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From page 21... ... 21 C h a p t e r 3 The details of technical approaches and results are provided in this section. Major parameters related to bridge types, load effects, and forces associated with rail–train–structure interaction are studied. Read the entire page →
From page 22... ... 22 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads using a conventional laboratory data acquisition system. At typical loads of 12 kips and 14 kips in the continuous rail test, the strain reading of these two systems was almost identical. Read the entire page →
From page 23... ... research program 23 Santa Fe Bridge. The Santa Fe Bridge is a 2-span multicell prestressed concrete box girder bridge, as shown in Figure 3.9(a) Read the entire page →
From page 24... ... 24 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads converted to the wheel load of the trains using the formulas developed in the laboratory test, which were also calibrated with the stationary light rail trains as mentioned in Section 3.1.2. When interpreting the train load, the temperature effect discussed in Section 3.1.3.2 was compensated. Read the entire page →
From page 25... ... research program 25 (3.1) 1 LDF m I I i i i ii n∑= ε ε = where m = the number of loaded tracks; Ii and ei = the moment of inertia of the cross section and the strain of the ith girder, respectively; and n = the total number of girders in the superstructure. Read the entire page →
From page 26... ... 26 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads was exploited. Using the IBIS system, the vibration and displacement data of all five bridges were collected and analyzed (to be discussed in a modeling section) Read the entire page →
From page 27... ... research program 27 3.2.2 Model Validation Against Field Test Data 3.2.2.1 Strain Response and Live Load Distribution Figure 3.24 reveals the strain response of the individual bridges. Two-track loaded cases for the Santa Fe and the County Line Bridges were not observed on site (Figures 3.24(c) Read the entire page →
From page 28... ... 28 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads downward and upward displacements, respectively. It should be noted that the direction of train operation affected the positive and negative displacements of the monitored span in continuous bridge systems (i.e., downward to upward deflections or upward to downward deflections with time in Figure 3.25) Read the entire page →
From page 29... ... research program 29 3.2.3 Design of Benchmark Bridges Five types of benchmark bridges were designed for a numerical parametric study (Table 3.7) : steel plate girder, prestressed concrete multicell box, reinforced concrete T-beam, prestressed concrete I-girder, and steel box girder bridges subjected to light rail trains (the RTD light rail train load discussed in Section 3.1) Read the entire page →
From page 30... ... 30 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads examined the DLA of the benchmark bridges subjected to the light rail trains running at a design speed of 60 mph. One-track-loaded and two-track-loaded cases were modeled. Read the entire page →
From page 31... ... research program 31 (3.3) 2 e dV gR = where d = the horizontal projection of the track contact point distance (d = 4.7 ft for light rail trains) Read the entire page →
From page 32... ... 32 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads A blend of deterministic and probabilistic approaches was used in the development of the standard live load model for light rail train gravity loadings. This dual-faceted methodology maximizes the utility and information garnered from each approach (i.e., rapid development of a base or benchmark load model using the results from deterministic finite element models and then subsequently addressing uncertainty by conducting probability analyses with the data produced by the models) Read the entire page →
From page 33... ... research program 33 effects. It is important to note that the effect of small differences in the existing live load models should be insignificant with regard to the behavior of the bridges and, as such, the number of the numerical models employed was not unrealistically large. Read the entire page →
From page 34... ... 34 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads presented are maximum values along bridge spans, which would represent the behavior (or maximum load effects) of the light rail bridges. Read the entire page →
From page 35... ... research program 35 shortest span reinforced concrete bridges (L = 30 ft) demonstrated a higher load. Read the entire page →
