变质量胶结破碎岩石非Darcy流渗透特性试验研究

Experimental study of non-Darcy flow seepage properties of cemented broken rocks with mass loss

陷落柱被揭露并与地下水导通后,泥石胶结层的渗透过程伴随着质量流失,是一种演变多孔介质.利用自主研制的破碎岩石渗透系统,进行了以水泥为胶结剂的含盐胶结破碎岩石渗透试验,分析了含盐量、水泥掺入量和岩石颗粒级配3种因素对变质量胶结破碎岩石渗透特性的影响.研究结果表明:盐颗粒溶解和岩石颗粒迁移共同影响胶结破碎岩石渗透性,渗透流量随时间发生变化,先上升后下降并最终趋于稳定;含盐量越多,渗流稳定历时越长.渗透率的量级为10^(-15)~10^(-13)m^2,随着水泥掺入量的增加,试样渗透率单调减小;相同水泥掺入量下,随着Talbot幂指数n的增大,试样渗透率单调增大;随着含盐量的增加,渗透率先缓慢增大后加速增大,40g为拐点.

After the karstic collapse pillar disturbed by mining activities and connecting with groundwater,mass loss occurs in the seepage process of sparry deposit,which can be regarded as a kind of evolutive porous media.Using the self-designed experiment system for broken rocks,a series of seepage tests for cemented broken rocks with different amounts of salt were done.The effect from salt mass,cement mass and grain size distribution on the seepage properties of cemented broken rocks were analyzed systematically.The results show that：Both the dissolution of salt particles and migration of rock particles affect the seepage properties of cemented broken rocks.The water flow rate,changing over time,increases first and then decreases and finally tends to be stable.With an increase of salt mass,the time attaining to a seepage steady state increases.The permeability of cemented broken rocks with mass loss has a magnitude of 10^-15-10^-13m^2.The permeability decreases with an increase of cement mass;with same cement mass,the permeability increases with an increase of Talbot power exponent;with an increase of salt mass,the permeability increases rapidly after a slow increase,and 40 g is the inflection point.