Using trench cutter technology, Bencor installed deep reinforced concrete diaphragm walls through severe geologic conditions in record time.

The Project

The severe geologic conditions (Caliche rock of strengths up to 20,000 psi) encountered in the Las Vegas Valley lend themselves perfectly to the installation of deep reinforced concrete diaphragm walls by the use of trench cutter technology. In order to achieve the installation of over 300,000 square feet of slurry wall in 6 months time, Bencor mobilized 4 hydromills, 3 operational, and one standby. This equipment proved effective for excavation through the difficult Caliche rock layers. Never in the history of North American deep foundation installation has a 6-level subterranean parking structure been successfully installed using the diaphragm wall technique in such a short time period.

The Solution

Bencor installed approximately 330,000 square feet of reinforced concrete slurry walls with a thickness of 30 inches and to a depth of 105 feet using 3 reverse circulation trench cutters (hydromills). Bencor fabricated the reinforcing steel cages on the 8 acre jobsite, then installed the cages and the approximately 12,000 cubic yards of 4500 psi concrete via tremie. The jobsite logistics of coordinating three trench cutters, three separate desanding/slurry plants, the reinforcing steel fabrication, and concrete placement all under a very tight schedule was quite challenging. The entire slurry wall project was installed in 6 months.

  • Wall Type: 30 inches reinforced concrete slurry wall with approximately 3000 tiebacks
  • Wall Area: 330,000 square feet
  • Max Depth: 105 feet

Project Facts


Cosmopolitan Resort & Casino

Main Contractor(s)

Perini Building Company

Keller Business Unit(s)