From page 36... ... 36 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads spacing. The trend found is that the magnitude of the equivalent concentrated load P gradually rose with an increase in axle spacing. Read the entire page →
From page 37... ... research program 37 3.3.3.4 Assessment of the Candidate Standard Live Load Models All simply supported benchmark bridges (Table 3.7) were loaded with the four candidate live load models developed in Section 3.3.3.3 and corresponding maximum static bending moments were predicted, as shown in Figure 3.61, based on moving load simulation technique. Read the entire page →
From page 38... ... 38 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads 3.3.3.6 Evaluation of Proposed Load Model Using Load-Enveloping Method The proposed standard live load model (Figure 3.65) was evaluated using 33 light rail trains operated in the United States (29 trains) Read the entire page →
From page 39... ... research program 39 generating a uniform bias. NCHRP Report 368 justifies use of the probability-based method by stating that "a considerable degree of uncertainty is caused by unpredictability of the future trends with regard to configuration of axles and weights." After many trials, load effects caused by a combination of HS20 and a lane load of 0.64 k/ft were found to be comparable to the 75-year anticipated maximum load effects with a relatively consistent bias for highway bridges (NCHRP Report 368) Read the entire page →
From page 40... ... 40 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads The approach taken in this research program is basically the same as that of NCHRP Report 368, in that bridge responses were predicted by finite element models (validated against in situ light rail bridge responses) using the representative light rail train loads, and corresponding results were extrapolated up to 75 years using probability theory. Read the entire page →
From page 41... ... research program 41 concrete girder bridges exhibited the least deflections because of their substantial flexural rigidity and short span length, respectively, regardless of structural determinacy (i.e., simply supported or multiple spans) Read the entire page →
From page 42... ... 42 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads and interior girders. The AASHTO LRFD BDS method exhibited better prediction compared with the lever rule; nonetheless, it still demonstrated discrepancy. Read the entire page →
From page 43... ... research program 43 and 3+2+3 loading cases (Figure 3.80) Read the entire page →
From page 44... ... 44 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads 3.4.4 Multiple Presence Factor A multiple presence factor (MPF) for bridges may be defined as: 1 (3.6) Read the entire page →
From page 45... ... research program 45 centrifugal forces calculated by the equations specified in AASHTO LRFD BDS and AREMA. In general, the AREMA approach underestimated the centrifugal forces resulting from the Utah axle load. Read the entire page →
From page 46... ... 46 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads where W is the weight of the light rail train. Because all wheels of light rail trains are powered, a slope of up to 7% may not cause any problem in train operation (Parsons Brinckerhoff et al. Read the entire page →
From page 47... ... research program 47 6.0 × 10-6/°F, respectively. The variation of temperature in steel rails was assumed to be 150°F. Read the entire page →
From page 48... ... 48 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads a = the CTE of the rail (a = 6.5 × 10-6/°F) ; DT = the temperature variation; Nclip = the number of rail clips on the fastener (Nclip = 2) Read the entire page →
From page 49... ... research program 49 strength of 60 ksi. Detailed information on the AAR-1B was obtained from TCRP Report 151; for example, wheel diameter = 28 in., wheel gage = 55.7 in., and wheel back to back = 53.4 in. Read the entire page →
From page 50... ... 50 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads representative trains was lower than the proposed DLA of 30% and the 33% of AASHTO LRFD BDS. Figure 3.137(b) Read the entire page →
From page 51... ... research program 51 recommendations, the responses of the bridges can be tested if they belong to one of these design guidelines or both, as explained earlier in ANOVA. In so doing, unified approaches for light rail train and standard highway vehicle loadings can be developed to facilitate the design of bridge structures carrying these two distinct live loads. Read the entire page →
