Alcácer do Sal Bridge – rehabilitation and strengthening

An existing highway overpass located on a major motorway in Europe is examined on account of extensive longitudinal cracking on the lower face and sides of the deck, and signs of sustained damage in the piers. Material analysis reports have validated the existence of ASR activity in fine aggregates. The deck comprises a well reinforced hollow-core prestressed system, however longitudinal cracks penetrate to the interior of the hollow cores. The extent of damage is heavy considering that the laboratory values for free ASR expansion are below the threshold limits, suggesting that there may be underlying structural causes related to the response of the deck under traffic. Objective of the study is to interpret the reported damage, reproduce computationally the mechanics that led to the observed crack pattern and assess the residual structural capacity of the bridge. Detailed nonlinear finite element analysis is conducted to evaluate the structure and study the synergistic effects of structural demands, along with time-dependent phenomena and chemically induced expansion. The paper presents the numerical modeling and mechanistic evaluation of the findings through sensitivity analysis of various scenarios considered to reproduce the state of damage and to assess the effectiveness of various retrofitting strategies considered for bridge rehabilitation.

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Urban Infrastructure: Design and Preservation - Brooklyn Bridge Rehabilitation Program

IABSE Congress, New York, New York 2019: The Evolving Metropolis ◽

10.2749/newyork.2019.2753 ◽

2019 ◽

Author(s):

Robert Collyer ◽

Hasan Ahmed ◽

Raj Navalurkar ◽

Dawn Harrison

Keyword(s):

New York ◽

Rehabilitation Program ◽

Accelerated Bridge Construction ◽

Repair Work ◽

User Costs ◽

Bridge Rehabilitation ◽

Construction Techniques ◽

Bridge Structures ◽

High Level ◽

Brooklyn Bridge

The Brooklyn Bridge is a National Historic Landmark and a New York City Landmark that has been in use for over 137 years. This is one of the most pictured bridge structures in the world, while being used as a critical and vital part of the infrastructure carrying over 105,000 vehicles per day. This paper addresses the engineering challenges/solutions related to the most current rehabilitation work being performed.Contract 6 (2009 to 2017) represents a $650 million investment into the bridge to maintain it in a State of Good Repair. Work included deck replacement using accelerated bridge construction techniques and complete painting and steel repairs of the main span. A high-level traffic study and traffic simulations were developed to evaluate differing closure scenarios and their impacts on user costs and the traveling public.Contract 6A (2017 to 2019) represents a $25 million investment in maintaining the historic and aesthetic integrity of the Brooklyn Bridge structures. Approximately, 30,000 SF of granite stone cladding will be replaced under this contract.Contract 7 represents a $300 million investment that will address the rehabilitation of the historic arches on both sides of the main span and strengthening of the Towers. Construction is expected to begin in 2019.Contract 8 represents a $250 million investment. It is in the planning phase and will address a new promenade enhancement (widening) over the Brooklyn Bridge.This paper discusses how these engineering challenges were faced and resolved.

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Bridge rehabilitation and retrofit

Modern Techniques in Bridge Engineering ◽

10.1201/b11340-17 ◽

2011 ◽

pp. 169-169

Keyword(s):

Bridge Rehabilitation

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Fixed Ceramometallic Prostheses Over Anterior and Transzygomatic Implants by Using the Sinus Slot Technique—Report of a Case

Journal of Oral Implantology ◽

10.1563/777.1 ◽

2006 ◽

Vol 32 (1) ◽

pp. 38-40 ◽

Cited By ~ 1

Author(s):

Miguel Peñarrocha-Diago ◽

A. Boronat ◽

R. Cervera ◽

B. Garcia

Keyword(s):

Success Rate ◽

Good Option ◽

High Success Rate ◽

Zygomatic Bone ◽

Bridge Rehabilitation ◽

Implant Placement ◽

Window Technique ◽

Upper Jaw ◽

Maxillary Atrophy

Abstract Atrophy of the upper jaw poses problems for fixed rehabilitation of implants. Of the different management possibilities that have been developed, transzygomatic implant placement is a good option and affords a high success rate. These implants are positioned in zygomatic bone by using 2 possible techniques. We present a 48-year-old woman with severe posterior maxillary atrophy in which the canine and frontozygomatic prominence were used to place 6 anterior and 2 transzygomatic implants by using the sinus slot technique for fixed bridge rehabilitation. The advantages of the sinus slot technique over the sinus window technique are discussed.

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