Next Generation CANDU: Conceptual Design for a Short Construction Schedule

2002 ◽  
Author(s):  
Jerry M. Hopwood ◽  
Ian J. W. Love ◽  
Medhat Elgohary ◽  
Neville Fairclough
Keyword(s):  
Conceptual Design ◽  
Critical Path ◽  
Construction Method ◽  
Phase Iii ◽  
Next Generation ◽  
Project Schedule ◽  
Construction Methods ◽  
New Construction ◽  
Construction Strategy ◽  
Construction Schedule

Atomic Energy of Canada Ltd. (AECL) has very successful experience in implementing new construction methods at the Qinshan (Phase III) twin unit CANDU 6 plant in China. This paper examines the construction method that must be implemented during the conceptual design phase of a project if short construction schedules are to be met. A project schedule of 48 months has been developed for the nth unit of NG (Next Generation) CANDU with a 42 month construction period from 1st Concrete to In-Service. An overall construction strategy has been developed involving paralleling project activities that are normally conducted in series. Many parts of the plant will be fabricated as modules and be installed using heavy lift cranes. The Reactor Building (RB), being on the critical path, has been the focus of considerable assessment, looking at alternative ways of applying the construction strategy to this building. A construction method has been chosen which will result in excess of 80% of internal work being completed as modules or as very streamlined traditional construction. This method is being further evaluated as the detailed layout proceeds. Other areas of the plant have been integrated into the schedule and new construction methods are being applied to these so that further modularization and even greater paralleling of activities will be achieved. It is concluded that the optimized construction method is a requirement, which must be implemented through all phases of design to make a 42 month construction schedule a reality. If the construction methods are appropriately chosen, the schedule reductions achieved will make nuclear more competitive.

scholarly journals SCHEDULING WORK UNDER INTEGRATED URBAN DEVELOPMENT USING THE METHOD OF UNCERTAIN RESOURCE COEFFICIENTS

2021 ◽  
Vol 6 (4) ◽  
pp. 34-41
Author(s):  
Sergey Bolotin ◽  
◽  
Haitham Bohan ◽  
Aldyn-kys Dadar ◽  
Khenzig Biche-ool ◽  
...  
Keyword(s):  
Project Management ◽  
Critical Path ◽  
Equation System ◽  
Adaptation Mechanism ◽  
Integrated Development ◽  
Construction Methods ◽  
Visual Basic For Applications ◽  
Linear Equation System ◽  
Integration Mechanism ◽  
Construction Schedule

Introduction: Planning integrated development of a residential area involves determining the composition of the objects to be built and creating an appropriate integration mechanism, backed up by a generalized work schedule. The existing methods of forming integrated work schedules do not use a systemic approach, based on a universal mathematical model, to describe the organizational and technological aspects of construction. Methods: The present study uses the method of uncertain resource coefficients to demonstrate a mechanism for systemically describing organizational and technological construction processes. We present a way of adapting this method to forming a generalized construction schedule during integrated development. The proposed adaptation mechanism is based on managing schedule calculations by rationally influencing the elements of the linear equation system that describes the organizational and technological processes. Results and Discussion: The solutions presented in the paper are fully consistent with the calculations obtained by different flow methods of organizing construction, as well as with the critical path method used in project management programs. The method described in the paper has been implemented in well-known project management software, Microsoft Project, as a macro program in the Visual Basic for Applications programming language, making it possible to form, calculate, and optimize a schedule for integrated territory development using the unified software toolkit.

Advanced Construction Methods for New Nuclear Power Plants

2010 ◽  
Author(s):  
Dae-Yul Jung ◽  
Yoon-Kee Kang ◽  
Chang-Hyung You
Keyword(s):  
Construction Projects ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Critical Path ◽  
Development Program ◽  
3D Cad ◽  
Cad System ◽  
Construction Methods ◽  
Construction Schedule

