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From page 16... ... 16 This section summarizes the ﬁndings of the ﬁnal analysis runs for the 1,500 bridges selected for this research. 3.1 Summary of Bridge Rating Analysis The work presented herein involved the analysis and rating of the superstructure elements in 1,500 bridges (3,043 girders) Read the entire page →
From page 17... ... if necessary and can process multiple databases at a time. The output of the software is a 138-column comma-delimited file with 4 lines of data produced for each bridge girder as follows: • Moment-Inventory • Moment-Operating • Shear-Inventory • Shear-Operating The final format for the comma-delimited file is shown in Appendix R Read the entire page →
From page 18... ... as closely as possible. During the analysis process, bridges were discarded if the process required hand calculations to provide missing LRFR input. Read the entire page →
From page 19... ... 19 Bridge Material/ Span Configuration Total # Girders Percent % Prestressed multispan 238 7.82 Prestressed simple span 847 27.83 Reinforced concrete multispan 105 3.45 Reinforced concreted simple span 394 12.95 Steel multispan 418 13.74 Steel simple span 1,041 34.21 Total 3,043 100.00 Figure 20. Bridge material/span configuration (final 12-78 breakdown) Read the entire page →
From page 20... ... for all graphs except where all different ADTTs are presented to show the effect of the ADTT. In performing the analysis, the BRASS/Virtis input ﬁles provided by several states were analyzed without any revisions, except those necessary for the LRFR rating to be completed, as they were thought to represent a cross-section of the existing bridge population. Read the entire page →
From page 21... ... 21 Y %tnecrePsredriG#latoTtliuBrae 97.0421191 Read the entire page →
From page 22... ... 22 Vehicle GVW (kips) Length (ft) Read the entire page →
From page 23... ... 23 Inventory Operating Posting Permit Routine Permit Vehicles DE-07 FL-04 NC-21 NM-04 TX-04 Special or Limited Crossing Permit Vehicles IL-01 OR-06 WA-02 Table 8. Use of rating vehicles. Read the entire page →
From page 24... ... 3.2.1. Raw Data The raw data is obtained from RIO for each set of databases. Read the entire page →
From page 25... ... The mean total load is calculated by adding the mean live load plus impact load, the mean non-composite and composite dead loads, and the mean wearing surface dead load. Equation 2 shows the mean total load equation; μDC1 is taken as the mean due to girder self-weight and μslab is taken as mean due to all other dead loads except for the wearing surface. Read the entire page →
From page 26... ... 26 Span (ft) 1 day 4 days 2 weeks 1 month 2 months 6 months 1 year 5 years 50 years 75 years 10 0.73 0.83 0.85 0.89 0.93 0.98 1.04 1.11 1.25 1.25 20 0.75 0.80 0.82 0.85 0.89 0.92 0.96 1.02 1.10 1.10 30 0.79 0.85 0.87 0.90 0.93 0.96 1.00 1.04 1.13 1.13 40 0.84 0.89 0.91 0.93 0.96 0.99 1.01 1.05 1.11 1.11 50 0.83 0.88 0.90 0.92 0.96 0.98 1.01 1.04 1.10 1.10 60 0.84 0.89 0.90 0.94 0.96 0.98 1.01 1.04 1.10 1.10 70 0.85 0.88 0.90 0.93 0.96 0.98 1.00 1.04 1.09 1.09 80 0.85 0.88 0.90 0.93 0.95 0.97 1.00 1.04 1.10 1.10 90 0.85 0.89 0.90 0.92 0.95 0.97 1.00 1.04 1.09 1.09 100 0.85 0.88 0.90 0.92 0.94 0.96 1.00 1.03 1.09 1.09 110 0.85 0.88 0.89 0.92 0.94 0.96 0.99 1.03 1.09 1.09 120 0.84 0.88 0.89 0.91 0.93 0.96 0.98 1.02 1.08 1.08 130 0.84 0.87 0.88 0.91 0.92 0.94 0.97 1.00 1.06 1.06 140 0.82 0.85 0.86 0.89 0.90 0.92 0.94 0.98 1.03 1.03 150 0.82 0.85 0.86 0.88 0.89 0.91 0.94 0.97 1.03 1.03 160 0.82 0.85 0.86 0.89 0.90 0.92 0.94 0.98 1.03 1.03 170 0.82 0.85 0.86 0.89 0.91 0.93 0.95 0.98 1.04 1.04 180 0.82 0.85 0.86 0.88 0.90 0.92 0.94 0.98 1.04 1.04 190 0.81 0.84 0.85 0.88 0.90 0.92 0.94 0.98 1.03 1.03 200 0.80 0.83 0.85 0.88 0.90 0.91 0.94 0.97 1.03 1.03 Mean Maximum Moments for Simple Spans Due to Multiple Trucks in One Lane (Divided by Corresponding HL-93 Moment) Read the entire page →
