试论北京“山水城市”特色的继承与发展

试论北京“山水城市”特色的继承与发展施卫良“山水城市”是人与自然相互和谐结合的城市观，它是中国传统风水理论的体现，反映了传统的“天人合一”思想，其核心在于城市的人工环境与自然环境的完美融合和协调。“山水城市”提供给城市的不仅是山和水，更主要的是绿色环...     

专家评判北京城

2003年6月19日,专家学者云集在世界著名建筑大师贝聿铭设计的北京香山饭店,其乐融融,其心沉沉,其言凿凿。银丝如雪的老专家,抚今追昔,感慨万端,有呼吁,有遗憾,有忠告,有秘方;血气方刚的年青专家,慷慨激昂,未雨绸缪,有呐喊,有忧虑,有良策,有绝招。新奇特征与个性化追求 ●清华大学建筑设计研究院总建筑师、建筑设计大师 胡绍学:首都近年来在城市规划、环境保护、市政建设重大项目等方面均已取得了令人瞩目的巨大成绩。我们应大力提倡求实、求真的作风。建筑最本质的东西,是使用功能和形式完美的统一,为追求某种时髦建筑形式而不惜代价不…     

再论继承与创新——从历史名城保护谈开去

规划师要重视城市文化史的研究：知识社会是实现文化价值的社会。任何物品或商品都包含创意和物质两种投入;而且随着知识经济的发展作为创意投入的比重增加,超过物质投入的价值。故信息社会的核心是以信息技术支撑的文化内。城市规划是对城市空间资源进行合理配置和科学利用。但是城市空间资源具有非常鲜明的时间特性,时空不可分割。尤其是具有几千年历史文明的古国每一部分城市空间都淀积看悠久的文化。体现出城市空间独有的文化价值、人文资源和亘古的魁力。在城市的形体物质空间承载着千年创意,它们是价值远远超过物质形体的知识和智…     

北京古都风貌保护初探—从南北长街规划谈起

北京古都风貌保护初探──从南北长街规划谈起郝霞北京是一个具有悠久历史和灿烂文化的古都。如何保护好北京的古都风貌，是城市规划工作者的一项迫切而又艰巨的任务。１９８９年８月，为配合＂北京市确定第一批２４片历史文化保护区＂的工作，我们编制了南长街和北长街（...     

探求北京古都风貌保护"死结"的经济解

北京是世界最伟大的历史古都之一,是距今40万～50万年前"北京人"的聚居地,有3000多年的建城史、851年的建都史,是中国古代都市设计的无比杰作,是中国古代都城的最后结晶,是千百年来中华民族心血所凝聚成的灿烂瑰宝.保护北京古都风貌具有深远的历史意义和重大的国际意义.     

保护历史精华发展现代城市

保护历史精华发展现代城市北京市副市长汪光焘主席先生、各位代表、各位来宾：我们北京市的代表很高兴能参加“中国──欧洲历史城市的保护和发展”国际会议，使我们有机会向欧洲和我国其它兄弟城市学习这方面的成功经验。历史城市的保护和发展，在当代已成为一个世界性的...     

注重历史与现实的结合搞好历史文化名城保护

注重历史与现实的结合搞好历史文化名城保护单士元，候仁之，张开济［编者按］如何处理好保护与发展的关系，继承历史传统，建设现代文明城市，是历史文化名城保护与建设中的关键问题。日前，本刊记者分别采访了著名古建专家单士元先生、著名地理学家侯仁之先生和著名设计...     

北京古树衰弱原因分析

古树是北京悠久历史的见证．古树名木和长城故宫一样是十分珍贵的国之瑰宝,更是古都风貌的代表．它同时是北京灿烂文化的一部分。北京的名松古木很多,大部分分布在郊外的寺庙中,保护好这些古树是我们这代人的历史使命。     

Soil-pipe-atmosphere interaction under field conditions

Bulletin of Engineering Geology and the Environment - Unsaturated clay deposits swell and shrink as a result of seasonal variations in climatic conditions and affect the performance of underground...     

盾构隧道叠交施工引起的土层位移场分布规律

考虑盾构隧道叠交施工之间的相互影响,应用边界单元法对相邻隧道开挖过程中的三种典型叠交位置关系,引起的地层位移场分布规律及相互影响进行分析。分析结果表明:单条隧道开挖引起的地表最大沉降值出现在隧道轴线的正上方,而两左右或上下相邻隧道开挖的地表及土层内部的最大沉降值则出现在两隧道的纵轴线之间,且偏向上方埋深较浅的隧道。隧道开挖引起的地层深层与浅层变形趋势是一致的,但在两隧道轴线上方深层土体的沉降要远比浅层土体大。叠交隧道的埋深及其相对空间位置关系对土层的位移场有较大的影响。     

