THE MEASUREMENT OF EARTH PRESSURE ON RETAINING WALLS

A PARTICULAR METHOD OF MEASURING THE EARTH PRESSURE ON RETAINING WALLS IS DESCRIBED. THE SOIL PRESSURE CELL, KNOWN AS THE GOLDBECK CELL, IS USED. A BRIEF HISTORY IS PRESENTED OF THE DEVELOPMENT OF THE SOIL PRESSURE CELL. A BRASS DIAPHRAGM IS USED IN THIS CELL TO DETERMINE SOIL PRESSURE. THE ACCURACY OF THE DEVICE DEPENDS, IN LARGE MEASURE, UPON THE EXTREMELY SMALL MOTION OF THE WEIGHING DISK WHICH IS REQUIRED TO BREAK ELECTRICAL CONTACT DURING THE MEASUREMENT OF PRESSURE. SPECIFIC EARTH PRESSURE MEASUREMENTS ARE DESCRIBED. THE SOIL PRESSURE CELL SATISFACTORILY MEASURES EARTH PRESSURES, SOMETIMES AT DEPTHS OF 100 FT. OR MORE UNDER THE SURFACE OF THE EARTH. SOME OF THE DIFFICULTIES ENCOUNTERED ARE LISTED. THE SOIL PRESSURE CELLS HAVE ALSO BEEN EMPLOYED FOR DETERMINING THE PRESSURE DISTRIBUTION UNDER CONCRETE ROAD SLABS.