Research Of The Designing Method About The Supporting Structure Technology Of Highway Tunnel Single Shell Lining

The dissertation, proceeding with researching stability of surrounding rock, expounds the rationale of rock bolt,shotcrete and interact with surrounding rock when single shell lining operating, by the means of numerical simulation and in-situ test. Proposed as detailed philosophy and design cycle of the single shell lining, and ultimately for engineering applications. The paper relies on the tunnel K23+525 ~ K23+775 of Nanan to Fuling Guanchangshan secondary road worked as follows:①Obtains from the analysis of single shell lining support object, single shell lining mechanism of a comprehensive,systematic study. Based on support theory of broken zone, action mechanism of single shell lining that made up of single shotcrete and blot was researched and relevant support measure was given too.②Comparison of classification of domestic and international situation surrounding rock, rock classification proposed by the evolution of trends. Researched the yield approach degree and broken rock zone to evaluate tunnel stability, analyzed the tunnel span of broken zone by numerical simulation, support theory of broken zone was applied to rock classification of two-way road tunnel, presenting rock classification table.③Comprehensive study the limit-state design method of shotcrete single shell ling. The limit state into a permanent lining for the ultimate state I, as a permanent lining for limit state II and part of the temporary structures for the limit state III. Proposed safety factor,material factor and the components of the specific coefficients of design ideas.④Project was caparisoned to research the inner force of single shell lining that made up of multilayer shotcrete, which was compared with that of composite lining. In the first layer lining the initial support support than the composite lining in the initial support a bigger load to bear, more in line with"Code for Design of Road Tunnel"initial support under load to achieve 70% of the design requirements. The inner force produced by single shell lining was less 30% than that produced by composite one in the case of same thickness, else if produced by composite one in the case of same load, single shell lining needed less excavation,amount of lining and project cost.