Study On Seismic Behavior Of Wrapping Geogrid Reinforced Soil Structures

China is located between the Circum-Pacific seismic belt and the Eurasian seismic zone and has a significantly vast territory that is seismically active.Because of its geological placement,China is more frequently prone to earthquakes.For this reason,geotechnical infrastructure such as the foundations of highways,railways,bridges,buildings and other structures such as the slopes and dams are vulnerable to damages in the earthquake disaster zone.These infrastructures undergo damages or are totally destructed during an earthquake and contribute to significant economic losses.With the proposal of the ‘Belt and Road' initiative in China,the construction of transport infrastructure has also been given priority to link the unconnected road sections,which pass through many earthquake-prone areas.Therefore,in the face of China's increasing seismic demand,good seismic performance has become the main design points of road traffic structures in China.With good seismic performance and economy,reinforced earth structure has been widely used in the construction of transportation infrastructure in recent years,such as reinforced-soil embankment,reinforced-soil retaining wall,reinforced-soil slope and so on.Scholars at home and abroad have done a lot of research on the design and engineering application of reinforced-soil structures.However,there are few studies on the new type of flexible geogrid reinforced-soil structure,and many problems need to be solved urgently.For example,the understanding of the seismic response law of geogrid reinforced earth structure is not thorough;the key factors affecting its seismic performance are not clear and the failure mechanism of geogrid reinforced-soil structure under seismic action is not well understood.In view of this,in this paper,the seismic performance of geogrid reinforced-soil structure under seismic action is studied by means of shaking table test and numerical simulation.The main work includes:(1)The shaking table test of seismic response is carried out for a new type reinforced soil slope with flexible wrapping geogrids.The dynamic response,deformation characteristic and failure phenomena of reinforced soil slope under different amplitudes of earthquake are obtained.Based on the acceleration,earth pressure,strain value of geogrid,horizontal displacement and vertical settlement obtained from the test,the seismic response law of reinforced body is analyzed.(2)The finite element program is used to carry out numerical modeling and analysis of the shaking table test,and the accuracy of the numerical modeling method is verified by the shaking table test data.Finally,based on the model,the failure mechanism of the new type geogrid reinforced soil slope subjected to earthquake is further analyzed.(3)Using the validated numerical modeling method and combining with the reinforced earth embankment used in engineering practice,the numerical modeling analysis is carried out.Based on this model,the rationality of commonly used reinforcement forms in engineering is verified.The influence of reinforcement distribution with different length of reinforcement on dynamic stability of reinforced earth embankment is further studied.Based on the test and numerical simulation results mentioned above,it is found that the new wrapping geogrid reinforced soil slope has good seismic performance and can be widely used in engineering.Moreover,it is also found that reasonable reinforcement arrangement can better improve the seismic performance of reinforced soil structures.