Seismic Response Analysis of Flexible Drain System Into External Floating Roof Storage Tanks

Author(s):  
Gary Bernard ◽  
Damien Vera ◽  
Weng Kheong Lim

Floating roofs are commonly used worldwide on top of cylindrical oil storage tanks as a primary means to prevent formation of vapor above stored products into the storage tanks and should provide a safe and efficient storage of products with minimal risk for the environment. However, aboveground storage reservoirs built in seismic zones are prone to earthquake damage. Extensive research has been done to enhance performance of the floating roof tanks against damage to ground foundations, fixed and floating roof, tank shells as well as adjacent piping. Indeed, the stored oil sloshing in a cylindrical storage tank is known to have caused damage to the tank shell, tank roof and as well to anti-rotation columns. One of the possible dangers of liquid sloshing is the resultant damage to in-situ roof drain systems within external floating roof tanks. Indeed, roof drain systems are designed for continuous withdrawal of rainwater from external floating roofs, and if damaged, would result in dysfunction of the systems and irreversible discharge of oil products into the containment dyke. In this regard, a reliable roof drain system should have the capability to withstand liquid sloshing effects, and to a certain degree, ensure resistance in events of displacement of the floating roof. The aim of this document is to use knowledge of flexible pipe technology and industry recognized dynamic analysis software to analyze the effects of earthquakes on the integrity of a flexible drain pipe system. Analysis of liquid sloshing effects on flexible drain pipe systems using dynamic analysis software will be presented and the effects of structural damages such as loss of anti-rotation columns on the integrity of flexible drain pipe systems will be assessed. In the end, the document will propose recommendations on how industry can further enhance roof drain systems within external floating roof tanks to ensure performance and functionality after occurrence of earthquakes.

Author(s):  
Shinsaku Zama

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.


Author(s):  
Philip J. Cacciatore ◽  
Benjamin F. Hantz ◽  
L. Magnus Gustafsson

Considerable interest has developed in the engineering community concerning the damage to the floating roof of oil storage tanks due to liquid sloshing from earthquake loading. Engineering groups in countries bordering the circum-Pacific seismic belt in particular are devoting extensive efforts to obtaining solutions capable of identifying vulnerable roof designs and developing modifications to improve strength. The recent efforts of the Japanese Fire Disaster and Management Authority (FDMA) as a result of 1995 Kobe and the 2003 Tokachi-Oki earthquakes are examples of recent work in this area. This paper focuses on efforts to analyze floating roof structures for stress and stability under typical earthquake velocity spectrums using advanced finite element methods. It employs ideas included in the Japanese FDMA studies, work done as part of the ASCE Committee on Gas and Liquid Fuel Lifelines, and some original methods developed at ExxonMobil. It has been applied to several tank designs and been submitted as a suitable advance analysis method to the Japanese FDMA. The paper provides both the theoretical foundation as well as an example covering typical tank geometry.


2004 ◽  
Vol 2004.6 (0) ◽  
pp. 21-22
Author(s):  
Shinsaku ZAMA ◽  
Minoru YAMADA ◽  
Haruki NISHI ◽  
Ken HATAYAMA ◽  
Masahiro HIROKAWA

Author(s):  
Yoshihiko Yamauchi ◽  
Asamichi Kamei ◽  
Sinsaku Zama ◽  
Yoshinori Uchida

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.


2011 ◽  
Vol 90-93 ◽  
pp. 1482-1485 ◽  
Author(s):  
Xu Dong Cheng ◽  
Jing Jing Hu ◽  
Li Ming Zhao

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.


2012 ◽  
Vol 487 ◽  
pp. 203-207
Author(s):  
Gong Xue Zhang ◽  
Xiao Kai Shen

Purpose, with the application of workbench finite element analysis software, get the analysis results of DVG 850 high-speed vertical machining center via the modal analysis and harmonic response analysis. Use the calculation results for reference, put forward the improved method, and prove the credibility of the simulation analysis by testing DVG 850 prototype.


1997 ◽  
Vol 15 (7-8) ◽  
pp. 755-764 ◽  
Author(s):  
S.A. Fazal ◽  
R. Rai ◽  
G.C. Joshi
Keyword(s):  

1987 ◽  
Vol 109 (1) ◽  
pp. 80-87 ◽  
Author(s):  
S. Takada ◽  
K. Tanabe

This paper presents a three-dimensional quasi-static analysis of continuous or jointed pipelines. Transfer Matrix Method was applied to the analysis providing for nonlinear behaviors of joints and soil frictions. An improved computer program ERAUL-II (Earthquake Response Analysis of Underground Lifelines-II) was developed for numerical computations. First, numerical response analyses were carried out for three-dimensional pipe systems with steel or cast iron pipe materials subject to large ground deformations or seismic ground motions. Analytical results show that torsional properties of pipes are also important factors for seismic behavior, which cannot be known by two-dimensional analyses. Second, experimental test data of three-dimensional steel pipe systems were simulated by using the ERAUL-II program. Simulated results agree well with the experimental values.


Sign in / Sign up

Export Citation Format

Share Document