LiDAR Offers Increased Accuracy, Safety to Structure Condition Assessments

Freese and Nichols has added the use of LiDAR (Light Detection and Ranging) technology for conducting structural condition assessments on lift stations, wet wells and wastewater conveyance facilities– projects that are routinely expensive and time-consuming for water utilities and dangerous for inspectors. While it is often used to assess bridges, roads, rail infrastructure, modular construction and pipelines, this new LiDAR application for water utilities originated as an internal Research and Development project led by Maziar Mahdavi, a Structural Engineer based in Fort Worth.

A 3-D interior image of this wet well provides high-resolution illustrations of any defects on the project site.

Maziar has led Freese and Nichols’ testing of LiDAR use in two separate water utility projects in North Texas – the City of Cleburne Lift Station and the North Texas Municipal Water District (NTMWD) Lift Station.

“For our utility clients facing needs assessments and upgrades for conveyance and treatment facilities, using LiDAR for structural assessments could streamline these projects, keeping cost, risk, delivery time and plant management coordination to a minimum,” Maziar said.

Stefan Malhotra, Freese and Nichols Risk and Safety Manager, praises the safety benefits of using LiDAR.

“Traditional methods for assessing confined spaces of intake towers, storage tanks and lift stations expose workers to significant safety hazards like oxygen deficiency, structural collapse and toxic atmospheres. However, using LiDAR in some of these scenarios can drastically reduce or even eliminate these hazards, allowing Freese and Nichols employees to collect their data more safely and conveniently,” he said. “That’s a win-win.”

LiDAR cameras are mounted onto a pole and lowered into the project site’s interior to capture detailed information on its structural integrity.

Benefits of LiDAR for Structural Condition Assessments:

  • Safety: LiDAR cameras remove the risk of sending humans into confined spaces to perform structural evaluations.
  • Accuracy: The technology can identify surface defects on a wet well interior as small as 7 mm.
  • Cost-effectiveness: If the post-processing of LiDAR data can be automated, costs will be further reduced.
  • Efficiency: Using LiDAR does not interrupt the utility operation and allows the project team to finalize its data faster.

How It Works:

Typical structural assessments of wet wells, for example, are completed by descending personnel into these confined spaces, which requires dewatering the well, cleaning the walls and ventilating hydrogen sulfide gas. With LiDAR, many of these risks are eliminated, and the process is improved.

The resulting imaging is precise in showing the extent of the deterioration, helping the client determine repair plans, if necessary.

LiDAR has proven to be transformative by providing high-resolution insights to structural integrity. By integrating LiDAR, Freese and Nichols aims to reduce human error and minimize the health and safety risks associated with the approach.

If you would like to learn more about LiDAR and how it can be utilized to enhance your projects, please contact Maziar Mahdavi and Misty Thomison.