变形历程对破碎岩体水沙渗流特性影响试验研究

为研究破碎岩体变形历程对其水沙渗流特性的影响,设计了一套水沙渗透系统,在MTS816系列电液伺服岩石力学试验机上进行了配径碎岩在2种不同变形历程下的渗透试验。研究表明:破碎岩石变形历程对其水渗流特性无明显影响;破碎岩石的孔隙率在一定范围时,水沙渗流过程中,其孔隙率会由于滤沙作用而降低,导致渗透率降低;有蠕变经历的破碎岩石在水沙渗流过程中更易于过滤沙粒,滤沙量较大,而溃沙量较小;破碎岩体初始孔隙率相同时,水压梯度的增加会导致滤沙量减少,溃沙量增加。给出了一个描述破碎岩体初始孔隙率与水压梯度对滤沙量综合影响的表达式,为破碎岩体突水溃沙的风险预测评估提供指导。

Experimental study of impact of deformation history on water-sand seepage characteristics of broken rock

In order to study the impact of deformation history of broken rock on the water-sand see-page characteristics, a set of water and sand permeable system has been designed. The permeability test of distribution diameter rock fragmentation in MTS816 series of electro-hydraulic servo controlled rock mechanical test machine has been conducted under two different deformation experience. The results have shown that the broken rock deformation experience has no obvious effect on the water seepage characteristics. In addition, when the broken rock porosity is within a certain range, the porosity will reduce due to sand filtering effect and result in permeability reduction in the water and seepage process. And broken rock with creep history are easier to filter the sand in the water and seepage process. Sand filtering quality are relatively more, and sand inrush quality are less. When the initial porosity of broken rock are the same, the increase of hydraulic gradient can lead to decrease of sand filtering and increase of sand inrush. An expression to describe the comprehensive influence of the initial porosity of broken rock and hydraulic gradient on the amount of sand filter has bee given in the paper, which supports the risk prediction and assessment of water bursting and sand inrush of broken rock.