管袋坝芯砂体沿袋间接缝流失的试验研究

Experimental research on core sand losses through seam between tubes of geotube dam

采用室内模型试验与图像分析相结合的方法对单向水流作用下管袋坝芯砂体破坏并沿袋间接缝流失的相关问题进行了较为系统的研究。结合颗粒运动特点和水流水力特性变化特点阐明了单向流作用下颗粒输移模式,包括沟槽模式和全断面整体推移模式两种类型;探究了砂箱(坝芯)砂体失稳区域,试验表明砂箱内的砂体失稳区域主要集中在砂箱出口上部倒锥体区域;详尽地分析了颗粒在管路(袋间接缝)中的输移过程和沟槽的形成特点,发现颗粒运动路径主要集中在管路上表面附近区域,输移过程表明颗粒与水流之间的相互作用贯穿砂体破坏及颗粒输移的整个过程;并分析了管路颗粒输移过程中不同颗粒的空间分布特点。

Combining laboratory model tests and image analysis,a study on the damage of geotube damand sand losses through the seam between tubes under the action of unidirectional flow is illuminated inthis paper. In connection with the characteristics of particle motion and changes of hydrodynamics,the wayof sand losses is illustrated,which include two modes,the groove mode and the full-face integral movingmode. The instable region in sand box which used to simulate the dam core is explored. It is shown thatthe instable region in sand box concentrates in the inverted cone area above the sand box export. The fea-tures of particles transport in pipeline which used to simulate seam between tubes and features of thetrench formation are analyzed in detail,and it is found that the motion path of particles in the pipelineconcentrates in its surface area. The interaction between particles and water exists throughout the process ofdamage and core sand losses. Meanwhile,the spatial distribution characteristics of different particles are an-alyzed in the transport process in pipeline.