Page 28 - Bridge and Highway Structure Rehabilitation and Repair

CHAPTER 1 OVERVIEW OF BRIDGE ENGINEERING 3

Table 1.1 List of topics addressed in each chapter of this book.
S. No. Some of the Topics Addressed Chapter Number
1 Overview of Bridge Engineering 1
2 Diagnostic Design and Selective Reconstruction 2
3 Bridge Failure Studies and Safety Engineering 3
4 An Analytical Approach to Fracture and Failure 4
5 Load and Resistance Factor Rating and Redesign 5
6 Applications of LRFD and LRFR Methods 6
7 Bridge Widening and Deck Replacement Strategy 7
8 Inspection, Rating, and Health Monitoring Techniques 8
9 Conventional Repair Methods 9
10 Concrete Repair Methods 10
11 Advanced Repair Methods 11
12 Bridge Protection of Bridges Against Flood Scour and Earthquake 12
Rehabilitation and repair topics are constantly changing and represent an ongoing process. A list of publications is placed at
the end of each chapter for reference purposes.

The influence of physical location is of paramount importance:
1. Overland bridges may be described as those:
• Located over intersections, with alignment perpendicular to lower level roadway
• Located over intersections, with alignment skew to lower level roadway: In the U.S., the
majority of bridges have skew geometry in plan even though urban planning of roads is
east-west and north-south.
• Elevated bridges in valleys and gorges, over 30 feet in height
• Located over railroads perpendicular to multiple railway tracks
• Located over railroads skew to multiple railway tracks
• Ramps connecting lower level roadways to higher level roadways
• Flyovers, cloverleaf, and spaghetti intersections
• Third level overpass over an existing bridge.
2. Bridges over waterways include the following:
• Bridges over small rivers
• Bridges over wide rivers
• Elevated bridges over non-tidal rivers
• Elevated bridges over tidal rivers
• Coastal bridges connecting adjacent islands
• Floating bridges over wide rivers.
They have the following issues:
• Underwater construction for footings of abutments and piers—Waterway bridges have
deep foundations. They are diffi cult and more expensive to construct and maintain than
land bridges. Neither underwater inspections nor over-water inspections are easy compared
to land bridges.
• Flood frequency, water levels, overtopping of water
• Foundation erosion
• Aggradation and degradation.