scholarly journals Seismic Analysis of Circular Elevated Water Tank Designed by Indian Standard and European Standard Code

2021 ◽  
Vol 9 (10) ◽  
pp. 1638-1641
Author(s):  
Siddhnath Verma
Keyword(s):  
Soft Soil ◽  
Soil Conditions ◽  
Water Tank ◽  
Base Shear ◽  
European Standard ◽  
Soil Medium ◽  
Seismic Zones ◽  
Standard Code ◽  
Hard Soil ◽  
Elevated Water

Abstract: Elevated water tank is used for storage of water which is used for distribution to the public at certain pressure head. In high seismic zones the safety of water tank becomes point of great concern which in case of failure becomes very hazardous for public because of deficiency of water for public use and difficulty in putting fire away caused by earthquake. The water tank must be designed as much strong so that it can perform during and after earthquake without failing. The aim of this study is to design the elevated water tank as per Indian standard code and European standard code on ETABS software. In this study an elevated circular water tank of 35 m3 capacity is being designed in seismic zone III as per IS code and spectrum zone II as per Euro code for hard soil, medium soil and soft soil conditions. During analysis of tank the values of base moment, base shear, storey displacement and storey drift is being obtained and compared in both seismic zones for hard soil, medium soil and soft soil. Keywords: base shear, base moment, ETABS, elevated water tank.

scholarly journals Seismic Analysis of Circular Water Tank Designed by Indian Standard Code and Euro Code

2021 ◽  
Vol 9 (10) ◽  
pp. 635-638
Author(s):  
Siddhnath Verma
Keyword(s):  
Seismic Analysis ◽  
Soft Soil ◽  
Soil Conditions ◽  
Water Tank ◽  
Base Shear ◽  
Seismic Behaviour ◽  
Soil Medium ◽  
Standard Code ◽  
Elevated Water ◽  
Water Tanks

Abstract: Water tanks are widely used for storage of drinking water. Water tanks and especially the elevated water tanks are structures of high importance which are considered as main lifeline elements that should be capable of keeping the expected performance i.e. operation during and after earthquakes. In this research paper, the analysis of the seismic behaviour of the elevated circular water tank by Indian standard code and Euro code is carried being carried out. The analysis is carried out on 35 cubic meter capacity elevated circular water tank in zone III and spectrum zone II and on three different soil conditions i.e. hard soil, medium soil and soft soil using ETABS software as per Indian standard code and European standard code. The results of base shear, base moment, storey displacement and storey drift are obtained from both codal provisions. Keywords: Elevated water tank, Seismic response, Etabs, Base shear, Base moment

Comparison between fixed base and isolated base in seismic response of high-rise buildings: a case study

2020 ◽  
Vol 6 (4) ◽  
pp. 204
Author(s):  
Anas M. Fares
Keyword(s):  
Response Spectrum ◽  
Soft Soil ◽  
Structural Response ◽  
Time History ◽  
Soil Condition ◽  
Soil Conditions ◽  
Spectral Acceleration ◽  
Base Shear ◽  
High Rise ◽  
Fixed Base

In this study, the influence of soil condition under the isolated and fixed bases is studied by using ETABS 16 software for the high-rise regular building. A regular building with 10 floors is modeled and the results are obtained for story displacements, story shear forces and spectral acceleration according to Uniform Building Code 97 (UBC-97) code. The time history analysis has been performed by using 1999 Izmit earthquake record. 3 types of soil which had different stiffnesses are considered in this study. The results show that the value of base shear increases when the soil stiffness decreases. It also noticed that the spectral acceleration is larger in soft soil condition than that of other soil conditions; and this confirms that the structural response spectrum is associated with the soil condition. In addition, when using base isolated building the drift of lower floors will be larger than that of using base isolated, but in the upper floors the drifts of fixed base building will be larger than that of the isolated base building. Finally, time history method in the seismic design will produce base shear less than that from equivalent static method, so calibration factor for design purpose shall be used.

scholarly journals Seismic performance of existing water tank after condition ranking using non-destructive testing

2019 ◽  
Vol 11 (4) ◽  
pp. 395-410 ◽  
Author(s):  
Chittaranjan B. Nayak ◽  
Sunil B. Thakare
Keyword(s):  
Seismic Vulnerability ◽  
Seismic Retrofit ◽  
Condition Index ◽  
Mode Shapes ◽  
Natural Phenomenon ◽  
Water Tank ◽  
Base Shear ◽  
Elevated Water ◽  
Non Destructive

