長樁模型於飽和粉土質砂土中之樁土互制反應

Due to the thick silty soil layers and seismic effects in the western sea floor of Taiwan, group pile foundations are preferred for offshore wind turbine foundations. Because of the high uncertainties and complexities of soil-pile interactions in laterally loading conditions, the needs for proper understanding the soil-pile interactions in silty soils have raised. This paper presents the results of long pile push-over tests in a saturated silty sand under different stress conditions. A layered calibration chamber for CPT study is converted to apply compensated boundary stresses during the push-over phase to reduce the boundary effects in model tests. A model pile with bending strain gauges and tactile sensors for interface stress monitoring are embedded in the field simulator and lateral loads are applied on the pile top with different constrained conditions. The results reveal that the typical p-y curves for sand and clay are not applicable to local silty soils. The p-factor reduction from the sand curve should consider the field stress conditions and the compressibility of silty sand.