Research on the Dynamic Construction Technology of Slurry Shields Based on the Change of Geological Conditions

As the geological conditions in shield tunnelling are becoming increasingly complex, the current practice of determining the appropriate tunnelling parameters through "trial advancing" to guide the subsequent construction can no longer meet the requirements of shield tunnelling that passes through complex geological conditions in long distances. In view of this, this paper puts forward the concept of dynamic construction technology of the slurry shield based on the analysis of geological condition changes through the characteristics of mucks excavated by slurry shields. Based on the construction example of the slurry shield tunnel of Beijing South-to-North Water Diversion Project, which passes through sandy pebble strata with interlayered clay, the performance status and faced issues during shield construction are determined from five aspects, including geological analysis, geotechnical analysis,shield tunnelling parameters analysis, other factor analysis and comprehensive analysis. By this technical concept and method it can realize the real-time and professional control of the whole shield construction process to a certain extent, which is of great significance to ensure the safety and efficiency of shield construction.