淤积物固结时间对干容重与起动冲刷的影响

摘要

以三门峡等水库的实测资料为基础，分析了泥沙固结时间与起动流速的关系。结果表明：①粒径为0．01～0．10 mm时，达到稳定干容重所需的时长为0．5～1．2 a，粒径越小，达到稳定的时间越长；②淤积物淤积历时加长、粒径变大及水深增大，将增大起动流速，不利于河道淤积物的冲刷。%This paper analyzed the effect of sediment consolidation time on dry density based on the measured data of Sanmenxia Reservoir and so on,and obtained the steady dry densities of different fine sediments and the time to reach it. The results show that:if the particle size is 0. 01~0. 10 mm,the steady dry density is 1. 8~2. 5 t/m3 ,and the required time is 0. 9~1. 2 a;the smaller the particle size is,the longer the time re-quired to steady dry density is;the incipient velocity of water flow will be increased with the extension of sediment consolidation time,the enlarging of particle size and the heightening of water depth,which brings difficulties to the discharge and scour of river sediments.