不同配比下破碎岩体变质量渗透试验研究

为了分析破碎岩体不同骨架-充填物配比条件下的变质量渗透特性,揭示煤矿陷落柱、断层等含破碎岩体地质构造的突水机理,利用自主研制的可考虑颗粒迁移作用的渗透试验系统开展了不同试样配比条件下的变质量渗透试验研究,得到了破碎岩样孔隙率、渗透率、质量流失率等参量随时间的变化规律。并在试验结果的基础上,结合陷落柱突水实例,分析了充填物颗粒迁移作用下的陷落柱突水演化规律。结果表明:1)颗粒迁移作用下破碎岩体的渗透性变化可分为3个阶段,即渗流缓变阶段、渗流突变阶段和渗流稳定阶段;2)试样充填物颗粒在水流冲蚀作用下不断迁移流失,孔隙率快速增大后趋于稳定,质量流失率先快速增加后逐渐减小;3)充填物含量对破碎岩体渗透性具有重要影响,随试样中充填物比例的增加,试样的最大质量流失率不断增加,孔隙率增幅也越大,初始渗透率和渗透率增幅均呈现先增大后减小的变化规律。

Experiment on the variable mass seepage of the broken rock under the different filling mass proportions

The present paper is inclined to conduct a seepage experiment on the broken rock mass under the effect of the particle transfer through our self-designed experiment system so as to identify and work out the porosity,permeability and mass loss rate change under the effect of the particles'transfer. As is known,though the seepage property of the broken rock mass has been paid necessary attention and some investigations have been made on the seepage characteristics of the broken rock mass,little has been done on the systematic study on the effect of the content of the filling material particles on the broken rock-mass seepage characteristics under the condition of the particles movement and disclose the mechanism of water inrush due to the geological structures. Therefore,the present paper is to devote itself to an analysis of such effect based on the water inrush mechanism by joining a water inrush accident case. Hence,as a result, we have noticed that: (1) The seepage characteristics of the broken rock mass under the filling material transfer can be classified into three stages,i. e. its slow-change stage,its mutation stage and stability stage; (2) With the filling particles transfer or movement, its porosity tends to increase sharply and then gets to be stabile, whereas its mass losing rate tends to increase first and decrease later; (3) And,then,with the increase of the filling material in the samples,the maximal mass losing rate tends to appear whilst the initial permeability and increase of permeability for rock samples may also grow first and decrease later. And,consequently,the porosity and permeability of the samples may also tend to increase with the growing rate of the mass loss,and in turn the permeability increase tends to inevitably accelerate the mass loss of the filling material, thus causing the seepage mutation and the eventual water inrush, which demonstrates that the particles transfer should account for the seepage mutation. Hence,the results of the present study can be expected to provide for experimental verification for revealing the water inrush mechanism of Karst collapse columns and faults,which helps to serve as a guide for water inrush accident prevention.