scholarly journals The sloshing law of liquid surface for ground rested circular RC tank under unidirectional horizontal seismic action

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lin Gao ◽  
Mingzhen Wang
Keyword(s):  
Seismic Response ◽  
Wave Height ◽  
Seismic Design ◽  
Liquid Surface ◽  
Damping Ratio ◽  
Liquid Sloshing ◽  
Seismic Action ◽  
Dynamic Coefficient ◽  
Established Method ◽  
Long Period

Abstract The dynamic characteristics and liquid sloshing of a circular tank are analysed using ADINA software through seismic response analyses. The maximum sloshing wave height for the circular tank under unidirectional horizontal seismic action is developed. The calculation method involves three parameters such as tank radius, seismic coefficient and dynamic coefficient. The dynamic coefficient of liquid sloshing is determined corresponding to the long-period seismic design β spectrum with a 5% damping ratio using basic sloshing period. The established method can guide the seismic design of liquid-containing structures. The established method of calculating sloshing wave height is compared with those in the American code.

Study on the Predictive Evaluation Method of Load Acting on the Roof and Internal Components of Cylindrical Tanks by Nonlinear Sloshing

2020 ◽  
Author(s):  
Hideyuki Morita ◽  
Tomoshige Takata ◽  
Hideki Madokoro ◽  
Hiromi Sago ◽  
Shinobu Yokoi ◽  
...  
Keyword(s):  
Wave Height ◽  
Seismic Isolation ◽  
Liquid Surface ◽  
Impact Load ◽  
Response Spectrum ◽  
Free Liquid Surface ◽  
Past Study ◽  
Long Period ◽  
Nonlinear Sloshing ◽  
Cylindrical Tanks

Abstract When cylindrical tanks installed in the ground, such as oil tanks and liquid storage tanks, receive strong seismic waves, including the long-period component, motion of the free liquid surface inside the tank called sloshing may occur. If high-amplitude sloshing occurs and the waves collide with the tank roof, it may lead to accidents such as damage of the tank roof or outflow of internal liquid of the Tank. Therefore, it is important to predict the wave height of sloshing generated by earthquake motions. Sloshing is a type of vibration of free liquid surface, and if the sloshing wave height is small, it can be approximated with a linear vibration model. In this case, the velocity-response-spectrum method using velocity potential can estimate the sloshing wave height under earthquake motions. However, if the sloshing wave height increases, the sloshing becomes nonlinear, and necessary to evaluate the wave height using other methods such as numerical analysis. Design earthquake magnitude levels in Japan tend to increase in recent years, long-period components of earthquake wave which act on the sloshing wave height also increase instead of introducing seismic isolation mechanisms. To evaluate load acting on the internal components of cylindrical tanks by nonlinear sloshing, there are few applications which quantitatively evaluated the crest impact load of nonlinear sloshing. In order to evaluate the load acting on the internal components of cylindrical tanks, the range of applicability of the fluid flow analysis method which validated the analysis accuracy of impact load acting on the roof in a simple cylindrical tank in the past study (PVP2019-93442) is extended to cylindrical tanks with internal components.

Study on the Predictive Evaluation Method of Nonlinear Sloshing Wave Height of Cylindrical Tanks: Part 2 — Proposal and Examination of Applicability of the Predictive Evaluation Method

2018 ◽  
Author(s):  
Hiromi Sago ◽  
Hideyuki Morita ◽  
Tomoshige Takata ◽  
Hideki Madokoro ◽  
Hisatomo Murakami ◽  
...  
Keyword(s):  
Wave Height ◽  
Seismic Isolation ◽  
Evaluation Method ◽  
Liquid Surface ◽  
Free Liquid Surface ◽  
Evaluation Technique ◽  
Long Period ◽  
Nonlinear Sloshing ◽  
Cylindrical Tanks ◽  
Simple Evaluation

When cylindrical tanks installed on the ground, such as oil tanks and liquid storage tanks, receive strong seismic waves, including the long-period component, motion of the free liquid surface inside the tank called sloshing may occur. If high-amplitude sloshing occurs and the waves collide with the tank roof, it may lead to accidents such as damage to the tank roof or outflow of internal liquid. Therefore, it is important to predict the wave height of sloshing generated by an earthquake input. Sloshing is vibration of the free liquid surface, and when the sloshing wave height is small, it can be approximated with a linear vibration model. In that case, the velocity-response-spectrum method using velocity potential can estimate the sloshing wave height under an earthquake input. However, when the sloshing wave height increases and the sloshing becomes nonlinear, it is necessary to evaluate the wave height using other methods such as numerical analysis. Taking into consideration that design earthquake levels tend to increase and the use of seismic isolation mechanisms has continued to spread in recent years, the amplitude of the long-period components of an earthquake input which act on cylindrical tanks may also increase. Therefore, although the evaluation of nonlinear sloshing wave height is important, there are few examples which quantitatively evaluate the wave height of nonlinear sloshing. The purpose of this study is to construct a simple evaluation technique of a nonlinear sloshing wave height of cylindrical tanks. In this study, the simple evaluation technique of the nonlinear sloshing wave height was proposed based on the study result shown by the 1st report (PVP2018-84416). Moreover, in order to verify the applicability of the proposed evaluation technique, the shaking table test and flow analysis which used the small cylindrical tank were carried out. As a result, the applicability of the proposed evaluation technique has been verified.

