Module on the Assessment of the Structural Condition

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Module on the Assessment of the Structural
Condition

• Bucharest October 5-7, 2010

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Condition Assessment Based on Strain Measurements
(Long-term Behavior)

• Direct Evaluation of Internal Forces from
  Measurements Data
•  
• Required number of strain sensors
• Column Cross-section 3
• Beam Cross-section 2
• Columns 2 Cross-sections 2x3 6
• Beams 3 Cross-sections 3x2 6
• Example 5 storey building
• 25 columns and 40 beams per storey
•  
• Required number of strain sensors
• N 5 ( 25x640x6 ) 5x390 1950

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Condition Assessment Based on Strain Measurements
(Long-term Behavior)

• Indirect Evaluation of Internal Forces by
  Computer Aided Analysis
• Main Long-term Effects
• Shrinkage and Creep of Concrete
• Differential Foundation Settlements
• From measurement data, the variations of the
  reaction forces on the foundation are evaluated
• The internal forces of the totality of the
  elements are calculated by a non linear analysis
  computer program
• Required number of strain sensors
• Base column cross-section over the foundation
  3
• Concrete specimen for shrinkage measurement 2
• Concrete specimen for creep measurement 2
• For the above example N 25x322 79

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Condition Assessment Based on Strain Measurements
(Long-term Behavior)
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2. Long Term Behavior

• 2.2 Local Condition
• Table 3 Actual and Ultimate Internal Forces
  Safety Factors
• 2.3 Global Condition
• Table 4 Differential Settlemennts

Column Internal Forces Actual Internal Forces Actual Internal Forces Actual Internal Forces - Ultimate Internal Forces - Ultimate Internal Forces - Ultimate Safety
c60/40 N Mx My NR MxR MyR Factor
52 -778.67 208.69 -13.60 -2658.15 712.41 -46.41 3.41
53 -804.09 20.41 -131.89 -6761.24 171.58 -1108.98 8.41
54 -1280.71 -261.52 34.81 -3439.06 -702.26 93.47 2.69
55 -1078.04 -10.31 152.93 -2107.08 -20.16 298.91 1.95
56 -778.67 208.69 -13.60 -2658.15 712.41 -46.41 3.41
57 -1039.17 20.09 141.92 -1161.03 22.44 158.57 1.12
Column Ng NQ,n Nn ?Nn ?d,n ?dG,n ?dQ,n
52 -584.00 -199.41 -778.67 -9.42 -0.0041 -0.0031 -0.0010
53 -619.15 -176.40 -804.09 11.45 -0.0032 -0.0024 -0.0007
54 -1011.76 -245.81 -1280.71 51.98 -0.0087 -0.0066 -0.0019
55 -840.87 -211.76 -1078.04 29.56 -0.0071 -0.0054 -0.0015
56 -568.43 -197.16 -778.67 -29.93 -0.0039 -0.0030 -0.0009
57 -748.20 -274.38 -1039.17 -53.64 -0.0036 -0.0027 -0.0008
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2. Long Term Behavior2.3 Global Condition

• Non-linear structural analysis by SAP2000
• ?G(DL) ?Q(LL) ?G(?dG)?Q?1(?dQ)?G(S)
• From the analysis results the capacity of the
  structural members
• Table 5 Internal Forces