From page 27... ... • Routine Permit Vehicles -- two or more lanes loaded • Special or Limited Crossing Permit Vehicles -- single lane loaded without multiple presence factor 3.3 Rating Factor Comparison Spreadsheet This spreadsheet is used to compile the bridge geometric characteristics, dead load moments and shears, and critical moment and shear locations for each girder. Additionally, for each live load (Design Vehicle, eight permit loads, and three legal loads) Read the entire page →
From page 28... ... • Skew Angle • Tributary width (for interior girders this is equal to the average girder spacing and for exterior girders this is equal to the overhang width plus one-half the spacing between the exterior girder and ﬁrst interior girder) Scatter plots were created in an effort to observe trends within the data and how the results are affected by these different criteria: • Ratio of DC1 (unfactored dead loads applied to noncomposite cross-section) Read the entire page →
From page 29... ... for individual bridges. In other cases there was a general trend of a reduction in the rating factors. Read the entire page →
From page 30... ... of the rating factor equation being similar. This indicates that the factored live loads are likely causing most girders to have lower ratings for LRFR than for LFR, in addition to the new rating criteria discussed below. Read the entire page →
From page 31... ... – Bridges with small girder spacing and thick decks. Such arrangement produces signiﬁcantly different live load distribution factors for the two rating methods. Read the entire page →
From page 32... ... This check was not typically performed in the LFR rating. Figure 33 shows that ratings are generally lower when the capacity of the bearing stiffener was included in determining the controlling rating factor. Read the entire page →
From page 33... ... This Report ID returns the rating of the stress in the longitudinal reinforcement required by Article 5.8.3.5 of the AASHTO LRFD. Figure 34 shows that ignoring the longitudinal steel rating when determining the controlling rating leads to increased ratings for many girders. Read the entire page →
From page 34... ... this criterion is shown in Figure 36. The LRFR rating when the shear friction is ignored is generally higher than when it is included. Read the entire page →
From page 35... ... 35 ShearMoment Type 3 In te rio r C om po sit e (43 2 g ird ers ) Read the entire page →
From page 36... ... 36 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 ShearMoment Type 3-3 In te rio r C om po sit e (43 2 g ird ers ) Read the entire page →
From page 37... ... 37 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 ShearMoment Type 3S2 In te rio r C om po sit e (43 2 g ird ers ) Read the entire page →
From page 38... ... with higher ADTTs having a lower percentage of girders with ratings above 1.0. 3.4.2 Routine Permit Vehicles The results for the ﬁve vehicles treated as routine permits are shown in this section. Read the entire page →
From page 39... ... 39 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT 100 ADTT = 1000 ADTT 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT 100 ADTT = 1000 ADTT 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT 100 ADTT = 1000 ADTT 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT 100 ADTT = 1000 ADTT 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT 100 ADTT = 1000 ADTT 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT 100 ADTT = 1000 ADTT 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT 100 ADTT = 1000 ADTT 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT 100 ADTT = 1000 ADTT 5000 ShearMoment DE-07 In te rio r C om po sit e (43 2 g ird ers ) Read the entire page →
From page 40... ... 40 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 ShearMoment FL-04 In te rio r C om po sit e (43 2 g ird ers ) Read the entire page →
