岩石裂隙的法向蠕变及渗流的影响

法向蠕变是岩石裂隙的重要力学性质之一．通过分析岩石裂隙法向蠕变机理、进行干燥及渗流情况下岩石裂隙法向蠕变试验，探讨了岩石裂隙的法向蠕变及渗流的影响．研究表明，对于粗糙岩石裂隙来说，瞬时有效应力总等于裂隙凸起的压缩强度，因而初始法向蠕变明显，而后随接触面增加，蠕变速率逐渐降低；渗流过程中，岩石裂隙法向蠕变更加明显，且初次加栽应力水平下岩石裂隙法向蠕变远大于后续加载应力水平；岩石裂隙法向蠕变不能决定岩石裂隙渗流能力的降低，水力冲蚀作用明显时，可能产生裂隙渗流能力随裂隙法向压缩而增大的情况；岩石裂隙的蠕变闭合与岩石裂隙面粗糙度有关，粗糙度越大，岩石裂隙蠕变闭合量越大．研究结果对岩石裂隙法向蠕变的数值模拟及工程实践有一定参考价值．

Normal creep deformation law of rock fracture and the influence of seepage

The normal creep deformation of rock fracture is one of the important rock mechanical properties.The paper discusses the normal creep characteristics of rock fracture and the influence of seepage to it by analyzing the normal creep mechanism of rock fracture and by conducting normal creep tests for dry rock fracture and the rock fracture under seepage conditions respectively.The results show that the instantaneous effective stress is always equal to the compression strength of asperity of rough rock fracture,thus the initial normal creep deformation is obvious,and then creep rate reduce gradually with increment of contact area;normal creep deformation will become more obvious while water is flowing through the rock fracture.Moreover,that the normal creep amount of rock fracture under first loading stress is larger than those of following loading stresses.However,the increase of normal creep deformation of rock fracture can not determine its reduction of seepage capacity,and the seepage capacity of rock fracture can even increase with its normal creep closure when there is enough hydraulic flushing ability.The creep closure of rock fracture has a close relation with roughness of rock fracture surface,and the greater the roughness is,the greater the creep amount is.The results have a certain reference value for numerical simulation and engineering practice related to the normal creep deformation of rock fracture.