Seismic Vulnerability Assessment of Multistory Timber Braced Frame Traditional Masonry Structures

2012 ◽  
Vol 601 ◽  
pp. 168-172 ◽  
Author(s):  
Naveed Ahmad ◽  
Qaisar Ali ◽  
Muhammad Umar
Keyword(s):  
Dynamic Analysis ◽  
Seismic Vulnerability ◽  
Seismic Analysis ◽  
Pushover Analysis ◽  
Elastic Beam ◽  
Lateral Force ◽  
Experimental Results ◽  
Constitutive Law ◽  
Masonry Structures ◽  
Braced Frame

Research carried out on the seismic investigation of timber braced frame (TBF) masonry structures of traditional construction practice is presented, essential for seismic performance evaluation of such construction type using engineering approaches. An innovative simplified equivalent frame method (EFM) based on macro modelling approach is presented for nonlinear dynamic seismic analysis of TBF masonry structures. The modelling include EFM idealization of wall using stiff elastic beam-column element assigned with moment-rotation (M-θ) nonlinear lumped plasticity hinges. Earlier, the approach i.e. the EFM idealization and M-θ constitutive law, is calibrated with the experimental results obtained through quasi-static cyclic test on full scale walls. The technique is further extended herein for seismic dynamic analysis of multistory structures. Generalization of the technique for modelling walls of various geometry and loading is performed. It included nonlinear static pushover analysis of various case study walls, by means of SAP2000 calibrated earlier with experimental results, for the derivation of lateral force-deformability behavior towards the development of generalized M-θ constitutive law for TBF masonry walls. Three representative structures, from one to three storeys, are analyzed using a suite of ten natural accelerograms and incremental dynamic analysis technique. Structure fragility and resilience functions are derived using a fully probabilistic and dynamic approach. The structures analyzed in the present study represent TBF masonry wall structures, called as Dhajji-Dewari structures, common in Northern areas of Pakistan.

scholarly journals Seismic vulnerability of the Himalayan half-dressed rubble stone masonry structures, experimental and analytical studies

2012 ◽  
Vol 12 (11) ◽  
pp. 3441-3454 ◽  
Author(s):  
N. Ahmad ◽  
Q. Ali ◽  
M. Ashraf ◽  
B. Alam ◽  
A. Naeem
Keyword(s):  
Experimental Study ◽  
Seismic Vulnerability ◽  
Structural Model ◽  
Dynamic Properties ◽  
Lateral Force ◽  
Constitutive Law ◽  
Stone Masonry ◽  
Masonry Structures ◽  
Vibration Period ◽  
Analytical Studies

Abstract. Half-Dressed rubble stone (DS) masonry structures as found in the Himalayan region are investigated using experimental and analytical studies. The experimental study included a shake table test on a one-third scaled structural model, a representative of DS masonry structure employed for public critical facilities, e.g. school buildings, offices, health care units, etc. The aim of the experimental study was to understand the damage mechanism of the model, develop damage scale towards deformation-based assessment and retrieve the lateral force-deformation response of the model besides its elastic dynamic properties, i.e. fundamental vibration period and elastic damping. The analytical study included fragility analysis of building prototypes using a fully probabilistic nonlinear dynamic method. The prototypes are designed as SDOF systems assigned with lateral, force-deformation constitutive law (obtained experimentally). Uncertainties in the constitutive law, i.e. lateral stiffness, strength and deformation limits, are considered through random Monte Carlo simulation. Fifty prototype buildings are analyzed using a suite of ten natural accelerograms and an incremental dynamic analysis technique. Fragility and vulnerability functions are derived for the damageability assessment of structures, economic loss and casualty estimation during an earthquake given the ground shaking intensity, essential within the context of risk assessment of existing stock aiming towards risk mitigation and disaster risk reduction.

scholarly journals Structural renovation of residential building in Zagreb after the 22 March 2020 earthquake

2021 ◽  
Vol 73 (06) ◽  
pp. 633-648
Author(s):  
Stjepan Lakusic
Keyword(s):  
Seismic Analysis ◽  
Pushover Analysis ◽  
Residential Building ◽  
Structural Condition ◽  
Static Method ◽  
Seismic Resistance ◽  
Masonry Structures ◽  
Assessment Report ◽  
Nonlinear Static ◽  
Structural Condition Assessment

