| Before starting any construction project,contractors need to ensure that they commence construction project on hard ground.If the construction of building is not doneon solid ground,then it may lead to repairs and instability later on.Therefore,modern techniques such as dynamic compaction,jet grouting,Deep mixing method(cement mixing pile),Vacuum preloading,Strong method,Replacement pad + geo grid combined with impact compaction are essential.For strong basement,ground improvement is necessary,because it reduces the risk of any damage later on.However,due to the close relationship between the ground treatment construction of the site and the foundation of the lower pile foundation,the displacement field caused by the ground improvement will have a certain impact on the bearing capacity of the ultra-long pile foundation.Therefore,the research work was carried out and the results will have a certain reference meaning for the future construction.The research will rely on the Wenzhou Olympic Sports Center as the engineering background to study the impact of vacuum preload on the adjacent ultra-long pile foundation.The content mainly includes three parts:(1)Determination of computational models and parametersThrough the collection of technical data at home and abroad and the investigation of technical trends,the latest progress of the research on the influence of vacuum preloaded pile load on ultra-long piles,including research methods and research results,that are mastered and also introduces the calculation principle of soil consolidation by vacuum preloading,then briefly describes the soil constitutive model of soft soil foundation,and finally determines the numerical calculation model and calculation parameters of ground improvement.(2)Analysis of the variation of soil displacement field caused by vacuum preloadingIn view of the complexity of geological conditions and the elastoplastic characteristics of soil,finite element software can be used to analyze the influence of surcharge on the displacement field of surrounding soils,especially in soft soil areas,focusing on the redistribution of soil displacement caused by soil consolidation.And analyze the variation law of the displacement field of the soil caused by the pile load.(3)Analysis of the influence of vacuum preload on the adjacent ultra-long pile foundationThe numerical simulation method and the two-stage analysis method based on soil deformation prediction are used to analyze the effects of vacuum preload on the stress and deformation behavior of adjacent super-long pile foundations;for different load modes(including load grade,different stack spacing and Different stacking rates and other factors)Analysis of the mechanical properties of adjacent pile foundation under different geological conditions(including the lateral deformation of the pile foundation and the variation of bending moment). |
