At six stories, Sierra Pines II is the tallest building constructed with load-bearing tilt-up concrete in Texas. Because there was no precedent for a tilt-up structure of this magnitude, the team relied on LJB’s tilt-up expertise and ingenuity to design the right structural solution for this project.
The 154,000-square-foot office building is vertical in its proportions, which differentiates it from many tilt-up projects. The building’s six stories were constructed with a lower four-story panel and a two-story panel stacked on top.
The joints in the panels aren’t vertically aligned, which architecturally breaks down the scale of the building. A ribbed finish, large amounts of glass at the corners and entryway, and sunshade elements add to the architectural appeal of this Class A office building.
Once designed, innovative thinking on the construction side furthered the project’s success. For example, the project had originally been engineered using standard guidelines to utilize three 52-foot-tall braces per lower panel. By switching to higher-strength braces, and helical ground anchors to take full advantage of the capacity of those braces, it was possible to eliminate one brace per panel, or 33 percent of the braces. In addition to reducing the number of braces per panel, the team was able to reduce the length of the braces from 52 feet to 42 feet. This reduction translated to additional savings on freight.
The project was divided along its east/west axis for the purpose of construction sequencing. Planning concrete placement for a specific segment of the project allowed for the removal of the braces along the south of the building, dramatically relieving site congestion. With those floors constructed, crews were able to begin interior framing and worked to rough-in the vast majority of the mechanical, electrical and plumbing on the south side while concrete placement on the north half continued. This accelerated construction, which took only 11 months.
At the 2015 Tilt-Up Achievement Awards, the Tilt-Up Concrete Association named Sierra Pines II an Excellence in Achievement winner—an entry that scored highest in architectural and engineering creativity and construction ingenuity.