Walmart
Project Overview
A failing 50-foot retaining wall at a Walmart distribution center required a rehabilitation solution.
Originally constructed 25 years ago, a Walmart distribution center’s segmental block MSE wall was showing signs of distress. The 50-foot-tall wall retained a 25,000 SF soil embankment supporting a large parking lot, but years of freeze-thaw and a failed drainage layer created a risk of collapse or structural failure. Walmart needed a stabilization solution that would address the conditions while protecting the lot.
Project Objectives
- Uninterrupted warehouse operations throughout construction
- Rehabilitation solution that mitigates safety concerns with embankment collapse
- Finish prior to winter freeze
Location
Johnstown, NY
Market
Capital Improvements
Client
Walmart
Project Size
26,000 SF
Additional Services
The challenges
When considering a removal-and-replacement solution alone, the wall rehabilitation presented the owner with what appeared to be a costly, time-consuming, and nearly unfeasible challenge.
Maintaining building operations
The distribution center adjacent to the wall had to remain operational during construction, so Walmart needed a solution with a short timeline that would not disturb daily operations.
Severe weather
Located in the Adirondack Mountains, the site was subject to freezing temperatures and harsh winter conditions.
Limited access
The wall was positioned behind an active parking lot, with access constrained to a 12 ft wide stone and dirt road separating the wall and a steep decline to the forest.
Excavation hazards
If the wall were to be removed and replaced, the height of the embankment would have required significant soil retention, raising safety concerns.
The solutions
We employed a 2-layer shotcrete and soil nail stabilization system, avoiding complications associated with removal-and-replacement methods. We completed the project 5 months ahead of schedule, avoiding the harshest winter months and saving $200,000 in general condition costs.
Integrated system
An initial shotcrete face was applied before drilling T40/20 hollow bars in an 8’ x 10’ grid. We tension tested the nails to 92,000 lbs, then installed a final shotcrete face over top.
As-shot finish
Since the wall was not public facing, Walmart prioritized speed over aesthetic finish. Providing an as-shot finish contributed to us completing the project early.
Cold weather compliance
By proving concrete temperature behavior, we showed that the shotcrete complied with the provisions of ACI 306-16: cold weather concreting.
Access management
The solution’s small footprint allowed all equipment to fit within the constraints of the access road, minimizing disruption and keeping the facility operations uninterrupted.