From page 52... ... 52 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads 3.6.2.3 Response Comparison of Light Rail Bridges The statistical responses of the light rail bridges was compared with one another, as shown in Table 3.40. The purpose of this comparison was to identify a potential difference in bridge behavior along with certain design parameters. Read the entire page →
From page 53... ... research program 53 Table 3.41 summarizes the coefficient of variation of the resistance (VR) for the bridge structures considered in this calibration. Read the entire page →
From page 54... ... 54 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads 3.7.1.2 Fatigue I and II Fatigue I is intended to avoid fatigue cracking when subjected to infinitely many fatigue cycles along with stress ranges below an endurance limit. The ratio between the response of a bridge at an occurrence probability of 1/10,000 (Z = 3.719) Read the entire page →
From page 55... ... research program 55 3.7.2.3 Load Factors for Fatigue I and II Figure 3.142(a) illustrates the variation of Fatigue I load factors with span length. Read the entire page →
From page 56... ... 56 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads Bridge Type Typical cross section Spans modeled Materials Speeda Broadway Steel plate girder 2 spans (278 ft) • Concrete deck: f'c = 4,500 psi • Structural steel: Fy = 36 ksi 23.4 mph Indiana Prestressed concrete box 5 spans (628 ft) Read the entire page →
From page 57... ... research program 57 Type Schematica Typeb Span length Girder spacing Number of span Skew angle Radius of curvature Steel plate girder a 80 ft 100 ft 140 ft 160 ft 4 ft 6 ft 8 ft 10ft 1 2 3 0° 20° 40° 60° 500 ft 1000 ft 1500 ft Cast-in-place concrete multicell box c 80 ft 100 ft 140 ft 8 ft 10 ft 12 ft 1 2 3 0° 20° 40° 60° 500 ft 1000 ft 1500 ft Cast-in-place concrete T beam e 30 ft 50 ft 70 ft 4 ft 6 ft 8 ft 10 ft 1 2 3 0° 20° 40° 60° N/A Precast concrete I or bulb-tee k 80 ft 100 ft 140 ft 4 ft 6 ft 8 ft 10 ft 1 0° 20° 40° 60° N/A Closed steel boxes b 80 ft 100 ft 140 ft 6 ft 8 ft 10 ft 1 2 3 0° 20° 40° 60° 500 ft 1000 ft 1500 ft a: Schematic taken from the AASHTO LRFD Specifications (Table 4.6.2.2.1-1) Read the entire page →
From page 58... ... 58 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads L (ft) Read the entire page →
From page 59... ... research program 59 Span L (ft) Read the entire page →
From page 60... ... 60 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads Bending moment (k-ft) : one-track loaded Inference based on site load Inference based on the candidate standard live load models Broadway County Line Santa Fe Indiana 6 th Avenue Broadway County Line Santa Fe Indiana 6th Ave Each Ratio Each Ratio Each Ratio Each Ratio Each Ratio Average 1319 1303 1463 779 615 1329 0.99 1416 0.92 2142 0.68 934 0.83 1359 0.45 Upper 20% 1420 1540 1600 900 830 1620 0.88 1711 0.90 2573 0.62 1140 0.79 1671 0.50 99.9% 1707 2172 1962 918 1402 2040 0.84 2153 1.01 3232 0.61 1439 0.64 2112 0.66 75-year 1953 2740 2283 1058 1912 2499 0.78 2630 1.04 3939 0.58 1764 0.60 2596 0.74 Ratio = Inference based on site load/Inference based on the candidate standard live load models × 100 (%) Read the entire page →
From page 61... ... No. City Train length (ft) Read the entire page →
From page 62... ... No. City Train length (ft) Read the entire page →
From page 63... ... research program 63 PC Box d One lane 45.035.0 11 6.3 75.1 cNL S Two or more lanes 25.03.0 1 8.5 13 L S Nc ( 0.130.7 S ) Read the entire page →
From page 64... ... 64 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads PC Box d Regardless of number of lanes 14 eWg ( SWe ) One-track-loaded 28.195 eWg Two-track-loaded 16.745 eWg PC I k One lane Lever Rule Two or more lanes g = eginterior 1.9 77.0 ede ( 5.50.1 ed ) Read the entire page →
From page 65... ... research program 65 PC Box d One lane Lever Rule Two or more lanes g = eginterior 5.12 64.0 ede ( 0.50.2 ed ) One-track-loaded g = eginterior 1.296 3.331* Read the entire page →
From page 66... ... 66 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads PC Box d One lane 1.06.0 0.125.9 L dS Two or more lanes 3.09.0 0.123.7 L dS ( 0.130.6 S ) Read the entire page →
