扰动荷载下单孔大理岩蠕变特性试验研究

An Experimental Study on Creep Properties of Marble with Single Holes Under a Disturbance Load

以冬瓜山-790 m的地下隔离矿柱回采为工程背景,进行了室内扰动蠕变试验,分析不同轴压及扰动荷载下含孔洞大理岩的蠕变特性。试验结果表明:含孔洞大理岩的单轴蠕变先后经过蠕变衰减阶段、蠕变等速阶段和蠕变加速阶段;每次扰动岩石都会产生应变突变值,且其随应力水平的增大而增大,对于含同样大小孔洞的大理岩,扰动荷载的大小对岩石蠕变特性有重大影响,扰动荷载越大,蠕变产生的瞬时应变突变值也越大,岩石被破坏的速度越快;对于含孔洞直径越大的大理岩,扰动荷载对蠕变变形的影响也越大。最后,通过蠕变本构模型及确定Burgers扰动蠕变模型的参数等方法进行了蠕变理论分析,所得理论分析结果与试验结果具有较好的拟合度。

With the underground isolated pillar mining in the depth of-790 m of Dongguashan Mountain as the engineering background,a series of indoor turbulence creep tests have been carried out,followed by an analysis of creep properties of marble with holes under different axial compression and disturbance loads.The results show that the uniaxial creep of marble with holes undergoes successively creep decay stage,creep isokinetic stage and creep acceleration stage.The perturbation of the rock will produce the strain mutation value,which increases with the stress level.For marble of the same size,the value of the disturbance load has a great influence on the creep properties of the rock.The greater the perturbation load,the greater the instantaneous strain mutation caused by the creep,and the faster the rock will be damaged.For marble with the larger diameter of the hole,the greater the diameter is,the greater the influence of the disturbance load on the creep deformation will be.Finally,based on the statistics of the creep constitutive model and the parameters of the Burgers disturbance creep model,an analysis has been made of the creep theory,which yields results in good agreement with the experimental results.