地基土中道路交通振动的衰减特性测试分析

Analysis of the Effect of Road Traffic Load on the Vibration Attenuation Characteristics of Foundation Soils

通过对道路交通荷载下50m和80m深孔的现场振动测试,在时域和频域上分析了有车工况与无车工况下场地孔中位移随深度的衰减规律。结果表明:峰值频率随深度增大而逐步减小,在40m左右深度,峰值衰减因子接近0.2,振动衰减已很明显;与弹性半空间瑞利波的衰减规律对比发现,水平向位移衰减较弹性半空间瑞利波衰减慢,但随着深度增大,衰减因子逐渐接近弹性半空间的瑞利波衰减曲线;垂直向位移衰减因子随着深度逐步减小,且比弹性半空间瑞利波衰减得快。

This article discusses the results of field vibration testing in 50 m and 80 m deep boreholes to assess the effects of road traffic load on displacement attenuation relationships in both time and frequency domains in underground soils, focusing on traffic density. This research indicates that peak frequencies are gradually reduced with increasing depth, with peak attenuation factor close to 0.2 at depth of about 40 m and coincident decrease in vibration attenuation. When compared to the attenuation curve in an elastic Rayleigh wave half-space, horizontal displacements decrease slowly but attenuation factors gradually migrate towards the attenuation curve with increasing depth, with vertical displacement reducing at a larger rate than the attenuation curve with increasing depth.