Soil Sample Analysis And Deformation Prediction Of Deep Foundation Pit Engineering

With the development and utilization of underground space in China,underground structures are being larger and deeper.Hence,there will be more and more cases that foundation pit supporting structure affected by complex surroundings,and the excavation of foundation pit,certainly,will affect its surroundings,like buildings,structures,underground pipelines and so on.Reducing the influence of the excavation needs supporting system with a certain degree of reliable.It is difficult to ensure the safety of surroundings during the excavation that support structure designed merely based on theoretical knowledge,technical specifications and engineering experience.Accident frequently occurred because of improper design,it is very important to strengthen the research on the characteristics of the soil around the supporting pile,to predict and simulate the deformation of the support body and its surroundings,which can provide experience and guidance for the future engineering practice.Predicting and controlling the stress-strain of supporting structures to make sure they can support it is surroundings,which is the key to a successful foundation design.In this paper,a deep foundation pit project in Wuchang district of Wuhan is the background.This paper analyzed the stress-strain of the supporting structures and it is surrounding soil by numerical simulation and least-squares method.The real time stress-strain data of the supporting structures,used in numerical simulation and least-squares method,was collected regularly during every construction stage,aim at the complicated environment.This paper attempts to study the characteristics of deep foundation pit soil by triaxial compression test,Geostudio is used to simulate the excavation process of deep foundation pit,then the time series prediction of the horizontal displacement of the supporting structure is carried out based on the improved least square model.The results show that the soil shear strength can be obtained by triaxial compressive shear test,this can provide basis data for simulation.The simulation is used to discuss the rule of the stress and strain change of the supporting body caused by the change of earth pressure during excavation.Using the improved least squares model to predict the horizontal displacement of the support structure and the results are similar to the actual monitoring data.