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CHAMPAIGN, Illinois – The U.S. Army Engineer Research and Development Center (ERDC) took a significant step in transforming contingency construction. In November 2024, researchers conducted a seismic test on an eco-conscious mass timber shelter that highlights the future of relocatable Cross-Laminated Timber (CLT) structures. This test assessed the performance and safety of the first prototype of a CLT shelter made from thermally modified coastal western hemlock.
The research was conducted in collaboration with the Composite Recycling Technology Center (CRTC) and Washington State University (WSU). Together, these partners are working to revolutionize the construction of sustainable and resilient structures for emergency and temporary housing.
Mass timber technology, which layers wood products through specialized processes, provides a strong and sustainable alternative to traditional materials like steel and concrete. As adoption grows, industry statistics show that as of September 2024, 2,253 multi-family, commercial, or institutional mass timber projects were either in progress or completed in the U.S., according to WoodWorks, a partner on an ERDC Commercial Solutions contract.
The 600-square-foot shelter marks the first assembled model of a CLT B-hut, a shelter designed to house troops in temporary and semi-permanent use cases. The closed shelter, which unfolds from a containerized system, offers modular insulation schemes and enhanced life-cycle environmental performance compared with standard B-huts made from plywood and lumber. Its key advantage lies in its ability to be disassembled and relocated with ease.
“The shelter is designed for both temporary and medium-term use,” said Dr. Pete Stynoski, a research civil engineer at ERDC. “Users can either pre-position the containers ahead of expected events, or quickly transport them to a point of need using standard delivery methods.”
The redeployable shelter was assembled at ERDC’s Construction Engineering Research Laboratory (CERL) within two days. All the necessary components - panels, columns, beams, and connectors -arrived in the form of two shipping containers. To evaluate its structural durability, 80 sensors were placed on the shelter prior to the seismic test.
“The laboratory setting was an excellent space to deploy a full-scale building system,” said Erik Poulin, CRTC materials & process engineer. “Assembly in the testing facility allowed the team to construct the building and test the various deployment systems in a controlled manner, without some of the external variables that could make prototype construction more challenging.”
The testing took place on ERDC-CERL’s state-of-the-art Triaxial Earthquake and Shock Simulator (TESS), a three-dimensional shake table. Simulating seismic and snow load conditions, the team followed the International Code Council's Acceptance Criteria 156. The test pushed the prototype far beyond real-world conditions, providing critical data on its performance under extreme stress.
“This test did a great job of validating the new styles of panel-to-panel and foundation connections that the team designed, making sure that occupants inside would be safe during the extreme event we simulated, which was around three times the accelerations experienced during a typical 50-year event specified in the national design standards,” Stynoski explained.
Jim Wilcoski, research structural engineer and TESS lead at ERDC-CERL, emphasized the unique capabilities of the shake table, saying, "the TESS can test full-scale buildings, revealing failure modes not seen in component tests, where columns, beams, walls, floors, and their connections load one another in unexpected ways. We examine effects from motions in all directions and can apply forces up to 800,000 lbs. vertically and 450,000 lbs. horizontally, making the TESS suitable for testing large structures."
CRTC is a key partner in the project, advancing the use of underutilized tree species like coastal western hemlock to expand the portfolio of U.S.-sourced engineered wood products. This initiative not only increases the availability of such products, but also reduces transportation-related emissions. Beyond military applications, the mass timber shelter has potential for broader use, particularly among tribal communities at risk of experiencing effects of climate change.
“The CRTC team is working with the Makah tribe to source the lumber for these panels. Instead of using what may be considered a low-quality lumber product for concrete formwork or firewood, we can triple its value through the processes of thermal modification and CLT panel production,” Stynoski explained.
“The design lends itself to any situation where quick deployment of a highly durable structure is a necessity,” Poulin added. “The containerized building can be transported via standard freight routes and setup in a matter of days rather than weeks or months for traditional construction. That structure can then be adapted to a permanent installation if needed or packed up and stored for the next deployment scenario.”
As the nation faces increasing challenges from natural disasters, resilient infrastructure is more crucial than ever. This seismic test represents a significant advancement in both material science and engineering, with the potential to transform how shelters and other structures are designed and constructed.
"This test has improved our understanding of component and system-level performance against extreme design cases for snow and seismic loads,” Stynoski said. “We are now armed with real data to prove that, when combined with sound engineering design principles to ensure system-level ductility, the thermal modification process can enable the use of alternative lumber sources for construction.”
Following the success of the seismic test, ERDC and its partners are focused on refining the shelter prototype and deploying the shelter on military installations in the continental U.S. and Alaska. The insights gained will help transition safer, more resilient shelters capable of withstanding extreme weather and seismic events—critical for both military and civilian applications.
| Date Taken: | 01.10.2025 |
| Date Posted: | 01.17.2025 14:43 |
| Story ID: | 489001 |
| Location: | CHAMPAIGN, ILLINOIS, US |
| Web Views: | 9 |
| Downloads: | 0 |
This work, Successful ERDC seismic test advances readiness of mass timber shelter, by Sophia Espinosa, identified by DVIDS, must comply with the restrictions shown on https://www.dvidshub.net/about/copyright.
