Solving problems with soil nails in IA, KS, MO and NE
Experienced foundation repair specialists and geotechnical engineers appreciate soil nails for their ability to solve soil stabilization problems in cost-effective ways. For example, when a basement foundation must be excavated right next to an existing building with a slab foundation, it’s critical to prevent the soil next to the slab from caving into the excavation.
Soil nails, used in combination with shotcrete, enable the contractor to quickly and inexpensively construct a retaining wall that stabilizes the excavation while the new basement foundation is under construction.
It’s also possible to construct permanent retaining walls with soil nails and shotcrete. This technique is faster, easier, less expensive and less disruptive than building the same wall with poured concrete or concrete masonry units (CMUs).
A soil nail retaining wall can be built from the top down, in increments of 6ft. or so (See “Building a soil nail and shotcrete retaining wall” below). But a poured concrete or CMU retaining wall must be built from the bottom up. This necessitates a complete, full-depth excavation at the start of the project, a scope of work that may be too major and too disruptive in some locations. Soil nailing has become popular because it eliminates or minimizes these impacts.
Like a conventional concrete retaining wall, a retaining wall that utilizes soil nails is an engineering exercise involving soil analysis, loading calculations and other important design factors. Once the work begins, there are three basic steps:
When these three steps are completed, a second excavation is made and the same three steps are repeated. This 3-step construction cycle continues until the wall reaches its final design height.
Used in combination, soil nails and shotcrete give foundation repair contractors a number of problem-solving options that are useful to residential and commercial customers alike. Being able to build retaining walls quickly and inexpensively makes it possible to create workable level areas on sloping sites that would otherwise be unusable. Soil nail and shotcrete techniques can also stabilize slopes and create temporary walls so that more permanent structural work can take place safely.