Fundamental Study on Evaluation Method of Nonlinear Sloshing Wave Height of Cylindrical Tanks

2017 ◽  
Author(s):  
Hideyuki Morita ◽  
Tomosige Takata ◽  
Hideki Madokoro ◽  
Hiromi Sago ◽  
Hisatomo Murakami ◽  
...  
Keyword(s):  
Wave Height ◽  
Liquid Surface ◽  
Flow Analysis ◽  
Vof Method ◽  
Free Liquid Surface ◽  
Evaluation Technique ◽  
Long Period ◽  
Nonlinear Sloshing ◽  
Cylindrical Tanks ◽  
Simple Evaluation

When cylindrical tanks installed in the ground, such as oil tanks and liquid storage tanks, receive strong seismic waves, including the long-period component, motion of the free liquid surface inside the tank called sloshing may occur. If high-amplitude sloshing occurs and the waves collide with the tank roof, it may lead to accidents such as damage to the tank roof or outflow of internal liquid. Therefore, it is important to predict the wave height of sloshing generated by an earthquake input. Sloshing is vibration of the free liquid surface, and when the sloshing wave height is small, it can be approximated with a linear vibration model. In that case, the velocity-response-spectrum method using velocity potential can estimate the sloshing wave height under an earthquake input. However, when the sloshing wave height increases and the sloshing becomes nonlinear, it is necessary to evaluate the wave height using other methods such as numerical analysis. Taking into consideration that design earthquake levels tend to increase and the use of seismic isolation mechanisms has continued to spread in recent years, it is possible that the long-period components of an earthquake input which act on cylindrical tanks will also increase. Therefore, although it is thought that the evaluation of nonlinear sloshing wave height is important, there are few examples which quantitatively evaluate the wave height of nonlinear sloshing. In this study, as a simple evaluation technique of a nonlinear sloshing wave height, the applicability of the correction coefficient proposed by Shimada et al. was examined based on the flow analysis which used Volume of Fluid (VOF) method. Moreover, it was studied that the VOF method can be used to evaluate nonlinear sloshing wave height and sloshing wave crest impact pressure acting on the fixed roof of a tank. Shaking table tests will continue to be carried out in order to verify the applicability of the simple evaluation technique of nonlinear sloshing wave height. Results from flow analysis code will also be validated against these test results.

Seismic Design of Floating Roof of Oil Storage Tanks Under Liquid Sloshing

2006 ◽  
Author(s):  
Yoshihiko Yamauchi ◽  
Asamichi Kamei ◽  
Sinsaku Zama ◽  
Yoshinori Uchida
Keyword(s):  
Wave Height ◽  
Seismic Design ◽  
Response Spectrum ◽  
Nonlinear Behavior ◽  
Liquid Sloshing ◽  
Storage Tanks ◽  
Natural Period ◽  
Oil Storage ◽  
Deck Plate ◽  
Sloshing Mode

The 2003 Tokachi-oki earthquake caused the severe damage to oil storage tanks by liquid sloshing. Especially at Tomakomai in Hokkaido, the ground motions at the periods of 3 to 8 sec predominated, which were harmonized with the natural period of liquid sloshing of oil storage tanks, then seven single-deck-type floating roofs were damaged and sank. For the 30,000kl FRT(φ 42.7m), one of those tanks, with about 7 see of fundamental sloshing period, maximum sloshing wave height was estimated 3m and over. On the other hand, for the 100,000kl FRT(φ 78.2m) with about 12 sec of fundamental sloshing period, maximum sloshing wave height was estimated about 1.5m and the excitation of 2nd sloshing mode was considered to be strongly excited. Considering both of nonlinear behavior of a large amplitude wave of 1st sloshing mode and nonlinear effects of large deflection of a deck plate at 2nd sloshing mode, we established the simplified method of seismic design of single-deck-type floating roofs using modified velocity response spectrum. This spectrum was based on many studies, investigated by Zama [1] and others, of the prediction of long-period strong ground motion and of liquid sloshing of oil tanks in Japan.

