Using BESO method to optimize the shape and reinforcement of underground openings

In excavation design, optimizing the reinforcement and finding the optimal shape ofthe opening are two significant challenges. Both ofthese problems can be viewed as searching for the optimum distribution of material in the design domain. In structural design, topology optimization techniques have been successfully used to deal with such problems. One ofthese techniques, known as bi-directional evolutionary structural optimization (BESO), is employed here to improve the shape and reinforcement designs of underground openings. The BESO algorithm is extended to simultaneously optimize the shape of the opening and the topology of the reinforcement. The capability of the proposed approach is illustrated via numerical examples.