الفهرس 
Introduction to Storage Tank SystemsOnly 14 pages are availabe for public view
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Abstract
Large scale oil tanks are important devices for oil storage and are usually constructed in thecoastal areas or on the islands. Due to the poor soil conditions, the tanks are subjected todifferent types of settlement. Differential settlement is the main subject for this study, manyresearches were performed to study the effect of this type of settlement. The purpose of thisstudy is to find the effect of top stiffening ring on tank’s shape under differential settlementbeside, to find the effect of wall thickness variation on the behaviour of the tank.The study is composed of seven chapters, each of them dealing with different aspectsof the study. Chapter One is introductory about the tanks and its classification andcomponents.Chapter Two examines relevant researches in this field starting from the analytical solutionsand its achievements to the era of modern computer software where the researches deal withdifferent types of tanks and ending with the latest relevant researches in this topic especiallythe researches related to open top tanks and its results.Chapter Three illustrate method of analysis and the relevant subject such as: sources ofnonlinearity and its applications in life, the differences between linear and nonlinear analysisand quick review of the used analytical method.Chapter Four illustrates the approach and procedure used to verify the method of analysisthrough model verification. The geometric properties, material properties, loading andboundary conditions where mentions and the analysis results where compared to validate theprocedure.Chapter Five provides an outline for the study methodology. It’s is subdivided into two partswhile part one focus on the effect of wall thickness variation on buckling mode and verticalsettlement behaviour throw analysing 4 models with same geometric properties, part twoconcentrate on the effect of different top ring sections on two tanks one with constant wallthickness and the other one with varied wall thickness. In addition, the effect of top ring foreach case on vertical settlement, circumferential displacement and out of plan settlement weremention and compared for each top ring section.Chapter Six concentrates on problems results discussion and assessment from both parts. Acomparison between the behaviour of each ring in both tanks cases on the three types ofdisplacement, the range of ring effect was discussed, also a comparison between standardsrecommendations for differential vertical settlement and the calculated settlement based onthe analysis results were performed, finally economical assessment for the benefit from usingeach top ring section was performed based on the previous results.Conclusions are drawn in Chapter Seven. The main aim of the study is to clarify the effect oftop ring and range of its efficiency, besides this effect change regarding to the displacementtype but mainly the effect of top stiffening ring on all types of displacement are on a closerange. Based on the previous result and the standards recommendations it is recommended toreduce top ring section modulus by 50% from the required value which is mentioned in BSstandards.