scholarly journals Dynamic Behavior of Elevated Water Tanks under Seismic Excitation

2020 ◽  
Vol 9 (9) ◽  
pp. 123-127
Keyword(s):  
Dynamic Behavior ◽  
Transient Analysis ◽  
Seismic Loading ◽  
Water Tank ◽  
Seismic Excitations ◽  
System Effect ◽  
Elevated Tanks ◽  
Elevated Water ◽  
Element Technique ◽  
Water Tanks

Elevated tanks are considered very sensitive to seismic excitations. That is why several researchers have studied the performance of these structures under seismic loading. The elevated tanks support‘s design are the most responsible reason of the damages and failures of this kind of structure . In this present paper, we are used the finite element technique to study the seismic response of them with taking into account the interaction between fluid and structure in the presence of sloshing. Modal and transient analysis are carried out on two types of the elevated tanks support, while keeping the same quantity of concrete and the same fluid volume. The displacements at the top of the tank and The fundamental period of the impulsive mode of the elevated water tank with shaft support decreased compared to the elevated water tank with frame support .The obtained results confirm the supporting system effect on dynamic behavior of elevated water tanks .

scholarly journals Parametric based study for design of liquid-filled elevated tanks

2016 ◽  
Vol 43 (7) ◽  
pp. 619-630 ◽  
Author(s):  
Mehdi Moslemi ◽  
Amir Reza Ghaemmaghami ◽  
M. Reza Kianoush
Keyword(s):  
Finite Element ◽  
Parametric Study ◽  
Three Dimensional ◽  
Time History ◽  
History Analysis ◽  
Wide Range ◽  
Elevated Tanks ◽  
Elevated Water ◽  
Element Technique ◽  
Water Tanks

In this study, the dynamic behavior of elevated water tanks is investigated by performing a comprehensive parametric study on conical elevated tanks using the finite element technique. Through this study, a wide range of tank parameters and geometries typically found in practice is considered. To perform this parametric study, a parametric model capable of building any finite element models of a three-dimensional conical elevated tank with varying parameters is developed. As a result of this parametric study, pressure distribution graphs corresponding to both impulsive and convective hydrodynamic pressures can be generated by carrying out spectral analysis. These pressure graphs can be utilized simply in design applications for liquid-filled conical elevated tanks. The accuracy of the proposed pressure graphs is verified by comparing these results with those calculated using the previously verified finite element time-history analysis and also the “current practice”.

scholarly journals Effect of Geometric Imperfection on the Dynamic of Elevated Water Tanks

2020 ◽  
Vol 6 (1) ◽  
pp. 85-97 ◽  
Author(s):  
Nasser Dine Hadj-Djelloul ◽  
M. Djermane
Keyword(s):  
Numerical Models ◽  
Time History ◽  
Dynamic Buckling ◽  
Three Dimensions ◽  
Nonlinear Time History Analysis ◽  
Water Tank ◽  
Geometric Imperfection ◽  
Elevated Water ◽  
Element Technique ◽  
Water Tanks

The elevated tanks are considered as very sensitive structures in seismic movement condition. Moreover, the conical steel tank manufacturing without local geometric imperfection seems to be too difficult. In generally, the latter is the most responsible factor to define the shell structures buckling capacity. For this reason, several theoretical and experimental researchers studied the performance of this type of structure under seismic loading.  The present study aims to demonstrate the local geometric imperfection effect on dynamic buckling of elevated water tank. Using the three dimensions finite element technique to study the seismic response of perfect and imperfect elevated water tank was established taking into account the following factors; the interaction fluid structure (FSI), the wall flexibility, the local geometric imperfection, the nonlinear time history analysis, the material and geometric nonlinearity, and this by the application of three different instability criteria for the critical PGA estimate. The critical PGA of the imperfect elevated water tank numerical models decreased by 45, 45% compared to the elevated water tank numerical model without local geometric imperfection. The obtained results confirm the local geometric imperfection effect on dynamic buckling of elevated water tanks.

scholarly journals Elevated Water Tank

2019 ◽  
Vol 8 (12S2) ◽  
pp. 271-276
Keyword(s):  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Water Tank ◽  
Elevated Water ◽  
Water Tanks ◽  
The Way

Water tanks are the capacity booths for putting away water. Raised water tanks are built to be able to deliver required head with the purpose that the water will movement affected by gravity the development exercise of water tanks is as antique as enlightened guy. The water tanks project has an firstrate want as it serves ingesting water for amazing populace from exceptional metropolitan urban groups to the little population dwelling in cities and towns. The smaller than ordinary project is led for a time of 15 days to have total all the way right down to earth information on unique tactics and issues appeared within the field. An change issue like construction factors, layout Parameters, information of Formwork, information of aid, process of Water treatment Plant and Execution had been controlled over the span of our smaller than regular undertaking."improved water tanks" via raising water tank, the enlargement upward push makes a conveyance strain at the tank outlet. The profile of water tanks begins offevolved with the utility parameters, consequently the type of materials applied and the form of water tank become directed by way of approach of those factors: 1. Vicinity of the water tank (inner, out of doors, over the floor or underground). 2. Volume of water tank need to preserve. 3. What the water may be utilized for? Four. Temperature of territory wherein might be located away, fear for solidifying. Five. Weight required conveying water. 6. How the water to be conveys to the water tank. 7. Wind and quake plan contemplations allow water tanks to endure seismic and excessive wind occasions

scholarly journals Innovative Experimentation on Hollow Cylindrical Shells of Reinforced Concrete under Axial Compressive Load

