Seismic response reduction for tall buildings by suspended mass pendulums (in Chinese)

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Piotr Adam Bońkowski ◽  
Juliusz Kuś ◽  
Zbigniew Zembaty

AbstractRecent research in engineering seismology demonstrated that in addition to three translational seismic excitations along x, y and z axes, one should also consider rotational components about these axes when calculating design seismic loads for structures. The objective of this paper is to present the results of a seismic response numerical analysis of a mine tower (also called in the literature a headframe or a pit frame). These structures are used in deep mining on the ground surface to hoist output (e.g. copper ore or coal). The mine towers belong to the tall, slender structures, for which rocking excitations may be important. In the numerical example, a typical steel headframe 64 m high is analysed under two records of simultaneous rocking and horizontal seismic action of an induced mine shock and a natural earthquake. As a result, a complicated interaction of rocking seismic effects with horizontal excitations is observed. The contribution of the rocking component may sometimes reduce the overall seismic response, but in most cases, it substantially increases the seismic response of the analysed headframe. It is concluded that in the analysed case of the 64 m mining tower, the seismic response, including the rocking ground motion effects, may increase up to 31% (for natural earthquake ground motion) or even up to 135% (for mining-induced, rockburst seismic effects). This means that not only in the case of the design of very tall buildings or industrial chimneys but also for specific yet very common structures like mine towers, including the rotational seismic effects may play an important role.


Author(s):  
Ahmad Sheikh Abdallah ◽  
Safwan Chahal

The rapid growth of urban population and limited land space have greatly influenced the development of high-rise structures. Lateral loads have an important effect on the design as the building height increases. In order to resist lateral loads, safety and minimum damage should be the prime concern when designing tall buildings. To meet these requirements, the structure should have adequate lateral strength and lateral stiffness and sufficient ductility. Among the various structural systems, shear wall systems or moment resisting frame systems could be a point of choice for designers. Thus, it is important to review and observe the behavior of these systems under seismic effect. This study compared the seismic response of the above structural systems using a case study application at variable seismic zones (Zone 2B, Lebanon Zone, Zone 3, and Zone 4) and at different building stories (Eight and 12-story building). The seismic response is measured in term of time-period, maximum story displacement, maximum story drift, amount of steel and concrete needed. The outcome of this study portrayed that a shear wall system is more efficient in terms of cost and lateral load resistivity regardless of the building height and in the four seismic zones mentioned before.


2003 ◽  
Vol 10 (4) ◽  
pp. 88-94
Author(s):  
Xu Youlin ◽  
Chen Jing ◽  
NG Chi Lan ◽  
Qu Weilian

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