Engineering Wonders of the World
Volume I

BEINFORCED CONCRETE CONSTRUCTION. 427 Cross Section Cross Section Fig. 22- DIAGRAM TO SHOW BULGING TENDENCY OF A REINFORCED CONCRETE COLUMN. Fig. 23.—REINFORCED COLUMN BRACED WITH CROSS LINKS TO RESIST BULGING FORCES. and shock caused by the fall of the pile-driving weight, or by the head of the pile-driving engine. The toe is finished by a steel point, so as to enable the pile to penetrate rock and other hard materials encountered in the pro- cess of driving. To people who have been accustomed to deal with plain concrete, which is a brittle substance easily broken across by transverse forces, or smashed by a succession of heavy blows, it must seem a wonderful thing that reinforced concrete piles 50 feet or 60 feet long and little more than 12 inches across can be transported and slung by cranes without being broken, and driven into hard ground as easily as piles of timber or steel. A novel method of pile construction is represented by the Mouchel patent hollow diaphragm reinforced concrete pile, designed as shown in Fig. 29, where the hollow space in the centre is left by the elimination of con- crete from a position where it is of compara- tively little value, thus permitting an equal amount of material to be added on the outside, Fig. 24.—LINKED BARS IN COLUMN ^CAN BEND ONLY BETWEEN LINKS. where it is of great value in resisting pressure, and where it augments the bearing power of the pile by increasing its diameter. Another noteworthy improvement invented by Mr. Mouchel is shown in Fig. 30. It con- sists of one or more piles driven singly or in a cluster, and then converted into a massive pier by lowering a reinforced concrete hollow cylinder over the pile or piles, and filling up the interior space with reinforced concrete. The single pile in Fig. 30 anchors the pier firmly into the ground, which is penetrated for a short distance by the edges of the cyl- inder, and the whole forms a very strong com- bination whose advantages have been proved in various important jetties and piers built within recent years.