Page 83 - Bridge and Highway Structure Rehabilitation and Repair

58 SECTION 1 ADMINISTRATIVE ISSUES

2.3.6 A Survey of Common Structural Deficiencies for Diagnostic Design
1. Condition evaluation: Documents required for preliminary assessment of the structure’s
condition include:
• In-depth inspection report
• FHWA Recording and Coding Guide for the structure inventory. The old SI&A sheet
codes for condition evaluation or bridge closure have now been replaced by a PONTIS
data sheet.
• Rehabilitation report
• Suffi ciency rating
• Underwater inspection report
• Scour rating
• Seismic rating.

2.3.7 Investigate Structural Defi ciencies

1. It is important to investigate internal structural deficiencies in the structure. Structural de-

ficiencies include one or more of the following:
• Lack of redundancy in the structural system: Figure 2.14 shows a high degree of redun-
dancy in a modern continuous bridge.
• Poor condition of superstructure and deck
• Poor condition of substructure
• Low structural capacities
• Bearings malfunction
• Corrosion
• Fatigue and fracture of beam connections.
2. Substandard geometry: Factors to consider in improving substandard geometry are:
• Lane and shoulder width
• Maximum profi le grade
• Minimum horizontal radius
• Super-elevation rate and cross slope
• Stopping sight distance and K value
• Clearance—vehicular/navigational
• Level of service and design speed
• Substandard deck geometry

Figure 2.14 The author’s design of a two-span precast highly redundant bridge.
(U.S. Route 50 in southern N.J.)