pullout capacity of grouted pier/pile in rock

[gn214]

How would you estimate the pullout capacity of a grouted pier or pile in drilled rock?

Thanks.

 

[GeoPaveTraffic]

First figure the skin friction capacity of the pile just like you would for a downward load. Then you need to look at the joint pattern of the rock versus the depth of embedment of the pile into the rock to determine if the rock will tend to break/separate on joint planes that are smaller than a typical pullout cone. Then look at the weight of the smallest pratical pullout cone versus the uplift (pullout) capacity that has been calculated.