How The Dwyer Company Supported a Building Addition Over an Existing Storm Line at Yorktown High School
- Project Type: Commercial
- Project Services: Deep Foundation Systems, Micropiles
Yorktown High School built an addition in Yorktown, Indiana with an existing storm line running through the middle of the new footprint. The Dwyer Company installed 13 micropiles to support the columns near that line, working with general contractor Fredericks, Inc and engineer Civil Solutions. Each pile supports loads between 15 and 42 kips, and the foundations extend past the storm line elevation so the addition puts no surcharge on the pipe. The structural drawings specified helical piers, and the soils the crew encountered led Dwyer to install micropiles instead.
Building over a utility line that cannot be moved?
Quick Facts
- Yorktown, Indiana
- Project Type: Commercial – New Construction
- Owner: Yorktown High School
- Foundation System: Micropiles, 13 installed for the building addition
- Pile Capacity: 15 to 42 kips
- Design Change: Structural drawings specified helical piers; micropiles installed in their place based on the soils encountered
- Site Conditions: Existing storm line running through the middle of the addition footprint
- Partners: Fredericks, Inc (general contractor), Civil Solutions (engineer)
The Challenge
An existing storm line ran straight through the middle of the new addition. Columns landed near it, and shallow footings at those locations would have put surcharge on the line, loading a pipe that was never sized to carry a building. The foundations had to reach below the storm line elevation so the load passed it by.
Working that close to a buried utility also set the pace. Each pile location near the line called for observation and care to keep the crew off the pipe. Soil conditions added the other wrinkle. The structural drawings specified helical piers, and what the crew found in the ground called for a different system.
Key Project Details
micropiles installed for the building addition
Micropiles installed in lieu of the helical piers shown on the structural drawings
The Solution: Micropile Foundation System
The Dwyer Company installed 13 micropiles to carry the columns near the storm line. Each pile supports between 15 and 42 kips and takes its load below the elevation of the line, so the pipe carries nothing from the addition above it.
Soil conditions on site ruled out the helical pier design the structural drawings called for, so Dwyer proposed micropiles and installed them in their place. Drilled and grouted piles handled the material the crew found. Coordination with Fredericks, Inc and Civil Solutions kept the design change moving, and close observation at every location near the line kept the utility intact.
The Impact
Storm line kept free of surcharge
The foundations bear below the line elevation, so the addition puts no load on the pipe.
Capacity where the columns land
Each pile supports between 15 and 42 kips, matched to the column it carries.
System matched to the soils
Dwyer replaced the specified helical piers with micropiles once the ground showed what it would take.
Utility protected through installation
Observation at each pile location near the line kept the crew clear of the existing pipe.
Why Micropiles?
Micropiles let The Dwyer Company carry the addition past a storm line in soils that ruled out the helical pier design on the drawings.
- Drilled through difficult soils – Grouted construction advances in material that resists driven and turned systems.
- High capacity, small diameter – Piles carry substantial load through a footprint that fits between existing utilities.
- Depth past buried lines – Load transfers below the elevation of a utility, so nothing bears on the pipe.
- Precise placement – Compact equipment sets piles where the columns need them, including close to a line that has to stay put.
Why Choose The Dwyer Company for structural integrity?
Deep History • Solid Choice
The Dwyer Company’s proven track record in commercial and industrial foundation systems made us the trusted partner for the Yorktown High School addition. Working alongside Fredericks, Inc and Civil Solutions, our crew adapted the foundation design to the soils on site and installed 13 micropiles that carry the addition past the existing storm line.
Have a utility line sitting in the middle of your building footprint?