The purpose of this project was to convert the existing at-grade crossing of Brazoria County Road 56 (CR 56) and State Highway 288 (SH 288) into a diamond interchange that includes a new overpass bridge and providing access to the newly developed Meridiana Development. Coordination with TXDOT, area landowners, utility companies, and Brazoria County was integral in obtaining approval and acceptance of the project. The main design challenge for this project was to accommodate double intersections on the west side of SH 288 to tie into existing access roads with two-way traffic and a new southbound on-ramp within a close proximity. EHRA coordinated with TxDOT throughout the project from preliminary concepts for the intersection and bridge through final design and construction. Each component of this project was designed in accordance with TxDOT standards and criteria.
Engineering design and construction phase services of water, sewer, drainage and paving for four subdivision sections and off-site channel (123 acres out of a 400 acre subdivision). There was 60-feet of elevation difference on this site and wooded lots were left in their natural state which required the installation of retaining walls.
EHRA assisted with the district creation of Montgomery County Municipal Utility District No. 126 to accommodate a ±329 acre master planned community located in northern Montgomery County in the City of Conroe, south of League Line Road, west of Longmire Road, and adjacent to Lake Conroe.
In 2006, Caldwell Companies sought to create Towne Lake as a community where residents and services could be connected by water. Their vision included boat docks and marinas augmenting traditional walking trails to navigate a vibrant residential community. EHRA was the perfect partner to take Caldwell Companies’ vision and create this livable suburban oasis.
A 720-acre gated master planned community located off Telge Road, just north of Willow Creek. See how EHRA was involved in this project.
The dangerous wobbling of pedestrian bridges could be reduced by using biomechanically inspired models of pedestrian response to bridge motion and a mathematical formula to estimate the critical crowd size at which bridge wobbling begins, according to a study led by Georgia State University. Many pedestrian bridges around the world have experienced dramatic vibrations and dangerous wobbling when crowds of pedestrians have tried to cross them, with some bridges falling down. Bridges all over the world have experienced this including the Squibb Park Bridge in Brooklyn that remained closed for years after wobbling.
"In this Science Advances paper, we reveal this threshold effect and show this is a general phenomenon for bridges," said Dr. Igor Belykh, professor in the Department of Mathematics and Statistics at Georgia State. "We challenge the widespread view that increasing the crowd size will gradually increase the bridge wobble. The current view is the more pedestrians we add to the bridge, the wilder the oscillations will be. This is true, but only for crowd sizes above this critical size. There is an important threshold effect.
"Our paper gives an explicit guideline and formula of how to estimate this critical crowd size, which can be used to limit the carrying capacity of an existing bridge and to help designers build better bridges. The biomechanical models we're developing are particularly important for understanding the role of crowd dynamics on a wobbly bridge because the U.S. code for designing pedestrian bridges does not contain specific guidelines that account for collective pedestrian behavior. The industry standard programs used by bridge designers only use linear models. We're working on the inclusion of biomechanical models like ours into the standard tools and software programs used by bridge designers to better predict the nonlinear effects associated with the interaction between crowds of pedestrians and bridges."
In 2014, the Squibb Park Bridge in Brooklyn, N.Y. bounced from side to side as pedestrians crossed the bridge and didn't reopen until early 2017.