4Platzer C, Mauch K . Soil clogging in vertical flow reed beds-mechanism, parameters, consequences and solutions [J]. Wat. Sci. Tech., 1997(35) : 175-181.
5Fisher P J . Hydraulic characteristics of constructed wetlands at Richmond, NSW Australia [M]//Cooper P, F Findlater B C . Constructed Wetlands in Water Pollution Control. Pergamon Press, oxford, 1900.21-31 .
6Tanner C C, James P S . Accumulation of organic solids in gravel-bed constructed wetlands [J] . Wat . Sci . Tech. , 1995, 32(3): 229-239.
7hasca Consulting Group Ine . PFC Particle flow code in three dimensional optional features [ M ] . Minneapolis : [s.n.] , 2005 : 8-9 .
8Potyondya D O, Cundall P A . Abonded-particle model for rock [J] . International Journal of Rock Mechanics & Mining Sciences, 2004(41 ) : 1329-1364 .
9Cho N, Martin C D, Sego D C . A clumped particle model for rock[J] . International Journal of Rock Mechanics & Mining Sciences, 2007(44) : 997-1010 .