There is more than one way to repair foundation.
Helical piers have been in use for the stabilization of foundations since the early 1800's. Current uses for helical piers include underpinning foundations for commercial and residential structures, foundation repair, light poles, retaining walls tie-back anchors, pipeline and pumping equipment supports, elevated walkways, bridge abutments, and other numerous uses in the electric utility industry. Many times helical anchors are the solution for your foundation repair project due to ease of installation, minimal vibration, immediate load transfer, each of load capacity testing, installation not affected by weather, little to no disturbance to construction sited, to name a few.
Steel piers are an excellent choice for most foundation repair issues which are caused by organic soils, swelling clays, poor compaction, improper footing embedment, and erosion or run off. Steel piers, also known as push piers, mini-piles or resistance piers are an economical and permanent solution for your home that has settled. Steel piers are an end bearing pier that does not rely on the soils skin friction to provide support. These underpinning piers are able to develop a factor of safety due to the fact that they are individually load tested during installation.
Polyurethane Foam Stabilization & Lifting:
Polyurethane is one of many chemical grout injection solutions provided by Foundation Professionals. For instance, concrete slabs that are settling or rocking can be stabilized by injecting structural polyurethane foam into the voids beneath the slabs. Slabs can also be lifted back to their original position using the Proprietary Precision Lift process.
Slab stabilization is accomplished by injecting structural foam such as Precision Lift 3.5# and Precision Lift 4.75# products manufactured by Prime Resins. The injected mixture flows into the voids and fills the cavities by expanding up to 20 times (depending on formulation). The foam will fully expand and will be traffic ready within 15 minutes (85% strength) of application. Often, it is necessary to lift a concrete highway, warehouse floor slab, or even a building due to settlement. This can be accomplished with a two step process.
First voids are filled and loosely compacted soil is consolidated. This can be accomplished by either compaction grouting or permeation grouting. Compaction grouting is a process by which rapidly expanding polyurethane foam (fully expanded in 30 seconds) is injected into the ground. The foam fills voids in the immediate area and compacts the surrounding soil using expansive pressure. However, permeation grouting is a process by which a much slower reacting foam is injected into the soil to permeate the soil matrix prior to expanding. The expansion is limited due to the low levels of catalyst. Once cure, the Prime Fixed "glues: the soil particles together. Prim Flex 910 and 920 are the ideal product for permeation grouting.
Second, and after consolidating the subgrade, it is time for the Precision Lift process. For this process, a rapidly expanding foam is injected directly beneath the slab in short bursts. By speeding up the reaction with heat and by controlling the amount of material injected beneath the slab, we are able to control how much the slab is lifted.
Cement Grout Injection Solution:
When there is a sinking foundation, a throughout evaluation of the subsurface needs to be performed before proceeding. This evaluation will provide information necessary to determine which repair procedure to apply. Under many circumstances, foundation related work does not require the physical properties exhibited by epoxy grouting materials. When this occurs, a high performance, non-shrinking cement grout should be used to achieve desired results.
Cement Grouting is the injection of a sand-cement mixture into the ground to improve it's strength or to reduce its permeability. It can also be used to coagulate granular soils in order to underpin foundations or provide excavation support.
Another benefit of this procedure is it's compliance to various surrounding environments. Due to the relatively small injection pressure ports, it can be performed with minimal disruption to building-use. Since the effectiveness of cement grouting is independent of the structural connections, the technique is readily adaptable to existing foundations.
This type of grout uses controlled displacement to increase the density of soft or loose soils. Sinkhole remediation, structural stabilization, and settlement control are a few examples of what compaction grouting can be used for.
While cement grouting the injections fill voids at strategic locations under balanced pressure; in compaction grouting, a stuff mortar-like grout is injected at high pressure to displace and compact the surrounding soils. As they form, they intensely compact the soil around them. Compaction piles can be formed in the same manner to create a continuous structural support for foundations.
Information provided by Foundation Professionals of Florida