ACTIVE EARTH PRESSURE ON ABUTMENTS AND RETAINING WALLS IN RELATION TO SUBSOIL MOVEMENTS CAUSED BY EMBANKMENT FILLS

ERDDRUCK AUF WIDERLAGER UND STUETZMAUERN IN ABHAENGIGKEIT VON UNTERGRUNDBEWEGUNGEN DURCH DAMMSCHUETTUNGEN

WHEN A BRIDGE ABUTMENT IS BUILT INTO A FILLED EMBANKMENT IT IS USUALLY ASSUMED THAT THE RETAINING WALL DOES NOT PREVENT THE STRESS RELAXATION OF THE BACKFILL SOIL AND THUS ONLY HAS TO BE DESIGNED FOR ACTIVE EARTH PRESSURE. MEASUREMENTS OF MOVEMENTS AT ABUTMENTS HAVE SHOWN THAT THE OFTEN UNAVOIDABLE SETTLEMENT OF THE EMBANKMENT SOIL UNDER THE EMBANKMENT LOAD CAUSES A MOVEMENT OF THE ABUTMENT IN THE OPPOSITE DIRECTION. THIS CAN LEAD TO INCREASED EARTH PRESSURE ON THE WALL. THE OBJECT OF THE STUDY IS TO DETERMINE THIS INCREASED EARTH PRESSURE BY MEANS OF A LARGE SCALE MODEL. A RHINE SAND PUT DOWN IN LAYERS AND COMPACTED UNTIL MEDIUM-DENSE IS BEING USED AS FILL MATERIAL. THE MAGNITUDE AND DIRECTION OF THE EARTH PRESSURE AND THE MOVEMENTS OF THE WALL ARE BEING MEASURED. THE SETTLEMENTS OF THE SAND AND THE WALL ARE BEING VARIED, STARTING FROM THE NORMAL CASE WHERE THE WALL AND THE FILL SETTLE TOGETHER AND THE WALL ALSO ROTATES.