FROM DUGOUT TO DIAMOND

BY ERIN PINKERTON

The official groundbreaking for Globe Life Field, the new home for the Texas Rangers, was September 28, 2017. A week later, crews were on-site to begin the excavation, which would eventually include more than 1.3 million cubic yards of dirt. To accomplish this large-scale excavation, crews worked 24/7 for months and hauled away an estimated 97,000 truckloads of dirt, said Alan Dunnam, senior superintendent at Manhattan Construction.

Before excavation could begin, crews had to clear the site, which included moving existing underground utilities, demolishing an old parking lot and closing and removing part of Nolan Ryan Expressway.

During excavation, crews ran into granite boulders that were the size of houses and had to be broken down using large hydraulic hammers and then hauled away.

“We had to get a lot out of the way so we could go all the way down to the field level,” Dunnam said.

Excavation crews also dug up an old, abandoned gas line that ran through the site but hadn’t been on anyone’s radar, according to Collin Lane, senior project engineer at Manhattan. Manhattan reached out to the natural gas distributor to make sure the pipeline was no longer in use.

“We kind of knew it wasn’t, but we had to verify what it was, who it belonged to, and that it didn’t feed anything or service anything,” Lane said. “Then we capped it and excavated the rest out of the footprint of the building.”

In all, about 1,200 loads of material were hauled from the site every day, with 70 to 80 trucks running 24/7 between the project site and the landfill, Lane said. As crews hauled away more and more dirt, that left more and more space for water to fall or seep into.

“Any time it rains, you’re basically digging a massive, 20-acre lake,” laughed Shane Griffin, project manager at Manhattan.

“We were digging right next to Johnson Creek, and our final elevation was actually lower than that creek. As you start digging, groundwater seeping in becomes a big issue in terms of being able to safely excavate or to safely perform the work,” Griffin explained. “I think our team did really well at managing that and choosing when to shut down for safety and push forward when we had the opportunity.”

As the excavation contractor dug deeper, a retention system contractor built a retaining

wall to keep the dirt on the sides of the hole from collapsing into the hole. The two teams worked in tandem, digging and retaining layer by layer, which Lane described as similar to making a multi-tiered cake — only upside down.

“There’s a lot of coordination, and your timing is everything,” Lane said. “It’s kind of a back-andforth dance between those two to bring all the walls down to elevation.”

The excavation contractor would dig out about 5 feet of dirt, then the retention system contractor would follow behind and build parts of the retaining wall. This back and forth between the two contractors continued in 5-foot lifts until they hit the bottom, where the ballfield sits today, at about 50 feet below street level.

The retention system was built with mesh fencing that was anchored in place by soil nails. The nails were about 50 feet long, and grout was injected into the drilled hole around the nail. Then the mesh and anchors were covered with 5 inches of shotcrete, or sprayed concrete.

The retention system stretches 5,184 feet — just under 1 mile — around the perimeter of the ballpark’s footprint, said Brett Young, senior project engineer at Manhattan. The system also required more than 10,000 soil nails, he added.

The first piece to go up after excavation was complete was a 14-inch-thick concrete wall that Manhattan built with its own crew.

“That wall coming back up after you get to the bottom kicks off your structure, so you can’t do anything until you get that wall high enough that your structure doesn’t block you. It’s a race to the bottom, then a race back up to the top, with this finished wall in front of it,” said Griffin, who managed Manhattan’s concrete team. “We’re fortunate enough to have some very experienced

carpenter foremen and labor foremen who had experience with this exact system.

“From our team’s aspect, it was a huge push and a big success that we self-performed the concrete, and we were able to drive the schedule of the project early on to get other trades into the building sooner,” he said.

This includes Capform, the concrete contractor responsible for forming and finishing the main concrete structure, according to Dunnam. Capform’s work included cast-in-place columns, sheer walls and slab-on-metal decks, and consisted of about 115,000 cubic yards of concrete, according to Dunnam.

IT’S AMAZING HOW QUICKLY THE TIME HAS GONE BY. WE’RE REALLY GETTING EXCITED ABOUT SEEING THE FINISHED PROJECT AND WELCOMING OUR FANS THIS SEASON.

–ROB MATWICK, EXECUTIVE VICE PRESIDENT, TEXAS RANGERS

“We were there from the get-go when they were starting out with the piers all the way until they were topping out the steel structure,” said Jose Avila, project manager at Capform. “As things were getting turned over by the steel guys, we were pouring concrete on top of their steel. It was going hand in hand with the main structure, the concrete and the steel.”

Crews ran into a bit of trouble when they tried to set anchor bolts — 4 feet long and 3 inches in diameter — to attach the structural steel to concrete that was heavily congested with rebar.

“There was so much rebar in these pan decks that our first main concourse pour actually took 1,500 man hours to put the anchor bolts in for the steel, and that was only about 20,000 square feet,” Young said. “It was an outrageous number of manhours for that.”

Manhattan went to Walter P Moore, the project’s structural engineer, for help. Walter P Moore was able to use 3D modeling to find solutions for setting the anchor bolts amid the reinforcing steel.

Cooperation among the various trades and Manhattan’s all-hands-on-concrete-deck approach are what make a project like Globe Life Field possible.

“It required a buy-in from a lot of people to actually get the work done on time. It was just a joint team effort between Manhattan and all of our subcontractors,” Young said.

“Being a part of this project, many of us get to put another feather in our cap,” Avila said. “We look back with this thing completed and think, ‘This is one, for sure, for the books.’ To be able to do that with Manhattan and the other team members that were associated with this project, it’s rewarding.”