斜坡地形桩土相互作用下初始地应力场的处理

考虑桩土接触行为的影响,采用大型有限元软件ANSYS进行了斜坡地形的初始应力有限元模拟,算例表明该方法可以很好的消除初始位移场,从而较好的保留初始应力场,为研究各种岩土问题提供了一种处理复杂初始应力场的有效方法。     

浅谈现场总线系统的现场仪表

结合现场总线系统的发展，分析了现场总线智能仪表与控制设备降低成本的必要性，研究了不可能短期内完全实现现场设备网络化的原因，探讨了现场总线的应用前景，评价了现场总线的经济效益，以促进现场总线系统的发展。     

Spatial interaction modelling

Spatial interaction (SI) is the process whereby entities at different points in physical space make contacts, demand/supply decisions or locational choices. The entities can be individuals or firms and the choices can include housing, jobs, production quantities, exports, imports, face-to-face contacts, schools, retail centres and activity centres. The first SI models can be grouped under the generic heading gravity models. Their main characteristic is that they model the behaviour of demand or supply segments, rather than that of individuals and firms. This article traces the development of these models from their inception in the early part of the twentieth century to the present. The key advances include the replacement of the gravity analogy by the more general concepts of entropy or information theory, a statistical framework commonly used in physics. With the arrival of the regional science paradigm over 50 years ago, a key challenge has been to broaden these models compared to those arising in spatial economics, thus arriving at a more inclusive probabilistic framework. These efforts are discussed here, as well as inclusion of geographical advances, embracing activities as generators of travel, time-geography, recognition of spatial interdependencies, and use of neuro-computing principles.JEL Classification: C190, C450, C610, R00     

Spatial interaction modelling

Abstract. Spatial interaction (SI) is the process whereby entities at different points in physical space make contacts, demand/supply decisions or locational choices. The entities can be individuals or firms and the choices can include housing, jobs, production quantities, exports, imports, face-to-face contacts, schools, retail centres and activity centres. The first SI models can be grouped under the generic heading gravity models. Their main characteristic is that they model the behaviour of demand or supply segments, rather than that of individuals and firms. This article traces the development of these models from their inception in the early part of the twentieth century to the present. The key advances include the replacement of the gravity analogy by the more general concepts of entropy or information theory, a statistical framework commonly used in physics. With the arrival of the regional science paradigm over 50 years ago, a key challenge has been to broaden these models compared to those arising in spatial economics, thus arriving at a more inclusive probabilistic framework. These efforts are discussed here, as well as inclusion of geographical advances, embracing activities as generators of travel, time-geography, recognition of spatial interdependencies, and use of neuro-computing principles.     

Laboratory determination of clay-geotextile interaction

Current design regulations preclude the usage of cohesive backfills in reinforced soil structures regardless of whether the reinforcement is metallic or polymer fabric. The main reasons for this are: firstly, cohesive materials can be expansive; and secondly, the maximum bond strength between the reinforcement and the clay is normally not expected to be more than the undrained strength of the clay, giving no advantage. However, low-plasticity (so-called semi-cohesive) soils are not expansive and could be used in reinforced soil structures provided the reinforcement can give an increase in strength. A large number of shearbox and pull-out tests have been carried out to investigate which are the major factors governing the clay-geotextile interaction in both undrained and drained conditions. Woven and non-woven fabrics and meshes were used in the tests. The results have shown that the shearing strength of clay can be increased by properly selected geotextile reinforcement in both undrained (short-term) and drained (long-term) loading. It has been also shown that the pull-out resistance of the geotextile reinforcement is essentially proportional to the normal stress and for high transmissivity geotextiles or for geogrids it is limited by the tensile strength and relaxation of the material. The low transmissivity however is also a factor obstructing the development of high pull-out resistance in undrained conditions. The results indicate that geotextile reinforced cohesive backfill might be a viable alternative in reinforced soil structures if good-quality granular backfill material is not readily available.     

土与结构相互作用理论

论述了土与结构相互作用理论的研究方法及其计算理论--整体数值分析法、子结构法、集中参数法.     

Log-linear modelling of spatial interaction

The research reported in this paper is part of a larger research effort to develop a methodology for estimating spatial interaction (migration) flows. The first section of the paper summarises the equivalences between the log-linear model and conventional spatial interaction models. It is shown under what conditions the values of the balancing factors of the gravity model coincide with the parameter values of the loglinear model. The second section focuses on theanalysis of (known) spatial interaction flows. The effects associated with the region of origin, region of destination and spatial separation are identified and quantified. A ‘distance effect’ is derived from the flow matrix. A measure of accessibility is developed and compared with accessibility measures derived from different forms of distance functions. The third section deals with theestimation of spatial interaction flows. It is shown how the quality of the estimates (and hence the model performance) can be improved by efficiently adding information. This is particularly relevant in the estimation of disaggregated spatial interaction flows.