260 



BRIDGE ABUTMENTS AND PIERS. 



CHAP. VI. 



The materials and workmanship shall comply with the specifications for the highway bridge 

 superstructure. 



Erection. Where the bottom will permit, the tubes shall be sunk well below possible scour 

 by loading the tube and excavating the material from the inside. For this purpose a clamshell 

 bucket is very effective. Driving the tube with a pile driver will cut off the rivets in the horizontal 

 seams and will not be permitted. After the tube is sunk, piles are to be driven inside of the 

 steel shell, as closely together as possible, using care to get no pile nearer than 4 to 6 in. to the 

 steel shell. The piles shall be driven to a good refusal, and the tops sawed off below the low 

 water mark and reaching at least 2. diameters of the tube above the bottom. The space inside the 

 tubes shall then be filled with concrete well tamped. Concrete should not be deposited in running 

 water if possible to prevent it. 



l'-0 



7-0' 



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\AoF Girder-^ \,/tof6ir0er/ 



PILE PLAN 



PLAN 



MASONRY PIEK 

 ILLINOIS CEHTRAL R-R- 



7, .... \Concrete, 

 Quantities \ ., ^ 



FIG. 12. DETAILS OF ILLINOIS CENTRAL RAILROAD PIER. 



Where piers are founded on rock, the tubes are to be anchored to the rock and then filled 

 with concrete. Or cribs may be sunk on the rock and the tube set in a pocket in the crib and 

 resting on the rock. The space outside the tube is then filled with concrete and the tube is filled 

 with concrete in the usual manner. 



Cylinder Piers for Highway Bridge, Trail, B. C.* Steel cylinder piers were used for a steel 

 highway bridge designed by Waddell and Harrington, Consulting Engineers, and built across 

 the Columbia River at Trail, B. C. The main spans are 172 ft. 8 in long and are carried on 

 piers made of two steel cylinders filled with concrete. The steel cylinders are 9 ft. in diameter 

 at the bottom and 6 ft. in diameter at the top, and are 86 ft. long. The cylinders are made of 



* Engineering News, Dec. 5, 1912. 



