Profile of TProfile of T--beam Bridges in PAbeam Bridges in PA

n Total Number in USA > 32,000n Total Number in PA >2600n Type Specific Design

n Built Between ~1930 & 1950n Span ~20 ft -40 ftn Width ~ 20 ft - 40 ftn Skew ~ 0 - 45 degn Slab Thickness ~ 8-8.5 inn Beam Spacing ~ 5 ft on centern Beam Depth ~ 19 in - 40 in

1,651 Single Span T-beam Bridges in PA Standard Design Drawings

Statistical Sampling of TStatistical Sampling of T--beam Bridgesbeam Bridges

15

Bri

dge

Pop

ulat

ion

Degree Skew

Bri

dg

e P

op

ula

tion

Structural Parameters

Bri

dg

e P

op

ula

tio

n

Condition Rating0 1 2 3 4 5 6 7 8 9 10 11

Year Constructed

Bri

dge

Pop

ulat

ion

19481929Location

Condition Parameters

District Engineers' Input for Bridges That Need Evaluation

SPAN

Span (ft)

SKEW

30'

50%

50%25%50%

50%

50% 25%

25%

50%

25%

Load Capacity Rating=F (Nominal Structural Parameters + Condition Parameters)

Model Calibration with Field Test ResultsModel Calibration with Field Test Results

Transverse Centerline Deflection of the Superstructure (Test vs. Models)

Def

lect

ion

(in

)

-0.010

-0.020

-0.030

0

-0.040

-0.050

-0.060

-0.070

Section A-A

A2 B2 C2 D2 E2 F2

-0.010

-0.020

-0.030

0

Def

lect

ion

(in

)

-0.040

-0.050

-0.060

-0.070

Deflection of the T-Beam "C" (Test vs. Models)

Superstructure

C3 C2 C1

Section B-BLoad Test Truck

51.5 kips 48.0 kips

Boundary Condition Idealization of Different Models

Positioning Trucks

Displacement Sensor Location

Steel Strain Sensor Location Concrete Strain Gauge Location

A-A

A B C D E F

3

2

1

CL

CL

B-BK K K K

Calibrated FEM

Truck and Sensor Locations:

a) Instrumentation Plan, Truck Loading and Model Boundary Conditions

b) Regional Calibration and Correlation

Pins @ dowel locations

RFinv=3.18RF inv=2.96 RF inv=3.06

RFinv=2.94RF inv=1.89 RF inv=2.02

AASHTO vs. FEM Based Load RatingAASHTO vs. FEM Based Load Rating

Ratio (FEM/AASHTO) = 5.56

AASHTO Rating = 1.01Field Calibrated FEM = 5.62

Ratio (FEM/AASHTO) = 2.75

AASHTO Rating = 1.22Field Calibrated FEM = 3.35

Ratio (FEM/AASHTO) = 2.50

AASHTO Rating = 1.27Field Calibrated FEM = 3.18

Ratio (FEM/AASHTO) = 3.46

AASHTO Rating = 0.92Field Calibrated FEM = 3.18