圧密理論の検討及び定圧圧密における歪み硬化・回復過程の導入

Abstract

We noticed that the boundary condition on the top surface of the consolidated bed in the theoretical calculations was incorrectly imposed in ref.1) and ref.2). Revised calculations are presented in this paper. In ref.1) a new theory for the constant load consolidation was proposed together with a convenient boundary conditions on the bottom of the consolidated bed (Eq. (7) in this paper) which assumed that the void ratio suddenly jumped to the final value immediately after the loading. If strict forward consideration is assumed, the boundry condition (BC) should be varied with time according to the increases in friction and particle network stress, i. e., Eq. (8) has to be imposed in place of Eq. (7). However, the previous calculations together with Eq. (7) predicted the observed consolidation curves even until middle of the consolidation period. To overcome this contradiction is the main objective of this work. Variable load consolidation experiments are compared with theoretical calculations for both BC's. Calculations for frictionless wall on the constant load are also conducted and discussed. It is concluded from these examinations that during the constant load consolidation the stress hardening must occur after the loading to balance out the extra load until strain in the bed reaches to a normal stressstrain relation, since strain could develop only when dewatering from the bed has progressed. Modified theory including the stress hardening and recovery process predicts consolidation experiments quite well for the whole period of the consolidation. Master curves for the constant load and the variable load consolidations are also presented.