Military

F-1. This appendix contains examples for classifying a bridge using the analytical classification procedure. The following notations are used in this appendix:

F-2. In this example, Table F-1 shows the procedure for classifying a timber-stringer bridge and Table F-2 contains a classification summary. Figure F-1 shows a sample bridge-reconnaissance report for a timber-stringer bridge. Information from an on-site inspection is as follows:

• The bridge is in good condition.
• All members are in good condition.
• The piling and abutment end beams have been treated to reduce deterioration. Therefore, substructure is not rated.
• The bridge is about two years old.
• Each of the three spans are constructed identically, so the longer (17-foot) span will be classified as the weakest span.
• The timber species is dense, select-structural Douglas fir.
• The horizontal splits are no longer than 6 inches.

F-3. In this example, Table F-3 shows the procedure for classifying a steel-stringer bridge and Table F-4 contains a classification summary. Figure F-2 shows a sample bridge-reconnaissance report for a steel-stringer bridge. Information from an on-site inspection is as follows:

• The bridge is in excellent condition.
• The date built is unknown.
• The steel-stringer sections were identified by comparing dimensions with the section properties found in Appendix D.
• The concrete deck does not act to increase the moment capability of the stringers. Therefore, it is noncomposite.

F-4. In this example, Table F-5 shows the procedure for classifying a composite steel-concrete stringer bridge and Table F-6 contains a classification summary. Figure F-3 shows a sample bridge-reconnaissance report, and Figure F-4 shows a composite section of this bridge. Information from an on-site inspection is as follows:

• The bridge is in excellent condition.
• Full lateral support of the stringers is provided by the connection with the concrete deck.
• The steel-stringer sections were constructed from A36 steel (36 ksi yield), according to civilian authorities.
• The concrete allowable stress is 4,000 psi (f'c = 4,000 psi; and r_m = 8).
• S_composite denotes the composite section modulus as determined according to paragraph 3-75.

F-5. In this example, Table F-7 shows the procedure for classifying a steel-girder bridge, and Table F-8 contains a classification summary for a steel-girder bridge. Figure F-5 shows a sample bridge-reconnaissance report for a steel-girder bridge. Figures F-6 and F-7 show details of the girder. According to civilian authorities, the deck is a concrete slab constructed of noncomposite construction.

F-6. In this example, Table F-9 shows the procedure for classifying a truss bridge. Table F-10 contains a classification summary. Figure F-8 shows a sample bridge-reconnaissance report for a truss bridge. Figures F-9 and F-10 show details of the bridge.

F-7. In this example, Table F-11 shows the procedure for classifying a reinforced concrete-slab bridge and Table F-12 contains a classification summary. Figure F-11 shows a sample bridge-reconnaissance report, and Figure F-12 shows the steel-reinforcement details of this bridge. The local civilian bridge authorities provided the following stress values:

• F_y = 50 ksi (grade-50 bars).
• f'c = 3 ksi.

F-8. In this example, Table F-13 shows the procedure for classifying a reinforced concrete T-beam bridge and Table F-14 contains a classification summary. Figure F-13 shows a sample bridge-reconnaissance report, and Figure F-14 shows details of this bridge. The local civilian bridge authorities provided the following stress values:

• F_y = 40 ksi (grade-40 bars).
• f'c = 3 ksi.

F-9. In this example, Table F-15 shows the procedure for classifying a reinforced concrete-box-girder bridge and Table F-16 contains a classification summary. Figure F-15 shows a sample bridge-reconnaissance report, and Figure F-16 shows details of this bridge from as-built civilian drawings. The local civilian bridge authorities provided the following stress values:

• F_y = 50 ksi (grade-50 bars).
• f'c = 4 ksi.

F-10. In this example, the bridge deck is of composite construction. Since the 28-day compressive strength of the deck and stringers is the same, no transformed moment of inertia calculations are required. If the deck were made of ordinary-grade concrete and the precast, prestressed beam made of high-strength concrete, the different moduli of elasticity would have to be considered. Table F-17 shows the procedure for classifying a prestressed concrete bridge, and Table F-18 contains a classification summary. The detailed dimensions and information about the prestressed steel in Figure F-17 were taken from as-built drawings. Figure F-18 shows a sample bridge-reconnaissance report. The local civilian bridge authorities provided the following allowable stress values:

• f_pu = 240 ksi.
• f'c = 5 ksi.

F-11. In this example, Table F-19 shows the measured bridge dimensions, Table F-20 shows the classification procedures, and Table F-21 shows a classification summary for a masonry-arch bridge. Figure F-19 shows a sample bridge-reconnaissance report. Tests show that the arch is made of blue engineering brick. The ring is in good condition with well-mortared joints (about 3/8-inch wide). A small transverse crack was noted within 2 feet of the edge of the ring and there is a slight vertical settlement at one of the abutments.