Study on the Predictive Evaluation Method of Nonlinear Sloshing Wave Crest Impact Load on the Roof of Cylindrical Tanks

2019 ◽  
Author(s):  
Hideyuki Morita ◽  
Tomoshige Takata ◽  
Hideki Madokoro ◽  
Hiromi Sago ◽  
Shinobu Yokoi ◽  
...  
Keyword(s):  
Wave Height ◽  
Seismic Isolation ◽  
Liquid Surface ◽  
Impact Load ◽  
Free Liquid Surface ◽  
Wave Crest ◽  
Long Period ◽  
Nonlinear Sloshing ◽  
Earthquake Motion ◽  
Cylindrical Tanks

Abstract When cylindrical tanks installed on the ground, such as oil tanks and liquid storage tanks, receive strong seismic waves, including the long-period component, motion of the free liquid surface inside the tank called sloshing may occur. If high-amplitude sloshing occurs and the waves collide with the tank roof, it may lead to accidents such as damage of the tank roof or outflow of internal liquid of the tank. Therefore, it is important to predict the wave height of sloshing generated by earthquake motion. Sloshing is a type of vibration of free liquid surface, and if the sloshing wave height is small, it can be approximated with a linear vibration model. In this case, the velocity-response-spectrum method using velocity potential can estimate the sloshing wave height under earthquake motion. However, if the sloshing wave height increases, the sloshing becomes nonlinear, and necessary to evaluate the wave height using other methods such as numerical analysis. Design earthquake magnitude levels in Japan tend to increase in recent years, long-period components of earthquake wave which act on the sloshing wave height also increase instead of introducing seismic isolation mechanisms. To evaluate sloshing wave crest impact load acting on the roof of a tank, there are few applications which quantitatively evaluated the crest impact load of nonlinear sloshing. To construct a simple technique to evaluate the sloshing impact load considering the nonlinear sloshing wave height which acts on a flat roof of cylindrical tanks, it is proposed that flow diagram of evaluating the sloshing impact load which newly took into consideration the nonlinearity of sloshing and the dynamic amplification factor. The applicability of the technique was verified with the shaking table tests results for cylindrical tank and flow-analysis results.

Dynamic Response Analysis of Vertical Cylindrical Storage Tanks Based on ADINA

2011 ◽  
Vol 90-93 ◽  
pp. 1482-1485 ◽  
Author(s):  
Xu Dong Cheng ◽  
Jing Jing Hu ◽  
Li Ming Zhao
Keyword(s):  
Seismic Response ◽  
Wave Height ◽  
Hydrodynamic Pressure ◽  
Liquid Sloshing ◽  
Response Analysis ◽  
Tank Wall ◽  
Storage Tanks ◽  
Peak Acceleration ◽  
Liquid Height ◽  
And Storage

Storage tanks after earthquake disaster may create the serious consequence, so their anti-seismic problems have drawn greater attention, and their seismic response become the focus of research. Considering the liquid-solid coupling and the interaction between foundation and storage tanks，three different volumes of storage tanks that have different liquid height were simulated under the earthquake using the software ADINA. The liquid sloshing wave height, peak acceleration of tank wall and hydrodynamic pressure were analyzed. The results show that the peak sloshing wave height shows a rising trend basically with the increase of liquid height, and the roofs of large tanks are more easier to be destroyed by liquid sloshing. With the increase of liquid height and tank volume, the response of peak acceleration is greater. The hydrodynamic pressure increases with the decrease of liquid height. Near the bottom of tank wall the value of hydrodynamic pressure is relatively large, so elephant foot buckling is easier to happen in that area.

Study on the Predictive Evaluation Method of Nonlinear Sloshing Wave Height of Cylindrical Tanks: Part 1 — Shaking Table Test Results and Verification Results of Analytical Method for Nonlinear Sloshing

2018 ◽  
Author(s):  
Hideyuki Morita ◽  
Tomoshige Takata ◽  
Hideki Madokoro ◽  
Hiromi Sago ◽  
Hisatomo Murakami ◽  
...  
Keyword(s):  
Wave Height ◽  
Shaking Table Test ◽  
Liquid Surface ◽  
Flow Analysis ◽  
Shaking Table ◽  
Test Results ◽  
Long Period ◽  
Nonlinear Sloshing ◽  
Analysis Technique ◽  
Cylindrical Tanks

