Numerical Modelling Of Deep Excavation And Research On Field Observations

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.Under the complicated geologic condition with weak watery strata in Tianjin, difficulties and risks of deep and large foundation pit construction are very intractable in congested urban areas in close proximity to the existing structures and facilities. As a result, safety of construction and environmental protection become an urgent problem. The research on some problems such as the stability of the foundation pit during excavation, dewatering and deep soils displacement is the key to ensure the safety of construction and environment. Tianjin Causeway Bay Plaza foundation pit engineering is the typical case of deep/large excavation and its scale and depth is rare in district of Tianjin. Combined with Tianjin Causeway Bay 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, large-scale 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, the seepage field, deformations, stress distribution and the bracing response had been calculated during underground excavation by steps of the practical engineering. The contents include:In-site experimental study was conducted for deep excavation in Tianjin Causeway Bay Plaza. 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 ring beam and the influence on environment in the course of excavation. Through these analyses, the law of horizontal displacement in adjacent soil was obtained.