Structural steel work has advanced passed the 50th floor on the new Wilshire Grand Center in Downtown Los Angeles. Scott Borland, vice president and construction executive for Turner Construction Co., the project's general contractor, says there are currently about 550 to 600 workers onsite, most of which are superstructure trades people working on the massive concrete core for the planned 73-story mixed-use tower.

Developed by Korean Air Lines Co., the new, roughly $1 billion hotel and office project will rise to 1,100 ft tall, making it the tallest building west of the Mississippi River when it completes in early 2017. The tower will be capped with a distinctive architectural spire at the top.

The approximately 2 million sq-ft development was designed by Los Angeles-based architect AC Martin Partners and Structural engineering is being led by Brandow & Johnston Inc., Los Angeles.

The Wilshire Grand is highlighted by a concrete core, surrounded by a single-span glass curtain wall. The core will hold the elevator shafts serving the 900-room hotel. Below the hotel will be 400,000 sq-ft of office space and more than 45,000 sq-ft of retail. An 1,100-stall parking garage will occupy seven levels below grade.

The concrete core will help stabilize the building in case of seismic events. Adding to the structure's support will be the use of three levels of buckle-resistant braces (BRB) which are attached to the concrete core.

The project is currently between 45 - 50 percent complete, with the exterior curtain wall now passing the 23rd floor of the tower; light framing and roughing walls underway on the lower tower; and the concrete slab on metal decks are passing the 35th floor. Borland says crews are erecting a new floor every four days.  

The superstructure concrete contractor is Conco of Fontana, CA; Gerdau of San Bernardino, CA is the concrete reinforcement contractor doing rebar work; and Phoenix, AZ-based Schuff Steel is fabricating and erecting the structural steel.

Borland says the next biggest milestone for the project will be when the concrete core tops-out in mid-February 2016, followed in April with the structural steel topping out to the 73rd floor. He says after this the next milestone will getting the signature "sail" spire feature on top of the building up in mid-September 2016.  

The spire atop the structure will stand next to a tactical approach helicopter pad and will be a source of pride for the architects. Chris Martin, CEO of AC Martin Partners, told me in 2013 that this project, with its iconic spire, is a "big deal because my grandfather did L.A. City Hall in the 1920s, and that is the only other building in the city that really has an architectural top." He said all the buildings in L.A. have flat, truncated tops, "so this is going to stand out—and we want it to."

The project is located on the site of the former Wilshire Grand hotel, which closed in 2011.