Test Analysis And Numerical Simulation Of Reinforced Red Sandstone Earth Retaining Wall By Geogrid

Red sandstone contains more clay minerals with the nature of hydrophilic. Under the influence of atmosphere, temperature and humidity, it is easy to soften, disintegrate and its engineering nature deteriorates. When the red sandstone is used as roadbed filling, project defect such as uneven settlement, slope dilapidation is easy to occur. However, with the fast development of highway construction, red sandstone has been more and more being used for road fill. Therefore it is urgent that the technology of red sandstone used as fill in road construction should be studied in order to safeguard the long-term stability of red sandstone embankment.Reinforced Earth technology can effectively improve the tensile strength of soil, changing the soil's internal stress-strain field, improve the stability of soil. Thus, it has been widely used in the fields of civil engineering, such as water conservancy, highway, railway, construction etc.Based on a reinforced earth retaining wall of a highway in Hunan, the mechanism of geogrid reinforced coarse-grained red sandstone was studied by large triaxial tests, the interaction between geogrid and coarse-grained red sandstone was studied by pullout tests, and the structure properties and its influence factors of geogrid reinforced earth retaining wall filled with coarse-grained red sandstone have been numerically studied by FLAC3D in this paper. The following conclusions have been gotten:1. The basic theory and design method of reinforced earth retaining wall are analyzed systemically.2. Through large triaxial tests which tested on non-reinforced, reinforced with two layers and three layers geogrid samples, the mechanism of geogrid reinforced coarse-grained red sandstone has be studied.3. The interaction of geogrid and coarse-grained red sandstone has been studied by pullout test which the device was made by self, and the parameters of interface have been gotten. This work provided basic data for design and numerical analysis.4. The structure properties of geogrid reinforced earth retaining wall filled with coarse-grained red sandstone have been numerically studied by FLAC3D. The deformation rules, the stress characteristics of reinforcement and the distribution rule of earth pressure have been gotten and the influence of fill, reinforced space and the length of reinforcement to the lateral deformation of the reinforced earth retaining wall have been studied.