hydrostatic pore pressure 1

[Anand478]

Hi everyone,

I am currently carrying out a study of the effect of rainfall on natural slopes for a dissertation, and the one outcome which I have considered is raising the GWL. I am studying various slope angles and heights and raising the GWL until a factor of safety of 1 is reached.

I have decided to choose zero pore pressure above GWL and hydrostatic below

I have a few disadvantages of these assumptions which I can discuss, I was wondering what everyone's view was on this in terms of disadvantages? and if anybody knows of similar studies?

Kind regards,

Anand

 

[BigH]

Anand478 - have you done any literature searches. There are many papers out that cover this topic.
1. The Influence of rainstorm pattern on shallow landside by Tung-Lin Tsai
2.

http://www.icevirtuallibrary.com/do...est&checksum=9F4FBD0EA0C96FDC848366EEC0C44D59

3.

http://rainfallthresholds.irpi.cnr.it/Article_MAP_r2v14_16nov2006.pdf

4.

http://www.nat-hazards-earth-syst-sci.net/12/829/2012/nhess-12-829-2012.pdf

5.

http://people.bu.edu/sergio/CV/papers pdf/2003-hollow-WR001595.pdf

6. Cornforth's Book - "Landslides in Practice" - Chapter 5 on groundwater and Chapter 9 on infinite slope analysis
7. Bromhead's Book - "The Stability of Slopes", 2nd Ed - Chapter/section 5.12 on infinite slope and Appendix E
8. Abramson et al Book - "Slope Stability and Stabilization Methods" - Chapter 3 on groundwater and Chapter 6 on analyses

I hope that the above gives you a start . . .

 

[killswitchengage]

First disadvantage is that you cannot put 0 PWP above GWL in clays , they usually have negative PWP which improve stability .
Your assumptions can only be used for coherent materials , other than that cohesionless materials only fail if the angle Beta is higher than the angle of friction of the soil independent of its height . Loose granular materials can liquefy in the presence of water too.
Some clayey material suffer from chemical alteration as well as seepage forces that you must add to PWP .