Abstract:
Underground utility tunnel is an important way for urban underground space development. In order to optimize the structure of the utility tunnel, this paper proposes a structural optimization design method based on the response surface model. Based on the analysis results of the finite element model, the appropriate structural mechanics response is selected as the control parameter. Using Latin hypercube sampling (LHS) and optimized Latin hypercube sampling methods, the response surface model between design parameters and structural mechanics response has been established, and the accuracy of different response surfaces models has been evaluated. The results show that the optimized Latin hypercube with 4 times of the minimum number of sample points which has been used to establish a response surface model can balance efficiency and accuracy. Based on the response surface model, an optimization model considering various constraints such as reinforcement is established. The optimization model is solved by nonlinear programming and genetic algorithm. The results show that the solution method has less influence on the optimization result and the model has good robustness. After optimization, the cost of the structure was reduced by 27.58%, and the bending moment of the control section was reduced by 45.10%, 45.72%, and 24.40% respectively. The optimized model was analyzed by the finite element method, and the results showed that the error between the response surface model and the finite element analysis was less than 15%. It is reasonable and effective to use the response surface model to replace the finite element analysis process.