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Adachi-Oka蠕变模型参数敏感性分析

李刚,张金利,刘伽,何世丹   

  • 出版日期:2018-02-28 发布日期:2018-02-28

Sensitivity analysis on parameters of Adachi-Oka model

LI Gang, ZHANG Jinli, LIU Jia, HE Shidan   

  • Online:2018-02-28 Published:2018-02-28

摘要: 为了研究蠕变模型参数的敏感性,基于Adachi-Oka屈服面蠕变模型,通过对软黏土地基的固结计算,分析了本构参数对计算结果的影响。研究结果表明:至计算完成时(1 a后),地基土体的沉降随着土层深度的增加而减小,超孔压随着土层深度的增加而增大,荷载作用区右侧区域出现了“反拱”现象。参数敏感性分析表明,对沉降影响较大的参数是临界应力比、弹性剪切模量、压缩指数及黏塑性参数,其中以临界应力比对计算结果最为敏感。建议在进行位移反分析时,重点对上述参数进行调整,其余参数可以通过经验或相关规范取值。

关键词: Adachi-Oka模型, 蠕变, 固结, 软黏土, 沉降, 超孔隙水压

Abstract: In order to study the sensitivity of the Adachi-Oka model parameters, the numerical simulation is carried out to study the effects of model parameters on settlement. The results show that the foundation settlement decreases with increase of soil depth, and excess pore water increases with the depth. The invert arch phenomenon occurs on the right area of the loading area. By changing the parameters, a large quantity of numerical analysis show that stress ratio at failure, elastic shear modulus, compression index and viscoplastic parameter have great effects on the settlement, and the stress ratio at failure is the most sensitive. It is suggested that we should give priority to the above parameters, and the other parameters can be obtained by experience or relevant codes in back analysis of displacement.

Key words: Adachi-Oka model, creep, consolidation, soft clay, settlement, excess pore water pressure