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From page 107... ... 107 Protocols for Load Rating Bridges for Implements of Husbandry Introduction The increase of implements of husbandry (IoH) on public roads in both weight and number of trips is not uniform in all states. Read the entire page →
From page 108... ... 108 Proposed AASHTO Load Rating Provisions for Implements of Husbandry IoH renters, IoH users, farmers, IoH manufacturers, state and local bridge owners, state and local pavement owners, vehicle weight-enforcement agencies, legislators, the traveling public, and other truck drivers who may share roads with IoH vehicles. These parties may be affected by (1) Read the entire page →
From page 109... ... Protocols for Load Rating Bridges for Implements of Husbandry 109 the stakeholders identified in Step 1. Consider categorizing the identified IoH into tiers with respect to axle weights, axle spacings, gauge widths, traffic volumes (frequency of appearance) Read the entire page →
From page 110... ... 110 Proposed AASHTO Load Rating Provisions for Implements of Husbandry Tiers 2 and 3 are recommended to include those IoH vehicles beyond Tier 1 in weight. Tier 2 vehicles are less severe than Tier 3 but more than Tier 1, which may still require bridge- and IoH-specific load rating. Read the entire page →
From page 111... ... Protocols for Load Rating Bridges for Implements of Husbandry 111 allowed to carry all Tier 1 IoH loads. In other words, Tier 1 IoH vehicles will not be required to be checked individually for load rating each bridge. Read the entire page →
From page 112... ... 112 Proposed AASHTO Load Rating Provisions for Implements of Husbandry vehicle as the notional model. The recommended Tier 1 notional model in Figure A-1 may be considered in determining Tier 2's notional model using a multiplying factor larger than 1.0 if the former configuration (its axle loads and axle spacings) Read the entire page →
From page 113... ... Protocols for Load Rating Bridges for Implements of Husbandry 113 γDW = LRFD load factor for wearing surfaces and utilities γp = LRFD load factor for permanent loads other than dead loads = 1.0 γLL,IoH = IoH evaluation live load factor, depending on IoH tier For LLIoH, IMIoH, and γLL,IoH, NCHRP Research Report 951 for Project 12-110 provides more details for determining their values considering IoH vehicle loads. The remaining symbols in Eq.1a have been defined in current MBE. Read the entire page →
From page 114... ... 114 Proposed AASHTO Load Rating Provisions for Implements of Husbandry 20 0.796 1.285 1.410 1.562 1.104 1.054 1.005 1.005 1.005 21 0.797 1.294 1.420 1.572 1.107 1.047 0.993 0.993 0.993 22 0.798 1.302 1.428 1.582 1.109 1.043 0.981 0.981 0.981 23 0.798 1.309 1.419 1.590 1.113 1.038 0.972 0.968 0.968 24 0.798 1.315 1.404 1.596 1.114 1.034 0.962 0.952 0.952 25 0.797 1.321 1.391 1.603 1.116 1.030 0.956 0.939 0.939 26 0.796 1.324 1.379 1.610 1.118 1.027 0.948 0.926 0.921 27 0.796 1.330 1.368 1.615 1.119 1.024 0.943 0.915 0.903 28 0.794 1.334 1.359 1.619 1.109 1.021 0.937 0.905 0.889 29 0.793 1.338 1.349 1.624 1.098 1.018 0.932 0.896 0.875 30 0.792 1.319 1.341 1.627 1.088 1.016 0.927 0.889 0.863 32 0.789 1.285 1.328 1.586 1.072 1.013 0.919 0.875 0.843 34 0.785 1.258 1.316 1.541 1.058 1.006 0.913 0.863 0.826 36 0.781 1.234 1.307 1.504 1.045 0.989 0.901 0.854 0.809 38 0.777 1.214 1.298 1.472 1.035 0.973 0.886 0.837 0.793 40 0.771 1.197 1.290 1.445 1.026 0.960 0.872 0.821 0.779 42 0.754 1.183 1.284 1.422 1.018 0.949 0.860 0.807 0.767 44 0.736 1.169 1.278 1.401 1.011 0.939 0.850 0.795 0.756 46 0.722 1.161 1.276 1.388 1.008 0.932 0.843 0.786 0.749 48 0.716 1.163 1.285 1.387 1.013 0.934 0.844 0.785 0.749 50 0.710 1.165 1.250 1.385 1.017 0.936 0.845 0.785 0.749 52 0.704 1.167 1.221 1.358 1.022 0.938 0.846 0.784 0.749 54 0.699 1.169 1.195 1.323 1.026 0.939 0.847 0.783 0.749 56 0.694 1.170 