2019 ◽  
Vol 8 (3) ◽  
pp. 2044-2049
Keyword(s):  
Reinforced Concrete ◽  
Axial Compression ◽  
Structural Model ◽  
Testing Machine ◽  
Compressive Load ◽  
Water Tank ◽  
Critical Question ◽  
Axial Compressive Load ◽  
Elevated Water ◽  
Water Tanks

Reinforced concrete elevated water tanks supported on shaft type staging system are popularly constructed now a days for storage of water for water supply schemes. If slip form is used for casting of the shaft staging, the water towers generally require lesser time for construction. Elevated water tanks are top heavy structure especially in the tank full condition. It is often a critical question in structural design that what should be the proper structural model adopted for design of such class of structure. Should the shaft be designed as a hollow cylindrical column subjected to axial compression or is it essentially a R.C. cylindrical shell subjected to membrane forces under axial compression. To better understand it is proposed to cast such R.C. shells and after water curing for 28 days shall be subjected to axial compressive load in a compressive strength testing machine. The failure pattern of the shells shall be observed critically to get a proper understanding of behavior of such R.C shaft supported elevated water tank structures.

scholarly journals Fragility analysis of concrete elevated water tanks under seismic loads

2021 ◽  
Vol 15 (57) ◽  
pp. 93-113
Author(s):  
Hocine Hammoum ◽  
Amar Aliche ◽  
Karima Bouzelha ◽  
Younes Aoues ◽  
Ouali Amiri ◽  
...  
Keyword(s):  
Failure Modes ◽  
Fragility Curves ◽  
Probabilistic Approach ◽  
Seismic Loading ◽  
Soil Types ◽  
Structural Failure ◽  
Safety Factors ◽  
Partial Safety Factors ◽  
Elevated Water ◽  
Water Tanks

The design of concrete elevated water tanks involves several kinds of uncertainties. Traditionally, the design of these structures is based on a deterministic analysis. Partial safety factors prescribed in design codes are applied to take into account these uncertainties and to ensure sufficiently safe design. However, this approach does not allow rational evaluation of the risk related to the structural failure and consequently its reliability. In fact, the partial safety factors can lead to over-designed structures; or to under designed structural components leading to a lack of structural robustness. In this study, a probabilistic approach based on Monte Carlo simulations is used to analyze the reliability of elevated water tanks submitted to hazard seismic loading. This reliability approach, takes into account mainly two parameters. Firstly, the hydraulic charge in the tank container which is a function of time, and secondly, the hazard seismic loading through the Peak Ground Acceleration is considered as a random variable. Fragility curves depending on seismic zones and soil types are obtained by using the probabilistic approach, where they demonstrate the dominant failure modes that can cause the structural failure with respect to different seismic levels, soil types and water height level in the tank container.

scholarly journals Vibration Control of Water Tank Staging Equipped X-plate Damper

2019 ◽  
Vol 8 (4) ◽  
pp. 5551-5554
Keyword(s):  
Time History ◽  
Water Tank ◽  
Seismic Behaviour ◽  
Effective Technique ◽  
Linear Dynamic ◽  
Dissipation Of Energy ◽  
History Analysis ◽  
Steel Damper ◽  
Elevated Water ◽  
Water Tanks

During post-earthquake requirement the staging of elevated water tanks are considered as essential structures. Failure of staging leads to collapse of watertank so required to control the vibration of staging. In This paper elevated circular tank supported with frame was modeled to control the vibration of staging. Non-linear dynamic analysis (time-history analysis) was performed on model by using SAP2000 software to study the seismic behaviour. The additional dissipation of energy occurs by using damper constitute an effective technique for the earthquake reduction of staging members and In this study an attempt has been made to use the X-plate metallic steel damper for reducing the seismic response.

scholarly journals Investigation of applying dampers in elevated water tanks using time-history analysis

2015 ◽  
Vol 4 (1) ◽  
pp. 169
Author(s):  
Ehsan Rajaie
Keyword(s):  
Dynamic Behavior ◽  
Water Storage ◽  
Time History ◽  
Time History Analysis ◽  
Storage Tanks ◽  
Base Shear ◽  
Shear Forces ◽  
History Analysis ◽  
Elevated Water ◽  
Water Tanks

In this paper, the dynamic behavior of water storage tanks in investigated. Using time-history analysis based on three major earthquakes, the performance of system is illustrated. Two conditions, first with damper and second with no damper are presented and the relevant results are compared. The main results consist of base shear forces and also maximum target displacements. 