Frame Station OutputCase CaseType P V2 V3 T M2 M3 PMMRatio
Text m Text Text KN KN KN KN-m KN-m KN-m Unitless
52 0 COMB1 Combination -189.7 -3.15 -5.17 0 -5.4 -2.9 0.0565
52 3.5 COMB1 Combination -168.7 -3.15 -5.17 0 12.71 8.11 0.0692
53 0 COMB1 Combination -189.7 -3.15 5.17 0 5.4 -2.9 0.0565
53 3.5 COMB1 Combination -168.7 -3.15 5.17 0 -12.71 8.11 0.0692
54 0 COMB1 Combination -298.2 0.26 -7.02 0 -6.27 0.11 0.0883
54 3.5 COMB1 Combination -277.2 0.26 -7.02 0 18.32 -0.8 0.1017
55 0 COMB1 Combination -298.2 0.26 7.02 0 6.27 0.11 0.0883
55 3.5 COMB1 Combination -277.2 0.26 7.02 0 -18.32 -0.8 0.1017
56 0 COMB1 Combination -184.9 2.89 4.8 0 5.25 2.91 0.0551
56 3.5 COMB1 Combination -163.9 2.89 4.8 0 -11.55 -7.2 0.064
57 0 COMB1 Combination -184.9 2.89 -4.8 0 -5.25 2.91 0.0551
57 3.5 COMB1 Combination -163.9 2.89 -4.8 0 11.55 -7.2 0.064
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3. Seismic Behaviour
dx1,dy1,dx2,dy2 Horizontal displacements at
A1,A2 as functions of time d d(t) ,
resulting after double
integration of the
acceleration a d(t)
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3. Seismic Behaviour3.1 Seismic Displacements

• Velocities
• Displacements
•  
• Table 6 Accelerations and displacements at the
  positions of the two
• accelerometers in the storey m.

Storey 1
n tn (x10-3s) a(11x) d(11x) a(11y) d(11y) a(12x) d(12x) a(12y) d(12y)
1 0.0 -4.54274552 -7.098E-06 -5.615 -8.774E-06 4.937 7.715E-06 -2.104 -3.288E-06
2 2.5 2.91755656 -2.383E-05 -1.558 -3.753E-05 -1.464 2.857E-05 6.157 -3.533E-06
3 5.0 4.37274565 -3.172E-05 -0.045 -8.000E-05 -4.283 4.588E-05 4.441 1.911E-05
4 7.5 2.8562432 -1.691E-05 -6.080 -1.346E-04 0.962 4.901E-05 4.739 7.266E-05
5 10.0 -0.89236307 1.225E-05 5.440 -1.997E-04 -4.446 4.152E-05 5.735 1.569E-04
6 12.5 6.72968637 5.361E-05 4.211 -2.507E-04 -3.430 1.627E-05 -2.050 2.633E-04
7 15.0 -0.7127606 1.135E-04 1.611 -2.776E-04 -4.407 -3.353E-05 -3.211 3.672E-04
8 17.5 -6.23239902 1.719E-04 1.411 -2.906E-04 -0.612 -1.034E-04 -4.097 4.515E-04
9 20.0 0.96207225 2.113E-04 -4.717 -3.041E-04 -2.564 -1.861E-04 0.973 5.195E-04
10 22.5 -0.55062712 2.430E-04 -6.500 -3.403E-04 -0.970 -2.793E-04 0.672 5.851E-04
11 25.0 -4.61449301 2.673E-04 -0.489 -4.050E-04 1.552 -3.771E-04 2.982 6.591E-04
12 27.5 3.75002087 2.822E-04 -6.769 -4.919E-04 3.733 -4.657E-04 -4.635 7.361E-04
13 30.0 1.57766114 3.041E-04 -5.797 -6.097E-04 -0.152 -5.405E-04 4.147 8.099E-04
14 32.5 -2.96115475 3.321E-04 -1.899 -7.593E-04 -0.552 -6.107E-04 -1.511 8.869E-04
15 35.0 3.00919965 3.581E-04 0.661 -9.228E-04 3.151 -6.780E-04 2.128 9.691E-04
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3. Seismic Behaviour3.3. Local Condition

• Total Plastic Rotation
• Resultant Bending Moments
• Damage Index
• Table 10. Damage Index D

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3. Seismic Behaviour3.4. Global Condition
Total Failure Condition Format
ion of Plastic Hinge Storey Mechanism
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3. Seismic Behaviour3.4. Global Condition

• 0.20 ? Plastic Hinge
• IF
• nm The number of columns in the storey
• 2nm The required number of hinges for
  instability
• nhm The number of hinges develeved in storey ,
  the index
• of instability of the storey is
• Index of the Global Instability of the Building
• Table 11. Index of Global Instability