1.172 1.292 1.030 0.941 0.847 0.783 0.749 58 0.689 1.171 1.153 1.266 1.033 0.942 0.848 0.782 0.749 60 0.684 1.173 1.135 1.243 1.036 0.943 0.849 0.782 0.749 70 0.701 1.247 1.132 1.211 1.110 1.003 0.901 0.826 0.793 80 0.709 1.303 1.134 1.170 1.167 1.049 0.941 0.860 0.826 90 0.710 1.345 1.135 1.144 1.209 1.083 0.971 0.885 0.851 100 0.707 1.378 1.136 1.126 1.243 1.110 0.994 0.904 0.871 120 0.694 1.426 1.136 1.102 1.292 1.149 1.028 0.933 0.899 140 0.676 1.459 1.137 1.088 1.326 1.176 1.051 0.952 0.919 160 0.657 1.483 1.137 1.078 1.352 1.195 1.069 0.966 0.933 180 0.637 1.501 1.138 1.070 1.371 1.210 1.082 0.977 0.944 200 0.617 1.516 1.138 1.065 1.386 1.222 1.092 0.986 0.952 250 0.571 1.542 1.138 1.055 1.413 1.243 1.110 1.001 0.967 300 0.530 1.559 1.138 1.050 1.432 1.257 1.122 1.011 0.977 Span, IoH/ HL93 IoH/ Type3 IoH/ Type3S2 IoH/ Type3-3 IoH /SU4 IoH /SU5 IoH /SU6 IoH /SU7 IoH /NRLft Table A-2. Ratios of maximum simple span moment of recommended IoH notional load to AASHTO HL93 and legal vehicles. Read the entire page →
From page 115... ... Protocols for Load Rating Bridges for Implements of Husbandry 115 minimizing the majority of load-rating analysis work while accommodating the majority of IoH loads desiring access to public roads in the jurisdiction. In other words, a current load rating in terms of any of these AASHTO vehicles can be converted to an IoH rating using Table A-2. Read the entire page →
From page 116... ... 116 Proposed AASHTO Load Rating Provisions for Implements of Husbandry implements of husbandry. Figures A-1a and A-1 b are typical examples of the former, and Figure A-1c is of the latter. Read the entire page →
From page 117... ... Protocols for Load Rating Bridges for Implements of Husbandry 117 The application ranges for Eqs. Read the entire page →
From page 118... ... 118 Proposed AASHTO Load Rating Provisions for Implements of Husbandry For interior longitudinal beam shear in LRFD Design Table 4.6.2.2.3a-1: = −             1 0.362 6 6 9 (15) 1 0.51 0.17 MF R Ln GW t Ss For exterior longitudinal beam shear in LRFD Design Table 4.6.2.2.3b-1: = −             1 0.284 6 6 9 (16) Read the entire page →
From page 119... ... Protocols for Load Rating Bridges for Implements of Husbandry 119 MF for Spans of Prestressed Concrete Box Beams Supporting Reinforced Concrete Deck -- Case (f) of Table 4.6.2.2.1-1 in BDS: For interior longitudinal beam moment in LRFD Design Table 4.6.2.2.2b-1: = −     1 0.198 6 (21) Read the entire page →
From page 120... ... 120 Proposed AASHTO Load Rating Provisions for Implements of Husbandry The application ranges for Eqs. Read the entire page →
From page 121... ... Protocols for Load Rating Bridges for Implements of Husbandry 121 The application ranges for Eqs. Read the entire page →
From page 122... ... 122 Proposed AASHTO Load Rating Provisions for Implements of Husbandry For interior longitudinal beam shear in LRFD Design Table 4.6.2.2.3a-1: =         1.232 9 (41) 2 0.035 0.074 MF R S GW S For exterior longitudinal beam shear in LRFD Design Table 4.6.2.2.3b-1: =         − 1.199 9 (42) Read the entire page →
From page 123... ... Protocols for Load Rating Bridges for Implements of Husbandry 123 MF for Spans of Prestressed Concrete Box Beams Supporting Reinforced Concrete Deck -- Case (f) of Table 4.6.2.2.1-1 in BDS: For interior longitudinal beam moment in LRFD Design Table 4.6.2.2.2b-1: =             0.967 (47) Read the entire page →
From page 124... ... 124 Proposed AASHTO Load Rating Provisions for Implements of Husbandry For exterior longitudinal beam shear in LRFD Design Table 4.6.2.2.3b-1: =         0.987 14 (54) 2 0.307 0.112 MF R S S GW The application ranges for Eqs. Read the entire page →
From page 125... ... Protocols for Load Rating Bridges for Implements of Husbandry 125 For LIoH, IIoH, and A2,IoH, NCHRP Research Report 951 for Project 12-110 provides more details of determining their values for IoH vehicle load. The remaining symbols in Eq. Read the entire page →
