The Numerical Simulation And Research Of Performance Characteristics Of Geogrid-reinforced Soil Retaining Walls

Geogrid-reinforced soil retaining walls are widely used in various fields, such as highway, railway, architectural engineering, hydraulic engineering and so on. because of its remarkable economical benefits, constructing convenience, adaption to the foundation, simplicity of foundation treatment, good vibration resistance, shapely configuration and environmental pollution-free etc. However, the problems on strength, deformation and stability are not well settled in application of geogrid-reinforced soil retaining walls.Based on theory and practice of predecessors, the results of numerical analysis by a numerical nonlinear analysis model using a finite difference program FLAC^3D have been presented. The implications to design and construction based on the numerical results of current study are obtained and theory system for geogrid-reinforced soil retaining walls is developed.The main work in this paper is followed as:(1) Review the development and application on soil-retaining structure, soil-reinforced technique and reinforced soil retaining wall, and then summarize current theory research and trend of development on reinforced soil retaining wall.(2) Generalize engineering characteristics and applications on geogrid, and probe into modes and mechanisms of geogrid-soil interaction. Characteristics and influencing factors on geogrid-soil interface are studied.(3) Introduce the basic principle and features of a finite difference program FLAC^3D. Fast Lagrangian Analysis of Continua in 3 Dimensions. A applied numerical nonlinear analysis model considering the filling of layers by layers and loading step by step is developed for the geogrid-reinforced soil retaining walls , which is based on the Mohr-Coulomb elasto-plastic model of soils and zero thickness contact element model of interfaces. Compared the response calculated using FLAC^3D program to the observed behaviour, two cases for a full-scale test wall reinforced with geogrids and an actual geogrid-reinforced soil retaining wall of one-side facing constructed on a layered soil foundation are investigated to verify the rationality and availability of the proposed numerical model, which is a good test for the following numerical studies on features of wall performance.(4)Based on the above numerical approach, the overall behaviour of geogrid-reinforced soil retaining walls constructed on different foundations, including the stress and strain of the geogrids and deformation of the wall, can be investigated. Then effects of foundation strength and stiffness on the wall performace are researched.(5)Combining with the performance mechanism of reinforced soil walls, a comparative analysis for different wall heights is conducted for a varied range of strength parameters, including reinforcement stiffness, backfill strength and stiffness and geogrid-soil interface strength. Based on the computed results, the influence of these factors on the wall behaviour is discussed. In the end, some regular conclusions which are beneficial to the actual engineering are summed up.