立井回填及悬吊管竖向荷载的试验研究

Experimental Study of Shaft Filling and Vertical Loads on a Pendant Pipe

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.

Model experiments were conducted to determine the criteria associated with sudden sinking of shaft-well-filling.A mud sandwich was formed and its failure was studied.Subsidence of the upper deposit was caused by destruction of the mud sandwich,which then led to an abrupt increase in the vertical load on the pendant pipe.Subsidence of a deposit in the shaft-well was simulated by installing a bladder at the bottom of the model.Emptying the bladder simulates the sudden subsidence of a shaft-well deposit.Vertical loads on a pendant pipe under different conditions were obtained.The shaft-well fluid and the particle size of the shaft filling were changed.It was concluded that vertical loads in a prototype well would be as high as 40.44 MN,which is sufficient to break off the pendant pipe.Flexible pipe joints,reduced friction between pipe and deposits,an optimized filling process and other methods were suggested for control of the vertical load on the pipe.