基于正交设计的滚石运动特征现场试验研究

IN-SITU TEST STUDY OF CHARACTERISTICS OF ROLLING ROCK BLOCKS BASED ON ORTHOGONAL DESIGN

考虑滚石启动方式、斜坡覆盖层和植被特征、斜坡坡度、坡面长度、滚石形状和滚石质量等6个可能影响滚石运动特征的因素,按照正交设计现场滚石试验。在试验基础上,采用极差、方差和回归分析等手段,以滚石运动的加速度和滚石与坡面碰撞速度恢复系数作为评价指标,对影响滚石在斜坡上运动特征的6个因素进行分析。结果表明:影响滚石运动加速度的诸多因素中,斜坡坡度是主要因素,以下依次是滚石形状、斜坡覆盖层和植被特征、坡面长度、滚石质量和滚石启动方式;斜坡坡度、滚石形状和斜坡覆盖层及植被特征是滚石运动加速度的决定性因素;滚石运动加速度与上述决定性因素之间可用线性关系来描述。斜坡覆盖层和植被特征对滚石碰撞恢复系数起控制性作用,其他因素几平无影响;斜坡覆盖层与植被特征和碰撞恢复系数之间可用线性关系描述。所得成果为危岩体防治时冲击能量的确定提供了依据,提出危岩体整体防治的新的可行方法,对坡面地质灾害的防治有实际意义。

Site experiment of rolling rock was designed in terms of the design theory of orthogonal test, of which 6 influential factors were considered including onset style of rolling rock, feature of overburden and vegetation, gradient of slope, length of slope, shape of rolling rock and mass of rolling rock. And these 6 influential factors were analyzed with the experiment by means of range, variance and regression analysis. During the analysis, the evaluation criteria were the acceleration of rolling rock movement and the restitution coefficient of collision velocity between rolling rock and slope surface. It is shown that among so many influential factors of acceleration, the gradient of slope is the most important one, followed by shape of rolling rock, feature of overburden and vegetation, length of slope, mass of rolling rock, onset style, in turn. The gradient of slope, the shape of rolling rock and feature of overburden and vegetation are critical factors for the movement velocity of rolling rock. The movement acceleration of rolling rock has a linear correlation with those above critical factors. Among 6 influential factors, only the feature of overburden and vegetation play an important role of controlling the restitution coefficient of rolling rock, which can be expressed by a linear relation. To the prevention of potential unstable rock mass, these experiment results provide proof to determine the impact energy. New feasible method is put forward for the whole treatment of potential unstable rock mass, which has a practical significance to the prevention of slope geohazard.