基于性能的砌体结构加固与修复研究

发布时间：2018-05-19 13:24

本文选题：砌体结构 + 后张预应力加固　；参考：《中国地震局工程力学研究所》2015年博士论文

【摘要】：我国现存着大量的未经抗震设防或按老旧规范抗震设防的砌体建筑,为了避免这些建筑在地震作用下的严重破坏,需要对其进行加固。近年来发生的汶川地震和芦山地震中,很多砌体结构损伤严重,但尚未倒塌,这些砌体结构是否可以修复,如何修复,修复后抗震性能有什么变化,目前还没有系统的研究可以借鉴。本文在基于性能的地震工程框架下,对砌体结构进行抗震加固与震后修复,并通过足尺结构试验评估其性能。本文主要工作如下:1.对某老旧砌体结构采用后张预应力技术进行抗震加固,并对加固后砌体结构进行了双向拟静力试验。附加预应力水平采用砌体结构抗压强度设计值的20%,在提高承载力的同时避免剪压破坏。本文详细介绍了后张预应力加固二层砌体结构模型的加固流程,拟静力试验的加载和测量方案,并对砌体结构的损伤程度进行了分析和评估。2.对采用后张预应力技术加固的砌体结构进行数值模拟。分别采用MSC.Marc和OpenSEES软件建立了加固砌体结构的精细化有限元模型和宏观力学模型。精细化有限元模型采用连续化方法和弹塑性损伤模型模拟砌体的破坏过程;而宏观力学模型采用剪切弹簧模拟墙片的宏观力学行为,通过分析50个后张预应力加固砌体墙片的试验数据,回归了加固墙片的开裂荷载计算公式。通过精细化有限元模型和宏观力学模型得到的滞回曲线与试验曲线的对比可知,这两种建模方法与试验吻合的较好,可以为该种结构的抗震性能研究提供一定的参考。3.未加固砌体结构拟静力试验。预应力加固结构拟静力试验后结构的第二层破坏的较轻,刚度损伤较小。为了对比加固效果,本文将一层用钢梁固定,而将预应力筋值调整为结构第二层自重对第一层的压应力,对第二层结构进行加载,模拟未加固结构的首层力学性能。通过对比可知,预应力加固可使结构的峰值承载力提高至未加固结构的两倍左右,且结构的耗能能力也大幅度增加。4.基于性能的砌体结构修复研究。对上述试验过后的损伤结构进行损伤评估后,综合考虑费用、工期和修复后承载力三方面的因素确定修复目标,根据修复目标选择增设构造柱和水泥砂浆钢筋网面层两种加固方法对损伤结构进行修复,通过修复过程中对工期和费用的量化可知修复结构与新建结构相比可大大减少费用、缩短工期。通过修复结构的拟静力试验可知,修复结构的峰值承载力分别是未加固结构的2.84倍,预应力加固结构的1.32倍,满足修复目标的要求。
[Abstract]:In our country, there are a large number of masonry buildings that have not been fortified by seismic fortification or in accordance with old and old codes. In order to avoid the serious damage of these buildings under earthquake action, it is necessary to reinforce them. In recent years, many masonry structures have been severely damaged in Wenchuan and Lushan earthquakes, but they have not collapsed. There is no systematic research on how to repair, how to repair and repair the seismic performance, and there is no systematic study for reference. In this paper, under the framework of performance based seismic engineering, the masonry structure is reinforced and repaired after the earthquake, and its performance is evaluated through a full scale structure test. The main work is as follows: 1. after a old masonry structure is adopted. The tensioned prestress technique is reinforced by earthquake resistance, and the reinforced masonry structure is subjected to bi-directional pseudo static test. The additional prestress level is 20% of the design value of the compressive strength of the masonry structure, which can improve the bearing capacity while avoiding the shear failure. In this paper, the strengthening process of the post tensioned two layer masonry structure model is introduced in detail, and the pseudo static force is proposed. The loading and measuring scheme of the test and the damage degree of the masonry structure are analyzed and evaluated by.2.. The numerical simulation of the masonry structure strengthened by post tensioned prestressing technology is simulated. The finite-element model and macroscopic mechanical model of the reinforced masonry structure are established by using the software of MSC.Marc and OpenSEES. The failure process of the masonry is simulated by the continuous method and the elastoplastic damage model, while the macro mechanical model uses the shear spring to simulate the macroscopic mechanical behavior of the wall slices. Through the analysis of the experimental data of 50 post tensioned masonry walls, the calculation formula for the cracking load of the reinforced wall is regress. The comparison between the hysteresis curve obtained by the mechanical model and the test curve shows that the two modeling methods are in good agreement with the test. It can provide some reference to the pseudo static test of the.3. unreinforced masonry structure for the study of the seismic performance of this structure. The second layers of the prestressed reinforced structure after the pseudo static test structure are lighter and stiffness loss. In order to compare the reinforcement effect, the first layer is fixed with the steel beam, and the value of the prestressed reinforcement is adjusted to the pressure stress of the second layer weight to the first layer, and the second layer structure is loaded to simulate the first layer mechanical properties of the unreinforced structure. By contrast, it can be seen that the prestressed reinforcement can improve the peak load bearing capacity of the structure to the unreinforced. The structure is about two times of the structure, and the energy dissipation capacity of the structure increases a lot of.4. based masonry structure repair research based on performance. After the damage assessment of the damage structure after the test, three factors of the cost, the time period and the post repair capacity are considered, and the construction column and the cement sand are selected according to the repair target. The damage structure is repaired by two methods of reinforcement. Through the quantification of time and cost in the process of repair, it can be found that the repair structure can greatly reduce the cost and shorten the time limit compared with the new structure. By the pseudo static test of the repair structure, the peak value bearing capacity of the repaired structure is 2.84 times as high as that of the unreinforced structure. The stress reinforcement structure is 1.32 times that of the repair target.
【学位授予单位】：中国地震局工程力学研究所
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TU364

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