The new Bozeman Public Safety Center has been constructed at the site of the former MDT yard facility, located on the southwest corner of N. Rouse Avenue and W. Oak Street on the northeast side of Bozeman. This 8-acre site development includes a large, multi-story building and several asphalt parking lots and roadways. The building houses the police department, the municipal court facilities, and one of the City’s fire stations.

AESI first became involved with the project in 2014 during the initial concept phase. At that time, we were retained for a preliminary geotechnical investigation and report of the subject property. In 2019, as the project design progressed, we performed additional field explorations to better characterize the site conditions. This was followed by the preparation of the final geotechnical report for design and construction.

The two biggest findings of the geotechnical work were that the site was blanketed by a 1.5 to 2.0-foot layer of asphalt millings/roadmix gravel and that the “target” bearing material for the building was the native sandy gravel at a depth of generally 5.0 to 7.0 feet. To save a substantial amount of money, we recommended stripping/salvaging all of the existing asphalt-laden gravel materials from the surface of the site and re-using these materials as part of the sub-base gravel section under new asphalt areas. This saved on both the haul-off of the material and the importing of all new gravel. Due to the footprint size of the building and the number of interior footings, we recognized that traditional footing over-excavation/replacement down to the “target” native gravel would be impractical and uneconomical. Instead of standard foundation earthwork, we recommended a ground improvement system consisting of rammed aggregate piers under all foundation elements (including perimeter, interior, and exterior footings). This foundation system was chosen and designed to include over 650, 30-inch piers that extended down into the “target” native gravel.

AESI has been involved with the site and foundation construction since it began in the spring of 2020. We observed the stripping/salvaging of the asphalt-laden gravel materials, the preparation of subgrade, and the placement of the sub-base gravel sections under new asphalt areas. In the building area, we monitored the construction of the gravel building pad, provided QA inspection/oversight during the installation of the rammed aggregate piers, and observed the foundation excavation and the exposed tops of the piers under footing locations.

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Site Conditions: The site was covered by a 1.5 to 2.0-foot layer of asphalt millings/roadmix gravel, which required careful management to reuse these materials effectively and economically.

Foundation Design: The native sandy gravel, identified as the “target” bearing material, was located at a depth of 5.0 to 7.0 feet. Traditional footing over-excavation and replacement were impractical and uneconomical due to the building’s footprint and the number of interior footings.

Ground Improvement: Implementing a ground improvement system with over 650 rammed aggregate piers was a significant undertaking. This required precise installation and quality assurance to ensure the stability and integrity of the foundation.

Material Management: Stripping and salvaging the existing asphalt-laden gravel materials and reusing them as part of the sub-base gravel section under new asphalt areas required meticulous planning and execution to save costs and reduce waste.

Coordination and Oversight: Continuous involvement from AESI for site and foundation construction, including monitoring subgrade preparation, gravel building pad construction, and the installation of rammed aggregate piers, was essential to address any issues promptly and maintain project timelines.

Reuse of Existing Materials: Stripped and salvaged the existing asphalt-laden gravel materials from the site and reused them as part of the sub-base gravel section under new asphalt areas. This approach saved on both the cost of hauling off the material and the expense of importing new gravel, making the project more economical.

Ground Improvement System: Instead of traditional footing over-excavation, a ground improvement system using rammed aggregate piers was implemented under all foundation elements. This method provided a stable foundation for the building, with over 650, 30-inch piers extending into the native sandy gravel, ensuring the structural integrity of the building.

Cost Savings: The reuse of existing materials and the innovative foundation solution significantly reduced project costs.

Structural Integrity: The ground improvement system ensured a stable and durable foundation, capable of supporting the large, multi-story building.

Efficient Project Execution: Continuous monitoring and quality assurance helped maintain project timelines and addressed any issues promptly, leading to a smooth construction process.

The subject property, encompassing approximately 24 acres, was developed into a five-lot mixed-use subdivision. The project design incorporated an existing single-family home while optimizing the layout for both commercial and residential use. The eastern portion of the site features three commercial lots, while the western portion includes two residential lots. Zoning regulations designate a 200-foot corridor along Highway 191 as commercial, with the remainder classified for mixed use in accordance with the Four Corners Neighborhood Zoning Jurisdiction. This zoning framework supports the intended development, ensuring compatibility with surrounding land uses.

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This project required careful coordination with the Montana Department of Transportation (MDT) to secure approach permits and establish shared access easements and agreements. Additionally, improvements to the existing water conveyance facility involved extensive collaboration with local agencies and stakeholders. Utility service planning posed another challenge, as the project site was not directly adjacent to existing infrastructure, necessitating strategic design solutions. The development also required comprehensive water and wastewater system design to meet regulatory standards while supporting both residential and commercial uses.

To overcome the project’s challenges, our team implemented strategic solutions tailored to site constraints and regulatory requirements. We collaborated with the Montana Department of Transportation (MDT) and neighboring property owners to establish shared public access and optimal approach locations, ensuring efficient traffic flow and accessibility. Coordination with ditch users and headgate operators facilitated improvements to hydraulic structures crossing the water conveyance facility, enhancing water management and functionality.

