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From page 25... ... 25 CHAPTER 3 CONCEPT OF RECOMMENDED METHODOLOGY FOR ESTIMATING BRIDGE NETWORK COSTS DUE TO TRUCK WEIGHT LIMIT CHANGES This chapter presents the concept of the recommended methodology, whose procedure is given in Appendix A Before applying this methodology to a specific scenario of truck weight limit change, a planning period, PP, in years needs to be determined by the user. Read the entire page →
From page 26... ... significant implication on the reliability of the application result, because more detailed data generally would permit better fidelity to the analysis and therefore more accurate results. Based on the survey results discussed in Section 2.2 related to the variability of available data, two levels of data requirement are designed for the recommended methodology. Read the entire page →
From page 27... ... whose PMGVWs are determined by limits in other states. When a truck travels through several states with different truck weight limits, its PMGVW is the most restrictive PMGVW in all of the states in which it operates. Read the entire page →
From page 28... ... under the Alternative Scenario. Beyond this small range to the left, the level of weight-limit-dependence is assumed to vary linearly from c at 1 − a1 to zero at 1 − b1 being the lower boundary of the neighborhood. Read the entire page →
From page 29... ... and 350 to 375 kN (with midpoint GVWi + 1,AS equal to 362.5 kN) Read the entire page →
From page 30... ... traffic subject to adjustment. These changes should be made to the intervals surrounding the tare weight, as follows ∆TTTARE − GVW,BC = −rE/L TT ′GVWk,BC (3.2.2.9) Read the entire page →
From page 31... ... The Act significantly altered the trucking industry by allowing carriers to increase their service territories and the types of commodities they could transport. This deregulation greatly decreased the amount of empty backhaul traffic by allowing trucks to obtain loads for the backhaul portion of their trip, instead of returning to their operation base empty. Read the entire page →
From page 32... ... Formula. It should be noted that typically permit weightlimit changes might affect only a small fraction of the total truck traffic. Read the entire page →
From page 33... ... fic amount to shift away, and the CS6 trucks (with an 3S3 configuration) will receive an additional traffic amount. Read the entire page →
From page 34... ... TABLE 3.4 Normalized VMT data from Table 3.3 and summed to TWH,BC as last column (impacted truck types 3S2T and 3S2S (shift from) and CS6 (shift to) Read the entire page →
From page 35... ... addition, b1 and b2 indicate another range (i.e., b1 + b2) where there is an impact. Read the entire page →
From page 36... ... 36 TABLE 3.5 3S2T shifting calculations and results Pi,Pi+1for Pi,Pi+1for Pi,Pi+1for Pi,Pi+1for Pi,Pi+1for Pi,Pi+1for GVWAS= GVWAS= GVWAS= GVWAS= GVWAS= GVWAS= GVWk,BC TTGVWK,BC window-f TT'GVWK, GVW AS TTGVW,As81.844 87.906 93.969 100.031 106.094 112.156 TTGVWAS (column 3S2T Eq.3.2.2.1 Eq.3.2.2.2aEq.3.2.2.2bEq.3.2.2.4 Eq.3.2.2.4 Eq.3.2.2.4 Eq.3.2.2.4 Eq.3.2.2.4 Eq.3.2.2.4 of Table 3.4) Eq.3.2.2.5 Eq.3.2.2.5 Eq.3.2.2.5 Eq.3.2.2.5 Eq.3.2.2.5 Eq.3.2.2.5 2.5 0.00000 7.5 0.00000 12.5 0.00000 17.5 0.00030 22.5 0.00090 27.5 0.00241 32.5 0.01294 37.5 0.01896 -0.00230 42.5 0.02106 -0.00423 +0.000241 47.5 0.02588 -0.00383 +0.001600 