A look at foundation drilling projects around the world.

Road Interchange Project

A major road interchange project in Hong Kong involved extensive foundation drilling on a steep hillside that consist of Grade III & Grade IV granite with a limestone/marble section. Because of the difficult conditions, careful planning was required in order to allow four drill rigs to be erected and between foundation holes without interfering with other work being conducted in the confined area.

The project involved the construction of new interchange ramps along the hillside. Goodwill Construction & Engineering Ltd. drilled 24-inch foundation holes for H-beams that will be concreted in place. Drilling with Numa Champion 180 down hole hammers and bits, approximately 300 H-beam piles were installed to depths between 30 feet and 130 feet.

In most instances, single-level pile caps typically are square, and are supported by four vertical piles. Due to the steep terrain and to accommodate the sloping ramps, two-level and three-level pile caps, with as many as 16 piles per group – vertical and raking – were required.

Caissons for Elevator

North Carolina A&T State University’s Morrison Hall is a 121-bed residential facility. It is on the National Historic Register and required an extensive renovation to meet current fire codes and ADA requirements. The project included the installation of a new elevator addition, for which caissons were drilled.

CFA Piles Constructed

Continuous flight auger (CFA) piles are constructed by utilizing specialized drilling equipment and methods developed, in part, by Pomonoa, Calif.-based D. J. Scheffler Inc. The CFA pile is constructed by drilling a hollow-stem auger into the ground. The auger is drilled to the pile’s designed depth in a single operation. Thus, very little soil is displaced. Once at depth, concrete is pumped through the auger’s stem, and fills the hole as the auger is extracted. After the concrete is placed, the steel reinforcement, either an I-beam or a re-bar cage, is placed into the still-wet concrete column. Advanced computer instrumentation monitors all aspects of pile placement including: depth, speed of auger rotation and rate of advancement, torque, concrete head pressure, and volume of concrete placed. CFA piles can be constructed in diameters ranging from 16 inches to 48 inches, and up to 120 feet deep.

Bridge Project in S.C.

Belton, S.C.-based Lee & Sims Drilling Services Inc. handles the foundation drilling for the Adam Miller Road Bridge over Gilder Creek in Greenville County, S.C. The project involved one 78-inch diameter drilled shaft with a 72-inch diameter rock socket, to a depth of 25 feet, and 10 30-inch diameter drilled piles to a maximum depth of 25 feet.

A Landmark Foundation

Drilling 40-foot-deep caissons and installing foundation steel for the Landmark condominium community in Scottsdale, Ariz. Butte Landmark LLC is the developer.