Study On Calculation Method Of Dynamic Earth Pressure Of Retaining Structure Considering Displacement Mode

In the construction process of roads,bridges,etc.,there are many applications of retaining structures.The overturning and slipping of retaining structures are the main forms of failure of retaining structures.The anti-seismic design of the retaining structure in foreign countries is based on the seismic design concept of displacement and performance.However,the seismic design of earthquake-resistant design in China is based on the seismic concept of the retaining structure.The seismic design of the retaining structure based on displacement and performance can calculate the damage level of the retaining structure.Destruction identification and maintenance use,and the force-based anti-seismic method of retaining structure can only judge the damage or non-destruction of the retaining structure,which is not conducive to the evaluation of the damage degree of the retaining structure.In view of this,this paper uses the Newmark sliding theory to study the distribution of dynamic earth pressure under the retaining soil after the retaining structure is layered soil,different displacement modes and under the water level,and analyzes the rotation and sliding displacement of the retaining structure.The main findings are as follows:?1?Considering the influence of flat curvature surface,seismic coefficient and wall back friction angle and soil interlayer angle on earth pressure,the calculation method of earth pressure under different displacement modes under the earthquake action of retaining structure is proposed.By comparing with experimental data,The rationality of this method is verified.At that time,the earth pressure distribution in the RB mode,the earth pressure intensity distribution of the flat rupture surface and the earth pressure intensity distribution of the curved rupture surface are not much different,and the shape of the rupture surface is less different;In the RT mode,the earth pressure intensity distribution of the flat rupture surface is always larger and smaller than the earth pressure intensity distribution of the curved rupture surface.The intensity distribution of the passive earth pressure is exactly opposite to the above rule,and the distribution shape difference of the rupture surface is also More obvious.At that time,the earth pressure intensity was obviously nonlinear,the earth pressure distribution in the RB mode,the earth pressure of the curved fracture surface was greater than the earth pressure of the flat fracture surface,and the shape difference of the fracture surface was relatively large;The distribution of earth pressure intensity is opposite to the above rule,but the shape of the fracture surface is also quite different.?2?Considering the influence of groundwater level and the ratio of super-pore pressure on the distribution of earth pressure under earthquake action,the calculation method of saturated earth pressure under earthquake action is proposed,and the retaining force under the influence of super-porosity ratio and flat-curved rupture surface is revealed.The distribution law of structural earth pressure intensity.For the calculation of the dynamic earth pressure of the partial backfill under water,the difference between the proposed method in the US Coastal Retaining Structure Design^[17]and the method proposed in this paper is mainly due to the use of the equivalent gravity of the soil to the retaining structure.The seismic coefficient is amplified by amplification.For the active earth pressure,the earth pressure of the retaining structure is larger than the value of the flat rupture surface;for the passive earth pressure,this is the opposite;in the two displacement modes,whether it is the active earth pressure nor the passive earth pressure is also reduced as the excess pore pressure ratio increasing.?3?Using the calculation method of the dynamic earth pressure under the earthquake action proposed in the paper,combined with the Newmark calculation theory,the displacement calculation method of the retaining structure under earthquake is proposed.The retaining structure is immersed in water,and the excess pore water pressure has a great influence on the displacement of the retaining structure.The smaller the dynamic earth pressure,the more the sliding displacement decrease;The friction coefficient between the retaining structure and the site has a great influence on the sliding displacement of the retaining structure.Therefore,in the construction process of the retaining structure,the well-filled fill or the site should be selected as much as possible to reduce the retaining structure and the site;The influence of the coupling and non-coupling between rotation and sliding on the displacement in different displacement modes is analyzed.After the retaining structure slides,its sliding state will slightly suppress the rotational displacement of the retaining structure,and the sliding displacement of the retaining structure will be largely suppressed after the retaining structure rotates.