#United States #Green Bay #Infrasense #GPR #MSE Walls

Infrasense Employs Ground Penetrating Radar to Assess MSE Wall Structures

In the realm of infrastructure health monitoring, Infrasense, Inc. has taken a significant step forward with their recent project in northeast Wisconsin. The firm was charged with the critical task of evaluating 85 MSE (Mechanically Stabilized Earth) wall structures that play a vital role in supporting vehicular traffic infrastructure, including bridge overpasses and ramp walls. Utilizing cutting-edge ground penetrating radar (GPR) technology, Infrasense aimed to quantify the void space located between the back of facing panels and the wire face of these retaining walls.

Project Overview

The assessment was conducted using a high-resolution handheld GPR system, allowing for an efficient surveying process across various structures. The GPR equipment facilitated the understanding and mapping of void space values, which are essential for determining the structural integrity of the retaining walls. One of the standout aspects of this project was the methodological approach of calibrating GPR results with direct measurements collected via drill holes, ensuring accuracy and reliability in the findings.

Methodology

The project involved nine mobilizations to the site, where data was collected using a sophisticated 2.7 GHz GPR system combined with custom mounting tools. These allowed engineers to scan structures up to 30 feet high from the ground. The data collection process was carefully designed; for long structures, parallel traverses were made approximately two feet apart from the base of the walls up to the coping beam. On structures with unique shapes or narrower profiles, vertical traverses were utilized for effective data acquisition.

Infrasense engineers ensured comprehensive data accuracy by taking direct measurements of void spaces at designated drill locations. For walls exceeding 200 feet in length, multiple sites were assessed, spaced about 200 feet apart to capture variations in void space. To uphold the integrity of the structures post-assessment, epoxy grout filled the drill holes to prevent water infiltration, which could compromise wall strength over time.

Data Analysis

The collected GPR data underwent meticulous analysis to quantify the thickness of void spaces. The results were then exported to a spreadsheet format that facilitated an organized graphical representation. By calculating void thickness values using the known velocity of air against the measured travel times, Infrasense could develop an accurate understanding of the void conditions within each MSE wall. This analytical phase was critical, as it involved fine-tuning calculations based on the milestones established through direct measurements.

The completed spreadsheets provided valuable insights into each structure, detailing maximum and minimum void space values, along with average wall thickness computations. Notably, these metrics enable engineers and infrastructure specialists to determine immediate and long-term maintenance needs or preventative measures to uphold safety standards.

Company Background

Founded in 1987, Infrasense, Inc. has been at the forefront of subsurface scanning technologies, tackling significant challenges in infrastructure assessment. Their commitment to utilizing advanced tools not only supports ongoing evaluations but also contributes significantly to research advancements in nondestructive evaluation techniques. For those looking to explore further, Infrasense's extensive array of services and insights can be found on their website, enabling clients across the nation to enhance their infrastructure maintenance strategies. By marrying technology with engineering expertise, Infrasense continues to ensure critical infrastructure remains safe and operational for future generations.