FHWA - Circular No4 Reese-Wang Eqns
FHWA - Circular No4 Reese-Wang Eqns
(OP)
In Appendix A and Appendix B the Wang-Reese equations are used and shown in a spreadsheet format. I have 2 questions pertaining to the Passive resistance for sands spreadsheet in appendix B:
1. How is the Total Passive Force Calculated? I thought it was the d/2 (toe depth) x Min. Passive Resistance but I think I'm missing something.
2. They set d=h1 and alpha=0 in to solve eqn B-2. What is h1? I thought it might be the depth of toe below the excavation minus di, but I wasn't sure.
Thanks.
1. How is the Total Passive Force Calculated? I thought it was the d/2 (toe depth) x Min. Passive Resistance but I think I'm missing something.
2. They set d=h1 and alpha=0 in to solve eqn B-2. What is h1? I thought it might be the depth of toe below the excavation minus di, but I wasn't sure.
Thanks.
EIT





RE: FHWA - Circular No4 Reese-Wang Eqns
I spent just a few moments looking at the Appendix in question, but here goes:
This is how I do it:
Select d.
Check to make sure that Ppu by Eq B-5 is more than Ppu by Eq B-2.
Compute Fp by Eq B-1, subtract Fp computed for d = di, b=0, if di > 0.
Check to make sure this value is less than that for a continuous wall.
For LRFD, factor and compare with the active earth FORCE.
The spreadsheet presented may be performing an integration over d to determine the total resistance.
Hope this helps.
J
RE: FHWA - Circular No4 Reese-Wang Eqns
Atleast I can complete the spreadsheet now. We have some software and I made a different spreadsheet using the Cali Trenching and Shoring manual but I wanted to compare the results with this manual.
One question,
When you compute Fp with d=di and b=0 are you using Eq B-1?
Thanks
EIT
RE: FHWA - Circular No4 Reese-Wang Eqns
J
RE: FHWA - Circular No4 Reese-Wang Eqns
EIT
RE: FHWA - Circular No4 Reese-Wang Eqns
the problem is that it is not h1, (h1 = d-d1 ?????), if the response does not give me the values shown in the example that appears in the document.
Thank you in advance for helping
Greetings
piltomania
RE: FHWA - Circular No4 Reese-Wang Eqns
now I have problems with the column "Total Passive Force (WR)"
and I guess it must be calculated with Eq-B-1, but
values are not entirely reliable.
I would like someone to tell me if this equation is solved or
another, or must be supplemented with something special.
in advance thank you very much
piltomania
RE: FHWA - Circular No4 Reese-Wang Eqns
EIT
RE: FHWA - Circular No4 Reese-Wang Eqns
also know that eh had trouble figuring FACTOR SECURITY
WANG-REESE(SANDS), as I step by step example of the rule and not give me those results.
I think the safety factor should be calculated as:
FS = (Minimum Wang-Reese Passive Resistance) / (Rload)
where Rload = (Toe reaction)X(separation between profiles)
I hope your help
piltomania