Study On Consolidation Characteristic Of Remoulded Soft Clay

Consolidation preoerties is an important subject of soil mechanics and the basis of soil compressibility and settlement prediction.This paper focuses on the conslolidation properties of remolded soil and mainly studies the effect of initial content on it and that in low consolidation pressure by a serial of oedometer tests with soil samples from different areas and with different initial water contents.The results extend the knowledge of consolidation properties of remolded soil.The main work of this paper consists of the following aspects.(1)improve the conventional oedometer,so that it can be applied with both small loads and conventional loads range from 1.5kPa to 1600 kPa.A series of unidirectional consolidation compression tests have been performed on four kinds of soil samples from Lianyungang and Tanggu of Tianjin with the initial water content range from 0.7wL to 2.0wL.(2)study the effect of water content on the consolidation index of remolded soil and the relationship between the consolidation load and consolidation index.The compression index increases with the increase of consolidation load,and then slightly declines,the greater the water content,the greater the extent of decline;the compression index with the stress interval of 200 kPa ~ 1600 kPa increases in the hyperbolic curve with the increase of water content;the compression coefficient of the first stage of consolidation load action increases in the power function with the increase of initial water content.(3)In the stage of small consolidation pressure,the compression index increases linearly with the increase of load.The compression index value in the stress interval of 0 ~ 12.5kPa increases linearly with the increase of initial water content.(4)There exists a remolded yield pressure in the e-lgP compression curve of the remodeling soil which is similar in nature to the pre-consolidation pressure of undisturbed soil,and the remolded yield pressure decreases in power function with the increase of water content.(5)study the effect of water content and consolidation load on the consolidation coefficient,especially in the small consolidation pressure stage.The consolidation coefficient increases with the increase of the water content;and it first decreases rapidly and then increases with the increase of consolidation load.The differences between the time square root method and the time log method in calculating the consolidation coefficient have been studied,and the value calculated by the time square root method is greater than that got by from the time logarithm method.(6)study the effect of the initial water content and consolidation load on the secondary consolidation coefficient.The secondary consolidation coefficient first increases and then decreases with the increase of consolidation load,and the greater the initial water content,the greater the extent of the decline;in the small consolidation pressure stage,the secondary consolidation coefficient increases linearly with the increase of load;and the greater the initial moisture content,the greater the secondary consolidation coefficient.