DFW Connector Design-Build Project in Dallas, Denton, and Tarrant Counties, Texas
IEA provided various design services for this $1.0 Billon design/build project. These services included structural design, drainage, utility relocation designs, 3D modeling, toll integration, and life cycle cost analyses.
Life Cycle Cost Analyses:
IEA staff performed extensive Life Cycle Cost Analyses (LCCA) for the capital and routine maintenance assets. Evaluation included analyzing initial costs and discounting future costs, such as maintenance, user, reconstruction, rehabilitation, restoring, and resurfacing costs, over the life of 50 years. IEA staff utilized industry standard LCCA software and spreadsheets to determine the best value. The LCCA process also included interviews with personnel from design, construction, and maintenance teams.
During the proposal phase, IEA prepared site adaptation plans for the tolling infrastructure of managed lanes. Tolling sites included gantries, barriers, foundations, equipment cabinets, buried conduits, backup power, signage, and maintenance access.
IEA provided project wide drainage design for the DFW Connector. The limits of the drainage design include SH 114 from Kimball Avenue to Main Street, SH 121 from Hall Johnson to where it merges with SH 114, SH 26 from Kimball Avenue to the east of Baylor Pkwy, SH 360 from south of Stone Myers to SH 121, FM 1709 from west of Gateway Drive to SH 114. IEA’s responsibilities included the research and development of project specific drainage criteria and standards, establishment of existing conditions through site visits and record document research, setup of Geopak drainage software database specific to project standards and drainage criteria, design of drainage details necessary for project needs, coordination of drainage elements with TxDOT, area FEMA flood plain managers, and other agencies or project partners, coordination of design with all other disciplines (structures, roadway, geotechnical, etc.), and writing of the hydraulic report for the DFW Connector and other reports necessary for permitting.
The drainage design included 7 stream crossings with bridge class culverts, 5 detention ponds, and closed and open drainage systems. The schematic design recommended large detention ponds outside the proposed Right-of-Way (ROW). IEA’s innovative drainage design eliminated the need to purchase ROW beyond the proposed ROW lines.
IEA calculated hydrographs and peak flows using HEC-HMS (v3.3) and Geopak drainage, HEC-RAS (v4.1.0), and HY-8 were used for hydraulic analyses. Detention routing calculations were completed using HEC-HMS.
IEA provided utility coordination and wet and dry utility design services for utility relocations. Utility relocations included communications, water, sewer, and cable lines.
IEA was part of the Structural Task Force for this project. IEA assisted in developing the bridge design directives and General Notes Sheet in conformance with TxDOT and CDA design guidelines for the project. IEA’s expertise in TxDOT bridge design was used to review the calculations prepared by the bridge design team. A total of 40 bridges, including 14 Direct Connectors were designed for the project. The majority of the bridges were part of four multi-level interchanges along the SH121/SH114 corridor. The review of all plans was performed at each submittal, checking for any issues with the calculations and consistency among the designers where required.
IEA performed 3D modeling for this project. The 3D model provided the basis for construction. The contractors used this 3D model for project layout/staking, scheduling and allocating resources required to build the DFW connector.
IEA was involved in construction management for this project. IEA provided construction inspections and commissioning for illumination systems, fiber optic systems, CCTV cameras, and toll gantries.