This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
In Fig. 211 is shown a section of one of the branch sewers that is being constructed in the Borough of the Bronx, New York City. A large part of this sewer is located in a salt marsh where water and unstable soil make construction work very difficult. The general elevation of the marsh is 1.5 feet above mean high water. In constructing this sewer in the marsh, it is necessary to construct a pile foundation to support the sewer The foundation is capped with reinforced concrete; and then the sewer, as shown in the section, is constructed on the pile foundation. The concrete for this work is composed of 1 part Portland cement, 2 1/2 parts sand, and 5 parts trap rock. The rock was crushed to pass a 3/4-inch screen. "Ransome" twisted bars were used for the reinforcement in this work.