Analysis Of Soft Soil Creep Effect On Deep Foundation Pit Deformation

With the progress of the reform and opening up, Chinese economic constructionhas achieved rapid development. Along with high-rise, high-rise buildings in urbanconstruction increased, geotechnical deep foundation pit support has become a pop-ular. The supporting structure of the pit, excavation scheme and soil creep charac-teristics will impact on the foundation pit deformation control, thus affecting thesafety of the pit. This research analyzed the elastic resistance method which is com-monly used in foundation pit design process. The method based on the elastic theory.The m values are dependent on engineering and personal experience in the calcula-tion of earth pressure, and soil creep characteristics can not be considered. Thatmethod may lead to great error. Foundation pit supporting design in soils with therheological characteristics needs to use the finite element method for checking cal-culation.Common constitutive models and creep models in geotechnical engineering arestudied. The finite element software ABAQUS was used to simulate a deep pit pro-ject in Wuhan which used the traditional design method to design the foundation pitsupport plan. Drucker－Prager model was added in the simulated excavation pro-cesses to simulate mucky silty clay for considering the creep characteristic of softsoil, and the creep deformation law of the pit wall are obtained after analyzing thedeformation.By analyzing the deformation monitoring data in the excavation process, thecharacteristics of the of SMW Method pile deformation are obtained. The finite ele-ment method model deformation fitted with the actual monitoring results data verywell, and the accuracy of the model hypothesis has been verified further. Accordingto the foundation pit deformation creep characteristics, foundation pit support planis improved. Comparing the results of the new finite element model results with theoriginal one get the stress and deformation change of soil and structures. Calculation shows that creep deformation of soft clay accounted for more than53.6%of the totaldeformation. This result shows that reduce the pit soft soil creep the safety of the pithas a significant meaning. Comparison results proved that the soft soil creep willhave important impact on foundation pit deformation again. Therefore, the researchof soft soil creep characteristics and considering creep characteristics of the soil inthe foundation pit support plan design has important theoretical value and practicalsignificance.