The Formulations of Shear Force and Overturning Moment of the Large-Upright-Unanchored Industrial Liquid Storage Tanks Subjected to Horizontal Ground Excitations

2005 ◽  
Author(s):  
Mutlu Ozer
Keyword(s):  
Shear Force ◽  
Excitation Frequency ◽  
Response Analysis ◽  
Tank Wall ◽  
Storage Tanks ◽  
Base Shear ◽  
Ground Acceleration ◽  
Dynamic Coefficients ◽  
Liquid Storage ◽  
Overturning Moment

The dynamic response analysis is performed for the formulations of shear force and overturning moment of the large-upright-unanchored industrial liquid storage tanks subjected to horizontal ground acceleration. As the tank is accelerated in the horizontal direction, it tends to uplift from its foundation, and hydrodynamic pressures on the tank wall vary with height in non-linear fashion. In this study, the distribution of hydrodynamic pressures and its center are directly correlated to formulate shear force and overturning moment. Initially, the equations of shear force and overturning moment derived by assuming hydrodynamic pressures exerted on tank wall vary in parabolic trend. Then derived equations are multiplied by dynamic coefficients, which are basically the function of peak ground acceleration, excitation frequency and the ratio of liquid’s height to radius of tanks. Dynamic coefficients are formulated through the shake table experiment of the model tanks excited by computer generated ground motion. The equations proposed in this paper for base shear and overturning moment are only the function of total weight of tank, the ratio of liquid’s height to radius, specific weight of liquid and dynamic coefficients for shear force and overturning moment. Therefore, proposed equations are very simple, efficient and easy to perform in calculating of shear forces and overturning moments of the large-upright industrial liquid storage tanks subjected to lateral earthquake loads. The results are verified with different codes (e.g. Eurocode8, API and AWWA-100...).

Seismic design forces for cylindrical tanks on ground

1985 ◽  
Vol 12 (1) ◽  
pp. 12-23
Author(s):  
W. K. Tso ◽  
A. Ghobarah ◽  
S. K. Yee
Keyword(s):  
Radius Ratio ◽  
Hydrodynamic Effect ◽  
Tank Wall ◽  
Base Shear ◽  
Ground Acceleration ◽  
Liquid Storage ◽  
Wall Flexibility ◽  
Flexibility Effect ◽  
Predicted Values ◽  
Cylindrical Tanks

A study is made on the hydrodynamic effect caused by seismic ground motions on the design of cylindrical on-ground liquid-storage tanks. The current techniques for determining the design base shear and overturning moment of the tank are reviewed, first treating the tank wall as rigid and then including the wall flexibility effect. By means of examples, these calculations are compared with those suggested by the National Building Code of Canada (NBCC). In addition, theoretically predicted values are compared with experimental data.It was found that in the case of tanks of high height to radius ratio and small wall thickness to radius ratio, the interaction of the fluid and wall flexibility can cause responses as high as two to three times those calculated based on rigid tank wall assumptions. The range of tank geometries under which the tank can be considered rigid is given. It is shown that the NBCC formula to establish seismic loads for tanks on ground is in general conservative, provided the acceleration ratio in the NBCC formulae takes on the value of maximum peak ground acceleration of the site. Key words: seismic, earthquake, hydrodynamic force, response, cylindrical tanks, design code.

Applicability of Mass-Spring Models for Seismically Isolated Liquid Storage Tanks

2019 ◽  
Vol 13 (01) ◽  
pp. 1950002
Author(s):  
Afshin Kalantari ◽  
Mohammad Reza Nikoomanesh ◽  
Mohammad Ali Goudarzi
Keyword(s):  
Finite Element ◽  
Seismic Behavior ◽  
Element Model ◽  
Simplified Model ◽  
Design Parameters ◽  
Storage Tanks ◽  
Base Shear ◽  
Liquid Storage ◽  
Overturning Moment ◽  
Mass Spring

