Chimney Rock Road and South Rice Avenue Bridge Replacements Over Brays Bayou

CobbFendley was selected by the Harris County Flood Control District (HCFCD) to provide plans, specifications, and construction phase services to replace bridges over Brays Bayou as part of the federally funded Project Brays Flood Reduction Program in cooperation with the U.S. Army Corps of Engineers (USACE).

The project included the reconstruction of 4 bridges with intersections adjacent to the bridges. The bridge profiles over Brays Bayou were raised approximately 5 feet to take the bridges out of the 100-year flood level, impacting the intersections with South Braeswood. Raising the roadway profiles had impacts to the intersections, required reconfiguring the traffic signals, crosswalks, and hike/bike trails. To keep the overall bridge profile as low as possible, box beams were used for the 215-ft long bridge at South Rice and the 230-ft long bridge at Chimney Rock. The project required coordination with the City of Houston for establishing bridge traffic lane configuration, traffic signal patterns, temporary traffic signals and relocating a force main that ran under the bayou. Per the HCFCD’s request, the force main and water lines were to be attached to the side of the box beams, requiring special modification of the standard box beams. Box beams were modified to provide a flush exterior faced, and CobbFendley provided custom reinforcing with a threaded head cast into the box.

The project required extensive coordination with the City of Houston, HCFCD, AT&T, USACE, Texas Medical Center, Houston Independent School District, Metropolitan Transit Authority of Harris County, private utilities, homeowners associations, and adjacent business. The CobbFendley team held weekly meetings, developed exhibits with bridge alternative for agency approvals, renderings for public meetings, and assigned dedicated, in-house utility coordinators.

The congested urban roadway was not conducive to elevating existing intersections and construction impacted all adjacent driveways and traffic signals. To resolve these challenges, the CobbFendley team developed diligent traffic control plans that provided access to properties at all times and developed exhibits for temporary construction easement at driveways for homeowners and businesses. Bridge construction was phased to allow the maximum amount of bridge deck to be built for the traffic switch.

CobbFendley’s Structural Engineering team reduced bridge width by using 11-foot lanes, saving almost 1,000-square feet of deck. By using single, 84-inch drilled shafts in lieu of using smaller shafts on footings, resulted in a $100,000+ total project savings.