Underpinning existing foundation

[bruinboy]

We've got an existing residence (one-story) with a pier and grade beam foundation. The existing piers are shallow. The house was built on fill and is sliding a bit so we are going to use drilled piers adjacent to the exterior grade beams that will extend down into bedrock. I'm looking for advice on how to connect the new piers to the grade beams. As I have it now, each pier will have a haunch (designed like a corbel) that the existing grade beam will rest on. The upper corner of the haunch will have a steel angle with 3 threaded rods per haunch epoxied up into the existing grade beam and left to extend into the new haunch. Is this the best way to make this connection or can anyone provide me with alternate suggestions?

 

[DaveAtkins]

There are companies which specialize in underpinning grade beams. They have proprietary devices which support the underside of a grade beam similar to the way you have described, while extending down to firm soil (their piles are not concrete). This may be cheaper than what you are proposing.

DaveAtkins

 

[jheidt2543]

Check with A. B. Chance Co. which makes helical, drill-in anchors and brackets for attachment to the existing foundation. DaveAtkins is right, it should be much cheaper and quicker.