scholarly journals Seismic Retrofitting of a Structure with Soft Storey and Floating Column.

2021 ◽  
Vol 1197 (1) ◽  
pp. 012073
Author(s):  
Shubham Velani ◽  
Kuldeep R Dabhekar ◽  
Prashant Y Pawade ◽  
Isha P khedikar

Abstract Tremors are called one in everything about preeminent erratic and annihilating of every cataclysmic event, be that as it may, the flighty idea of the incidence of those seismic tremors makes it inconvenient to hinder loss of living souls and annihilation of properties, if the constructions don’t seem to be designed to oppose such seismic tremor powers. During this paper, a shot has been made to review set up irregularities specifically torsional irregularity and re-entrant corners within the frame structure. These inconsistencies square measure made according to IS 1893:2016 (part1) code. Irregular model and regular model were considered which were analyzed exploitation ETABS 2018 to see the unstable reaction of the structure. The models were analyzed exploitation static and dynamic ways, parameters thought-about being displacement, storey drift, torsional irregularity.

2021 ◽  
Vol 1197 (1) ◽  
pp. 012050
Author(s):  
Yash Chhatani ◽  
Prashant Y Pawade ◽  
Kuldeep R Dabhekar ◽  
Isha P khedikar

Abstract Tremors are called one in everything about preeminent erratic and annihilating of every cataclysmic event, be that as it may, the flighty idea of the incidence of those seismic tremors makes it inconvenient to hinder loss of living souls and annihilation of properties, if the constructions don’t seem to be designed to oppose such seismic tremor powers. During this paper, a shot has been made to review set up irregularities specifically torsional irregularity and re-entrant corners within the frame structure. These inconsistencies square measure made according to IS 1893:2016 (part1) code. Irregular model and regular model were considered which were analyzed exploitation ETABS 2018 to see the unstable reaction of the structure. The models were analyzed exploitation static and dynamic ways, parameters thought-about being displacement, story drift, torsional irregularity.


2018 ◽  
Vol 763 ◽  
pp. 259-269
Author(s):  
George Webb ◽  
Kanyakon Kosinanonth ◽  
Tushar Chaudhari ◽  
Saeid Alizadeh ◽  
Gregory A. MacRae

Beam column joint subassemblies in steel moment frames often have simply-supported gravity beams framing into the joint in the perpendicular direction. When these subassemblies undergo lateral displacement, moments enter the column from the beams. Some of these moments are directly applied from the in-plane beam and slab stresses as they contact the column, and additional moments occur as the slab causes the perpendicular simply supported beams to twist. In most design codes around the world, no explicit consideration of these moments is performed even though they may increase the likelihood of column yielding and a soft-storey mechanism. This paper quantifies the magnitude of these perpendicular beam twisting moments in typical subassemblies using inelastic finite element analysis. It is shown that for beam-column-joint-slab subassemblies where the primary and secondary beams are fully welded to the column, the addition of slab effects significantly increases the total stiffness and strength of the composite frame structure. In addition to this, it is also shown the twisting moment demand of the secondary beams increased the frames strength by approximately 2% for an imposed drift of 5% for the subassembly investigated when no gap was provided between slab and the column. It was also shown the twisting moment demand of the secondary beams increased the frames strength by approximately 10% for a maximum imposed drift of 5% for the subassembly investigated when a gap was provided between the slab and the column.


2011 ◽  
Vol 255-260 ◽  
pp. 644-648
Author(s):  
Yan Xia Ye ◽  
Hua Huang ◽  
Dong Wei Li

Comparative analyses of twenty-eight finite element structures with filler walls were established to study dynamic characteristics of RC frame structures under seismic waves. The results of these analyses show that filler walls have little influence on vibration modes of the structure. But as a result of soft storey in the bottom of building caused by reduction of the filler walls, vibration modes have a great influence. As the stiffness of filler wall decrease, the stiffness of soft storey decrease shapely, vibration mode curve becomes much smoother. Considering the filler wall has influence on the vibration periods of framework, the reduction factor of 0.7 should be taken. The influence of filler wall to the value of lateral drift and storey displacement angle of frame can not be ignored. The main effect factors to the dynamic characteristics of framework are included quantity, location, material of the fill wall and the selection of seismic waves.


