ANALYSIS OF THE TRAFFIC LOAD–INDUCED STRESSES OF EMBANKMENT

This article represents traffic loads on the road structure distribution and evaluation of the vertical and horizontal stresses formation in the soil embankment. This evaluation allows to predict the depth and intensity of the propagation of additional stresses resulting from traffic loads. The calculations were performed in accordance with four normative documents applied in Lithuania, which define the loads on the road structure. The obtained results showed that the area to which the load is distributed has the greatest influence on the intensity of stresses and the distance of propagation. The maximum horizontal stress in the embankment was found to be no more than 70 kPa and the maximum stress propagation depth did not exceed 0.9 m. The results can be applied to a triaxial test apparatus to restore horizontal stresses in the embankment. It is recommended to select a lateral pressure from 20 kPa to 70 kPa for tests provided with triaxial test device. The mechanical properties of the soil determined with triaxial test device and recommended lateral pressure would be representative of the test results obtained in the field of embankment.

Dynamic Triaxial Test and Microscopic Study of Solidified Muddy Soil With Different Mixing Ratios and Curing Ages

Aiming to explore the optimal mixture ratio and curing age of solidified muddy soil under dynamic load, the paper intends to investigate whether the solidified muddy soil can be used as filling of high-speed railway subgrade. Based on the dynamic triaxial test, the investigation measured the dynamic strain and dynamic elastic modulus of solidified muddy soil under different mix ratios and curing ages, and also observed the microscopic morphology of solidified muddy soil samples by using scanning electron microscope. The results show that the addition of cement and curing agent significantly increases the dynamic strength and elastic modulus of muddy soil, which effectively improve the dynamic characteristics of muddy soil. The curing effect of the curing agent is more obvious with the increase of the dosage of cement and curing agent under different mix ratio. The content of curing agent plays a leading role in the hydration reaction between cement, curing agent and soil particles. Additionally, in case of the same test conditions, when the ratio of cement mass to dry silt mass is 1:20, the ratio of diluent volume to dry silt mass is 1:20, with 28 days of curing age, its curing effect will reach the best.