52.5 0.02648 -0.00469 +0.003122 57.5 0.03611 -0.00652 +0.002455 62.5 0.03009 -0.00213 +0.002775 67.5 0.02768 0.415625 0.01151 81.844 0.00921 +0.003399 72.5 0.02227 0.95 0.02115 87.906 0.01699 +0.003908 77.5 0.02016 0.95 0.01915 93.969 0.01543 0.13125 +0.001604+ 82.5 0.02468 0.95 0.02344 100.031 0.01892 0.86875 0.00800 87.5 0.03430 0.95 0.03259 106.094 0.02636 0.91875 0.01561 92.5 0.02558 0.415625 0.01063 112.156 0.00861 0.08125 0.70625 0.01228 97.5 0.01204 0.29375 0.49375 0.01388 102.5 0.00602 0.50625 0.28125 0.01699 107.5 0.00301 0.71875 0.06875 0.01954 112.5 0.00000 0.93125 0.00802 117.5 0.00000 122.5 0.00000 127.5 0.00000 132.5 0.00000 137.5 0.00000 142.5 0.00000 147.5 0.00000 Total 0.35087 0.14218 0.09553 0.11463 GVWj,AS 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 62.5 67.5 72.5 77.5 82.5 87.5 92.5 97.5 102.5 107.5 112.5 117.5 122.5 127.5 132.5 137.5 142.5 147.5 Read the entire page →
From page 37... ... 37 TABLE 3.6 3S2S shifting calculations and results Pi,Pi+1for Pi,Pi+1for Pi,Pi+1for Pi,Pi+1for Pi,Pi+1for Pi,Pi+1for GVWAS= GVWAS= GVWAS= GVWAS= GVWAS= GVWAS= GVWk,BC TTGVWK,BC window-f TT'GVWK,BC GVW AS TTGVW,As81.844 87.906 93.969 100.031 106.094 112.156 (column 3S2S Eq.3.2.2.1 Eq.3.2.2.2aEq.3.2.2.2bEq.3.2.2.4 Eq.3.2.2.4 Eq.3.2.2.4 Eq.3.2.2.4 Eq.3.2.2.4 Eq.3.2.2.4 of Table 3.4) Eq.3.2.2.5 Eq.3.2.2.5 Eq.3.2.2.5 Eq.3.2.2.5 Eq.3.2.2.5 Eq.3.2.2.5 2.5 0.000E+00 7.5 0.000E+00 12.5 0.000E+00 17.5 4.983E-05 22.5 4.584E-04 27.5 5.182E-04 32.5 5.481E-04 37.5 4.784E-04 -3.893E-05 42.5 4.186E-04 -6.438E-05 47.5 3.488E-04 -5.870E-05 52.5 3.887E-04 -5.112E-05 57.5 4.285E-04 -3.787E-05 62.5 4.784E-04 -1.574E-05 67.5 4.684E-04 0.415625 1.947E-04 81.844 1.558E-04 72.5 3.388E-04 0.95 3.219E-04 87.906 2.586E-04 77.5 3.089E-04 0.95 2.935E-04 93.969 2.364E-04 0.13125 82.5 2.691E-04 0.95 2.556E-04 100.031 2.064E-04 0.86875 87.5 1.993E-04 0.95 1.893E-04 106.094 1.531E-04 0.91875 92.5 1.893E-04 0.415625 7.870E-05 112.156 6.375E-05 0.08125 0.70625 97.5 1.395E-04 0.29375 0.49375 102.5 2.990E-05 0.50625 0.28125 0 107.5 1.993E-05 0.71875 0.06875 112.5 2.990E-05 0.93125 117.5 0.000E+00 122.5 0.000E+00 127.5 0.000E+00 132.5 0.000E+00 137.5 0.000E+00 142.5 0.000E+00 147.5 0.000E+00 Total 0.00610901 0.001601 0.001074 TTGVWAS GVWj,AS 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 +4.091E-06 42.5 +2.708E-05 47.5 +4.751E-05 52.5 +3.759E-05 57.5 +3.427E-05 62.5 +2.951E-05 67.5 +2.289E-05 72.5 +1.187E-05 77.5 1.354E-04 82.5 2.376E-04 87.5 1.880E-04 92.5 1.713E-04 97.5 1.475E-04 102.5 1.145E-04 107.5 5.937E-05 112.5 117.5 122.5 127.5 132.5 137.5 142.5 147.5 1.289E-03 Read the entire page →
From page 38... ... 38 TABLE 3.7 Predicted TWH under alternative scenario (non-normalized) GVWj,ASSU3 SU4 CS3 CS4 3S2T 3S2S CS6 CS7 CT4 CT5 CT6 DS5 2.5 0 0 0 0 0 0 0 0 0 0 0 0 7.5 0 0 0.00807 0 0 0 0 0 0.00036 0 0 0 12.5 0 0 0.16138 2.05375 0 0 0 0 0.00188 6.6E-05 0 0 17.5 0.79797 0.04773 0.91182 1.36916 0.0003 5E-05 0.00036 0 0.00218 0.00079 0.00015 0 22.5 3.14492 0.48778 1.66225 2.79099 0.0009 0.00046 0.00057 0 0.00319 0.00066 0.00023 0.00015 27.5 3.56738 1.92241 2.62248 3.00163 0.00241 0.00052 0.0014 0 0.0037 0.00124 0.00037 0.00071 32.5 3.37962 2.18065 2.08184 3.10695 0.01294 0.00055 0.00633 5.4E-05 0.00367 0.00164 0.00068 0.00155 37.5 2.82593 2.06588 1.34755 3.26493 0.01896 0.00048 0.0055 0.00025 0.00236 0.00175 0.00076 0.00239 42.5 2.10747 0.62055 1.00865 3.31759 0.02106 0.00042 0.00529 