某水电站库首右岸拉裂变形体形成机理研究

某水电站库首右岸存在一个拉裂变形体，低线施工公路从陡峭拉裂变形体山坡下部通过。低线公路开挖完成后路堑边坡发生局部塌滑，于2003年5月在其上部形成浅层滑坡体(1000多方)。结合拉裂变形体的分析和治理工作，在统计分析大量勘探资料的基础上，提出了该拉裂变形体是边坡在自重应力和构造应力的复合应力场下快速却荷引起岩体的浅表生改造，形成如荷松动岩体，后期在低线公路祠室大爆破开挖施工、下部坡体切脚和基雨的影响下形成浅层滑坡体，并逐步向上扩展的形成机理。

Forming Mechanism of the Tension-Displaced Body of a Hydropower Station Slope

There is a tension-displaced body on the right bank of a reservoir at a hydropower station. A construction road was excavated through the lower part of the precipitous hillside of the tension-displaced body. A local slump involved a volume of 1000 m3 occurred on the completion of the construction road on May 2003. On the basis of a great number of field observations, a comprehensive conceptual model is proposed, which states that the quick unloading resulted in a mass of relaxing rocks due to the self-weight and tectonic stresses. The blasting operation and cutting of the construction road generated stress concentration in the slope. The shallow landslide occurred after intense rains and the deformation of tension displaced body develops gradually upward.