Rotting Retaining Wall Replacement Poses Challenges

Mon March 28, 2005 - Southeast Edition
Construction Equipment Guide

As a design/build contractor, Southeast Landscape Management in Dawsonville, GA, specializes in unusual custom residential projects.

“We do work that other companies either don’t want to do or can’t do,” said Chris Nicholson, president of the company.

Nicholson and his partner, Tim Costely, president of sister company Southeast Arbor Management Inc., have been doing this work for 11 years. Starting with their first skid steer loader, a 743, they’ve used Bobcat compact loaders and a variety of Bobcat attachments to handle digging, grading, carrying and loading chores. Current Bobcat equipment includes two S250 skid steer loaders and a T190 track loader.

“We’re creative,” Nicholson said.

A recent project replacing a rotting timber retaining wall on the side of a steep slope with a pre-cast concrete block structure illustrates how the company successfully uses its creativity to complete difficult projects.

The 200-ft. long (61 m) wall, built of railroad ties and standing as high as 12 ft. (3.7 m) in places, was retaining red Georgia clay soil, which supported an asphalt driveway.

“Our main concern was safety,” Nicholson reported. “The site was more than 100 feet above the lake below it. There was no room for equipment to work on the wall from the side of the slope and we didn’t want to risk a collapse of the wall if we placed machines on the driveway to work from above.”

A rented Bobcat 337 excavator, equipped with a bucket and hydraulic clamp, played a key role in dismantling the wall. Nicholson placed the 337 at one end of the wall and used the machine to remove the ties and the original fill behind it as he worked his way to the other end. Along the way he laid the slope back far enough to minimize any collapse of the excavated slope. When he was finished, he had an 8-ft. wide (2.4 m) ledge upon which he and his crew could build the new concrete block retaining wall.

“Attacking the wall from one end went like clockwork,” Nicholson said. “The 337 was small enough to fit the job while giving us the stability and power to lift three or four cross ties at once. I’ve used all sorts of equipment and this is one nice machine.”

It also had the reach to place the ties and the soil far enough back from the edge of the top of the excavation for safe removal. In addition to handling all the dirt on the project, the S250 carried and placed approximately 68 tons (62 t) of gravel and all the blocks needed to build the wall, which has a 900-sq. ft. (84 sq m) face.

“The S250s are our best money-making tools, period,” Nicholson said. “We use them for everything. They’re light enough to get into any job site, yet they have the power we need to do the job. The optional two-speed [12 mph in high range] is a great feature. Many of our jobs involve long travel distances [as much as 30 minutes round-trip]. That extra speed means one machine can do the work of two in the same amount of time.”

(This story was reprinted with permission of Bobcat’s WorkSaver magazine, from the Fall 2004 issue.)