Manik_08ce
Structural
- Sep 25, 2024
- 1
Hi all,
FHWA Safety Factor for Cone Shear Failure in Concrete (ASD):
"Does the FHWA provide a recommended safety factor for concrete cone shear failure in ASD, particularly for micropile and anchor applications? I’ve come across a safety factor of 2.0 being used, but I’d like to confirm if this is in line with FHWA guidelines."
I will also ask for some additional guidance:
I calculated the nominal concrete cone shear strength based on ACI 349 B.11.2, as shown in the FHWA guidelines, and I arrived at the following value:
Dividing by a safety factor of 2.0 gives me an allowable cone shear capacity of 185k. However, the utilization ratio is 1.16 (greater than 1), meaning the demand exceeds this capacity. Some colleagues suggest ignoring the concrete capacity entirely and providing only anchor reinforcement, which would lead to a dense arrangement of reinforcement that would be challenging to place within the pile cap. While I understand concrete’s poor performance in tension, what is the best approach to balance concrete capacity and anchor reinforcement? Can concrete's contribution to shear strength still be considered in such cases?"
Thanks.
FHWA Safety Factor for Cone Shear Failure in Concrete (ASD):
"Does the FHWA provide a recommended safety factor for concrete cone shear failure in ASD, particularly for micropile and anchor applications? I’ve come across a safety factor of 2.0 being used, but I’d like to confirm if this is in line with FHWA guidelines."
I will also ask for some additional guidance:
I calculated the nominal concrete cone shear strength based on ACI 349 B.11.2, as shown in the FHWA guidelines, and I arrived at the following value:
Dividing by a safety factor of 2.0 gives me an allowable cone shear capacity of 185k. However, the utilization ratio is 1.16 (greater than 1), meaning the demand exceeds this capacity. Some colleagues suggest ignoring the concrete capacity entirely and providing only anchor reinforcement, which would lead to a dense arrangement of reinforcement that would be challenging to place within the pile cap. While I understand concrete’s poor performance in tension, what is the best approach to balance concrete capacity and anchor reinforcement? Can concrete's contribution to shear strength still be considered in such cases?"
Thanks.
