采用模型试验方法,给出了立井回填的过程中出现填料突沉问题的相似准则.通过物理模拟,再现了泥浆夹层的形成与破坏过程,指出泥浆夹层结构的破坏导致填料突沉,进而导致悬吊管竖向荷载的突然增加;为模拟填料突沉,在试验装置底部设置气囊,以底囊排空模拟井中填料的突沉,获得了井中流体、填料级配变化条件下的悬吊管竖向荷载,并推算出原型中的竖向荷载可达40.44MN,足以拉断悬吊管;文中提出采用柔性管接头、减小管土间摩擦系数、优化填料工艺等方法,可有效控制悬吊管的竖向荷载. Using the model test method, the similarity criteria of sudden emergence of filler in the process of backfilling of vertical shaft are given, and the formation and failure process of the mud interlayer are reappeared through physical simulation. It is pointed out that the failure of the mud sandwich structure leads to the sudden rise of filler, In order to simulate the subsidence of the filler, an airbag was set up on the bottom of the test device, the submerged pocket of the filler in the well was emptied through the bottom pocket, and the hanging pipe vertical And the vertical load in the prototype can be calculated up to 40.44MN, which is enough to pull off the suspended pipe. In this paper, the method of flexible pipe joint, reducing the friction coefficient between pipe and pipe, optimizing the packing process and so on, can effectively control the suspension Tube vertical load.