AEC

Keeping the Civil Data Chain Intact

1 Jun, 2004 By: Cadalyst Staff

Object-based 3D civil software matures


WHEN PC APPLICATIONS FIRST became accessible to civil engineers and surveyors in the early 1980s, many began to seek field-to-finish solutions. Firms sought ways to collect field survey data digitally, send data to designers for use in an office setting, and then reverse the process to send design data back to the field for staking and construction.

In reality, the process has been far from seamless. Even with improved communication between field data collectors and design software, a certain amount of manual data entry or data manipulation remains necessary before designers can use the data with CAD software. Additional data entry is often required to transform conceptual designs into usable construction plans, and then to convey design information to the field.

The process is still not perfect, but the industry is closing the gap on maintaining a continuous data chain. More intelligent design software is helping the cause, as are handheld applications that provide field access to data once limited to desktop computers.

Object - based Software

Designers are often caught in the middle of the datastream, tweaking field and office data before, during, and after design. The domino effect-when a single design change affects several portions of a project-is particularly bothersome, requiring manual editing of lines, text, and other CAD entities.

Object-based software, such as Civil 3D from Autodesk ( www.autodesk.com ), helps automate this process, says James Wedding, information technology manager at Jones & Boyd, a Dallas engineering, surveying, and planning firm. With key components of land development projects represented as intelligent objects, instead of generic entities such as lines, arcs, and text, design changes are not as painful. A parcel of land, for example, is a cohesive object, with geometric characteristics and labels associated with it (figure 1). When a designer moves a lot corner, the other components of the parcel move accordingly, and the labels update automatically.

 Figure 2. Grading objects in Autodesk Civil 3D allow dynamic updating of contours, earthwork volumes, section views, and annotation.
Figure 2. Grading objects in Autodesk Civil 3D allow dynamic updating of contours, earthwork volumes, section views, and annotation.

Dynamic updating has greatly aided the development of what-if scenarios for designing land development projects, says Wedding. "The parts know they belong to each other," he says, noting that adjustments that previously took 10-15 minutes are now done instantaneously.

Civil 3D also includes objects for points, alignments, profiles, sections, and surfaces. Its grading groups provide a collection of related grading objects, allowing designers to model building footprints and easily generate proposed grading contours and section views (figure 2). If the building footprint changes, proposed contours, earthwork volumes, and other data dynamically update to reflect the change.

Figure 1. Parcel objects in Autodesk Civil 3D dynamically update lot dimensions, areas, and other data. Courtesy of Jones & Boyd.
Figure 1. Parcel objects in Autodesk Civil 3D dynamically update lot dimensions, areas, and other data. Courtesy of Jones & Boyd.

Autodesk launched Civil 3D in late 2003 as an introductory product for Autodesk Civil Design subscribers. Many features, such as the grading object, are still being refined, and Autodesk doesn't plan for it to replace the Land Desktop and Civil Design products any time soon. For now, Civil 3D will primarily be used in conjunction with Land Desktop, says Dave Simeone, Civil 3D product manager. Autodesk's development plans are still evolving, but sometime in the future, Civil 3D could encompass Land Desktop and Civil Design as a stand-alone product. The timing depends largely on how quickly the industry embraces the object-based approach. "It's a significant shift in the way our customer base has worked," says Simeone. "The market will tell us what the time-frame is."



Field Ready

As design software has matured, so have capabilities for exchanging data with field personnel. FDOT (Florida Department of Transportation), a primary user of MicroStation and GEOPAK from Bentley Systems ( www.bentley com ), has worked with Bentley for several years on streamlining processes for generating quantities such as concrete, asphalt, signage, and landscaping items to include in construction contracts. The public agency helped shape development of Bentley's Quantity Manager, a stand-alone tool that manages quantities generated by the Design and Computation Manager feature of GEOPAK.

Using Quantity Manager, FDOT eliminates most paper-based processes for documenting quantities (figure 3). The agency uses the GEOPAK Design and Computation Manager to calculate quantities based on design data and then exports them to Quantity Manager. Users can also load manually generated quantities for nongraphical elements into Quantity Manager.

Figure 3. Bentley’s Quantity Manager streamlines management of pay items during construction. Courtesy of Florida DOT.
Figure 3. Bentley’s Quantity Manager streamlines management of pay items during construction. Courtesy of Florida DOT.

