Optimization of underground excavation in rock masses using ESO techniques

Excavation in rock masses induces complex stress redistribution around the opening. Inter alia, the stability of the opening is principally dependent on the stresses around the opening. The most influential factor attributing to the stress distribution is the geometrical shape of the opening. As such, finding the optimal shape for an underground excavation has practical significance in increasing stability and lowering support costs. This paper describes an approach to the shape optimization of underground excavation using Evolutionary Structural Optimization (ESO) techniques. Through illustrated examples, it is demonstrated that ESO method can be used to explore the excavation shapes that give optimized performance in terms of stress distribution and stability. The method is validated and compared with theoretical solutions An example of a three dimensional case is presented in comparison with a well-known application case.