CADD Integration and Applications during Construction
L. Y. Liu,* A. Stumpf* (CERL)
U.S. Army Construction Engineering Research Laboratories

This project explores the application of CADD to construction simulation/animation and the integration with construction specs, schedule, costs, as-built, QA/QC guidelines, and biddability/constructibility/operability database.

Construction Object-oriented Process Simulation
L. Y. Liu*
University of Illinois

Simulation provides a practical means of analyzing construction processes to identify resource utilization and idleness, operation bottlenecks, productivity, and opertional costs. This research uses object-oriented programming to design a network-based discrete-event simulation system for construction process modeling. All modeling elements are implemented as objects with integrated functionality of interactive computer graphics and simulation. Models are constructed through a friendly graphical user interface. Simulation is accomplished by active objects sending messages to one another. This paradigm of simulation system design can provide many advantages over traditional design, such as realistic resource tracking, precise simulation control, and linkage with other knowledge-based expert systems.

Construction Risk Management
L. Y. Liu,* G. Rao
University of Illinois

This research develops a synthesis approach to manage construction risks for environmental remediation projects. A method is developed to extract information from historical data to assist project managers in identifying risk components that deserve additional attention and analysis. AHP (analytic hierarchy process) techniques are used to aggregate factors and preferences for decision making.

Construction Site Digital Data Collection Devices
L. Y. Liu*
University of Illinois

This project develops a hardhat-mounted device that collects multimedia information including video and sound for construction inspection and documentation. The device uses voice-activated control and allows construction inspectors to walk hands-free at the project site to document site conditions or problems. Narration, pictures, and videos can be taken and stored digitally into the device and can later be ported into a database that supports project control and documentation. A heads-up display is used for synchronizing the camera direction with the eyes. This device allows wireless two-way communications where images can be transmitted to and from the host computer.

Construction Time/Cost Trade-Off Decision Support
L. Y. Liu,* S. A. Burns* (Gen. Engr.)
University of Illinois

Construction engineers face the challenge of selecting the most effective construction methods for tasks within a project. Different methods, equipment, and crew sizes can be chosen for tasks depending upon the contract time limit and budget. Not all tasks are of equal importance in a project. Some tasks carry floats and can be delayed without impacting the project duration. Some tasks are critical because any delay on those tasks delays the project. Construction engineers may choose alternative construction methods, smaller crew sizes, and less productive equipment at lower costs while maintaining the same project duration. The purpose of this research is to develop a generic algorithm for assisting construction engineers in selecting optimal time/cost strategies to complete a project.

Environmental Remediation Project Documentation Using Multimedia Technology
L. Y. Liu,* A. Stumpf* (CERL)
U.S. Army Construction Engineering Research Laboratories

This research project applies multimedia technology to store text, photos, sound, and video information with project schedule activities for environmental remediation projects. Construction project progress can be tracked and evaluated visually with computer-integrated site condition photos and videos. The site condition information can be transmitted back to experts at the headquarters through computer networks. This system allows more complete documentation of construction progress, problems, and innovative ideas. In addition, in claims and disputes, all parties' rights can be better protected by hard facts, not by the capability of the legal consultants.

Hierarchical Project Information Documentation
L. Y. Liu,* A. Stumpf* (CERL)
U.S. Army Construction Engineering Research Laboratories

The vast amounts of information generated during construction are a challenge to construction managers. Well-documented project information during construction not only eliminates problems in claims and disputes, it also provides a rich source for lessons learned, improvement, and innovation. This research creates a hierarchical information system that allows users to store project information or knowledge according to (1) CSI Master format or (2) a user-defined information hierarchy. In addition to hierarchical search, keywords can be used to retrieve information. All information, including text, picture/images/drawings, sound, and video, will be store digitally on CD-ROMs with full indexing and cross-referencing capability. Previous cases, problem-solving ideas, and failures can be quickly retrieved, compared, and cross-referenced.

Impact of Design and Construction Integration on Facility Delivery Process and Performance
L. Y. Liu,* J. Pocock
University of Illinois

This research investigates the impact of design and construction integration on the performance of a constructed facility and the process of delivering a facility. A quantitative model to measure design and construction integration is set up to measure the degree of integration and its impact on construction. In addition, comparisons of traditional construction, partnering, and design-built are made to evaluate the impact of contract relationships on construction time, cost, safety, and quality.

Schedule Evaluation and Reasoning Using 3-D Modeling and Animation
L. Y. Liu*
University of Illinois

Three-dimensional animated display of construction sequences facilitates nonambiguous evaluation of schedules. Potential schedule conflicts and interferences can be easily identified with the visual display. Alternative construction sequences can be simulated and compared as if a facility were being constructed in real life. The objective of this research is to use 3-D modeling and animation environments for schedule evaluation and reasoning. Information will be extracted directly from components of a design in the 3-D environment and chained with a knowledge base for schedule evaluation and reasoning.