When we use the shear strength reduction method (SSR) in stability analysis of slope with nail supporting, how do you consider the change of stress of a nail during the SSR applied?
I have not considered such a problem. However, I do not think that the strength parameter of soil nails, i.e., tension stress, should be reduced during SSR.
I agree with Hong Zheng.
A soil nail has a permanent axial load capacity abilability law defined by bolthead and rod capacity, and strength developed between soil and rod. However, if the soil-rod interaction is dependant of friction (and cohesion as well) of the soil, you obviously should modify the tenslie capacity law along the nail (if the program does not do it). Otherwide, if the soil-rod strength is ensured independently of the friction angle of the soil you don't need do any more during your computation.
Thanks a lot for Prof.Zheng and David's answers. You really help me consider deeply about this problem.
In SSR, for the simple plane slide, (c/k+sigma*tan(phi)) /T=1-------(1), where T is the sliding force.
If the nail axial force is applied, then the equation should be tranferd to (c/k+(sigma+sigma1)*tan(phi)) /(T-T1)=1--------(2), where sigma1 and T1 is the normal force and anti-force induced by nail. Then if the nail axial force changed during the SSR applied, the equation (2) will no longer be true.
- Badges
- Science topic
- Similar topics
- Geoscience
- Asia
- India