Bearing characteristics of prestressed sheet pile wall in embankment stablization

Based on the reinforcement project of k70 embankment along Kunming-Bangkok Expressway, the bearing characteristics of prestressed sheet pile wall in embankment stabilization are studied through a series of in-situ tests. The history of pile displacement, earth pressure, bending moment and prestress of cables are measured and used to illustrate the bearing characteristics and behaviors of the structure. The measured results show that the prestressed sheet pile wall significantly increases the stability of the embankment, and that the structural displacement increases linearly with the height of embankment at the beginning of backfill and then slows down with the construction of cables. The pile flexure rather than pile rotation becomes increasingly prevalent with the increasing height of filling embankment. The distribution of earth pressures exerting against the pile is triangular and that on the face of plate is parabolic. The earth pressures against the pile are systematically larger than those of plate at the same depth, which results from arching effects. The maximum value of earth pressures of the pile is close to the thrust, while the maximum value of the plate is close to the active earth pressure. Analysis of the piles using the simple elastic analysis gives that the bending moments and displacements are close to the measured ones. The test results also indicate that the percentage of loss for cables is about 10% in the short term and 12%~15% in the long term.