TSC Torsional Strength

Notation

A_o = area of shear reinforcement
A_ot = Area of transverse torsion reinforcement
A_ov = Area of transverse shear reinforcement
A_s-mint = minimum area of longitudinal reinforcement to resist torsion
b_w = web width or diameter of circular section
d = distance from extreme compression fiber to centroid of longitudinal tension reinforcement
f_ck = specified compressive strength of concrete
f_cd = design compressive strength of concrete
f_yk = specified yield strength for nonprestressed reinforcement
f_yd = design yield strength for nonprestressed reinforcement
f_ywk = specified yield strength of transverse reinforcement
f_ywd = design yield strength of transverse reinforcement
T_cri = critical torsional moment,
T_d = design torsional moment,

Torsional design is made with the reinforcement requirement determined by comparing the factored torsional moment T_d value with the critical torsion limit T_cr value.

• Torsional effects can be neglected if the design torsional moment at section T_d is critical torsion limit T_cr

• If design shear force and torsional moment are satisfied the TS 500 Eq. 8.10 equation, there is no need to compute torsional stirrups.

Critical Torsion Limit

Critical torsion T_cri is calculated in accordance with TS 500 Eq. 8.12.

S is calculated in accordance with TS 500 Table 8.2.

for rectengular section

for T-beam section. x and y long and short rectengular dimensions of T-beam section.

for circular section.

Minimum shear reinforcement should be satisfied given below;

If design shear force and torsional moment are satisfied the TS 500 Eq. 8.10 equation, there is no need to compute torsional stirrups.

where T_cr is computed as follows:

The required minimum closed stirrup area per unit spacing, A_o/s, is calculated as:

In equiation.

If T_d > T_cr the required longitudinal rebar area, (required minimum longitudinal rebar area), A_s-mint, is calculated as:

If T_d > T_cr the required closed stirrup area per unit spacing, is calculated in accordance with TS500 Eq. 8.13 as: