Research On The Impact Of Pre-tension In Reinforcement To Static Performance Of Reinforced Body

Unbonded prestressed reinforced earth technique has great advantages over the conventional reinforced earth structure by applying a pre-tension of reinforcement to actively constraint filler material. The pre-tension in reinforcement is the basis of the unbonded prestressed reinforced soil technology, the values of which directly affects the mechanical properties of reinforcement. The effect of pretension in unbonded prestressed reinforced material on the mechanical properties of reinforced body is of great values to reveal the working mechanism of unbonded prestressed reinforced body. Present paper conduct several model tests to study its static mechanical properties, which consist of a common reinforcement test and a single unbonded prestressed reinforcement test as well as a double unbonded prestressed reinforcement test. Finally, comparative analysis is conducted and the results are as the follows:(1) Considering the tension and anchorage characteristics of reinforcement in unbonded prestressed reinforced earth technology, the author design and product a tension bracket, which shows that the system has good operability in practice, and obtained the corresponding invention patents and utility new patent.(2) Theoretical demonstration and design calculation of the scale model test were completed. Though contacting similarity ratio of centrifugal model test the rationality of the scaled model was discussed. The fillers, reinforcements and panel in model test were also designed. Level of prestress, length of reinforcement and the design calculation of anchor plate were determined by reference to the theory of anchor plate retaining earth structure. Besides, the panel system and test program of the model test were designed and produced.(3) A comparative analysis of the experimental results was carried out among single unbonded prestressed reinforced body, common reinforced body and double unbonded prestressed reinforcement. With the pre-tension increasing, the back pressure of panel adjacent to prestressed reinforcement increases. However, the horizontal deformation of panel and the strain of fiberglass geogrid adjacent to prestressed reinforcement decreases. Besides, settlement on the top of reinforced body is closely related to the location of the top panel and reinforcement. The distribution of prestress in reinforced body is symmetric in the horizontal plane and different in the vertical plane. The rigidity of the reinforcement was increased due to the reinforcement which provide lateral restraint at the panel side. The pre-tension in reinforcement was increased with the increase of filling. There is less interaction between reinforcement of different height with the increase of pre-tension among layers. A slight loss of pre-tension was appeared after the completion of the pre-tension. Lateral heaping load has little effect on the change of pre-tension and the horizontal deformation as well as the back pressure of panel.