Success in Steep Conditions With Liebherr Crawler Cranes

Mon March 17, 2025
Liebherr

With the help of two Liebherr HS 8100 HD duty cycle crawler cranes, Densification Inc. completed an extensive dynamic compaction program to provide a solid foundation for a safer stretch of highway along the US Route 191 corridor.

Founded in 1994, Densification Inc. strives to provide property owners and developers with a cost-effective solution when encountering poor quality soil or fill during construction. Through the years they have become a premier dynamic compaction contractor, performing jobs across the United States and the Caribbean.

Dynamic compaction serves as an innovative and sustainable solution 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 more than 1,000 projects since its founding, Densification has the expertise and equipment to properly supply effective soil densification to sites across the nation thanks to their extensive crane fleet including multiple Liebherr HS 8100 HD duty cycle crawler cranes, according to Liebherr.

As one of the only companies in the United States using these machines for this application, Densification has seen the versatility of these machines first-hand and found a trusted partner in Liebherr.

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."

Realigning Rough Terrain

Frequent drivers along US Route 191 are familiar with the 2.6-mi. 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 US-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 which the existing highway alignment traversed. Densification was brought in to perform dynamic compaction along the alignment, which was performed by two of its HS 8100 HD duty cycle crawler cranes working in tandem. The cranes used 18-ton weights dropped from a height of approximately 70 ft. for the high energy work and an 11-ton weight dropped from a 20-ft. height to complete the final ironing pass.

For dynamic compaction, HS 8100 HD key features include Liebherr's advanced 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 brake automatically to prevent damage to the wire ropes. This process is repeated until a preset number of drops or the desired compaction depth is achieved. In addition, the operator's cabin is equipped with armored glass to ensure the operator's safety.

While this project was like the type of infrastructure projects Densification has been performing for decades, there was one variable that made this project different from all the others and that was the moderate slope of the site. From start to finish, there was a 500-ft. elevation change that Densification had to accommodate for to safely operate its machines.

Because of this, Liebherr created a custom load chart for the project's unique specifications. The custom load chart provided the operators with the proper load capacities to complete the job safely and efficiently, according to Liebherr.

"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," said Shaffer.