荒沟抽水蓄能电站地下系统工程施工支洞布置

荒沟抽水蓄能电站地下系统工程埋藏深、开挖量大,施工通道的布置直接影响各洞室的施工条件和工程工期,该工程经过反复研究比较后,在充分利用永久洞室基础上,另外布置了7条施工支洞,提高了施工效率。

综合交通枢纽智能化系统刍论

交通运输是一个复杂的大系统 ,应该运用交通运输系统工程的理论方法研究与发展我国交通运输系统 ,我国政府提出以发展综合交通体系为目标进行我国交通运输的综合发展 ,但长期以来由于管理体制以及其他原因致使我国综合交通运输系统没有能达到综合协调全面发展的目标 .作者长期从事交通运输系统工程的研究 ,特别是最近几年从事智能交通运输系统工程的研究 ,参加了由国家科技部下达的上海综合交通枢纽规划协调与智能化发展的研究 ,提出了通过交通运输智能化工程的研究和开发推动综合运输体系的形成与发展的基本观点 .并分析了综合交通枢纽的功能、结构及内部的组织与生产 ,并在此基础上提出了建立综合交通信息工程 ,在各种运输方式信息化的基础上进行联网 。

Developing a risk assessment system for gas tunnel disasters in China

Gas disasters always restrict the tunnel constructions in mountain area, which becomes a major geological barrier against the development of underground engineering. China is rich in coal resources and has a large amount of gas with a wide range of distribution. However, China experienced not only adverse effects on coal mining but also gas disasters in underground engineering construction, such as tunnels and chambers. With the increased number of tunnels passing through coal-bearing strata, the incidence of gas accidents is also rising. Therefore, the significance of preventing and mitigating gas disasters should be emphasized, and an effective risk assessment method for gas disasters should be established. On the basis of research on over 100 gas tunnels in China, a relatively ideal gas disaster risk assessment method and system for tunnels are established through the following measures. Firstly, geo-environmental conditions and gas situations were analyzed during construction. Secondly, qualitative analysis was combined with quantitative analysis. Finally, the influencing factors of gas disasters, including geological conditions, gas,and human factors, were investigated. The gas tunnel risk assessment system includes three levels:(1) the grading assessment of a gas tunnel during the planning stage,(2) the risk assessment of gas tunnel construction during the design and construction stages,(3) the gas tunnel outburst risk assessment during the coal uncovering stage. This system was applied to the dynamic assessment of gas disaster during the construction of the Zipingpu tunnel of Dujiangyan–Wenchuan Highway(in Sichuan, Southwest China). The assessment results were consistent with the actual excavation, which verified the rationality and feasibility of the system. The developed system was believed to be back-up and applied for risk assessment of gas disaster in the underground engineering construction.

Application of Norms Models with Vectoral System in Construction Projects

Normization, i.e., the system of norms is a structure that defines the group of elements containing the norm values for the requirements of a certain resource. Resources comprise of materials, machines and labor. All the requirements of the measure units of the resources are given statically and with the discrete data. Thus, every slight change in the expense list item reference causes a change in norm and our norm is not flexible and features a discrepancy with the real life situations. In order to achieve a higher level of preciseness and to speed up the technological processes of planning and norming the engines of a company that lead to the regulation of the system, the discrete elements of the working （time-related） norms should be replaced by the dynamic ones. This is made possible through setting up norms models that in turn can be presented by formulae in the vectoral system. The use and implementation of the new technologies in terms of production, computer science and cybernetics provides for upgrading the norm requirements. New working tasks in turn require a new norm standardization, which can be applied to the hydrodemolition of concrete constructions by means of water robots that use high pressure water jets.

New Approach to the Delivery of Construction in Botswana

The construction industry in Botswana has been identified as an industry with many problems. Currently the Botswana government uses the design-bid-build process, using prequalification and awards to the lowest bidder for construction services. The government can also use the design-build delivery system. The current delivery system uses an engineering group that delivers designs and construction, uses a procurement group to award the contract and contract modifications. However, the analysis for all actions is done by the engineering group. The model is very similar to the Corps of Engineers traditional processes in the United States. Construction performance （on time and no contract deviations） has not been good. The authors propose that the delivery system and the paradigm of direction, control and decision making by the engineering group causes risk to the project and results in poor contractor performance. The authors suggest making modifications in the process and to use the design-build process. The authors also propose to change the paradigm using best value PIPS/IMT concepts.

Discussion Based on Formwork Construction of Box Girder Formwork Design Scheme

Formwork construction has been the important and difficult of the construction process, so the design plan is very important. This paper relies on the Shun Ping Yu subordinate Fertgbo bridge rebuilding project, detailing the cast-in-place box beam formwork support system safety special construction plan, focuses on box girder formwork design scheme of foundation design, box girder bracket design and box girder formwork design, to provide a reasonable reference for similar projects.

Bridge Falsework in Staged Construction of a Prestressed Concrete Beam Bridge

The formwork and falsework in the construction of twin ribbed slab decks on a multi-span ecological bridge for a dual carriageway are presented. The bridge is situated in a valley plain which is crossed by small rivers and was designed principally with the environment in mind. The bridge length is over 356 m, and the width of the decks is 11.5 m. For the bridge works, a simple conventional falsework system was chosen with steel frames for the supports and steel rolled beams for the decks. The formwork was constructed in solid timber and plywood as multiple-use panels. The falsework was designed in order to build the two 10-span bridge decks in stages. The decks are continuous cast-in-situ prestressed concrete twin rib with spans of 30 m, 34 m and 45 m. An individual falsework system was designed, which was easy to move transversally following completion of each stage for one deck. After finishing each stage, for the second deck, the falsework was dismantled and used again in the next construction fronts. An individual arrangement for the falsework along with timber pilings was used to cross the biggest river. The formwork timber panels were used several times in the multistage bridge construction. The adopted falsework system is very simple, but it allowed the speedy construction of the two decks where there were severe time constraints.