避共振是工程抗震设计中的重要课题,目前在边坡工程中鲜见这方面的研究。本文运用有限元法研究了边坡在双向地震作用下的共振规律及其固有频率。研究结果表明:边坡虽然有多阶固有频率,但只有前三阶固有频率处共振峰明显,其中尤以第一阶频率处的共振峰值最为突出,其他频率处则无明显共振现象;边坡在双向地震作用下的共振响应存在垂直放大和临空面放大作用;阻尼越大共振峰值越小,共振曲线越平缓;对影响边坡固有频率的主要因素进行深入研究,通过回归分析建立了边坡固有频率的经验公式,经检验该公式的计算误差较小。
One of the most important issues in seismic design is to avoid resonance,and presently there were few studies about this issue in slope engineering.In this paper,the resonance law and natural frequency of slope under bi-directional seismic were studied by Finite Element Method.The results showed that although the slope had multiple natural frequencies,only the resonance peak of first three order natural frequency is most prominent,especially the first order frequency resonance peak,and there was no obvious resonance in other frequency.Resonance response of the slope under bi-directional seismic had the action of vertical amplification and free surface amplification.The resonance peak was declining with the increasing of damping,and resonance curve was gradually gentle.The chief influential factors of natural frequency of the slope were studied deeply.The natural frequency formula of slope was established by regression analysis,of which error calculation was lower after testing.