MANHOLE CONNECTION DETAIL

1. Maximun allowable trench width to 1 foot above top of pipe is shown in Table 1. If the contractor excavates to a greater width than shown in Table1. He may be expected to provide greater strength pipe and / or concrete encasement as approved by the engineer. no extra payment will be made for these occurances
2. Standard Bedding is to be used for all pipes unless shown or directed by engineer.
3. Whenever concrete backfill or encasement is placed, a transverse break at each pipe joint shall be made as specified to maintain flexibility of the pipe line. Expansion Material shall be full depth and placed in not more than two pieces per break.
4. The deflection at flexible pipe joints shall in addition to the strength requirement not be more than 5 / in the installed position in any direction. It shall be tested for deflection by the contractor in the engineer's presence, as directed by the engineer. Test equipment is to be supplied at no cost to the employer by contractor and approved by the engineer. any section showing deflections above 5 / shall be corrected by the contractor at no expense to the employer.
5. Loading on pipe is developed from marston's theory using :-
   i )   Backfill Density = 120 lbs/ cu . ft.
   ii )  Trench with not exceeding Table 1..
   iii)  Safety factor = 1.5
   iv)  Load factor class 'A' Bedding = 3.0
   v )  Load factor class 'B' Bedding = 1.9
6. Traffic cover refers to min. Cover required before traffic load becomes negligible. Concrete backfill as in class 'A' Bedding is required if min. Cover cannot be achived. and placed in not more than two pieces per break.
7. O.D. = Outer diameter of pipe.
8. All hdpe corrugated (Profile) Double-Wall Sewer pipe shall comform to din 16961.
9. All the rubber sealant ring must be placed onto the second grove from the nearest.  

PIPE EMBEDDED IN CAREFULLY COMPACTED 12mm NOMINAL CRUSHER RUN EXTENDING HALFWAY UP TO THE SIDE OF THE PIPE. THE REMAINER SIDE AND TOP TO BE FILLED AND COMPACTED WITH MONOLITHIC PLAIN CONCRETE.

CLASS 'A' BEDDING

PIPE EMBEDDED IN CAREFULLY COMPACTED 12mm NOMINAL CRUSHER RUN EXTENDING HALFWAY UP TO THE SIDE OF THE PIPE. THE REMAINER SIDE AND TOP TO BE FILLED AND COMPACTED WITH SELECTED BACKFILL.

CLASS 'B' BEDDING

) For Class 'A' Bedding Measured at Top of Concrete Backfill
b) For Class 'B' Bedding Measured at Above Top of Pipe.

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