大理岩圆球颗粒切向接触特性的试验研究

Experimental Research on Tangential Contact Characteristics of Marble Spherical Particles

利用岩石双轴流变试验仪,对大理岩圆球颗粒进行粒间切向接触试验,通过对试验结果的分析,揭示大理岩颗粒之间的切向接触特性。结果表明:法向力对大理岩切向破坏力的影响存在临界值,小于该临界值时,随着法向力的增大切向破坏力的增速较快;大于该临界值时,随着法向力的增大切向破坏力的增速较慢。表面摩擦系数对大理岩切向破坏力的影响与法向力大小有很大关系。当法向力较小时,表面摩擦系数会显著提高大理岩的切向破坏力,随着法向力的增大,这种影响逐渐减弱,当法向力达到法向破坏力的45%后,这种影响基本没有。球形大理岩直径越大,其切向破坏力和切向破坏位移也越大,切向刚度越小。大直径的球形大理岩所得到的试验曲线波动较大。

Rock rheological testing system is used to conduct the tangential contact tests on marble spherical particles and to reveal the contact behavior. The results show that,the influence of normal force on tangential damage force has a critical value. When the normal contact force is smaller than the value,the increasing rate of tangential contact limit force is great with the increase of normal force. When the normal contact force is bigger than the value,the increasing rate of tangential contact limit force is small with the increase of normal force. The influence of surface friction coefficient on tangential contact limit force of marble has much to do with the normal contact force. When the normal contact force is small,surface friction coefficient would significantly improve the tangential contact limit force of marble spherical particles. With the increase of the normal contact force,this effect will gradually diminish. When the normal force increases to 45 percent of normal contact limit force,this effect would basically disappear. The bigger the diameter of marble spherical particles is,the bigger the tangential contact limit force and displacement are,and the shorter the tangential stiffness is. Testing curves of big-diameter marble spherical particles fluctuate greatly.