Abstract: A pier assembly for supporting a structure has a vertically oriented central axis and includes a plurality of horizontally spaced apart elongate members disposed in the ground and arranged about the central axis. Each elongate members directly contacts the ground. Each elongate member has a length-to-width ratio greater than 10.0.

Abstract: A pier assembly for supporting a structure includes a guide member having a base plate and a plurality of tubular guides extending from the base plate. In addition, the base plate includes a plurality of through holes and each tubular guide includes a through passage aligned with one of the through holes of the base plate. Further, the pier assembly includes a plurality of elongate members. Each elongate member extends through one through hole in the base plate and the through passage of the corresponding tubular guide.

Abstract: A pile segment for foundation underpinning. In some embodiments, the pile segment includes a head, a trunk extending from the head, and a throughbore passing axially through the head and the trunk. The throughbore has a longitudinal centerline. The area of a cross-section through the head and normal to the centerline is greater than the area of a cross-section through the trunk and normal to the centerline.

Abstract: A foundation underpinning is disclosed. In some embodiments, the foundation underpinning includes a pile having one or more pile segments and an elongated reinforcing tubular member. Each of the one or more pile segments includes a throughbore passing axially through the head and the trunk. The throughbores of the one or more pile segments are vertically aligned forming a passage through the pile, and the elongated reinforcing tubular is disposed within the passage.

Abstract: A jetting system for installing foundation underpinning is disclosed. In some embodiments, the jetting system includes a pile having one or more pile segments, an elongated reinforcing tubular member, and a jetting tube. Each of the one or more pile segments includes a throughbore passing axially through the head and the trunk. The throughbores of the one or more pile segments are vertically aligned forming a passage through the pile. The elongated reinforcing tubular is disposed within the passage, and the jetting tube is inserted into the reinforcing tubular.