BFRP锚索框架加固强风化玄武岩高边坡动力响应规律研究

Study on Dynamic Response Law of High Weathered Basalt High Slope Strengthened by BRFP Anchor Cable Frame

锚索框架结构广泛应用于边坡支护工程中,新型高强度材料BFRP用作锚索的实际应用还较少,在组成的锚索框架对高边坡进行加固时,其在地震作用下的动力响应问题仍未定论。本文利用有限差分软件FLAC3D,以功东高速响水河某强风化玄武岩高边坡为研究对象,建立数值模型,充分考虑阻尼、边界和输入波等重要因素,对比地震作用下BFRP锚索框架设立与否不同工况下边坡动力响应变化规律。结果表明:①边坡经过锚索框架梁加固后,位移降低55.3%,呈现出"水平分层"式的向下坡方向逐渐收敛的稳定趋势,且在地震中会随着地震波做往复运动,有较强的整体性。②支护与否对坡体较深的纵断面测点加速度规律作用明显,而对靠近坡面测点的影响不明显,所以在锚固边坡有构筑物时,应尽量远离坡面坡肩。③在地震作用下,坡顶锚索轴力峰值增加最大,且锚固段轴力增加率远大于自由段,会超过二级坡锚索轴力峰值。在高烈度地区设计施工时,将上部锚索标准降低,在强震时有可能发生锚索失效。

The anchor cable frame structure is widely used in slope support engineering.The practical application of the new highstrength material BFRP as the anchor cable is still less.When the composed anchor cable frame is used to reinforce the high slope,the dynamic response problem remains undecided under the action of earthquake.In this paper,using the finite difference software FLAC3 D,a high-weathered basalt high slope of Xiangshui River is taken as the research object,a numerical model is established,considering the important factors such as damping,boundary and input wave,the dynamic response of the slope with or without BFRP anchor cable frame under different working conditions are compared.The results show that:①After the slope is strengthened by the anchor frame beam,the displacement is reduced by 55.3%,showing a stable trend of"horizontal stratification"gradual convergence in the downward slope direction,and it will reciprocate with the earthquake wave during the earthquake.Exercise has a strong integrity.②Whether the support or not has a significant effect on the acceleration law of the longitudinal section of the slope is obvious,but the influence on the measurement point near the slope is not obvious.Therefore,when there is a structure on the anchored slope,it should be as far as possible from the slope shoulder.③Under the action of earthquake,the peak force of the anchor cable of the slope top increases the most,and the increase rate of the axial force of the anchorage section is much larger than that of the free section,which will exceed the peak force of the secondary slope anchor cable.When designing and constructing in high-intensity areas,the upper anchor cable standard is lowered,and anchor cable failure may occur during strong earthquakes.