From page 41... ... 41 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 - 0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 ShearMoment NC-21 In te rio r C om po sit e (43 2 g ird ers ) Read the entire page →
From page 42... ... 42 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 ShearMoment NM-04 In te rio r C om po sit e (43 2 g ird ers ) Read the entire page →
From page 43... ... 43 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR ADTT ≤ 100 ADTT = 1000 ADTT ≥ 5000 ShearMoment TX-04 In te rio r C om po sit e (43 2 g ird ers ) Read the entire page →
From page 44... ... 44 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 P er ce n ta ge o f G ir de rs Rating Factor LFR Single Escorted Single ADTT ≤ 100 Single ADTT = 1000 Single ADTT ≥ 5000 Multiple ADTT ≤ 100 Multiple ADTT = 1000 Multiple ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR Single Escorted Single ADTT ≤ 100 Single ADTT = 1000 Single ADTT ≥ 5000 Multiple ADTT ≤ 100 Multiple ADTT = 1000 Multiple ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 P er ce n ta ge o f G ir d er s Rating Factor LFR Single Escorted Single ADTT ≤ 100 Single ADTT = 1000 Single ADTT ≥ 5000 Multiple ADTT ≤ 100 Multiple ADTT = 1000 Multiple ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR Single Escorted Single ADTT ≤ 100 Single ADTT = 1000 Single ADTT ≥ 5000 Multiple ADTT ≤ 100 Multiple ADTT = 1000 Multiple ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 P er ce nt ag e of G ir d er s Rating Factor LFR Single Escorted Single ADTT ≤ 100 Single ADTT = 1000 Single ADTT ≥ 5000 Multiple ADTT ≤ 100 Multiple ADTT = 1000 Multiple ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR Single Escorted Single ADTT ≤ 100 Single ADTT = 1000 Single ADTT ≥ 5000 Multiple ADTT ≤ 100 Multiple ADTT = 1000 Multiple ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 P er ce n ta ge o f G ir de rs Rating Factor LFR Single Escorted Single ADTT ≤ 100 Single ADTT = 1000 Single ADTT ≥ 5000 Multiple ADTT ≤ 100 Multiple ADTT = 1000 Multiple ADTT ≥ 5000 0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00% 100.00% > 1.0 0.9 -1.0 0.8 -0.9 0.7 -0.8 0.6 -0.7 0.5 -0.6 <0.5 Pe rc en ta ge o f G ird er s Rating Factor LFR Single Escorted Single ADTT ≤ 100 Single ADTT = 1000 Single ADTT ≥ 5000 Multiple ADTT ≤ 100 Multiple ADTT = 1000 Multiple ADTT ≥ 5000 ShearMoment IL-01 In te rio r C om po sit e (43 2 g ird ers ) Read the entire page →
From page 45... ... 45 ShearMoment OR-06 In te rio r C om po sit e (43 2 g ird ers ) Read the entire page →
From page 46... ... 46 ShearMoment WA-02 In te rio r C om po sit e (43 2 g ird ers ) Read the entire page →
From page 47... ... As expected, as the ADTT increases and the associated load factor increases, the number of girders that will pass rating decreases. The permit type and ADTT affect ﬂexural ratings more than they affect shear ratings. Read the entire page →
From page 48... ... Seventy percent of the girders with LRFR ratings less than 1.0 also have LFR ratings less than 1.0. For shear in simple span steel girders, 117 of 1,037 girders have LRFR shear ratings less than 1.0 and no girders have LFR shear ratings less than 1.0. Read the entire page →
From page 49... ... for LFR ratings less than 1.0 in tabular and graphical format for the design vehicle and continuous span steel girder bridges. Both LFR and LRFR are shown so a comparison can be made as to which method will produce lower ratings. Read the entire page →
From page 50... ... 3.6.4 Simple Span Prestressed Box Girder Bridges Table 32 and Figure 40 show the distribution of rating factor ratio for girders with LRFR ratings less than 1.0 and also for LFR ratings less than 1.0 in tabular and graphical format for the design vehicle and simple span prestressed box girder bridges. Both LFR and LRFR are shown so a comparison can be made as to which method will produce lower ratings. Read the entire page →
From page 51... ... to LFR rating less than 0.8, the factored LRFR live loads are approximately 50% higher than the factored LFR live loads. The ﬂexural resistance increased by approximately 10%. Read the entire page →
