Study On Influence Of Soft Clay Interlayer On Quality Of Cast-in-place Pile And Safety Of Foundation Pit

With the continuous rapid development of our country’s economy,the scale of our country’s cities is constantly increasing,reinforced concrete bored pile is also constantly used in the construction and development of our country.With the construction of cast-in-place pile,there will be a series of pile quality problems.It is of great significance to ensure the integrity of pile quality for the safety and stability of pile foundation engineeringBased on the foundation pit support project of Smart City Operation Service Center(IOC)of Beijing future science and Technology City,combined with relevant survey data,regional geological traceability data and field experiments,this paper studies the influence of soft clay layer in the site stratum on the quality of cast-in-place piles and the safety and stability of foundation pit retaining structure.The main contents of this paper are as follows(1)Combined with the previous geological exploration and regional geological data,the physical and mechanical properties of the interlayer soft clay are tested,and the approximate thickness,basic physical and mechanical properties,compressibility and shear strength of the interlayer soft clay are obtained;(2)According to the statistics of the degree and range of hole collapse and diameter expansion of bored pile,the reasons of hole collapse and diameter expansion of bored pile are analyzed by combining with the physical and mechanical indexes of soil layer.The influence of stratum reasons on the quality of bored pile is analyzed by using the method of numerical simulation test.Finally,the causes of hole wall instability are summarized and reasonable solutions are put forward based on the field and experimental data,It provides theoretical experience for the construction of bored pile in the future;(3)According to the stress and deformation characteristics of foundation pit supporting structure,the rationality of foundation pit supporting structure design is analyzed,and the influence of collapse hole expanding supporting pile on the safety and stability of the whole foundation pit supporting structure is analyzed;(4)The whole foundation pit supporting engineering is simulated in the construction stage of foundation pit excavation.The deformation of foundation pit supporting structure is simulated under the condition of theoretical foundation pit supporting design.Compared with the field foundation pit monitoring data,the influence of expanded bored pile on the deformation of foundation pit supporting is analyzed,and the soft clay of foundation pit is optimized by numerical simulation,The influence of soft clay layer on the deformation of retaining pile and foundation pit soil is analyzed;...