Optimization Of Excavation Size And Support Measures For Highway Tunnel

With the rapid development of China’s economy, more and more highway tunnel engineering, tunnel form, geology, hydrology and environment conditions of the complex and changeable, accident risk is more diverse, security issues become more prominent. At the same time, in tunnel excavation and support issues, although in accordance with the new Austrian tunneling method, but the construction in the process of excavation size, supporting measures exist unreasonable, insecurity, not questions economy. The reasonable construction excavation size and the optimization of the support means are the urgent need for the construction of the tunnel engineering.The two lane four rock highway tunnel as the research object, using finite element software ANSYS to simulate and analyze, calculate different construction design parameters of the stress and displacement of the change, rock shaft force moment, elastic resistance area, detachment, stress strain relationship, the tunnel excavation design parameters and the stability analysis and determine the size of excavation supported support were scientific and systematic research analysis. The main work is as follows:② uses the elastic plasticity theory, research and analysis of the tunnel initial stress state, after excavation of by stress state and nursing after the variation regularity of the internal forces, the establishment of model several influence factors were analyzed and established the simulation parameters selection.②through the tunnel excavation simulation and structure analysis should force displacement, determine the size of the different excavation structure stability coefficient, and then to determine a reasonable size of excavation design.② by using ANSYS finite element analysis software, to construction of accurate application of numerical simulation analysis, by D-P theory, analysis steps excavation method, different on the stage the high structural stability of excavation and the stress strain and displacement, through the analysis of tunnel resistance area, from the area, optimizing choose the reasonable excavation design;④ of on the stage excavation height of 4m excavation scheme is analyzed. According to surrounding rock stress state and resistance area, from the area, of detachment of local support, applied to a support resistance, through changing the supporting force, Poisson’s ratio, the size of the modulus of elasticity, calculation of safety factor in different situations, of surrounding rock supporting requirements of a reasonable interval analysis, and draws a conclusion that the relatively safe branch support design, improve the surrounding rock stress. Provide better design basis and technical support for the tunnel construction and ensure the safety and safety of the project.