Lingguang Song

Enhanced NURBS modeling and visualization for large 3D geoengineering applications: An example from the Jinping first-level hydropower engineering project, China

Large engineering projects with complex underlying geologic structures require 3D geological integration and analysis. Presented is an example of a large hydroelectric dam, highlighting the need for 3D visualization and modeling as a requirement for the engineering design and construction process. Due to the complex nature of these projects, geological analysis using 3D modeling is commonly necessary. In this paper we present an integrated 3D geological modeling methodology for the analysis of large amounts of exploration data, and subsequent geological interpretation based on the non-uniform rational B-spline (NURBS) technique, the triangulated irregular network (TIN) algorithm and boundary representation. The procedural details and application of the proposed approach are demonstrated with reference to an actual hydropower engineering project. The new approach offered a good scheme to solve the inconsistencies among storage, accuracy and operational speed of the model. A 3D model was developed and validated using testing data from the engineering project. Visual analysis of the 3D model helps engineers to comprehend the complexity of geological structures, and enables arbitrary cutting, rock-mass quality classification, and digital drilling.

A framework for real-time simulation of heavy construction operations

This paper describes a framework of real-time simulation for modeling heavy construction operations. Compared with the traditional offline simulation that uses stationary inputs, the capability of real-time simulation to dynamically incorporate new project data and adapt to changes in the operating environment offers the promise of improving the accuracy of project forecasting. In the proposed real-time simulation framework, dynamic data from construction operations are constantly captured and fed into a process-simulation model for short-term scheduling purposes. A prototype system was developed to demonstrate the structure of the proposed framework and its feasibility. The benefits of this simulation approach and future research requirements for achieving a higher-level modeling automation are also discussed in this paper.

A virtual shop modeling system for industrial fabrication shops

Abstract Industrial fabrication is both a production system with a high product mix and a project-based industry. The accuracy of short-term project-based planning, such as estimating and project scheduling, is extremely important for a project’s success. This paper proposes an integrated modeling system that explicitly models the product mix in order to improve the planning accuracy. Automated process planning and a processing time estimation method were implemented through the integration of simulation with such modeling methods as computer aided process planning and artificial neural networks. Two case studies are presented to demonstrate the capability of the proposed system.

Measuring and Estimating Steel Drafting Productivity

This paper describes an engineering productivity measurement system and proposes a neural network modeling approach for estimating the engineering productivity. The methodology has been applied to steel drafting. Firstly, the research focused on measuring the work scope of steel drafting projects. A method of quantitatively measuring the work scope was developed based on installed quantities, which is the quantity of steel pieces in terms of their physical characteristics. With the developed consistent measurement standard, a neural network model for estimating drafting productivity was developed and implemented using influencing factors appropriate to project conditions. Historical data collected through an implemented data acquisition system in a steel fabrication company were prepared for neural network training and model validation. This predictive model streamlines and increases the accuracy of earlier estimating process, which was highly subjective.

Photo-modeling for Construction Site Space Planning

Space planning of complex and congested construction sites affects construction safety and field performance. The traditional method of relying on visual inspection and 2 dimensional (2D) drawings for layout planning is limited by the fact that construction sites are usually highly complex and dynamic. Existing site conditions must be frequently captured to represent its latest status for space planning. Recent development of 3 dimensional (3D) reality-capturing technologies, such as laser scanning and photo-based modeling, allows an accurate measurement of a job site and its representation in a 3D format. This research proposes a photo-modeling approach for capturing as-built conditions for space planning purposes. This technique automates the reality-capturing process in which a series of 2D photos taken from different perspectives are used to derive an as-built 3D model of a construction site. The feasibility and effectiveness of the proposed approach is demonstrated in an industrial case study.

Building a virtual shop model for steel fabrication

Steel fabrication is a complex process, which encompasses product uniqueness, a high product mix, and a number of activities involving a variety of equipment and labor disciplines. The steel fabrication industry needs advanced tools and techniques in order to estimate, plan, and control fabrication shops. We propose a system for building virtual fabrication shop models capable of estimating, scheduling, and analyze production. The system defines conceptual models for product, process, and the fabrication facility itself. It offers tools, such as product modeling, process modeling and planning, and a special purpose facility modeling tool, which allow users to implement these conceptual models. Modeling enhancements have enabled a more accurate modeling of machine and labor productivity, as well as better management of shop production rules. The modeling capability of the developed system is demonstrated through a case study.