Dynamic pressures on a pair of rigid walls retaining poroelastic soil     

D. D. Theodorakopoulos   《Soil Dynamics and Earthquake Engineering》2003,23(1):41-51

This work deals with the evaluation of the dynamic pressures and the associated forces on a pair of rigid vertical cantilever walls retaining a uniform, fully saturated poroelastic layer of soil. Hysteretic damping in the soil skeleton may also be present. Wall pressures and forces are induced by horizontal ground shaking harmonically varying with time and spatially invariant. The problem is solved analytically under conditions of plane strain. The governing partial differential equations of motion, after separation of variables and the simplifying assumptions of zero vertical normal stresses and zero horizontal variation of vertical displacements, reduce to a system of two ordinary differential equations for the amplitudes of the solid skeleton horizontal displacement and the pore water pressure, which are easily solved. The parameters examined include the ratio of the distance between walls to the height of the retained soil material and the soil material properties such as porosity, permeability and damping. The comprehensive numerical data presented indicate that the displacements, wall pressures and resultant forces are highly dependent on the distance between the walls for any values of porosity and permeability.  相似文献   

山西省地震局专业技术人员队伍结构现状分析与培养对策   总被引：1，自引：0，他引：1  

李俊拴 《山西地震》2002,(3):38-42

对山西省地震局专业技术人员的知识结构、人才结构现状进行了分析 ,指出目前专业技术人员队伍存在的主要问题是整体文化程度偏低 ,专业结构不太合理 ,地质、测量和物理探矿等专业人才相对缺乏 ,整体科技能力有待加强等。论述了人才培养的重要性和紧迫性 ,提出了专业技术人员队伍结构优化和人才培养的对策  相似文献   

设计企业电子资料管理与企业知识管理初探     

沈振一  沙左帼 《中国勘察设计》2008,(3):74-76

本文阐述了设计企业对电子资料管理平台建设的认识和需求,以及电子资料库的建设和利用给企业知识积累带来的积极应用效果。  相似文献   

陕北能源化工基地潜水易污性评价   总被引：4，自引：0，他引：4  

贺帅军  李云锋  张茂省  党学亚  李小等 《地质通报》2008,27(8):1186-1191

随着陕北能源化工基地的建设和发展,地下水污染问题日益突出。为了预防基地地下水的污染,保护水资源,依据陕北能源化工基地地下水勘查、地下水污染调查、野外包气带原位污水垂直入渗、水平运移试验等基础资料,选取潜水位埋深（D）、降雨入渗补给量（R）、含水层岩性（A）、土壤类型（S）、地形坡度（T）、包气带介质（I）和含水层渗透系数（C）7个指标,运用DRASTIC指标叠加法,建立了陕北能源化工基地潜水易污性评价指标体系,对陕北能源化工基地潜水进行了易污性评。依据评价结果,将研究区潜水区划分为易污性高、中、低3个区,并针对3个区提出了相应的防污建议。  相似文献   

数码航摄(DMC)像控布设方案研究   总被引：2，自引：1，他引：1  

朱士才  树华  邹学忠  徐晓峰 《现代测绘》2008,31(6)

利用1∶3500、1∶6000、1∶20000三种比例尺的DMC航摄资料,在航线数不变的条件下分别采用每隔4、6、8、10、16条基线进行像控点布设,在立体测图仪上加密、纠正、测图,提取地物点其坐标与外业检测成果比较,检验其对1∶500、1∶1000、1∶5000三种比例尺成图精度的影响。  相似文献   

镇江市基础地理信息系统的设计与实现   总被引：1，自引：0，他引：1  

刘波  徐迪峰 《现代测绘》2008,31(1):41-43

基础地理信息系统在城市管理中的作用十分重要,本文主要介绍了镇江市基础地理信息系统的框架设计、功能体系,以及实现的关键技术,为建设城市基础地理信息系统提供借鉴参考.  相似文献   

振动沉管灌注桩施工及事故处理     

李荣再 《云南地质》2007,26(2):264-269

简要介绍振动沉管灌注桩施工方法,以及质量事故控制和处理措施。  相似文献   

鄂尔多斯盆地西南缘镇泾油田6-2沉积相研究     

丁晓琪张哨楠  王少飞刘岩 《新疆地质》2007,25(1):105-110

延长组长6-2是鄂尔多斯盆地西南缘镇泾油田的一个重要勘探层位．通过岩心观察、测井资料、薄片研究、粒度分析，对镇泾油田长6-2沉积微相进行了深入研究．认为该区长6-2由一个完整的中期基准面旋回组成，水下分流河道主要发育在中期基准面缓慢上升初期和快速下降阶段，由于水下分流河道的强烈侵蚀作用，河口坝砂体不发育．中期基准面缓慢上升初期的河道具有深而窄的特点，砂体横向变化快，勘探难度大，而与之相对的是中期基准面快速下降阶段，水下分流河道具有厚而广的特点，为本区最为有利的勘探目的层．通过对不同可容空间下水下分流河道砂体厚度与河道宽度的研究，发现其具有很好的相关性，得出该区的砂体厚度与河道宽度的经验公式，为下一步勘探开发提供了强有力的理论依据。  相似文献   

Relational networks of knowledge production in transnational law firms   总被引：1，自引：0，他引：1  

James R. Faulconbridge 《Geoforum》2007,38(5):925-940

For geographers, debates surrounding the knowledge economy have reinvigorated interest in the geographies of learning and knowledge production. Particularly topical are discussions of the possibility of spatially stretched (global) learning, something especially relevant to professional service firms where the production and management of knowledge across transnational organizational networks is essential. Taking this as its starting point, the paper explores the way knowledge is produced and circulated in transnational legal professional service firms. Drawing on the ideas of relational economic geography to analyse original empirical material, it highlights the way relational networks are socially constructed to allow learning to be stretched across space. The paper then goes on to identify the ‘politics’ of inclusion in these networks and the exclusivity of membership. It also highlights the geographies of power that influence the nature and effect of the knowledge produced and circulated. It does this by examining the role of relational knowledge networks in the ‘Americanization’ of legal practice in Europe and the impacts of such changes on national institutional and regulatory contexts. It is, therefore, argued that transnational corporate networks need to be viewed as heterogeneous and ‘embedded spaces of social practice’. It is shown that studying the actors and their interactions across relational networks is vital to fully understand how global relational forms are constructed and to understand their structuring effects on the global economy.  相似文献   

Catchment contrasts: Comparing young people’s experiences and knowledge of a river environment     

Ruth Panelli  Gretchen Robertson 《Geoforum》2006,37(4):455-472

Early geographies focussed on children have recorded their environmental and spatial perceptions. Contemporary theoretical and methodological advances in, and beyond, children’s geographies have supported a more complex engagement with environmental topics. Complementing this work, a study of young people’s experience and knowledge of a river in southern New Zealand is presented. Data were gathered from four contrasting locations within one, 5650 sq. km, catchment, employing child-oriented, multi-method approaches. Data analysis confirms existing literature highlighting how young people are competent knowledge producers with varying experiences and understandings. Some of this variation can be appreciated by focussing on factors of age, gender and catchment location. Together these findings are relevant to both academic and planning circles and implications for young people’s participation in catchment management are noted as a key area for further development of work of this kind.  相似文献