一维大变形主、次固结耦合新模型

A novel coupling model for 1D finite-strain primary-secondary consolidation

针对传统一维大变形固结理论不能考虑土体次固结变形的缺点,在连续介质力学有限变形理论和土力学固结理论基础上,提出了全新的一维大变形主、次固结耦合模型。该模型采用超静孔压为控制变量,可以分别表述为欧拉坐标、拉格朗日坐标和固相体积坐标等三种形式,其中均可以显式地反映出土体重度变化、固相速度、地表沉降速度、地下水位变化、荷载变化和次固结等6个因素的影响。在不同简化条件下,新模型可以分别退化为以往学者提出的相关模型。当不考虑次固结效应时,新模型与经典的Gibson大变形固结模型完全等价。从便于工程应用的角度而言,新模型中仅考虑次固结和外荷载变化的退化形式更便于求解,可作为一种供参考的实用模型。

Aimed at the weakness of ignorance of secondary consolidation in traditional 1D finite-strain consolidation theory,a novel coupling model for 1D finite-strain primary-secondary consolidation was presented,according to both the finite deformation theory in continuum mechanics and the consolidation theory in soil mechanics.Using excess pore water pressure as governing variable,the presented model could be formulated respectively with Eulerian,Lagrangian,and solid volume coordinates.Such factors as the change of unit weight of soil,solid phase velocity,settlement rate of ground surface,change of ground water table,change of surcharge and secondary consolidation,are explicitly expressed in the presented coupling model.Under different conditions,the new model could be reduced correspondingly to related models by previous authors.When taking no account of the secondary consolidation effects,the presented model is equivalent to that by Gibson et al.（1967）.From viewpoint of engineering convenience,the simplified form of the presented model considering secondary consolidation and the change of surcharge keeps more easily to be solved,and provides a practical model for further reference.