Why does the steel pier go deeper?
The steel pier will penetrate deeper because the first section of pier pipe has a side friction reducer, which makes the hole wider than the pier pipe that follows it down. The steel pier pipe is also of a smaller diameter than the pressed concrete pier blocks. The pressed concrete pier has no side friction reducer and will develop the maximum driving pressure at considerably less depth than the steel pier. The only force available to press either pier is the weight of the building. When it begins to lift, that is the maximum depth for that pier. A point or cone on the first section of the pressed concrete pier won’t do much to increase the depth. Most of the resistance comes from the side friction against the soil. All concrete piers achieve most of their load capacity through this side friction. This is why, in engineering terms, the concrete pier is referred to as a friction pier. One more major point to consider is that if a steel pier is not driven to rock, it will not be possible
