超高层建筑平面控制网竖向传递实践与研究     

赵小阳  刘业光 《测绘信息与工程》2010,35(4):28-29

分析了超高层建筑平面控制网的建立及竖向传递的方法,介绍了数字正垂在测定超高层建筑倾斜偏差的具体应用,实现了用全站仪法和GPS法来检核控制网竖向传递的精度。  相似文献   

北京城市下垫面对雾影响的数值模拟研究   总被引：2，自引：0，他引：2       下载免费PDF全文

张亦洲  苗世光  李青春  戴永久 《地球物理学报》2017,60(1):22-36

为了探究北京城市下垫面对雾天气过程的影响,为北京地区雾数值预报水平的提高提供理论基础和科学依据,选取2011年10月29日北京地区雾天个例进行了数值模拟试验,通过对WRF/Noah/UCM模式系统中城市冠层参数的调整,显著改善了模式对此次雾天气过程的模拟效果.使用参数调整后的模式系统通过敏感性试验分析研究了北京城市下垫面对雾发生、发展和消散过程的影响.结果表明:参数调整后的WRF/Noah/UCM模式系统能够与实际观测较相符地模拟此次发生在北京地区的雾天气过程,北京城市下垫面主要通过对温度的改变对雾的形成、发展和消散产生显著影响,使雾不易在城市及其附近形成和发展,延后城市地区雾的形成,但城市的存在也使得城市地区及其附近雾不易消散,相较于没有城市时消散时间延后.  相似文献   

兰州城市建筑的空间分布   总被引：1，自引：0，他引：1  

杨永春 《世界地理研究》2008,17(1):39-46

利用高精度卫星影象和大规模实地调查方法获取数据,采用GIS手段、景观生态学和数理统计等方法,利用建筑占地面积和建筑面积等指标分别研究了兰州市各区、功能区、各组团、各圈层现状建筑的空间分布与组合,以及城市资产、土地强度的空间变化规律。结果表明：住宅、工业、商务三类建筑是兰州市建筑的绝对核心类型,空间分布均衡而广泛,且工业建筑向外围迁移过程中存在全域分散化特征：兰州市各区建筑用途复杂程度、多样性和均匀性由中心到外围大致逐步降低,优势度逐渐增加,组团分布特征显著而强烈;建筑更新具有明显的全域化和快速推进特征;建筑用途空间组合、建筑容积率由中心到外围的空间波动性较为显著：建筑用途多样性、建筑容积率等指标高或低的“插花”分布现象相当显著;住宅、工业建筑更新与空间分化是城市建筑更新、建筑用途空间分化与组合及其变迁的核心动力因素,单位制模式的影响依旧强烈和深刻。  相似文献   

基于国外城市群发展经验的哈大齐工业走廊的竞争策略   总被引：2，自引：0，他引：2  

陶涛  臧淑英  冯秀梅 《世界地理研究》2008,27(3):92-99

哈尔滨、大庆、齐齐哈尔三市在黑龙江省老工业基地中占有重要地位,建设哈大齐工业走廊是黑龙江省做出的一项重大决策,是充分利用本省优势,节约土地资源、改善生态环境、实现可持续发展的战略举措。大力发展哈大齐工业走廊城市群将对东北老工业基地的振兴起到重要作用。本文通过借鉴国外城市群发展的成功经验以及对哈大齐工业走廊发展中的症候的分析,提出了这一新兴城市群快速持续发展的竞争对策。  相似文献   

Dynamic responses of two buildings connected by viscoelastic dampers under bidirectional earthquake excitations   总被引：1，自引：1，他引：0  

Z.D. Yang  Eddie S.S. Lam 《地震工程与工程振动(英文版)》2014,13(1):137-150

In this study,dynamic responses of two buildings connected by viscoelastic dampers under bidirectional excitations are extensively investigated.The two buildings are a 10-story building and a 16-story building,with the shorter building on the left.Viscoelastic dampers are installed at all fl oors of the shorter building.Equations of motion are formulated using a fractional derivative model to represent the viscoelastic dampers.Three cases are considered with mass eccentricities at 0,10% and-10% with respect to the dimensions of the buildings.The responses of the buildings are numerically predicted at different damper properties.The simulation results indicated that the maximum horizontal responses of the buildings without eccentricities are signifi cantly mitigated.However,torsional effects are adversely increased.For asymmetric buildings,the effectiveness of the connecting dampers is affected by building eccentricities.As a result,mass eccentricities must be taken into account in damper selection.When compared with vibrations induced by unidirectional excitations,bidirectional excitations can increase the responses of coupled asymmetric buildings.In addition,installing dampers only at the top fl oor of the shorter building may cause a sudden change in lateral stiffness of the taller building.Consequently,the story shear envelopes of the taller building are changed.  相似文献   

