红旗泡水库冰层变形及护坡破杯 现象成因舍析

根据2008 ～ 2009年和2009 ～2010年冬季在红旗泡水库开展的冰层变形和护坡以及附属结构 物破坏现象的现场观测，发现水库冰层有两次爬坡。第一次爬坡发生在入冬封库之后;第二次爬坡发 生在开春快速升温时。两次爬坡的机理不同，分别对应水库结冰体积膨胀和冰层升温热膨胀，两次爬 坡对护坡和附属结构物所产生的破坏程度也不同。文中给出冰层爬坡对护坡破坏程度的描述，并利用 冰层生消过程和冰晶体结构的差异对冰层变形、爬坡原因和破坏能力做出分析。

Settling characteristics and selection of model materials of algal debris particle

The flowing-movement of algal debris particle in the main channel of the Mid-route of South-to-North Water Transfer Project is prone to deposit at the sudden expansion sections of backwater gate，dividing gate，etc. ，thus dredging is necessary to be frequently carried out therein. The settlement and specific gravity characteristics of algal debris particle are studied by means of the technique of particle tracking velocimetry ( PTV) through the static water settlement experiment of algal debris particle under 1set of working condition and the static water settlement experiments of different model materials and different particle sizes under 24 sets of working conditions for exploring the settlement characteristics of different model materials and the selecting the model materials suitable for the field drift tracing test. The study result shows that the static water settling rate of the algal debris particle is 0. 008 m /s with the specific gravity of 1. 004 in water. The larger the particle size of the model material with the same specific gravity is，the larger the static water settling rate is to be. The larger the specific gravities are，the static water settling rates are to be larger too for the model materials with similar or the same particle sizes，while the static water settling rate of the model material with samilar specific gravity is smaller along with the increase of the particle size. The mean particle size of chia seed is 3. 5 mm with the mean specific gravity of 1. 05，of which both the physical and hydrodynamic properties are similar to that of the algal debris particle，and then can be used as the test material for the field drift tracing test made for the algal debris particle in the main channel of South-to-North Water Transfer Project. The study result can provide a technical basis for the algae prevention and control and efficient dredging of the main channel of the Mid-route of South-to-North Water Transfer Project.