Development of building vulnerability functions in subsidence regions from empirical methods

Abstract

The extraction of ore and minerals by underground mining often causes ground subsidence phenomena. In urban regions, these phenomena may induce small to severe damage to buildings. To evaluate this damage, several empirical and analytical methods have been developed in different countries. However, these methods are difficult to use and compare due to differences in the number of criteria used (from 1 to 12). Furthermore, the results provided by damage evaluation may be significantly different from one method to another. The present paper develops vulnerability functions based on a concept that has been applied in other areas, such as earthquake engineering, and that appears to be a more efficient way to assess building vulnerability in undermined cities. A methodology is described for calculating vulnerability functions in subsidence zones using empirical methods. The first part of the paper focuses on existing empirical methods for damage evaluation, and selected necessary improvements or modifications are justified. The second part focuses on the development of a building typology in subsidence zones and its application in the Lorraine region, where many villages are subject to subsidence problems due to iron-ore mining. The third section describes and discusses the adopted methodology for determining vulnerability and fragility functions or curves. Finally, vulnerability functions are tested and validated with a set of three subsidences that occurred in Lorraine between 1996 and 1999.

Development of building vulnerability functions in subsidence regions from analytical methods

“…Damage distribution (a), fragility curves (b) and vulnerability curves (c) for the M4 building type, according to EMS-98. (Saeidi et al 2009) In practical terms, when developed and validated, fragility and vulnerability curves are both efficient and accurate. Vulnerability curves are used to obtain a synthetic value of the mean damage to the buildings within a given territory, for each considered building type.…”

“…The development of such a method in the field of mining subsidence represent a significant innovation, and is an efficient way to assess the possible damage that a whole city may suffer due to mining subsidence (Saeidi et al 2009). …”

“…1. Description of the main characteristics involved in mining subsidence and associated consequences (Saeidi et al 2009). a) typical profiles of the ground displacements and localisations of the compression/sagging and the traction/hogging areas.…”

An extension of analytical methods for building damage evaluation in subsidence regions to anisotropic beams

“…Figure 1. Description of the main characteristics involved in mining subsidence and associated consequences (Saeidi, Deck and Verdel, 2009). a) typical profiles of the ground displacements and localisations of the compression/sagging and the traction/hogging areas.…”

Adjusting the Influence Function Method for Subsidence Prediction

“…Secondly, these methods can be used to simultaneously assess vertical and horizontal ground movements induced by the subsidence at each point of the surface. In particular, the horizontal ground strain can be calculated everywhere and then used to assess the building damage [5,7,8,9].…”