This paper covers advanced construction technologies that are generally used for nuclear power plants and presents advanced construction methods that can contribute to an efficient and short construction schedule. The construction schedule is driven by the activities of the critical path. The advanced construction methods consist of Modularization, Improvement of Mechanical Rebar splices, Application of 3D-CAD system for information and control, and the installation of RVI and RCL at the same time. Some methods have been applied in actual Nuclear power projects and others have been developing under the research and development program. It incorporates the experiences and insights from recent nuclear construction projects all over the world.

scholarly journals Comparison of the New Type Modular Panel for Green Roofs and Classical Construction of Green Roofs by Stormwater Management

2021 ◽  
Vol 1203 (2) ◽  
pp. 022118
Author(s):  
Martin Hejl ◽  
M. Mohapl ◽  
Lukas Bříza
Keyword(s):  
Stormwater Management ◽  
Laboratory Tests ◽  
Green Roofs ◽  
Construction Method ◽  
Measured Data ◽  
Urban Stormwater ◽  
Construction Methods ◽  
New Construction ◽  
New Type ◽  
Classical Construction

Abstract Proper stormwater management is one of the main problems cities today face. In order to understand how to properly manage urban stormwater it is first necessary to construct roofs with new construction methods. The first step for controlling urban stormwater is the construction of green roofs. We already know that the construction of green roofs improves water management in cities. But can we make it better? What will happen if we use the same layers for the green roofs but with a different construction method? This article wants to answer these questions. In this article the two green roofs, differing in the construction method, are compared and contrasted in terms of stormwater management. One of the green roofs was built traditionally, while the other has been built using a new type of modular panel. The article then compares their results during laboratory tests. In the conclusion you can read about measured data from tests and possible solutions and development of solutions to improve green roofs in the future.

Numerical Analysis of Metro Station Construction by Large-Diameter Shield and Pile-Beam-Arch Method

2011 ◽  
Vol 368-373 ◽  
pp. 2711-2715 ◽  
Author(s):  
De Yun Ding ◽  
Xiu Ren Yang ◽  
Wei Dong Lu ◽  
Wei Ning Liu ◽  
Mei Yan ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Large Diameter ◽  
Element Model ◽  
Construction Method ◽  
Shield Tunnel ◽  
Outer Diameter ◽  
Shield Tunneling ◽  
Metro Station ◽  
Dimensional Finite Element ◽  
New Construction

In more and more complicated urban building environment, a new construction method that metro engineering is constructed by large-diameter shield and shallow mining method can be regarded as a great attempt in China. By taking the Gaojiayuan station of Beijing metro line 14 as an engineering background, the main construction steps for the platform of the metro station built by a large-size shield with an outer diameter of 10 m and the Pile-Beam-Arch (PBA) method are introduced. Based on the soil-structure interaction theory, a two-dimensional finite element model is used to simulate the shield tunneling and the platform construction by the PBA method to enlarge the shield tunnel. The ground deformation and structural stress of the platform are predicted. The numerical results can be regarded as a valuable reference for the application of the new construction method in Beijing metro line 14.

scholarly journals Tailings facility disclosures reveal stability risks

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel M. Franks ◽  
Martin Stringer ◽  
Luis A. Torres-Cruz ◽  
Elaine Baker ◽  
Rick Valenta ◽  
...  
Keyword(s):  
Information Disclosure ◽  
Significant Risk ◽  
Construction Method ◽  
Facility Management ◽  
Alternative Technologies ◽  
Construction Methods ◽  
Comprehensive Survey ◽  
Engineering Standards ◽  
The Right ◽  
Stability Issues

