Abstract
Taking the shield tunnel project of Guangzhou Metro Line 8 from Tongdewei Station to Shangbu Station as the research background, using the research method of finite element simulation and site monitoring, this paper analyses the influence rules of shield tunneling on ground subsidence under the condition of different hard rock height ratios. The research results show that in the process of crossing different hard rock height ratio composite stratum, as the hard rock height ratio decreases, the value of ground settlement decreases and settlement tank becomes shallow. The surface subsidence in different hard rock height ratio strata is obviously different, and the maximum difference is about 8.6 mm; The influence of the hard rock height ratio on the surface longitudinal settlement is mainly reflected in the position change of the beginning and the end of the settlement. With the increase of the hard rock height ratio, the shield construction reduces the amount of the surface longitudinal settlement and its influence range; Through the research, it is found that the hard rock height ratio in the 0-0.2 and 0.5-1 is the sensitive interval, and the settlement value in these two hard rock height ratio interval varies greatly. It is necessary to pay attention to the uneven settlement of the ground surface caused by shield construction in the sensitive hard rock height ratio interval. The research results of this paper can provide reference value for similar shield construction in upper soft and lower hard composite stratum.
Highlights
Traffic construction in major cities has increasingly become prominent with rapid urbanization
The results show that with the increase of the hard rock height ratio, the location of surface deformation begins to decrease from approximately 15 m in front of the excavation face to approximately 10 m
This study mainly investigates the law of surface subsidence caused by shield tunneling in the strata with different hard rock height ratios
Summary
Traffic construction in major cities has increasingly become prominent with rapid urbanization. Deng et al [34] took Shenzhen Metro Line 2 as an engineering example, conducted a construction risk analysis under the conditions of upper-soft and lower-hard composite strata, and obtained the specific tunneling parameters through slag soil improvement and tool change with pressure; they provided valuable data for the theoretical study of shield tunneling under complex geological conditions. The present study divides the different hard rock height ratios along the upper-soft and lower-hard composite strata of the shield tunnel project of Tongdewei-Shangbu Station of Guangzhou Metro Line 8. The influence law of shield tunnel construction on ground settlement under different hard rock height ratios is obtained through statistical analysis of field settlement data and finite element numerical simulation analysis. Some suggestions are presented on the basis of the actual construction requirements, and the research results can serve as reference for similar projects
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