Abstract There has been a collaborative attempt to address the seismic vulnerability of existing structures in India after an earthquake in Bhuj, Gujarat, in 2001. Seismic diagnosis and seismic retrofit for the existing tanks have become a remarkable issue to be worked since deterioration is a cosmopolitan and natural phenomenon. It is important to know the exact reason for distress and type of distress. To manage such issues, a proper method of repair and rehabilitation with detailed plans and methodology is required. This paper is aimed at evolving systematic investigation metrology for condition ranking procedure based on the analytical hierarchy process (AHP) and strengthening by various retrofitting strategies. For that case study, an existing elevated water tank is considered, which was designed according to state of the art over 40 years ago as per old Indian Standard (IS) code. The ranking assessment of the elevated service reservoir was carried out using different non-destructive tests (NDTs). DER, i.e., degree (D), extent (E) and relevancy (R) rating technique was employed to find out the condition index of the elevated service reservoir (ESR). After finding the condition ranking of the existing structure, an analysis was carried out using SAP 2000 to find the present-day seismic requirements using IS codes. After knowing the seismic demand of the water tank, various retrofitting methods were adopted for improving the drift capacity and flexural capacity of the structure. The results were finally used to address some of the critical issues of the seismic response of the retrofitted structure in terms of a time period, mode shapes, base shear, displacement, acceleration, and velocity. From the case study result of seismic retrofit for the existing elevated water tank, it is confirmed that a relatively simple seismic retrofit method is effective to keep the tank functional after an earthquake.

scholarly journals Strength Evaluation of Reinforced Concrete Structure for Regular Building due to Earthquake Load Based on Different Soil Types

2019 ◽  
Vol 5 (2) ◽  
pp. 123
Author(s):  
Jonie Tanijaya
Keyword(s):  
Reinforced Concrete ◽  
Response Spectrum ◽  
Soft Soil ◽  
Building Design ◽  
Soil Condition ◽  
Soil Types ◽  
Reinforced Concrete Structure ◽  
Base Shear ◽  
Negative Moment ◽  
Hard Soil

Earthquakes are natural events caused by tectonic plate movements and it is unpredictable. Thus, the building design regulation has an important role in ensuring the Earthquake resistant structure. A commonly used method is the response spectrum method. For different soil types, the value of the design spectra may increase or decrease. Therefore this study aims to determine the effect of soil type on the strength of reinforced concrete structures, especially the building behavior and structural internal forces. Analysis results show that the increase of base-shear value of Makassar is about 34% and 103% for medium soil and soft soil condition compared to hard soil. The increase of beam negative moment is about 27% to 39% in soft soil compared to hard soil, while the value is about 8% to 14% in medium soil compared to hard soil. The increase of beam positive moment varies considerably between 8% to 50%. The increasing moment is directly proportional to the required reinforcement area of the beam. Demand capacity ratio of column has also increased about 10% to 35% for medium soil and soft soil compared to hard soil.

scholarly journals Performance of elevated water tank staging with base isolation under blast loading

2021 ◽  
Vol 309 ◽  
pp. 01134
Author(s):  
Boda Balaraju ◽  
Atulkumar Manchalwar
Keyword(s):  
Base Isolation ◽  
Linear Time ◽  
Time History ◽  
Water Tank ◽  
Base Shear ◽  
Isolation Technique ◽  
Underground Blast ◽  
Base Isolator ◽  
Fixed Base ◽  
Elevated Water

In this present study aims to evaluate the performance of base isolation device under different intensity blast induced ground excitations for an elevated water tank staging. In this study mainly focused to improve the performance of the base isolator and minimize the damage of the structure. To know the performance of base isolator two models are considered one is fixed base model and another one is supported with base isolator model for both non-linear time history analysis is carried out with the help of SAP 2000 software subjected to four different underground blast intensities. From the analysis, it is observed that by using base isolator supported model structural responsive parameters such as base shear, top storey accelerations are efficiently reduced when compared to the fixed base structure. Hence it is proved that adopting base isolation technique we considerably reduce the damage of the structure subjected to underground blast vibrations.

scholarly journals Site characterizations of BMKG seismic network, Indonesia, based on HVSR analysis

