scholarly journals The implications of post-tensioning losses on the seismic response of Pres-Lam frames

2018 ◽  
Vol 51 (2) ◽  
pp. 57-69 ◽  
Author(s):  
Gabriele Granello ◽  
Alessandro Palermo ◽  
Stefano Pampanin ◽  
Tobias Smith ◽  
Francesco Sarti
Keyword(s):  
Seismic Response ◽  
Linear Time ◽  
Response Spectrum ◽  
Time History ◽  
Moment Capacity ◽  
History Analysis ◽  
Supplemental Damping ◽  
Column Joint ◽  
Post Tensioning ◽  
Wall Foundation

Since 2010, twelve post-tensioned timber (Pres-Lam) buildings have been constructed throughout the world. In high seismic areas, Pres-Lam technology typically combines unbonded post-tensioning tendons and supplemental damping devices to provide moment capacity to beam-column, wall-foundation or column-foundation connections. Over time creep within the timber elements leads to losses in post-tensioning forces reducing the connection moment capacity. This paper analyses how different post-tensioning loss scenarios, depending on the beam-column joint detailing, impact the building’s seismic response. Two case study buildings were designed and investigated using the Acceleration Displacement Response Spectrum (ADRS) method and Non-Linear Time History Analysis (NLTHA) to predict seismic performance. These buildings were considered to be located in areas of high and low seismic risk, leading to designs with and without the use of damping devices, respectively. The results show that the building with additional damping responded with similar peak displacements, even under extreme loss scenarios. In comparison, when supplemental damping was not used, peak displacements increased significantly with post tensioning losses.

Seismic Response Spectrum in Lieu of Time History Analysis for Subsea Structure Design

2017 ◽  
Author(s):  
George Wang ◽  
Michelle Loh ◽  
Yen-Tun Peng ◽  
Joanne Shen ◽  
P. E. Genesis ◽  
...  
Keyword(s):  
Seismic Response ◽  
Response Spectrum ◽  
Time History ◽  
Time History Analysis ◽  
Structure Design ◽  
History Analysis

scholarly journals Dynamic Analysis of Steel Silo

2020 ◽  
Vol 9 (1) ◽  
pp. 1986-1990
Keyword(s):  
Dynamic Analysis ◽  
Linear Time ◽  
Response Spectrum ◽  
Structural Response ◽  
Time History ◽  
Time History Analysis ◽  
Base Shear ◽  
Natural Period ◽  
History Analysis ◽  
Lateral Displacements

The structural response of any structure is the result of various dynamic phenomenon which lead to vibrations or shaking of the structure , depending on the duration of the ground motion, its frequency and time period. In the present work, dynamic analysis of a typical steel silo is done by using linear Time History Analysis and Response Spectrum method for earthquake Zone V as per Indian code. Two analyses are carried out namely, Time History Analysis (THA) and Response Spectrum Analysis (RSA) using STAAD.ProV8i software. The Load combinations are worked out as per IS-1893-2002. The results in terms of Fundamental natural period, Design Base shear, Lateral Displacements, are compared for the two different silo models considered in the present study.

Stability Analysis and Potential Seismic Capacity Evaluation of an Elliptic Paraboloid Latticed Shell

2012 ◽  
Vol 256-259 ◽  
pp. 2152-2160 ◽  
Author(s):  
Xiao Nong Duan ◽  
Zhu Juan Yang ◽  
Neng Tang ◽  
Xue Ting Chen
Keyword(s):  
Seismic Response ◽  
Structural Model ◽  
Linear Time ◽  
Response Spectrum ◽  
Time History ◽  
Initial Imperfection ◽  
Static Stability ◽  
Seismic Capacity ◽  
Elliptic Paraboloid ◽  
Response Characteristics

The stability and the potential seismic capacity of the double-layer elliptic paraboloid latticed shell roof structure of a stadium was analyzed and evaluated, performing by Midas Gen software. Firstly, the seismic response spectrum analyses and the linear time-history analyses were carried out respectively on two different analysis models: the integral structural model containing the lower support structure and the single latticed shell model. The seismic response characteristics and the potential seismic capacity of the models were compared and evaluated. Secondly, based upon the real detailed design of the stadium, the static stability of the latticed shell was analyzed, considering both the geometrical non-linearity and the initial imperfection. Thirdly, the influence of the effects of the vertical ground motion upon the latticed shell structure was studied. The analysis method adopted and the conclusions obtained can be used as references for the future similar engineering projects.

