中文摘要：

通过两种不同渗流速度的室内试验系列,采用在每个系列中分别向土柱中注入13次约392 mL颗粒悬浮液的方法,研究了注入次数和粒径对多孔介质中颗粒迁移特性的影响。结果表明,注入次数、颗粒粒径以及渗流速度对颗粒迁移特性有重要影响：在稳定速度的渗流作用下,注入颗粒的迁移特性曲线呈现类似于＂正态分布＂的规律,下降段持续时间大于上升段持续时间;渗流速度较小时,随着注入次数增加,颗粒浓度峰值逐渐增大;渗流速度较大时,颗粒浓度峰值几乎不随注入次数变化。中值粒径为3.40μm的颗粒随深度增加,沉积颗粒的质量比逐渐减小;中值粒径为5.10μm的颗粒在0.085 cm/s速度渗流作用后的沉积颗粒质量比要明显大于0.170 cm/s速度渗流作用后的沉积颗粒质量比。渗流速度较小时,颗粒粒径越大所受的重力越大,相应的运动速度也越大;渗流速度较大时,水动力是影响颗粒迁移速度的主要因素。粒径越大的颗粒所受的筛滤作用也越大,相应的沉积量也越多。

英文摘要：

Experiments were conducted to investigate the effect of injection times and particle sizes on particle transport in porous media.Two experimental series were performed under two different flow velocities.Injections of 392 mL particle suspensions into the porous media were repeated 13 times for each experimental series.The study reveal that injection times,particle sizes and seepage velocities have great impact on the characteristics of particle transport.Under steady seepage velocity,the transport curves of the injected particles have a normal distribution and the pore volume corresponding to the descent portion of the curve is larger than the value of ascent portion.Besides,the peak concentrations increase with injection times for low flow velocity conditions.However,peak concentrations hardly vary with the injection times for high flow velocity conditions.The amount of the deposited particles decreases with increased depth for particles of 3.40 μm median diameter.The quality ratio of the deposited particles under 0.085 cm/s flow is greater than those under 0.170 cm/s flow.When the seepage flow rate is low,the effect of gravity increases for larger size particles,and the corresponding particle transport velocity is also higher.However,when the seepage flow rate is high,particle transport velocity is mainly controlled by hydrodynamic forces.The screen effect on particle deposition is more obvious for particles of larger grain sizes,resulting in a higher deposition rate.