Grand Housing Development Program Volume III - Gtz

THE MANHOLEBottom-view (left) and top-view (right) of the mould withfrog for the chuteThere is also a formwork for the manholes. It consistsof four metal side-panels, two plastic pipes and a rectangularpot. The side-panels are fixed by four anglebars in the corners using clamps as described above.The pipes are fitted on different levels, so that backpressure can not reach the intake.Formworkfor themanhole,viewedfrom theside ofintake(front panelremoved)Viewedfrom top(panel ofintake-sideremoved)The pot is slightly tapered and has a groove at the bottomto form a chute for the future catch drain.All parts are treated with waste oil to make removaleasier.One has to be sure to make the pit for the manholebig enough to be able to draw out the pipes after castingthe concrete. Moreover, one has to foresee enoughspace in the pit for 3 persons to place and remove theformwork.The mouldviewedfrom theside of thecatch drain(front panelremoved)The castmanholeand thepit for themanholeFROM TECHNICAL MANUALS VOL I AND II MACHINERY, TOOLS AND BASIC TECHNIQUES21Addis AbabaCity Government