由多个地震震源机制解求福建东南沿海地区平均应力场     

钟继茂  程万正 《福建地震》2006,(Z2)

基于震源断层面的空间取向和滑动方向,写出力轴张量在地理坐标系中的表达式,进而给出计算平均力轴张量及主值的方法,即通过求解相应的本征方程得到。对使用多个震源机制解中T,B,P轴参数计算平均应力场的正确性,以许忠淮用滑动方向拟合法反演富蕴、唐山地区平均应力场数据进行计算和验证。选择具有地震构造意义地块或地震带内大量地震的震源机制解研究区域平均应力场。根据福建东南沿海地区47次主要地震的震源机制解,给出了该区应力张量的定量分析结果。该方法物理意义明确,使由大量地震震源机制解资料分析构造应力场的方法走向定量化,并为定量探索区域应力场的整体动态变化成为可能。  相似文献   

碳纤维布增强钢筋混凝土柱延性性能的评估与分析   总被引：2，自引：0，他引：2  

赵彤  刘明学  谢剑 《地震工程与工程振动》2003,23(4):117-123

在试验研究的基础上，对碳纤维布提高钢筋混凝土柱延性的机理进行了分析，确定了碳纤维布用量、轴压比、剪跨比、矩形截面柱转角部位的形状等试验因素对碳纤维布加固钢筋混凝土柱延性的影响规律。在此基础上，重点对碳纤维布加固钢筋混凝土柱延性性能的评估与分析方法进行了研究，提出了碳纤维布加固矩形截面钢筋混凝土柱位移延性比的理论计算方法和简化计算公式。计算结果与试验数据能较好地吻合。工程技术人员可以应用上述方法，对碳纤维布增强钢筋混凝土柱延性性能进行合理的评估与分析。  相似文献   

地下排水与观测廊道加固方案的现场试验论证     

高作平  陈明祥  周剑波 《岩土力学》2003,(Z2)

华东天荒坪抽水蓄能电站上水库库底的地下排水与观测廊道为城门洞型,拱体为预制混凝土,边墙与底板现浇。运行期间发现廊道拱顶沿纵向开裂。电厂曾采用外加钢结构支撑混凝土拱顶的方案进行了加固处理,但裂缝开裂并没有得到有效控制。为弄清拱顶开裂原因,提出有效的改造加固方案,为此,进行了现场试验,结果表明:预制混凝土拱脚相对现浇边墙发生向外侧的滑动,是导致开裂的主要原因,因此,阻止其相对滑动,是加固处理的关键。  相似文献   

Determination of mechanical properties of traditional masonry walls in dwellings of Faial Island,Azores     

Aníbal Costa 《地震工程与结构动力学》2002,31(7):1361-1382

The determination of mechanical properties of masonry walls is a fundamental pre‐requisite for the characterization of the seismic response of traditional buildings, which helps on the definition of adequate rehabilitation and strengthening procedures. This paper presents a testing campaign carried out in the Cedros region of Faial Island, Azores, hit by the July 98 earthquake, aiming at the determination of physical and mechanical properties of stone masonry walls, namely the mass density and Young's modulus. The paper describes the developed testing techniques as a contribution to the study and the preservation of traditional masonry buildings. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

Changes in the Structure of a Coastal Fish Assemblage Exploited by a Small Scale Gillnet Fishery During an El Niño–La Niña Event     

E. Godínez-Domínguez  J. Rojo-Vzquez  V. Galvn-Pia  B. Aguilar-Palomino 《Estuarine, Coastal and Shelf Science》2000,51(6):773

During 1998 an experimental gillnet fishing survey was carried out in a Mexican Central Pacific inshore zone. One-hundred and thirty fish species belonging to 51 families and 18 orders were identified. The most abundant species wereMicrolepidotus brevipinnis (29·0% of the total abundance) and Caranx caninus (19·2%), followed by C. caballus (6·3%), Kyphosus analogus (4·3%) and C. sexfasciatus (3·4%). Thermal SST anomalies showed the existence of two periods. The first, from January to April with positive anomalies, defines the end of an El Niño episode. The second period, from May to December, constitutes the beginning of the La Niña episode. The typical seasonality in a non-anomalous year continued for a large percentage of the inshore fish community, and the effects of the anomalous event consisted of changes in seasonality of occurrence in some individual species and the unusual abundance of some uncommon species. The species richness was higher during the El Niño–La Niña event than in a non-anomalous year, and therefore the event could be considered an interannual environmental mechanism that favours fish diversity in inshore waters.  相似文献   

