DYNAMIC-TRIAXIAL CUMULATIVE DEFORMATION CHARACTERISTICS OF MUNICIPAL SLUDGE SOLIDIFIED SOIL UNDER THE COUPLING ACTION OF DRY-WET CYCLE AND INITIAL STATIC DEVIATOR STRESS

As subgrade filler,municipal sludge solidified soil is of great significance for saving engineering cost and protecting environment. This paper takes the municipal sludge solidified soil as the research object and uses DDS dynamic triaxial apparatus to study the influence on cumulative plastic strain and dynamic strength characteristics. It considers the three aspects of number of dry and wet cycles,initial static deviator stress and dynamic stress. The experimental results show that the accumulative plastic strain of soil increases first and then becomes stable with the increase of dry-wet cycles under the action of dry-wet cycles alone,but the change of accumulative plastic strain of soil is not obvious under the coupling action of dry-wet cycle and initial static deviator stress. The dynamic stress has a great influence on the cumulative plastic strain and there is a critical value. when the dynamic stress is less than the critical value. The cumulative plastic strain increases first and then becomes stable gradually. When the dynamic stress is greater than the critical value,the cumulative plastic strain increases rapidly after reaching a certain vibration time,which causes rapid deformation and damage of soil. Both the dry-wet cycle and the initial static deviator stress can reduce the dynamic strength of soil. But after the dry-wet cycle reaches 10 times,the dynamic strength can tend to be stable and not be affected by them. By means of regression analysis,we establish a stable cumulative plastic strain model of the municipal sludge solidified soil,which takes into account the influences of the number of dry-wet cycles,the initial static deviator stress and the dynamic stress. We verify its feasibility.