超大面积深基坑逆作法施工技术的探讨

针对上海铁路枢纽南站北广场基坑工程,在采用主体结构与支护结构相结合的逆作法施工过程中,对超大面积深基坑采取了一柱一桩垂直度控制、降微承压水、大开口、盆式和分块平衡对称抽条开挖以及节点处理等措施,解决了超大面积深基坑逆作法施工的一些关键施工技术.     

超大面积深基坑工程半逆作法施工实践

采用地下连续墙同时兼作地下室外墙的"两墙合一"围护结构形式进行全逆作法施工,在已建工程项目中比较多见,而上海外高桥森兰商都二期超大面积深基坑工程,因地制宜,采用了非"两墙合一"的排桩围护体系半逆作法施工。实践证明,超大面积深基坑工程采用半逆作法施工,既能降低基坑围护费用、减小基坑变形,又能保护周围环境,具有良好的社会效益和经济效益。     

深基坑工程逆作法施工

随着深基坑支护技术的发展,逆作法施工已得到广泛应用,它解决了施工场地小,邻近建筑物因开挖基坑而出现地基变形等问题,是基坑支护效果较好的一种。     

深基坑逆作法中的梁柱节点关键施工技术

采用逆作法施工对多层地下结构工程具有良好的社会效益和经济效益,只是施工工艺较为复杂。以上海国际金融中心项目为背景,针对深基坑逆作法中的梁柱节点施工技术进行了研究优化,不仅有效地解决了工程施工关键难点,而且也进一步保证了结构施工质量。     

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。     

超大面积深基坑工程非两墙合一的半逆作法设计

大多数逆作法基坑是采用地下连续墙作围护结构,同时也作为地下室结构外墙的所谓“两墙合一”的围护结构形式。以由由大酒店二期工程超大面积深基坑工程为例,采用非“两墙合一”的排桩围护基坑工程半逆作法施工,介绍了设计要点厦几个关键节点。实践证明,超大面积深基坑工程半逆作法方案,取得了明显的经济和社会效益。     

超大基坑逆作法施工监测分析

以天津某交通枢纽工程为例,通过基坑开挖过程中水平支撑结构板内力、围护结构及墙后土体水平位移实测资料分析,得出了逆作法异于顺作法的变化规律,由分析结果可知逆作法位移小的特点,为类似工程提供参考。     

逆作法深基坑在软弱地层中的应用

文章从深基坑施工的顺作法和逆作法比较入手,结合某项目工程实例,对软弱地层中逆作法深基坑的施工工艺和重点难点进行阐述,并提出安全、质量保证的措施。最后指出逆作法在类似地质状况下的不足,为同类工程设计、施工提供借鉴。     

高层建筑深基坑逆作法施工的控制

针对高层建筑深基坑工程逆作法施工的特殊要求,论述了在软土地基条件下对运作法施工中关键技术的控制和关键线路过程的控制方法。     

工业和生活废弃物的利用与混凝土的使用安全

随着天然砂石自然资源的日渐枯竭,工业废弃物、建筑垃圾和污泥等加工后作为人造粗、细集料用于混凝土,掺入水泥中作混合材,以及作为混凝土的掺合料和矿物外加剂,促进了资源再生利用和节能减排工作.加强废弃物的成分研究,规定其有害物质限量,防止利用不当,造成对环境的二次污染,影响混凝土的耐久性与使用寿命,应是当前研究的重点.     

Using hot-mixed concrete

As a development of steam curing, some precasting methods now inject steam into the mixers, obviating the need for expensive moulds and reducing curing time. Some of the pitfalls have been examined at Chalmers University, Gothenburg, through a research grant from the Swedish Council for Building Research, and are reported in its Research Summary S46: 1976.     

Using polymer concretes

The advantages and disadvantages of using resin concretes and polymer modified concrete are described by members of the research staff of Taylor Woodrow Construction Ltd, the UK construction company.

Detailed data is given based on several years' experience, and the authors suggest that applications have so far been limited not only by the high cost of the new materials but by the lack of relevant information about them.     

原有地基利用

地基土经长期压实作用,其状态和水文地质条件、土体结构,都发生了质的变化．依据这一原理,汇集有关资料、结合工程实例,具体阐述了原有地基在荷载长期作用下,地基承载能力的计算方法．对改造项目,利用此法可避免繁杂的基础加固工作,节约投资,缩短工期,提高综合效益     

Using a thermal manikin

There are reputed to be only ten examples of the thermal manikin (a computerized doll) in the world at present. Here, the author discusses their potential in microclimate research, and describes experiments with a thermal manikin at the Hungarian Institute for Building Science (ETI) to identify the quality of indoor comfort conditions. One study revealed that the correct heating system would yield better results than extra thermal insulation.     

Using a thermal manikin

There are reputed to be only ten examples of the thermal manikin (a computerized doll) in the world at present. Here, the author discusses their potential in microclimate research, and describes experiments with a thermal manikin at the Hungarian Institute for Building Science (ETI) to identify the quality of indoor comfort conditions. One study revealed that the correct heating system would yield better results than extra thermal insulation.     

Flood Routing Using Spreadsheet

Abstract: Flood routing is one of the very important basic topics that is dealt with in the first course in hydrology. To illustrate the solution of the Muskingum method requires the computation of K and X, Which are usually obtained using the graphical approach. Similarly, reservoir routing requires a storage function, and a semigraphical approach is adopted. The hydraulic method of routing of flood requirs a knowledge of the soulution of nonlinear hyperbolic partial differential equations. In this paper, spreadsheet of LOTS 1–2-3 has been used to demonstrate its potential as a pedagogical tool for solving flood routing problems for both the hydrological and hydraulic approaches.     

变频器的使用

<正>随着变频技术的提高,交流电动机的应用越来越广泛。在砖瓦生产中,利用变频技术提高生产机械的控制精度、生产效率和产品质量的设备越来越多,变频技术的应用不仅有利于实现生产过程的自动化,而且具有显著的节能效果。     

Tide Prediction Using Neural Networks

Prediction of tides at a subordinate station located in the interior of an estuary or a bay is normally done by applying an empirical correction factor to observations at some standard or reference station. This paper presents an objective way to do so with the help of the neural network technique. In complex field conditions this approach may look more attractive to apply. Prediction of high water and low water levels as well as that of continuous tidal curves is made at three different locations. The networks involved are trained using alternative training algorithms. Testing of the networks indicated satisfactory reproduction of actual observations. This was further confirmed by a high value of the accompanying correlation coefficient. Such a correlation was better than the one obtained through use of the statistical linear regression model. The training algorithm of cascade correlation involved the lowest training time and hence is found to be more suitable for adaptive training purpose.     

Hydrological Information Transfer Using HOMS

The Hydrological Operational Multipurpose Subprogramme (HOMS) scheme of the World Meteorological Organization (WMO) consists of an international network for the transfer of packages of proven hydrological know-how, with particular emphasis on helping developing countries. More than one hundred HOMS centres worldwide produce and supply information components and handle requests for components for use in their own countries. Details are presented of the organization and operation of HOMS, together with example case studies to illustrate its successful use.