Seismic Response Analysis of Railway Frame Piers

2012 ◽  
Vol 517 ◽  
pp. 824-831
Author(s):  
Yun Xiao ◽  
Jun Qing Lei ◽  
Zhong San Li
Keyword(s):  
Seismic Response ◽  
Response Spectrum ◽  
Time History ◽  
Longitudinal Direction ◽  
Time History Analysis ◽  
Response Analysis ◽  
Vibration Modes ◽  
Seismic Response Analysis ◽  
Spectrum Method ◽  
History Analysis

By response spectrum method, superposition method based elastic time-history analysis and nonlinear time-history analysis of Newmark-β based linear increasing acceleration method, the finite element models of frame piers 21#~29# of the Ziya River Bridge on Tianjin to Baoding railway are established, and an assistant program code is generated to analyze seismic response of the frame pier. Results indicate that the vibration modes of frame piers are scattered. Only a few modes would be aroused in a narrow band spectrum. And the seismic response obtained by the response spectrum method is generally 10%~20% smaller than which obtained by the elastic time-history analysis. Under seismic excitations along the longitudinal direction, the ratio of displacement difference between two columns to the maximum value is generally liner increased with the increasing of the girder deviation from the centre of the pier beam. And the plastic hinge yielding would occur both at the bottom and the top of pier columns under excitations of the transversal direction. As a result, taking more than 30 vibration modes into account is suggested in a seismic response analysis or design calculation for frame piers. A time-history analysis is recommended as well. The evaluation of earthquake resistant capability of the transversal direction should consider both the bottom and top of the columns, and the anti-seismic capability design of the longitudinal direction is one of the key points for frame piers in the ductility design.

scholarly journals Effect of the Improved Pall Friction Damper on the Seismic Response of Steel Frames

2017 ◽  
Vol 7 (4) ◽  
pp. 1833-1837 ◽  
Author(s):  
P. H. Sarjou ◽  
N. Shabakhty
Keyword(s):  
Seismic Response ◽  
Linear Time ◽  
Steel Frames ◽  
Time History ◽  
Friction Damper ◽  
Base Shear ◽  
Absorbed Energy ◽  
Steel Bracing ◽  
History Analysis ◽  
Energy Absorbing

Energy-absorbing dampers are used to reinforce structures which are vulnerable to earthquakes. This study evaluates the performance of Improved Pall Frictional Dampers (IPFD) which is a type of Pall Frictional Damper (PFD). For this purpose, this study compares the performances of steel frames with concentric steel bracing reinforced by IPFD and steel frames with concentric steel bracing with no damper. Frames with different stories and pans were modelled in sap2000 and exposed to accelerograms of earthquakes for non-linear time history analysis. Results of analysis were studied; parameters such as story displacement, base shear and absorbed energy were compared in steel frames with damper and without damper.

scholarly journals Seismic Evaluation of Multi Storey Building with Ground Soft Story and with Infill Action

2021 ◽  
Vol 10 (6) ◽  
pp. 22-27
Author(s):  
mahaboob subhani* Shaik ◽  
Budda Beeraiah
Keyword(s):  
Spectrum Analysis ◽  
Linear Time ◽  
Response Spectrum ◽  
Time History ◽  
Time History Analysis ◽  
Ground Movement ◽  
Base Shear ◽  
Wall Area ◽  
History Analysis ◽  
The Impact

The improvements in (3D) three–dimensional underlying examination and processing assets have permitted the effective and safe plan of taller constructions. These constructions are the outcome of expanding metropolitan densification and financial suitability. The pattern towards continuously taller constructions has requested a move from the conventional strength based plan approach of structures to an emphasis on obliging the general movement of the design. Presently a day's supported cement (RC) divider outline structures are generally suggested for metropolitan development in zones with high SE danger. Presence of shear dividers bestows an enormous solidness to the sidelong power opposing arrangement of the RC building. Appropriate specifying of shear dividers can likewise prompt bendable conduct of such constructions during solid quake shaking. One of the remarkable boundaries impacting the shear divider (SD) SE (SE) conduct outline structures is the SD region proportion. In this manner a scientific examination is performed to assess the impact of Shear Wall Area to floor zone proportion (SW/FZP %) on the SE conduct of multistoried RC structures with delicate story at ground floor. For this reason, 12 structure plans that have Five, Eight and Twelve stories with SW/FZP % going somewhere in the range of 0.70% and 1.31% in the two ways are created. Here, the conduct of these plans under quake stacking is evaluated via doing Response Spectrum Analysis and Linear Time History Analysis utilizing primary examination programming E-TABS. Reaction Spectrum Analysis is finished by SE code IS 1893:2002. Straight Time History Analysis is completed by considering the three ground movement records to be specific Bhuj, Chamba and Uttarkasi. The primary boundaries considered in this investigation are the connection SW/FZP % has with base shear and rooftop dislodging, story uprooting and story float. The logical outcomes demonstrated that building plans with SW/FZP % equivalent to 1% acted sufficiently under tremor loads. Furthermore when the SW/FZP % expanded past 1% it is seen that the improvement of the SE presentation isn't as huge.

