Environmental Protection

New Dimensions in Design

3-D Building Information Modeling offers more than a better visual

Facility designers traditionally have used two-dimensional (2-D) drawings to illustrate plans, sections, and associated information to their clients.

This format requires reviewers to have strong visualization skills. It often lacks sufficient detail in the early stages, giving reviewers little to comment on until the drawings are nearly complete. By that time, changes are costly and time-consuming. Two-dimensional drawings also fall short in properly communicating compact technologies, such as membrane bioreactors (MBRs), which can increase design complexity and the potential for interferences. When three-dimensional (3-D) modeling initially was applied to projects, facility designers used it to visualize concept layouts and structures and agree on an overall plant layout. Following an agreement, designers completed the work using the two-dimensional drawing approach.

National BIM Standard Definition Of BIM— buildingSMART A Building Information Model (BIM) is a digital representation of physical and functional characteristics of a facility. As such, it serves as a shared knowledge resource for information about a facility forming a reliable basis for decisions during its lifecycle from inception onward.

A basic premise of BIM is collaboration by different stakeholders at different phases of the lifecycle of a facility to insert, extract, update, or modify information in the BIM process to support and reflect the roles of that stakeholder.

The BIM is a shared digital representation founded on open standards for interoperability. The National BIM Standard is part of the global buildingSMART Information Delivery Manual Initiative.

Enter BIM 3-D
Still another dimension was needed, and the Building Information Model (BIM) 3-D has now provided that. This newer design tool captures facility information from smart 2-D drawings, three-dimensional models (3-D), and other information (typically manually entered data).

BIM 3-D is a major step forward, because it integrates multidiscipline design, visualization and drawing production, yet still allows designers to extract 2-D plans and sections for contract purposes.

Other benefits include: n favorable design costs; n simplified identification of conflicts and interferences among piping, structures, and equipment (from process mechanical, HVAC, structural, architectural, and electrical); and n assurance that the final drawings are coordinated without conflicts or superseded information.

Taking a virtual “walkthrough” of a proposed water or wastewater facility helps designers, owners, plant staff, regulatory agencies, or contractors clearly see the layout and function of the various aspects of the facility. Once the model is complete, construction drawings can be extracted in a 2-D format for contractors, who, if they so desire, also can review the 3- D version to better understand certain aspects. BIM includes 3-D modeling but emphasizes collaboration and provides additional information to deliver a more comprehensive facility.

Intelligent drawings
When instrumentation and control designers use Intelligent Process and Instrumentation Drawings, information can be integrated with BIM and manual data. The model enables the use of interference detection software and has the ability to generate fully dimensioned isometric drawings of piping with bills of materials/material take-offs for mechanical components. It also allows quantity takeoffs of building components. Nondesign information, such as cost calculations, energy simulations, or building code checking, can be incorporated. The model can provide the instant renderings and photorealistic images common to 3-D visualization models but with specific design details shown rather than an artist’s rendering.

CH2M HILL, a full-service engineering, construction, and operations firm, has been using BIM 3-D to deliver civil, water, wastewater, industrial, and building projects since the late 1980s. Recognizing great benefits for clients and project design, the firm developed a standard approach to delivering BIM. Routine use of this process has increased design efficiency, created a library of models that can be adapted to future needs and, on each project, created renderings and images that facilitate and enhance client and regulatory review, because they promote faster understanding.

Water reclamation facility
In a recent project, a CH2M HILL design team used BIM 3-D to solve a visualization problem in Henderson, Nev.

Henderson, a Las Vegas suburb, has experienced rapid growth over the last 10 years. That growth has meant that current capacity was lacking in the interceptor sewers conveying wastewater from West Henderson to the main water reclamation facility. In addition, reclaimed water from the facility needed to be pumped back to West Henderson, requiring significant power. The city opted to build a satellite water reclamation facility in West Henderson to save about $5 million in projected annual costs.

Summary of BIM Features and Benefits

BIM creates the capability to retrieve intelligent data and facility images throughout the project’s lifespan, providing significant value and return on investment.

Project stakeholders achieve greater understanding through 3-D virtual “walkthroughs” of the new facility, at all stages of the design process, leading to earlier and higher quality decisions.

Improved design quality (interference checking, extracted drawings), combined with the inclusion of all design disciplines, decreases the risk of error and cost overruns.

Questions during construction can be answered by viewing the model with the construction contractor. This helps to explain design details that may not be understandable or shown in 2-D drawings.

Designs and costs are optimized, including the use of simulation and analysis tools.

BIM accommodates a variety of traditional and alternative delivery approaches.

Capital cost estimates can be made by extracting quantities from the project database and applying local or national cost multipliers. Quantities are categorized by the data housed within the model, so the database knows what material a building component is, or what material and flow stream is associated with a pipe. The effort to produce capital costs have been reduced more than 30 percent because of the availability of the project database.

The Southwest Water Reclamation Facility is designed to remove wastewater from the collection system and to supply water into the reclaimed water distribution system. The design team completed the facility planning, predesign, and final design for an 8-milliongallon- per-day (mgd) average daily flow facility and potential expansion to 16 mgd using MBR technology.

The facility design began with 3-D modeling during the schematic phase. The team created models for each facility, providing an integrated approach. Each discipline worked within the facility-specific models to develop key parts of the design. The team located major piping, ductwork, electrical “right of ways,” structures, and equipment within the models, creating an overall model reflective of the sizing and facility layouts. Utility Services Department engineers and operators viewed that model for the schematic design review to finalize key decisions.

The team further developed the facility models, all in 3-D, during the remaining design phases. At planned milestones, traditional 2-D drawings were extracted and submitted to the client. Then, the team held detailed design reviews for each 3-D facility model, working through the facilities with the client from a flow-path perspective. The team also provided renderings within the design drawing sets to help reviewers visualize the facilities.

By integrating each facility model and the site work into a common model using InRoads software, the overall model was animated to show a 360-degree flyover of the facility. The ability to perform design reviews while working through the 3-D models allowed a significant change in the review process. Instead of having to search through 500 multidisciplinary drawings, the client was able to view all disciplines in the live model reviews, providing a valuable interactive approach to the design process and client input to key decisions.

The use of 3-D and BIM is now CH2M HILL’s most efficient method of project delivery. The actual evolution of the design models allows each discipline to work together in the same model, enhancing coordination and limiting the potential for rework. As the library of projects grows, base models become available for specific unit processes that can be considered “templates” for future designs. This approach now is being used for water and wastewater treatment plant design projects in all parts of the world.

3-D/2-D or BIM 3-D— What’s the Difference?

3-D/2-D
• Designers create 3-D visualizations of the plant layout concept
• Once the layout is agreed upon, 3-D work stops
• The design is completed in 2-D

BIM 3-D
• Designers create 3-D visualizations of the plant layout concept
• Once the layout is agreed upon, multidisciplinary design is completed within an integrated 3-D model
• 2-D plans and sections are extracted from the 3-D model for contract drawings
• Accurate and comprehensive representation of information
• Model components linked to information databases
• Useful across project lifespan

This article originally appeared in the 12/01/2007 issue of Environmental Protection.

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