Offsite manufactured Bridges IDEAS FOR FAST, SAFE AND EFFICIENT BRIDGE CONSTRUCTION Tomas Garcia Principal Bridge Engineer at CH2M

Index OVERVIEW DESCRIPTION CONSTRUCTION EXAMPLES

OVERVIEW

Industry: Shortage of skills High demand

...Is there any other way? Fast Simple Inexpensive ...but Maintenance? Typical case Fast Simple Inexpensive ...but Maintenance? Aesthetics? Functionality? ...Is there any other way?

2. DESCRIPTION

Different way to build continuous precast decks

Main characteristics of BSST precast continuous bridges Continuous U-beam bridge decks, made up of: Precast prestressed spliced U-beams (pretensioned and/or post-tensioned) Cast-in-place reinforced and/or post-tensioned concrete top slab, using free-standing planks. Three main elements: - U-girder (close the span between supports, its shape enables to have enough space inside to do the continuity in an easy way, and other possibilities that we will see after), - free-standing precast-planks (structurally not relevant, but very important to get an easy & fast construction process) - cast-in-place concrete slab (it makes possible the composite action of all elements, and also to get easly the final top surface. The concrete poured over the planks, it is also an economical material to work with on site)

3. CONSTRUCTION

Simple planks for Two U-girder section Enhanced planks for long spans

Description of BSST system Continuity by means of post-tensioning: tendon or bar

Continuity by unbounded elements

UPPER SLAB by FREE-STANDING PLANKS and pouring fresh concrete on site. Construction sequence of BSST UPPER SLAB by FREE-STANDING PLANKS and pouring fresh concrete on site. - get a fast surface to work on it - increase of safety on top slab tasks

4. EXAMPLES

Alternative arrangements If required, monolithic connection to piers.

Alternative arrangements Monolithic cross head, in extreme skewed crossings. Precast capping beam + two U-girders at each side, with post-tensioning through them.

Constant/variable depth or width (straight or curved haunches) Straight or curved beams

Design and construction solutions for complex geometries: “Fork” type decks Decks with a great variable width

QUESTIONS ?

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