空沟隔振对瑞利波传播影响的理论研究

Theoretical Study of Effect of Open Trench Vibration Isolation on Rayleigh Wave Propagation

采用理论分析方法研究土体振动在空沟底部犄角处的变截面反射与透射,以及瑞利波在空沟处的变化规律,得到瑞利波的衰减规律与空沟参数之间的关系,推导出沟外侧任意一点土体振动的计算公式。根据计算公式,对沟外侧不同位置处的土体在有无空沟条件下的振动幅值与频谱进行对比分析。结果表明:空沟深度对瑞利波的隔振效果影响明显,并且随着空沟深度的增加,空沟外侧的土体振动衰减得越多;对空沟而言,越高频率的振动衰减越明显,在同样的隔振效果条件下,随着频率减小,空沟深度应越来越深。

Based on the theoretical analysis method, the reflection and transmission of variable cross-section of soil vibration at the inner corner of the bottom of open trench and the variation law of Rayleigh wave in the open trench were studied in this paper. The relationship between Rayleigh wave attenuation law and the parameters of open trench, and a calculating formula for the soil vibration at any point outside the open trench can be obtained. According to the calculation formula, the comparative analysis for the amplitude and the frequency spectrum of soil vibration at different locations outside the open trench was carried out. The results show that the depth of the open trench has a great effect on the Rayleigh wave vibration isolation. With the increase of the depth of the open trench, the soil vibration outside the open trench is increasingly attenuated. For the open trench, the higher the frequency is, the more obvious the vibration attenuation is. Under the same vibration isolation effect, with the decrease of frequency, the depth of the open trench should be deeper and deeper.