Structural failure due to local soil subsidence is a severe issue in the urban environment, particularly in cities located on thick sediments. We present such a case from Mexico City, where the near-surface soil characteristics beneath a subsided building were examined using 3D ambient noise tomography. We acquired data using dense arrays of 4.5 Hz vertical geophones placed around the building in two geometries. We performed cross-correlation analyses for 12 central frequencies in the range of 4–12 Hz to built tomographic images of surface wave group velocity. The results indicated a low-velocity layer (~ 120 m/s) for the first 10 m depth which we interpret as the typical clay layer of the Lake Zone of the city. Below, a more complex stiff layer (~ 500 m/s) appeared with significant lateral variations. In another independent analysis of HVSR, we observed that the site period varied between 0.4 and 0.55 s, which further signify the complexity of the subsurface. Thus, the conspicuous structural failure was due to the lack of stiffness of the shallow foundation, which subjected to differential motions between consistent materials from the foot of Chapultepec hill, and the soft lacustrine clays of the Lake Zone. As shown in this case, the seismic response variations in short distances, and short periods, for near-source events could be of great importance as demonstrated in Mexico City during the recent Puebla-Morelos Earthquake (M7.1) of September 19th, 2017.

由于局部土壤沉降而导致的结构破坏在城市环境中是一个严重的问题，特别是在沉积物较厚的城市。我们从墨西哥城提出了这样一个案例，该案例使用3D环境噪声层析成像技术检查了塌陷建筑物下方的近地表土壤特征。我们使用在建筑物周围以两个几何形状放置的4.5 Hz垂直地震检波器的密集阵列来获取数据。我们对4-12 Hz范围内的12个中心频率进行了互相关分析，以建立表面波群速度的断层图像。结果表明，在前10 m的深度中存在一个低速层（〜120 m / s），我们将其解释为该城市湖区的典型黏土层。在下方，出现了一个更复杂的刚性层（〜500 m / s），具有明显的横向变化。在对HVSR的另一项独立分析中，我们观察到，站点周期在0.4到0.55 s之间变化，这进一步表明了地下的复杂性。因此，明显的结构破坏是由于浅层地基缺乏刚度造成的，而浅层地基受到了Chapultepec丘陵脚下的稳定材料与湖区软的湖相粘土之间的差异运动的影响。如本例所示，如2017年9月19日的最近的普埃布拉-莫雷洛斯地震（M7.1）在墨西哥城所证明的，近源事件在短距离和短时间内的地震响应变化可能非常重要。 。在查普尔特佩克山脚下的稳定物质与湖区的软湖相粘土之间经受了不同的运动。如本例所示，如2017年9月19日的最近的普埃布拉-莫雷洛斯地震（M7.1）在墨西哥城所证明的，近源事件在短距离和短时间内的地震响应变化可能非常重要。 。在查普尔特佩克山脚下的稳定物质与湖区的软湖相粘土之间经受了不同的运动。如本例所示，如2017年9月19日的最近的普埃布拉-莫雷洛斯地震（M7.1）在墨西哥城所证明的，近源事件在短距离和短时间内的地震响应变化可能非常重要。 。