Spring Stiffness of Tendon System & elastic Modulus of Tendon
Spring Stiffness of Tendon System & elastic Modulus of Tendon
(OP)
See attached.
1) Does anyone have any current data or sources that provides an average E of prestressing tendons based on diameter, # of strands, and material grade/relaxation property? Similar to table 2-2. From what I see, strand tendons are not as stiff as bars tendons (if equivalent length and area).
2) How do geotechs convert the assembly of tendon (strand vs bar vs size) and grout/ground stiffness into an equivalent spring for analysis?
Is there a good paper or resource that can explain the conversion from design to model? If springs weren't used, how would 2-D FEM account for the tendon stiffness.
1) Does anyone have any current data or sources that provides an average E of prestressing tendons based on diameter, # of strands, and material grade/relaxation property? Similar to table 2-2. From what I see, strand tendons are not as stiff as bars tendons (if equivalent length and area).
2) How do geotechs convert the assembly of tendon (strand vs bar vs size) and grout/ground stiffness into an equivalent spring for analysis?
Is there a good paper or resource that can explain the conversion from design to model? If springs weren't used, how would 2-D FEM account for the tendon stiffness.





RE: Spring Stiffness of Tendon System & elastic Modulus of Tendon
RE: Spring Stiffness of Tendon System & elastic Modulus of Tendon
For an equivalent spring, you can base it on the elastic elongation of the length of the unbonded zone plus half of the unbonded zone.
RE: Spring Stiffness of Tendon System & elastic Modulus of Tendon
7-wire strands - 28,500 KSI
GR150 Threadbars - 29,700 KSI
RE: Spring Stiffness of Tendon System & elastic Modulus of Tendon
Erdbau - in your commentary you meant "unbonded zone plus half bonded zone" correct? I would assume this would apply for grouted and post grouted tendons....based on the assumption that half the grout in the bonded zone is in tension and half in compression? Would this be different for any other types of anchors such as compression anchors?
Thanks in advance
RE: Spring Stiffness of Tendon System & elastic Modulus of Tendon
RE: Spring Stiffness of Tendon System & elastic Modulus of Tendon
RE: Spring Stiffness of Tendon System & elastic Modulus of Tendon
If you are trying to use FEA for a tiedback wall design, you may be using too powerful a tool for the accuracy of the input soil values. I believe the vast majority of tiedback wall designs use less sophisticated analysis tools.