旋挖钻在填海地区厚砂层及厚淤泥层中成孔技术

钻孔灌注桩采用旋挖钻在厚砂层和厚淤泥层中成孔,事故率较高。本文根据深圳机场站旋挖钻成孔施工经验,论述了旋挖钻在填海地区厚砂层和厚淤泥层中成孔施工技术控制措施,为旋挖钻在填海地区厚砂层及厚淤泥层中成孔施工提供技术参考。     

谈深厚砂层中旋挖桩施工技术

分析了厚砂层对旋挖桩施工技术的影响,结合工程实例,对深厚砂层中旋挖桩施工遇到的一系列问题进行了论述,并研究了相应的解决措施,以提高成孔的质量,使孔径、孔深等各项参数指标均可达到设计要求。     

1.7 m结构厚板转换层温度裂缝控制

介绍了结构转换层的模板支撑方案和厚板面保湿方案的选择,阐述了混凝土工程的施工技术措施,经过采用各项技术措施,1.7 m结构厚板转换层没发现裂缝,达到了预期效果.     

Distributed object models for collaboration in the construction industry

Information about products for the construction industry is increasingly often provided to designers in digital ways that enable them to apply the information directly in the design process. Digital product catalogues are provided using various media and formats and several initiatives are taken by the industry and by CAD developers to integrate this kind of information into CAD systems. Generally, current practice is to distribute the information to designers, for example, by using CD-ROMs or a website where the information can be downloaded. In our research, we recognise that distributing information in this manner detaches it from the business processes in the construction supply chain, which is a major disadvantage.The project presented in this paper concerns the implementation in the Dutch construction industry of a methodology for sharing product information through a distributed object model. The methodology, which is called Concept Modelling, forms a generic basis for the support of collaborative design, but is applied in this project to the integration of information from the supply chain in the design process. Through the distributed object model, design information and product information can be integrated while the actual data objects remain at their source. This enables the supply chain to provide information of a high semantic level to designers while keeping the control over the information and maintaining the relationship of the information with their business processes.The advantages of this approach in which information is shared, rather than exchanged, are numerous. Redundancy of information is minimised, consistency is improved, and updated information is available immediately. Moreover, design and construction processes can benefit significantly from the dynamic aspects of accessing information that is tied to business processes in the supply chain. For example, product selection during design can be based on latest information on product details, prices, production methods, and variants of products. This information can be provided to designers automatically and on demand.     

人工干扰下的中继不可信协同传输通信系统物理层安全技术研究

文章针对中继不可信的协同通信系统,采用在信源端发送信号的同时发送人工干扰信号的方式来提高系统的安全性能,使用贪心算法对信源功率进行分配,以求得最大的安全容量,并在此基础上研究了外部窃听节点同时存在的情况。从仿真结果可知该方案在对抗内、外部窃听节点时是安全有效的。     

德士古气化炉的焊接技术

根据德士古气化炉性能要求与结构特点,分别介绍了德士古气化炉的壳体纵缝、环缝和管接头的焊接,以及壳体内壁堆焊。详细阐述了各类焊缝所采用的焊接方法、坡口形式、焊接设备、操作要求,以及所采取的工艺措施,为德士古气化炉的制造提供了重要的技术支持。     

钢混组合梁标准化制造技术

依托国内某高速公路钢混组合梁项目展开研究工作,阐述了由若干标准化单元结构组成的钢混组合梁,采用工厂预制+现场施工的标准化制造技术。通过研究,钢混组合梁标准化制造优势明显,有非常广泛的应用基础。     

某高层住宅钢筋混凝土厚板转换层结构的施工技术

本文结合某高层住宅工程实例,就其中1.8m厚板转换层施工,简要地叙述了钢筋混凝土厚板转换层结构的施工技术。     

北京世纪财富中心工程超大尺寸基础底板混凝土裂缝控制技术

北京世纪财富中心工程超大尺寸基础底板,平面尺寸75m×40m,厚度3m,中心厚度6m,高温季节浇筑。通过技术论证试验和采取一系列裂缝控制措施,不留置后浇带、施工缝,不设置膨胀加强带,不掺加任何特殊防水材料,12000m3混凝土一次性整体连续浇筑成功。     

Modern technology and equipment for manufacturing and sinking tubular drains

This article considers new designs of vertical drains recommended for compaction of soft, water-saturated soils. The advantages and fields of application of tubular drains are pointed out. Technical characteristics of the equipment for manufacturing and sinking them are given.Scientific Research Institute of Foundations and Underground Structures. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 5, pp. 14–15, September–October, 1993.     

