不同开挖步距对地铁深基坑影响的研究

高速发展的城市,建筑物密集建设,使得城市地下空间开挖对临近建筑影响越来越大,所以研究不同的开挖卸荷步距对深基坑的影响有较大的意义和实用性。对地铁深基坑开挖过程进行模拟分析,通过设置不同的开挖步距和不同的支撑,证明了不同开挖步距对基坑及周边土体有较大影响。     

上海地区深基坑施工对周围历史建筑的影响

随着我国城市化进程的推进,城市中历史建筑的保护早已被提上议程.于是城市中深基坑开挖对周围历史建筑的影响分析作为一个新课题,越来越受到人们的重视.结合徐家汇圣母院受周围深基坑开挖影响的工程实例,探讨了上海地区深基坑开挖对周围历史建筑的各种影响因素及减小影响的施工方法,并对历史建筑的保护提出了具体建议,评价了其合理性和科学...     

滨海城市深基坑开挖变形特征及防治对策

本文在对滨海城市深基坑开挖工程现状分析的基础上，对深基坑开挖变形的类型，特点与规律进行了较详细的研究，并对深基坑开挖变形的防治对策进行了探     

滨海城市深基坑开挖变形特征及防治对策

本文在对滨海城市深基坑开挖工程现状分析的基础上，对深基坑开挖变形的类型，拈民规律进行了较详细的研究，并对深基坑开挖变形的防治对策进行了探讨 。     

刍议深基坑开挖支护工程的特点及现状

近年来,城市中的建筑密度随着城市现代化的推进而增大,随着高层建筑的不断兴建,深基坑开挖的问题也越来越多.对深基坑开挖及对邻近的建筑、道路设施的影响也是工程师们所关注的重点,开挖的深度越来越深,开挖的环境日益复杂,设计及施工人员经常遇到新的问题及新的挑战,从而使基坑工程的成功率降低.本文通过对深基坑支护工程的特点和深基坑开挖的现状来分析,并提出一些个人的看法和建议,仅供同行参考.     

逆作法在深基坑土方开挖施工中的应用

随着当前人们生活水平的不断提高,人们对城市空间的需求也逐渐加大。当前我国的城市空间较小,根本无法满足人们逐渐增长的建筑空间的需要。为了解决这种情况,相关部门开始实行深基坑土方开挖,通过对城市的地下面积进行深基坑土方开挖增强对城市空间的利用率。本文就采取逆作法实现深基坑土方开挖中的相关问题进行研究,提出解决办法,现研究结果如下。     

深基坑开挖对周边环境的影响及防治措施

随着城市建设的快速发展,对基坑开挖的深度的要求日益增加,深基坑的开挖成为建筑物的必需.然而深基坑由于其深度问题,在施工中会对其他的建筑物等产生影响,从而成为抵制工程中的一个复杂问题.施工方对深基坑的关注以及工作时的态度成为负面影响减低的要点.本文主要结合深基坑实例,针对深基坑开挖引起的一些问题进行分析,并提出了有效的防治措施.     

深大基坑开挖对临近车站底板上浮的影响

城市地下空间的发展,经常会碰到在地铁工程周边进行地下工程施工的难题,地铁周边深基坑开挖将对地铁工程产生影响.本文结合上海市轨道交通11号线临港新城站的实例,建立有限元计算模型,分析了三种深基坑开挖工况对邻近地铁车站底板上浮的影响,很好的指导了该工程的施工,同时为今后地铁周边深基坑开挖提供参考.     

合肥地铁深基坑施工对周围建筑物的影响

通过对基坑周围建筑物的沉降监测,研究深基坑开挖对周围建筑物的影响.以合肥地铁一号线芜湖路车站深基坑工程为例,通过对该深基坑西侧某小区相邻住宅楼在开挖全过程的沉降监测及其数据分析,研究深基坑开挖对周围建筑物的影响,将数据及时反馈给施工单位,保证基坑顺利施工,为深基坑设计施工提供参考.     

深基坑降水工程对周边环境的影响及对策

摘要：随着我国城市建设的快速发展，地铁和轨道交通工程日益增多，深基坑开挖成为施工中的必要环节。然后伴随着深基坑开挖的降水工程会对周边环境产生较大影响，成为施工中的一个重要问题。本文结合某地铁深基坑工程实例．针对深基坑施工降水工程如何开展进行分析，并提出了有效的防治措施。     

谈城市高架车站减振

随着我国经济的飞速发展,人民生活水平的提高,城市人口规模历史上首次超过农村.城市化进程的加快,城市规模的不断增加,城市的交通问题日益加剧.因此发展.具有运量大、速度快、安全性能好、准时高效、节能的城市轨道公共交通已是必然.高架线与地铁相比以其经济、设计施工难度小、建设费用低且建设周期短等优点得到广泛的发展和应用.高架车站结构是高架线交通建设中必备的配套结构.论文介绍了高架车站结构的几种基本形式,同时介绍空间框架结构减振措施和方法.     

