IH-70 Ramp A
Life-Cycle Engineering Services | EXPANDED

Modjeski and Masters is pleased to announce the acquisition of structural engineering firm Summit Engineering Group, Inc. Our combined engineering prowess and respective technical skillsets will enable us to provide streamlined design and construction solutions to best meet client needs.

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Sylvan Avenue Bridge Replacement

| Dallas, TX

  • Client:

    Webber and Bexar Concrete Works, LTD.
  • Service:

    Construction Engineering
  • Status:

  • Overview

    The previous Trinity River crossing consisted of three separate bridges. Two of them crossed the east and west levees, and one low-water crossing bridge over the Trinity River. With the Trinity River crossing sitting at such a low elevation in the Trinity River floodplain, it became impassable at times of high water, accentuating the need for a new, more hydraulically efficient crossing. The new bridge raises the profile of Sylvan Avenue out of the floodplain. In fact, the crossing is built above the 800-year flood elevation providing uninterrupted traffic flow year round.

    The new Sylvan Avenue Bridge is a 23-span bridge that incorporates context sensitive features such as ornamental lighting, open railings, and a ramp which allows both vehicular and pedestrian access to Trammell Crow Park and its soccer fields below. It is composed of precast concrete I-girders and spliced post-tensioned girder for the longer spans over the river crossing. There are 3 post-tensioned units, each consisting of 3 spans. The typical post-tensioned I-girder is 6’-10” deep with some of the I-girders having a variable depth between 6’-10” to 10”-10”.

    Summit Engineering (Summit) provided construction engineering to the contractor and developed shop drawings for the precaster for the spliced, post-tensioned units. This type of construction was relatively new to TxDOT and the City of Dallas. Summit provided the engineering knowledge and experience in this type of construction that helped bridge the gap between contractor, engineer of record, owner and precaster. Summit introduced a number of innovative concepts to enhance the constructability of the project. To reduce construction costs, Summit developed an integral corbel system to support the girders during construction of the post-tensioned units. This eliminated the need for external strongbacks at 132 total splice locations and enabled all of the bridge girders to be erected in a single phase of construction. Summit provided construction engineering services for the contractor including design of all falsework, integral corbel supports, girder bracing, lifting equipment, and rigging.

    Summit Engineering is proud to have been a part of this challenging bridge replacement project. Our construction engineering innovations seamlessly integrated into the bridge’s construction process. The result is a structure that preserves and enhances scenic, aesthetic, community, and environmental resources, while improving the safety and mobility of the travelling public.
  • Description

    Tasks Performed
    • Construction Engineering
    • Erection Engineering
    • Falsework Design
    • Structural Analysis

    Bridge Geometry
    • Length of Main Span – 200 & 250 feet
    • Total Project Length – 3,500 feet
    • Lanes on Existing Structure – Six Lanes, Two Sidewalks
  • Testimonial

    The new bridge preserves and enhances scenic, aesthetic, community, and environmental resources, while improving the safety and mobility of the travelling public. - Gregg A. Reese, PE, President, Summit Engineering Group
  • Credits

    Gregg A. Reese, PE (Project Principal)
    Construction Engineer to the Contractor and Precaster