Addressing the lack of adjacent utility infrastructure, we worked closely with utility providers to plan and secure necessary services, obtaining easements and alignments to extend utilities from off-site locations to meet the subdivision’s commercial and residential demands. For wastewater management, we designed a public wastewater system along with multiple on-site wastewater treatment and disposal systems, incorporating Level 2 treatment capabilities to ensure compliance with environmental standards and long-term sustainability. Through these efforts, the project successfully delivered a well-planned, functional, and compliant mixed-use development.

AESI, in collaboration with Western EcoSystems Technology, conducted wetland delineations and rare plant surveys across six sites in Yellowstone National Park for the National Park Service. Spanning approximately 230 acres, these surveys aimed to identify sensitive environmental areas to guide heavy equipment placement for future fuel treatment projects. AESI utilized sub-meter GPS technology to record wetland boundaries, captured site photographs, and integrated data onto geo-referenced aerial imagery and U.S. Geological Survey maps. Additionally, field teams mapped ordinary high water marks for stream channels and water bodies within the project areas. The final reports provided detailed classifications of palustrine emergent and palustrine forested wetlands, including key vegetation and hydrology characteristics essential for boundary determinations.

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The project faced a tight timeline, as the contract was awarded in mid-August, leaving limited time to plan and complete the field surveys within the short growing season. This constraint required rapid mobilization and efficient execution to ensure accurate data collection before seasonal changes impacted plant identification and wetland assessments.

AESI quickly developed a comprehensive field survey plan, streamlining methods, sampling protocols, and safety measures to maximize efficiency. Field teams worked within the constrained timeframe to collect high-quality data, ensuring thorough documentation of wetland boundaries and rare plant locations. The final reports provided the National Park Service with precise maps and detailed environmental assessments, supporting informed decision-making for future land management and conservation efforts.

In the summer of 2024, AESI provided comprehensive geotechnical engineering and survey services for a new 4,250-square-foot residence in Bridger Canyon, Montana. The project site, a 20-acre property with a moderately steep southeast-facing slope, required detailed analysis and innovative solutions to ensure stability and functionality. Our team conducted extensive site investigations, including test pit explorations and laboratory testing, to assess subsurface conditions. We identified clayey residual soils and recommended over-excavation to stable weathered siltstone/sandstone, supported by 12 inches of structural fill. Additionally, we designed and monitored the installation of boulder walls up to 12 feet high to retain driveway cuts, ensuring both slope stability and aesthetic appeal.

We also completed a comprehensive slope stability analysis, confirming the site’s stability under typical foundation loading and moderate seismic events. We provided foundation support recommendations, allowable bearing criteria, and anticipated settlements to ensure a robust and durable foundation.

The success of this project depended on utilizing drone survey data and soil logs to create detailed AutoCAD Civil 3D soil horizon models. We also assisted with the layout of proposed horizontal drains and the design of access roads, improving site accessibility and drainage. Notably, we employed MASW (Multi-channel Analysis of Surface Waves), a geophysical analysis, to provide a site-specific seismic classification, ensuring the residence’s resilience against seismic activity.

Our integrated approach and expert solutions ensured the successful planning, design, and construction of this beautiful residence.

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Subsurface Conditions: The presence of clayey upper residual soils required careful management. These soils needed to be over-excavated to reach stable weathered siltstone/sandstone, which added complexity to the foundation preparation.

Slope Stability: Ensuring the stability of the moderately steep southeast-facing slope was crucial. This involved conducting a comprehensive slope stability analysis and designing appropriate measures, such as boulder walls, to retain driveway cuts and prevent erosion.

Seismic Considerations: The project required a site-specific seismic classification to ensure the residence’s resilience against seismic activity. This was addressed using a MASW (Multi-channel Analysis of Surface Waves) geophysical analysis, which provided detailed insights into the site’s seismic characteristics.

Integration of Data: Creating accurate soil horizon models and stability models required integrating various data sources, including drone surveys and borehole logs. This necessitated advanced software tools like AutoCAD Civil 3D and SLOPE/W to develop detailed and reliable models.

Foundation Design: Over-excavated the clayey upper residual soils to reach stable weathered siltstone/sandstone and used 12 inches of structural fill for foundation support. This provided a solid and stable foundation, ensuring the long-term durability of the residence.

Slope Stability Measures: Conducted a comprehensive slope stability analysis and designed boulder walls up to 12 feet high to retain driveway cuts. These measures effectively stabilized the moderately steep slope, preventing erosion and ensuring the safety of the structure.

Seismic Resilience: Employed MASW (Multi-channel Analysis of Surface Waves) geophysical analysis to provide a site-specific seismic classification. This ensured the residence was designed to withstand seismic activity, enhancing its resilience and safety.

Integrated Data Modeling: Utilized drone survey data and soil logs to create detailed AutoCAD Civil 3D soil horizon models and SLOPE/W stability models. These models provided a comprehensive understanding of the site conditions, informing better design and construction decisions.