Greens Bayou Trail Phase 2

Identified as a top priority during the development of the District’s Parks Master Plan, this portion of trail was the first phase of over two miles of planned trails to provide connectivity and recreation for District residents.

Meridiana

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.

Ventana Lakes Development

Project totaled 640 acres including 1256 Residential Lots. EHRA designed, created construction plans, publicly bid and preformed Construction management.

Northpark Drive Mobility Project

EHRA completed preliminary engineering, phase one environmental site assessment and schematic development for the widening of Northpark Dr. between US 59 and Woodland Hills Dr. EHRA also provided program management, drainage analysis and design, traffic engineering, environmental documentation and schematic design for the roadway, as well as grade separation at the Loop 494/UPRR railroad crossing.

EHRA conducted traffic operations and access management studies for the Northpark Dr. corridor. This corridor is approximately 2.2 miles long and has major signalized and unsignalized intersections and driveways that access various subdivisions and industrial developments. These studies laid the groundwork for the widening of Northpark Dr. from a four-lane boulevard cross-section to a six-lane boulevard complete street. The new street design includes low impact development drainage, conventional drainage, a grade separation at the UPRR crossing with mechanically stabilized earth retaining walls, two at-grade crossings for bi-directional frontage access, reconstruction of two concrete bridges over a diversion channel, intersection improvements, a roadway-adjacent multiuse path and traffic signal improvements.

Drainage analysis and design included hydrologic and hydraulic studies of both existing and proposed conditions to demonstrate that proposed project components would not adversely affect the 100-year floodplain in the area. The roadway and traffic designs contained horizontal and vertical alignments, cross-sections, plan and profile, sidewalk and bicycle accommodations, intersection layouts, traffic control plans and signing and pavement markings.

As the program management firm, EHRA coordinated with TxDOT, UPRR, the City of Houston Council District E, COH Planning and Development Department, COH Public Works and Engineering Department, Montgomery County, Harris County, HCFCD and area residents throughout the project.

Cutten Green Park Northwest Harris County MUD No.6

This project was the second phase of parks implementation outlined in the District's Parks Master Plan, which was completed by EHRA in 2007. Utilizing the site of a recently demolished former wastewater treatment plant provided an opportunity to create a passive park space for District residents.

22 December 2017

Biomechanical Model Could Reduce Pedestrian Bridge Wobbling

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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.