Investigating the Subsurface Structure of the Chestnut Hill Embankment Dam Using the Ground Penetrating Radar (GPR) Method
Description:
The Chestnut Hill Reservoir earth embankment dam is a component of water storage and flood prevention infrastructure for the city of Boston, MA. To study its internal structure, a Ground Penetrating Radar (GPR) survey was conducted to image and analyze the subsurface composition of the dam. Using the GSSI SIR 3000 GPR system, survey lines were taken along the embankment at 35-meter intervals, focusing on the two block houses located along the dam. The survey revealed strong horizontal reflections near a structure on the dam called the First Block House (FBH) at approximately 170 meters from the survey's starting point. These reflections indicate the presence of concrete slabs, and other underground structures that contained water pumping equipment. Multiple hyperbolas in the radargrams near the FBH suggest the presence of underground metallic pipes, which are essential for water passage and positioned very close to the surface. Similar features were observed near a Second Block House (SBH) at 625–680 meters from the survey start, with diffractions extending from 0.5 to 1.5 meters depth, confirming the presence of utilities. Additional findings include nearly horizontal layers of material overlaying the embankment, likely corresponding to gravel paths used as reinforcement. A drainage pipe was identified at approximately 285 meters from the survey's start, validated through ground truthing and imagery. Transitions between lithologies were observed at about 430 meters, marked by distinct changes in radar reflections, suggesting variations in the dam's construction materials. This study highlights the effectiveness of GPR in producing high-resolution images of the interior composition of earth embankment dams.
Session: New Directions in Environmental, Seismic Hazard and Mineral Resource Exploration Studies [Poster]
Type: Poster
Date: 4/17/2025
Presentation Time: 08:00 AM (local time)
Presenting Author: Victor
Student Presenter: Yes
Invited Presentation:
Poster Number: 116
Authors
Victor Olawoyin Presenting Author olawoyiv@bc.edu Boston College |
John Ebel Corresponding Author john.ebel@bc.edu Boston College |
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Investigating the Subsurface Structure of the Chestnut Hill Embankment Dam Using the Ground Penetrating Radar (GPR) Method
Category
New Directions in Environmental, Seismic Hazard and Mineral Resource Exploration Studies