【摘要】 为研究软煤在塑性流动状态下的透水性能,对山西沁水盆地15#煤进行了较高围压下的应力-应变全程渗透特性试验,分析了塑性特征明显的软煤试件在进入塑性流动状态前后渗透性的变化特征。研究表明:单轴压缩强度为7.43MPa的软煤岩在6MPa围压下表现出较为明显的塑性;饱和浸水试样在相同围压下表现出更为明显的塑性流动特征;在该围压下,饱水试件在最初压缩时,随着原生裂隙的闭合,渗透率短暂降低;随着试件继续被压缩,试件产生新的裂隙,新裂隙与原生裂隙的贯通导致渗透率急剧增高;当试件进入塑性流动状态时,在围压作用下,已有裂隙压密闭和,新生裂隙的扩展和张开受到限制,软煤的渗透率将大幅度降低。更多还原

【Abstract】 In order to study the permeability of soft coal at plastic-flow state,the full stress-strain process permeability for 15# coal of Qinshui Basin,Shanxi Province with a relatively high pressure of surrounding strata was tested,and the variation characteristics of permeability of soft coal specimens with obvious plastic characteristics before and after coming into the state of plastic flow were analyzed.Studies showed that the soft coal specimen with the uniaxial compressive strength of 7.43 MPa had relatively obvious plastic characteristics at the pressure of surrounding rock of 6 MPa.Saturated and soaking specimens had more obvious plastic flow characteristics at the same pressure of surrounding rock,and under this condition of pressure of surrounding rock,specimens were compressed initially,then permeability decreased transiently,along with the closing of existing fissures.With the specimens compressed conti-nuingly,new fissures were produced and the transfixion between existing fissures and new fissures led to sharp increase of permeability.When specimens come into the state of plastic-flow,existing fissures were compressed and closed,extension and opening width of new fissures were limited by pressure of surrounding strata,the permeability of soft coal would be greatly reduced.更多还原