Study On The Construction Technology Of Jinzhai Extra Large Tunnel

Since the development of the railway construction recently in China is very fast, PDL high speed railway is newly applied in China. Because the requirements on the straightness and longitude cross-section of high speed railway is very high, the number of tunnels is more and more, and the ratio of tunnel length to the total length is more and more. At present, we have less experience on building the high speed PDL, especial less experience on building the PDL tunnel projects, so, how to handle the differences of PDL tunnel and normal tunnel, what are the key technology of PDL tunnel construction, and by which way to design and construct PDL tunnel are the main problems we should face to at this moment.The tunnel projects are greatly controlled by the geology and water condition. They are greatly influenced by the location and have differences in many ways, especially the extra large tunnel, they have greater differences. Jinzhai tunnel is one of the extra large PDL tunnels we construct in China. It has the features of big cross section, high standard, tense time schedule and hard stones and so on.This paper proposes the reasonable construction method, construction techniques and safety techniques according to the geology and water condition research of Jinzhai tunnel, the verification to the organization construction scheme, the analysis of geology scourage, the study on the control policy, the on-site experiment on the parameters of tunnel smooth blasting, the study on the on-site air and ballast, the contains of tested air, and the release law of harmful gas.The study results mainly contain:(1) The features and key technical issues of the extra large PDL tunnel in petrosilex area;(2) Proposing the construction measures of Jinzhai Tunnel;(3) Concluding the key technical issues and main technical measures of Jinzhai tunnel construction;(4) Explaining the discipline of geology scourge in Jinzhai tuneel' construction and concluding the prevention technology;This paper researches on the design, construction and scourge prevention of Jinzhai extra large tunnel in Hewu PDL railway; it analysis and concludes on the extra large tunnel projects in petroliex area; it also quests for the technique of the mechanical construction, fast excavating, long distance air supply and geology scourge prevention. The research results have reference value for the design and construction of extra large tunnel.