Sloshing Response of Floating Roofed Liquid Storage Tanks Subjected to Earthquakes of Different Types

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
F. G. Golzar ◽  
R. Shabani ◽  
S. Tariverdilo ◽  
G. Rezazadeh
Keyword(s):  
Ground Motions ◽  
Far Field ◽  
Storage Tanks ◽  
Natural Period ◽  
Design Spectrum ◽  
Long Period ◽  
Lateral Forces ◽  
Different Types ◽  
Hamiltonian Variational Principle ◽  
Stress Patterns

Using extended Hamiltonian variational principle, the governing equations for sloshing response of floating roofed storage tanks are derived. The response of the floating roofed storage tanks is evaluated for different types of ground motions, including near-source and long-period far-field records. Besides comparing the response of the roofed and unroofed tanks, the effect of different ground motions on the wave elevation, lateral forces, and overturning moments induced on the tank is investigated. It is concluded that the dimensionless sloshing heights for the roofed tanks are solely a function of their first natural period. Also it is shown that while long-period far-field ground motions control the free board height, near-source records give higher values for lateral forces and overturning moments induced on the tank. This means that same design spectrum could not be used to evaluate the free board and lateral forces in the seismic design of storage tanks. Finally, two cases are studied to reveal the stress patterns caused by different earthquakes.

scholarly journals Seismic Energy Response of SDOF Systems Subjected to Long-Period Ground Motion Records

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Yu Cheng ◽  
Yao-Rong Dong ◽  
Li Qin ◽  
Yuan-Yuan Wang ◽  
Ye-Xue Li
Keyword(s):  
Ground Motions ◽  
Seismic Energy ◽  
Response Spectra ◽  
Design Parameters ◽  
Far Field ◽  
Input Energy ◽  
Energy Response ◽  
Hysteretic Energy ◽  
Near Fault ◽  
Long Period

To provide an important reference for the energy-based seismic design of long-period structures, the elastoplastic dynamic analysis program is employed to study the seismic energy response of single-degree-of-freedom (SDOF) systems under two types of typical long-period ground motions. Then, the influencing relationships of external and internal factors on the energy response spectra under near-fault pulse-like and far-field harmonic ground motions are analyzed one by one. Study results are obtained as follows: within the whole period, all the input energy, hysteretic energy and damping energy spectra of SDOF systems under near-fault pulse-like and far-field harmonic ground motions, are larger than those under common ground motions, even the seismic energy response under far-field harmonic ground motions is larger than that under near-fault pulse-like ground motions. From the aspect of energy concept, the energy response spectra and energy distribution rule of SDOF systems are evaluated based on the intensity and spectral distribution under near-fault pulse-like and far-field harmonic ground motions. If the ratio of hysteretic energy to input energy (RHEIE) is determined, the hysteretic energy which must be dissipated by a structure would be derived by the method of energy-based design. The input energy and hysteretic energy are mainly influenced by damping ratio and ductility coefficient, while the yield stiffness ratio exerts minor effects. It indicates that reasonable structural design parameters would contribute to the hysteretic energy of a structure itself.

scholarly journals Identification of Far-Field Long-Period Ground Motions Using Phase Derivatives

2019 ◽  
Vol 2019 ◽  
pp. 1-20
Author(s):  
Minghui Dai ◽  
Yingmin Li ◽  
Shuoyu Liu ◽  
Yinfeng Dong
Keyword(s):  
Response Spectrum ◽  
Ground Motions ◽  
Strong Motion ◽  
Sedimentary Basins ◽  
Corner Frequency ◽  
Training Dataset ◽  
Far Field ◽  
Long Period ◽  
Velocity Waveform ◽  
Attenuation Models

The characteristics of long-period ground motions are of significant concern to engineering communities largely due to resonance-induced responses of long-period structures to far-field long-period ground motions which are excited by the existence of distant sedimentary basins. Classifications of records enable applications of far-field long-period ground motions in seismology and engineering practices, such as attenuation models and dynamic analysis of structures. Accordingly, the study herein aims to develop an approach for identifying the far-field long-period ground motions in terms of the later-arriving long-period surface waves. Envelope delays derived from phase derivatives are employed to determine the later-arriving long-period components on the basis of phase dispersion. A quantitative calibration for long-period properties is defined in terms of the ratio of energy from later-arriving long-period components to the total energy of a ground motion. In order to increase the accuracy of candidate far-field long-period records caused by sediments, recording stations within basins or plains are collected from the K-NET and KiK-net strong-motion networks. Subsequently, the motions are manually classified into two categories in order to form a training dataset by visual examinations on their velocity waveform. The two predictive variables, including the corner frequency obtained from envelope delays and the corresponding energy ratio, are used for the establishment of the classification criterion. Furthermore, the analysis of classification results provides insight into the causes for discrepancy and verifies the effectiveness of the proposed method. Finally, comparisons of the mean normalized acceleration response spectrum with respect to the predictors, as well as the local site effects, are performed.

