Study on Dynamic Characteristics of Over-Wet Loess Modified by Red Mud Under Cyclic Loading
A great amount of red mud waste in the world urgently need to be solved. In order to explore the effect of red mud modified over-wet loess, the cyclic loading test was carried out by the GDS dynamic three axis system. The dynamic stress-strain relations, accumulated plastic strain, dynamic modulus and damping ratio of the modified soil are analyzed, which also are compared with unmodified loess. The results show that the addition of red mud can effectively ameliorate over-wet loess, improving the bearing capacity and the ability to resist deformation. The cumulative plastic strain increases with the increase of the dynamic stress, yet decreases with the increase of confining pressure. It shows different development trends with the increase of dynamic strain: stable type and failure type, and the critical dynamic stress of the modified soil is higher than the measured maximum dynamic stress of subgrade. With the dynamic strain increases, the dynamic elastic modulus increases first and then decreases, but damping ratio slightly decreases first and then increases. The dynamic modulus of modified soil is modified about 4 times than that of loess but damping ratio is lower. The modified soil has no leaching toxicity and good environmental effect. The research results provide a theoretical basis for red mud used in the improvement of over-wet soil or soft foundation.
KeywordsRed mud Over-wet loess Cumulative plastic strain Dynamic modulus Leaching toxicity
This study was financially supported by Scientific Research Foundation of Shanxi Province of China (201701D121121) and Shanxi Scholarship Council of China (2017-039).
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