Effect of creep and destructuration under Sebou high speed railway line embankment

Special Laboratory Testing Method for Evaluation Particle Breakage of Railway Ballast Material

“…-the maximum limit of Los Angeles abrasion in Brazil is 40%, in Australia is 25%, in Canada is 20% [47], the difference between the European ones and mentioned ones is very high, -the water permeability values of the examined samples were 6.11×10 -1 cm/s connected to special Los Angeles abrasion tests with 250, 500, 750 and 1000 revolutions, respectively [47]; the value for normal, relatively clean ballast is 3×10 1 cm/s [47], -the higher the deterioration of the sample, the lower the cohesion, but it doesn't affect the inner friction angle [29], -the load bearing capacity values of both the new and the recycled ballast samples depend on the initial breakage [29], -the cohesion of ballast samples was approximately zero after 800 revolutions in the Los Angeles drum [29], -to assess the load bearing capacity of the mixed railway ballast sample (30% new + 70% re-cycled) is nearly the same as 100% new ballast sample [29], -angularity breakage signifies the break-off of the edges and corners of grains that arises at lower stresses [37], -confining stress plays a relevant role in the particle degradation, the larger the confining stress, the larger the breakage [37], -the connection between confining stress and deviator stress is linear [37], -the larger the confining stress, the larger the dilation angle (ψ) [37], -at low confining stress levels the dilation is significant larger [37], -the grain breakage develops first at the top and the bottom surfaces of the ballast samples during monotonic triaxial tests in the lab [37], -the PSD of ballast is able to be defined with 70% accuracy by GPR [4], -using of thermodynamically consistent hypoplastic model is suitable for assess of ballast degradation, the easy tractability is the benefit of this calculation method [6], -the examination of the interface of half depth ballast and half depth sub-ballast layer was performed by cyclic triaxial test in the lab, this interface reducts the axial and volumetric deformations at the interface region [8] that will stop in case the initial compactness and the confining stress raise [8],…”