scholarly journals Use ofIn-SituDynamic Measurements to Calibrate Analytical Models of RC-Elevated Water Tanks

2012 ◽  
Vol 19 (5) ◽  
pp. 903-914
Author(s):  
H.M. Lopes ◽  
C.S. Oliveira
Keyword(s):  
Water Supply ◽  
Analytical Models ◽  
Ambient Vibration ◽  
Mode Shapes ◽  
Water Supply Systems ◽  
Water Tank ◽  
Analysis And Design ◽  
Elevated Water ◽  
Water Tanks

Before establishing the priority settings for the reduction of seismic risk of water supply infrastructures, it is necessary to understand the dynamic behavior of elevated water tanks, which are components of those infrastructures. Among other information, the main frequencies of vibration of these structures must be estimated and the analytical models used in their analysis and design should reproduce the frequency values obtained by in-situ dynamic tests. This work focuses exclusively on reinforced concrete (RC) elevated water tanks (200–750 m^3 of water at heights of 30–40 m), which are very common structures in the water supply systems in Portugal since the mid XXth century. This type of structures can also be seen in many regions around the world. First, a nationwide survey was conducted to determine the most common typologies in the country in terms of structural layout. Second, an in-situ campaign using ambient vibration as input was performed for a group of selected structures to determine the main frequencies of vibration and to identify modal shapes and damping values. Third, a finite element model of several different typologies was developed using the water simply as a concentrated mass at the top; the elastic properties of the model of the structure including the foundation were calibrated, so that the frequencies of various mode shapes obtained by the analytical model would match the frequencies of the real structure. Finally, an expression was derived to estimate the fundamental frequency of a group of elevated water tank typologies based on the total mass at the top of the supporting structure, which include the water, the global lateral stiffness, and the height of the tank. This study, providing important information on the frequencies of vibration of RC-elevated water tanks, contributes in a definite way to the analysis and design of such water tanks.

scholarly journals Analysis of Circular Elevated Service Reservoir Using STAAD Pro by Considering the Effect of Continuity

2021 ◽  
Vol 11 (4) ◽  
pp. 2603-2615
Author(s):  
Priyanka M. Mankar ◽  
H.R. Nikhade ◽  
Er. Minal Dehadrai ◽  
Khalid Ansari
Keyword(s):  
Seismic Analysis ◽  
Water Tank ◽  
Practical Application ◽  
Wind Analysis ◽  
The Common ◽  
Elevated Water ◽  
Water Tanks ◽  
Early Damage ◽  
Economical Losses ◽  
Continuity Analysis

In most regions of the country, early damage of elevated water tanks during their service life is becoming an increasing concern. The majority of damage occurs in tanks due to a lack of knowledge in design and ignoring continuity effect. Elevated water tank are used for storage of water at certain height and supplying water for essential usage. Hence damage of such structure endanger supply of drinking water and severe economical losses. The main purpose of this research is to determine the importance of continuity analysis in practical application and use of staadpro software to analyse an elevated circular water tank. The bottom joint of water tank is examined using continuity effect. This is the common joint where base slab, wall, bottom rings beam, gallery, column and base beam join. water tank is subjected to self-weight and hydrostatic Pressure due to water. Continuity effect increase stress, Hoop tension, BM hence its necessary to consider its effect while designing the tank. The results obtained from staadpro software is nearly same with manual result. This indicated that staadpro is suitable for design and analysis of water tanks. Three model having capacity of 55 m3, 125 m3 and 221 m3 situated in yavatmal, buldana and ramtek district is taken for analysis. Seismic analysis and wind analysis is also carried out on this model for safety purpose.

Non-Linear Time History Analysis of an Elevated Water Tank

2021 ◽  
Vol 9 (VI) ◽  
pp. 4327-4334
Author(s):  
Mr. Rohit Kiran Chaudhari
Keyword(s):  
Reinforced Concrete ◽  
Seismic Analysis ◽  
Linear Time ◽  
Time History ◽  
Seismic Energy ◽  
Soil Condition ◽  
Mode Shapes ◽  
Water Tank ◽  
Elevated Water ◽  
Water Tanks

It was discovered that reinforced concrete elevated water tanks with frame staging outperformed reinforced concrete elevated water tanks with shaft staging in terms of seismic resistance. These can be due to the frame staging's seismic energy absorption capability. As a result, the primary goal of this research is to better understand the seismic behavior and performance characteristics of elevated water tanks with frame staging. Furthermore, when compared to other shapes, circular tanks have the smallest surface area for a given tank size. As a result, the amount of material needed for a circular water tank is less than for other shapes. As a result, a circular water tank was chosen, and seismic analysis of elevated RC circular water tanks was carried out according to IITK-GSDMA guidelines, with the behavior of the water tank analysed for various parameters such as zone factor, soil condition, and different staging heights. SAP 2000 was used to determine the structure's modal characteristics (mode shapes and modal participation mass ratio).

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