Part 2 – Problem 07: Should the addition be treated separately from the existing structure? If so, please confirm.
No, please consider the addition and existing structure as a single building in part 2 of the structural deliverable. In reality, the additional structure will be put on the existing building to perform together in an integral way
Part 2 – Problem 08: This section notes “Use drawings to describe how connections will be designed between the addition and the existing structure and how connections will be implemented within the addition itself.” Does this mean we are to design steel connections or balsa wood for the drawing package
We would like you to design balsa wood connections for this part. The structural drawings in part 2, question 3 should all correspond to a balsa wood model.
Part 2 – Problem 09: The Deliverable mentions “Your company has been tasked with designing a structural system that will accommodate this tapered geometry without altering the existing hospital structure.” If we had determined poor performance in part 1 where the structure would be at risk of failing, are we only to look for acceptable performance of the addition under the assumption that the existing structure will be edited and fixed in deliverable 4, or are we to make a structure that is expected to stand in this deliverable?
Yes, this is correct. In this deliverable, we are asking for a preliminary design for the additional structure that you believe will perform well with the existing building once the existing building is retrofitted.
Part 1 – Problem 08: Since the buildings diaphragms should be flexible and have zero stiffness, should we ignore torsional properties of the building or how should we account for this instead?
Torsion should still be considered regardless of how diaphragms are defined. Torsion will likely appear in your mode shapes and it would be advantageous to attempt to minimize torsion in your design.
Part 1 – Problem 09: The deliverable states that Allowable Stress Design load combinations should be used when determining member forces, referring to ASCE 7 for the appropriate load combinations. Should we choose the combinations according to paragraph 2.4.5/pg.8-9 from ASCE? Could you give us more insight about these combinations, taking into account the fact that we are not familiar with ASCE and we want to avoid introducing wrong data in our SAP2000 model?
Yes, you are correct that section 2.4.5 of ASCE 7-16 refers to the appropriate load combinations. Rather than calculating Ev and Eh using section 12.4.2, it is permitted to simply input the time history as Eh and neglect Ev. Additionally, you may disregard overstrength.