攀枝花尖山矿区细中粒辉长岩力学特性试验研究

Experimental Study on Mechanical Properties of Fine and Medium Grain Gabbro from Jianshan Mining Area of Panzhihua City

对攀枝花钒钛磁铁矿尖山矿区的细粒和中粒辉长岩进行了单轴压缩、常规三轴压缩、抗拉强度和软化等系列岩石力学试验,研究了岩石结构(矿物颗粒大小)、水和围压等因素对岩石强度和变形特性的影响。结果表明,细粒辉长岩单轴抗压强度、弹性模量和压拉比均高于中粒辉长岩,但在三轴压缩情况下,两种岩石的峰值强度、残余强度和弹性模量差异较小;与中粒辉长岩相比,细粒辉长岩的峰值强度的黏聚力C较大,而峰值强度的内摩擦角φ较小;随着围压的增长,辉长岩峰值强度、残余强度与围压近似呈线性关系,剪切破坏角减小,平均模量E增长不明显,割线模量E50增长较显著;辉长岩的软化系数较高,在水的作用下弹性模量降低,泊松比升高。

The fine and medium grain gabbros from Jianshan mining area of Panzhihua city were tested through the rock mechanical tests, such as suniaxial compression test, conventional triaxial compression test, tensile strength test and softening test. And the influence of rock structure （ mineral grains） , water and the confining pressure on properties of strength and deformation of rocks were analyzed. The experimental results indicated that uniaxial compressive strength, elastic modulus and ratio of compression to tension of the fine grain gabbro are superior to those of medium grain gabbro. But the experimental results from triaxial compression test showed that no much difference in peak strength, residual strength and elastic modulus were observed between fine and medium grain gabbros. And C of fine grained gabbro is higher than that of medium grain gabbro but with lower ~. Peak strength and residual strength have an approximate linear relation with the confining pressure when confining pressure increased. And the slight increase in elastic modulus E, significant increase in deformation modulus E50, decrease in shear failure angle and higher softening coefficient were also observed. Under the saturation condition elastic modulus reduced and Poisson＇s ratio increased.