River Beds

D.E. Harvey Makes Room For San Antonio Visitors

By Rob Patterson

With the completion of the new Riverwalk Suites Hotel, San Antonio will offer more accommodations to its many visitors on some of the city's choicest real estate and one of Texas' most popular tourist destinations -the River Walk.

Rising from one of the last open parcels of land adjacent to San Antonio's famous River Walk is the new 14-story Riverwalk Suites hotel. Erecting the $28 million concrete structure amid busy downtown streets, the San Antonio river and the city's historical sites wasn't easy.

"The biggest things we've had to deal with are a tight site and deliveries and staging," said Tom Freisenhahn, project manager for Houston-based D.E. Harvey Builders Inc. "Having no lay down area was a major deal to work through and we had on-time deliveries as much as possible."

Those are just some of the complexities the contractor has faced since >> breaking ground on the 266-suite, 240,000-sq.-ft. project in April 2004. The reinforced concrete structure with a center atrium is scheduled for completion in October. Harvey is performing the job under a guaranteed-maximum-price contract for a 50/50 savings split with owner Riverton Suites Ltd. of San Antonio.

Excavation went 14 ft. down from the River Walk level. "We hit all kinds of old structures, but luckily nothing that was historical," said Freisenhahn. "There was also a lot of water and underground streams." During excavation, about 500 gallons of water per hour was pumped out over a three-month period.

To support the structure, 114 piers were drilled 40 to 50 ft. into the shale below. To deal with the moisture underneath the 8-in. concrete slab, a 12--in. bed of gravel and a 4-in. mud slab was installed and topped by a membrane.

The fourth level has 4 ft. wide by 2 ft. deep concrete transfer beams with 23 post- tension cables to support the upper floors. Six 3 ft. by 3 ft. square-shaped, 55-ft. high concrete columns were built to support the fourth floor transfer beams and then removed in 8 ft. sections by a robotic saw. There are smaller transfer beams on the levels above and 70 vertical columns with post-tension cabling.

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To pour the 11,000 cu. yds. of concrete, a tower crane was placed in the center of the site inside the atrium space. A lane of traffic was closed to allow concrete deliveries at night. When finished, another 350-ton crane was set up to lift out the inside crane and tower.

The crane prevented a temporary roof from being installed. "It came out at the right time, since we were starting to work on the interior finishes. But it didn't allow us to get going as quickly as we could have," Freisenhahn said. "We had some water damage in the atrium and some of the guest rooms and sheet rock had to be replaced."

At the bottom of the atrium, 12 ft. below street level, is an interior courtyard that is level with the River Walk. During construction, a barricade protected pedestrians as well as a wall with a historical mural. The hotel's concrete structure was later tied into the top of the wall.

Along the edge of the site were three historical stone-and-concrete benches designed by original River Walk architect Robert Hugman in the 1930s. Two were protected and built around, and the city allowed the third to be taken apart and reassembled inside the courtyard and placed underneath a limestone arch. Harvey had to secure a $1 million bond to cover any possible damage to the historical features.

"We were able to preserve that bench, reconstruct it, and put it within the same sort of context it was in originally," said Carl Ede of Dallas-based Three Architecture Inc.

A River Walk wall was taken down to allow access to the courtyard. " Stone from the wall was used in the interior arch. A water feature in the courtyard adds an aesthetic tie to the river. The curtainwall on the lower level opens the atrium up to the River Walk. >>

Also on the site are also two 42-in. diameter city water wells that Harvey had to work around. Shoring was added to the well vault and steel bracing above it to accommodate future access.

Since plans for the hotel with a different operator were originally developed in 2000, Harvey had to deal with a number of change orders. The majority of those affected the rooftop, which features a pool and health spa.

The pool was changed from stainless steel to gunite, requiring larger rebar to be installed in the transfer beams below it. An expansion of the spa structure called for additional steel beams below it, which meant closing a lane of traffic below while they were lifted up and set in place.

The building's exterior is faced with limestone and concrete masonry unit on the first two levels and exterior insulation and finish systems on the levels above. "We went for a look that was a little more modern and a little quirky, but still felt like San Antonio," said Ede. "Part of that was achieved through the use of plaster, which in this case was EIFS. The look is appropriate to the Spanish influence in San Antonio."

The owners are pleased with the end result. "It's a building that reflects the nature of the River Walk, and that's what we tried to capture with the design," said John Beauchamp of Riverton Suites Ltd.