Laserfiche WebLink
The manhole shall provide an area from which a grade ring can be installed to accept a 30-inch <br />diameter metal ring and cover and have the strength to support H-20 traffic loading without <br />darnage to the ring, cover, or manhole. The grade ring should be extended past the perimeter of <br />the manhole at least 1-inch in order to transfer as much of the load as practical to the exterior <br />wall of the manhole. <br />Exterior and interior surfaces shall be free of delaminations, bubbles, wrinkles, or exposed fibers. <br />Do not lift the manhole with direct contact with chains or cable. <br />Manholes shall have the anti-floatation ring to be set in 3,000 psi concrete a minimum of 4- <br />inches. The manholes shall be mechanically tamped backfill per the mechanical tamped backfill <br />specification located elsewhere herein, or backfilled with crushed stone. <br />Manhole Castin~s <br />Manhole cover and frame shall be PAMREX or approved equal. Cover and frame shall be <br />manufactured from ductile iron. Covers shall be hinged and incorporate a 90-degree blocking <br />system to prevent accidental closure and come complete with hinge infiltration plug. Covers <br />shall be one-man operable using standard tools and shall be capable of withstanding a test load of <br />120,000 lbs. Frames shall be circular and shall incorporate a seating ring, and have a 30-inch <br />clear opening. The frame depth shall not exceed 4-inches, and the flange shall incorporate <br />bedding slots and bolt holes. All components shall be black asphalt coated. <br />Mazking indicating "Sanitary Sewer" or "Sewer" cast onto the cover is required. <br />Ribs will be cast on the underside of the cover as needed, for reinforcement. <br />The combined ring and cover weight shall not be less than 195 pounds. <br />Recommended source is through James Cox with Jim Cox Sales, Inc, (817) 501-5832. <br />CONTRACTORS providing other than Pamrex shall include inflow inserts specified elsewhere <br />herein. <br />Manhole Drop Structures <br />Where the incoming and outgoing sewers in manholes have a difference in flowline elevations <br />exceeding 30" (unless shown otherwise on drawings), the incoming sewer will have an outside <br />drop as per the detail drawings. The concrete manhole base will be enlarged to extend under the <br />drop section. T'he drop section shall be made of standard pipe and fittings, which shall be <br />completely encased in concrete resting on the enlazged manhole base. <br />93 <br />