Deep Foundation Field Test Analysis And Numerical Simulation,

In recent decades, a great deal of underground engineering is under construction or reviews in many cities, and at same time many problems in deep excavation projects will also come forth. So the geo-environmental problems become more and more important in design and construction of substructures with the scale and depth of excavation increasing.Combined with Shenzhen Guilong homestead excavation engineering, relative studies in this dissertation are carried out. On the basis of reading a lot of literatures and summarizing the former research achievements,in-site monitoring has been done in view of response of support system and displacement of adjacent soil during the process of deep excavation.Finally,using finite element program, deformations,stress distribution and the bracing response had been calculated during underground excavation by steps of the practical engineering. The contents include:(1) In-site experimental study was conducted for deep excavation in Shenzhen Guilong homestead. It includes support system response and horizontal ground movement. This study uses field data from case studies to discuss in detail the characteristic of internal force change and deformation in cable and the influence on environment in the course of excavation. Through these analyses, the law of horizontal displacement in adjacent soil was obtained.(2) The FLAC numerical analysis is performed for the support system in Shenzhen Guilong homestead excavation engineering. In the analysis, soils,retaining structure and horizontal cable structure are modelled integrally with excavation sequence and the interactive response between soil and structure is investigated. By comparing between field data with the computing result,the results obtained show the important role of FLAC can play for the prediction and evaluation of the field response and support associated with underground excavations involving many complex factors. The applicability of the support system type on deep excavation is verified furthermore.(3) This thesis has analyzed the response of soils and the behavior of support in the process of excavation by steps. The results acquired by means of numerical simulation in this thesis is reasonable and that the prediction before construction is proper is also proved. So theoretical basis and guidance are provided to actual engineering and these can contribute to improve the structure design level and safety. Valuable design, construction and scientific research experiences are cumulated and provided to the similar engineering.(4) Finally, the principle of design-optimization of deep excavation engineering is expounded in the thesis. The main methods and ways of design-optimization are proposed.