Study On The Design Of Soil-Nailing In Loess Zone

With the rapid development of Chinese economy, the infrastructure has become a major pillar of the economy, and the excavation and backfilling problem of the slope will be encountered in urban construction, construction of roads and railways. In order to prevent the occurrence of slope slides and mud-rock flow, it is inevitable to support it. In recent years, Soil nailing technology has been becoming more and more in deep excavation and slope engineering in urban construction. Soil nailing technology overcomes the technical defects of the traditional support technology, and it will have broad prospects. However, due to not enough depth Analysis on soil nailing technical, generally a single and old supporting structure is selected, thus usually more waste and the insecurity in use in the project would appear. Therefore, we need to have a study on the design of permanent flexible support structure, and it must be considered that earthquake and it durability and so on.Based on the supporting structure design theory in loess region, the design of soil nailing will be studied, and will build 3-D finite element model to analysis the structure of soil ailing more comprehensively, and it is revealed further that the deformation characteristics of soil nailing in the entire process of excavation and the influence of the performance parameters of soil nailing to the internal forces and the deformation. In this paper, the follow is studied:(1) It is discussed that the formation, research, the technical characteristics, type, scope and development of the soil nailing technology;(2) The inadequate of the existing lateral soil pressure is analyzed, and a new of the side earth pressure distribution model is introduced;(3) Base on the existing literature, the formula of the checking of Stud-surface is given;(4) For permanent soil nailing engineering, a number of measures of deformation control and durability design is given;(5) with soil nailing structural practice engineering of a deep excavation, by large-scale finite element analysis software ADINA, build a overall three-dimensional finite element model in numerical simulation, and in the model it is considered that the friction between soil nails and soil and the linear process of change of the life-death unit between the unit Stiffness and rigidity and zero to make it meet to the actual project, and it is analyzed that the displacement of the pit in construction process , the change process of soil nailing force , and its maximum level displacement and facing- soil head is checked .