The most commonly used sewer under culverts is
Detailed Solution:
types of sewer
circular brick sewer is used under culverts and at such places where big diameter is required for short lengths. this sections are plastered from inside. In olden days these were common, but now a days these are not used due to their much wear and difficult centring
semi elliptical sewer is suitable for sewers carrying large discharges throughout the year, These ara usually constructed with RCC
horse shoe sewer is constructed with RCC and is used in case of heavy discharges, the height is less than its width
egg shaped sewer is the sewer having depth one and half time their width. best for self cleansing