Research On Selective Preference Of Deep Foundations’ Excavation And Support Pattern In Reclamation Land Like Shenzhen

In the recent years, with the development of land reclamation, more and more deepfoundations appear in China. The biggest trouble is less experience about deepfoundation engineering in land reclamation. Neither does the calculation theory offoundation pit engineering and correct design method in those areas. Based on differentfilling material, method, foundation treatment and bracing structure, the deepfoundation engineering in Shenzhen reclamation land are facing huge risk, even qualitysafe accident.This paper starts from the technological Eco Park project in Shenzhen，the specificcharacteristics of deep foundation in the second district in topography, hydrological andgeological conditions, summarize the characteristics of deep foundation in reclamationarea. The article is based on document analysis, field investigation, numericalsimulation and practical engineering. Improved Analytic Hierarchy Process and thefuzzy comprehensive assessment method are also used at the same time. Some mainresearch work and innovations are shown below:①Summarize the characteristics of the pit.According to the experience listed inthe past, three excavation and support patterns are selected after qualitative analysis.②As the factors on selecting the best pattern are fuzzy, the fuzzy assessmentmethod is used for building the model of the project. There are so many disadvantagesin traditional Analytic Hierarchy Process that it is necessary to improve the AHP. A newmodel can exactly calculate each evaluation result of three excavation patterns whichincludes safety, quality, cost, schedule etc.③The ANSYS can finish modeling the deep foundation in the second district andmesh generation. Then put the solid model into FLAC3D, simulate deformation of the pit.The three different foundation displacement of the pit, internal force of supportingstructure and the deformation of monitoring points all provide a technical basis forselecting the best excavation and support pattern.④This pattern makes determining final excavation plan come true. The bestsupport plan is pile-anchor support plan.Some advices on foundation in the landreclamation area are listed in the end.