Analysis Of Anti-heave Stability Of Excavation In Soft Soil

Chinese urbanization process has further accelerated.The rapid development of the city and the urgent needs of infrastructure have presented new challenges to the difficulty of design and construction.With the widespread launch of similar new infrastructures,the construction of foundation pits has become more complex with previous characteristics of deep and large.They are also posed with higher standards from economy and safety perspectives.When conducting analysis for foundation pit deformation and stability,anti-heave stability is a major factor affecting the safety of foundation pits,and it is also a parameter condition that requires strict verification in designing stage.However,the current design method is too conservative and the theoretical forming time is relatively early,which is not very reasonable for the increasingly refined design and construction.Therefore,research on the deformation mechanism of the foundation pit heave and the improvement of the stability analysis method against the heave appear rather necessary.Based on a foundation pit project in Nanjing,this study includes literature investigation,theoretical research,field data analysis,and finite element numerical simulation to determine the mechanism of foundation pit heave deformation,factors affecting the stability of anti-heave stability,and the stability of anti-heave The analysis method and its improvement and the evaluation of the stability of the long and narrow foundation pit against heave are studied and discussed in these five aspects.The main tasks are:1)Using field monitoring data of the case foundation pit,the characteristics of the foundation pit heave and deformation are analyzed.2)Midas/GTS NX finite element software is used to simulate the case foundation pit,revealing the occurrence of heave deformation and other deformations laws.3)Stability analysis methods in the current codes are compared and analyzed,combined with the existing data of the case foundation pit,with a trial foundation pit being established.Starting from the trial foundation pit,the effect of each parameter on the calculation result of the safety factor is compared and analyzed.4)For narrow and long foundation pits,finite element models of foundation pits with different widths have been established,which intuitively demonstrates the feature of smaller heave deformation of narrow foundation pits.Based on the existing standard methods,two types of analysis model of anti-heave stability of foundation pit are presented.This paper has a strong reference significance for studying the stability analysis of foundation pits in soft soil areas,and it has certain using value for design and construction of foundation pits.