerations measured during walking tests were reduced from about 0.80–1.30 ms^?2 to 0.27–0.40 ms^?2, which were within an acceptable range. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

磁流变阻尼器的构造设计及其阻尼力性能的试验研究   总被引：21，自引：2，他引：21  

李忠献  吴林林  徐龙河  周云 《地震工程与工程振动》2003,23(1):128-132

本文根据磁流变液的材料特点和磁路设计原则，设计并制作了一个双出 杆的剪切阀式磁流阻尼器，在伺服试验机上对所设计制作的磁流变阻尼器的阻尼力性能进行了试验研究，并分析了影响阻尼力的各种因素。结果表明：所设计制作的磁流变阻尼器具有一定的剩磁，但剩磁对阻尼力可调系数的影响很小；所设计制作的磁流变阻尼器能够达到的最大阻尼力和阻尼力可调系数都很理想。由此得出结论，本文所设计制作的磁流变阻尼器具有卓越的阻尼性能，可在土木工程结构的半主动振动控制设计中加以推广和应用。  相似文献   

高层建筑利用TLD减小风振反应的研究   总被引：1，自引：0，他引：1  

贾影  赵林  李之富 《地震工程与工程振动》2003,23(1):160-165

本文利用调频液体阻尼器（TLD）对高层建筑风振响应进行了控制研究。通过理论计算与分析探讨了TLD中液体质量变化及TLD安装位置的不同对所研究的高层结构风振控制作用的影响，给出了合理的计算结果。  相似文献   

基岩地震动的一个相干函数模型--倾滑断层情形   总被引：6，自引：0，他引：6  

丁海平  刘启方  金星  袁一凡 《地震工程与工程振动》2003,23(2):8-11

本文研究了基岩随机地震动的空间变化规律，考虑了震源破裂速度、子源个数、震源深度和介质传播速度等因素的影响。对应于每个样本，用数值模拟方法计算了采用震源位错模型的弹性半空间近场地震动场，最后通过统计方法给出了一个倾滑断层情形下的近场基岩地震动的相干函数模型。这一方法可以补充常用的统计方法因观测资料有限而导致的欠缺。  相似文献   

强地震动数据采集系统研究   总被引：5，自引：2，他引：5  

高峰  陈先  魏继武 《地震工程与工程振动》2003,23(3):9-14

本文介绍了GDQJ—1A型强地震动数据采集系统的结构原理和技术性能，它可用于强地震观测和工程振动测量。  相似文献   

溢洪道高边坡控制爆破施工     

郝康群  周显贵 《地下水》2003,25(3):186-188

本文分析了单响药量和起爆网络对爆破振动的影响,结合控制爆破技术进行了振速监测,通过爆破监测估算出该地区爆破振动衰减规律,用以指导溢洪道开挖施工,保证了泄洪洞的安全。  相似文献