构造带围岩特性实验及流变规律分析

Characteristics experimental of surrounding rock mass in tectonic zone and its rheological law analysis

为了分析构造带围岩的力学特性及流变规律,针对金川三矿区深部岩体,进行电镜扫描、X衍射和岩石力学试验,分析地质构造对围岩的损伤机理,岩体物相成分和岩石的峰前、峰后力学强度,揭示构造围岩发生流变的内在原因;在考虑不同深度巷道围岩变形特点的基础上,采用数值模拟分别对侧压系数为0.8,1.0,1.2和1.4这4种情况下的围岩14月的流变进行计算,获得不同侧压系数下的流变曲线。应用流变力学方法建立金川已支护围岩的典型流变特征方程。研究结果表明:侧压系数越大,流变越明显,后期呈加速趋势,边帮位移可达33mm;现场监测数据和计算结果较接近,表明金川深部围岩会在支护后相当长的时间内存在明显的流变,不利于服务年限较长的巷道工程的稳定,应采取适当的加固与支护措施。

In order to analyze the mechanical characteristics and rheological law of surrounding rock mass in tectonic zone, the experiment research of electron scan, the X-ray diffraction and rock mechanical test were carried out to the deep surrounding rock mass in No.Ill Mine district in Jinchuan, Gansu Province. Damage mechanism of geological structure to surrounding rock, phase composition, pre-peak and post-peak mechanical strength of rock were analyzed, internal rheological causes of tectonic surrounding were revealed. Based on the consideration of deformation features of different deep tunnel surrounding rocks, numerical simulation was applied to calculate 14 months rheological displacements of four side pressure coefficient, which is 0.8, 1.0, 1.2 and 1.4, these rheological curves were gotten. And the type rheological characteristic equation of supported surrounding rock mass in Jinchuan was deduced by the rheological mechanical analysis method. The results show that rheological displacements increase with the increase of side pressure coefficient, the latter deformation has a accelerated tendency, and the side displacement can reach 33 mm. These theoretical results are close to the field monitoring data. Therefore, rheological deformation will sustain a long time after support for surrounding rock mass in Jinchuan Mine, which is against stability of roadway engineering for a longer service life. Some proper measures of consolidation and support should be adopted.