砌体墙开设门窗洞口会导致其平面内的刚度及抗剪承载力降低,而开洞砌体墙的分布不均衡又使得地震作用下整体结构出现扭转变形,从而加大地震震害.以3片开洞砌体墙的拟静力试验为原型,采用ABAQUS有限元程序对3个模型(未加固的开洞砌体墙A-1、单面钢筋网加固的开洞砌体墙A-2、单面钢筋网和钢窗框同时加固的开洞砌体墙A-3)进行建模和非线性计算,得出了在低周反复水平荷载作用下砌体墙的荷载-位移滞回曲线,并通过对滞回曲线的处理,对比分析了应力云图、应变云图、滞回特性、砌体墙耗能、骨架曲线和刚度退化曲线,验证了有限元模型的合理性和有效性,同时也验证了加固措施的有效性.

根据北京地区既有农村住宅典型砖木结构(木柱支撑,木屋盖,外砖墙)的抗震性能特点以及农宅砖木结构未抗震加固模型的振动台试验损伤特征,结合北京地区8度抗震设防的要求,提出以下加固结构方案:①配筋砂浆带圈梁、②前檐加设钢门窗框、③房屋四角钢丝网砂浆加固,并设计2/3大比例缩尺模型,进行了8个工况振动台试验,研究了北京地区既有农村住宅单层砖木结构房屋上述抗震加固方法的有效性.通过与未加固模型的振动台试验损伤结果、动力特性、动力反应和频谱分析比较,验证了提出的加固方案的抗震性能和可行性.振动台试验结果表明:加固后模型达到了“小震不坏、中震可修、大震不倒”的抗震设防目标,为制定这类结构的抗震加固方案提供了依据.

A rural building in Beijing is a typical single-story brick-timber structure built in 1980 's.There aren't any aseismic measure in the building. The building by aseismic strengthening could achieve the design target of operational after minor earthquake,repairable damage under middle earthquake,and collapse prevention under rare earthquake. The structural aseismic key strengthening technologies against seismic fortification intensity in Beijing are introduced.

Brick-wood houses are widely used in rural in China with no earthquake-proof housing construction measures in general. Wooden frame structures,crossbeam and other related components have no reliable connections,which are easily fell off and destroyed by vertical and horizontal earthquake force. Combined with actual project,the structural seismic technology optimize study on the typical structure of wood column as the vertical load-bearing system are introduced,the study results show that the structure system with the seismic reinforcement technology optimization can meet the seismic requirements of the region,and the economic effect is good.

The investigation and seismic reinforcements of typical rural dwellings in Beijing have been sped up since Wenchuan earthquake in 2008.Based on the investigations of the seismic performances of typical rural dwellings in 13 districts of Beijing,the information of structure system,construction time and construction materials were summarized.Based on seismic damage characteristics of similar rural dwellings in Wenchuan earthquake,the actual seismic performances of rural dwellings in Beijing were analyzed and security risks as well as countermeasures were proposed.The research provides reference for design,construction and research of seismic reinforcements of rural dwellings in Beijing.

This paper presents seismic retrofit for the single-story brick-wood structure representative of existing rural buildings in Beijing.The retrofitting effectiveness was examined through large-scale shaking table tests on the unretrofitted and retrofitted specimens.The test results indicate that,for the unretrofitted specimen,the front brick columns deform and damage severely when subjected to the longitudinal motions,because large of lateral stiffnesses difference exists between the front and back longitudinal walls.The brick gables experience significant out-of-plane deformation,resulting in diagonal cracks.The unretrofitted specimen is cracked under minor earthquakes,significantly damaged under design basis earthquakes,and approaches to collapse under rare earthquakes.The method of seismic retrofit was proposed based on the test results of the unretrofitted specimen,including the addition of a steel doorframe,steel window frames and steel plate collar beams,and the strengthening of the brick gables and columns by cement mortar reinforced with steel mesh.Shaking table test results show that the retrofit method significantly improves the earthquake-resistant capacity of the brick-wood building structure,and the retrofitted specimen can achieve the design objective of 'operational under minor earthquakes,repairable damage under design basis earthquakes,and collapse prevention under rare earthquakes'.