Employing base isolation technique for reduction of seismic response of liquid storage tanks has been proved to be quite effective. The main purpose of this paper is to quantitatively clarify, the contribution of convective and impulsive parts of the contained liquid in seismic behavior of an isolated liquid tank. Moreover, the accuracy of the simplified model which is generally used for the prediction of seismic behavior of conventional tanks is examined for isolated liquid tanks. For these purposes, the seismic response of the isolated cylindrical liquid storage tanks is considered using both the exact finite element model and simplified mass-spring model. The fluid–structure interaction is considered in finite element model. The comparison of the results obtained from two models shows that unlike conventionally constructed tanks, the contribution of convective mass cannot be neglected for seismically isolated tanks. Moreover, the accuracy of the simplified model for evaluating the main design parameters including base shear, global overturning moment, and sloshing height is examined for various tank dimensions and earthquake ground motions. The difference between the base shear and overturning moment results in the FE model and the simplified model of an isolated tank limited to 10%. It approves that the simplified mechanical models can be used with confidence for evaluating the seismic design parameters of various isolated tanks. However, the free surface displacement cannot be accurately predicted by simplified models, especially for medium and broad tanks.

Basic Theory of Simplified Dynamic Model for Spherical Tank Considering Swinging Effect

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Yuan Lü ◽  
Jiangang Sun ◽  
Zongguang Sun ◽  
Lifu Cui ◽  
Zhen Wang
Keyword(s):  
Dynamic Model ◽  
Shear Force ◽  
Velocity Potential ◽  
Fluid Pressure ◽  
Site Conditions ◽  
Base Shear ◽  
Site Condition ◽  
Spherical Tank ◽  
Overturning Moment ◽  
The Difference

Abstract Consider the swinging effect of spherical tank, the theory of velocity potential is adopted, and a reasonable potential function is derived according to the boundary conditions. Further, the dynamic fluid pressure, the wave height of the liquid, the shear force and the overturning moment at the bottom of the spherical tank is calculated, and a simplified dynamic model of spherical tank considering liquid sloshing and swinging effect was constructed. The seismic response was studied and compared with the results without considering the swing effect. The results show that: for Ι, II site conditions, base shear force and overturning moment of considering the swing effect is slightly smaller than when nonconsidering and the difference rate between the two is very small. III–IV site conditions, each condition value of considering the swing effect is larger than when nonconsidering and the difference rate between the two is relatively large. Aseismic design of spherical tank and the influence of swing effect should be considered if the site condition is III and IV, and if site I and II, they can be ignored.

Experimental Observations and Numerical Simulations of Wave Impact Forces on Recurved Parapets Mounted Above a Vertical Wall

2009 ◽  
Author(s):  
David Newborn ◽  
Nels Sultan ◽  
Pierre Beynet ◽  
Tim Maddux ◽  
Sungwon Shin ◽  
...  
Keyword(s):  
Numerical Model ◽  
Numerical Simulations ◽  
Shear Force ◽  
Experimental Testing ◽  
Vertical Wall ◽  
Experimental Tests ◽  
Vertical Force ◽  
Base Shear ◽  
Wave Impact ◽  
Overturning Moment

Large-scale hydraulic model tests and detail numerical model investigations were conducted on recurved wave deflecting structures to aid in the design of wave overtopping mitigation for vertical walls in shallow water. The incident wave and storm surge conditions were characteristic return period events for an offshore island on the North Slope of Alaska. During large storm events, despite depth-limited wave heights, a proposed vertical wall extension was susceptible to wave overtopping, which could potentially cause damage to equipment. Numeric calculations were conducted prior to the experimental tests and were used to establish the relative effectiveness of several recurved parapet concepts. The numerical simulations utilized the COrnell BReaking waves and Structures (COBRAS) fluid modeling program, which is a Volume-of-Fluid (VOF) model based on Reynolds Averaged Navier-Stokes equations [1] [2]. The experimental testing was conducted in the Large Wave Flume (LWF) at Oregon State University, O.H. Hinsdale Wave Research Laboratory. The experimental test directly measured the base shear force, vertical force, and overturning moment applied to the recurved parapets due to wave forcing. Wave impact pressure on the parapet and water particle velocities seaward of the wall were also measured. Results from the experimental testing include probability of exceedance curves for the base shear force, vertical force, and overturning moment for each storm condition. Qualitative comparisons between the experimental tests and the COBRAS simulations show that the numerical model provides realistic flow on and over the parapet.

