Comein

Calculation of the T-section Wall Segment for Eccentric Compression (Eccentricity towards the Flange)

Objective: Check of the calculation of eccentrically compressed columns.

Task: Verify the correctness of the stability analysis under eccentric compression.

References: Reference manual on design of masonry and reinforced masonry structures (supplement to SNiP II-22-81), 1989, p. 19-20.

Initial data file:

Example 2.SAV;
ComeIn 2.doc — report

Initial data:

N = 850 kN Longitudinal force;
е0 = 0,16 m Force eccentricity;
Н = 5 m Storey height;
Stone/brick Molded clay brick, grade 100;
Mortar Regular cement with mineral plasticizers, grade 50;
R = 1,5 MPa Design resistance of masonry;
Нf  = 0,22 m Thickness of the precast reinforced concrete floor slab, embedded into wall masonry on the supports.

COMEIN initial data:

Importance factor  γn = 1
Age of masonry - up to a year
Working life is 25 years
Stone/brick - Molded clay brick
Stone/brick grade - 100
Mortar - regular cement with mineral plasticizers
Mortar grade - 50

Structure:

Eccentricity of longitudinal force - 16 cm along the Y axis
Column height 4,78 m
Longitudinal force 850 kN
Factor for sustained load 1

 

Effective height in the XoY plane

 

Effective height in the XoZ plane

Bracing scheme
Precast floor slabs
Distance between transverse rigid structures 5 m
Effective height factor 0,9

Bracing scheme
Precast floor slabs
Distance between transverse rigid structures 5 m
Effective height factor 0,9

Comparison of solutions:

Check

Stability in the eccentricity plane under eccentric compression

Theory

850/1080 = 0,787

COMEIN

0,774

Deviation, %

1,652

Comments:

  1. The column height in ComeIn is taken as the difference between the storey height and the floor slab thickness Н - Нf  = 5 – 0,22 = 4,78 m.
  2. Distance between transverse rigid structures has to be specified in ComeIn. Since it is not determined in the problem, the value of 5 m is used.
  3. Age of masonry and working life have to be specified in ComeIn. Since they are not determined in the problem, the following data are used: "up to a year" and 25 years respectively.
  4. Deviation of the stability factor value in ComeIn from the result of the solution of the problem is caused by the fact that the requirements of Sec. 4.7 of SNiP II-22-81 (Sec. 7.7 of SP 15.13330.2012) for determining slenderness for the compressed part of the section for an alternating bending moment diagram are not taken into account when solving the problem.