Four-dimensional (4D) models link three-dimensional geometrical models with construction schedule data. The visual link between the schedule and construction site conditions is capable of facilitating decision making during both planning and construction stages. The emphases of these 4D developments have often been placed at the level of construction components. Practical features assisting site management are at times lacking in the following areas: generation of site usage layouts; estimation of quantities of construction materials; and, cost evaluation. In order to pinpoint the above deficiencies, the objective of this work is to enable visual study of the effects of job progress on the logistics and resource schedules. This paper presents a 4D visualization model which is intended both to help construction managers plan day to day activities more efficiently in a broader and more practical site management context, and to thereby add to our knowledge and understanding of the relevance of modern computer graphics to the responsibilities of the construction site manager. A brief site trial of the software is described at the conclusion of the paper.

With the increasing complexity of modern construction projects, there is a pressing need on higher degree of assistance from computer in order to accomplish effective planning and management. This paper delineates the previous development and implementation of a prototype four-dimensional Site Management Model (4DSMM), with the objectives to address the requirement for linking scheduling data to a three-dimensional computer graphics building model and to furnish the capability for planners to view graphic simulations of the construction process at any prospective specified date. Through the development and various real site trials in these few years, this prototype model extends 4D technology into areas of resource management and site space utilization, in addition to planning of building construction solely. In this study, a new information system platform, Graphics for Construction and Site Utilization (GCPSU), has been developed to implement the model 4DSMM. The characteristics of the prototype system, including the integration of dynamic resource management at the project level and decision-making support, and the underlying techniques, employed in the model to facilitate and tailor the construction management practice, are presented.

With the amount increasing, the BIM (Building Information Modeling or Building Information Model) data exchange and sharing face a series of challenges including integration of disparate data models, fast information extraction and data consistency maintenance. Since the existing BIM data storing and transferring method based on neutral files or a centralized database cannot meet the above-mentioned requirements, a framework of distributed BIM service on a private cloud platform was proposed. By this BIM service, multi-stage participants store relevant data on their own servers, which are virtually integrated through a CC (cloud computing) platform to form a logically complete BIM. It supports participants to establish, manage and transfer consistent BIM data efficiently with ensuring of data privacy. To achieve this BIM service, a BIM integration and service platform (BIMISP) based on IFC (Industry Foundation Classes) and CC was developed. Proved by experiments, the research achievements are useful for improving the efficiency and quality of information extraction and delivery, ensuring the safety and legality of data sharing during building lifecycle.

During the last decade, extensive research efforts have been made on the development of 4-dimensional (4D) models (space + time) which integrate computer graphics of 3-dimensional (3D) geometrical models to scheduling data with a view to generating graphic visualization of construction processes for planning and decision making purposes. Nevertheless, these 4D applications to construction planning are often limited to the component level of a building. Their major drawback is the lack of pragmatic site management features, such as analysis of resource requirements for individual construction activity, generation of site facility layouts, quantification of construction materials and cost evaluation over a specified time period. The objective of this study on 4D graphics for construction planning and site utilization (acronym 4D-GCPSU) is mainly to furnish a solution to the aforementioned problem. In this paper, our works on 4D model in a broader site management context aiming to assists planners to deal with day to day activities are delineated. The prospective requirements for 4D application to support practical use on site management are also highlighted. Keywords:3D geometrical model, 4D visualization, construction planning, construction scheduling, site management, site utilization Introduction It is generally recognized that, amongst other factors, thorough planning and efficacious site utilization are of utmost significance in the site management of building as well as civil engineering construction. Nowadays the nature of the project is becoming increasingly complex, involving more and more parties. As such, a more stringent standard on planning and communication is entailed. Up to the present moment, the stipulations of a typical building construction project are conveyed to the successful contractor mainly through paperbased working drawings. The planning staff of the contractor are often required to interpret these working drawings to formulate a project schedule relating various types of construction activities under the project. In doing so, the planners have to consider the resources requirements including human, material, plant as well as site facilities incurred under the project. They have to incorporate in their mind appropriate workspace logistics, logical construction sequence, and economic resources utilization within a spatial and time domain.Moreover, although the site organization and usage plan is largely dependent on the construction schedule, these site layout drawings are often only prepared at the inception of the project and then not updated any more to reflect the dynamism on site. As such, they are virtually separated from the planning and scheduling system. On the other hand, construction plans generated mainly by computer-based tools are usually represented as bar charts or critical path method network charts. These types of tools are not capable to display the spatial construction features as well as the pertinent resource and workspace requirements, which are envisioned ...