回转窑生产人造轻骨料的烧成技术

本文以人造轻骨料膨胀机理和生产实践为基础，分析人造轻骨料的形成过程，从燃料、燃烧设备的准备和温度、压力、气氛、窑转速等工艺、热工因素的调节，阐述回转窑生产人造轻骨料的烧成技术。     

A physical design grammar: A production system for layered manufacturing machines

This paper addresses the need to generate functionally large geometries/objects for layered manufacturing machines. Novelty is found in the translation from an initial shape in CAD to subdivision as interlocking objects that are further subdivided into slicing layers using traditional layered manufacturing software. Translation from an initial shape to individual component geometry is guided by shape rules as a set grammar that generate a 2D drawing of interlocking shapes. Mechanical rules further shape the 3D geometry of each object, resulting in a virtual model that complies with measures of structural stability, assembly, and machine manufacturing. Three models are constructed to illustrate the translation process from the virtual shape to a manufactured artifact.     

深厚覆盖层防渗墙成槽稳定性的三维数值分析

为分析深厚覆盖层地区在泥浆护壁条件下的防渗墙成槽稳定性,从槽壁失稳机理上分析泥浆的护壁作用;并结合西藏某直孔电站实际工程,采用有限差分法,分析防渗墙成槽开挖过程中的槽壁应力和变形变化特性。结合泥浆护壁条件下的槽壁应力及变形变化规律,提出提高防渗墙造孔期间槽壁稳定性的有效措施。     

Combined prediction model for mining subsidence in coal mining areas covered with thick alluvial soil layer

The entire overburden stratum above a coal mining area is considered to be composed of an alluvial soil layer and a bedrock layer. In underground mining, alluvial soil has a major effect on ground subsidence. This effect is especially significant and not negligible when the alluvial soil accounts for a large proportion in the entire overlying stratum of coal mining areas covered with thick alluvial soil (CMATASs). In this study, the applicability of the most popular probability integral method (PIM) used for CMATASs was analyzed, and it was found that the PIM is not suitable for ground subsidence prediction in CMATASs for two main reasons: (1) the subsidence basin range predicted by the PIM was smaller than the measured range; thus, the predicted basin converged more rapidly than the measured basin at the edges. (2) Poor fitting results were obtained at the subsidence basin edge. The mechanism of mining subsidence in CMATASs and the reasons why the PIM is not suitable for CMATASs were investigated in terms of the internal deformation and crack (void) distribution within the rock mass induced by underground coal mining. The results indicate that the alluvial soil is compacted and then subsides under vertical compression deformation, which increases ground subsidence. The bedrock is subjected to the weight/load of the thick alluvial soil layer. Because of the vertical compression deformation inside the rock, its internal voids (spaces) are compacted; thus, the replaced voids (spaces) are transferred to the ground surface, resulting in an increase in ground subsidence. However, the effect of the alluvial soil on ground subsidence cannot be detected by the PIM; moreover, the PIM is unable to represent the mechanism of the mining subsidence in CMATASs. Thus, the PIM cannot be used for predicting subsidence in CMATASs. To precisely calculate subsidence in CMATASs, we propose a combined prediction model (CPM) for mining subsidence in CMATASs based on soil mechanics and stochastic medium theory. The new CPM was applied to the mining process in the Huainan Coal Mining Area. The calculation results show that subsidence predicted by the CPM better fits the measured subsidence values, with a relative error of 4.9%, and that the fitting accuracy is improved by 18% compared to the relative error of the PIM (6.0%). Thus, the proposed CPM is more suitable for predicting ground subsidence caused by underground coal mining in CMATASs, and can be used to provide more accurate predictions for ground subsidence in similar coal mining areas.     

