谈底框砖砌体房屋结构抗震设计

随着市场经济的不断发展,在中等城市,多层砌体结构房屋尤其是多层砖砌体结构房屋,由于构造简单、造价低廉、施工方便以及能就地取材等优点,在今后相当长的时间里,一直是我国民用建筑和公共建筑的主要结构形式之一.底部框剪多层砌体房屋在我国地震区一些中小城市的临街建筑中已被广泛采用,并有继续扩大使用的趋势.房屋底部采用大空间的框剪结构,可用作商场、餐厅或停车场等,上部采用砌体结构,可用作住宅、办公用房或宾馆客房.底部框剪多层砌体房屋由钢筋混凝土框架--抗震墙和上部砌体结构两种承重和抗侧力体系构成,底部刚度小于上部,是一种上刚下柔结构.     

浅谈多层砖混结构房屋抗震设计中的关键技术

多层砖混结构房屋由于砌体结构自身材料的脆弱,整体性差,致使房屋抗震性能较低.因此,必须把抗震措施作为重要的课题进行探讨.本文通过分析地震震害特点,及抗震设计中应考虑的主要因素,针对抗震承载力的计算,实践中柱和圈梁的设置等问题进行探讨.     

多层砖混结构房屋的抗震设计探讨

多层砖混砌体房屋由于组成的基本材料和连接方式决定了其脆性性质,变形能力小,导致房屋的抗震性能较差.从建筑平面和立面的布局、房屋的层数和高度、纵墙和横墙的布置、提高砂浆强度、圈梁和构造柱以及水平钢筋的放置等多个方面来进行探讨,从而改善砌体结构延性,提高房屋的抗震性能.     

浅谈底框中底层框架的结构设计注意事项

底部框架剪力墙砌体房屋(以下简称底框结构)是指底部一层或两层为空间较大的框架一剪力墙、上部为多层砌体的房屋.底框结构是我国现阶段经济条件下特有的一种结构,从抗震上讲它是一种不合理的结构形式,但限于我国当今的经济发展水平,目前还无法取消,因此在我国内地及广大中西部地区临街建筑中仍普遍采用.其具有"头重脚轻"、上刚下柔,的特点,为保证实现"小震不坏,中震可修,大震用不倒"的抗震原则,<建筑抗震设计规范(GB50011-2001)>(以下简称<抗规>)对底部框架层与上层刚度比做出了明确规定,必须在底部框架中布置一定数量的的抗震墙.     

多层砖混房屋抗震性能分析

本文通过对多层砖混结构的震害进行分析,并根据砖混房屋结构特点,结合自身设计经验,提出在砖混房屋抗震设计中应注意的几个问题及采取的相应措施,对多层砌体房屋的抗震设计具有重要的指导意义。     

简述砌体结构裂缝产生的原因和防治措施

多层砌体结构建筑在我国应用广泛,其中以居住建筑为主.随着科技的发展,技术的进步,以及制度的完善,砌体结构房屋的质量得到了很好的保证,但是砌体结构墙体裂缝的问题依然无法根治.砌体结构墙体裂缝产生的原因主要有以下几种:不均匀沉降,温度变化,建筑材料自身,施工质量,使用不当等.产生裂缝的建筑,轻则影响建筑的正常使用及结构整体抗震性能,重则危机结构安全,给国家以及人民群众的生命财产安全带来巨大损失.     

多层砖混基础设计及上部结构抗震构造措施的几点建议

0前言任何建筑物都通过基础将上部结构的各种作用传给地基,基础的好坏直接影响整个建筑的安全性。另外经查《建筑抗震设计规范》(GB50011-2001),濮阳市抗震设防烈度为7度,设计地震加速度O.15g,可见濮阳市的地震形势十分严峻,而且砌体是一种脆性结构,其抗拉和抗剪能力均低,在强烈地震作用下,砖结构易于发生脆性的剪切破坏,从而导致房屋的破坏甚至倒塌,因此砌体结构中的抗震构造措施是砌体设计中的重要组成部分。故总结几年的设计经验,对多层砖混基础设计及其上部抗震构造措施归纳几点建议以供参考。     

多层砖混结构房屋的抗震设计探讨

多年来砖混房屋是我国当前建筑中使用最广范的一种建筑形式;其中民用住宅建筑中约占90%以上。在地震设防地区,多层砖混砌体房屋由于组成的基本材料和连接方式决定了其脆性性质,变形能力小,导致房屋的抗震性能较差;因此改善砌体结构延性,提高房屋的抗震性能具有极其重要意义。     

钢筋混凝土及砖石结构学习要点(上)

本学期的学习内容分为两部分:第一部分为钢筋混凝土整体房屋结构,其中包括单层厂房结构和多层与高层房屋结构两章的内容。第二部分为砌体(砖石等)结构。房屋抗震设计基本知识不在考查范围之内。     

建筑砌体结构的发展历史及优越性体现

本文介绍砌体结构的古代悠久历史和解放以来我国砌体结构的发展,以及现代新材料、新技术、新结构的研究与应用.并详细阐述砌体结构的优越性.最后通过实例来分析多层砌体建筑的经济价格.     

