考虑基岩软化和软土蠕变的桩基分析  

Analysis of Pile Foundation Considering Bedrock Softening and Soft Soil Creep

作　　者：李诚 LI Cheng(Guangdong Provincial Academy of Building Research Group Co.,Ltd.Guangzhou 510630,China)

机构地区：[1]广东省建筑科学研究院集团股份有限公司,广州510630

出　　处：《广东土木与建筑》2023年第9期19-22,共4页Guangdong Architecture Civil Engineering

摘　　要：为了研究桩基在基岩软化和软土蠕变作用下的受力情况,本文使用PLAXIS软件建立有限元模型,模型中软土的应力应变关系选用软土蠕变模型,强风化花岗岩的应力应变关系选用Hoek-Brown模型,介绍了在上软土下硬土二元地层中桩基承载力影响因素,在此基础上确定了建模方法和参数取值。有限元模型计算结果表明,软土蠕变对桩产生负摩阻力,对于抗剪强度差的软土而言,负摩阻力很早发挥出来并维持稳定,强风化花岗岩软化至一定程度后,引起桩基沉降快速增大,继而导致不均匀沉降快速发展,最终引起结构的突发拉裂破坏。In order to study the stress of pile foundation under the condition of bedrock softening and soft soil creep,uses PLAXIS soft-ware to establish a finite element model.The stress-strain relationship of soft soil in the model selects the soft soil creep model,and the stress-strain relationship of strongly weathered granite selects the Hoek-Brown model.Introduces the factors affecting the bearing capacity of pile foundation in the binary stratum,which's upper layer is soft soil and the lower layer is hard soil,and determines the modeling method and parameter values.The calculation results of the finite element model show that the creep of soft soil produces negative friction on the pile.For the soft soil with poor shear strength,the negative friction develops very early and remains stable.After the strongly weathered granite softens to a certain extent,the settlement of the pile foundation increases rapidly,and then leads to the rapid development of uneven settlement,and finally causes the sudden destruction of the structure.

关 键 词：软土 强风化花岗岩 桩基 有限元分析 

分 类 号：TU473.1[建筑科学—结构工程]