International library of technology Volume 98; a series of textbooks for persons engaged in the engineering professions and trades, or for those who desire information concerning them - Tapa blanda

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 Excerpt: ... will settle to the bottom of the catch basin and be retained there. In order to prevent sewer gas from entering the catch basin (from which it would escape in the vicinity of the sidewalk and be very objectionable), the outlet to the sewer is given such a shape as to form a trap. The form of catch basin most common in the United States is shown in Fig. 13. It is generally built of brick or concrete. When built of brick, it should be lined with cement and plastered both inside and outside with cement mortar, so that it will not leak. In the figure, o is the opening for admitting the storm water from the gutter; t is the trap to the outlet leading to the sewer s w is the surface of the water, and m is the deposit of mud and sedimentary refuse; c is a cast-iron cover to an opening in the top of the catch basin, through which the deposited mud and refuse may be removed. It is important that catch basins should be perfectly watertight, so that the water surface may be kept at the proper level. This is necessary, in order both to cover the deposit Fig. li of mud and prevent it from giving off disagreeable gases, and to seal the trap against the escape of sewer gas. The water level in street catch basins should be from 2 to 3 feet below the street surface, and the total depth of the basin should generally be from 6 to 8 feet, in order to avoid freezing. The construction may be varied in detail to suit conditions. FOUNDATIONS 14. Foundations for Pipe Sewers.--Usually, small pipe sewers do not require foundations other than the natural earth at the bottom of the trench. In the case of large sewers in heavy cuttings or in soft and treacherous soil, an artificial foundation may become necessary. Just when such foundations should be used cannot be made a matter of for...