Comparison of the planned and actual course of construction of reinforced concrete monolithic structures

During construction, there is often a change in contractual terms, either in advance of construction or delayed construction. This phenomenon is due to many influencing factors such as delayed subcontracting, climatic conditions, the surrounding construction site, the quality of project documentation, the solvency of the investor, the expertise of the general contractor, etc. The aim of the paper is to assess the planned and actual construction of reinforced concrete monolithic structural elements using tower cranes. The subject of the paper is to state the expected method of implementation in time and how the construction proceeded. Milestones for accelerating and slowing down construction, analyzing their causes and proposing future measures will be presented. Data are obtained by measuring real buildings.

The Effect of Fairness Concern on Carbon Emission Reduction and Revenue Distribution in Construction Supply Chain: Power Structure Perspective

This paper invested a two-echelon construction supply chain that consists of a general contractor and a subcontractor. This paper constructs the centralized model and the decentralized models, respectively, and studies the emission reduction and revenue distribution strategies of construction supply chain considering fairness concern and cap-and-trade. Numerical analysis is carried out to analyze the influence of cap-and-trade and fairness concern on the optimal decision and the maximum profit of construction supply chain. This paper shows that, under cap-and-trade policy, the centralized model has the best emission reduction effect and the highest supply chain profit without fairness concern, while the general contractor’s Stackelberg model has the best emission reduction effect and the highest supply chain profit with fairness concern. In the two scenarios, the Vertical Nash model is the most unfavorable to emission reduction, and it will also seriously damage the interests of enterprises. In practice, supply chain should choose the general contractor’s Stackelberg model and avoid the Vertical Nash model. Because fairness concern of the subcontractor will damage the supply chain profits and emission reduction performance, the general contractor shall try to select the subcontractor with lower fairness concern to avoid the loss of profit. Besides, enterprises should actively take measures to reduce fairness concern, such as enterprises signing the contract price confidentiality clause, which aims to reduce fairness concern of the subcontractor. The results of this paper can not only enrich the research content of construction supply chain management, but also provide references for the government to formulate emission reduction policies.

A Dynamic Just-in-Time Component Delivery Framework for Off-Site Construction

Off-site construction entails various advantages compared with the traditional construction method; however, the fragmentation of the prefabrication and assembly results in a complex supply chain. Both general contractors and factories often encounter production deviation, making the original component delivery plan nonoptimal. Traditionally, both parties tend to rely on internal resources or third-party resources to manage schedule changes, paying little attention to the optimisation of the component delivery process. The static compensation mechanisms reported in existing literature require factories to manage demand fluctuations but fail to encourage general contractors to control schedule deviations. Therefore, a dynamic compensation mechanism is proposed to achieve just-in-time component delivery, with which a factory shares possible changes for each component’s delivery date to its clients on an inverse Kanban system. First, unfavourable changes for the factory schedule are allocated with surcharges, and the general contractor should compensate the factory if it accepts the date changes; secondly, schedule changes that are beneficial for the factory are assigned as incentives, and the general contractor receives the factory’s incentive upon agreeing to the changes. Based on these two scenarios, genetic algorithm-based optimisation models are developed to achieve optimal delivery planning solutions. General contractors can obtain an optimal component delivery date to reduce the additional cost when they have changed the assembly schedule. General contractors can also optimise their component delivery schedule to trade their duration flexibility for incentives offered by factories. The models can help both parties to reduce component delivery waste when either side has the motivation to change the original component delivery schedules.

THE ECONOMIST AS SCIENTIST, ENGINEER, OR PLUMBER?

Some well-known economists suggest that a good economist should act like an engineer, a surgeon, a dentist, or even a plumber. These metaphors are useful in helping economists reflect the nature of economics and their role in society. But which is the most sensible one? This paper argues that economists should be playing all these roles and more, because economics is not a single entity, and each entity has separate goals, methods, and boundaries. To take this multiplicity of roles into account, this paper argues that in addition to the traditional boundary that delineates the disciplinary domain of economics against other sciences, an overarching boundary between economic science and applied policy needs to be recognized. It then examines Esther Duflo’s “economist as plumber” metaphor and suggests that a better metaphor for Duflo’s purpose would be “general contractor,” a metaphor that, if accepted, would suggest radical change in training applied policy economists.

The Economist as Scientist, Engineer or Plumber?

Some well-known economists suggest that a good economist should act like an engineer, a surgeon, a dentist, or even a plumber. These metaphors are useful in helping economists reflect the nature of economics and their role in society. But which is the most sensible one? This paper argues that economists should be playing all these roles and more, because economics is not a single entity, and each entity has separate goals, methods, and boundaries. To take this multiplicity of roles into account this paper argues that in addition to the traditional boundary that delineates the disciplinary domain of economics against other sciences, an overarching boundary between economic science and applied policy needs to be recognized. It then examines Duflo’s economist as plumber metaphor and suggests that a better metaphor for Duflo’s purpose would be “general contractor”, a metaphor that, if accepted, would suggest radical change in training applied policy economists.

CREATING A BUILDING INFORMATION MODEL IN A SHARED DATA ENVI-RONMENT

The article presents the principles of joint work of subcontracting design organizations on the information model of the capital construction object. The organization of the general data environment developed by the general contractor is described. The tasks of the BIM manager, the optimal folder structure, and the levels of access to the information model of the participants in the design process are described.