Monitoring Measurement And Stability Research On Neighborhood Roadtunnel Inweak Surrounding Rock

The Midwest of China is a mountainous area, which has complicated andvariable geological conditions and soft rocks can often be found. In this area, highwaytunnels building were restricted by geological and topographical conditions. Withbetter terrain adaptability and constructing simplicity than arch tunnel, theneighborhood tunnel as a particular form and structure has often been used in project.Therefore, how to ensure the stability of neighborhood tunnel construction in weakrock conditions and prevent from the emergence of large deformation and big collapseaccidents turns out to be a serious issue.The theory of this paper is based on analysis of tunnel’s surrounding rockstability, and the methods are the monitoring and measurement of the tunnelconstruction process, the numerical simulation research, and so on. By analyzing onthe case study of Fenshuiling tunnel of the highway from Gucheng to Zhuxi, thispaper discusses about how to use the monitoring and measurement technology and tokeep the stability of neighborhood tunnel in weak rock condition. The main purposesand the results of this paper are as follows:(1) To obtain the detailed engineering data of Fenshuiling tunnel through surveydata, construction drawing, and field research.(2) To introduce the monitoring measurement program of Fenshuiling tunnel anddescribing the method for determining the data collected; Sum up the finaldeformation data of Fenshuiling tunnel’s vault settlement and the surrounding in allsections’ construction period from the beginning to the end; and finally, identify itsroughly corresponds relationship between rocks.(3) To analyze the internal and external factors affecting the stability ofsurrounding rock, combined with all sections’ field monitoring data as well as arepresentative section analysis of monitoring data, through the characteristic analysisof various types’ rock deformation, to forecast the time of initial support to stabilize,and to provide a reasonable basis for the time of secondary lining construction.(4) To use finite element analysis software to simulate the excavation process ofⅣ and Ⅴ grade rock in Fenshuiling tunnel, and analyze the deformation of theexcavation process and the initial force of tunnel supporting structure. Since theresulting of displacement deformation and monitoring measurement data areconsistent, the initial supporting and grouting measures of middle pillar for the overallstability of the tunnel rock can be considered as reasonable and effective.