From page 67... ... research program 67 PC I L = 80 ft L = 100 ft L = 140 ft Bending Shear Bending Shear Bending Shear Ext Int Ext Int Ext Int Ext Int Ext Int Ext Int LRT 1 0.06 0.34 0.00 0.57 0.07 0.32 0.00 0.52 0.09 0.27 0.00 0.47 LRT 2 0.11 0.44 0.00 0.61 0.12 0.43 0.00 0.60 0.14 0.40 0.00 0.58 Case 1 0.28 0.54 0.14 0.79 0.29 0.52 0.15 0.77 0.31 0.47 0.17 0.74 Case 2 0.81 0.70 1.05 0.81 0.79 0.68 1.04 0.80 0.76 0.66 1.04 0.75 Case 3 0.86 0.75 1.08 0.83 0.85 0.74 1.08 0.82 0.83 0.72 1.07 0.78 Case 4 0.91 0.80 1.10 0.84 0.90 0.80 1.08 0.84 0.89 0.78 1.08 0.78 Case 5 0.32 0.60 0.15 0.82 0.34 0.58 0.16 0.81 0.37 0.55 0.18 0.78 Case 6 0.32 0.62 0.14 0.77 0.33 0.61 0.14 0.76 0.36 0.58 0.16 0.76 Case 7 0.36 0.69 0.14 0.81 0.38 0.69 0.15 0.81 0.42 0.68 0.17 0.81 Case 8 0.83 0.73 1.00 0.79 0.81 0.72 0.99 0.80 0.79 0.71 0.99 0.79 Case 9 0.88 0.78 1.03 0.82 0.87 0.78 1.03 0.83 0.86 0.78 1.02 0.82 Case 10 0.93 0.84 1.05 0.83 0.93 0.84 1.05 0.84 0.92 0.84 1.03 0.83 Case 11 0.84 0.67 1.08 0.83 0.82 0.65 1.08 0.83 0.79 0.61 1.07 0.78 Table 3.26. Summary of controlling live load distribution factors for prestressed concrete I bridges subjected to a combination of light rail train and HL-93 loadings (2+2+2 loading case) Read the entire page →
From page 68... ... 68 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads ST Plate L = 80 ft L = 100 ft L = 140 ft L = 160 ft Bending Shear Bending Shear Bending Shear Bending Shear Ext Int Ext Int Ext Int Ext Int Ext Int Ext Int Ext Int Ext Int LRT 1 0.07 0.31 0.00 0.49 0.07 0.30 0.00 0.48 0.09 0.27 0.00 0.47 0.09 0.26 0.00 0.46 LRT 2 0.11 0.49 0.00 0.61 0.12 0.47 0.00 0.60 0.14 0.45 0.00 0.59 0.15 0.44 0.00 0.59 Case 1 0.28 0.52 0.17 0.75 0.29 0.50 0.17 0.74 0.31 0.46 0.17 0.73 0.30 0.46 0.16 0.73 Case 2 0.77 0.71 1.05 0.78 0.77 0.70 1.05 0.77 0.76 0.66 1.04 0.75 0.74 0.66 0.98 0.78 Case 3 0.82 0.76 1.08 0.80 0.82 0.74 1.05 0.77 0.83 0.72 1.05 0.76 0.83 0.71 1.05 0.76 Case 4 0.87 0.82 1.09 0.80 0.88 0.80 1.09 0.80 0.89 0.78 1.08 0.78 0.89 0.78 1.06 0.77 Case 5 0.33 0.58 0.18 0.78 0.35 0.57 0.18 0.77 0.37 0.54 0.19 0.76 0.37 0.54 0.22 0.77 Case 6 0.32 0.62 0.16 0.76 0.33 0.60 0.16 0.76 0.36 0.58 0.15 0.76 0.37 0.58 0.15 0.77 Case 7 0.36 0.70 0.17 0.81 0.39 0.69 0.17 0.81 0.42 0.68 0.18 0.81 0.44 0.67 0.21 0.81 Case 8 0.78 0.74 1.01 0.79 0.78 0.73 1.01 0.79 0.78 0.71 1.00 0.78 0.77 0.71 0.94 0.80 Case 9 0.83 0.79 1.03 0.83 0.84 0.78 1.04 0.83 0.86 0.78 1.03 0.82 0.88 0.78 0.97 0.83 Case 10 0.89 0.85 1.05 0.85 0.91 0.85 1.05 0.84 0.93 0.85 1.04 0.83 0.95 0.85 1.06 0.83 Case 11 0.78 0.65 1.08 0.79 0.79 0.64 1.08 0.79 0.79 0.61 1.07 0.77 0.81 0.61 1.06 0.77 Table 3.29. Summary of controlling live load distribution factors for steel plate bridges subjected to a combination of light rail train and HL-93 loadings (2+2+2 loading case) Read the entire page →
From page 69... ... PC Box L = 80 ft L = 100 ft L = 140 ft Bending Shear Bending Shear Bending Shear Ext Int Ext Int Ext Int Ext Int Ext Int Ext Int LRT 1 0.07 0.24 0.01 0.58 0.09 0.23 0.03 0.53 0.10 0.19 0.03 0.49 LRT 2 0.12 0.39 0.01 0.68 0.14 0.38 0.04 0.67 0.16 0.33 0.05 0.64 Case 1 0.21 0.43 0.04 0.72 0.22 0.38 0.09 0.66 0.26 0.37 0.11 0.63 Case 2 0.43 0.65 0.18 0.91 0.42 0.59 0.26 0.86 0.38 0.51 0.29 0.83 Case 3 0.77 0.92 0.70 1.19 0.70 0.83 0.73 1.14 0.60 0.71 0.78 1.10 Case 4 0.80 0.97 0.70 1.18 0.75 0.9 0.73 1.14 0.65 0.80 0.79 1.11 Case 5 0.82 1.01 0.70 1.18 0.78 0.95 0.73 1.15 0.70 0.90 0.79 1.11 Case 6 0.84 1.04 0.72 1.21 0.80 1.00 0.75 1.18 0.78 0.97 0.81 1.13 Case 7 0.24 0.50 0.04 0.76 0.26 0.49 0.10 0.70 0.29 0.45 0.12 0.68 Case 8 0.25 0.56 0.05 0.82 0.29 0.55 0.10 0.78 0.32 0.48 0.12 0.77 Case 9 0.47 0.72 0.19 0.91 0.55 0.77 0.26 0.87 0.47 0.67 0.30 0.86 Case 10 0.81 0.99 0.69 1.18 0.76 0.92 0.73 1.14 0.67 0.82 0.78 1.11 Case 11 0.84 1.04 0.69 1.18 0.80 1.11 0.73 1.15 0.74 1.02 0.78 1.11 Case 12 0.87 1.08 0.69 1.18 0.84 1.04 0.73 1.15 0.80 1.00 0.79 1.12 Case 13 0.88 1.11 0.71 1.21 0.85 1.11 0.75 1.18 0.82 1.08 0.80 1.14 Case 14 0.28 0.65 0.05 0.86 0.30 0.64 0.11 0.84 0.35 0.59 0.12 0.82 Table 3.32. Summary of controlling live load distribution factors for prestressed concrete box bridges subjected to a combination of light rail train and HL-93 loadings (3+2+3 loading case) Read the entire page →
From page 70... ... 70 proposed aaShtO LrFD Bridge Design Specifications for Light rail transit Loads RC L = 30 ft L = 50 ft L = 70 ft Bending Shear Bending Shear Bending Shear Ext Int Ext Int Ext Int Ext Int Ext Int Ext Int LRT 1 0.03 0.55 0.00 0.76 0.05 0.37 0.00 0.68 0.06 0.29 0.00 0.62 LRT 2 0.04 0.66 0.00 0.77 0.07 0.54 0.00 0.66 0.10 0.40 0.00 0.56 Case 1 0.10 0.74 0.00 0.86 0.14 0.56 0.04 0.83 0.17 0.46 0.04 0.77 Case 2 0.28 0.82 0.17 0.91 0.31 0.72 0.20 0.82 0.38 0.59 0.21 0.82 Case 3 0.81 0.93 1.12 0.97 0.80 0.98 1.07 0.93 0.87 0.86 1.04 0.92 Case 4 0.88 0.93 1.06 1.01 0.78 0.84 1.05 0.96 0.77 0.84 1.05 0.93 Case 5 0.82 1.02 1.12 0.98 0.84 0.97 1.12 0.96 0.86 0.86 1.06 0.93 Case 6 0.84 1.07 1.12 0.97 0.87 1.06 1.11 0.97 0.90 0.90 1.06 0.93 Case 7 0.11 0.79 0.01 0.87 0.16 0.64 0.04 0.85 0.20 0.53 0.05 0.79 Case 8 0.11 0.85 0.01 0.86 0.15 0.61 0.01 0.86 0.16 0.61 0.01 0.79 Case 9 0.29 0.94 0.17 0.90 0.36 0.82 0.23 0.81 0.41 0.66 0.27 0.77 Case 10 0.82 1.04 1.11 0.97 0.86 0.95 0.97 0.89 0.9 0.82 0.96 0.84 Case 11 0.83 1.10 1.12 0.98 0.84 0.94 1.12 0.98 0.86 0.86 1.03 0.90 Case 12 0.86 1.13 1.05 0.97 0.87 1.01 0.99 0.93 0.94 0.92 0.58 0.51 Case 13 0.85 1.19 1.12 0.97 0.92 1.03 1.03 0.95 0.92 0.93 1.03 0.91 Case 14 0.13 0.91 0.01 0.87 0.17 0.74 0.11 0.75 0.17 0.66 0.14 0.75 Table 3.35. Summary of controlling live load distribution factors for reinforced concrete bridges subjected to a combination of light rail train and HL-93 loadings (3+2+3 loading case) Read the entire page →
