Dynamic Interaction Between Strata And Building Induced By Urban Tunnel Construction And Its Application

It is well-known that surrounding environment will be disturbed by strata deformation and stress relieving induced by shallow buried sub-surface excavated tunnel in urban area. Due to the complexity of urban environment, large numbers of existing buildings will be passed through and their safety and normal operation will be affected inevitably. As the construction climax of urban underground works is approaching in our country, this phenomenon is increasing and the followed problems are becoming more remarkable. Therefore it's very significant to study on the effect induced by tunnel excavation and control method for adjacent buildings.Based on domestic and foreign documents and integrated existing project experience, taking Xiamen Airport Road JC3 section tunnel passing through existing buildings complex for example, and combined theoretical analysis with numerical simulation and field survey, this paper studied systematically and deeply on basic theory and key techniques etc., consequently a series of research findings are obtained.(1) In the light of tunnel construction characteristics under existing buildings using shallow-buried method, the dynamic interaction relationship of tunnel-soil-building are proposed and strata deformation is the only medium by which tunnel excavation influences on building. Accordingly strata deformation is crux of the building safety control during tunnel construction.(2) According to the mechanism of strata deformation, the dynamic interaction between deformed & deforming strata and building foundation is emphatically studied, and then deformation characteristics and stress mechanism of existing shallow foundation are studied in different ground deformation and damage mode, and the relevant analysis model and control method are established afterwards.(3) Combined with project situ monitoring and theory study, structure deformation features and main damage modes are comprehensively analyzed, and furthermore taking brick-concrete structure and frame structure for example, the structure response law to strata deformation and its main influencing factors are demonstrated.(4) Emphasizing building deformation control standard, the concept and method of control indexes systematization are put forward, on which basic principle and determination program of control standard as well as its application characteristics are factually and thoroughly interpreted based on project practice. (5) The content and method of building safety risk assessment are put forward, and process control and process recovery using grouting uplift are then emphasized and studied deeply from theoretical analysis and engineering application.(6) According to the research findings mentioned above, and supported by risk identification, risk assessment, risk response control and risk monitoring, a systematic risk control system of shallow-buried tunnel construction under existing building is established, which proved valuable and reliable through successful engineering application.