The Study Of The Seismic Active Earth Pressure Of Different Retaining Wall Displacement Mode With Pseudo-Dynamic Approach

The calculation of seismic earth pressure is a complicated systemic problem because of many factors involved. Since the proposal of the M-O theory, many scholars have adopted various methods to try solving the problem and also have achieved fruitful results. But there are still a lot of issues that could not be explained appropriately so that it is of course worthy of keeping on working on the territory. Based on the assumption of the M-O sliding surface, the article uses the Pseudo-dynamic way in which the seismic pressure is attached to discuss the seismic active earth pressure of different displacement modes combined with the oblique slices method. The following results are obtained:(1) The article puts forward a general formula for calculating the seismic active earth pressure, in which the amplification effect of the earthquake acceleration is taken into consideration. Besides, the author has also corrected the formula aiming at handing the existence of the tension crack in the cohesive soil. By using the method, the seismic active earth pressure distribution> the resultant force and its position can be got at any time within predominant period. The calculating formula is suitable for the following complex circumstances such as the filling soil of cohesive or cohesionless soih different wall back patterns(up-dip、verticality and down-dip)、the inclined filling soil surface and the applied uniform overload. In this paper, it is also discussed that the influence of various factors on the critical sliding surface、 the seismic resultant force、its applied position and earth pressure distribution.(2)The determination of the seismic active earth pressure by method combined Pseudo-dynamic approach and Coulomb soil theory as well as the solution incorporating the Pseudo-static approach and oblique slices method is proposed. And with the comparisons of the three methods, the differences between the various results are easy to find out.(3) The numerical relationships between the soil property parameters and the soil displacements in diverse wall displacement mode got by the former researchers are summarized. Utilizing the recommended seismic active earth pressure formula, the paper presents the gradual changes of the seismic active earth pressure and its distribution with the displacement in distinct wall displacement pattern.(4) The specific engineering example shows that the appropriate displacements of the wall can bring the soil strength into full play, thus the seismic active earth pressure on the wall can be decreased which improves the seismic stability of retaining wall.