From page 71... ... Research Program 71 Parameter Variable F Technical interpretation Each F0.05 Bearing arrangement Two-span 0.33 4.26 Bridge responses are not different Three-span 0.12 3.49 Bridge responses are not different Centrifugal force (CE) Radius (PC Box) Read the entire page →
From page 72... ... Parameter Category F Technical interpretation Each F0.05 Braking force (BR) AASHTO LRFD 5.02 2.353 AASHTO BR is different from model data Proposed 1.03 2.353 Proposed BR is not different from model data Centrifugal force (CE) Read the entire page →
From page 73... ... Parameter Category F Technical interpretation Each F0.05 Proposed (ST Box: V, θ = 0o) 0 1.740 Proposed SK is not different from model data AASHTO LRFD (ST Plate: V, θ = 0o) Read the entire page →
From page 74... ... 74 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads Parameter Category F Technical interpretation Each F0.05 AASHTO LRFD (RC: V, θ = 40o) 8.82 1.714 AASHTO SK is different from model data Proposed (RC: V, θ = 40o) Read the entire page →
From page 75... ... Parameter Category F Technical interpretation Each F0.05 PC Box (Proposed: V- Ext) 0.02 1.740 Proposed LDF is not different from model data PC I (Lever rule: V- Ext) Read the entire page →
From page 76... ... 76 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads Parameter Category F Technical interpretation Each F0.05 Bearing arrangement Two-span (Case a) N/A N/A Reference case for other bridges Two-span (Case b) Read the entire page →
From page 77... ... Research Program 77 Parameter Category F Technical interpretation Each F0.05 Skewed bridge Moment (θ = 0o) N/A N/A Reference case for other bridges Moment (θ = 20o) Read the entire page →
From page 78... ... 78 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (a) Read the entire page →
From page 79... ... Research Program 79 Theory Load Test Empty train Full train Test Theory Empty train Full train Load (b) Read the entire page →
From page 80... ... 80 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads Strain gages (a) Laboratory: empty train (b) Read the entire page →
From page 81... ... Research Program 81 Monitored span (a) Read the entire page →
From page 82... ... Monitored span (a) Read the entire page →
From page 83... ... Research Program 83 (a) Read the entire page →
From page 84... ... 84 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (c) Read the entire page →
From page 85... ... Research Program 85 (e) Figure 3.13. Read the entire page →
From page 86... ... 86 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (a) Read the entire page →
From page 87... ... Figure 3.16. Normality test of the Broadway Bridge. Read the entire page →
From page 88... ... 88 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (a) Read the entire page →
From page 89... ... Research Program 89 (c) Read the entire page →
From page 90... ... 90 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (a) Read the entire page →
From page 91... ... Research Program 91 (e) μ = 0.33 V = 0.47 μ = 0.26 V = 0.43 μ = 0.27 V = 0.53 μ = 0.27 V = 0.43 μ = 0.26 V = 0.61 μ = 0.20 V = 0.68 μ = 0.22 V = 0.01 μ = 0.27 V = 0.06 μ = 0.37 V = 0.26 μ = 0.41 V = 0.15 μ = 0.38 V = 0.22 μ = 0.35 V = 0.17 μ = 0.11 V = 0.01 μ = 0.14 V = 0.06 μ = 0.19 V = 0.26 μ = 0.21 V = 0.15 μ = 0.19 V = 0.22 μ = 0.17 V = 0.17 Figure 3.19. Read the entire page →
From page 92... ... 92 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (d) Read the entire page →
From page 93... ... Research Program 93 Walkway Steel I girder Deck slab Bearing Direct ﬁxation track Bearing Bearing Walkway Deck slab Pier cap Steel I girder (a) Modeled spans Bearing Direct ﬁxation track Prestressed concrete box girder Bearing Pier Prestressed concrete box girder WalkwayWalkway Direct ﬁxation track Pier (b) Read the entire page →