我国沿海地区生态城市建设评价   总被引：17，自引：2，他引：15  

宋冬梅  肖笃宁  申元村 《地理科学进展》2004,23(4):80-86

本文从城市生态系统的结构、功能和协调度三个方面构建了生态城市的指标体系,提出了生态城市的评价方法,并选取沿海16个城市进行城市生态化建设的综合评价与比较分析。采用适合生态城市建设的数学模型对这些城市的复合生态系统进行定量分析,其中指标涉及人口指标、生态环境指标、经济指标与社会指标4个方面,构建3个一级指标,10个二级指标,25个三级指标。得出了16个沿海城市生态化水平的比较结果,因之深圳在城市结构、城市功能方面明显高于其它城市,其生态化综合水平位居首位,其值超过标准值达到了1.19,营口市在工业废水达标率、环境噪声达标率、人均生活用水、人均国民生产总值与失业率方面得分最低是导致其生态化综合水平最低的主要原因。16市在城市环境方面得分普遍较低,表明大气质量与环境噪声是限制这些城市生态建设的主要因素。  相似文献   

快速加固吹填泥浆的试验研究与分析   总被引：3，自引：0，他引：3  

刘娉慧  王清  石丙飞  蒋剑 《岩土力学》2005,26(12):2023-2026

为了研究利用外掺剂加快吹填泥浆的沉积落淤问题,找到能够使吹填土尽快地从泥浆状态转变为具有一定承载力的地基方法,将吹填泥浆中分别加入水泥、生石灰、水泥和生石灰混合剂,通过沉降柱试验模拟了外掺剂作用下吹填泥浆的落淤、自重固结、预压下强度增长等过程,并从粒度成分、矿物成分、和微观结构方面进行了加固机理的分析,从而在吹填的同时对吹填泥浆进行加固。结合处理前后相关试验结果的对比分析发现,外掺剂能够加速吹填泥浆的落淤、固结及强度增长。  相似文献   

真空和堆载两种预压法的室内试验研究   总被引：2，自引：0，他引：2  

吴桂芬  高玉峰  魏代现  刘汉龙 《岩土力学》2005,26(Z1):95-98

通过室内试验模拟真空预压法和堆载预压法加固不同深度的土体,对两种预压法下土体前后的物理力学性质指标、土体的沉降量、排水量等进行了分析,认为两种方法均能使土体的物理力学性质改善,就渗透性而言,真空预压优于堆载预压,但就压缩性而言,堆载预压优于真空预压;堆载预压下试样的轴向位移远大于真空预压下的轴向位移,且比真空预压下的沉降收敛慢;真空预压下的排水量大约是堆载预压下排水量的1.8倍;在真空预压和堆载预压下,浅层土体的排水量均大于深层土体的排水量。  相似文献   

我国农村房屋抗震与加固的研究及进展     

杨仕升  王永幸  谢开仲 《华南地震》2011,31(3):140-149

我国大多数破坏性地震都发生在农村,通过分析我国农村房屋建筑的主要结构形式、震害特征及其建造特点,发现缺乏设防意识、缺乏抗震技术和经济条件差是农房“小震致灾、大震大灾”的主要原因.通过对既有的结构抗震、鉴定、加固、隔震技术的综述,发现目前我国仍比较缺乏适合农村房屋的抗震及加固技术.最后对农村房屋抗震与加固方法提出建议,展...  相似文献   

In situ cyclic tests on existing stone masonry walls and strengthening solutions     

Alexandre A. Costa  António Arêde  Aníbal Costa  Carlos Sousa Oliveira 《地震工程与结构动力学》2011,40(4):449-471

The present work reports on an in situ experimental test campaign carried out on abandoned traditional masonry houses after the 9th July 1998 earthquake that seriously hit the Faial island of Azores. For the testing purposes, an experimental test setup was developed based on a self‐equilibrated scheme, which is herein described reporting on the advantages and drawbacks of this in situ test setup. Five specimens were tested aiming at characterizing the out‐of‐plane behavior of stone masonry walls and strengthening solutions recommended for post‐earthquake interventions. A detailed comparison between solutions' efficiency is presented including a cost vs benefit analysis. In order to assess the efficiency of the developed test setup for other applications on stone masonry walls, an in‐plane test on an existing URM panel is also presented. Several related issues are discussed, namely the advantages of dealing with the real boundary conditions and the capacity of providing valuable information of the response, as well as a detailed analysis of the obtained results. The authors believe that this work provides an increase in knowledge on the seismic behavior of the existing masonry constructions, resulting from the development of an in situ test setup and the efficiency quantification of strengthening solutions. Therefore, the work is thought to positively contribute for the preservation of architectural heritage and for its seismic vulnerability reduction. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献