分叉型库盘变形及对特高拱坝变形性态的影响

The deformation of bifurcation reservoir basin and its influence on deformation behavior of a super-high arch dam

由弹性理论推导了特高拱坝在库水压力作用下引起的库岸边坡表面横河向水平位移计算公式;利用有限元数值仿真方法模拟了分叉河道的库盘库型,开展了库型因子对库盘基岩和大坝变形的敏感性分析。理论分析和数值计算结果表明:库水位和岸坡坡角是谷幅收缩的主要影响因素,河道分叉处到坝前距离和库水位是影响库盘变形和坝体变形的显著因素;随着高程增加,库水面以下横河向岸坡变形先向两岸方向增大,然后一直减小,直至转向河谷方向,而库水面以上岸坡一直向河谷方向变形。

The calculation formula of the transverse horizontal displacement of the bank slopes of a super-high arch dam caused by the reservoir hydraulic pressure was derived by elastic theory.Based on FEM,the reservoir type of the bifurcated channel was simulated and sensitivity analysis of the influencing factors on the reservoir basin and the dam was conducted.Theoretical analysis and numerical calculations indicate that the main influencing factors of the valley shrinkage are the reservoir water level and the bank slope angle.The distance from the river bifurcation to the dam and the reservoir water level are significant factors affecting the deformation of the reservoir basin and the dam.With the increase of elevation,the transverse deformation of the bank slope below the water surface increases on both sides of the banks and then decreases in the valley direction,while the bank slope above the water surface always deforms in the valley direction.