Most existing passive earth pressure theories are not completely suitable for the calculation of unsaturated backfill in practical engineering, especially for narrow backfill cases. In view of this, this study establishes a modified analytical model for the passive earth pressure of narrow backfill behind a retaining wall under unsaturated steady-state seepage conditions, based on the log-spiral failure mechanism and the arched differential element method. The distribution, total force magnitude, and the height of the application point of passive earth pressure for narrow backfill under the ro...