Augmented process model for e-tendering: Towards integrating object models with document management systems

The management of the construction industry is exponentially increasing in complexity since it has to deal with highly fragmented, complex and unique combinations of business relations, communications and processes. Each phase in the construction cycle requires effective communication/sharing of information/knowledge as well as coordination among project participants and stakeholders, thus leading to timing and technical content transfer enhancements and/or problems as well as related efficiency and/or profitability loss. Recent advances in the Information and Communication Technology (ICT) are considered essential and promising in improving sharing/exchange of project information as well as communication among construction industry stakeholders whilst reducing associated costs and time.One facet of such advances in ICT is evident from the proactive indulgement of the construction supply chain in collaborative extranets. Extranets are able to capture the supply chain communication practices and provide a controlled communication hub as well as document management databases with all ICT enhanced features. In parallel, the construction industry has recognized the importance of sharing and exchanging project information across the supply chain through project integrated databases. However, such advancements in the ICT utilisation in construction industry were unable to develop a system that exchanges/shares project information, at the element level, over a well defined matrix of communication that can also integrate into the business processes of the members of supply chain.The objective of this study is to highlight the needs to bridge this gap through the development of an augmented process model which will enable integrated databases to support collaborative extranets at the Tender stage. This paper will discuss the features, limitation and nature of the process and information models which can be integrated into the core business processes of the construction supply chain members. This is basically achieved by investigating the communication processes and information exchanged across the supply chain during the construction tendering phase.     

路面多孔水泥混凝土制备技术研究综述

介绍多孔混凝土原材料选择、工作性试验与评价方法及室内成型工艺等方面研究现状.针对路面多孔混凝土存在的问题,提出多孔混凝土制备技术的实质即成功控制多孔混凝土在不同阶段的目标孔隙率和理想孔隙状态,并就最佳目标孔隙率、骨架-孔隙结构的增强和改性、路面构造参数优化及基于目标孔隙率的配合比设计方法等关键问题,综述自身研究成果,具有较大的参考价值.     

Digital and physical models for the validation of sustainable design strategies

Contemporary architecture is generally characterised by shapes whose complexity, according to a multidisciplinary design approach, is related to the fulfilment of several requirements, such as structural and thermal efficiencies, exploitation of renewable energy sources, and reduction of construction and maintenance costs.In this framework, the paper introduces and discusses the use of physical and numerical models for the validation of a sustainable tower design; the modelling of the building was developed at different levels, making use of computer numerical control (CNC) techniques. Rapid prototyping (RP) was used in the early design stages for the verification of the architectural concept, while more detailed experimental tests were carried out in a wind tunnel facility, with a rigid model. The case study had as its goal the integration of two conflicting needs: a clever exploitation of wind energy and the limitation of wind speeds in the living spaces of the tower. This process of graphical modelling, physical modelling, and experimental performance testing allowed researchers to overcome the limitations of the currently available analytical models, showing new fields of application of rapid prototyping and how technical drawing can help sustainable design.     

重庆东水门长江大桥中纵梁制造关键技术

简述了重庆东水门长江大桥中纵梁的结构构造,从焊接变形控制、钻孔精度控制、钢锚箱组装精度控制等方面,分析了中纵梁制造的重难点,并阐述了主要零部件制作与组装的工艺流程,保证了中纵梁制造技术的科学性。     

深基坑软土地层真空降水施工技术

以某地铁站深基坑软土地层真空降水施工为例,探讨了基坑降水方式的选择及设计方法,归纳了真空降水的施工方法及管理措施,实践证明采用该法达到了基坑降水及排水固结的目的,从而取得了良好的经济效益。     

塑胶地面基层水泥自流平施工技术

本文以某排练及艺术展厅的地面施工为实例,详细介绍塑胶地面基层水泥自流平精找平的施工技术。