A study of building response and damage due to mining-induced ground movements

Abstract

Several methods have been developed to predict mining-induced ground movements. Some of these methods, such as the profile and influence functions, have been used successfully in a number of applications. Prediction methods, however, do not address the response of surface buildings and structures to mining-induced ground movements.

In order to study the response of a building to ground movements, a finite element model has been developed. The program named SRMP (Subsidence Response Modelling Program) is a large displacement, small strain, two dimensional finite element program. Such model is more appropriate than the commonly used small-displacement formulations and describes more accurately this particular problem because large displacements are involved in mining-induced ground movements. Four types of elements are employed in the program, namely plane, beam, transition and friction elements. Total Lagrangian (T.L.) formulation is used for plane elements and Updated Lagrangian (U.L.) formulation for beam, transition, and friction elements. The program consists of twenty six subroutines and requires about one mega-bytes of memory. It can model the slippage between foundation and subgrade. An important feature of SRMP is that it can simulate the excavation process continuously, without re-initiating the system variables and boundary conditions. Ground movement, building displacement, and stresses can be obtained, therefore, at each excavation stage.

The accuracy of the finite element model was verified through field data. The slippage between foundation and subgrade was analysed in depth. Structural deformations and stresses induced by ground movements were also studied and damage criteria in term of ground displacements were proposed. Finally, based on the SRMP analyses, appropriate measures were developed which can provide better protection to surface structures affected by excavation-induced ground movements.