Liebherr crawler cranes complete dynamic compaction on highway improvement project

The dynamic compaction experts at Densification, Inc. provide developers with cost-effective solutions to improve poor-quality soil or fill during construction; the team has performed high-capacity jobs across the U.S. and the Caribbean. Now, the company has been tasked with completing a major project along U.S. Route 191 with the help of Liebherr crawler cranes. 

Operating on tough terrain 

Frequent drivers along U.S. Route 191 are familiar with the 2.6-mile stretch of switchbacks located just north of Vernal, Utah. To improve this stretch of road and make it safer and more efficient for motorists and semi-trucks, the Utah Department of Transportation began the U.S.-191 Realignment Project to provide standard horizontal curves, optimize grades, and eliminate switchbacks for the highway.

The project began with the dynamic compaction of the uncontrolled embankment fill along the proposed realignment through an active sulfate mine through the existing highway. Densification was brought in to perform dynamic compaction along the alignment, performed by two HS 8100 HD duty cycle crawler cranes working in tandem. The cranes utilized 18-ton (19.8 USt) weights dropped from a height of approximately 70 feet, and an 11-ton (12.1 USt) weight dropped from a 20-foot height to complete the final ironing pass.

In the HS 8100 HD, a key feature is Liebherr's control system that lifts the drop weight to a pre-defined height and releases it in free-fall mode using both winches simultaneously. The winches then brake automatically to prevent damage to the wire ropes. This process is repeated until a present number of drops or the desired compaction depth is achieved. 

Liebherr assisted in the planning stage 

The moderate slope of the site added an extra challenge for the compaction company. From start to finish, there was a 500-foot elevation change that Densification had to accommodate to safely operate their machines.

To assist, Liebherr created a custom load chart for the project's unique specifications which provided the operators with the proper load capacities to complete the job safely and efficiently.

"We're confident in our ability to stay on schedule and provide our clients with the best dynamic compaction solutions possible due to our HS 8100 HDs consistent performance and durability," notes Shaffer.

Densification specializes in compaction jobs 

Dynamic compaction creates solutions for soil densification and involves multi-ton weights being dropped repeatedly to create a shock wave that increases the density of the soil. Having completed over 1,000 projects since its founding, Densification has the expertise and equipment to properly supply effective soil densification to sites across the nation due to its crane fleet including multiple Liebherr HS 8100 HD duty cycle crawler cranes. 

Robert Shaffer, vice president of Densification, Inc. said, "Part of our decision to purchase and use Liebherr HS 8100s HDs was based on Liebherr's reputation for durable, dependable cranes."