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Shaking Table Test On Masonry Structure Confined By Core-tie-column

Posted on:2011-07-27Degree:MasterType:Thesis
Country:ChinaCandidate:S W ZhaoFull Text:PDF
GTID:2132360308958530Subject:Disaster Prevention and Mitigation and Protection Engineering
Abstract/Summary:PDF Full Text Request
Many rural masonries collapse during Wenchuan earthquake in May the 12th 2008, which cause great loss on both properties and lives. Rural masonries have been a very weak part all through the ages due to lack of corresponding measures. Though traditional constructional column and ring beam technology works well on improving seismic behavior of masonries effectively, it didn't become widespread due to condition limits, whose quality is not easily satisfied as well. This reseach team comes up core-column constructional measure based on practical condition of rural masonries, but it still lack of study on masonry structure as a whole till now. This paper carries out a shaking table test on a full scale masonry confined by core-tie-column with two stories two bay and one depth. Main researches been done list as follows:①Consulting relative reference from home and abroad and discussing the aim of shaking table test, the scale of model,the choice of model form, measure method, choice of the earthquake ground motion and loading rule comprehensively.②Scheme the shaking table test, constructing the model, setting up the data gathering system, recording procedure and phenomena of test.③Analysing the varying history of the dynamic character of the structure, such as natural vibrating frequence, damping ratio, vibrating mode, stiffness, based on data from white noise condition.④Determining stress condition and effect of each part of structure during each working condition through strain analysis of reinforcement, surface the masonry wall and surface of the precast block.⑤Validity of impressing between motherboard and table-board, dynamic amplifying coefficient, equal seismic force, inter-story shear and ratio between shear and gravity are studied.⑥In order to discuss displacement response of model strcture, inter-story drift has been analyzed and corresponding curves have been drawn. Torsional displacement response is also discussed through calculating and fist mode of acceleration to displacement hysteretic curve is attained by wave filtering.Test together with analysis show conclusions as follows:①As a new constructional technology, core-tie-column technology improves seismic behavior, deformability and energy dissipation capacity of masonry considerably and ensures stucture's integrity and no collspsing during rare earthquake of 9 degree. After a level crack at the bottom of model becomes transfixion, core-tie-column maintains structure's bearing capacity, as avoid shear failure at the bottom. The aim for"no damage in small earthquake, repairable under moderate earthquake and no collapsing with strong earthquake"at 9 degree level is achieved.②Along with the increasing of ground motion, natural frequence of the model in lateral and longitude has reduced by 4.75% and 1.76% respectively. Dampings in the direction of X and Y lie range from 0.011 to 0.016 and only a little variety has taken place all through the load history. The vibrating mode of the structure both in the direction of X and Y vary from bending form to shearing form.③Torsional response of the second story is great than the first floor's under ground motion and these response will rapidly increase if it is under a three dimensional seismic motions. Torsional displacement and torsional angle of the model structure are mainly small. Only an anglel of 7×10-4 radian is get when it's under a rare earthquake of 9 degree.④Inter-story drifts increase along ground motion, and are mainly small also. The greatest value is 1/625 only.⑤From acceleration to displacement hysteric curve ,we can find that: energy artifical ground motions carry near the first vibrating mode is more than that of a natural one; the first story dissipate more energy than the second story at the first vibrating mode; due to torsional composition, when we can see a distortion take place in the hysteric curve especially when ground motion is strong or a three dimensional ground motion is load, the second story disspate more torsional enery than the first story.
Keywords/Search Tags:Core-Column, Masonry, Shaking Table Test, Full Scale Model, Seismic Behavior
PDF Full Text Request
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