Research On Mechanical Effect Of Underground Tunnel Structure Under Additional Load Conditions And Its Reliability Analysis

As the construction of traffic infrastructure especially high level road continuouslydevelops in our country, more and more tunnel constructions come out now. For a longtime, there have always been serious defects and deficiencies on mechanical effectevaluation and structure parameters analysis for existing tunnel structures. The result isthat driving safety, driving comfort, normal use and reasonable evaluation of undergroundtunnels and other lifeline engineering are badly affected. So how to reasonably analyzemechanical effect, structure parameters optimization and engineering reliability has veryimportant theoretical significance and practical engineering value for engineering practiceof tunnel structures.Based on the lifeline engineering of Qing-Qin water delivery tunnels under theQin-Fu fast road, this paper has researched the mechanical effect of tunnel structure,optimized tunnel structure parameters, and has also analyzed the reliability of tunnelstructure by the combination of scene investigation, theoretical analysis and numericalsimulation.Firstly, based on the tunnel engineering under Qin-Fu fast road, reasonableengineering mechanics and numerical calculation models have been built by using theFLAC^3D program, and the mechanical effect that comes out in tunnel structure and wallrock by the underground method and the open-pit method has been analyzed. Thecharacteristics of deformation field, plastic disruption field, stress field changes in tunnelstructure and wall rock have been revealed, and theoretical basis has been provided forengineering design and construction. Secondly, based on scene reconnaissance data, andindoor and outdoor experiment data, engineering mechanics models have been reasonablygeneralized. Tunnel structure parameters under additional load have been calculated andoptimized using Li Zheng tunnel lining software. Finally, based on the interaction relationbetween tunnel structure and wall rock, and the limit equilibrium theory, the reliabilitylimit equilibrium equation of tunnel structure has been created, and tunnel structurereliability has been analyzed by an engineering example.