0.00074 0.00149 0.00187 0.00095 0.00288 47.5 2.63434 0.85922 0.71009 3.26493 0.02588 0.00035 0.00345 0.00103 0.00071 0.0013 0.0007 0.00313 52.5 2.15537 1.57523 0.21787 3.10695 0.02648 0.00039 0.00254 0.00138 0.00027 0.00144 0.00073 0.00262 57.5 1.5806 1.98097 0.12911 1.63247 0.03611 0.00043 0.00179 0.0009 0.00019 0.00139 0.00069 0.00209 62.5 0.71846 2.24351 0.02421 1.0532 0.03009 0.00048 0.00184 0.00056 0.00015 0.00147 0.00072 0.00219 67.5 0.47897 2.0287 0 0.31596 0.01618 0.00027 0.00228 0.00038 6.7E-05 0.00164 0.00031 0.00132 72.5 0.0479 1.50363 0 0.36862 0.00111 1.7E-05 0.00324 0.00032 4E-05 0.00134 0.00036 0.00099 77.5 0 0.78762 0 0.10532 0.00101 1.5E-05 0.00631 0.00025 0 0.00064 0.00025 0.00051 82.5 0 0.38187 0 0.05266 0.00123 1.3E-05 0.01516 0.00016 0 0.00071 0.00012 0.00066 87.5 0 0.23867 0 0.10532 0.00172 1E-05 0.02557 0.00018 0 0.00066 0.00016 0.00025 92.5 0 0.11934 0 0 0.01495 0.00011 0.02457 0.00052 0 0.00068 4.3E-05 7.6E-05 97.5 0 0.04773 0 0 0.01204 0.00014 0.02338 0.00047 0 0.00026 6.1E-05 0.0001 102.5 0 0 0 0 0.00602 3E-05 0.02253 0.00054 0 0.00013 2.6E-05 0 107.5 0 0 0 0 0.00301 2E-05 0.02279 0.00022 0 1.7E-05 2.6E-05 0 112.5 0 0 0 0 0 3E-05 0.01005 0.00031 0 0 1.7E-05 0 117.5 0 0 0 0 0 0 0.00104 3.6E-05 0 0 3.5E-05 0 122.5 0 0 0 0 0 0 0.00039 3.6E-05 0 0 8.7E-06 0 127.5 0 0 0 0 0 0 0.00036 1.8E-05 0 0 0 0 132.5 0 0 0 0 0 0 0 0 0 0 0 0 137.5 0 0 0 0 0 0 0 0 0 0 0 0 142.5 0 0 0 0 0 0 0 0 0 0 0 0 147.5 0 0 0 0 0 0 0 0 0 0 0 0 Total Note: Traffic amount reduction = 1 - 0.976791 = 0.023209 DS6 DS7 DS8 TRP TWH,AS 0 0 0 0 0 0 0 0 0 0.0004 0 0 0 0 0.01187 1.4E-06 0 0 0 0.01785 5.6E-06 0.00022 0 0 0.04265 1.8E-05 0.00029 0 0 0.06048 4.5E-05 0.00025 0 0 0.0759 4.4E-05 0.00057 0 0 0.07567 8.7E-05 0.00051 0.00287 0 0.06978 7.7E-05 0.00073 0.0035 0 0.07435 7.9E-05 0.00089 0.00319 0 0.07164 7.9E-05 0.0007 0.00701 0 0.07523 6.3E-05 0.00073 0.00573 0 0.06214 7.5E-05 0.00092 0.00637 0 0.04248 8.5E-05 0.00067 0.0035 0 0.02029 5.6E-05 0.00114 0.00191 0 0.01611 3.5E-05 0.00092 0.00478 0 0.02575 1.7E-05 0.00105 0.00701 0 0.03817 7E-06 0.0007 0.0051 0 0.04729 4.2E-06 0.00086 0.00765 0 0.04517 1.4E-06 0.0006 0.00605 0 0.03594 2.8E-06 0.00041 0.00446 0 0.03095 0 0.00032 0.00223 0 0.01295 7E-07 0.00038 0.00223 0 0.00372 0 0.00025 0.00287 0 0.00355 0 0.00016 0.00319 0 0.00373 0 0.00022 0.00414 0 0.00436 0 0.00019 0.00223 0 0.00242 0 9.5E-05 0.00096 0 0.00105 0 0.00013 0.00478 0 0.00491 0.97679 Read the entire page →
From page 39... ... Step D Account for effects of tare weight changes. Read the entire page →
From page 40... ... this additional amount to be added to the average wheel weight. Based on WIM data provided by the Idaho Transportation Department (ITD) Read the entire page →
From page 41... ... to reach a cost estimate, such as the procedure to obtain the stress range, the repair or replacement procedure, associated unit costs, etc. When the network being analyzed is extensive including a large number of bridges, a smaller sample will be desired considering the resource constraint. Read the entire page →
From page 42... ... inspection (monitoring) is warranted, the expected repair and replacement costs are recommended below. Read the entire page →
From page 43... ... 3.3.4.2 Alternative Scenario A specific scenario of weight limit change is selected for this investigation: legalizing GVW of 431 kN (97 kips) on 6 axles. Read the entire page →
