ORGANIZED BY FEUP (FACULTY OF ENGINEERING OF THE UNIVERSITY OF PORTO) IN COOPERATION WITH IST LISBON, UNIVERSITY OF MINHO AND LNEC.

Published by CRC Press / Balkema (Taylor & Francis Group)

Key Note

JIRI STRASKY

CZECH REPUBLIC

TECHNICAL DIRECTOR STRASKY, HUSTY AND PARTNERS

M.SC. AND PH.D. FROM THE TECHNICAL UNIVERSITY OF BRNO, CZECHOSLOVAKIA, DSC. FROM THE CZECH ACADEMY OF SCIENCE. PROFESSIONAL ENGINEER IN 7 STATES OF THE USA AND IN THE CZECH AND SLOVAK REPUBLIC.
PROFESSOR OF CONCRETE STRUCTURES AT THE BRNO UNIVERSITY OF TECHNOLOGY & TECHNICAL DIRECTOR OF THE DESIGN FIRM STRASKY, HUSTY AND PARTNERS, BRNO, CZECH REPUBLIC AND GREENBRAE, CALIFORNIA, USA. EXPERTISE IN CONCRETE AND STEEL BRIDGE DESIGN AND CONSTRUCTION. EXPERIENCE IN PRACTICALLY ALL STRUCTURAL SYSTEMS - SUSPENSION, CABLE-STAYED, STRESS-RIBBON ARCH, CANTILEVER AND TECHNOLOGIES – SPAN BY SPAN AND CANTILEVER ERECTION, LAUNCHING AND LIFTING OF STEEL OR CONCRETE STRUCTURES. EXPERIENCE WITH ELASTIC AND PLASTIC DESIGN OF BRIDGES BUILT IN SEVERE SEISMIC AREAS OF CALIFORNIA, OREGON AND TAIWAN.

PREDICTED TOPIC OF KEY NOTE: VIADUCTS WITH PROGRESSIVELY ERECTED DECKS

TWO TYPES OF BRIDGES WITH PROGRESSIVELY ERECTED DECKS WILL BE DESCRIBED IN TERMS OF THE ARCHITECTURAL AND STRUCTURAL SOLUTION AND TECHNOLOGY OF THEIR ERECTION. THE FIRST TYPE IS FORMED BY A CONCRETE SPINE BOX GIRDER THAT IS ADDITIONALLY WIDENED BY PRECAST STRUTS AND CAST-IN-PLACE OVERHANGS. THE DECKS ARE CAST IN FORMWORKS THAT WERE SUSPENDED ON OVERHANG MOVABLE SCAFFOLDING WITH SO-CALLED ORGANIC PRESTRESSING. THE DECK IS POST-TENSIONED BOTH BY INTERNAL AND EXTERNAL TENDONS. THE BRIDGES HAVE SPANS FROM 42 TO 69 M; THEIR WIDTH IS FROM 25 TO 31 M.  
THE SECOND TYPE IS FORMED BY A STEEL TROUGH THAT IS COMPOSITE WITH A CONCRETE DECK SLAB SUPPORTED BY STEEL STRUTS. THE DECK SLAB IS CAST IN A FORMWORK FORMED BY PRECAST MEMBERS. THE STEEL SECTIONS ARE INCREMENTALLY ASSEMBLED BEYOND THE ABUTMENTS AND CONSEQUENTLY LAUNCHED INTO THEIR DESIGN POSITION. AFTER THAT THE DECK SLAB IS PROGRESSIVELY ERECTED. THE BRIDGES HAVE SPANS FROM 45 TO 66 M; THEIR WIDTH IS FROM 25 M.  
THE ARRANGEMENT OF THE BRIDGES WAS DEVELOPED ON THE BASIS OF DETAILED STATIC AND DYNAMIC ANALYSES. DURING THE CONSTRUCTION THE STRAIN GAUGES WERE PLACED IN CRITICAL SECTIONS AND THE STRUCTURES WERE CAREFULLY MONITORED BOTH DURING THE ERECTION AND SERVICE.