Deformation-property Study Of Deep Excavation Supported By Steel Pipe Sheet Pile In Sea Reclamation Areas

At present, with the accelerating urbanization process of coastal areas in our country, urban construction land in coastal areas is increasingly strained; On the other hand, China, as the world's major exports of industrial products and energy importing countries, must urgently increase the port throughput. Considering the two aspects, it is required to carry out sea reclamation in large scale to meet the need of urban construction land of coastal areas and port construction. Along with the abundant appearance of large-scale sea reclamation in order to meet the requirement of transportion, municipal facilities, business, industry, etc, large-scale excavation engineering should be carried out in sea reclamation areas. However, the study of deformation properties of deep excavation supporting structure in sea reclamation areas and theoretical study of unloading path for reclamation soil have not been systematicly investigated. One deep excavation engineering of Cao Feidian sea reclamation area in Tangshan City, Hebei Province is the research objective in the dissertation. Research results as follows:(1) Considering the soil layer properties in sea rclamation areas, monitoring scheme of deep excavation engineering is established. According to the code requirements and combining the engineering facts in sea reclamation areas, some issues such as control index of each monitoring item and monitoring frequency are made relative feasibility analysis.(2) Based on measured datas, characters of surface settlement, displacement of pile top, pile displacement, internal force of supporting system and change of subsoil water level of deep excavation which is supported by steel pipe sheet piles is studied in sea reclamation area. The trend of each safety control index in the process of deep excavation in sea reclamation areas is presented across-the-board, and properties of deep excavation in sea reclamation areas are recognized by these rules.(3) Influence of pit deformation which caused by adjacent excavation is analysed by measured data in the field, and factors of two facets include excavation depth and adjacent distance are researched. Deformation properties are analysed comparatively when the deep excavation is supported or unsupported.(4) Influence factors of supporting structures deformation and influence degree of each factors to the support deformation are analysed for deep excavation engineerings in sea reclamation areas by calculation software, and reasonable suggestion about excavation design in sea reclamation area are presented.