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V. SNiP SP16 2017 - Column in compression

Design a column per the SP 16.13330.2017 code.

Details

A 6.78m tall, simply supported column has a Russian K2-30 section. The column is subject to a 1,500 kN axial load. The steel used has a modulus of elasticity of 206,000 MPa and a Ry = 239 MPa. γc1 = 1, γc2 = 1

Validation

Check for Axial Force

Need to satisfy the following equation:

N A n R y γ c 1 (Eq. 5)

Thus, the ratio is 1 , 500 122.7 × 10 1 × 239 × 1 = 0.51 < 1

Check the slenderness per Cl. 10.4.1. Limit the slenderness to 120.

λ x = k x l r x = 1.0 × 6.78 0.131 = 51.91 < 120
λ y = k y l r y = 1.0 × 6.78 0.0754 = 89.92 < 120

Thus, the ratio is 89.92 / 120 = 0.75

Check Cl. 7.1.3

λ ¯ x = λ x R y E = 51.91 239 206 , 000 = 1.768
λ ¯ y = λ y R y E = 89.92 239 206 , 000 = 3.063

Therefore, λ ¯ = 3.063

Need to satisfy the following equation:

N ϕ A R y γ c 1 (Eq. 7)(
where
ϕ
=
0.5 δ δ 2 39.48 × λ ¯ 2 λ ¯ 2 , per Eq. 8
δ
=
9.87 ( 1 α + β λ ¯ ) + λ ¯ 2 , per Eq. 9

From Table 7, note 2, α = 0.04 and β = 0.14.

δ = 9.87 [ 1 0.04 + 0.14 ( 3.063 ) ] + ( 3.063 ) 2 = 23.09
ϕ = 0.5 23.09 ( 23.09 ) 2 39.48 × ( 3.063 ) 2 ( 3.063 ) 2 = 0.551 < 7.6 λ ¯ 2 = 7.6 ( 3.063 ) 2 = 0.810

Thus, the ratio is 1 , 500 0.551 × 122.7 × 10 1 × 239 × 1 = 0.93 < 1

Check Cl. 7.3.2

Design height of the cross-section wall, hef = 238 mm (Cl. 7.3.1)

λ ¯ w = h e f t w R y E = 238 10 239 206 , 000 = 0.811

Since λ ¯ = 3.063 > 2 , λ ¯ u w = 1.20 + 0.35 λ ¯ = 2.27 < 2.3 (per F.(24), Table 9)

λ ¯ w < λ ¯ u w , OK

Check Cl. 7.3.8

Design width of the cross-section wall, bef = b/2 - 2×tw = 130 mm

λ ¯ f = b e f t f R y E = 130 15.5 239 206 , 000 = 0.286

Since λ ¯ = 3.063 > 2 , λ ¯ u f = 0.36 + 0.10 λ ¯ = 0.67 (per F.(37), Table 10)

λ ¯ f < λ ¯ u f , OK

Results

Result Type Reference STAAD.Pro Difference Comments
Ratio per Cl. 7.1.3 0.93 0.93 none  
Ratio per Cl. 7.1.1 0.51 0.51 none  
Ratio per Cl. 10.4.1C 0.75 0.75 none  
λ¯w 0.811 0.8106 negligible  
λ¯uw 2.27 2.27 none  
λ¯f 0.286 0.286 none  
λ¯uf 0.67 0.66 negligible  

STAAD.Pro Input

The file C:\Users\Public\Public Documents\STAAD.Pro CONNECT Edition\Samples\ Verification Models\09 Steel Design\Russia\SNiP SP16 2017 - Column in compression.STD is typically installed with the program.

STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 08/31/2020
END JOB INFORMATION
INPUT WIDTH 79
UNIT METER KN
JOINT COORDINATES
1 0 0 0; 2 0 6.78 0;
MEMBER INCIDENCES
1 1 2;
DEFINE MATERIAL START
ISOTROPIC STEEL
E 2.05e+08
POISSON 0.3
DENSITY 76.8195
ALPHA 1.2e-05
DAMP 0.03
TYPE STEEL
STRENGTH FY 253200 FU 407800 RY 1.5 RT 1.2
END DEFINE MATERIAL
****************************************
MEMBER PROPERTY RUSSIAN
1 TABLE ST K2-30
****************************************
CONSTANTS
MATERIAL STEEL ALL
SUPPORTS
1 PINNED
2 FIXED BUT FY MX MZ
****************************************
LOAD 1 LOADTYPE None  TITLE LOAD CASE 1
JOINT LOAD
2 FY -1500
********************************
PERFORM ANALYSIS
*********************************
PARAMETER 1
CODE RUSSIAN
TRACK 2 ALL
TB 1 ALL
CMN 2 ALL
SGR 20 ALL
CHECK CODE ALL
FINISH

STAAD.Pro Output

                       STAAD.PRO CODE CHECKING - (SP 16.13330.2017)   V1.0
                       ********************************************
   ALL UNITS ARE - KN METRE
   ========================================================================
   MEMBER     CROSS          RESULT/   CRITICAL COND/    RATIO/    LOADING/
              SECTION NO.      N             Mx            My      LOCATION
   ========================================================================
      1  I      K2-30         PASS      SP cl.7.1.3      0.93         1
                          1.500E+03 C    0.000E+00    0.000E+00   0.000E+00
      1  I      K2-30         PASS      SP cl.7.1.1      0.51         1
                          1.500E+03 C    0.000E+00    0.000E+00   0.000E+00
      1  I      K2-30         PASS      SP cl.10.4.1C    0.75         1
                          1.500E+03 C    0.000E+00    0.000E+00   0.000E+00
   MATERIAL DATA
      Steel                         = C255B      SP16.13330
      Modulus of elasticity         = 206.E+06 kPa
      Design Strength (Ry)          = 239.E+03 kPa
   SECTION PROPERTIES (units - m, m^2, m^3, m^4)
      Member Length                 = 6.78E+00
      Gross Area                    = 1.23E-02
      Net Area                      = 1.23E-02
                                         x-axis      y-axis
      Moment of inertia (I)         :   209.E-06    698.E-07
      Section modulus (W)           :   140.E-05    465.E-06
      First moment of area (S)      :   771.E-06    349.E-06
      Radius of gyration (i)        :   131.E-03    754.E-04
      Effective Length              :   6.78E+00    6.78E+00
      Slenderness                   :   519.E-01    899.E-01
   DESIGN DATA (units -kN,m) SP16.13330.2017
      Axial force                   :   150.0E+01
                                         x-axis      y-axis
      Moments                       :   0.000E+00    0.000E+00
      Shear force                   :   0.000E+00    0.000E+00
      Bi-moment                     :   0.000E+00 Value of Bi-moment not being entered!!!
   CRITICAL CONDITIONS FOR EACH CLAUSE CHECK
      F.(7)  N/(FI*A*Ry*GammaC)= 150.0E+01/( 5.51E-01* 1.227E-02* 239.0E+03* 1.00E+00)= 9.28E-01=&lt;1
      7.3 cl. LAMBDA_w&amp;lt;=LAMBDA_uw= 8.11E-01&amp;lt;= 2.27E+00 OK
              LAMBDA_f&amp;lt;=LAMBDA_uf= 2.86E-01&amp;lt;= 6.66E-01 OK
      F.(5)  N/(An*Ry*GammaC)= 150.0E+01/( 1.23E-02* 239.0E+03* 1.00E+00)= 5.11E-01=&lt;1
      ULTIM. SLENDERNESS >= Lambda_y 120.0E+00 >= 898.9E-01