From page 94... ... 94 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (e) Modeled spans Bearing Prestressed concrete Pier cap Deck slab Walkway Bearing Prestressed concrete Deck slab Direct ﬁxation track Prestressing strands Modeled spans Bearing Prestressed concrete Ballast track Precast element Prestressing strands Bearing Prestressed concrete Ballast track Ballast link (d) Read the entire page →
From page 95... ... Research Program 95 Load case 1 Load case 2 Load case 3 (a) Load case 1 (b) Read the entire page →
From page 96... ... 96 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (e) Load case 1 Load case 2 Load case 3 Load case 2Load case 1 (d) Read the entire page →
From page 97... ... Research Program 97 (c) Read the entire page →
From page 98... ... 98 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads 4.719.254.71 9.254.71 4.71 4.714.71 9.25 32 9.254.71 4.71 6 4 44 4 4 4 6 32 32 32 4 6 6 6 6 4 4 8 8 8 6 10 10 6 (a) Read the entire page →
From page 99... ... Research Program 99 (a) Read the entire page →
From page 100... ... 100 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads 8 ft spacing (4 webs) 12 ft spacing (3 webs) Read the entire page →
From page 101... ... Research Program 101 (d) Read the entire page →
From page 102... ... 102 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads Hollow: 1-track loaded (c) Hollow: 1-track loaded (d) Read the entire page →
From page 103... ... Research Program 103 Hollow: 1-track loaded (c) Hollow: 1-track loaded (d) Read the entire page →
From page 104... ... 104 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads Solid: 2-track loaded Hollow: 1-track loaded (a) Solid: 2-track loaded Hollow: 1-track loaded (b) Read the entire page →
From page 105... ... Research Program 105 Solid: 2-track loaded Hollow: 1-track loaded (a) Solid: 2-track loaded Hollow: 1-track loaded (b) Read the entire page →
From page 106... ... 106 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (d) Read the entire page →
From page 107... ... Research Program 107 93HL trainraillight M M 93HL trainraillight M M 93HL trainraillight M M 93HL trainraillight M M (j) Read the entire page →
From page 108... ... 108 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads Solid: 2-track loaded Hollow: 1-track loaded (a) Read the entire page →
From page 109... ... Research Program 109 (a) Read the entire page →
From page 110... ... 110 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (a) Read the entire page →
From page 111... ... Research Program 111 (g) Read the entire page →
From page 112... ... 112 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (a) Read the entire page →
From page 113... ... Research Program 113 (a) Read the entire page →
From page 116... ... 116 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (a) Read the entire page →
From page 117... ... Research Program 117 (e) Read the entire page →
From page 118... ... 118 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads 288 load cases 75-year 99.9% 90.0% 75-year 99.9% 90.0% 384 load cases 288 load cases 75-year 99.9% 90.0% 75-year 99.9% 90.0% 512 load cases 75-year 99.9% 90.0% 384 load cases (e) Read the entire page →
From page 119... ... Upper 20% load RC (9,600 load cases) Steel Box(7,200 load cases) Read the entire page →
From page 120... ... 120 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (c) Read the entire page →
From page 121... ... Research Program 121 Existing design loadsCandidate design loads (with lane load along 28 ft only) Figure 3.60. Read the entire page →
From page 122... ... 122 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (i) Read the entire page →
From page 123... ... Research Program 123 (a) Read the entire page →
From page 124... ... 124 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (g) Read the entire page →
From page 125... ... Research Program 125 75-year 99.9% 90.0% 75-year 99.9% 90.0% 75-year 99.9% 90.0% 75-year 99.9% 90.0% 75-year 99.9% 90.0% Upper 20% moment (a) Read the entire page →
From page 126... ... 126 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (a) Read the entire page →
From page 127... ... Research Program 127 P1 P2 4PP3 a b c d Train 1 Four-axle trains Six-axle trains Eight-axle trains P 2P1 4P3 P P5 6P P8P7 9P 10P Ten-axle trains Train 2 P P P P1 2 3 4 a b c Train 1 Train 2 3PPP1 2 P4 PP5 6 a b c b a d a b bc a P PPP P P21 3 4 5 6 Train 1 Train 2 P P P P1 2 3 4 65 PP P7P 8 P21 PP P3P 4 65 P 87P P a b c d c b a e a cb d bc a P21 PP P3P 4 65 P 87P P P P9 10 a cb d c e c f a g a b c cd e fc a Train 1 Train 2 Figure 3.66. Dimensional configuration of light rail trains used for load-enveloping assessment. Read the entire page →
From page 128... ... 128 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (c) Read the entire page →
