滨海软土地基二次堆载预压固结沉降研究
Study on secondary preloading induced consolidation settlement of coastal soft soil foundation
辛全明 1佘小康 1孔志军 2蔡奇鹏 2汪智慧 1姚桂嘉3
作者信息
- 1. 中国建筑东北设计研究院有限公司,辽宁 沈阳 110000
- 2. 华侨大学 土木工程学院,福建 厦门 362021
- 3. 中建东设岩土工程有限公司,辽宁 沈阳 110000
- 折叠
摘要
滨海软土往往工程性质较差,一次堆载预压通常达不到设计要求而需要进行二次堆载预压.本文通过现场原位试验和室内试验,对二次堆载预压2年后的地基软土开展物理力学性质研究,并将试验获得的土体参数用于规范法和数值模拟,对地基未来 20 年的沉降进行预测.结果表明,二次堆载预压 2 年后,部分软土层力学参数提升显著,但淤泥层力学参数未见明显改善,地基承载力未达到设计要求,后续仍有较大的沉降变形.同时,对比规范法和研究开始前 18 个月沉降规律发现,经过二次堆载预压后的地基,数值模拟采用弹塑性模型能更准确地预测后续沉降,二次堆载预压20年后地基最大的沉降量可达1 m,位于12号钻孔位置处,其次是18号钻孔位置处,沉降量为0.9 m,10号钻孔位置处沉降量为0.8 m,并且沉降主要集中在淤泥层中.
Abstract
Coastal soft soil often exhibits poor engineering properties,with initial consolidation generally failing to meet design requirements,necessitating secondary consolidation.This paper investigates the physical and mechanical properties of foundation soft soil two years after secondary consolidation through in-situ and laboratory tests.The parameters obtained from the experiments are used in standardized methods and numerical simulations to predict the settlement of the foundation over the next 20 years.The results indicate that,two years after secondary preloading,there is a significant improvement in the mechanical parameters of some soft soil layers,while the mechanical properties of the silt layer show no obvious improvement.Consequently,the bearing capacity of the foundation has not met the design requirements,and substantial settlement deformation is expected to continue.Additionally,by comparing the settlement patterns from the 18 months prior to the study with the result from the method recommended by norm,it is found that numerical simulation using an elastoplastic model can more accurately predict subsequent settlement after secondary preloading.The maximum settlement after 20 years of secondary preloading is going to reach 1 m at No.12 borehole,followed by 0.9 m at No.18 borehole,and 0.8 m at No.10 borehole,with settlement mainly concentrated in the silt layer.
关键词
软土地基/二次堆载预压/规范法/数值模拟/沉降预测Key words
soft soil foundation/secondary preloading/method recommended by norm/numerical simulation/settlement prediction引用本文复制引用
基金项目
国家自然科学基金资助项目(52378342)
国家自然科学基金资助项目(52308400)
福建省科技计划项目(2022Y4015)
福厦泉国家自主创新示范区协同创新平台项目(3502ZCQXT2022002)
中建股份科技研发计划资助项目(CSCEC-2020-Z-57)
出版年
2024
NETL
NSTL
万方数据