INFLUENCE OF SEEPAGE FLOW ON EARTH PRESSURE AGAINST RETAINING WALL

Abstract

In order to investigate the influence of seepage flow on active earth pressure, the authors performed earth pressure tests under the condition that rainfalls seeped into the backfill and ran slowly through it and then drained into a filter located between the wall and the backfill. It was found that the resultant force of the active earth pressure acting on the wall increased due to the influence of the seepage flow and the influence became more pronounced as the slope of the backfill surface increased.The values of the active earth pressure calculated by the logarithmic spiral method taking into account the seepage flow in the backfill, agreed with the observed values. It has been proved that the calculation method developed by the authors is reasonable.The authors compared the coefficients of horizontal component of the active earth pressure proposed by Terzaghi and Peck for clean sand or gravel with the values calculated by the authors. It was estimated that Terzaghi and Peck had taken into account two thirds of the increase of the earth pressure due to seepage flow.