The effects of input earthquake characteristics on the nonlinear dynamic behavior of FPS isolated liquid storage tanks

2016 ◽  
Vol 24 (7) ◽  
pp. 1264-1282 ◽  
Author(s):  
Saman Bagheri ◽  
Mostafa Farajian
Keyword(s):  
Passive Control ◽  
Base Isolation ◽  
Ground Motions ◽  
Storage Tanks ◽  
Ground Acceleration ◽  
Pendulum System ◽  
Aspect Ratios ◽  
Liquid Storage ◽  
Isolation Systems ◽  
Friction Pendulum

There are several methods to reduce the seismic damages in liquid storage tanks. One of these methods is to use passive control devices, in particular seismic base isolators. Among the different base isolation systems, the Friction Pendulum System (FPS) whose period does not depend on the weight of the system is more appropriate for isolation of liquid storage tanks. The aim of this paper is to investigate the effects of peak ground acceleration (PGA) and pulselike characteristics of earthquakes on the seismic behavior of steel liquid storage tanks base isolated by FPS bearings. In addition, impact effects of the slider with the side retainer are investigated, as well as effects of tank aspect ratio, isolation period and friction coefficient. The obtained results of tanks with different aspect ratios indicate that the responses get more reduced due to isolation under far-field ground motions compared to near-fault ground motions. It is also seen that the response of a base isolated tank is affected when contact takes place with the side retainer of the FPS.

Generalized SDOF system for dynamic analysis of concrete rectangular liquid storage tanks: effect of tank parameters on response

2010 ◽  
Vol 37 (2) ◽  
pp. 262-272 ◽  
Author(s):  
J. Z. Chen ◽  
M. R. Kianoush
Keyword(s):  
Dynamic Response ◽  
Natural Frequencies ◽  
Hydrodynamic Pressure ◽  
Characteristic Parameter ◽  
Added Mass ◽  
Tank Wall ◽  
Storage Tanks ◽  
Effective Height ◽  
Sdof System ◽  
Liquid Storage

This paper presents the results of parametric studies on the seismic response of concrete rectangular liquid storage tanks using the generalized single-degree-of-freedom (SDOF) system. The effects of height of liquid and width of tank on the dynamic response of liquid storage tanks are investigated. The liquid level varies from the empty condition to a full tank. Also, instead of the commonly used ratio of width of tank to liquid height, Lx/HL, the ratio of width of tank to full height of the tank wall, Lx/Hw, is used as a characteristic parameter of tanks to study the effect of tank size on the dynamic response. The trends of added mass of liquid, effective height, and natural frequencies for different sizes of tanks are established. The values of the added mass of liquid due to impulsive hydrodynamic pressure and the effective height in the relationship with the ratios Lx/Hw and HL/Hw are determined and can be used in the seismic design of liquid storage tanks. Since the natural frequencies of liquid-containing structures are within a band of frequencies between that of a full tank and that of an empty tank, the recommended frequency to be used in the design of the tank wall is the frequency that causes the maximum dynamic response .

scholarly journals Dynamic response of concrete rectangular liquid storage tanks

2021 ◽  
Author(s):  
Jun Zheng Chen
Keyword(s):  
Dynamic Response ◽  
Ground Motion ◽  
Added Mass ◽  
Tank Wall ◽  
Storage Tanks ◽  
Lumped Mass ◽  
Sequential Method ◽  
Mode Superposition Method ◽  
Liquid Storage ◽  
Vertical Ground

In this thesis, the dynamic response of concrete rectangular liquid storage tanks is investigated. In previous studies, the tank wall has been assumed as rigid in the calculation of hydrodynamic pressures. The effect of flexibility of tank wall is considered in this study. The analytical solutions for both impulsive pressure and convective pressure induced by both horizontal and vertical ground motions are presented. A 2-D coupled analysis model of tank wall is proposed. The hydrodynamic pressures are considered as external forces applied on the tank wall. Through a technique called the sequential method, the two fields of fluid and structure are coupled. The time-history analysis using the mode superposition method and the direct step-by-step integration method are carried out. Two rectangular tanks are analyzed. From the comparison of the results obtained from the proposed model with those proposed by other researchers, such as added mass model based on the rigid wall boundary condition, it shows that the lumped mass approach overestimates the base shear and wall displacement. The effect of wall flexibility on displacements, base shears and base moments are also discussed. A combination of the added mass method and the sequential method is used to study liquid storage tanks subjected to the vertical ground motion. It is found that the effect of the vertical acceleration should be considered in dynamic analysis of rectangular tanks. It is concluded that the total response of the structures should be based on the sum of the response under both horizontal and vertical components of ground motion.

