Performance of Helical Piles with Grouted Shafts

Abstract

A new foundation system employing in situ grouting of helical screw piles has recently been developed. As the anchor is installed into the soil, a column of grout is "pulled down" around the anchor shaft providing an in-situ grouted shaft. This foundation system has been successfully employed at several sites with very soft soils overlying a more competent stratum. The grouted column significantly increases the anchor shaft's resistance to buckling and provides additional corrosion protection. The grouted shaft also increases the stiffness of the column and bearing capacity of the foundation. The paper discusses design considerations, installation procedures and results of full scale field load tests. Several case histories with field performance data are also described.