水库库岸滑坡初始涌浪叠加的摄动方法

本文从明渠非恒定流的连续性方程和运动方程出发，用流休力学摄动法将方程展开成多项式，取其零阶和一阶进行线性化，并认为零阶为水位未摄动时的值，最后利用分离变量法，并认为其下降过程呈指数形式，得出滑坡失事点的涌浪的衰减规律，并据此进行涌浪高度的叠加。以三峡库区新滩滑坡为例，采用条分方法，用牛顿定律对条块的地面运动和水下运动进行分析，用动量定理求解条块引起的涌浪高度，然后根据衰减公式，求出滑坡失事点处叠加以后的涌浪高度。可看出，叠加方法考虑了滑坡发生过程中涌浪的动态变化，单块涌高和叠加涌高都是先增后减，与单块涌高最大值相比，叠加涌高最大值存在一定时间的滞后。

PERTURBATION METHOD OF SUPERPOSING INITIAL SURGE HEIGHT OF LANDSLIDE ALONG RESERVOIR SHORELINE

According to perturbation method in hydrodynamics,the differential equations including continuity equation and movement equation of transient flow in open channel are transformed into polynomials. The constants of polynomials are the values when water level keeps in silence,and the constants and the first differentials are selected to linearize these equations. The decay rule of surge during landslide failure site is gained by variable separation method on basis of taking exponential decay form of surge into account and the superposition of surge height is carried out. Taking Xintan landslide in the reservoir of Three-Gorges as an example,the vertical slice method and the Newton law are taken to analyze the movements on ground surface and in water,and the momentum theory is used to calculate surge height triggered by each slice. Then,in terms of decay formula,the height of surge after superposition in landslide failure site is obtained. It is concluded that superposition method considers dynamic process of the surges when landslide fails,the surge height is triggered by each slice,the surge height after superposition increases first and then decreases.