FDOT and other users have also used Quantity Manager to exchange data with Trns•port, a software suite developed by the American Association of State Highway and Transportation Officials ( www.aashtoware.org ) to manage transportation projects. Users can import standard pay items from Trns•port for use in Quantity Manager, as well as the federal and state funding splits for pay item quantities on individual projects. Bentley introduced Quantity Manager for GEOPAK last year, and this year plans to release a version to complement InRoads, Bentley's civil engineering suite that works with MicroStation and AutoCAD.

Staking and Inspection

Agencies are also trying to maintain the data flow into construction staking and inspection. Bentley developed handheld applications that MnDOT (Minnesota Department of Transportation) has used to stake storm drainage structures and other project components (figure 4, p. 47). Users can import design data from GEOPAK, display drawings on a handheld device, and select items to be staked. Linked with a GPS (global positioning system) or ground-based surveying equipment, the handheld application calculates cut and fill information as well as pipe slopes and other data, says Dean Bowman, director of development for Bentley civil software. Traditionally, drainage structures that connect multiple pipes require a plethora of field measurements and manual calculations to establish stakes and stringlines for each pipe, he says.
Figure 4. Bentley’s handheld applications linked with GPS can reduce steps in staking drainage structures.
Figure 4. Bentley’s handheld applications linked with GPS can reduce steps in staking drainage structures.

Bentley also developed a handheld inspection module that helps automate data gathering, calculations, and input processes for field inspectors. Again using design data imported from GEOPAK, inspectors can select a plan item, determine its calculated quantity, and then enter a field-measured quantity for comparison along with a variety of other inspection information (figure 5). Because inspection reports are stored in a database, inspectors can also access compilations of previous inspection data while in the field. Traditionally, inspection data is recorded on paper and typed into electronic forms, which are not easily accessed in the field. Using an XML (extensible markup language) schema, users can also export this data into Trns•port.

 Figure 5. During inspection, measurements made by GPS or by specifying station/offset locations are depicted graphically and represent as built conditions in Bentley’s handheld application
Figure 5. During inspection, measurements made by GPS or by specifying station/offset locations are depicted graphically and represent as built conditions in Bentley’s handheld application

MnDOT used the Bentley handheld applications last year in a pilot study and is using them this year on actual projects. Bentley plans to release the products commercially in 2005, says Bowman. Autodesk and other vendors also have a variety of handheld applications on the street and under development.

Changing Landscape

As with most other business sectors, the civil engineering software landscape has been heavily shaped by mergers and acquisitions in recent years. After acquiring Intergraph's InRoads product line in 2001, Bentley last year bought Infrasoft and its MX line of products, which work with both AutoCAD and MicroStation. For the near future, all three products will be maintained, says Randy Tardy, Bentley's industry director for transportation.

In 2002, Autodesk acquired CAiCE Software Corp., a Florida-based developer of transportation design software. Autodesk plans to continue support and maintenance for CAiCE products with regular service packs, but currently has no plans to provide any new features or enhancements to the products moving forward, says Mathews Mathai, CAiCE product manager. "Our present plans focus on integrating key CAiCE technologies into Autodesk Civil 3D software," he says.

Though other civil engineering software vendors dot the landscape, Autodesk and Bentley continue to reign as the key players, with their respective DWG and DGN file formats often the focal points of project delivery. Regardless of drawing format or software vendor, the common theme of maintaining a continuous data chain is taking hold. Industry professionals can expect to see more data reuse and less data recreation-a welcome goal for all


About the Author: Cadalyst Staff

Cadalyst Staff

AutoCAD Tips!

Lynn Allen

Autodesk Technical Evangelist Lynn Allen guides you through a different AutoCAD feature in every edition of her popular "Circles and Lines" tutorial series. For even more AutoCAD how-to, check out Lynn's quick tips in the Cadalyst Video Gallery. Subscribe to Cadalyst's free Tips & Tools Weekly e-newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!
Follow Lynn on Twitter Follow Lynn on Twitter


Poll
Which file format do you use most often for CAD drawing/model exchange?
Native format
PDF
3D PDF
DWF
STEP or IGES
JT
IFC
Other
Submit Vote