scholarly journals COMPARISON OF METHODS USED FOR SEISMIC ANALYSIS OF STRUCTURES

2017 ◽  
Vol 13 ◽  
pp. 20 ◽  
Author(s):  
Petr Čada ◽  
Jiří Máca
Keyword(s):  
Seismic Analysis ◽  
Linear Time ◽  
Dynamic Properties ◽  
Response Spectrum ◽  
Time History ◽  
Time History Analysis ◽  
Seismic Load ◽  
Eurocode 8 ◽  
History Analysis ◽  
Non Linear

This paper investigates effects of the seismic load to a structure. The article describes main methods of the definition and practical application of the seismic load based on the Standard Eurocode 8. There was made a comparison of all methods using the same structure. A simple two-storeyed concrete 2D-frame with fixed joints was chosen. A one another model with rigid beams for some calculations was defined. The second model can be used for hand-calculations as a cantilever with two masses. The paper describes main dynamic properties of the chosen structure. Seismic load was defined by lateral force method, modal response spectrum, non-linear time-history analysis and pushover analysis. The time-history analysis is represented by accelerograms. There were made linear and non-linear calculations.

Seismic Assessment of Existing Eccentrically Braced Frames According to NBCC and ASCE 41-13 Evaluation Procedures

2018 ◽  
Vol 763 ◽  
pp. 1164-1171
Author(s):  
Sanda Koboevic ◽  
Guillaume Porthier de Bellefeuille ◽  
Pierre Etienne Maheu
Keyword(s):  
Linear Time ◽  
Response Spectrum ◽  
Time History ◽  
Seismic Assessment ◽  
Systematic Evaluation ◽  
Braced Frames ◽  
Eccentrically Braced Frames ◽  
Frame Design ◽  
History Analysis ◽  
Original Frame

The seismic performance of an existing 8-storey EBF with shear-critical links located in Victoria, BC, is assessed. The frame is designed according to 1995 NBCC and the CSA S16-94 steel design standard. Seismic assessment is first performed in accordance with recommendations of the User’s Guide to NBCC 2015 using equivalent static force procedure, response spectrum analysis and linear time history analysis. A Tier 3 systematic evaluation according to ASCE 41-13 is then carried out using a linear static and dynamic procedure. Even though the original frame design was based on capacity design principles, both procedure revealed an inadequate strength of the frame members and the need for strengthening. Although the ASCE 41 procedure resulted in a less severe assessment, failures were predicted for most of the columns and for some outer beams. Considering bending as deformation-controlled action alleviated outer beam response.

Dynamic Analyses of a Self-Anchored Suspension Bridge under Seismic Excitations

2014 ◽  
Vol 580-583 ◽  
pp. 1687-1691
Author(s):  
Cheng Wang ◽  
Yan Xu Wang
Keyword(s):  
Seismic Response ◽  
Response Spectrum ◽  
Time History ◽  
Suspension Bridge ◽  
Main Beam ◽  
Response Spectrum Method ◽  
Seismic Excitations ◽  
Spectrum Method ◽  
History Analysis ◽  
Standard Response

The seismic response of the Wusong bridge was analyzed though the response spectrum method and the time-history method by adopting the MIDAS/CIVIL. The analysis results show that the longitudinal displacement of the main girder is much larger under longitudinal seismic input, so some inhibiting device or dampers should be used to avoid impacting. There is not coupling between longitudinal and lateral seismic excitations, while the seismic response of moment and shear force at the bottom of the main tower is much larger. On the contrary the seismic response of main beam and the main cable should be calculated under the longitudinal and vertical seismic excitations because of the coupling between the both of them. Furthermore, the artificial seismic wave fitting standard response spectrum was generated to conduct the time-history analysis and the results are much larger than the results from the response spectrum method.

Effects of Pier Stiffness on the Seismic Response of Continuous Bridges with Irregular Configuration

2014 ◽  
Vol 638-640 ◽  
pp. 1794-1802 ◽  
Author(s):  
Si Si Wei
Keyword(s):  
Seismic Response ◽  
Linear Time ◽  
Time History ◽  
Time History Analysis ◽  
The Other ◽  
Relative Stiffness ◽  
History Analysis ◽  
Non Linear ◽  
Internal Forces

The seismic response of 4-span continuous bridges with different configurations has been investigated. In the series of bridges studied, the height of the central pier varies from 5 m to 100 m, while the heights of all the other piers remain the same. Using non-linear time history analysis, the internal forces at the bottom of individual piers have been predicted for each case. The correlation between the relative stiffness of adjacent piers and the ratio between the seismic response at the bottom of adjacent piers has been studied. Based on the results, in order to guarantee approximately balanced seismic response among all piers of a given bridge, a range of the relative column stiffness of two adjacent piers has been proposed.

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