Experimental study of real ice accumulation on channel hydraulics upstream of inverted siphons

In cold regions, safe operation of inverted siphons might be threatened if incoming floating ice floes accumulate upstream of the inlet. An experimental study is conducted using real ice particles to simulate the ice accumulation phenomenon. The main objective is to gain a better understanding of the ice accumulation characteristics and the resultant impacts on the flow hydraulics in the upstream channel. The thickness of the ice particles accumulation is measured under different flow conditions. The velocity profiles beneath the accumulated ice particles are also measured and analyzed theoretically to calculate the hydraulic resistance. From the sensitivity analysis, it is found that a good prediction of under-ice depth could be made based on the average values of the ice-affected resistance coefficients. Subsequently, by combining the experimental results with hydraulic calculations, some expressions are derived to calculate the variations of ice-affected hydraulic parameters comparing to that of open-water conditions. From the present study, it is noted that ice accumulation leads to excess headwater that interferes with proper functioning of inverted siphons while causing operational issues by inundating the upstream structures. It is urgently needed to consider ice accumulation impacts in the design of inverted siphons. •Real ice particle accumulation was investigated in front of inverted siphons.•The accumulation thickness and velocity was presented.•Ice affected Manning’s roughness coefficient was analyzed and discussed.