M. Yinfei Cai soutiendra sa thèse intitulée "Simulation of underground mining subsidence and its induced damages on buildings »
le vendredi 13 mars prochain à 9h30
Amphi 100 à Mines Nancy,
Le jury sera composé de :
Alec M. MARSHALL –University of Nottingham – UK - Rapporteur
José M.GALERA – Universidad Politécnica de Madrid – Spain - Rapporteur
Marwan AL-HEIB – INERIS– France - Examinateur
Hussein MROUEH – Université Lille 1 – France - Examinateur
Thierry VERDEL – Université de Lorraine – France - Directeur de thèse
Olivier DECK – Université de Lorraine – France - Co-directeur de thèse
Karim BENSLIMANE - BRGM - France - Invité
La soutenance se déroulera en anglais et sera retransmise en direct puis en différé sur videos.uni-lorraine.fr
Abstract :
The objective of this thesis is to improve the methods of subsidence computation and building damage evaluation, and to develop some tools based on these methods to study the mining subsidence and building damage cases in Lorraine.
By investigating the topography influence on subsidence under simplified mining conditions, by using numerical models with varying mining depths and ground surface angles, a new influence function method, which is based on a probability density function of a skew normal distribution, to simulate the element subsidence, is firstly developed and can be used to compute the mining subsidence caused by the excavation under non-flat surface. Several numerical simulations and two field subsidence cases were studied and showed that compared to the original influence function method, the improved method better simulates subsidence, especially in terms of horizontal displacements.
Then, plane framed structural models are chosen to study the mechanical behaviors of 3D buildings. For each building, two plane models located in the vertical sections passing through the principle inertia axes of the building’s projective polygon are considered. Their geometry and mechanical characteristics are chosen according to the construction type and used materials of the building under consideration. Then, by using the matrix displacement method with some modifications, the internal forces and displacements over the structure can be computed. The achieved internal forces can then be compared to damage grade criteria to determine the building’s damage extent.
Finally, by using the improved methods of subsidence computation and building damage evaluation, a real case application is performed in Joeuf city (France). The subsidence is computed and applied to the defined structural models as support displacements, and then the damage extents of the buildings in Joeuf are predicted. In the worst case, if all six possible mining zones in two layers under Joeuf city are considered collapsed, the maximum vertical subsidence and horizontal displacement are approximately equal to 2 m and 1 m, respectively, and 37% of the buildings in the city are in high danger