碎裂岩体滑坡运动特征及近场涌浪变化规律

Motion characteristics of cataclastic rockslides and change rules of impulse waves in near-field zone

收集三峡库区48组典型岩体滑坡参数及裂隙发育情况,在遵循相似准则的基础上,结合万州河段地形资料建立浅水区碎裂岩体滑坡涌浪三维物理模型.通过多组模型试验,测定不同形状及方量的岩体滑坡水上运动特征以及滑坡淹没率对近场涌浪最大波幅的影响.结果表明:破碎后的岩体滑坡沿厚度方向产生速度梯度,使得滑坡体分层滑向水面,且滑坡最大厚度随着滑动距离的增加呈指数衰减;当滑坡淹没率小于极限淹没率时,近场涌浪最大波幅随着水深的减小而急剧降低.通过对无量纲参数的多元回归分析,建立碎裂岩体滑坡最大厚度衰减公式、浅水区滑坡淹没率经验公式以及三维涌浪近场最大波幅的预测方程.红岩子滑坡和龚家坊滑坡现场观测资料分析结果验证了方程在浅水中的有效性.

Forty-eight field data of parameters and fracture developments of typical rockslides in Three Gorges Reservoir were collected. On the basis of following similar guidelines, a three-dimensional physical model of impulse waves generated by cataclastic rockslides in shallow water area was established based on the topography data of the Wanzhou Rive section. In terms of many model tests, measure movement characteristics on the water of rockslides with different shapes and volumes, landslide submergence ratio and maximum near-field wave amplitude.The testing results show that the fractured rock mass produces a velocity gradient along the landslide thickness direction, causing the rock mass to slide layer by layer to the water. The maximum landslide thickness decreases exponentially with the increasing sliding distance. In addition, when the submergence ratio is less than the landslide limit submergence ratio, the near-field amplitudes will decrease sharply with decreasing water depth. The predictive equations were derived using a multi-variable regression analysis of the dimensionless parameters, giving the attenuation equation for the maximum landslide thickness, the empirical equation for landslide submergence ratio and the predictive equation for maximum near-field wave amplitude generated by three-dimensional shallow-water rock landslide. The applicability of predictive equations is validated by the field observation data of Hongyanzi and Gongjiafang cases.