大变形固结理论连续性条件的严格表述

A Strict Form of Continuity Condition in Largestrain Consolidation Theory

基于连续介质力学有限变形理论,提出了欧拉描述情况下,一维大变形固结连续性条件的严格表述形式.其中,控制变量分别选择常用的Almansi应变和孔隙比两种情况.分析结果表明,以往根据简化形式的连续性条件得到的Almansi应变及其物质时间导数的计算值均偏小,容易导致对地基沉降变形的估计不足.传统分析中将Almansi应变的物质导数直接用作土体瞬时体积变化率,这种度量方法理论上应当予以修正.

Based on finite deformation theory of continuum mechanics, a strict form of continuity condition for onedimensional large-strain consolidation problems is proposed in terms of Eulerian description. The usual governing variables such as Almansi strain and void ratio are discussed respectively to establish a new strict form of continuity condition. The results show that the conventional simplified continuity condition can predict smaller values of both Almansi strain and its material time derivative, thus leading to a considerable underestimate of foundation settlement. It＇s necessary to modify the conventional method of taking material derivative of Almansi strain directly as instantaneous rate of volume change of soil mass.