An aging prison building in Fort Worth, Texas had seen areas of settlement as much as 7.5 inches inside the building. URETEK successfully implemented their URETEK Method to lift the sunken slabs and stabilize the floor of the Prison’s Rec Hall. Check out the video below or visit URETEK’s blog post for more info. [Source: URETEK ICR YouTube Channel. Image: YouTube]
Univ. of Missouri’s Historic Memorial Union, Built to Honor WWI Dead, Gets New Life with TerraThane Geotechnical Foam
MOUNT AIRY, NC—The Univ. of Missouri’s iconic Memorial Union, with its Gothic architecture and central bell tower, was built to commemorate the 117 Mizzou alumni who lost their lives in WWI, and has been under silent attack. Like all buildings built atop the ancient dry riverbeds of the tributary valleys of the Missouri River, the soil beneath is a mixture of sand, clay, and fine rock particles and highly susceptible to erosion from water. So, while hundreds of thousands of students walked the hallways of the building, water escaping steam pipes far beneath caused severe drying of the soil and destabilized it enough so that erosion created voids, or cavities in the soil, some as large as four feet. In turn, this caused the concrete slab floors atop the voids to become uneven, and the eventual danger of even greater problems loomed large.
A team of engineers went after the problem, including MU alums, Matt VanderTuig, P.E., of Bartlett & West, Jefferson City, MO, and Mark Whitehead, P.E. with extensive structural design and environmental engineering management experience. They suggested to Chris Hentges, president of SIRCAL Contracting, Jefferson City, the general contractor in charge of the job, that instead of using the older method of mudjacking, a highly involved and intrusive process of drilling large holes in the slabs—sometimes removing the slabs entirely—and pumping “mud”, ultra-heavy Portland cement-based grout, into the void, then leveling the slabs, that the university might better be served by using the newer polyurethane foam system method called “foamjacking” or “polyjacking.”
[Editor] Be sure to click through for the rest of the interesting project from GeoPrac sponsor NCFI Polyurethanes and TerraThane! [/Editor]
The American Society for Testing and Materials, or ASTM, No. 57 stone is often used as sub base fill material below road surfaces and buildings. It is a fragmented stone with angular edges and is regularly utilized as a drainage layer when used with geotextile fabric. Although the material is touted by many as "self-compacting," excess voids left from zero compactive effort in locations with little confinement may not eliminate the possibility of future settlement. What happens when the environment above the No. 57 stone causes it to settle?
[Editor] Read on for the answer to this interesting question in the case of settlement of a structure at the University of North Carolina at Chapel Hill. The contributed article by Katherine Witt describes how URETEK Mid-Atlantic used their high-density polyurethane resin to stabilize the No. 57 stone beneath a settled foundation as well as lift the surrounding slab back into place. [/Editor]