ABSTRACT

A monumental tetrastyle canopy (four columns topped by a hollow cap overlaying a statue), built in 1948 at the centre of Kathmandu, Nepal, has suffered full collapse during the April 25, 2015 Mw7.8 earthquake. Two video camera recordings let us recover the most important movements of the structure. At a distance of 2.9 km from the monument, an accelerometric station (KATNP) recorded the motion which we used as input of a model structure made with DEM. Geometry and dimensions of main elements were mostly obtained from satellite images. Concrete and steel in columns were considered as the common practice at that time. We performed some sensitivity analyses varying the mechanical properties due to the possibility of aging alterations in concrete and steel and to incorporate uncertainties on the geometric characteristics. Albeit the response has a significant variability, results show that it is possible to reproduce well the video images, attesting the importance of video cameras to capture the dynamic performance of structures, providing insight into their behaviour and data to support numerical investigations.

摘要

1948 年在尼泊尔加德满都市中心建造的一座巨大的四柱顶篷（四根柱子，顶部是一个覆盖雕像的空心帽）在​​ 2015 年 4 月 25 日的 Mw7.8 地震中完全倒塌。两个摄像机记录让我们恢复了结构最重要的运动。在距离纪念碑 2.9 公里处，一个加速度计站 (KATNP) 记录了我们用作使用 DEM 制作的模型结构的输入的运动。主要元素的几何形状和尺寸主要来自卫星图像。混凝土和钢柱被认为是当时的普遍做法。由于混凝土和钢材老化变化的可能性，我们进行了一些敏感性分析，改变了机械性能，并纳入了几何特征的不确定性。