From page 44... ... 2. If most 6-axle semis have a configuration of 3S3-B, the AASHTO fatigue truck will be less valid. Read the entire page →
From page 45... ... there is that, within a jurisdiction, the variation of situation may be much smaller. This situation may make it possible to perform detailed analysis for several typical vulnerable details common within the jurisdiction. Read the entire page →
From page 46... ... truck. P/Pu is the equivalent stress ratio caused by wheel load P defined as follows: P/Pu = [Σfi(Pi /Pu) Read the entire page →
From page 47... ... 47 Figure 3.5. Finite element analysis model for Bridge 1596 in Arizona. Read the entire page →
From page 48... ... shear effect increase due to closely spaced wheels varies from 2 to 9 percent. Based on this set of analysis data, the recommended value for Ps is determined at 1.04 for Eq. Read the entire page →
From page 49... ... Here 17.95 = −1/B with B = −0.0557 taken from Eq. 3.4.1.3 based on reported physical testing results. Read the entire page →
From page 50... ... Rd is set equal to 1.35 being the same as Rs for steel fatigue. This Rs value corresponds to a reliability index β = 0.94, due to higher uncertainty observed than that in steel fatigue. Read the entire page →
From page 51... ... state agencies obtain jurisdiction specific values for these parameters, using available WIM data that include axle weights and distances. X is the residual from the average wheel weight predicted by the regression relationship 0.5 (e + f GVW) Read the entire page →
From page 52... ... impact factor plays an important role in the resulting probability of failure, using Eq. 3.4.2.7 for cost estimation. Read the entire page →
From page 53... ... extended end of deck life by concrete overlay is expected to be beyond the typical PP of 20 years. In other words, within this default PP, the need will unlikely occur for replacing an overlaid deck. Read the entire page →
From page 54... ... that have been subjected to much less salt than in the rest of the state. These bridges should also be analyzed for RC deck fatigue. Read the entire page →
From page 55... ... 55 service life subjected to rebar-corrosion due to salting only. This project has developed a model to estimate Yd as follows: (3.4.2.1b) Read the entire page →
From page 56... ... regions. They will provide data points to guide the surface's trend in Figs. Read the entire page →
From page 57... ... where W* Read the entire page →
From page 58... ... general heavy loads and higher truck traffic and therefore a lower design load is justifiable. 3.6.1 Level I Analysis At this level of data requirement and the related amount of analysis, new bridges constructed in recent years are used to estimate the costs that are expected if the considered Alternative Scenario is implemented. Read the entire page →
From page 59... ... growth that result in more new bridges to be built. This may be covered at the network level by a growth factor to the total costs obtained. Read the entire page →

From page 25...

... 25 CHAPTER 3 CONCEPT OF RECOMMENDED METHODOLOGY FOR ESTIMATING BRIDGE NETWORK COSTS DUE TO TRUCK WEIGHT LIMIT CHANGES This chapter presents the concept of the recommended methodology, whose procedure is given in Appendix A Before applying this methodology to a specific scenario of truck weight limit change, a planning period, PP, in years needs to be determined by the user.