When cylindrical tanks installed on the ground, such as oil tanks and liquid storage tanks, receive strong seismic waves, including the long-period component, motion of the free liquid surface inside the tank called sloshing may occur. If high-amplitude sloshing occurs and the waves collide with the tank roof, it may lead to accidents such as damage to the tank roof or outflow of internal liquid. Therefore, it is important to predict the wave height of sloshing generated by an earthquake input. Sloshing is vibration of the free liquid surface, and when the sloshing wave height is small, it can be approximated with a linear vibration model. In that case, the velocity-response-spectrum method using velocity potential can estimate the sloshing wave height under an earthquake input. However, when the sloshing wave height increases and the sloshing becomes nonlinear, it is necessary to evaluate the wave height using other methods such as numerical analysis. Taking into consideration that design earthquake levels tend to increase and the use of seismic isolation mechanisms has continued to spread in recent years, the amplitude of the long-period components of an earthquake input which act on cylindrical tanks may also increase. Therefore, although the evaluation of nonlinear sloshing wave height is important, there are few examples which quantitatively evaluate the wave height of nonlinear sloshing. The purpose of this study is to construct a simple evaluation technique of a nonlinear sloshing wave height of cylindrical tanks. In this study, the shaking table test using the small cylindrical tank for studying the behavior of nonlinear sloshing was carried out. Furthermore, verification of the flow-analysis technique described by previous report (PVP2017-65313) was carried out by comparing with test results. As a result, the data for constructing an evaluation technique has been acquired. Moreover, the validity of the flow-analysis technique was has been verified.

scholarly journals Probabilistic seismic response analysis of coastal highway bridges under scour and liquefaction conditions: does the hydrodynamic effect matter?

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Xiaowei Wang ◽  
Yutao Pang ◽  
Aijun Ye
Keyword(s):  
Seismic Response ◽  
Seismic Design ◽  
Highway Bridges ◽  
Element Model ◽  
Response Analysis ◽  
Hydrodynamic Effect ◽  
Strong Earthquakes ◽  
Influence Of Water ◽  
Scour Hazard ◽  
Ground Motion Records

AbstractCoastal highway bridges are usually supported by pile foundations that are submerged in water and embedded into saturated soils. Such sites have been reported susceptible to scour hazard and probably liquefied under strong earthquakes. Existing studies on seismic response analyses of such bridges often ignore the influence of water-induced hydrodynamic effect. This study assesses quantitative impacts of the hydrodynamic effect on seismic responses of coastal highway bridges under scour and liquefaction potential in a probabilistic manner. A coupled soil-bridge finite element model that represents typical coastal highway bridges is excited by two sets of ground motion records that represent two seismic design levels (i.e., low versus high in terms of 10%-50 years versus 2%-50 years). Modeled by the added mass method, the hydrodynamic effect on responses of bridge key components including the bearing deformation, column curvature, and pile curvature is systematically quantified for scenarios with and without liquefaction across different scour depths. It is found that the influence of hydrodynamic effect becomes more noticeable with the increase of scour depths. Nevertheless, it has minor influence on the bearing deformation and column curvature (i.e., percentage changes of the responses are within 5%), regardless of the liquefiable or nonliquefiable scenario under the low or high seismic design level. As for the pile curvature, the hydrodynamic effect under the low seismic design level may remarkably increase the response by as large as 15%–20%, whereas under the high seismic design level, it has ignorable influence on the pile curvature.

scholarly journals Near-Fault Seismic Response Analysis of Bridges Considering Girder Impact and Pier Size

Mathematics ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 704
Author(s):  
Wenjun An ◽  
Guquan Song ◽  
Shutong Chen
Keyword(s):  
Seismic Response ◽  
Bending Moment ◽  
Expansion Method ◽  
Response Analysis ◽  
Seismic Action ◽  
Transient Wave ◽  
Cross Sectional ◽  
Displacement Response ◽  
Near Fault ◽  
Continuous Girder Bridge

Given the influence of near-fault vertical seismic action, we established a girder-spring-damping-rod model of a double-span continuous girder bridge and used the transient wave function expansion method and indirect modal function method to calculate the seismic response of the bridge. We deduced the theoretical solution for the vertical and longitudinal contact force and displacement response of the bridge structure under the action of the near-fault vertical seismic excitation, and we analyzed the influence of the vertical separation of the bridge on the bending failure of the pier. Our results show that under the action of a near-fault vertical earthquake, pier-girder separation will significantly alter the bridge’s longitudinal displacement response, and that neglecting this separation may lead to the underestimation of the pier’s bending damage. Calculations of the bending moment at the bottom of the pier under different pier heights and cross-sectional diameters showed that the separation of the pier and the girder increases the bending moment at the pier’s base. Therefore, the reasonable design of the pier size and tensile support bearing in near-fault areas may help to reduce longitudinal damage to bridges.

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