Abstract
In urban areas with extensive peat ground, such as Sapporo, long-term subsidence of shallow buried structures such as backfilled pipelines has been reported to pose chronic engineering problems. In addition to natural ground water fluctuations, pavement overlaying and nearby traffic loads, the load imbalance due to backfilling itself is suspected to aggravate the problem, as the usually very light peat is replaced by heavier, compacted sandy fills. The objective of this paper is to discuss detailed mechanisms behind the subsidence observed in surface peat layers. In this study, subsidence mechanisms are investigated by performing long-term 2-D model tests and soil-water-coupled finite element (FE) analysis using a Modified Cam Clay-type model tuned to express the stiffness and consolidation characteristics peculiar to peats.
