一维小变形主、次固结耦合理论模型分析  

Study of coupling theory of one-dimensional small-strain primary and secondary consolidation model

作　　者：仇玉良[1] 丁洲祥[1,2] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221008

出　　处：《岩土力学》2012年第7期1957-1964,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.50708077;No.41172221);中央高校基本科研业务费专项资金资助(No.2011JBM264);深部岩土力学与地下工程国家重点实验室资助项目(No.SKLGDUE08007X)

摘　　要：基于丁洲祥等提出的大变形主、次固结耦合模型,研究了在小变形情况下退化的主、次固结耦合模型。首先对该模型进行了无量纲化处理,引入了新的主、次固结耦合系数Cs c。当Cs c=0时,模型即退化为经典的Terzaghi固结模型。采用有限差分法分析了新模型中超静孔压的变化规律发现,当主、次固结耦合系数Cs c>0时,固结初期的超静孔压出现类似Mandel效应的增大现象,并且Cs c值越大,这种现象愈加明显;Terzaghi主固结理论预测的超静孔压值一般会偏小于考虑主、次固结耦合情况下的结果。上述现象区别于Mandel效应的本质原因在于主、次固结耦合效应,这与殷建华等的EVP模型较早论述的黏性效应本质是一致的,但本文模型的表述相对而言更为简洁。最后结合Mesri和Godlewski的cCα/C概念,提出了Cs c的确定方法及模型的改进形式,其结果为主、次固结耦合理论的深入研究和工程应用提供了新的参考。Based on the finite-strain coupling model of primary-secondary consolidation proposed by Ding et al.,a reduced small-strain coupling model is investigated with dimensionless analysis method.A new coupling coefficient of primary-secondary consolidation,,is introduced into the reduced model.For the case of,the model could be equivalent to classic Terzaghi’s consolidation model.Finite difference method is used to analyze the variation of excess pore pressure predicted with the proposed model.The results show that：（1） when is greater than zero,the excess pore pressure at early stage of consolidation increases with the development of time especially for higher values of,which is similar to Mandel effect;（2） values of excess pore pressure predicted by Terzaghi’s primary consolidation theory are generally less than those by the proposed coupling model.The mechanism of the above phenomenon lies in the coupling effect of primary and secondary consolidation,which is analogous to the viscous effect using EVP model by Yin et al.According to the concept firstly presented by Mesri ＆ Godlewski,a method to determine the value of for a given soil is put forward as well as a modified small-strain coupling model utilizing the concept.The presented coupling model can provide new and good reference with its simplicity and convenience for further study of primary-secondary coupling mechanism with application to engineering practice.

关 键 词：主固结 次固结 耦合 小变形 超静孔压 

分 类 号：TU433[建筑科学—岩土工程]