CAD and Management of Construction Projects

The increasing interest in computer‐aided design (CAD) has prompted research that is aimed at identifying the opportunities for construction managers and building contractors. It has been found that the use of CAD systems in the U.K. is mainly confined to the production of detailed drawings. Indeed, most of the systems used are 2‐D drafting tools and incapable of supporting the integration of even modest amounts of nongraphical (construction) data. On the other hand, many 3‐D modeling systems have the potential to integrate construction data, although they appear to be almost ignored. The use of 3‐D modeling systems is considered to be the most suitable vehicle for successfully integrating these data. However, this is likely to necessitate the introduction of separate databases, preferably of the relational type. The use of 3‐D modeling systems in assessing the construction implications of outline designs also presents interesting possibilities and is discussed.     

Mixed Reality-Based Visualization Interfaces for Architecture, Engineering, and Construction Industry

Varied computing devices and automated sensors will enable new human-computer interface paradigms for interacting with digitally managed project information. The writers therefore propose the development of Mixed Reality (MR)-based computer interfaces, and especially Augmented Reality systems, for the architecture, engineering, and construction industry and describe the technologies and principles for applying such computer interfaces to support all phases of the constructed facility project life cycle. An Augmented Reality computer-aided drawing prototype is described as an experimental platform to study the human factors issues in interacting with Augmented Reality three-dimensional digital design models. Two critical research needs are cited for realizing effective Augmented Reality systems: (1) human factors research for development of visualization tools to enhance design comprehension and support collaborative work, and (2) the development of a technology infrastructure for “augmented” control and inspection interfaces to directly access digital project plan and site information that may be spatially referenced and displayed in the field. Research should be geared to advance knowledge regarding spatial cognition, human–computer interfaces, and computer-mediated human-to-human interactions, and it should address application of MR to all phases of the project life cycle.     

Application of Small Computers in Construction

The deliberations of the ASCE Task Committee on the Application of Small Computers in Construction are presented. The paper first identifies needs that are stimulating the application of small computers in construction, and then examines their present and potential utilization in several representative application areas. Applications include accounting and payroll, estimating, field office administration, contract language retrieval, electronic communications, scheduling, process simulation, graphical reporting, computer‐aided design, and process control. The role that ASCE might take in supporting the effective application of small computers in construction practice is considered. Possibilities include participation in the development of standards, education of practitioners, stimulation of innovative techniques, liaison with other organizations, input to computer manufacturers and software developers about specific needs and requirements in construction, studying the organizational and behavioral aspects of computers in construction, and input to ASCE awards committees about meritorious work in this area. It is concluded that an ongoing ASCE Construction Division committee is needed to monitor and influence the effective application of this rapidly evolving small computer technology in construction.     

Construction Scheduling and Progress Control Using Geographical Information Systems

Traditional scheduling and progress control techniques such as bar charts and the critical path method (CPM) fail to provide information pertaining to the spatial aspects of a construction project. A system called PMS-GIS (Progress Monitoring System with Geographical Information Systems) was developed to represent construction progress not only in terms of a CPM schedule but also in terms of a graphical representation of the construction that is synchronized with the work schedule. In PMS-GIS, the architectural design is executed using a computer-aided drafting (CAD) program (AutoCAD), the work schedule is generated using a project management software (P3), the design and schedule information (including percent complete information) are plugged into a GIS package (ArcViewGIS), and for every update, the system produces a CPM-generated bar chart alongside a 3D rendering of the project marked for progress. The GIS-based system developed in this study helps to effectively communicate the schedule∕progress information to the parties involved in the project, because they will be able to see in detail the spatial aspects of the project alongside the schedule.     

Constructing a Complex Precast Tilt-Up-Panel Structure Utilizing an Optimization Model, 3D CAD, and Animation

This paper presents the concept used to construct a complex residential tilt-up-panel structure utilizing three-dimensional (3D) modeling and animations. The residence comprises of 108 precast concrete panels of varying rectangular shapes with “dog legs” and window and door “cutouts” that look like an assembled jigsaw puzzle. The erection and installation procedure called for a maximum panel-to-panel joint tolerance of 1.27?cm (0.5?in.), often in 90° joints between panels. 3D animations were used to experiment with the construction process on the computer screen prior to construction in order to avoid potential costly on-site errors. In addition, the 3D animations were also used as a training tool for the contractors. This paper focuses on describing the methodology used to integrate a crane selection algorithm and optimization model with 3D modeling and animation for the selection, utilization, and location of cranes on construction sites. Analytical optimization processes were used to decrease the traveling time and distance of the selected crane, to improve the crane lifting sequence and to minimize the use of panel casting slabs.     