From page 129... ... Research Program 129 (b) Read the entire page →
From page 130... ... 130 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads 216 load cases AREMA (L/640) Read the entire page →
From page 131... ... Research Program 131 (a) Read the entire page →
From page 132... ... 132 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (a) Read the entire page →
From page 134... ... 134 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (a) Read the entire page →
From page 135... ... Research Program 135 (a) Read the entire page →
From page 136... ... 136 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (g) Read the entire page →
From page 137... ... Research Program 137 (a) Read the entire page →
From page 138... ... 138 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (g) Read the entire page →
From page 139... ... Research Program 139 (a) Read the entire page →
From page 141... ... Research Program 141 (a) Read the entire page →
From page 142... ... 142 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads Figure 3.81. Bending moment distribution of prestressed concrete I girder bridges subjected to a combination of light rail train and HL-93 loadings (2+2+2 loading case) Read the entire page →
From page 143... ... Research Program 143 Figure 3.82. Shear force distribution of prestressed concrete I girder bridges subjected to a combination of light rail train and HL-93 loadings (2+2+2 loading case) Read the entire page →
From page 144... ... 144 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads Figure 3.83. Bending moment distribution of prestressed concrete box girder bridges subjected to a combination of light rail train and HL-93 loadings (2+2+2 loading case) Read the entire page →
From page 145... ... Research Program 145 Figure 3.84. Shear force distribution of prestressed concrete box girder bridges subjected to a combination of light rail train and HL-93 loadings (2+2+2 loading case) Read the entire page →
From page 146... ... 146 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads Girder number: Steel Box (L = 100 ft) Girder number: Steel Box (L = 100 ft) Read the entire page →
From page 147... ... Research Program 147 Girder number: Steel Box (L = 100 ft) Girder number: Steel Box (L = 100 ft) Read the entire page →
From page 148... ... 148 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads Figure 3.87. Bending moment distribution of steel plate girder bridges subjected to a combination of light rail train and HL-93 loadings (2+2+2 loading case) Read the entire page →
From page 149... ... Research Program 149 Figure 3.88. Shear force distribution of steel plate girder bridges subjected to a combination of light rail train and HL-93 loadings (2+2+2 loading case) Read the entire page →
From page 150... ... 150 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads Figure 3.89. Bending moment distribution of reinforced concrete girder bridges subjected to a combination of light rail train and HL-93 loadings (2+2+2 loading case) Read the entire page →
From page 151... ... Research Program 151 Figure 3.90. Shear force distribution of reinforced concrete girder bridges subjected to a combination of light rail train and HL-93 loadings (2+2+2 loading case) Read the entire page →
From page 152... ... 152 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads Figure 3.91. Bending moment distribution of prestressed concrete I girder bridges subjected to a combination of light rail train and HL-93 loadings (3+2+3 loading case) Read the entire page →
From page 153... ... Research Program 153 Figure 3.92. Shear force distribution of prestressed concrete I girder bridges subjected to a combination of light rail train and HL-93 loadings (3+2+3 loading case) Read the entire page →
From page 154... ... 154 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads Figure 3.93. Bending moment distribution of prestressed concrete box girder bridges subjected to a combination of light rail train and HL-93 loadings (3+2+3 loading case) Read the entire page →
From page 155... ... Research Program 155 Figure 3.94. Shear force distribution of prestressed concrete box girder bridges subjected to a combination of light rail train and HL-93 loadings (3+2+3 loading case) Read the entire page →
From page 156... ... 156 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads Figure 3.95. Bending moment distribution of steel box girder bridges subjected to a combination of light rail train and HL-93 loadings (3+2+3 loading case) Read the entire page →
From page 157... ... Research Program 157 Figure 3.96. Shear force distribution of steel box girder bridges subjected to a combination of light rail train and HL-93 loadings (3+2+3 loading case) Read the entire page →