Response reduction factor of irregular RC buildings in Kathmandu valley     

Hemchandra Chaulagain  Hugo Rodrigues  Enrico Spacone  Ramesh Guragain  Radhakrishna Mallik  Humberto Varum 《地震工程与工程振动(英文版)》2014,13(3):455-470

Most current seismic design includes the nonlinear response of a structure through a response reduction factor(R). This allows the designer to use a linear elastic force-based approach while accounting for nonlinear behavior and deformation limits. In fact, the response reduction factor is used in modern seismic codes to scale down the elastic response of a structure. This study focuses on estimating the actual ‘R' value for engineered design/construction of reinforced concrete(RC) buildings in Kathmandu valley. The ductility and overstrength of representative RC buildings in Kathmandu are investigated. Nonlinear pushover analysis was performed on structural models in order to evaluate the seismic performance of buildings. Twelve representative engineered irregular buildings with a variety of characteristics located in the Kathmandu valley were selected and studied. Furthermore, the effects of overstrength on the ductility factor, beam column capacity ratio on the building ductility, and load path on the response reduction factor, are examined. Finally, the results are further analyzed and compared with different structural parameters of the buildings.  相似文献   

Extended consecutive modal pushover procedure for estimating seismic responses of one-way asymmetric plan tall buildings considering soil-structure interaction     

Mohammad Hadikhan Tehrani  Faramarz Khoshnoudian 《地震工程与工程振动(英文版)》2014,13(3):487-507

Performance based design becomes an effective method for estimating seismic demands of buildings. In asymmetric plan tall building the effects of higher modes and torsion are crucial. The consecutive modal pushover (CMP) procedure is one of the procedures that consider these effects. Also in previous studies the influence of soil-structure interaction (SSI) in pushover analysis is ignored. In this paper the CMP procedure is modified for one-way asymmetric plan mid and high-rise buildings considering SSI. The extended CMP (ECMP) procedure is proposed in order to overcome some limitations of the CMP procedure. In this regard, 10, 15 and 20 story buildings with asymmetric plan are studied considering SSI assuming three different soil conditions. Using nonlinear response history analysis under a set of bidirectional ground motion; the exact responses of these buildings are calculated. Then the ECMP procedure is evaluated by comparing the results of this procedure with nonlinear time history results as an exact solution as well as the modal pushover analysis procedure and FEMA 356 load patterns. The results demonstrate the accuracy of the ECMP procedure.  相似文献   

Plasma‐Based Indoor Air Cleaning Technologies: The State of the Art‐Review          下载免费PDF全文

Mitra Bahri  Fariborz Haghighat 《洁净——土壤、空气、水》2014,42(12):1667-1680

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Response of Planktonic and Benthic Microbial Community to Urban Pollution from Sewage Discharge in Jilin Reach of the Second Songhua River,China          下载免费PDF全文

Shanshan Lin  Ying Wang  Jifang Lin  Chengshi Quan 《洁净——土壤、空气、水》2014,42(10):1376-1383

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武汉城市群交通运输体系与城镇空间扩展关联分析   总被引：1，自引：0，他引：1  

关兴良  蔺雪芹  胡仕林  鲁莎莎 《地理科学进展》2014,33(5):702-712

交通运输体系与城镇空间扩展的关联分析是揭示交通运输与经济增长作用关系的重要切入点。采用等时线叠置法和指标分区法,分析了武汉城市群交通可达性及交通优势度与城镇空间扩展的时空格局、关联特征及其作用机理。研究表明,交通运输体系与城镇空间扩展具有内在联系,呈现出互动耦合、协同演进格局。从作用机理来看,交通运输体系通过直接效应、外部效应和乘数效应对城镇空间扩展起着重要的支撑和推动作用;城镇空间扩展在“量”和“质”上对交通运输提出了新要求,刺激并保障了交通运输体系的发展,两者相互反馈、相互依赖。从政策启示来看,交通运输体系的空间不均衡是造成区域经济发展水平差异的重要因素,制定差别化的交通运输发展战略和完善一体化的交通运输体系是加快区域经济增长和缩小地区差距的重要途径。  相似文献