The Forecasting Analysis Of Deep Foundation Pit Construction Deformation Based On Gray Cusp Catastrophe Theory

With the continuous development of China's economy and the rapid advance of national infrastructure and urbanization,more and more metro stations,large underground parking lots,basements of high-rise and super-high-rise buildings and shopping malls appear in cities.Therefore,deep foundation pit projects in urban construction are increasing and deep foundation pit projects are being built.There are still a series of engineering problems in design,construction,monitoring and other aspects,especially the deformation and instability of deep foundation pit in construction seriously affect the safety of Engineering construction,more and more attention has been paid by the industry.In xi'an datang international the engineering background of deep foundation pit excavation,through comparative analysis,summarizes the common deformation prediction method,by solving the mathematical state function mutation,get the differential equation of curved surface,and after summing up,it is concluded that the seven types of mutations,after comparing choice cusp type construction deformation analysis,based on the cusp mutation analysis of potential function,it is concluded that the state of the system stability in three different situations.Based on the model of deep foundation pit deformation,the influencing factors of deep foundation pit construction deformation are summarized.The calculation model of foundation pit instability was established by m-c model,and the process of instability was analyzed by FLAC strength reduction method.Through analysis of cohesive force,internal friction Angle,tensile strength and external load,the influencing factors of foundation pit instability were obtained,and the deformation and instability of datang international deep foundation pit was analyzed.The gray cusp theory is used to treat the monitoring data with equal interval,and the gray mutation model is constructed after the prediction data is generated.The state variable T is analyzed and the time difference of the foundation pit failure is obtained.The sliding surface theory is applied to explore the ultimate state of foundation pit slope instability.The deformation and instability of datang international foundation pit are predicted according to the grey cusp mutation theory.