The Preliminary Seismic Design Method Of Gabin Reinforcement Soil Retaining Walls

Gabion material is a new structure combination of rigid and semi rigid and has come into our country for only one or two decades. Gabion material has a certain ability to withstand deformation, which showed good seismic performance.Because the development of Gabion retaining wall is limited in China, the studies of its dynamic characteristics and mechanism is very limited. The calculation and analysis of gabion reinforced retaining walls under seismic loading is a very complex problem, which is related to the interaction between the packing parameter, gabion material parameters, filler and reinforced. Firstly, the life of the gabion materials is inferred according to laboratory test; The finite element analysis for the mechanism and the dynamic properties of Gabion reinforced retaining wall is done using Geo-Studio Combined with shaking table test. Only to provide a reference for the application of gabion reinforced retaining wall in the country.The research contents of the thesis are as follows:The thickness of the gabion mesh is determined quickly by Gabion materials corrosion laboratory experiment in order to estimate its life. It is found that the anti-corrosion life of Gabion materials zinc coating is about30years. However, gap has a great influence on the corrosion resistance of the galvanized layer. The protective effect of the Galvanized layer will disappear ever since the gap emerges, the friction and trauma of Gabion is inevitable in the construction process. The gabion materials with foreskin should be used if condition allows in the project. Generally the foreskin materials are polymer materials with good ability of antacid and anti-alkali which is good for corrosion resistance of the gabion materials. For plastic foreskin is very sensitive to UV, it is very easy to be damaged in the region of strong ultraviolet rays. The ultraviolet rays is basically no effect on corrosion resistance of Gabion materials. What’s more, it is usually drought in plateau regions and corrosion reaction is anodic corrosion control which is beneficial to protect the integrity of the Gabion. As a result, it is recommend the use of plastic foreskin Gabion materials in strong ultraviolet radiation areas.According to the shaking table test results, curve of ground-breaking high pressure and acceleration along the wall is got. The earth pressure along the wall is high basically left concave distribution. That is to say, the earth pressure in the middle of retaining walls is relatively small because energy dissipation effect of the Flexible retaining wall in the process of earthquake. The above is the reason why a flexible retaining wall has superior seismic performance. Acceleration along the wall is high zoom, and the degree of amplification is related to the wall height, waveform and the peak size.For Flexible retaining wall has a certain deformation capacity, it is found that permanent deformation of the flexible retaining walls has no relationship with safety factor by Geo-Studio software simulation. For flexible retaining wall of2m, in the case of small earthquakes seismic permanent displacement and safety factor meet the specification requirements. However, in the case of large earthquake the maximum displacement is approaching specification allows for deformation and safety factor can’t meet the specification requirements. When the wall is4m, permanent displacement and safety factor meet the specification requirements for small earthquake. Safety factor meet the specification requirements for medium earthquake. And neither meets the specification requirements for big earthquake. When the wall is6m, everything can’t meet the specification requirements for big earthquake except permanent displacement for small earthquake. Thus it is not useful to judge the safety only using safety factor. Permanent displacement should be the other index. Permanent displacement is calculated by Newmark theory; safety factor is calculated by pseudo-static method.According to the simulation results, we get the following ideas for Seismic Design of Gabion reinforced retaining wall:the design of the Gabion reinforced retaining wall should regard the deformation as one of controlled conditions; Height restriction of gabion reinforced retaining wall is less than6m in railway and highway applications. Earthquake level should not exceed9degrees of earthquake intensity for retaining wall design (Peak acceleration is0.4g).