Is My Foundation Failing?
Structure foundations serve the purpose of slowing the effect of gravity and other forces on a structure built on soils. Over time, foundations can become out of level through soil settlement and/or heave. Foundations are engineered to move uniformly as a unit, not differently (differential movement). Differential movement is the #1 cause of “Foundation Failure”. There can be several causes for this movement, and sometimes the symptoms can be misleading. The best way to ascertain whether or not you have a problem is to give us a call (775-284-1964). We will inspect your property for FREE, determine the severity and possible remediation. There is no “one size fits all” solution to foundation repair, and if you don’t need a repair, we will tell you.
How Do We Fix It?
The most common foundation repair is “underpinning”. Deep foundation systems such as helical piles or micropiles are installed along the area of foundation to be repaired. After the installation is complete, the piles are connected to your existing foundation using engineered steel brackets. The load of the structure is then transferred from the soil to the piles using a hydraulic lifting and leveling system. During the loading process, the foundation can be raised or lowered depending on the need of the structure to return to level. There are many foundation types, and some require a different approach for repair, but there are solutions to all foundation problems. We have the knowledge and expertise to determine the best repair option available for your particular foundation.
How Much Does It Cost?
We wish it was that simple! There are many factors to consider in engineering a foundation repair, including but not limited to, underpinning pile type and method, depth of pile installations, pile spacing, equipment access to name a few. Therefore it is difficult to provide an accurate cost proposal without a thorough investigation. Some of the factors that must be considered include:
- Foundation & Structure Construction (Type)
- Structure Loads – Dead plus Live Loads (Wind, Snow, Etc.)
- Soil Type(s) & Characteristics at Depth (When Available)
- Possible Failure Causes
- Repair Options Due to Soil Conditions
- Repair & Equipment Access
- Structure Floor Elevations
- Landscaping proximity and damage potential
- Previous Repairs
We recommend contacting us (775.284.1964) to schedule a FREE site inspection with one of our experts. Once an on-site inspection and evaluation has been completed, we can develop a preliminary plan of repair including a cost estimate. One of our experts will explain the proposed repair and answer any questions.
What are Helical Piles?
Helical piles install into soils much the same way screws install into wood. The purpose of any pile is to transfer structure loads to a depth below grade where soil moisture content is stable and the soil strata is suitable for load bearing. Helical piles are unique because of their installation method. As the piles are installed, the torque required for advancement is monitored and recorded. Decades of empirical testing has documented that there is a correlation between the installation torque and the piles’ capacity. Once the structure’s loads have been determined, we can mathematically determine the minimum installation torque energy required to achieve pile capacities to support the structure including a factor of safety. In some cases, usually larger commercial projects, the design engineer may require physical load testing of a percentage of the piles to be installed. VersaGrade owns pile test frames, hydraulic testing equipment and measuring instrumentation to perform both compression and tension testing. Helical piles can be used in tension or compression, and are used for approximately 75% of foundation repairs.
What are MicroPiles / Soil Nails?
Micropiles and soil nails are essentially the same thing; the difference is in their application. Micropiles are used in tension and compression as load bearing tendons. Soil nails are typically used in steep slope or wall stabilization where the nails are installed beyond the soils’ failure plane (angle of internal friction). Both applications utilize a hollow bar steel tendon with a sacrificial cutting bit that is installed with a rotary-percussion hammer. During installation, a neat cement and water mixture is pressure injected down the hollow bar and through the cutting bit into the soils surrounding the hollow bar/tendon. This method of installation is called Injection BOring (IBO). IBO piles and soil nails develop their strength, in both compression and tension, by the summation of the steel tendon plus the strength of the annular soil-cement bond with its surrounding soils, referred to as the area of influence.
The area of influence is the annular area in which the soils are cemented together. Micropiles and soil nails can be installed in almost any soil condition with excellent load bearing characteristics which makes them an ideal alternative in rocky or high blow count (high density) soils where helical pile installations are not conducive.