Research On Safety Monitoring And Prediction Of Ultra-large And Ultra-deep Foundation Pits In Large Water Purification Plant

The excavation of the foundation pit destroys the original structure of the strata,causing the stress difference between the soil inside and outside the foundation pit,which makes the deformation occur around the foundation pit.However,as the environment of the foundation pit site is getting more and more complicated,there are many factors affecting the foundation pit deformation,so it is easy to occur accidents.In the water-rich round gravel stratum,the construction of foundation pit is very difficult,and there are some construction problems such as stuck drilling and collapsed holes.n order to clarify the deformation law,risk level of the pit and future deformation of a large water quality purification plant’s oversized super-deep pit,the pit is monitored on site.This paper takes the foundation pit project of a large water quality plant as the background,according to the monitoring data,the research on the deformation of the super deep foundation pit project and the deformation law of the surrounding environment is carried out,the safety risk level of the foundation pit is studied using the entropy weight-fuzzy comprehensive evaluation method and the two prediction models of GM(1,1)model and LSTM model are preferred,and the model with the better prediction effect is selected for the foundation pit deformation,the early warning evaluation of future deformation of the foundation pit based on the prediction results for safety risk.The main research of this paper includes the following points:(1)Through the analysis of the actual monitoring data of each monitoring item of the pit,the deformation of the pit body and the surrounding environment of the pit during the construction of the pit is obtained.For the parts or protruding points with high frequency of change in the monitoring data during the monitoring process of the foundation pit,the parts and protruding points with high frequency of change will be analyzed in depth and the reasons for their changes will be obtained by combining the actual working conditions and the foundation pit itself and external factors.(2)The entropy entropy fuzzy comprehensive evaluation method formed by the combination of entropy-entropy method and fuzzy comprehensive evaluation method is used to evaluate the safety risk of the foundation pit,and the risk level of the foundation pit body,surrounding environment and the foundation pit as a whole is determined in a qualitative and quantitative evaluation.Through the safety evaluation of the foundation pit project of this water purification plant,the calculation results are in line with the actual situation when compared with the actual.(3)The GM(1,1)prediction model and LSTM prediction model are used to predict a monitoring point of the pit.The results of the two prediction models are compared and analyzed with the actual monitoring values,and the LSTM prediction model with better prediction effect and prediction performance is selected as the pit deformation prediction model,and the risk evaluation of the foundation pit is carried out through the prediction results,and the results are concluded to be consistent with The results are consistent with the actual results.