Foundation Settlement Solution in Cincinnati, Ohio

Problem

In Cincinnati, Ohio, Moxy Hotels purchased a historic building downtown that needed repurposing. However, Moxy was required to preserve and reuse the front face of the building. Due to structural age and limited accessibility, the contractor and engineer decided that a shear wall would be installed in the basement to extend the structure’s full height. This would support the front face during demolition. The foundation soils beneath the new shear wall needed to be strengthened to support the construction loads. The engineer recommended using URETEK.

Analysis

A consulting firm in Cincinnati completed a geotechnical exploration of the problem area. The study encountered voids and weak soils in the fill material just below the proposed location of the shear wall foundation. The largest void found was 2.5”, and the fill soils were composed of loose to medium dense sand, which were not adequate for foundation support. Due to access limitations, there was no way to get any excavation equipment into the building, so hand digging and removal of the slab by hand would have been required without URETEK.

Solution

URETEK Deep Injection® (UDI) was proposed as a quick and effective way to fill and stabilize the underlying soils for the operation. URETEK crews performed the UDI process in a grid pattern across the proposed foundation area. They injected URETEK 486 Star® polymer into the foundation area according to a site-specific injection plan. This both stabilized the weak fill soils and filled all voids to ensure that bearing capacity requirements were met.

Result

URETEK completed the repair in 1 day, and the owner was delighted with the results. This would have been a multiday process with many other challenges like removing, replacing, and compacting fill material and concrete. The UDI process easily provided the required 1500 psf bearing capacity. It also improved constructability by allowing foundation construction to be completed on top of the existing slab. URETEK was able to provide fast, attentive, and efficient work at a fraction of the price.

URETEK Deep Injection® (UDI)

Widely referenced throughout our industry, UDI involves the injection of structural polymer into base and subgrade soils to increase the load bearing capacity. This is achieved by injecting the polymer through small holes drilled directly through the pavement structure to depths determined by site-specific analysis. Our URETEK 486 Star® material flows easily into voids and weak zones within the soil mass below. Through a controlled chemical reaction, the expanding polymer compacts surrounding soils and applies a controlled pressure on targeted areas of the affected pavement above. If needed, a multi-injection design plan is utilized to gently return the pavement to its original grade. The composite material quickly cures into a strong, dimensionally stable, and water-resistant geo-material, providing years of reliable service.

URETEK 486 Star®

URETEK 486 Star® polymer is a two-component, high-density, expanding thermoset polyurethane system. It was developed to be the ideal solution for under-sealing, void filling, lifting of settled pavement, stabilization and stiffening of weak soils, and for encapsulating and sealing buried infrastructure. URETEK 486 Star® is environmentally inert, non-toxic, and resists underground water erosion or weakening due to its industry-leading hydrophobic properties.