Study On The Mechanical Behavior And Design Method Of Geocell Flexible Retaining Wall

Geocell flexible retaining wall is a new flexible retaining structure. It can meet the requirements of ecological restoration, greening the surface of wall and beautifying the landscape along the highway, and it will have broad application prospect. However, its mechanical behavior coupled with the common role of the wall and the filling soil, so the stress and deformation is complex. In addition, the related design and construction processes were imperfect. These factors severely hamper the engineering applications of the new retaining structure. Therefore, the research on the calculation of earth pressure and displacement has great practical significance for the designing and promoting the use of geocell flexible retaining wall. Moreover, the study on the earth pressure of flexible retaining wall also has important academic value.This paper focus on the mechanical properties of geocell flexible retaining wall, begining with the action mechanism and deformation characteristics of geocell flexible retaining wall, and combining with centrifuge mode test and finite element simulation analysis, a systematic study for mechanical characteristics and design methods of geocell flexible retaining wall has been carried out. Some new progress are made in following5aspects.LA systematic study for the defomation characteristics and earth pressure of geocell flexible retaining wall is done by using the numerical simulation method, and the law for defomation characteristics and earth pressure of geocell flexible retaining wall is obtained. The earth pressure of the wall is a clear non-linear distribution, and the earth pressure gradually increases from the top to the bottom of the wall, but, there is a turning point in the middle of the wall where the earth pressure of the following part increases dramatically. There is a dividing point in the middle of the wall, above the dividing point, the horizontal displacement is near to translation, and the other part can be approximated as rotation around the foot of the wall. Similarly, the vertical displacement of the wall shows obviously non-linear. Besides, the effect laws of the earth pressure and displacement from the change of the design parameters has been studied.2. Using centrifuge model test, through six different forms of structural model test, the horizontal deformation and earth pressure distribution of the geocell flexible retaining wall are studied. By comparing and analysing the laws of earth pressure and horizontal displacement from different structural forms of geocell flexible retaining wall, the changed range of the bulging deformation point has been found, and the numerical results for the geocell flexible retaining wall are verified. Meanwhile, the research results also provide the foundation for earth pressure calculation and design methods of geocell flexible retaining wall.3. The earth pressure theoretical calculation of geocell flexible retaining wall has been studied. Based on the horizontal deformation features of geocell flexible retaining wall, the horizontal displacement of the wall is simplified the translation model and the rotating model round the bottom of the wall. The author puts forward a corresponding calculation of earth pressure, and gives the calculating formula for earth stress by theoretical derivation.4. The displacement calculation method of the geocell flexible retaining wall has been study.Firstly, the retaining wall is simplified as cantilever, and the forces and boundary conditions of retaining wall is transfered to the cantilever. Then, in accordance with the force and boundary conditions of the cantilever, the theoretical derivation of the calculation formula for the deflection and Axial compression of the cantilever is presented. Finally, in accordance with the corresponding relationship between the cantilever and the retaining wall, the wall displacement formula is given.In the case of given parameters, the wall displacement is calculated and compared with the numerical calculation results.5. Based on the calculation methods of earth pressure and displacement, the design method of the geocell flexible retaining wall is proposed. Combined with the engineering practice, the author gives the structure forms and the simplified calculation model of the flexible wall, and discuses the simplified calculation method of load at the top of the wall. Considering the interaction between materials, wall stability, security reserves, and other factors, the wall deformation control standard that the maximum deformation does not exceed5%height of the wall is proposed. Based on the deformation control standard as well as the calculation methods of earth pressure and displacement in this paper, the calculation and checking methods for related parameters of the wall is given, and the initial proposed design method of flexible retaining wall is put forward. On the basis of the calculation, considering the construction factors and the adverse conditions of precipitation, the design suggestions value of wall thickness was given.These achievements have great significance for the design, construction and applications of the wall and the earth pressure calculation method for the flexible retaining wall also has important academic value.