Page 278 - 360.revista de Alta Velocidad - Nº 5

Álvarez, Fernando. Balmaseda, Lucía. Gallego, Inmaculada. Rivas , Ana. Sánchez-Cambronero, San

1. Firstly, it is verified that by making the Subballast stiffen by increasing the value of its
friction angle (Models #7 and #8), it leads to a greater stress absorption and, therefore,
the stress profile moves to the right, towards higher stress values.
2. With regard to the Formation layer:
- If it has a friction angle of 35° constant and the Subballast of 35° (Model #4) and it
changes to 45° (Model #7), the differences in the vertical stress level are negligible.
- In the same way, it happens in the case of having a constant value 20° in the Formation
layer of form and to re-vary that of the Subballast (Models #6 and #8).
3. On the other hand, a constant value of the internal friction angle of 35° in the Subballast
and with a variation in the Formation layer (Models #4 and #6) makes a significant influence
of vertical stress difference in the layers of Ballast and Subballast. The same occurs when a
constant value of friction angle is set in the Subballast of 45° and the shape layer (Models
#7 and #8) varies with the same difference of vertical stresses in the two upper layers.
4. In the contact Formation layer-Embankment at the height of 1.5 m. it is observed that the
vertical stresses are equal for all elastoplastic models until reaching the 0 or base of the
model.

Fig. 7. Profile of vertical stresses due to the application of the railway load for all the models studied.

276 360.revista de alta velocidad