关于上海市高架道路功能的探讨

通过上海在高架道路规划、设计、建设和运行中的情况分析,充分显示出高架道路在解决城市交通中的重要作用。实践证明,只要扬长避短,在特大城市中,特别是建成区在现阶段建设高架道路是解决城市交通问题的重要和有效的手段。     

高架桥节段梁施工技术

节段梁施工技术在国内正逐步兴起,广州地铁将节段梁施工技术首次大规模应用于城市轨道交通区间高架桥,已经取得了初步阶段性成果.本文以广州市轨道交通四号线高架桥施工为背景,介绍了节段梁的发展情况及施工工艺,并分析了节段梁施工技术的特点.     

对架空连廊抗震设计的探讨

回顾了我国 1 976年唐山地震中若干工业建筑物中直接支承于相连建筑的架空连廊的震害情况 ,并对震害的原因进行了分析。据此提出了架空连廊抗震设计的具体建议 ,如连廊的主体和围护结构都要轻 ,支承结构和支座构件要可靠等 ,可供连廊工程抗震设计时参考。     

Column Web Panel at Elevated Temperature

One of the most recent studied components in the connections of a steel structure exposed to elevated temperature is the column panel loaded in shear. A set of three tests were performed to confirm the analytical prediction model at the Czech Technical University in Prague. The model takes into account the distribution of the internal forces in the shear panel affected by the transfer of the forces by bolt rows in tension. Two panels were tested at ambient temperature and four panels at elevated temperature. The gas temperature in the furnace followed the temperature measured during the seventh Cardington large compartment test in 2003. This contribution is focused on the presentation of the experimental results and an analytical prediction model with a component method.     

高架直升机场及其灯光设计

随着超高层建筑越来越多,高架直升机场地应用也日益增多。为了电气设计人员设计方便,笔者摘录了与高架直升机场地相关的设计规定,并通过案例对相关规定进行解读。文中主要从高架直升机场地施划和场地灯光设置两个方面给予叙述。     

Control of Traffic-Induced Vibrations of Elevated Urban Highways

Abstract: This paper studies the active control of traffic-induced vibrations of elevated highway bridges. In order to suppress the vibration, an active control device (AMD or ATMD) is installed beneath the bridge girder at the center. Three different feedback control algorithms are studied, depending on different levels of vehicle information used in control design, namely, (1) full-state feedback, (2) output feedback, and (3) constant-gain output feedback. The gains of the algorithms 1 and 2 are time-varying, while the gain of algorithm 3 is time-invariant. The numerical examples of bridge-control system responses, subjected to the moving vehicle, are computed. The results demonstrate the effectiveness of the active control in reducing the bridge responses. However, for the control design, the information of passing vehicles is found to be almost unnecessary for inclusion in the feedback, although for the response analysis, it is known that the vehicles form an essential part that should be incorporated in the system dynamic model. It is also found that the control performance of ATMD is higher than that of AMD. Finally, based on the understanding of the control characteristic, a new control concept is proposed. It is shown that the ATMD's performance can be further improved by the proposed control.     

高架公路新型构件-- 沪闵高架公路(二期)预制节段梁生产工艺的研究应用

上海市沪闵高架公路(二期)弧形底钢筋混凝土预应力连续梁采用全断面预制节段梁逐跨拼装施工,国内首次应用,该节段梁的截面宽达25m、高2.1m、弧型底、多箱结构,预制难度罕见。通过比较分析,最后选用“短线法”生产工艺进行预制,并采取多项有效措施,保证了构件的质量。     

无装修高架车站设计关键技术

简述了采用清水混凝土工艺技术的无装修设计在轨道交通高架车站的适用性。针对清水混凝土技术的特点,提出了无装修高架车站的设计关键技术。以上海轨道交通8号线浦江镇站设计为例,介绍了无装修设计关键技术的体现。作为国内轨道交通高架车站首次采用的清水混凝土技术,可供工程设计参考。     

Elevated temperature material properties of stainless steel alloys

Appropriate assessment of the fire resistance of structures depends largely on the ability to accurately predict the material response at elevated temperature. The material characteristics of stainless steel differ from those of carbon steel due to the high alloy content. These differences have been explored in some detail at room temperature, whilst those at elevated temperature have been less closely scrutinised. This paper presents an overview and reappraisal of previous pertinent research, together with an evaluation of existing elevated temperature stainless steel stress-strain test data and previously proposed material models. On the basis of examination of all available test data, much of which have been recently generated, revised strength and stiffness reduction factors at elevated temperatures for a range of grades of stainless steel have been proposed, including four grades not previously covered by existing structural fire design guidance. A total of eight sets of strength reduction factors are currently provided for different grades of stainless steel in EN 1993-1-2 and the Euro Inox/SCI Design Manual for Structural Stainless Steel, compared to a single set for carbon steel. A number of sets of reduction factors is appropriate for stainless steel since the elevated temperature properties can vary markedly between different grades, but this has to be justified with sufficient test data and balanced against ease of design — it has been proposed herein that the eight sets of reduction factors be rationalised on the basis of grouping grades that exhibit similar elevated temperature properties. In addition to more accurate prediction of discrete features of the elevated temperature material stress-strain response of stainless steel (i.e. strength and stiffness reduction factors), a material model for the continuous prediction of the stress-strain response by means of a modified compound Ramberg-Osgood formulation has also been proposed. The proposed model is less complex than the current provisions of EN 1993-1-2, more accurate when compared to test results, and the model parameters have a clear physical significance.