2021 ◽  
Vol 873 (1) ◽  
pp. 012025
Author(s):  
Muzli Muzli ◽  
R A P Kambali ◽  
J Nugraha ◽  
S Sulastri ◽  
A R Hakim ◽  
...  
Keyword(s):  
Information Dissemination ◽  
Soft Soil ◽  
Spectral Ratio ◽  
Ratio Method ◽  
Waveform Data ◽  
Soil Medium ◽  
The Public ◽  
Seismic Waveform ◽  
Site Characteristics ◽  
Hard Soil

Abstract In the last few years BMKG (Agency for Meteorology Climatology and Geophysics) has increased the number of seismic stations significantly. Until mid-2020, when this study was conducted, the number of BMKG stations has reached 339 units. Development of the network is aimed to improve the data quality, speed of earthquake data processing and information dissemination to the public, accuracy of the hypocenter, as well as the magnitude. The objective of this study is to identify the site characteristics of the network. We analysed the noise recorded at BMKG stations throughout Indonesia using the HVSR (Horizontal to Vertical Spectral Ratio) method. The results of HVSR analysis were used to classify the site conditions of each station. We got the number of stations with the classification of hard rock, rock, hard soil, medium soil, and soft soil, 47, 57, 52, 30, and 84, respectively. This site condition represents the stations characteristics and affects the quality of seismic waveform data.

A Study on Mass Irregularity Limits of RC Structures for Various Seismic Zones of India

2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Mahammad Fayeemuddin ◽  
A. Vimala
Keyword(s):  
Aspect Ratio ◽  
Response Spectrum ◽  
Lateral Loads ◽  
Base Shear ◽  
Response Spectrum Analysis ◽  
Rc Structures ◽  
Seismic Zones ◽  
Regular Structures ◽  
Irregular Structures ◽  
Standard Code

The performance of any structure under lateral loads depends on its structural configuration. Most of the codes worldwide mentioned the provisions for the lateral load analysis for regular structures. Structures may be irregular in practice due to uneven distributions in mass, stiffness and strength. In India, most common type of multi-storied apartments constructed varies from 5 to 15 storeys and many apartments are constructed with penthouse which creates mass irregularity in the structures. The present study investigates the performance of mass irregular structures which are created by providing penthouse and also modeled as a stepped setback structure. Total four structures, 5, 7, 11 and 16 storied with an aspect ratio (height to width of the structure) of 0.64, 0.88, 1.36 and 1.96 are considered. For each structure response spectrum analysis is carried and the response parameters like storey displacements, storey drift and base shear variation in 4 seismic zones of India is studied. The main focus of the investigation is to understand the acceptance of mass irregularity with respect to the aspect ratio of the structure. The acceptance limit of the mass irregularity is also investigated as per 4 seismic zones of India. The results are compared with Indian standard code limits and concluded the acceptance limit as per seismic zones of India.

scholarly journals PERILAKU DINAMIK PELAT PERKERASAN KAKU AKIBAT BEBAN BERGERAK DENGAN KECEPATAN TIDAK KONSTAN

2020 ◽  
Vol 4 (1) ◽  
pp. 115
Author(s):  
Ridwan Halim ◽  
Sofia Alisjahbana
Keyword(s):  
Dynamic Load ◽  
Function Analysis ◽  
Concrete Slab ◽  
Soft Soil ◽  
Damping Ratio ◽  
Delta Function ◽  
Transverse Load ◽  
Soil Conditions ◽  
Soil Medium ◽  
Dirac Delta

