Relationship between cell-indicated earth pressures and field earth pressures in backfills

Pressure indicated by earth pressure cell (EPC) often deviates from field earth pressure . EPC in normally consolidated soil was analysed with Taylor’s indentation method. It is found that assumes a linear relationship with soil’s compression modulus and . When preconsolidation pressure imposed on overconsolidated soil is unloaded, soil’s rebound strain is greater than EPC’s, and a gap between EPC’s sensing plate and soil appears. Upon reloading, contact between sensing plate and soil resembles spherical contact. This contact was analysed with Hertz’s solution and it is found that is in direct ratio with , and is less than for a relatively low earth pressure and is greater than for a relatively high earth pressure. Earth pressure measurement experiments were conducted with river sand. Experimental results conform to the theoretical analysis herein for a relatively low earth pressure made in this paper.