Fac in CAESAR II

[lucas2008]

I am doing a analysis for the underground pipeline and I have few soil data.
I will use the following soil data:

friction angle : 27
density: 1.8 kg/m3
coeff. friction: 0.2
Soil : sand
OCM:6

I specified
ALLOWABLE STRESSES
B31.4 (2002) Eff= 1.0000 Sy= 241,316 KPa Fac= .5

I need to know what is the common Fac used for ANSi B 31.4 allowable stresses.
I need to Know what is the common factor for the soil.
I want to Know what is the temperature change indicated in the soil data.

thanks and excuse me for my english. I write litlle english.

 

[richay]

If you're going to "bury" the model, leave FAC blank, CAESAR II will fill this in. "FAC" indicates the "degree of axail restraint" due to the soil. Check the "help text" on this item.

Richard Ay
COADE, Inc.

 

[lucas2008]

Thank richay for the answer.
I run the buried model with FAC blank, but in the CAESARS'Quick reference guide for B31.4 indicate:

1- If FAC = 1 (fully restrained pipe)
2- If FAC= 0.001 (buried, but soil restraints modeled)
3- If FAC=0.0 (fully above ground)

I use the case 2.

however, if I write FAC = 0.001 the program simulates a case with almost no restrictions on the ground.

If I leave FAC blank on the results in the code compliance indicate that dont done code compliance.
againb thanks.

 

[richay]

DO NOT PLAY with "fac" to get the job to pass, this is cheating. This is similar to reducing your tempeature to make a job pass.

As you stated above, you have 3 conditions. If you use the buried pipe modeler let CAESAR II set FAC and live with it. If you're overstressed change the piping layout.

Richard Ay
COADE, Inc.

 

[lucas2008]

Thanks richay.
This pipeline aren´t overstressed , but i want to make the calculation memory and i must to write this FAC.

the data in this memory.

Thanks again