Seismic Stability Analysis Of Flexible Reinforced Soil Bank Retaining Wall

Since the "Belt and Road" strategic cooperation,China has accelerated the construction of a large number of port structures in coastal areas.However,most of the ports along the “Belt and Road” are located in the seismically active areas of the AsiaEurope Plate,Indian Ocean Plate and Pacific Plate.Both domestic and foreign port engineering earthquake damage cases have caused serious economic losses and casualties.Therefore,the performance of near-shore port engineering structures under the action of earthquakes has become a hot issue studied by scholars from various countries.At present,most of the revetment structures in port engineering are gravity retaining walls.Under the action of earthquakes,the port revetment retaining walls have poor seismic performance and adaptability,are prone to irreparable rigid damage,and have high requirements for foundation bearing capacity,which is not suitable for Soft ground is prone to uneven settlement.The flexible reinforced soil bank retaining wall is an ecological flexible structure that uses geogrids to reinforce the soil to improve the stability of the retaining wall.It is not easy to damage under the action of earthquakes,and it has low requirements on the bearing capacity of the foundation.Backfill material can be taken on site,and its economic,ecological and social benefits are very significant.Therefore,the flexible reinforced soil bank retaining wall can meet the needs of earthquake prevention and disaster mitigation of port engineering.At present,there are few studies on the reinforcement-soil interaction of the flexible reinforced soil bank retaining wall,the coupled response of the earthquake and groundwater,and the failure mode under the action of earthquakes,which limits the application of this economically reasonable flexible structure in port engineering.Therefore,studying the seismic stability of the flexible reinforced soil bank retaining wall,analyzing its hydrodynamic coupling response,and discussing the distribution law of its potential rupture surface under earthquake action have important engineering value for popularizing the application of flexible reinforced soil bank retaining wall in port engineering,and provide new ideas for the seismic design theory of flexible reinforced soil bank retaining wall.Based on the existing research,this paper takes the flexible reinforced soil bank retaining wall as the research object,with the help of the dry-wet cycle pull-out test,shaking table test and hydrodynamic coupling numerical simulation,focusing on the studying the reinforcement-soil interaction of reinforced soil under dry-wet cycle,the hydrodynamic coupling response law of flexible reinforced soil bank retaining wall,the distribution law of potential fracture surface,etc.The main work contents are as follows:(1)For the flexible reinforced soil bank retaining wall,dry-wet cycle test and pullout test of reinforced soil were carried out,mainly to study the influence of dry-wet cycle number,overburden pressure,moisture content and other factors on the interface parameters of reinforced soil.(2)For the flexible reinforced soil bank retaining wall,the shaking table test results are used to verify the correctness of the numerical analysis,and the coupling analysis of the seepage field and the stress field is carried out by numerical analysis methods.The hydrodynamic coupling response law of displacement,earth pressure,shear strain increment,pore water pressure and geogrid tensile stress are studied.The effects of seismic acceleration peak,revetment height,slope and water level height on the seismic stability of reinforced soil revetment retaining wall are also studied.(3)Based on the numerical analysis results of the hydrodynamic coupling of the flexible reinforced soil bank retaining wall,the distribution rules of potential fracture surfaces were extracted and summarized,and a multi-line simplified fracture surface suitable for flexible reinforced soil bank retaining wall was fitted.Based on the above dry-wet cycle test,pull-out test,shaking table test and numerical simulation results,it is concluded that the flexible reinforced earth revetment retaining wall can improve the seismic stability of port revetment and meet the needs of port engineering for earthquake prevention and disaster mitigation.Moreover,the simplified fracture surface of polyline provides a new idea for the seismic design theory of reinforced soil structure.