Composite Soil Nailing Wall Numerical Analysis And The Bearing Mechanism

Composite soil-nailed wall, which has been used during the recent years, is a new supporting form of the foundation pit. It is successfully applied in the loose-soft soil and the area full of underground water. There are many useful results that the research for the bearing and deformation mechanic of the composite soil-nailed wall during the construction. It has no research results that we use composite soil-nailed wall in the area which is located in north-west loess soil area where is full of underwater and concentrated buildings. Based on the formers' results, this paper has established non-linear FEM calculation mode. According to the results of non-linear FEM and the data of field in Xi'an, this paper summarized the bearing and deformation mechanic of the composite soil-nailed wall. The main researches are as follows:Summing up domestic and foreign the development history and the current situation of the research on soil-nailed; Summing up the background and present condition of the research on composite soil-nailed wall.Review the composition and the construction of the composite soil-nailed wall, and analyze its engineering characteristics of the main of form construction, its method and techniques characteristic.Aimed at the characteristic of the constructing composite soil-nailed wall, the paper has established non-linear FEM calculation mode, including simulation of soil, mixing pile-soil, soil-nailed, Goodman interface element.According to the data of the field measurements, this paper has used non-linear FEM separately in different geology conditions, analyzed deformation characteristics, internal force and extension areas destroyed regulation of the composite soil-nailed wall during the progress of the construction and summarized the bearing and deformation mechanic of the composite soil-nailed wall. Geology conditions have decided the bearing and deformation mechanic of the composite soil-nailed wall. In the loose-soft soil and the area full of underground water, the maximum horizontal displacement is located in middle of the wall, and the maximum vertical displacement is located in the middle of the upside load. In the more strength soil, the maximum horizontal displacement is located in the top of the wall, and the maximum vertical displacement is located in the edge of deep excavation pits, so it looked as "decline slope".Based on the data of the field measurements and the calculation's results, this paper has summarized the bearing and deformation mechanic of the composite soil-nailed wall in different geology conditions, and this useful research results have provided the theoretic foundation for this technology. According to the calculation's results and the working skills of the field, this paper has given some beneficial advices on the composite soil-nailed wall's design and work.