In order to investigate the seismic resistant capacity of typical brick-timber structures in rural areas of Beijing,a 2/3 scaled typical brick-timber structure model with timber columns,wood roof and brick peripheral walls was designed and tested on a shaking table,which is a single-story brick-timber structure with three bays.According to the national seismic design code GB50011,the seismic precautionary intensity is 8 for most rural areas in Beijing.Different dynamic base excitation levels,such as design small earthquake with PGA=0.072g,design middle earthquake with PGA=0.2g and great earthquake with PGA=0.4g respectively,were input to the model.Dynamic responses and cracking characteristics on the brick walls were recorded.Based on the test results,the seismic resistant capacity of the model was obtained and analyzed.It was found that due to different lateral resisting stiffness of the front wall and the back wall for different door or window openings,the response of the front wall was far greater than that of the back wall in the longitudinal direction.This leads to out plan flexure of the end brick wall,some key technologies for how to strengthen and retrofit the existing rural brick-timber structure in Beijing are pointed out.

Through the energy consumption diagnosis,the calculation and analysis of solar energy saving efficient and solar heating fraction of solar floor heating system in rural residential buildings in Beijing,this paper evaluates and optimizes the design of the system,then presents the optimal solar floor heating system.It is imperative to evaluate the solar energy saving efficient except for the solar heating fraction.

Annual energy consumption composition of a typical residential building has been investigated through the statistical analysis of different energy annual consumption of a residential area,which provides reference and basic data for mastering annual energy consumption of residential building comprehensively,discussing energy saving potential and approaches of residential building in Beijing.

Taking some sandwich system as an example, the authors analyze and calculate global mechanical status under surrounding temperature and sunshine condition in winter and summer in Beijing area and mainly think about influence of deadweight stress and temperature stress on global mechanical status. By analyzing,it is found out that the key factor,which can influence on stability and durability of this system,is temperature stress on interface and mortar layer,which horizontally parallels to wall. Also the current standards are lack of the mechanical properties indexes of tension and compression stress on external wall external insulation system,which need to be paid attention for the relevant departments.

未保温的出挑结构引起结构墙体出现裂缝,严重影响了外墙外保温体系的稳定以及基层墙体的使用寿命.针对这一常见外墙外保温的工程灾害,利用ANSYS工程计算软件模拟和分析未保温出挑结构的温度场和温度应力,从温度场和温度应力两个方面阐述裂缝产生的机理和原因.

Chinese urban construction is in its rush hour now.Building energy consumption has accounted for 20% to 30% of the general commodity consumption in China,and residential energy consumption has accounted for about 60% of the building energy consumption.Nonetheless,the energy consumption data about residential buildings in Beijing is lacking.In order to understand the situation of residential energy consumption generally,a questionnaire survey on the condition of energy consumption was made in twenty-three residence communities and two markets in seven districts in Beijing from January to May,2009.The total number of questionnaires is 3000,and the number of valid questionnaires is 1692.The questionnaire mainly includes construction condition,building envelope,air-conditioning,life habits,etc.14% of the investigated buildings aren't energy-saving buildings,and 9% of the investigated buildings' windows are made of iron.Therefore,the residential building envelope should be made more energy-saving.Furthermore,64% of the residents own one redundant air-conditioner and 99% of the residents set the cooling temperature of air-conditioning colder than at 29℃,which is advocated by the Beijing government.Besides,it shows that the energy consumption per unit residential area in Beijing is 38kWh/(m2·y),which is higher than the level of Chinese towns and cities,and is two-thirds of USA.In addition,some effective energy conservation behaviors have not aroused enough attention,and we should strengthen the publicity of energy-saving behaviors.