The Arch Dam Design Optimization Of Baijiang River Hydropower Station

In recent years, with the rapid development in the hydraulic damming technology, the design optimization and the computer technology, arch dam optimization, as one of the most important methods of saving investment in engineering project, has become a buzzword in the industry. Among many of water conservancy projects, Baijiang River Hydropower Station, which is a pivotal node of electric power development plan in Jingyu County, is in urgent need of optimization after the preliminary design stage.The algorithm comparison in the first place, for the Baijiang River Hydropower Station Arch Dam optimization chooses the appropriate optimization algorithm. An algorithms called MIGA-NLPQL that combined with Multi-Island Genetic Algorithm(MIGA) and Nonlinear Programming Quadratic Line search(NLPQL), which is compared the precision, convergence rate, initial value sensitivity and local characteristics in solving the problem of non-convex function respectively, is selected for the optimization tasks for Baijiang River Hydropower Station Arch Dam,To achieve this goal, a preliminary optimization is accomplished using MIGA in the first stage of MIGA-NLPQL. In the second phase MIGA-NLPQL, NLPQL is utilized by using the optimal initial swarm of the first phase results. Compared with the traditional algorithm, MIGA-NLPQL can obtain the high accuracy global optimal solution with the least calculation.Then, the objective function and the constraint are decided. In this optimization task, the goal is to the volume of the dam, the radius of the center line of horizontal arch ring, the bottom width of the crown cantilever and the characteristic value of geometric parameters that in the upstream face of the crown cantilever are chosen as the variables, the stress constraint, stability constraints and the geometric constraints are considered. Considering the great air temperature yearly variation amplitude in the dam site of Baijiang River Hydropower Station Arch Dam, the heat preservation measures that spray 5 cm thick of polyurethane foam plastics on the both upstream and downstream dam faces is adopted, and the condition of insulation is taken into account in the analysis of temperature stress.At last, a program that integrates ISIGHT, CATIA and ABAQUS is mainly developed. The way to give full play to advantages of the parameterized modeling of CATIA, the finite element nonlinear analysis of ABAQUS and the integrated optimization of ISIGHT, and the finite element equivalent stress is calculated with MATLA.Compared with the conventional dam design scheme, under the precondition of all constraints, in terms of the optimized dam shape features, the crest width is unchanged. The bottom width of the crown cantilever is reduced by 3m. Vault central angle is increased by 8.76 degrees. And a thinner dam type with the lower degree of overhang and the 22.6% off thickness-height ratio are produced. Moreover, the optimization task has a positive economic effect with 20.5% off dam volume.