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
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
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 + 1.6 live load 1.2 dead load + 1.0 earthquake load + 0.5 live load Peak ground acceleration used: 1.17g. Value given in the IBC 27/06/2018 CFHT Pier Building Evaluation by Mathieu Angers
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
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 0.184478 5.4207 34.059 1160 2 0.162448 6.1558 38.678 1496 3 0.157376 6.3542 39.925 1594 4 0.112232 8.9101 55.984 3134.2 5 0.102225 9.7823 61.464 3777.8 6 0.087894 11.377 71.486 5110.2 7 0.087665 11.407 71.673 5137 8 0.057207 17.48 109.83 12063 9 0.054771 18.258 114.72 13160 10 0.053224 18.789 118.05 13936 11 0.053001 18.868 118.55 14054 12 0.047945 20.857 131.05 17174 27/06/2018 CFHT Pier Building Evaluation by Mathieu Angers
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
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
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
CFHT Pier Building Evaluation by Mathieu Angers 27/06/2018 QUESTIONS? 27/06/2018 CFHT Pier Building Evaluation by Mathieu Angers