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作者单位
许崇华 南京大学地球科学与工程学院 
摘要:
      依托某储油罐的碎石桩复合地基处理实例,进行了复合地基现场变形、荷载传递及固结速率的长期监测。参照工程实际建立了碎石桩复合地基三维有限元水土耦合分析模型,讨论了碎石桩桩长以及复合地基置换率对碎石桩复合地基工程性状的影响。监测结果和有限元数值分析结果表明:碎石桩复合地基对于沉降和水平位移的控制效果较好,保证了施工过程中地基的稳定性;随着上部荷载的增加,桩土应力比逐渐增大。碎石桩给地基提供了良好的排水通道,有效加快了地基的固结速率;碎石桩复合地基沉降随着桩长和置换率的增加而减小,但达到一定程度时,置换率和桩长对沉降的减少效果有限;复合地基桩土应力比随着桩长的增加而增大,随着置换率的增大而减小;置换率和桩长的增加都能加快碎石桩复合地基的固结速率,但是置换率对固结速率的影响更大一些
关键词:碎石桩  复合地基  荷载传递  沉降  固结
Abstract:
      Based on a case study of composite foundation by gravel pile of a oil tank, the author conducted monitoring on site deformation, load transfer and consolidation rate for composite foundations, set up a 3D water-soil coupling finite element analysis model (FEM) in accordance with the project, discussed the influence of gravel pile length and replacement ratio of the composite foundations on the engineering characters of the composite foundations. The detection results and numerical analysis results of finite element showed that the gravel pile could effectively reduce the settlement and horizontal displacement of soft ground. The pile-soil stress ratio increases with the increasing upper load. The stone columns provide drainage channels and accelerate the consolidation rate. The settlement decreases with the increasing replacement ratio and pile length. However, the effect became limited when the replacement ratio and pile length reached some value; the soil-pile stress ratio increased with the increase of pile length or the decrease of replacement ratio. The increase of pile length and displacement ratio could accelerate the consolidation rate of composite ground, and replacement ratio had more influence on the consolidation rate than pile length.
Keywords:Gravel pile  Composite foundation  Load transfer  Settlement  Consolidation
许崇华.碎石桩复合地基现场试验及数值模拟分析[J].地质学刊,2013,37(4):668-674