AbstractTailings facility failures represent a significant risk to the environment and communities globally, but until now little data was available on the global distribution of risks and characteristics of facilities to ensure proper governance. We conducted a survey and compiled a database with information on tailings facilities disclosed by extractive companies at the request of institutional investors. Despite limitations in the data, this information disclosure request represents the most comprehensive survey of tailings facilities ever undertaken. The compiled dataset includes 1743 tailings facilities and provides insights into a range of topics including construction method, stability, consequence of failure, stored volume, and the rate of uptake of alternative technologies to dewater tailings and reduce geotechnical risk. Our analysis reveals that 10 per cent of tailings facilities reported notable stability concerns or failure to be confirmed or certified as stable at some point in their history, with distinct trends according to construction method, governance, age, height, volume and seismic hazard. Controversy has surrounded the safety of tailings facilities, most notably upstream facilities, for many years but in the absence of definitive empirical data differentiating the risks of different facility types, upstream facilities have continued to be used widely by the industry and a consensus has emerged that upstream facilities can theoretically be built safely under the right circumstances. Our findings reveal that in practice active upstream facilities report a higher incidence of stability issues (18.3%) than other facility types, and that this elevated risk persists even when these facilities are built in high governance settings. In-pit/natural landform and dry-stack facilities report lower incidence of stability issues, though the rate of stability issues is significant by engineering standards (> 2 per cent) across all construction methods, highlighting the universal importance of careful facility management and governance. The insights reported here can assist the global governance of tailings facility stability risks.

Ensemble Construction and Verification of the Probabilistic ENSO Prediction in the LDEO5 Model

2010 ◽  
Vol 23 (20) ◽  
pp. 5476-5497 ◽  
Author(s):  
Yanjie Cheng ◽  
Youmin Tang ◽  
Peter Jackson ◽  
Dake Chen ◽  
Ziwang Deng
Keyword(s):  
High Frequency ◽  
Singular Vector ◽  
Southern Oscillation ◽  
Initial Perturbation ◽  
Probabilistic Prediction ◽  
Construction Methods ◽  
Sea Surface Temperature Anomaly ◽  
Probabilistic Forecasts ◽  
Construction Strategy ◽  
Construction Strategies

Abstract El Niño–Southern Oscillation (ENSO) retrospective ensemble-based probabilistic predictions were performed for the period of 1856–2003 using the Lamont-Doherty Earth Observatory, version 5 (LDEO5), model. To obtain more reliable and skillful ENSO probabilistic predictions, first, four ensemble construction strategies were investigated: (i) the optimal initial perturbation with singular vector of sea surface temperature anomaly (SSTA), (ii) the realistic high-frequency anomalous winds, (iii) the stochastic optimal pattern of anomalous winds, and (iv) a combination of the first and the third strategy. Second, verifications were conducted to examine the reliability and resolution of the probabilistic forecasts provided by the four methods. Results suggest that reliability of ENSO probabilistic forecast is more sensitive to the choice of ensemble construction strategy than the resolution, and a reliable and skillful ENSO probabilistic prediction system may not necessarily have the best deterministic prediction skills. Among these ensemble construction methods, the fourth strategy produces the most reliable and skillful ENSO probabilistic prediction, benefiting from the joint contributions of the stochastic optimal winds and the singular vector of SSTA. In particular, the stochastic optimal winds play an important role in improving the ENSO probabilistic predictability for the LDEO5 model.

Bridge bearing solutions that facilitate quick and efficient bearing installation and bridge construction

2019 ◽  
Author(s):  
Simon Hoffmann ◽  
Amit Kutumbale ◽  
Danilo Della Ca'
Keyword(s):  
Load Distribution ◽  
Construction Method ◽  
Construction Process ◽  
Vital Function ◽  
Bridge Construction ◽  
Construction Methods ◽  
Efficient Construction ◽  
Critical Components ◽  
Bridge Bearing ◽  
Segmental Bridge

<p>A bridge’s bearings, arguably its most critical components, perform a vital function throughout the bridge’s service life, but the bearings used can also have a significant impact on the bridge construction process. Suitably designed adjustable bearings are an integral part of the incremental launch method of bridge construction, for instance, which can be a very efficient construction method. Adjustable bearings may also support other bridge construction methods, such as segmental bridge construction, where fixities/freedoms that applied during the construction phase require to be changed before the bridge enters service. Lifting bearings, the height of which can be increased, may enable a lack of precision in the structure to be tolerated, and measuring bearings may enable load distribution during bridge construction to be verified, where this is required by the construction method. Design features of otherwise standard bearings that support quick and high-quality installation can also contribute towards the efficiency of the overall bridge construction process, as can the use of bearing designs which minimize bearing size. Bearing solutions and features that facilitate bearing installation and bridge construction in ways such as these are described.</p>

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