强风化泥岩坝基运行性态及安全评价

Operational behavior and safety evaluation of highly weathered mudstone dam foundation

四川某水电站坝基主要置于白垩系强风化泥岩(又称固结粘土)之上,天然状态下抗压强度0.58 MPa,该岩体间含强膨胀岩土、石膏及芒硝形成的溶孔和溶穴。坝基采用固结灌浆、钢筋束锚固等措施。大坝已正常运行十余年,目前未发现坝基明显恶化等现象。鉴于强风化粘土岩似岩非岩,力学参数很难测定,在此类基岩上的闸坝建设经验不多,因此,总结该水电站坝基运行情况十分必要,也可为类似工程提供参考。

The dam foundation of a hydropower station in Sichuan province is mainly placed on the cretaceous highly weathered mudstone(also known as consolidated clay). The mudstone has a compressive strength of 0.58 MPa under natural condition, which contains dissolved holes and caves formed by strong expansive rock, gypsum and mirabilite. Consolidation grouting, steel beam anchoring and other measures are adopted in dam foundation treatment. The dam has been in operation for more than ten years and no obvious deterioration of dam foundation is found. Due to the similarity and difference between the highly weathered mudstone and rock, the mechanical parameters of the highly weathered mudstone are difficult to determine. Moreover, there is not much experience in dam construction on the foundation like this. Therefore, it is necessary to summarize the operation of dam foundation and provide reference for similar projects.