From page 126... ... 126 Proposed AASHTO Load Rating Provisions for Implements of Husbandry for LFR but is capped at 20% for IoH load, except wood components. For wood components 15 years old or older, IIoH is recommended to be also capped at 20%. Read the entire page →
From page 127... ... Protocols for Load Rating Bridges for Implements of Husbandry 127 For exterior longitudinal beam moment with DFSSHB in Article 3.23.2 of SSHB: = −         1 0.887 6 (58) 1 0.870 MF R Ln GW GW L For interior longitudinal beam shear with DFSSHB in Article 3.23.2 of SSHB: = −         1 0.509 6 14 (59) Read the entire page →
From page 128... ... 128 Proposed AASHTO Load Rating Provisions for Implements of Husbandry MF for Spans of Timber Beams Supporting Timber Deck in Article 3.23.2 of SSHB: For interior longitudinal beam moment with DFSSHB in Article 3.23.2 of SSHB: = −     1 0.340 6 (65) 1MF R Ln GW For exterior longitudinal beam moment with DFSSHB in Article 3.23.2 of SSHB: = −     1 0.376 6 (66) Read the entire page →
From page 129... ... Protocols for Load Rating Bridges for Implements of Husbandry 129 For exterior longitudinal beam shear with DFSSHB in Article 3.23.2 of SSHB: = −         1 0.526 6 12 (72) 1 0.34 MF R Ln GW S The application ranges for Eqs. Read the entire page →
From page 130... ... 130 Proposed AASHTO Load Rating Provisions for Implements of Husbandry For exterior longitudinal beam moment with DFSSHB in Article 3.23.2 of SSHB: = −     1 0.238 6 (78) 1MF R Ln GW For interior longitudinal beam shear with DFSSHB in Article 3.23.2 of SSHB: = −             1 3.097 6 6 (79) Read the entire page →
From page 131... ... Protocols for Load Rating Bridges for Implements of Husbandry 131 For exterior longitudinal beam moment with DFSSHB in Article 3.23.2 of SSHB: =     −     +     +      1.015 6 0.233 0.111 0.018 (84) 2 0.228 MF R GW S L GW L For interior longitudinal beam shear with DFSSHB in Article 3.23.2 of SSHB: =             1.035 6 (85) Read the entire page →
From page 132... ... 132 Proposed AASHTO Load Rating Provisions for Implements of Husbandry The application ranges for Eqs. Read the entire page →
From page 133... ... Protocols for Load Rating Bridges for Implements of Husbandry 133 For interior longitudinal beam shear with DFSSHB in Article 3.23.2 of SSHB: =             3.013 1 (97) 2 0.239 0.662 0.597 MF R S GW L S L For exterior longitudinal beam shear with DFSSHB in Article 3.23.2 of SSHB: =         1.297 6 (98) Read the entire page →
From page 134... ... 134 Proposed AASHTO Load Rating Provisions for Implements of Husbandry MF for Spans of Reinforced Concrete T-Beams in Article 3.23.2 of SSHB: For interior longitudinal beam moment with DFSSHB in Article 3.23.2 of SSHB: =             0.975 1 (103) 2 0.193 0.038 0.111 MF R L GW L S L For exterior longitudinal beam moment with DFSSHB in Article 3.23.2 of SSHB: =         0.968 (104) Read the entire page →
From page 135... ... Protocols for Load Rating Bridges for Implements of Husbandry 135 As a simplified example, consider a 48-ft simple bridge span, with an LRFR rating factor of 0.94 for its interior beams as primary members, referring to the AASHTO legal load, for which Type3 controls span moment for rating. Use IM = 20% (instead of 33% for other highway loads) Read the entire page →
From page 136... ... 136 Proposed AASHTO Load Rating Provisions for Implements of Husbandry Consider communicating the load-rating/permitting program design and impact study results with the identified stakeholders. Receive and study their comments and feedback. Read the entire page →

From page 107...

... 107 Protocols for Load Rating Bridges for Implements of Husbandry Introduction The increase of implements of husbandry (IoH) on public roads in both weight and number of trips is not uniform in all states.