From page 158... ... 158 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads Figure 3.97. Bending moment distribution of steel plate girder bridges subjected to a combination of light rail train and HL-93 loadings (3+2+3 loading case) Read the entire page →
From page 159... ... Research Program 159 Figure 3.98. Shear force distribution of steel plate girder bridges subjected to a combination of light rail train and HL-93 loadings (3+2+3 loading case) Read the entire page →
From page 160... ... 160 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads Figure 3.99. Bending moment distribution of reinforced concrete girder bridges subjected to a combination of light rail train and HL-93 loadings (3+2+3 loading case) Read the entire page →
From page 161... ... Research Program 161 Figure 3.100. Shear force distribution of reinforced concrete girder bridges subjected to a combination of light rail train and HL-93 loadings (3+2+3 loading case) Read the entire page →
From page 162... ... 162 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (c) Read the entire page →
From page 163... ... Research Program 163 (g) Read the entire page →
From page 164... ... 164 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (c) Read the entire page →
From page 165... ... Research Program 165 (g) Read the entire page →
From page 166... ... 166 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (c) Read the entire page →
From page 167... ... Research Program 167 (a) Read the entire page →
From page 168... ... 168 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (a) Read the entire page →
From page 169... ... Research Program 169 (c) Read the entire page →
From page 170... ... 170 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (a) Read the entire page →
From page 171... ... Research Program 171 75-year 99.9% 90.0% 288 load cases 75-year 99.9% 90.0% 384 load cases 75-year 99.9% 90.0% 512 load cases (e) Read the entire page →
From page 172... ... 172 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (c) Read the entire page →
From page 173... ... Research Program 173 Maximum + ve moment for interior span Six axle articulated train Figure 3.111. Simultaneous loading on a two-track steel plate girder bridge (L = 160 ft) Read the entire page →
From page 174... ... 174 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (e) Read the entire page →
From page 175... ... Research Program 175 (a) Read the entire page →
From page 176... ... 176 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads PC Box PC Box PC I PC I (a) Read the entire page →
From page 177... ... Research Program 177 Reinforced Concrete Reinforced Concrete Steel Plate Steel Plate (g) Read the entire page →
From page 178... ... 178 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (a) Read the entire page →
From page 179... ... Research Program 179 (a) Read the entire page →
From page 180... ... 180 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (f) Read the entire page →
From page 181... ... Research Program 181 TCRP 155 range TCRP 155 upper limit TCRP 155 lower limit TCRP 155 average (a) Read the entire page →
From page 182... ... Figure 3.123. Comparison of longitudinal braking force ratios between AASHTO LRFD and the proposed standard live load model. Read the entire page →
From page 183... ... Research Program 183 Temperature variation (steel) Moderate: 0°F to 120°F Cold: -30°F to 120°F Figure 3.126. Read the entire page →
From page 184... ... 184 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (a) Read the entire page →
From page 185... ... Research Program 185 (a) Case a Train Train Case b Train Case c F E E E E E EF F Train Train Train Case a Case c Case b Case d Train F F FF E E E E E E E E E E E (b) Read the entire page →
From page 186... ... 186 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (a) Read the entire page →
From page 187... ... Research Program 187 0.02 sec 0.04 sec 0.06 sec 0.10 sec0.08 sec Figure 3.135. Vertical stress contour of simulated wheel-rail system moving at 60 mph. Read the entire page →
From page 189... ... Research Program 189 Figure 3.141. Evaluation of load factors (Strength I) Read the entire page →
From page 190... ... 190 Proposed AASHTO LRFD Bridge Design Specifications for Light Rail Transit Loads (a) Read the entire page →

From page 21...

... 21 C h a p t e r 3 The details of technical approaches and results are provided in this section. Major parameters related to bridge types, load effects, and forces associated with rail–train–structure interaction are studied.