2011 ◽  
Vol 82 ◽  
pp. 485-490 ◽  
Author(s):  
Domenico Asprone ◽  
Fatemeh Jalayer ◽  
Andrea Prota ◽  
Gaetano Manfredi

Extreme loading conditions such as man-made malicious actions, fires or natural events could induce local failure mechanisms (e.g., a loss of a member) which may trigger progressive collapse. The design or the assessment of a critical infrastructure needs to address the possibility of such an extreme circumstance taking place during its effective life-time. It is observed that blast-induced progressive collapse mechanisms involve non-linear structural behavior similar to that due to earthquakes. This work focuses on probabilistic analysis of progressive collapse of a typical RC structure, induced by a blast event. The objective is to verify the effectiveness of seismic retrofitting schemes against explosions and the eventual progressive collapse. The probabilistic analysis is performed by taking into account the uncertainties in loading such as planar configuration and amplitude of the blast loading. A standard Monte Carlo simulation method is employed to generate various realizations of the uncertain parameters within the problem. For a given realization, various component-level dynamic analyses are preformed within a certain range of distance, in order to quantify and locate the damage induced by shock wave on structural elements. As a case study, a 5-storey reinforced concrete frame structure designed for gravity loading only is considered. As possible retrofitting schemes, steel bracing, FRP wrapping and RC jacketing are compared. The probability of collapse considering both blast and earthquake for the structure before and after retrofit are compared.


Author(s):  
Hiroyuki Nakahara ◽  
Yukiko Ashida

The authors have been developing a seismic retrofitting method using concrete-filled steel tubular (CFT) members as a diagonal brace. The features of the method are easy set-up and low-cost because we made the enforcing devices lightweight and a simple connecting method to the existing structures. This method provides many advantages for the buildings located at the places where are difficult to transport heavy materials and equipment. An experimental construction for the seismic retrofit was conducted at the 2-story RC building on an isolated island in Japan. The construction was succeeded by only three persons in two days without heavy equipment. This paper is consisted of the reports of the constructing process and the loading test of the connecting part of the method. The trial construction includes a new detail of the connection. Two specimens were made and tested to estimate the lateral load carrying capacity of the connection.


2013 ◽  
Vol 791-793 ◽  
pp. 750-753
Author(s):  
Ping Huai Mao ◽  
Bing Zhai ◽  
Jing Xi Li

Coal mine horizontal belt extension transfer machine is designed in order to solve the mine loading efficiency is not high; especially the most loading mechanical failed to solve continuous loading problem. This machine can also load a whole column tramcars and tramcars without modification with direct use, efficiency improve obviously. This paper first introduces transfer machine structure and working process, and introduces its important part tractor, structure and main function; Then as the main force of tractor parts, we frame for stress analysis, and set up the frame of 3-D model; Finally put the model into ANSYS of its structure statics analysis, and according to the result of analysis frame structure optimization. We will use the same approach to the design of tractor other components, finally complete the complete tractor. Through the study of tractor, summarizes the design methods for other similar mechanical similar provide a theory basis for the design.


2007 ◽  
Vol 347 ◽  
pp. 285-290
Author(s):  
Elena Candigliota ◽  
Alain Le Maoult

Tests on shaking table have been carried out on a 3D full scale infilled r.c. frame specimen (55 tons). These tests have been performed by the EMSI Laboratory of C.E.A. Saclay (France) together with a research team of the Universities of Chieti-Pescara (Italy), Roma Tre (Italy) and Patras (Greece). These tests are included in Ecoleader European research program. Many characterization tests of infill components (mortar and bricks) have been performed in the SCAM Laboratory of the University of Chieti-Pescara while tests on masonry walls were made in the laboratory of University of Rome 3. The structure represents the first floor of a two floors frame structure previously tested. The mockup is a full-scale one storey rc infilled frame with four columns, 3 meters high, with about 4 meters side square floor and infilled with double bricks wall. The main aim is to get information about the behavior of real structures. The instrumentation with about one hundred channels was set up to measure the rc frame response and the different behavior of the double walls during the tests. First, monodirectional and bidirectional tests at low seismic intensity (0.10 g and 0.15 g PGA levels) have been performed on the bare frame in order to characterize its structural characteristics and to check the design provisions. Then, the bare frame has been infilled and other tests have carried out at increasing seismic intensity in order to define its serviceability and ultimate limit states. Monodirectional and bidirectional tests up to 0.45 g PGA level were carried out. The last sequence included a monodirectional test on the infilled frame with only two walls. The high seismic input (0.55 g PGA level) was parallel to the direction of the walls. In this paper, research program and some main test results are presented.


Author(s):  
Feng Gao ◽  
Yonghua Xiong ◽  
Lei Tian ◽  
Farong Du ◽  
Guoyan Xu

The three-dimensional geometric model of the fringe-beam frame had been built based on the frame structure of a light truck. In order to optimize the frame structure, the finite element model of the frame and the suspension system were set up. Considering the influence of suspension on frame dynamic performance, the modal properties of the frame model was analyzed in the commercial analysis program ANSYS, using two different methods. Based on the experiments, it was verified that combining MPC184 elements and spring elements Combin14 is a better way to simulate suspension compared to using spring finite elements only. Furthermore, the combined simulation results coincide with experimental modal analysis results, which were conducted thereafter. Subsequently, the frame stress-strain distribution rules and dynamics response were calculated under the random road spectrum excitation, and the frame dynamic parameters were obtained. This study provides some theoretical bases for frame structure improvement, and proposes an optimum method to simulate suspension. The results have direct significance in ensuring the stability, comfort and reliability of a light truck frame.


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