State Highway 130
S&B Infrastructure, Ltd. (S&BI) performed schematic preparation and final design for the State Highway 130 Toll Road. This toll road is the single largest highway project in Texas and one of the largest design-build highway projects in the United States. SH 130 (Segments 1-4) is a new 49-mile tollway located east of I-35 through Williamson and Travis counties, extending from I-35 north of Georgetown to U.S. 183 southeast of Austin. SH 130 is a four-lane divided facility with major interchanges at IH-35, U.S. 79, SH 45 North, U.S. 290 and SH 71. Ultimately, SH 130 will become a six-lane facility with a median capable of accommod-ating future transportation options such as rail.
SH 130 is also the first State Highway project in Texas to be built under an Exclusive Development Agreement (EDA), allowing the work of property acquisition, design and construction to be undertaken simultaneously. When completed, this toll road will extend from east of IH 35 from Georgetown to IH 10 near Seguin (a total of 91 miles), relieving congestion on IH 35 and other major roadways in the Austin-San Antonio corridor.
SH 130 includes 177 structures, seven major interchanges, and 7.6 million-square-yards of concrete paving. The ultimate design for SH 130 includes three mainlanes of travel in both north- and south-bound directions with three-lane frontage roads. The alignment and proposed median width were designed to accommodate future transportation needs such as general multi-purpose lanes, high occupancy vehicle (HOV) facilities, and light rail transit.
S&BI quickly mobilized for this project by staffing up to 75 FTEs in less than four months, including setting up IT systems, developing design standards and implementing QA/QC procedures.
S&BI developed schematics for the entire route (Segments 1-6) and final drawings (Segment 1-4) for 49 miles of toll road and 116 bridges in the interim condition. Schematics included the development of final schematics for both the interim and ultimate conditions for the entire route.. These included incorporating all changes, such as accepted alternate technical concepts, developed in the proposal stage. As well, provisions for Right-of-Way and access control were finalized. The final design drawings were developed for the interim condition in the form of a grade and drain package utilizing Geopak and Microstation. Project design challenges included complex geometrics for horizontal and vertical alignments and the optimization of cut and fill volumes through rolling terrain. S&BI prepared roadway typical sections, pavement section tables, horizontal alignment and superelevation data sheets, plan and profiles, intersection layouts, cross sections and earthwork computations. S&BI was also responsible for coordination of TxDOT specifications, special provisions and general notes project wide. S&BI’s structural engineers were part of the team that provided structural design, bridge layouts and final PS&E for 66 structures that included bridges, bridge class culverts, and interchange direct connectors. Design included foundation layouts, column and bent design, bridge aesthetics detailing, steel and pre-stressed concrete design, beam design, and slab and approach slab details and design. Also provided details for retaining wall design. S&BI was responsible for drainage design plans, including hydrologic modeling and hydraulic data, that spanned four counties and included 25 watersheds totaling more than 40,000 square miles. The project limits encompassed 37 waterway crossings, of which, 25 were in Zone A, and 12 were in Zone AE. Each waterway was modeled to determine the impacts of proposed improvements on flow characteristics and water surface elevations utilizing HEC-HMS, HEC-2, WSPRO, TR-55, TRAP and HEC-RAS. Storm water pump stations were designed. SBI staff developed drainage design that included internal storm sewer systems, channel improvements, temporary and permanent BMPs, including grass swales, vegetative filters, rock filter dams, water quality ponds and incorporated these measures into the storm water and erosion and sedimentation control plans. The project crossed the environmentally sensitive Edwards Aquifer recharge zone and a Water Pollution Abatement Plan was prepared and submitted to TCEQ.
S&BI was part of the Public Information team and worked directly with TxDOT counterparts and consultants to provide a multi-faceted public outreach program that included an aesthetics charrette process, media relations, Website development, newsletter publication, citizen inquiry management, a speaker's bureau, and traffic notices.
Construction Design Coordination
On a design-build project such as SH 130, the Construction Design Coordination was infinitely more crucial than under the traditional design-bid-build scenario, as construction activities were underway before the design was 100 percent complete. S&BI was actively involved in the Construction Design Coordination, and met the significant demands of this coordination effort through constant contact between design engineers and construction personnel.
S&BI also developed the floodplain report format for Zone “AE” studies in an effort to standardize the contents of all such reports. S&BI also developed a Design Task Protocol (DTP) for Zone “A” (Designated) streams that outline the procedures and methodologies to be followed when developing a floodplain study. SBI developed and tracked schedules for each Zone “A” and “AE” flooplain study and developed checklists for submittals to the Design Quality Assurance Firm (DQAF). The S&BI Team has also continually acted in a proactive manner to minimize excessive revisions and comment periods, which prevented several delays to the project. The S&BI Team coordinated with the city and county entities to help identify community improvement projects within the areas of study that might impact the floodplain analysis.