Sloshing Loads in Liquid-Storage Tanks with Insufficient Freeboard

2005 ◽  
Vol 21 (4) ◽  
pp. 1185-1192 ◽  
Author(s):  
Praveen K. Malhotra
Keyword(s):  
Storage Capacity ◽  
Ground Motions ◽  
Tank Wall ◽  
Storage Tanks ◽  
Simple Method ◽  
Long Period ◽  
Liquid Storage

Seismic ground motions excite long-period sloshing response in liquid-storage tanks. A minimum freeboard is needed to prevent the sloshing waves from impacting the roof of tanks. Since freeboard results in unused storage capacity, many tanks are not provided with the sufficient freeboard. As a result, sloshing waves impact the roof, generating additional forces on the roof and tank wall. This article presents a simple method of estimating these forces.

Liquid Sloshing of Oil Storage Tanks and Long-Period Strong Ground Motions in the 2003 Tokachi-Oki Earthquake

2004 ◽  
Author(s):  
Shinsaku Zama
Keyword(s):  
Seismic Waves ◽  
Ground Motions ◽  
Liquid Sloshing ◽  
Response Analysis ◽  
Storage Tanks ◽  
Severe Damage ◽  
Long Period ◽  
Oil Storage ◽  
Wave Heights ◽  
Strong Ground

The 2003 Tokachi-oki earthquake caused the severe damage to oil storage tanks by liquid sloshing. Especially at Tomakomai, two tank fires broke out and six floating roofs sank. Seismograms showed that long-period motions were predominant and duration became longer when the seismic waves propagated into the Yufutsu Plain, where Tomakomai is located. Sloshing wave heights (Wh) of all tanks were calculated by two-dimensional response analysis. It was found that estimated Wh exceeded 3 m at periods 5 and 7.5 sec, and exceeded 2m from 3.5 to 9 sec of sloshing period and that severe damaged tanks had the highest Wh at each period in general.

Seismic base shear coefficients of long-period structures subjected to far-field ground motions

2017 ◽  
Vol 34 (5) ◽  
pp. 488
Author(s):  
Minsheng Guan ◽  
Hongbiao Du ◽  
Qingli Zeng ◽  
Wei Cai ◽  
Jie Cui
Keyword(s):  
Ground Motions ◽  
Far Field ◽  
Base Shear ◽  
Long Period

Seismic Response Characteristics of Deep Soft Site with Depth under Far-Field Ground Motion of Great Earthquake

2011 ◽  
Vol 378-379 ◽  
pp. 477-483
Author(s):  
Ji Yan Zhan ◽  
Guo Xing Chen ◽  
Dan Dan Jin
Keyword(s):  
Peak Ground Acceleration ◽  
Response Spectrum ◽  
Ground Motions ◽  
Great Earthquake ◽  
Far Field ◽  
Acceleration Response ◽  
Ground Acceleration ◽  
Long Period ◽  
Reduction Coefficient ◽  
Acceleration Response Spectrum

Considering the dynamic nonlinear characteristics of soil by equivalent linear method, one-dimensional wave models were established to study the seismic effects along depth of deep soft sites under far-field ground motions of great earthquake. The results show that the magnified effect of acceleration response spectrum of each layer present more outstanding under far-field ground motions than under Suzhou artificial waves, with the increasing of bedrock peak ground acceleration, there is probability that the peak of long-period component of acceleration response spectrum appears higher than that of the short-period within 15m depth, which may adversely affect the long-period building structures. However, the reduction coefficient of peak ground acceleration (PGA) along depth according to the three levels of earthquake fortification standard was relatively higher when inputting far-field ground motions of great earthquake. As the curve fitted by Longjun Xu et al. based on records collected California Strong Motion Instrumentation Program geotechnical arrays of the United States and Hosokura Mine arrays of Japan, is not suitable for Suzhou area, suited quantitative formula about reduction coefficient curve of PGA with depth in deep soft site is given. Besides, maximum shear strain at the depth of approximately 15m and 40m present to be greatly changed when inputting far-field ground motions of great earthquake, with the growth of inputting bedrock peak ground acceleration, the layer in the depth of about 15m comes to be the most unfavorable position of shear deformation.

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