The north end of the Las Vegas Strip will host up to 80,000 people a day for the two-weekend music extravaganza known as the Rock in Rio festival in May at the MGM Resorts Festival Grounds currently under construction. But what many patrons won't see is an underground network of utilities and access points for the $40-million project, all built within a tight seven-month construction window.

While the massive footprint was a challenge to the construction team, the sheer scale was further complicated by the fact that the resulting facility will need to serve not just Rock in Rio, but a multitude of end-users over the life of the site.

"All of the players have been in every meeting together to make sure no stone is unturned," says Guy Martin, senior vice president with Martin-Harris Construction, the project's general contractor.

The Big Details

The 47-acre site, which is at the southwest corner of the intersection of Las Vegas Boulevard and Sahara Avenue, will also host Rock in Rio festivals in 2017 and 2019. The site will also give MGM Resorts the flexibility to meet the demands of various other long-term uses for the venue. Most of the site has stood vacant for several years and was the subject of various failed plans for development over the past decade. A portion of the RV park to the north of the Circus Circus Hotel & Casino was also cleared to make way for the festival grounds.

The meager collection of permanent buildings on the site include three block masonry-framed bathrooms totaling 7,500 sq ft. Each of the men's restrooms includes approximately 40 flushless urinals that Leone says are accompanied by several traditional urinals to allow for the ability to flush the lines with water in case the volume of users necessitates it.

"The basic idea is to take the kind of bathrooms that you may see in a public park and put in on steroids," Leone says.

The vast majority of work, however, was done below ground and in support of the type of events that can draw 80,000 concertgoers. According to Martin-Harris, crews moved nearly 107,000 cu yd of earth, installed 5,400 linear ft of underground raceways and placed 7,500 linear ft of data loop.

The raceways can move wires based upon the dynamics of the event being held and are accessed by more than 40 pull-boxes that were also constructed at various strategic spots throughout the site.

Water service is provided by a 6-in. pipeline to Las Vegas Boulevard and an 8-in. pipeline to Sahara Avenue. Altogether, a 6,536-linear-ft water-service loop was constructed to serve nearly any spot on the site. The 5,592-linear-ft sewer system varies between 8-in.-dia and 10-in.-dia pipe. The system is sized 15% larger than current needs require in order to allow for future expansion.

Above the underground infrastructure, Martin-Harris and subcontractors including Tracy & Ryder and Aggregate Industries are installing 527,000 sq ft of artificial turf and 664,357 sq ft of asphalt to differentiate the pathways from seating areas inside the concert viewing area.

Martin-Harris is also overseeing construction of mat foundations to support facilities that Rock in Rio will later assemble, including eight delay towers that will house lighting and sound equipment. Another mat foundation anchors a zip-line attraction that Rock in Rio will make available for their guests.

Martin-Harris is also supervising the construction of the piles and supports that will anchor the five stages for the event. The main stage will be nearly 40,000 sq ft, and the "sunset" stage will be nearly 10,000 sq ft. Three other stages vary in size from 1,250 sq ft to 1,600 sq ft.