| With the increasing of investment on highway of the nation, high-level highway is developing very fast, the scale of the construction of highway tunnels is becoming larger and larger, and the cost of tunnels have gained a larger share in the construction of highway more than before. How to make full use of the design theory and the practical experience, and how to use the most economic method to build safe and ' rational tunnels are the problem that concerned by the technological workers and engineers.This paper bases on the key research project of "The Research on Key Technique of Eight-Lane Tunnel", which is supported by the Guangdong Provincial Department of Communications. It takes the LongTou hill deplanate extra large-section highway tunnel as the object of study. Based on the present code of the design of the structure of tunnels, and combined with the modern optimize method, we have finished the research and production of tunnel optimization programming module in the "Tongji ShuGuang Numerical Calculation Platform". At the end of this paper, a variety of tunnel excavation methods are compared, and a series of conclusions are obtained.First of all, formulas to calculate the area of five-arch large-section tunnel and the method to confirm the lines of it is deducted. Combined with the modern optimize algorithm (Genetic Algorithms) and the present code of the design of the structure of tunnel, based on the safety of tunnels, we build a proper optimize model which takes the cost of the tunnel as object value. We also selected some key factors as optimize parameters, and actualized mathematic model in the "TongJi ShuGuang Numerical Calculation Platform".Second, LongTou Hill tunnel is taken as an example.Use mathematic model mentioned above to optimize the tunnel section to get a proper one.Then, the optimized result is compared with the present design, the insufficiency of the present design is pointed out. The whole LongTou Hill tunnel is taken as a integer. Suppose the inner-lings of the tunnel is invariable, we take the total cost of the whole tunnel as object value, optimize the whole tunnel, and then compare the optimized result with the present design, point out the insufficiency of the present design and corresponding reason.At last, based on the software platform of GeoFBA, with the use of stratum structure method, we optimize the tunnel section that is surrounded by level V rock, and then get a reasonable construction approach and excavation method. |