From page 52... ... when switching from LFR to LRFR. Most girders have a ratio of LRFR rating to LFR rating greater than 40%. Read the entire page →
From page 53... ... 3.6.7 Continuous Span Reinforced Concrete Slab Bridges Table 35 and Figure 43 show the distribution of rating factor ratio for girders with LRFR ratings less than 1.0 and also for LFR ratings less than 1.0 in tabular and graphical format for the design vehicle and continuous reinforced concrete slab bridges. Both LFR and LRFR are shown so a comparison can be made as to which method will produce lower ratings. Read the entire page →
From page 54... ... and also for LFR ratings less than 1.0 in tabular and graphical format for the design vehicle and simple span steel I-girder bridges. Both LFR and LRFR are shown so a comparison can be made as to which method will produce lower ratings. Read the entire page →
From page 55... ... 3.7 Comparison of Reliability Index to Live Load Factors The determination of the reliability index corresponding to the live load factor needed to make the factored loads equal to the factored resistance provided insight into what level of reliability the current load factors are providing. For each vehicle, a scatter plot is created comparing the reliability index to the required live load factor for an ADTT = 1,000. Read the entire page →
From page 56... ... 5. For any girder, specifying a load factor equal to or less than the one calculated for this girder (Step 2) Read the entire page →
From page 58... ... Truck Force Effect Target β in MBE γL in MBE (ADTT = 1,000) β corresponding to current γL γL corresponding to target β Figure DE-07 Moment 2.5 1.6 3.6 1.15 Figure (a) Read the entire page →
From page 63... ... 63 -2.00 0.00 2.00 4.00 6.00 8.00 10.00 -1.00 0.00 1 -2.00 0.00 2.00 4.00 6.00 8.00 10.00 -1.00 0.00 1 (a) .00 2.00 3.00 4.00 5.00 R e lia bi lit y In de x , LRFR Live Load Factor Simple Span Steel Simple Span PS I Simple Span PS Box Simple Span RC T-Beam Simple Span RC Slab Continuous Steel Continuous RC Slabs Continuous PS I (b) Read the entire page →
From page 64... ... 64 -2.00 0.00 2.00 4.00 6.00 8.00 10.00 -1.00 0.00 1 - 2.00 0.00 2.00 4.00 6.00 8.00 10.00 -1.00 0.00 1 (a) .00 2.00 3.00 4.00 5.00 R e lia bi lit y In de x , LRFR Live Load Factor Simple Span Steel Simple Span PS I Simple Span PS Box Simple Span RC T-Beam Simple Span RC Slab Continuous Steel Continuous RC Slabs Continuous PS I (b) Read the entire page →
From page 65... ... 65 -2.00 0.00 2.00 4.00 6.00 8.00 10.00 -1.00 0.00 1 -2.00 0.00 2.00 4.00 6.00 8.00 10.00 -1.00 0.00 1 (a) .00 2.00 3.00 4.00 5.00 R e lia bi lit y In de x , LRFR Live Load Factor Simple Span Steel Simple Span PS I Simple Span PS Box Simple Span RC T-Beam Simple Span RC Slab Continuous Steel Continuous RC Slabs Continuous PS I (b) Read the entire page →
From page 66... ... 66 -2.00 0.00 2.00 4.00 6.00 8.00 10.00 -1.00 0.00 1 -2.00 0.00 2.00 4.00 6.00 8.00 10.00 -1.00 0.00 1 (a) .00 2.00 3.00 4.00 5.00 R e lia bi lit y In de x , LRFR Live Load Factor Simple Span Steel Simple Span PS I Simple Span PS Box Simple Span RC T-Beam Simple Span RC Slab Continuous Steel Continuous RC Slabs Continuous PS I (b) Read the entire page →
From page 67... ... in bold/italic typeface. The shown values were rationally determined considering the currently existing values in the MBE and the difference between the existing and proposed load factors for the same ADTT where analyses were conducted to support the proposed values. Read the entire page →
From page 68... ... 68 -2.00 0.00 2.00 4.00 6.00 8.00 10.00 -1.00 0.00 1 -2.00 0.00 2.00 4.00 6.00 8.00 10.00 -1.00 0.00 1 (a) .00 2.00 3.00 4.00 5.00 R e lia bi lit y In de x , LRFR Live Load Factor Simple Span Steel Simple Span PS I Simple Span PS Box Simple Span RC T-Beam Simple Span RC Slab Continuous Steel Continuous RC Slabs Continuous PS I (b) Read the entire page →
