利用自行研制的裂隙-管道介质物理模型进行多组试验，探究落水洞对介质排水过程的影响。对裂隙-管道介质按照介质空隙结构特点进行分区，引入反映介质排水过程中水体排泄快慢的单位时间排水量，进而得到对应不同介质分区和介质整体的四个单位时间排水量。利用单位时间排水量分析九种落水洞横截面积对裂隙-管道介质排水过程的影响。结果表明：落水洞横截面积的增大对裂隙-管道介质结构的影响为增大其储水空间和导水空间；落水洞横截面积的增大会加快裂隙-管道介质的排水过程，排水过程对落水洞横截面积增大的响应在横截面积的增大量达到某一阈值后才会发生，该阈值和介质空隙结构有关；排水过程的三个不同阶段的阈值不同，末期的阈值小于初期、中期的阈值。

The effects of the sinkhole size on the drainage process of fissure-conduit media were analyzed using the self-designed physical model of fissure-conduit media. The media was divided into three regions according to the structural characteristics of the media voids. Water discharge per unit time, a concept that represents the speed of water drainage, was introduced. The water discharges per unit time of the three regions and of the media as a whole were calculated. The water discharge per unit time was used to analyze the effects of nine different sinkhole sizes on the drainage process of the fissure-conduit media. The results showed that as the cross-sectional area of the sinkhole increased, the water storage volume and water conducting volume of the media were enlarged, and the drainage speed was enhanced. It was only when the cross-sectional area reached a certain threshold that the drainage process would respond to the increase in the cross-sectional area of the sinkhole. This threshold depended on the structure of the media voids. The three different stages of the drainage process had different thresholds. The threshold in the final stage was smaller than that in the initial or middle stage.

国家自然科学基金（41172203;41572210)