The phases that must be completed so that a building damaged in earthquake that struck Zagreb on 22 March 2020 can be renovated and strengthened to the required level of seismic resistance are presented in the paper. All phases are therefore presented, starting from the rapid and then detailed inspection, and continuing with preparation of the structural condition assessment report, preparation of renovation design and, finally, ending with realisation of work with expert supervision. A special attention is paid to structural analysis that is conducted using a nonlinear static method based on displacements, the so called pushover analysis, which is considered to be one of the most appropriate methods for seismic analysis of existing masonry structures. All procedures conducted in the scope of this renovation were realised in accordance with legislation that entered into force after the earthquake.

scholarly journals Seismic Vulnerability of Multi-Storey Buildings with Masonry Walls

2020 ◽  
Vol 8 (5) ◽  
pp. 4320-4323
Keyword(s):  
Seismic Behavior ◽  
Seismic Vulnerability ◽  
Pushover Analysis ◽  
Infill Wall ◽  
Braced Frame ◽  
Masonry Infill ◽  
Rigid Frame ◽  
Infill Panels ◽  
Recent Earthquakes ◽  
Masonry Infill Wall

In the seismic codes, lateral rigidity and strength of infill panels are ignored in the design. However recent earthquakes occurred in the world has shown that infill walls change the dynamic behavior of the frame. In this article we propose to investigate the effect of infill wall on the seismic behavior of framed concrete buildings. For this purpose, a framed reinforced concrete building is considered. An equivalent diagonal strut model is used for masonry infill. The strut properties are calculated according to the FEMA306 [7]. Nonlinear pushover analysis is used to assess the seismic behavior. The results show that introduction of the masonry infill wall in the analysis modifies the behavior of bare frame. There is a drastic change in the bending moments and shear forces. The modeling of infill wall transforms the rigid frame into braced frame.

scholarly journals Shear Walls Induced RC Structures

2021 ◽  
Vol 12 (2) ◽  
pp. 1827-1834
Author(s):  
Kesava Rao B, Et. al.
Keyword(s):  
Dynamic Analysis ◽  
Response Spectrum ◽  
Pushover Analysis ◽  
Shear Walls ◽  
Shear Wall ◽  
Lateral Force ◽  
Wind Pressure ◽  
Earthquake Response ◽  
Rc Structures ◽  
Seismic Forces

In recent years, the construction of skyscrapers has been on the rise to overcome the shortage of land. These buildings are subject to an external lateral force, such as an earthquake and wind pressure. Pushover analysis (POA) has been broadly used in predicting the earthquake response of structures, and shear walls have been shown to be lateral drag elements. Therefore, in the present work, the effect of placing a shear wall on the periphery symmetrically, the periphery asymmetrically and in the center of the building is performed using the ETABS software. Using the response spectrum methodand thetime history method, a dynamic analysis is performed. Responses such as floor shear, floor displacement, and lateral floor shifts due to seismic forces are evaluated for various locations of the shear wall. According to the results and analysis, the shear wall on the symmetrical periphery of the structure is reducing the displacement and deviation of the floor compared to other cases.

The Discussion on Lateral Load Distribution Mode while Structural Seismic Analysis is Proceeding

2011 ◽  
Vol 94-96 ◽  
pp. 1044-1048
Author(s):  
Jin Liang Han ◽  
Yun Xia Li ◽  
Zong Yun Mo
Keyword(s):  
Cross Section ◽  
Load Distribution ◽  
Seismic Analysis ◽  
Pushover Analysis ◽  
Lateral Force ◽  
Calculation Model ◽  
Seismic Load ◽  
Ansys Software ◽  
Distribution Mode ◽  
Lateral Load Distribution

In this study, the procedure of Pushover analysis has been put into effect, and following factors have been mainly researched in Pushover analysis: choosing the calculation model of structure and element; analyzing the yielding moment and limiting moment of cross section; posing the distribution pattern of lateral force; discussing the influence of high class mode of vibration on the structure. The following conclusions are given by analyzing a frame damaged by the seismic load with the help of the ANSYS software.

