滑坡碎屑化运动物理模型相似材料特性研究

A study of the similar material characteristics of fragmenting rock mass physical model

高速远程滑坡物理模型试验中,岩石相似材料的选择是模型试验成功的关键,然而目前滑坡相似材料强度高、难以在缩尺试验中模拟滑坡破碎过程。以重晶石、石英砂为骨料,石膏为胶结剂,羧甲基纤维素钠、甘油、水作为辅助材料,进行可破碎岩石相似材料的配比试验。采用控制变量法研究重晶石与石英砂比例(重石比)、骨料与胶结物比例(骨胶比)、羧甲基纤维素钠含量、拌合水量、甘油含量对相似材料物理力学性质的影响。试验结果表明:所有配比情况下各相似材料物理力学参数的范围分别为单轴抗压强度为0.12~1.47 MPa,弹性模量为25.51~148.12 MPa,黏聚力为1.63~87.39 kPa,内摩擦角为22.70°~35.89°,脆性指标主要分布在0.033~0.145之间;重石比主要控制岩石相似材料的内摩擦角;骨胶比减小,对应的黏聚力和内摩擦角先增大后减小;羧甲基纤维素钠对材料的单轴抗压强度、弹性模量、黏聚力等材料的力学特性以及材料的脆性指标影响均比较大,其中对单轴抗压强度的影响最大。因此,控制羧甲基纤维素钠和拌合水量的含量,并合理调节重石比与骨胶比,在相似比约为1∶600的试验尺度下,最终确定了适用于高速远程滑坡碎屑化过程模拟的低强度高脆性岩石相似材料的配比区间。

Similar materials in the physical model test of avalanche are the key to the success of the model test.However,the strength of similar materials is high at present,it is difficult to be fractured within the scope of the experiment.The materials can reproduce the clastic process of landslide in the scale model experiment.Thus,we choose five raw materials to formulate similar materials.The five raw materials are barite,quartz sand,gypsum,sodium carboxymethyl cellulose,glycerin and water content.Five influencing factors are analyzed,including the ratio of barite to quartz sand,the ratio of aggregate to gypsum,contents of sodium carboxymethyl cellulose and glycerin,and water content.The aggregate consists of barite and quartz sand.The results show that(1)in all the experiments,the uniaxial compressive strength ranges from 0.12 to 1.47 MPa,the elastic modulus,from 25.51 to 148.12 MPa,the cohesion,from 1.63 kPa to 87.39 kPa,the angle of internal friction,from 22.70°to 35.89°,and the brittleness index,from 0.033 to 0.145.(2)The ratio of barite to quartz sand has the great effect on the angle of internal friction.(3)With the decrease in the ratio of aggregate and cement,the cohesion first increases and then decreases.Sodium carboxymethyl cellulose has the greatest influence on the parameters of the similar materials,especially the uniaxial compressive strength.Therefore,it is important to control the sodium carboxymethyl cellulose,glycerin and water content and adjust the mass ratio of barite to quartz sand and the mass ratio of aggregate and cement.The obtained similar materials can be used to simulate the clastic process of avalanche when the similarity ratio is approximately 1∶600.