多层砖混房屋抗震设计需注意的问题及改进措施

本文通过对多层砖混房屋的震害、抗震概念设计、一般构造措施的阐述,提出了一些增强多层砖混房屋抗震能力的具体措施。总之,经过合理的抗震设计,构造得当,保证施工质量,砖混结构房屋是具有一定抗震能力,并且该结构仍将是城乡建筑中的主要结构形式之一。     

应用芳纶纤维加固砖砌体的抗震性能

以一砌体试件试验，并结合工程实例，论证了芳纶纤维加固后的砖砌体抗震耗能能力明显增强，延性显著提高，抗震性能得到有效改善，该方法适合对砌体结构进行抗震加固。     

Distinct Element Modelling of Unreinforced Masonry Wall Under Seismic Loads with and without Cable Retrofitting

To retrofit and strengthen existing unreinforced masonry (URM) structures to resist the potential earthquake damages has become an important issue in Australia.In order to secure the performance of URM under seismic loading in the future,a research project was carried out aimed at developing a simple and high strength seismic retrofitting technique for masonry structures.A series of experimental testing on URM walls retrofitted with an innovative technique by cable system have been conducted.The results indicated that both the strength and ductility of the tested specimens were significantly enhanced with the technique.An analytical model which is based on Distinct Element Method (DEM) has also been developed to simulate the behaviour of URM walls before and after retrofitting.The model is then further developed by applying a seismic wave to the wall to simulate the wall behavior under earthquake loads before and after retrofitting.     

Distinct Element Modelling of Unreinforced Masonry Wall Under Seismic Loads with and without Cable Retrofitting

To retrofit and strengthen existing unreinforced masonry (URM) structures to resist the potential earthquake damages has become an important issue in Australia. In order to secure the performance of URM under seismic loading in the future, a research project was carried out aimed at developing a simple and high strength seismic retrofitting technique for masonry structures. A series of experimental testing on URM walls retrofitted with an innovative technique by cable system have been conducted. The results indicated that both the strength and ductility of the tested speci-mens were significantly enhanced with the technique. An analytical model which is based on Dis-tinct Element Method (DEM) has also been developed to simulate the behaviour of URM walls be-fore and after retrofitting. The model is then further developed by applying a seismic wave to the wall to simulate the wall behavior under earthquake loads before and after retrofitting.     

Experimental study on improving seismic behavior of load-bearing masonry wall made of autoclaved aerated concrete

To investigate the seismic behavior of autoclaved aerated concrete load-bearing masonry wall（AACLMW）, a piece of control block wall without constructional measures and five pieces of block walls with different constructional measures were tested under low reversed cyclic loading which imitated low to moderate earthquake force. The seismic behavior of AACLMW with different constructional measures in terms of failure mode, hysteretic curve, deformation capacity and displacement ductility was studied and compared with that without constructional measures. The experimental results indicate that the constructional measures comprising constructional columns and horizontal concrete strips are effective for improving the seismic behavior of AACLMW. The study in this paper can provide a reliable experimental basis for further analysis and engineering application of AACLMW in the future.     

Modelling of URM Walls Retrofitted with Cable: A Comparison Between a Basic Mechanical Model and Distinct Element Method

The Australian love of "heritage" buildings (most of them are unreinforced masonry (URM)) means that greater attention is required to secure their performance under seismic or impact loading in the future. A research project has been carried out to develop a new, economic and high strength retrofitting technique for masonry structures. A series of experimental testing on URM walls retrofitted with an innovative technique by cable system have been conducted. In this paper, an analytical model which is based on distinct element method (DEM) is developed to simulate the behaviour of retrofitted walls. In DEM, a solid is represented as an assembly of discrete blocks. Joints are modelled as interface between distinct bodies. It is a dynamic process and specially designed to model the behaviour of discontinuities. In order to assist the practising engineers to design this new retrofitted wall system, a simple mechanical model was also developed to predict the strength of the retrofitted walls. The results obtained from this simple mechanical model are compared with those from both experiments and distinct element model.     

浅谈混合结构房屋墙体开裂原因及防治措施

对混合结构房屋墙体开裂产生的原因进行分析,并提出了相应的防治措施。     

砌体结构的研究及新材料的应用

简要介绍了建国以来砌体结构的发展、新型砌体材料、砌体结构理论研究方面取得的成就。并对未来砌体结构的发展提出建议。     

Experiment and numerical simulation on axial compressive performance of autoclaved fly ash solid brick masonry columns

To study the influence of slenderness on the axial compressive performance of autoclaved fly ash solid brick masonry columns, compression experiments were conducted on 12 samples of autoclaved fly ash solid brick masonry column and 4 samples of fired clay brick masonry column. The damage patterns and compressive performance were compared and analyzed. The experimental results indicate that the compressive bearing capacity decreases as slenderness increases from 3 to 18, and the compressive bearing capacity of the autoclaved fly ash solid brick masonry columns is lower than that of the fired clay brick masonry columns. The formulae for the axial compressive bearing capacity of autoclaved fly ash solid brick masonry columns were derived based on the experiments. The nonlinear FEA program ANSYS was adopted to simulate the behaviors of masonry columns. By comparing the simulation results and experimental results, it is shown that the simulation results agree well with the experimental ones. The rationality and applicability of the simulation results were verified.     

Numerical Derivation of Strain Rate Effects on Material Properties of Masonry with Solid Clay Bricks

In this paper, numerical method is used to study the strain rate effect on masonry materials. A typical unit of masonry is selected to serve as a representative volume element (RVE). Numerical model of RVE is established with detailed distinctive modeling of brick and mortar with their respective dynamic material properties obtained from laboratory tests. The behavior of brick and mortar are characterized by a dynamic damage model that accounts for rate-sensitive and pressuredependent properties of masonry materials. Dynamic loads of different loading rates are applied to RVE. The equivalent homogenized uniaxial compressive strength, threshold strain and elastic modulus in three directions of the masonry are derived from the simulated responses of the RVE. The strain rate effect on the masonry material with clay brick and mortar, such as the dynamic increase factor (DIF) of the ultimate strength and elastic modulus as a function of strain rate are derived from the numerical results.