Abstract:

A reasonable and simple method is proposed to calculate the active earth pressure on rigid retaining wall under nonlimit state. Based on the unloading stress-strain relationship obtained from the unloading stress path experiment reflecting the stress-strain characters of soil in the active area behind the wall, the relationship between the friction angle and wall movement is established under nonlimit state. The sliding wedge, behind the retaining wall of not reaching the limit displacement, can be divided into numerous differential slices paralleling to the sliding plane. Then, with the force analysis of these differential slices and the relationship mentioned above, equations can be set up and the inclination of the sliding plane is also derived. Thereby, the calculation formula of the nonlimit active earth pressure is obtained. Subsequently, compared with one model test, the value of the calculated earth pressure has a satisfying agreement with the observed at the upper two-third of wall height and a certain deviation at the lower one-third of wall surface. The results show that the proposed method can provide a good prediction of active earth pressures for walls under nonlimit state and has some theoretical significance and engineering reference value.

Key words: active earth pressure, nonlimit state, friction angle, displacement