Environmental vibrations induced by human activities such as traffic, construction or industrial manufacturing can cause disturbance among residents or to vibration sensitive equipment in buildings. In Sweden, geological formations of soft clay overlying a stiff bedrock are soil conditions prone to ground vibrations that are encountered both in urban areas and along parts of the national railway network. This paper presents an extensive investigation of the small-strain soil properties for the prediction of environmental ground vibrations in a shallow clay where the bedrock is situated at 7.5 m depth. The small-strain properties are estimated using available empirical correlations, bender elements, seismic cone penetration tests, seismic refraction and inversion of surface wave dispersion and attenuation curves. The results are synthesised into a dynamic layered soil model which is validated by measurements at the soil's surface at source-receiver distances up to 90 m in the frequency range 1–80 Hz. Analyses of uncertainties in the estimated values of wave speeds and material damping are performed by model investigations, indicating that surface wave tests overestimate the damping compared to bender element tests. The properties of the topmost unsaturated part of the soil is found to have a significant influence on the response at large distances, caused by critically refracted P-waves resonating in the top layer.

由交通、建筑或工业制造等人类活动引起的环境振动会对居民或建筑物中的振动敏感设备造成干扰。在瑞典，覆盖在坚硬基岩上的软粘土地质构造是容易发生地面振动的土壤条件，在城市地区和部分国家铁路网络沿线都会遇到。本文对基岩位于 7.5 m 深的浅层粘土中用于预测环境地面振动的小应变土壤特性进行了广泛的研究。使用可用的经验相关性、弯曲元件、地震锥穿透测试、地震折射和表面波色散和衰减曲线的反演来估计小应变特性。结果被综合到一个动态分层土壤模型中，该模型通过在 1-80 Hz 频率范围内源-接收器距离达 90 m 的土壤表面测量得到验证。通过模型研究对波速和材料阻尼估计值的不确定性进行分析，表明与弯曲元件测试相比，表面波测试高估了阻尼。发现土壤最顶层非饱和部分的特性对远距离响应有显着影响，这是由在顶层共振的临界折射 P 波引起的。通过模型研究对波速和材料阻尼估计值的不确定性进行分析，表明与弯曲元件测试相比，表面波测试高估了阻尼。发现土壤最顶层非饱和部分的特性对远距离响应有显着影响，这是由在顶层共振的临界折射 P 波引起的。通过模型研究对波速和材料阻尼估计值的不确定性进行分析，表明与弯曲元件测试相比，表面波测试高估了阻尼。发现土壤最顶层非饱和部分的特性对远距离响应有显着影响，这是由在顶层共振的临界折射 P 波引起的。