The seismic hazard and risk analysis for the onshore Groningen gas field requires information about local soil properties, in particular shear-wave velocity (V_S). A fieldwork campaign was conducted at 18 surface accelerograph stations of the monitoring network. The subsurface in the region consists of unconsolidated sediments and is heterogeneous in composition and properties. A range of different methods was applied to acquire in situ V_S values to a target depth of at least 30 m. The techniques include seismic cone penetration tests (SCPT) with varying source offsets, multichannel analysis of surface waves (MASW) on Rayleigh waves with different processing approaches, microtremor array, cross-hole tomography and suspension P-S logging. The offset SCPT, cross-hole tomography and common midpoint cross-correlation (CMPcc) processing of MASW data all revealed lateral variations on length scales of several to tens of metres in this geological setting. SCPTs resulted in very detailed V_S profiles with depth, but represent point measurements in a heterogeneous environment. The MASW results represent V_S information on a larger spatial scale and smooth some of the heterogeneity encountered at the sites. The combination of MASW and SCPT proved to be a powerful and cost-effective approach in determining representative V_S profiles at the accelerograph station sites. The measured V_S profiles correspond well with the modelled profiles and they significantly enhance the ground motion model derivation. The similarity between the theoretical transfer function from the V_S profile and the observed amplification from vertical array stations is also excellent.

中文翻译：

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格罗宁根气田地面运动记录站的特征。

对于陆上赫罗纳气田的地震危险性和风险分析需要约当地土壤性质，特别是横波速度（信息V_小号）。在监视网络的18个地面加速度计站点进行了一次野外工作。该区域的地下由未固结的沉积物组成，成分和性质均不均匀。应用了一系列不同的方法来现场采集V _S至少达到30 m的目标深度。这些技术包括具有不同震源偏移的地震锥穿透测试（SCPT），采用不同处理方法的瑞利波表面波多通道分析（MASW），微震阵列，跨孔层析成像和悬浮PS测井。偏移SCPT，跨孔层析成像和MASW数据的通用中点互相关（CMPcc）处理都显示出在这种地质环境中几米到几十米的长度尺度上的横向变化。SCPT生成了具有深度的非常详细的V _S轮廓，但是代表了异构环境中的点测量。MASW结果代表V _S在更大的空间范围内提供信息，并平滑站点上遇到的某些异质性。事实证明，MASW和SCPT的组合是确定加速计站点的代表性V _S轮廓的一种强大且经济高效的方法。测得的V _S轮廓与建模轮廓非常吻合，它们显着增强了地面运动模型的推导。V _S轮廓的理论传递函数与垂直阵列站观察到的放大之间的相似性也非常好。