Image via Flickr
There are several methods of foundation repair currently on the market. I will provide a brief overview of each.
Drilled & Underreamed Piers
Commonly called Bell-Bottomed Piers, this method has been used on numerous structures and is a standard geotechnically engineered foundation repair method. Most homes costing more than $250,000, multiple story buildings, bridges and petrochemical facilities use this. This method has been thoroughly researched by instrumented load tests to failure by the University of Texas, Texas A&M and numerous other universities. The test by the University of Texas was performed in the Beaumont Clay Formation found in the greater Houston area. This load test data gives engineers the capability of predicting the capacity of a drilled pier with or without an underream (bell) in order to properly design a foundation or its repair.
Perma Pile®
Perma Pile repair methods use cylinders six inches in diameter and one foot long made of concrete which are hydraulically pushed in to the ground.
Cable Lock™
Cable Lock is similar to Perma Pile in that it uses cylinders six inches in diameter by twelve inches long. It differs in that there is a central hole in the cylinder through which a cable is placed.
Ultra-Pile™
Ultra-Pile is similar to both Perma Pile and Cable Lock in its usage of cylinders that are 6×12. It differs in that there is a central hole in the cylinder through which rebar is placed.