基覆边坡地震稳定性分析

Seismic stability analysis of slope with bedrock and overburden layer

为了分析基覆边坡即含基岩和覆盖层的边坡在地震作用力下的稳定性,采用数值模拟手段计算了边坡几何形态、地震波特征等因素对边坡稳定性的影响。计算结果显示:在加速度峰值为140cm/s2的地震作用下,60m高基覆边坡的临界坡度约为27°,即坡度达27°时边坡失稳。坡度为29°的基覆边坡其临界高度约为48m,因此用幂函数关系拟合了临界值状态下基覆边坡高度及坡度的关系,拟合公式为y=5×107x-4.132,其中x为边坡坡度,y为边坡高度。对于地震作用下对基覆边坡稳定性的影响程度而言,边坡高度的变化最敏感,其次为边坡坡度,最后为地震作用的加速度峰值。

In order to analyze the stability of base covered slope under seismic forces, the numerical simulation was used to calculate the influence of geometry of the slope, seismic wave characteristics and other factors on slope sta- bility. Calculated results show that：under action of earthquake peak acceleration of 140 cm/s2, the critical slope gradient is about 27 o for base covered slope wtih 60m high, that is, the slope is instability when the gradient of slope is more than 27 °. For base covered slope with gradient of 29 ° its critical height is about 48m, and therefore relationship between height and gradient of the base covered slope under critical condition was fitted with a power function, the fitting formula is y = 5 × 107 x -4. 132 ,where x is the slope gradient,y is the slope height. For the stability of base covered slope under earthatake, the most sensitive influencing factor is slope height, followed by slope gradient, and finally the peak acceleration of the earthquake.