Structural hard structures are often found in industrial buildings, especially in road structures. Most of the vehicles that pass on this road are heavy vehicles such as trucks with heavy loads. So, the engineer must design precisely so that this structure can meet the requirements of strength and deflection. The dynamic analysis of rigid pavement in this thesis is modeled as a concrete slab with boundary conditions all the edges of the slab have a semi rigid footing and on top of the soil media with a Pasternak foundation model that has elastic vertical spring support and a continuous sliding layer underneath. Transverse load that crosses the surface of the plate in the form of a dynamic load that has a initial speed and fixed acceleration. The load is modeled as a single axis centered load equivalent to variations in vehicle types such as: Colt Diesel Double (CDD) Los Bak, Colt Diesel Double (CDD) Long Box, and Colt Diesel Double (CDD) Body. In this study, various types of parameters will be analyzed, including the coefficient of the vehicle, the value of the damping ratio (damping ratio), and various supporting soil conditions, namely soft soil, medium soil and hard soil. Solving the plate dynamics problem with semi-rigid conditions using the Modified Bolotin Method (MBM) with the help of two transcendental equations. This dynamic load function solving uses the special properties of the Dirac-delta function. Analysis is carried out when the load is on the plate (0 ≤ t ≤ t0) with the final result obtained is the spectrum response or critical speed of the vehicle and the forces in the form of moments and shear forces. ABSTRAK Struktur perkerasaan kaku banyak dijumpai pada bangunan industrial khususnya pada struktur jalan. Sebagian besar kendaraan yang melintas pada jalan ini adalah kendaraan berat seperti truk dengan beban berat. Jadi, insinyur harus mendesain dengan tepat sehingga struktur ini dapat memenuhi syarat kekuatan maupun lendutan. Analisis dinamik perkerasan kaku dalam tesis ini dimodelkan sebagai pelat beton dengan kondisi batas semua tepi pelat memiliki tumpuan semi rigid dan di atas media tanah dengan model pondasi Pasternak yang memiliki dukungan pegas vertikal elastis dan lapisan geser menerus di bawahnya. Beban transversal yang melintasi permukaan pelat berupa beban dinamik yang memiliki kecepatan awal serta percepatan tetap. Beban dimodelkan sebagai beban terpusat sumbu tunggal ekuivalen dengan variasi jenis kendaraan seperti: Colt Diesel Double (CDD) Los Bak, Colt Diesel Double (CDD) Long Box, dan Colt Diesel Double (CDD) Bak. Dalam penelitian ini juga akan dilakukan analisis berbagai jenis parameter antara lain nilai koefisien kendaraan, nilai ratio redaman (damping ratio), dan berbagai kondisi tanah pendukung yaitu tanah lunak, tanah sedang, dan tanah keras. Penyelesaian masalah dinamika pelat dengan kondisi semi rigid menggunakan Modified Bolotin Method (MBM) dengan bantuan dua persamaan transendental. Pemecahan fungsi beban dinamik ini menggunakan bantuan sifat-sifat khusus fungsi Dirac-delta. Analisis dilakukan ketika beban berada di atas pelat (0 ≤ t ≤ t0) dengan hasil akhir yang didapat adalah respon spektrum atau kecepetan kritis kendaraan serta gaya-gaya dalam berupa momen dan gaya geser.

scholarly journals Checking the site categorization criteria and amplification factors of the 2021 draft of Eurocode 8 Part 1–1

2021 ◽  
Author(s):  
Roberto Paolucci ◽  
Mauro Aimar ◽  
Andrea Ciancimino ◽  
Marco Dotti ◽  
Sebastiano Foti ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Shear Wave ◽  
Ground Motion ◽  
Shear Wave Velocity ◽  
Soft Soil ◽  
Site Amplification ◽  
Soil Conditions ◽  
Eurocode 8 ◽  
Site Specific ◽  
Amplification Factors

AbstractIn this paper the site categorization criteria and the corresponding site amplification factors proposed in the 2021 draft of Part 1 of Eurocode 8 (2021-draft, CEN/TC250/SC8 Working Draft N1017) are first introduced and compared with the current version of Eurocode 8, as well as with site amplification factors from recent empirical ground motion prediction equations. Afterwards, these values are checked by two approaches. First, a wide dataset of strong motion records is built, where recording stations are classified according to 2021-draft, and the spectral amplifications are empirically estimated computing the site-to-site residuals from regional and global ground motion models for reference rock conditions. Second, a comprehensive parametric numerical study of one-dimensional (1D) site amplification is carried out, based on randomly generated shear-wave velocity profiles, classified according to the new criteria. A reasonably good agreement is found by both approaches. The most relevant discrepancies occur for the shallow soft soil conditions (soil category E) that, owing to the complex interaction of shear wave velocity, soil deposit thickness and frequency range of the excitation, show the largest scatter both in terms of records and of 1D numerical simulations. Furthermore, 1D numerical simulations for soft soil conditions tend to provide lower site amplification factors than 2021-draft, as well as lower than the corresponding site-to-site residuals from records, because of higher impact of non-linear (NL) site effects in the simulations. A site-specific study on NL effects at three KiK-net stations with a significantly large amount of high-intensity recorded ground motions gives support to the 2021-draft NL reduction factors, although the very limited number of recording stations allowing such analysis prevents deriving more general implications. In the presence of such controversial arguments, it is reasonable that a standard should adopt a prudent solution, with a limited reduction of the site amplification factors to account for NL soil response, while leaving the possibility to carry out site-specific estimations of such factors when sufficient information is available to model the ground strain dependency of local soil properties.

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