Evaluation of Student Learning for an Engineering Graphics Course

The ability of students to master various skills defined by a set of course learning objectives of an engineering graphics course at San Jose State University was assessed. One semester offering of the introductory course was reviewed. The course objectives were evaluated by the amount of coverage each received on the exams and the level of cognitive skill required according to Bloom’s Taxonomy. Student learning was assessed by review of their ability to produce documented evidence of mastering the skill. In addition two methods of assigning grades based upon student performance were compared. The primary finding of the study was that the ability of students to master particular skills varied widely on both objectives and taxonomy levels. Secondary findings were that the exams did not address each objective equally, and that some important objectives did not receive the coverage they likely deserved. Recommendations about improved wording of some objectives were made to more clearly state the instructor’s intent. The grade assigned to a student would have been different depending upon the method the instructor uses for evaluating their score for an exam. If scoring is weighted based upon the taxonomy level, then some students would receive higher grades while others would have been lower. The distribution of points received for exam questions covering objectives of different taxonomy levels showed that C-students generally performed poorer than A-students, but that at some levels performed better.     

Enabling More Human-Oriented Exploration of Complex Building Information Models

Building-related information is captured and has to be reused throughout the entire building life cycle. Therefore, an intuitively understandable and easy-to-handle access to a building life cycle wide archive is essential. Cross-disciplinary information seeking should be possible based on a three-dimensional representation of the building. In information seeking the planner must not be restricted to a single searching strategy. This paper initially focuses on all supporting explorative searching strategies. A “raw” building information model schema has been enhanced by user-oriented associations between particular data objects, referred to in this paper as “navigation links.” Each link is defined as a new property of a particular concept of the building model schema. Such a link points to a query recipe that can retrieve information about each instance of the concept. If the link is activated by a user, the query recipe is instantiated and processed by the system. The navigation links are formally represented using the Web Ontology Language. This paper describes the structure of the links as well as the structure of the system, which stores and processes the links throughout an information-seeking session.     

Implementing a B2B e-Work System to the Approval Process of Rebar Design and Estimation

In reinforced concrete construction, it is still common for rebar suppliers to accept computer-aided design (CAD) drawings and then generate new drawings for the shop floor, which ultimately are presented to the contractor as blueprints. In other cases, rebar suppliers accept hard copies of blueprints and return CAD files featuring different design layers and elements. Under this arrangement, communication between project participants is fragmented and depends solely on the direct input of the participants in a specific task. This paper proposes a business-to-business (B2B) e-Work system to improve the approval process for rebar estimation data. This system is composed of extensible markup language-based databases that support essential tasks of the approval process such as design and revision of structural drawings, bidding, shop drawing preparation, revision, and correction, and rebar delivery. The performance of the proposed system is compared with existing industry practices based on data obtained from structural designers, contractors, and rebar suppliers.     

Web-Services Environment for Collaborative Management of Product Life-Cycle Costs

There is an increasing need for effective tools for managing life cycle costs (LCC) of civil products. This paper presents a web-based semantic system for managing products’ life cycle costs. The basic architecture of the proposed system represents costs as a hierarchy of cost elements. Each cost element has a dollar value that could be deterministic, probabilistic, or fuzzy. Several factors (also represented in hierarchies) can have a set of impacts on the values of these costs. Through the analysis of different impact possibilities and probabilities, a decision maker can study various alternative scenarios and define the optimum set of costs and their values. A set of web services are used to capture cost elements, factors, and their impacts. The semantic nature of the system allows for it to be an integral part of a corporate memory system, where decision makers will be able to document and access lessons learned about LCC optimization. Finally, the proposed system includes a framework for a LCC-centered supply chain, where all stakeholders can collaborate in optimizing product LCC.     

Integrated Model for Optimizing Strategic Overhaul Planning of Distributed Pump Stations

An important part of the lifecycle costs for pump stations are the support costs associated with energy and preventive maintenance of the pumps. Both cost terms are interrelated because a trade-off exists between maintaining pumps frequently (with increased pump efficiency, reduced energy costs and increasing maintenance costs, and pump unavailability) and extending the intervals between the overhauls (increased loss of efficiency, increased energy costs, and decreased maintenance costs). The planner needs to forecast pump overhaul demands to determine budget levels because economic resources are limited. This process is assisted by using mathematical programming methods to prioritize funding for equipment requiring renewal in consideration of limited resources in a strategic time horizon (several years). This work proposes an efficient model to define an overhaul maintenance program for a pump network with a large number of pumps (a few hundred in the case study). The model minimizes the discounted total (energy+overhaul) cost by selecting and scheduling pumps for overhaul subject to budget constraints. The formulation uses 0–1 integer programming.     

江西省科技馆楼宇设备自动化系统设计概述

结合江西省科学技术馆楼宇设备自动化系统设计,阐述楼宇设备自动化系统基本概念及设计方法。     

RFID+4D CAD for Progress Management of Structural Steel Works in High-Rise Buildings

This research presents a strategy and information system to manage the logistics and progress control of structural steel works under the integrated environment of radio frequency identification and four-dimensional computer-aided design (4D CAD). Considering the characteristics of the manufacturing and erection processes of structural steel works in high-rise building construction from a practical point of view, this research has developed a strategy to support successful application of these two state-of-the-art technologies and has developed an information system to support the logistics and progress management based on this strategy. The results of this research have been validated and verified through real-world applications in two high-rise building construction projects considering realistic constraints. Time study has been conducted to verify the efficiency of the proposed information system. In addition, lessons learned and issues identified through these real-world applications are described and discussed in this paper.