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Robustness analysis of underground powerhouse construction simulation based on Markov Chain Monte Carlo method

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Science China(Technological Sciences) 2016年第2期59卷 252-264页

作者： ZHONG DengHua BI Lei YU Jia ZHAO MengQi State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin University

Scheduling is a major concern in construction planning and management, and current construction simulation research typically targets the shortest total duration. However, uncertainties are inevitable in actual construction, which may lead to discrepancies between the actual and planned schedules and increase the risk of total duration delay. Therefore, developing a robust construction scheduling technique is of vital importance for mitigating disturbance and improving completion probability. In the present study, the authors propose a robustness analysis method that involves underground powerhouse construction simulation based on the Markov Chain Monte Carlo(MCMC) method. Specifically, the MCMC method samples construction disturbances by considering the interrelationship between the states of parameters through a Markov state transition probability matrix, which is more robust and efficient than traditional sampling methods such as the Monte Carlo(MC) method. Additionally, a hierarchical simulation model coupling critical path method(CPM) and a cycle operation network(CYCLONE) is built, using which construction duration and robustness criteria can be calculated. Furthermore, a detailed measurement method is presented to quantize the robustness of underground powerhouse construction, and the setting model of the time buffer is proposed based on the MCMC method. The application of this methodology not only considers duration but also robustness, providing scientific guidance for engineering decision making. We analyzed a case study project to demonstrate the effectiveness and superiority of the proposed methodology.

关键词： underground powerhouse construction schedule simulation model MCMC method robustness

Integration of Radio-Frequency Identification and 4D CAD in construction Management

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Tsinghua Science and Technology 2008年第S1期13卷 151-157页

作者：胡文发 Department of construction Management and Real Estate Tongji University

In order to increase the productivity of construction industry, emerging technologies have been constantly introduced and applied in this traditional industry by pilot researchers. This paper provides an integrated model of radio-frequency identification (RFID) and four-dimensional Computer-Aided Design (4D CAD) in construction management. RFID involves the use of tags that collect data and transmit data. RFID can collect data by radio waves instead of light waves. RFID technology is surpassing barcode technology where light waves are easily blocked and barcode labels are easy to fall off or become unreadable due to dust, dirt, or other contaminants. 4D CAD which involves 3D construction models and construction schedules presents visualized construction process. Integration of RFID and 4D CAD in this paper built a dynamic construction management and control system which would reduce the time of capturing data on site and control quality of construction materials efficiently. Pilot test result shows that a construction manager can easily understand how and what a complicated construction project will be accomplished. Although further analysis is necessary, RFID and 4D CAD show promises of being a beneficial technology in construction management.

关键词： radio frequency identification (RFID) four-dimensional computer-aided design (4D CAD) construction management construction visualization construction schedule

Comparative analysis of cast-in-place post-tensioned and steel-concrete composite bridge bent caps

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Journal of Modern Transportation 2017年第3期25卷 194-204页

作者： Nur Yazdani Francisco D.B.Ruiz Department of Civil Engineering University of Texas at Arlington Structural Engineer Ferrovial-Agroman

The complexity of the IH-635 Managed Lanes Project, located in Dallas County, Texas, posed several technical and constructive challenges, leading to the adoption of solutions different from the traditional. Two alternative solutions for the pier cap on one of the bridge crossings over IH-35E in the IH-635 project were analyzed in this case study, a cast-in-place post-tensioned concrete cap and an innovative prefabricated steel-concrete com- posite cap. The approach was to use an estimation of direct costs for material and labor and consideration of con- struction time schedules. A supplementary numerical modeling confirmed that both alternatives behave elasti- cally under imposed loads. The direct cost of material and labor for the two alternatives were close. However, the composite alternative required 13 days less construction time, resulting in substantial cost savings from traffic closing in the very busy traffic corridor. Traffic closing costs were substantially higher than the direct costs, especially for the post-tensioned cap. The quantification of the benefits allows more confidence in the utilization of the composites caps, leading to faster completion of bridge projects and substantial economic savings.

关键词： Bridge pier cap Bridge bent - Post-tensionedstructure Steel-concrete cap Cost estimation construction schedule Traffic closing cost