摘要
针对软基拼宽及地铁施工扰动引起邻近既有桥梁桩基病害的实际工程问题,在FLAC^(3D)软件中建立三维模型,充分考虑软土的蠕变特性和桩土间的相互作用,采用黏弹塑性Cvisc本构模型模拟各近接工程施工及桩基病害发展的全过程.在与现场实测数据对比验证后,进一步分析在不同施工工况下桩身位移与内力的响应,定量判断桥梁桩基桩身的病害情况,为后续加固设计提拱依据.计算结果表明,病害的主要原因是软基拼宽后引起淤泥层长时间的水平向蠕变,使邻近刚性桩上水平推力大增,最终导致破坏.结合工后变形尚未稳定且桥梁桩基紧邻地铁隧道的实际情况,提出桩基主动托换的病害整治方案,并进行数值模拟.
A three-dimensional model was established in FLAC^(3 D) to solve the practical engineering problems of bridge pile foundation diseases caused by subgrade widening on soft ground and subway construction.The creep characteristics of soft soil and the interaction between pile and soil were fully considered in the model.The viscoelastic plastic constitutive Cvisc was used to simulate the whole process of the construction and the development of pile foundation diseases.After verifying the calculation results with field measured data,the displacement and internal force responses of piles under different construction conditions were further analyzed.The damage of bridge pile foundation was judged quantitatively,which provided the basis for the subsequent reinforcement design.The calculation results show that the main cause of the disease is the long-time horizontal creep of the silt after the subgrade is widened,and the subsequent disturbance of the metro tunnel construction further aggravates the deformation,which increases the horizontal thrust on the adjacent rigid piles and finally leads to the failure.Furthermore,combined with the actual situation,a pile underpinning treatment scheme was proposed,and the corresponding numerical simulation was carried out.
作者
缪圆冰
陈礼榕
郑路
林聪煜
MIAO Yuanbing;CHEN Lirong;ZHENG Lu;LIN Congyu(College of Civil Engineering,Fuzhou University,Fuzhou,Fujian 350108,China;Fujian Luhai Engineering Survey and Design Co.,Ltd.,Fuzhou,Fujian 350007,China;Institute for Disaster Management and Reconstruction,Sichuan University,Chengdu,Sichuan 610065,China;College of Civil Engineering,Hunan University,Changsha,Hunan 410082,China)
出处
《福州大学学报（自然科学版）》
CAS
北大核心
2022年第3期431-438,共8页
Journal of Fuzhou University(Natural Science Edition)
基金
国家自然科学基金资助项目(41977233)
国家重点研发计划项目(2017YFC1501001)。
关键词
软土地基
路基拼宽
Cvisc蠕变模型
桩基
数值模拟
soft ground
subgrade widening
Cvisc creep model
pile foundation
numerical simulation
