Key Technique Research of Reinforced Soil Retaining Wall
|School||Nanjing Hydraulic Research Institute|
|Keywords||reinforced retaining wall reinforcement mechanism friction characteristics centrifuge model test deformation design method finite element method|
As a new kind of flexible retaining structure, geosynthetic reinforced retaining wall has been widely used in practice. However, the reinforcement mechanism has not been well understood. The current corresponding design methods and analysis theories are far inadequate for practical applications. The existing design methods are generally developed on base of the limit equilibrium state theory to perform the analyses of stabilization. The influence of deformation on reinforced retaining structure has not been well considered. This will absolutely draw back advanced development and application of the reinforced retaining structures.In this thesis, literature review on the existing research of reinforced retaining structure is performed. Then, further study is conducted on the reinforcement mechanism, design method and analysis theory. This thesis includes the following parts:(1) Direct shear test, tensile test and triaxial test are performed to study the reinforcement mechanism and soil-geosynthetic interface behavior. Different fills and reinforced materials are used in the tests. The characteristics of the stress-strain curves are analyzed. Good combination of fills and reinforce materials is suggested for applications.(2) Centrifuge model test is performed as well. The influence of length and spacing of geosynthetics, and the rigidity of the reinforced materials are studied by comparing the deformation behavior of the reinforced retaining structures.(3) Finite element analysis is conducted to assess the influencing factors for the reinforced retaining structure. Good design parameters are suggested. It is also suggested that the soil parameters have an important influence on the behavior of the structures. A deformation controlled design method is suggested.(4) Base on the concept of "equivalent additional stress method", a new finite element is suggested. Geosynthetie material and soils are jointly incorporated in mesh formation. The geosynthetic element has free deformation on each node, which is formulated by means of the deformation of surrounding soil elements so that compatibility of deformation is assured and force is transferred through soils to geosynthetics. The end of the geosynthetics is attached on the retaining structure, thus a composite reinforced retaining structure can be analyzed by finite element.(5) Finally, summary and conclusions are drawn. Further research and some drawbacks are assessed.