SEISMIC VULNERABILITY ASSESSMENT FOR SAN FRANCISCO TEMPLE IN MORELIA, MEXICO

2019 ◽  
Vol 3 (Special Issue on First SACEE'19) ◽  
pp. 207-2016
Author(s):  
Guillermo Martinez ◽  
David Castillo ◽  
José Jara ◽  
Bertha Olmos
Keyword(s):  
San Francisco ◽  
Seismic Vulnerability ◽  
Seismic Analysis ◽  
Three Dimensional ◽  
Middle Part ◽  
Seismic Demands ◽  
Modeling And Analysis ◽  
Seismic Records ◽  
Cracking Pattern ◽  
The Temple

This paper presents a first approximation of the seismic vulnerability of a sixteenth century building which is part of the historical center of Morelia, Mexico. The city was declared World Heritage by United Nations Educational, Scientific and Cultural Organization in 1991. The modeling and analysis of the building was carried out using a three-dimensional elastic tetrahedral finite elements model which was subjected to probabilistic seismic demands with recurrences of 500 yrs and 1000 yrs in addition to real seismic records. The model was able to correctly identify cracking pattern in different parts of the temple due to gravitational forces. High seismic vulnerability of the arched window and the walls of the middle part of the bell tower of the temple was indicated by the seismic analysis of the model.

Vibration Characteristics of Rotating Thin Disks—Part I: Experimental Results

2012 ◽  
Vol 79 (4) ◽  
Author(s):  
Ramin M. H. Khorasany ◽  
Stanley G. Hutton
Keyword(s):  
Frequency Response ◽  
Natural Frequency ◽  
Linear Theory ◽  
Lateral Force ◽  
Vibration Characteristics ◽  
Experimental Results ◽  
Rotating Disks ◽  
Critical Speeds ◽  
Applied Forces ◽  
Thin Disks

Analysis of the linear vibration characteristics of unconstrained rotating isotropic thin disks leads to the important concept of “critical speeds.” These critical rotational speeds are of interest because they correspond to the situation where a natural frequency of the rotating disk, as measured by a stationary observer, is zero. Such speeds correspond physically to the speeds at which a traveling circumferential wave, of shape corresponding to the mode shape of the natural frequency being considered, travel around the disk in the absence of applied forces. At such speeds, according to linear theory, the blade may respond as a space fixed stationary wave and an applied space fixed dc force may induce a resonant condition in the disk response. Thus, in general, linear theory predicts that for rotating disks, with low levels of damping, large responses may be encountered in the region of the critical speeds due to the application of constant space fixed forces. However, large response invalidates the predictions of linear theory which has neglected the nonlinear stiffness produced by the effect of in-plane forces induced by large displacements. In the present paper, experimental studies were conducted in order to measure the frequency response characteristics of rotating disks both in an idling mode as well as when subjected to a space fixed lateral force. The applied lateral force (produced by an air jet) was such as to produce displacements large enough that non linear geometric effects were important in determining the disk frequencies. Experiments were conducted on thin annular disks of different thickness with the inner radius clamped to the driving arbor and the outer radius free. The results of these experiments are presented with an emphasis on recording the effects of geometric nonlinearities on lateral frequency response. In a companion paper (Khorasany and Hutton, 2010, “Vibration Characteristics of Rotating Thin Disks—Part II: Analytical Predictions,” ASME J. Mech., 79(4), p. 041007), analytical predictions of such disk behavior are presented and compared with the experimental results obtained in this study. The experimental results show that in the case where significant disk displacements are induced by a lateral force, the frequency characteristics are significantly influenced by the magnitude of forced displacements.

scholarly journals Numerical modeling of reinforced concrete structures: static and dynamic analysis

2013 ◽  
Vol 66 (4) ◽  
pp. 425-430 ◽  
Author(s):  
Jorge Luis Palomino Tamayo ◽  
Armando Miguel Awruch ◽  
Inácio Benvegnu Morsch
Keyword(s):  
Reinforced Concrete ◽  
Numerical Model ◽  
Finite Elements ◽  
Dynamic Analysis ◽  
Time Integration ◽  
Great Accuracy ◽  
Constitutive Law ◽  
Published Data ◽  
Static And Dynamic Analysis ◽  
Plates And Shells

A numerical model using the Finite Element Method (FEM) for the nonlinear static and dynamic analysis of reinforced concrete (RC) beams, plates and shells is presented in this work. For this purpose, computer programs based on plasticity theory and with crack monitoring capabilities are developed. The static analysis of RC shells up to failure load is carried out using 9-node degenerated shell finite elements while 20-node brick finite elements are used for dynamic applications. The elasto-plastic constitutive law for concrete is coupled with a strain-rate sensitive model in order to take into account high loading rate effect when transient loading is intended. The implicit Newmark scheme with predictor and corrector phases is used for time integration of the nonlinear system of equations. In both cases, the steel reinforcement is considered to be smeared and represented by membrane finite elements. Various benchmark examples are solved with the present numerical model and comparisons with other published data are performed. For all examples, the path failure, collapse loads and failure mechanism is reproduced with great accuracy.

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