The Researchon Beijing Subway Tunnel Stability

With the rapid development of national economy, urban undergroundengineering, especially in the underground rail transit project has entered the phase ofthe booming, and even has become a symbol of the city’s development. More andmore cities in subway construction and in the process of subway construction causedby all kinds of safety problem more and more get people’s attention. Especiallyresearch of surrounding rock’s stability is important in the process of the wholeproject research part.For surrounding rock stability analysis at home and abroad, the main method areanalytical method, numerical analysis method, fuzzy theory and other methods thatderivative from the theory.these methods tunnel simulate the process of surroundingrock‘s development and determine all kinds of influence factor, quantitative analysisof the stability of surrounding rock. This article mainly through a project surveyprocess, qualitative analysis was carried out on the various factors which influence thestability of surrounding rock.The paper mainly based on the engineering geology survey of SZ station that isthe Beijing plans to build a subway line. Through collecting the regional geologicaldata, in situ experiment and geophysical exploration, and have done many of theearth through the indoor test of fully detailed data. Combining engineering experience,the paper on the station main body structure and the stability of the existing southinterval tunnel has carried on the analysis and evaluation,Meanwhile, the combinationof surface and underground pipelines and the surrounding buildings duringconstruction monitoring results, and it is concluded that (1) The SZ station s mainstructure appropriate uses underground station, south interval appropriate constructionby shield method;(2) For the top and side wall tunnel, the stability of surroundingrock is poor, prone to collapse, need to pay attention to the timely support; And for thebottom of the tunnel, surrounding rock bearing capacity is higher, generally can meetthe requirements of bearing capacity of natural foundation. In the last, this paper also provides the design and construction of referenceparameters for real, for later design, construction provides the correspondingsuggestions. Suggestions on the choice of foundation uses the natural foundation, bythe designer wants to separate the station excavation supporting design, suggest toprecipitation during the construction, guarantee the dry tank operation, and strengthenthe advanced prediction when excavation and excavation.