间歇式分级真空预压的模型试验

Model test on intermittent grading vacuum preloading

针对实际工程真空预压加固过程中排水板容易淤堵的问题,提出了间歇式分级真空预压的方法,即分级施加真空荷载,间歇式抽真空。经过室内模型试验,结果表明:卸载真空后,土体在自重固结作用下有新的孔隙水析出,淤堵的泥层结构在孔隙水的浸湿下受损,滤膜的渗透系数变大。此外,重新施加真空后,强大吸力的产生使土体骨架发生了破坏与重组,形成新的渗流连通通道,有助于孔隙水的排出。

Aiming at the actual engineering problem that drainage pipes are clogged easily during vacuum preloading reinforcement process,a intermittent grading vacuum preloading method is proposed,namely the vacuum load is applied in stages,and the vacuum is intermittently applied.After an indoor model test,the results show that:after the vacuum is unloaded, the soil has new pore water sedimentation under the self-weight consolidation,and the muddy layer structure is damaged under the wet water of the pore water,so the permeability coefficient of the filter becomes larger.In addition,after the vacuum is applied again,the strong suction force causes the soil skeleton to be destroyed and reorganized,forming a new seepage communication channel,which contributes to the discharge of pore water.