Hi,
Can I know what parameter can I adjust to increase the strength of a fill material? With the conditions that saturated unit weight, dry unit weight, cohesion and friction angle have to be fixed.
Thank you
Hi Patrick,
If u want to increase the strength of the soil you need to adjust the strength parameters cohesion (c) and friction angle (phi). Normally in slope failure resisting force is needed to be greater than the driving force where resisting force is described by the shear strength of the soil which is given by shear strength= c +( normal force * tan (phi)).
Thanks.
Dear Nitha,
Thank you so much for your help.
Best Regards,
Patrick
Dear Patrick,
If, as you mention, it's not possible to change the cohesion and friction angle the only way to increase the strength is by increasing the effective stress level. Since you can not change the soil unit weights either there are only 2 possibilities left:
1) A small effect may be achieved by introducing some dilatancy in the material
2) A larger increase of strength can be achieved by considering the fill material as unsaturated material, hence allow of matric suction.
If you fill material is not dilatant or either dry or fully saturated then there is no other way to increase the strength but to increase cohesion and friction angle as Nitha already mentioned.
With kind regards,
Dennis Waterman