500-Year-Old Leaning Tower of Pi

Why has the Leaning Tower of Pisa survived the strong earthquakes that have hit the region since the middle ages? This is a long-standing question a research group of 16 engineers has investigated, including a leading expert in earthquake engineering and soil-structure interaction from the University of Bristol.
The considerable height and stiffness of the Tower combined with the softness of the foundation soil, causes the vibrational characteristics of the structure to be modified substantially, in such a way that the Tower does not resonate with earthquake ground motion. This has been the key to its survival. The unique combination of these characteristics gives the Tower of Pisa the world record in DSSI effects.

为什么比萨斜塔能在自中世纪以来的多次大地震中幸存下来？这是一个研究组织长期在调查的问题，该研究组共16名工程师，包括来自布里斯托大学的地震工程学及土结构相互作用方面的一名首席专家。
塔的相当高的高度和刚度与地基土壤的柔软性相结合，导致结构的振动特性发生实质性的改变，使得塔不会与地震地面运动产生共振。这是它生存的关键。这些特征的独特结合使比萨斜塔成为DSSI效应的世界纪录。

還是沒有解釋清楚，
繼續研究吧。
不懂的地方有很多。
謙虛點好!