淤泥软土深基坑有限元模拟计算  

Finite Element Simulation Calculation of Deep Foundation Pit in Silt Soft Soil

作　　者：李伟 LI Wei(Hubei Province Wantai Geotechnical Investigation and Design Company,Yichang 443000,China)

机构地区：[1]湖北万泰岩土勘察设计有限公司,湖北宜昌443000

出　　处：《广东土木与建筑》2022年第10期27-30,共4页Guangdong Architecture Civil Engineering

摘　　要：当开挖地层范围内存在淤泥软土时,深基坑开挖的变形需要引起重视。对福州某深基坑工程开展有限元模拟,根据计算结果,分析了不同工况下支护结构的变形和受力、周围地表沉降、基坑坑内隆起等分布规律。在淤泥软土深基坑,支撑梁面的标高确定十分重要,合理的布置内支撑梁数量和间距,可显著减小围护结构的最大变形值。结果表明:基坑在不同工况下,随开挖深度的增加,第n+1道支撑梁的变形、轴力明显比第n道支撑梁大;第n+1道支撑梁的剪力比第n道支撑梁小;随着开挖深度加深,基坑坑底的隆起变形值逐渐增大;围护桩的最大位移值和弯矩值随开挖深度增加逐渐增大。施工支撑梁后,桩身最大位移和弯矩位于最下面一道内支撑和坑底的腰腹部位。基坑阳角部位和长跨度边的中间部位的变形最大,基坑的最大隆起变形主要发生基坑中部,距离围护桩越近,隆起变形值越小。When there is silt and soft soil in the excavated stratum,the deformation of deep foundation pit excavation needs to be paid attention to.The finite element simulation of a deep foundation pit project in Fuzhou City is carried out.According to the calculation results,the distribution laws of the deformation and stress of the supporting structure,the surrounding surface settlement and the uplift in the foundation pit under different working conditions are analyzed.It is very important to determine the elevation of the support beam surface in the deep foundation pit in silt and soft soil.Reasonable arrangement of the number and spacing of the internal support beams can significantly reduce the maximum deformation of the retaining structure.The results show that the deformation and axial force of the n+1 support beam are obviously larger than that of the n support beam with the increase of excavation depth under different working conditions;The shear force of the n+1 supporting beam is smaller than that of the n supporting beam;With the deepening of excavation depth,the heave deformation value of foundation pit bottom increases gradually;The maximum displacement and bending moment of retaining piles increase with the increase of excavation depth.After the construction of the support beam,the maximum displacement and bending moment of the pile body are located at the waist and abdomen of the lowest inner support and the pit bottom.The deformation of the external corner of the foundation pit and the middle part of the long span side is the largest.The maximum uplift deformation of the foundation pit mainly occurs in the middle of the foundation pit.The closer to the retaining pile,the smaller the uplift deformation value.

关 键 词：软土深基坑 有限元 最大变形值 支护结构 

分 类 号：TU753[建筑科学—建筑技术科学]