Thursday, July 17, 2025

GFRP Reinforced Bridge Barriers: Experiment Testing

The reported work includes the experiment testing of glass fiber reinforced polymer (GFRP) and steel reinforced concrete bridge barriers. A total of four reinforced concrete barriers were prepared, including three GFRP reinforced barriers and one mild steel reinforced barrier, and cast on two concrete slabs. Impact testing was conducted using a cart with weight and a long straight sled system. The force, displacement, and strain data were measured. The results demonstrated that GFRP is fully capable of withstanding impact loads that could occur in real-world scenarios.


Report number: cmr 25-010
Published: July 2025
Project number: TR202319
Authors: Congjie Wie, Manish Kumar Gadhe, John J. Myers, and Chenglin Wu
Performing organization: Missouri University of Science & Technology

Wednesday, July 2, 2025

Shear Wave Velocity Measurements

The Missouri Department of Transportation (MoDOT) commissioned SCI Engineering, Inc. to investigate cost-effective, non-intrusive geophysical methods for determining time-averaged shear wave velocity (Vs) profiles to a depth of 100 feet, based on anticipated updates to AASHTO seismic site classification specifications. Following a comprehensive literature review, eight candidate methods were identified. Of these, four methods—Active Multichannel Analysis of Surface Waves (Active MASW), Passive Multichannel Analysis of Surface Waves (Passive MASW), Active Refraction Microtremor (Active ReMi), and Passive Refraction Microtremor (Passive ReMi)—were selected for field testing based on their practicality and effectiveness.

Field evaluations were conducted at three sites: the SCI Office in O’Fallon, Illinois; the I-270 Chain of Rocks Bridge; and the MLK Connector in Illinois. The sites were selected based on access, availability of existing groundtruth subsurface soil information, as well as representing a variety of subsurface profiles.  Various geophone spacings and array configurations were tested. Performance metrics included depth of investigation, ease of deployment, data quality, and interpretability. Results demonstrated that combining Active and Passive MASW methods offered the most reliable and practical solution, providing consistent results, minimal operational complexity, and shared equipment and software requirements.

SCI Engineering developed a comprehensive User Manual and conducted field demonstrations to train MoDOT personnel in the acquisition, processing, and interpretation of MASW data. Adoption of these methods will streamline MoDOT’s seismic site classification processes, align practices with forthcoming AASHTO requirements, and enhance MoDOT’s internal technical capacity.


Report number: cmr 25-009
Published: June 2025
Project number: TR202403
Authors: Evgeniy "Eugene" Torgashov, Neil Anderson, and Thomas J. Casey
Performing organization: SCI Engineering, Inc.