From page 69... ... 69 -2.00 0.00 2.00 4.00 6.00 8.00 10.00 -1.00 0.00 1 -2.00 0.00 2.00 4.00 6.00 8.00 10.00 -1.00 0.00 1 (a) .00 2.00 3.00 4.00 5.00 R e lia bi lit y In de x , LRFR Live Load Factor Simple Span Steel Simple Span PS I Simple Span PS Box Simple Span RC T-Beam Simple Span RC Slab Continuous Steel Continuous RC Slabs Continuous PS I (b) Read the entire page →
From page 70... ... 70 -2.00 0.00 2.00 4.00 6.00 8.00 10.00 -1.00 0.00 1 -2.00 0.00 2.00 4.00 6.00 8.00 10.00 -1.00 0.00 1 (a) .00 2.00 3.00 4.00 5.00 R e lia bi lit y In de x , LRFR Live Load Factor Simple Span Steel Simple Span PS I Simple Span PS Box Simple Span RC T-Beam Simple Span RC Slab Continuous Steel Continuous RC Slabs Continuous PS I (b) Read the entire page →
From page 71... ... 71 Vehicle Moment Shear Critical Routine Permit Vehicles DE-07 β = 2.5 1.15 1.15 1.15 FL-04 β = 2.5 1.15 1.15 1.15 NC-21 β = 2.5 1.15 1.15 1.15 NM-04 β = 2.5 1.15 1.25 1.25 TX-04 β = 2.5 1.15 1.15 1.15 Special or Limited Crossing Permits IL-01 β = 2.5 1.10 1.15 1.15 β = 3.5 1.50 1.45 1.50 OR-06 β = 2.5 1.05 1.15 1.10 β = 3.5 1.50 1.45 1.50 WA-02 β = 2.5 1.05 1.10 1.10 β = 3.5 1.35 1.45 1.45 Legal Loads Type 3 β = 2.5 1.15 1.30 1.30 Type 3S2 1.10 1.10 1.10 Type 3-3 1.15 1.10 1.15 Table 40. Proposed live load factors for ADTT = 1,000. Read the entire page →
From page 72... ... Column 3 -- Vehicle type (design, legal, routine permit, special permit) Column 4 -- Vehicle Name Column 5 -- Load Effect (Moment/Shear) Read the entire page →
From page 73... ... 73 Permit Type Frequency Loading Condition DF ADTT (one direction) Load Factor Routine or Annual Unlimited Crossings Mix with traffic (other vehicles may be on the bridge) Read the entire page →
From page 74... ... in the study. Column 9 shows the number of girders with shear ratings less than 1.0 when the bearing stiffener rating is ignored. Read the entire page →
From page 75... ... tion rating between the girder and composite slab. Column 12 contains the number of girders with LRFR ratings less than 1.0 when the proposed load factors are utilized and no rating criteria are ignored; column 13 is the same as Column 6 and contains the number of girders with LFR ratings less than 1.0. Read the entire page →
From page 76... ... than 1.0. Column 13 is the percent change between Column 11 and Column 12. Read the entire page →
From page 77... ... Generally, Tables 50 through 57 indicate that a signiﬁcant percentage of girders that passed rating under the LFR and produced rating factors below 1.0 for the LRFR were controlled by criteria that were not checked under the LFR method of rating. Some of these criteria are not known to have caused problems in the past. Read the entire page →
From page 78... ... shown in Section 3.6) are presented in Appendix M Read the entire page →
From page 79... ... ranged from 0.62 to 0.64 and using the proposed live load factors has increased to 0.70–0.71. For shear, the average ratio increased from 0.72–0.81 to 0.86–1.0 for all vehicle types. Read the entire page →
From page 80... ... 80 Total % Change Ignoring 85004 % Change 85107 (M) Read the entire page →
From page 81... ... 81 Moment (LRFR/LFR) Shear (LRFR/LFR) Read the entire page →
From page 82... ... 3.9.9.6 Continuous Span Steel Girder Bridges Table 63 shows the average of the ratio between the LRFR rating and the LFR rating for the existing live load factors in the MBE and the proposed live load factors. The proposed live load factors result in an increase in the average ratio for moment from 0.81–0.88 to 1.02–1.12 for the AASHTO legal and routine permit vehicles. Read the entire page →
From page 83... ... 83 Moment (LRFR/LFR) Shear (LRFR/LFR) Read the entire page →

From page 16...

... 16 This section summarizes the ﬁndings of the ﬁnal analysis runs for the 1,500 bridges selected for this research. 3.1 Summary of Bridge Rating Analysis The work presented herein involved the analysis and rating of the superstructure elements in 1,500 bridges (3,043 girders)