scholarly journals Pembandingan Perancangan Bangunan Tahan Gempa Menggunakan SNI 1726:2012 Dan SNI 1726:2019

2021 ◽  
Vol 18 (1) ◽  
pp. 88-99
Author(s):  
Azis Wicaksana ◽  
Anis Rosyidah
Keyword(s):  
Shear Force ◽  
Seismic Analysis ◽  
Building Design ◽  
Response Analysis ◽  
Base Shear ◽  
Seismic Resistant ◽  
Story Drift ◽  
Moment Resisting ◽  
Special Moment Resisting Frame ◽  
Spectrum Response

Indonesia has a code for designing a seismic-resistant building, which has always improved year after year. Start from Peraturan Perencanaan Tahan Gempa Indonesia Untuk Gedung (PPTI-UG) 1983, SNI 1726:2002, SNI 1726:2012, and the latest one is SNI 1726:2019. SNI 1726:2019 experienced some renewal on designing a seismic-resistant building. This research aims to compare spectrum response design and the structural behavior between seismic-resistant building design using SNI 1726:2012 and SNI 1726:2019. The reviewed structure behaviors are base shear force (V), drift (δmax), and story drift (Δ). The study compares the detail of the structural components as well as using SNI 2847:2013 and SNI 2847:2019. The research uses a 10-story building modeling that serves as an apartment building and located in the city of Banda Aceh. Seismic analysis using a spectrum response analysis with Special Moment Resisting Frame (SMRF) structure. The result showed that the peak acceleration (Sa) for the class sites of Medium Land (SD) and Hard Land (SC) were 11% and 26%, respectively, while for Soft Land (SE), there was no increase. The shear force in SNI 1726: 2019 has increased by 19.75% for the X direction and 19.97% for the Y direction. The increase in the shear force is directly proportional to the increase in drift and story drift. In the beam detailing and beam-column connection, there were no significant changes. While in the column detailing, there are additional provisions that cause the transverse reinforcement to be tighter.

scholarly journals Dynamic response of concrete rectangular liquid storage tanks

2021 ◽  
Author(s):  
Jun Zheng Chen
Keyword(s):  
Dynamic Response ◽  
Ground Motion ◽  
Added Mass ◽  
Tank Wall ◽  
Storage Tanks ◽  
Lumped Mass ◽  
Sequential Method ◽  
Mode Superposition Method ◽  
Liquid Storage ◽  
Vertical Ground

In this thesis, the dynamic response of concrete rectangular liquid storage tanks is investigated. In previous studies, the tank wall has been assumed as rigid in the calculation of hydrodynamic pressures. The effect of flexibility of tank wall is considered in this study. The analytical solutions for both impulsive pressure and convective pressure induced by both horizontal and vertical ground motions are presented. A 2-D coupled analysis model of tank wall is proposed. The hydrodynamic pressures are considered as external forces applied on the tank wall. Through a technique called the sequential method, the two fields of fluid and structure are coupled. The time-history analysis using the mode superposition method and the direct step-by-step integration method are carried out. Two rectangular tanks are analyzed. From the comparison of the results obtained from the proposed model with those proposed by other researchers, such as added mass model based on the rigid wall boundary condition, it shows that the lumped mass approach overestimates the base shear and wall displacement. The effect of wall flexibility on displacements, base shears and base moments are also discussed. A combination of the added mass method and the sequential method is used to study liquid storage tanks subjected to the vertical ground motion. It is found that the effect of the vertical acceleration should be considered in dynamic analysis of rectangular tanks. It is concluded that the total response of the structures should be based on the sum of the response under both horizontal and vertical components of ground motion.

Seismic response analysis of adjacent liquid-storage tanks

2016 ◽  
Vol 45 (11) ◽  
pp. 1779-1796 ◽  
Author(s):  
Konstantinos Mykoniou ◽  
Christoph Butenweg ◽  
Britta Holtschoppen ◽  
Sven Klinkel
Keyword(s):  
Seismic Response ◽  
Response Analysis ◽  
Storage Tanks ◽  
Seismic Response Analysis ◽  
Liquid Storage
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