滚石运动特征试验研究
Rolling tests on movement characteristics of rock blocks
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摘要: 选择坡面长度为176.4 m,坡度为39°~60°,局部坡度约为90o的边坡作为试验场地,对质量为9.592.5 kg,形状为长条状、薄片状和方形等的岩块进行256次滚石试验。在试验的基础上,分析了坡面特征对滚石停留位置的影响,坡面对滚石运动时间(到达坡底动能)和对不同形状滚石的运动特征的影响。同时,利用正交试验理论,采用滚石在坡面上运动的平均加速度作为评价指标,对影响岩块在边坡上运动的3个重要因素——滚石的质量、滚石形状和坡面状况(包括坡度以及与坡度相关的坡表覆盖层)进行了分析。结果表明:在这3个因素中,坡度及坡面状况是主要因子,其次是滚石的形状,再次是滚石质量。当滚石质量15≤m<27 kg,其形状为薄片状,坡度平均为59.6°,基岩基本裸露,滚石运动的平均加速度最大;当滚石质量9.5≤m<15 kg,其形状为长条状,坡度为39°,坡面有碎石浮土时,平均加速度最小。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指导意义。Abstract: Taking a typical slope as the test site,176.4 m in length and with slope gradient of 39~60°,nearly 90° in local,256 times rolling tests on rock blocks with the weight of 9.5 ~92.5 kg,whose shapes are strip,flaky and square,etc.,were done.Based on the results,the effects of slope features on the rock stopping position,the moving time(The kinetic energy arriving at the slope root) and the moving track of different rock block shapes were analyzed.Meanwhile,with the orthogonal test theory,the average acceleration velocity was chosen to be the evaluation index,and three important factors including the mass,the rock block shape and the slope condition(the slope gradient and overburden) were discussed.The results showed that the slope condition was the main factor,the second was the rock block shape,and the third was the rock block mass.The average acceleration was the maximum when the mass of the flaky rock block was 15≤m<27 kg and the average slope was 59.6° and the bedrock was exposed;the average acceleration is the minimum when the mass of strip rock block was 9.5≤ m<15 kg and the average slope was 39.0°,and there was some debris.The results provided the bombardment energy for the potential unstable rock mass prevention.A new feasible method for the potential unstable rock mass prevention was put forward.It would be important and helpful to the geohazard control work.