Performance of Sheet Pile Wall in Peat

Abstract

To study the performance of sheet pile wall in peat during roadway construction, a long-term instrumentation program was conducted over a period of two years, measuring total lateral earth pressures, sheet pile deflections, soil movements, and water table level variances during construction. The analysis of field data indicated: (1) The earth pressure distribution in peat matched well with the classic Rankine earth pressure; (2) the expected long-term postconstruction sheet pile movement due to the creep behavior of peat was not observed; (3) fully passive earth pressure in peat was mobilized once the maximum measured sheet pile deflection exceeded 0.8% of sheet pile length; and (4) arching effect due to the protruding cross section of sheet pile caused pressure differences of 3–10kPa between the inside web and outside web of the sheeting. Then, all the construction stages were continuously modeled by finite-element method and the calculated results were compared with the field measurements. The comparisons showed that the calculated results were consistent with the field data and provided reasonable explanations and helpful insights to understand soil–structure interaction mechanism. Finally, some conclusions and suggestions for sheet pile design and construction in peat were reached.