Design, Monitoring And Numerical Simulation Of Bracing For A Deep Excavation In Shanghai

With the great achievement of economic construction and reform and opening upin our country, the national economic has increased a lot rapidly. At the same time, allkinds of large and middle sized construction projects spring up with a fast speed. Asthe early and basic work in the area of architecture, the foundation engineering hasreached a new level in reconnaissance, designing, constructing and monitoring after alot of research by countless scientific and technical workers. The quality, safety andworking time of the engineering have been optimized a lot. But because of theextensive area, complex types of geology and different levels of constructing andtechnologies, there are still many problems in the practice of engineering especiallythe safety problem which make people live in an unfavorable life. As a result, it is thefirst thing for constructors to think about that how to construct safely andeconomically on the basic of the exist theory.In this article in view of the project of new Shanghai industrial building andancillary buildings （north parts）, according to field geological conditions, designscheme for foundation pit supporting structure and design information, the monitoringplan is developed in the process of excavation of foundation pit. In the process ofexcavation, the monitoring data shows that the retaining structure for excavation offoundation pit and surrounding soil displacement meet the safety limit of foundationpit excavation. Through the analysis for the monitoring data and finite elementcalculation and combining with the safety control requirements for excavationsupporting structure, it is concluded as follows:(1) Using MIDAS to carry out the simulation analysis for the foundationexcavation with the survey report and related parameters to determine the safety of theselected scheme;(2) Using network monitoring point to monitor the construction process andensuring the safety and orderly working of the engineering;(3) By comparison of simulated data and monitoring data to determine thepractical significance of software analysis to guide the construction and providing a reference basis for similar projects.By comparison with field monitoring data, it is turned out that excavation wouldhave enfluence on the safety of surrounding structure, but it is in a controlled area. Onthe regular, the numerical simulation results and field monitoring results keep inconsistent and it verifies the rationality of the finite element numerical simulation.