Effect Of City Subway Construction On Adjacent Pipeline

With the construction of underground space and underground rail in various large and medium-sized cities, bring rail construction opportunities, meanwhile bring some subways security problems, the security problems is not only reflected in the safety of subway engineering itself, but also in the surrounding environment safety. Subway construction often have to travel through a large number of buildings and underground pipelines,the formation of cavity makes the stratum loss, leading to a certain degree of subsidence of stratum, which will necessarily affect the normal use of the underground pipeline above, if the protection measures of the underground pipeline is not in place, which will affect the normal use of the pipeline,even cause serious safety accidents. In addition, pipeline safety is directly related to the cost of the project, taking conservative scheme in order to avoid risks will lead to increasing the cost of the project. Therefore, in-depth research on the influence of the pipeline in subway construction has the very vital significance.Taking07section Muxiyuan Bridge North Station to Muxiyuan Bridge South Station in Beijing Metro Line8as the engineering background, typical pipeline is selected to studies the control standard of pipeline settlement.Using MIDAS/GTS finite element software, applying numerical simulation and combining with the measured data to analyse the subsidence law of pipeline and ground surface influenced by interval and station excavation, and then the construction control measures are optimized. On the basis of the studies above, discuss general rules of pipeline settlement, propose a safety assessment method for pipelines adjacent to subway, and summarize the control methods and measures for pipeline. The main research content and achievements of this paper are as follows:(1) Study the pipeline initial stress, pipeline and soil interaction mechanism, and sum up the type and safety control standard of pipeline.(2) Study forecasting method of the influence of subway construction on the pipeline, this method according to the settlement of ground surface to control pipeline deformation, and further propose the control reference values of pipeline settlement.(3) Comparatively analyse the numerical forecast values, the measured values and settlement control reference values. According to the analysis results, propose optimization of construction method to guide the construction.(4) In view of the two situations that pipeline parallel and vertical to the tunnel,analyzed the general rules that settlement of pipeline influenced by changes of various factors.(5) Propose the assessment method of pipeline safety risk, analyse the weight of various factors affecting pipeline safety,and summarize protection control measures of pipeline at present stage.