Advance Pre Reinforcement Technology In Urban Shallow Excavation Tunnel Research And Application

Twenty-first century, the peak age of urban underground construction has arrived. With the increase of China’s comprehensive national strength, and many cities are among the international metropolis, its urban modernization is speed. Best reflects the characteristics of the urban subway construction to ease the increasing traffic pressure of a large scale. To elucidate the mechanism of action and the mechanical behavior of urban shallow buried tunnel formation pre reinforcement, and applied to achieve the purpose of the project, the paper in a certain range of construction excavation Hefei Metro Line 1 for project basis, with a theoretical study, numerical simulation studies and field trials comprehensive research methods research. Specific studies are as follows:(1)systematically studied in Urban Shallow Face deformation mechanism during excavation tunnel surrounding rock deformation characteristics and influencing factors;Mechanism of Shallow Tunneling Face(2) strata reinforcement ahead of the pre-depth discussions, in order to reveal the mechanism of interaction between the mechanical stratigraphy, supporting structure and pre-reinforced structures;(3)for advanced small pipe grouting Shallow Tunneling commonly used pre-reinforcement technology, without grouting, grouting is not full and the establishment of a unified model grouting full mechanical condition;(4)using Midas GTS NX finite element software bored tunnel there, ahead of the pre-construction process without reinforcement in case of three-dimensional numerical simulation, combined with on-site monitoring with feedback thematic small duct grouting reinforcement technology pre-feasibility and practical utility.