Page 430 - Planning and Design of Airports
P. 430

Flexible Pavement  Pipe Cover                         Nominal Diameter of Pipe, in  60  48  42  36  30  24  18  12  60  48  Wheel Load 30,000 lb  4.5  4.5  4.0  3.5  3.0  3.0  3.0  3.0  3.0  2.5  4.0  3.5  3.0  3.0  3.0  2.5  3.0  4.5  2.5  2.5  3.5  3.5  3.5  3.0  3.0  3.0  3.0  3.0  2.0  2.0  3.0  3.0  2.5  2.5  2.


                                   Nominal Diameter of Pipe, in  42  36  Wheel Load 15,000 lb  3.5  2.0  2.5  2.5  2.0  2.0  1.5  1.5  1.0  1.0  2.0  1.5  1.5  1.0  1.0  1.0  1.0







                 24  30  3.5  3.0  2.0  1.5  3.0  2.0  2.5  2.5  2.0  2.0  1.5  1.5  1.0  1.0  1.5  1.5  1.0  1.0  1.0  1.0  1.0  Recommended Minimum Depth of Cover for Pipe, ft


                 18    3.0  1.5  3.0  1.5  2.5  2.0  1.5  1.0  1.5  1.0  1.0


                 12    2.5  1.5  2.5  1.5  2.5  2.0  1.5  1.0  1.0  1.0  1.0





               Kind of Pipe  Clay sewer pipe   Clay culvert pipe  Concrete sewer pipe  Concrete sewer pipe   (extra-strength) Reinforced-concrete culvert pipe   Class I   Class II   Class III   Class IV   Class V Corrugated metal pipe, gauge no.   16   14   12   10     8  TABLE 9-9





                                                                    373
   425   426   427   428   429   430   431   432   433   434   435