Study On Adverse Geological Processes Along Subway In Xuzhou City

This paper studied the adverse geological processes along the first phase of Xuzhou Urban Rail Transit Line 1,Line 2 and Line 3.Based on the geological environment background,such as meteorological and hydrological conditions,topographic and geomorphological conditions,stratigraphic lithology,regional geological characteristics,engineering geological characteristics and hydrogeological characteristics,etc.,combined with detailed field investigation,regional data,mining data,drilling data,in-situ measurement and laboratory tests,three main adverse geological processes along the metro line in Xuzhou City are comprehensively discussed,including ground subsidence of goaf;Karst ground subsidence,special types of rock and soil(sand,soft soil).Taking three kinds of adverse geological processes as the main research objects,the types,origins,distribution and scale of these adverse geological processes were identified.Predict its development trend,analyze its impact on the project and the degree of damage,and put forward treatment measures and suggestions.Through the regional geological,engineering geological and mining data,the distribution and influence of goaf along three metro lines were investigated.According to thedegree of influence range,measures and suggestions for strengthening the treatment of superstructure,avoidance of concession,grouting and monitoring were put forward.According to the possibility of occurrence of adverse geological processes of karst ground subsidence,the three metro lines are divided into three areas: base rock exposed area,non-soluble area and concealed karst area.Taking interval between Line 3 and Huaihe as examples,the development degree of karst is analyzed,the karst ground collapse is predicted and analyzed,and the location of hydrogeological skylight is more likely to produce karst collapse.Through the analysis of topography and geomorphology,the distribution and influence of sand and silt along three metro lines were investigated.The steps and methods of liquefaction discrimination of saturated silt(sand)along metro lines are discussed.Taking interval between Line 3 and Huaihe as examples,the liquefaction grade of sandy silt is ascertained by standard penetration method and static cone penetration method.At the same time,the prevention and control measures of sand and silt are put forward from six aspects: distribution range of sand and silt,precipitation,reinforcement,construction technology and monitoring.The prevention and control measures of soft soil are put forward from three aspects: ascertaining distribution range of soft soil,adopting appropriate shield machine and construction technology.The research results of this paper can provide reference for the design and safety construction of Xuzhou Metro Line 1,Line 2 and Line 3.It has certain theoretical and practical significance to provide a basis for exploring the influence of adverse geological action on underground engineering.This paper has15 figures,12tables and 68 references.