---
title: Case Study - Chemical Grout Box for Interior Elevator Pit Stabilization
description: Stabilized interior elevator pit in sandy soils using ap AP Soil 600 grout box—no shoring, safe ADA retrofit.
---

[Alchatek Infrastructure Repair Blog: Polyurethane Leak Seal Injection, Soil Stabilization, Concrete Leveling ](https://info.alchatek.com/blog)

# [Case Study - Chemical Grout Box for Interior Elevator Pit Stabilization](https://info.alchatek.com/blog/case-study-chemical-grout-box-for-interior-elevator-pit-stabilization)

 Written by [Landon Feese](https://info.alchatek.com/blog/author/landon-feese) | Apr 29, 2026 2:00:02 PM

An interior elevator pit needed for ADA retrofit in a multi‑level building, inside an old stairwell beside a load‑bearing wall on sandy soils. Conventional shoring wasn’t feasible indoors with tight footprint and headroom limits.​ [Stable Soils of Florida](https://www.stablesoils.com/) was called in to assess and remedy the situation.

## Initial Assessment

- Sandy, below‑water‑table soils at a planned 7 ft pit depth.​
- Footing and slab at risk of undermining if excavated untreated.​
- No practical option for sheet piling, slurry wall, or trench box.​

## Proposed Solution

Engineers designed a perimeter grout “box” using AP Soil 600, a low‑viscosity, single‑component permeation resin that bonds wet sands into a rock‑like, load‑bearing mass.

## Procedures

1. Lay out pit and grout‑box perimeter around the planned excavation.​
2. Drill and set probes to depths below the final pit grade.​
3. Inject AP Soil 600 while slowly extracting probes to form overlapping treated columns.​
4. Allow cure, then excavate the pit inside the treated zone.​
5. Grind exposed treated face flat and use it as the outer form for the concrete pit.​

## Results

Stable excavation adjacent to the load‑bearing wall with no observed soil loss.​  
Interior elevator pit completed without conventional shoring or large equipment.​  
Enabled ADA‑compliant vertical access using permeation‑stabilized in‑place soils.

### Want more information on stabilizing soil with polyurethane?

[View full post](https://info.alchatek.com/blog/case-study-chemical-grout-box-for-interior-elevator-pit-stabilization)

```json
{
  "@context" : "http://schema.org",
  "@type" : "BlogPosting",
  "author" : {
    "@type" : "Person",
    "name" : "Landon Feese"
  },
  "dateModified" : "2026-04-29T14:00:02.460Z",
  "datePublished" : "2026-04-29T14:00:02Z",
  "headline" : "Case Study - Chemical Grout Box for Interior Elevator Pit Stabilization",
  "image" : {
    "@type" : "ImageObject",
    "height" : 560,
    "url" : "https://2515821.fs1.hubspotusercontent-na1.net/hubfs/2515821/Social%202%20-%20Chemical%20Grout%20Box%20for%20Interior%20Elevator%20Pit%20Stabilization.jpg",
    "width" : 1080
  },
  "mainEntityOfPage" : "https://info.alchatek.com/blog/case-study-chemical-grout-box-for-interior-elevator-pit-stabilization",
  "publisher" : {
    "@type" : "Organization",
    "logo" : {
      "@type" : "ImageObject",
      "height" : 60,
      "url" : "/hs/hsstatic/content_shared_assets/static-1.4092/img/default-amp-logo.png",
      "width" : 60
    },
    "name" : "Alchatek Blog"
  }
}
```