1. CFHT Pier Building Evaluation
27/06/2018
CFHT Pier Building Evaluation
Work summary
Analysis concerns and discussion
Future work
27/06/2018
CFHT Pier Building Evaluation by Mathieu Angers

2. CFHT Pier Building Evaluation by Mathieu Angers
27/06/2018
Work Summary
Evaluation of the capacity is done according to International Building Code (IBC) and the American Concrete Institute code (ACI318).
Structure modeled in ANSYS and SAP2000 to obtain the stresses and forces.
ANSYS Mechanical can perform parametric studies.
SAP2000 has the building codes implemented and allows to do design.
Results of ANSYS and SAP2000 are compared.
The capacity is evaluated with material mechanic principles to compare to the software results. ACI 371 concrete pedestal water towers code was used as well as ACI 318.
Bending capacity
In-plane and radial shear capacity
Axial capacity
27/06/2018
CFHT Pier Building Evaluation by Mathieu Angers

3. CFHT Pier Building Evaluation by Mathieu Angers
27/06/2018
Work Summary
The pier building is now modeled in both softwares.
Without the ring girder and telescope frame.
Openings are modeled.
Soil-Foundation interaction considered.
Analysis
Elastic analysis
Modal analysis
Response spectrum analysis
Load combinations according to IBC 2008.
1.4 dead load
1.2 dead load live load
1.2 dead load earthquake load live load
Peak ground acceleration used: 1.17g. Value given in the IBC
27/06/2018
CFHT Pier Building Evaluation by Mathieu Angers

4. CFHT Pier Building Evaluation by Mathieu Angers
27/06/2018
Work Summary
Results from the softwares
Stresses
Forces
Base reactions
Natural periods
Mode shapes
Envelope of the different load combinations
SAP2000 has a function that permits the evaluation of the required amount of steel necessary to resist the different load combinations.
These results will be compared to the pier building reinforcement to evaluate the structure.
Foundations
Analysis is being done by Dr. WuDi and Andy Liu.
Bearing capacity of the soil.
Structural capacity of the footings.
Settlements of the soils.
27/06/2018
CFHT Pier Building Evaluation by Mathieu Angers

5. CFHT Pier Building Evaluation by Mathieu Angers
27/06/2018
Work Summary
TABLE: Modal Periods And Frequencies
OutputCase
StepType
StepNum
Period
Frequency
CircFreq
Eigenvalue
Text
Unitless
Sec
Cyc/sec
rad/sec
rad2/sec2
MODAL
Mode 1
5.4207
34.059
1160 2
6.1558
38.678
1496 3
6.3542
39.925
1594 4
8.9101
55.984
3134.2 5
9.7823
61.464
3777.8 6
11.377
71.486
5110.2 7
11.407
71.673
5137 8
17.48
109.83
12063 9
18.258
114.72
13160 10
18.789
118.05
13936 11
18.868
118.55
14054 12
20.857
131.05
17174
27/06/2018
CFHT Pier Building Evaluation by Mathieu Angers

6. CFHT Pier Building Evaluation by Mathieu Angers
27/06/2018
Discussion
Telescope configuration
Ring girder placed on the top floor without any modification to the pier building.
+ No work to be done on the pier building.
+ Integrity of the pier building is not modified (No rebars cut at the joints and stiffness of the structure is conserved).
- No reduction in the weight of the structure (high stresses).
- Does not provide additional height for the telescope.
Top storey completely removed and ring girder placed on the second floor.
+ Provides additional height for the telescope.
+ Reduces the weight of the structure.
- Problems at the section where the wall will be cut. Lap splices being cut: loss of capacity and stiffness.
Top slab is removed and replaced by a light weight steel slab. Ring girder placed on the top of the wall.
+ Reduction of the weight
27/06/2018
CFHT Pier Building Evaluation by Mathieu Angers

7. CFHT Pier Building Evaluation by Mathieu Angers
27/06/2018
Discussion
Rebar information
The most recent plans are the SNC drawings and represent the actual structure. (Foundation on site is of the SNC plans)
Rebar lists referred by the SNC placing drawings were not found.
Solution: Use the bar sizes and spacing from the IEC drawings.
Problem: No information on rebar sizes and spacing for the ring wall foundation.
Links between the pier and the enclosure.
Confirm that the wind loads are not transmitted to the pier.
27/06/2018
CFHT Pier Building Evaluation by Mathieu Angers

8. CFHT Pier Building Evaluation by Mathieu Angers
27/06/2018
Future work
Finish the evaluation of the soils and foundation (Dr. WuDi and Andy Liu)
Improve the seismic analysis.
Ameliorate the soil-structure interaction model.
Model in SAP2000 and ANSYS the telescope structure.
Ring girder and its connections to the pier.
Telescope support frame.
Telescope mass and mass moment of inertia.
Comparison of the results of the analysis with the actual structure.
Final assessment of the pier building.
27/06/2018
CFHT Pier Building Evaluation by Mathieu Angers

9. CFHT Pier Building Evaluation by Mathieu Angers
27/06/2018
QUESTIONS?
27/06/2018
CFHT Pier Building Evaluation by Mathieu Angers