36-Inch Caissons on a 70% Hillside Slope

The Stonehill Lane project in Brentwood presented two major challenges from the beginning: extremely limited access and a steep hillside.

The available access to the property was only approximately 4.3 feet wide, leaving very little room to bring drilling equipment into position. Once the equipment was on site, the slope created another significant challenge. The drilling area had an approximately 70% slope, requiring careful positioning and stabilization of the rig.

Stabilizing the Drilling Rig on the Hillside

Because of the steep terrain, the drilling rig had to be supported with chains anchored into the ground to help stabilize the machine while drilling.

The subsurface conditions presented another challenge. The soil was extremely stiff and hard, requiring substantial drilling effort. Some of the caissons reached depths of more than 50 feet using a 36-inch auger.

Fortunately, groundwater was not encountered during drilling. The absence of groundwater helped simplify the drilling operation and allowed the crew to continue working through the difficult soil conditions without the additional complications that water can create during deep drilling.

This project demonstrates Zone Bolt's ability to perform deep caisson drilling in extremely limited-access and steep hillside conditions.