HomeNewsNewsletterArchivesAuthorsJobsVideoDirectoryTwitterEvents
Register to receive the LiDAR MAG Newsletter  
advertisement

eNewsletter

News

remove subscribe

LiDAR Magazine Today


 

follow us on Twitter 

Sponsored By


TAS Lidar Content
TAS Content
Videos
Meet the Authors
Check out our fine lineup of writers. Each an expert in his or her field.
Sponsored By


Partner Sites

American Surveyor

machinecontrolonline 

lbszone.com

GISuser.com

GeoJobs.biz

GeoLearn

 

Spatial Media LLC properties

Associates

ASPRS

Connect

LinkedIn Group
twitter
youtube
facebook group
rss

  LiDARmag     

Rapid-Response UAS Keeps Construction on Schedule and Prevents Earthwork Overages Print E-mail
Written by Christian Stallings   
Wednesday, 25 October 2017

A 2.991Mb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

On a large development site, slight discrepancies in elevation can throw off earthwork volume estimates by tens of thousands of cubic yards. What looks small on paper becomes massive in the field.

McKim & Creed—an ENR Top 500 engineering, surveying and planning firm—faced this situation when verifying elevations in Briar Chapel, a 1,600-acre master planned community in Chapel Hill, North Carolina. Developed by Newland Communities, Briar Chapel is one of the largest green residential communities in the Triangle (Raleigh/ Durham/Chapel Hill) area. McKim & Creed is providing civil / site engineering and surveying services for the community.

Last spring, when the initial clearing was completed on a 25-acre commercial site within Briar Chapel, McKim & Creed surveyors were called in to verify elevations. An aerial photogrammetry survey of the entire community site had been conducted by another company several years earlier, and McKim & Creed needed to verify the accuracies. "As we prepare engineering design on each individual phase of the project, we have our survey crews do field checks of spot elevations to make sure the current grades still match the old survey," explained Chris Seamster, RLA, McKim & Creed's project manager for Briar Chapel.

In their field checks, the surveyors discovered some variances, ranging from a few inches to over a foot, between their data and the existing aerial survey. "The discrepancies were not consistently low or high; they were just varied," Mr. Seamster commented. "The original aerial survey was done with full tree cover, which can sometimes skew survey data. In the other company's defense, it was probably within their contracted tolerance."

Even so, once construction began the slight differences on paper could quickly turn into mountains of wasted dirt. For Newland—a leader in sustainability, green building and open space—waste is not an option.

Because construction was imminent, the team needed a quick, reliable and cost-effective way to verify the elevations. Flying the site again would take too long and be too expensive. "The main things were time and the ability to provide quick results," said Mr. Seamster.

That's when the idea to use unmanned aerial systems (UAS), also known as drones, took off. UAS achieves the 5-cm data accuracy of aerial photogrammetry, but data can be collected much faster and more costeffectively on sites that are less than one square mile. "We saw an opportunity to try out drone capabilities in our type of industry. In our partnership with McKim & Creed, we were trying to find another way to be more efficient, manage the whole design-build process, and be integrative. Hopefully it would be quicker," said Lee Bowman, senior project manager with Newland.

McKim & Creed's UAS team quickly deployed to the site, and a full survey of the site was performed within a few hours. The next day, Newland was presented with an updated survey CAD file of the topo, a high-resolution ortho photo, a classified point cloud of the bare earth, and a change detection analysis to compare the two surveys. The earthwork estimates were adjusted as needed and construction commenced on schedule, with no wasted time, money or fill.

"UAS is increasingly becoming a very attractive tool for land development. The conditions are ideal because there are no features to obstruct the surface, and we can easily conduct repeat visits to monitor progress," explained Mr. Seamster.

Concluded Mr. Bowman, "Getting the information that fast saved us money in the end."

Christian Stallings, CP, is responsible for overseeing LiDAR production operations at McKim & Creed, Inc. He holds a master's in geographic information technology and a graduate certificate in remote sensing from Northwestern, and extensive instruction in advanced LiDAR data processing and advanced production workflow from Penn State.

McKim & Creed is an employee-owned engineering, surveying and planning firm with more than 400 staff members in offices throughout the U.S., including North Carolina, Florida, Virginia, Georgia, Texas, and Pennsylvania. McKim & Creed specializes in airborne and mobile LiDAR/scanning; unmanned aerial systems; subsurface utility engineering; hydrographic and conventional surveying services; civil, environmental, mechanical, electrical, plumbing, and structural engineering; and industrial design-build services for the energy, transportation, federal, land development, water and building markets. For more information about McKim & Creed, visit www.mckimcreed.com.

A 2.991Mb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

 
< Prev   Next >

 

Share this page with your favorite social networks! 

deliciousrssnewsletterlinkedinfacebooktwitter

LiDARmag Exclusive Online-only Article ticker
Featured LiDAR MAG Events
List Your Event Here
please
contact LiDAR

Google
 
LiDAR MAG TOP NEWS


FARO Intros
SCENE 7.1

GOT NEWS? Send To
press [at] lidarmag.com
Online Internet Content

Sponsor


White Papers
Careers

post a job
Reach our audience of Professional land surveyors and Geo-Technology professionals with your career ad. Feel free to contact us if you need additional information.

News Feeds

 
Subscribe to LiDAR MAG updates via friendfeed

Need Help? See this RSS Tutorial






©Spatial Media LLC - All rights reserved / Privacy Statement
Spatial Media LLC
905 W 7th St #331
Frederick MD 21701
301-620-0784
301-695-1538 - fax