流态软土管道流动性质试验研究

在工程中,流态软土常常需要通过管道输送,然而人们并不清楚流态软土管道流动的力学性质。以毛细管试验仪为原型,设计了适合研究软土管道流动特性的仪器,研究了软土含水量、管道长径比、流动速度以及停滞时间对软土管道流动性质的影响。结果表明:同一长径比管道中,随着含水量增大,软土的剪切应力减小、流动性增强;当含水量大于一定值之后,剪切应力几乎不变;随着剪切速率增加,剪切应力变大,但最终会趋于平稳。同一剪切速率下,随着管道长径比增大,剪切应力显著增大。软土在管道中的停滞时间越长,再次启动输送时软土受到的阻力就越大。

Experimental Study on Flow Properties of Soft Clay in Pipeline

Soft clay needs to be transported by pipeline in engineering, however flow properties of soft clay in pipeline is not clear. This study take capillary tube tester as the prototype, instruments which is suitable for studying the flow characteristics of soft clay in pipeline is designed. Then the effects of water content, pipeline length to diameter ratio, flow velocity and stagnation time on the flow properties of soft clay in pipeline is studied. Experimental results show that: at the same pipeline length to diameter ratio, shear stress decreases while liquidity increases as water content of soft soil increases, and shear stress keeps almost the same when the water content surpasses a certain value; shear stress increases with the increase of shear rate, but level off in the end. Under the same shear rate, shear stress increases significantly with pipe length to diameter ratio increases. Greater resistance in pipeline will have to overcome when restarting the transportation of soft clay after longer stagnation time.