A: The coordinates are mostly for reference for downtown Salt Lake City. You can pick any location in the downtown area for rendering purposes.

A: Primarily structural elements such as elevators and stairs should be contained within buildable areas and are not permitted to exist in non-buildable areas for renderings and floor plans.  Primarily architectural/aesthetic elements such as facades may extend into non-buildable areas for architectural renderings.  Teams have the freedom to determine how large the model dimensions scale to architectural floor plans.  The architectural floor dimensions should have the same shape and be proportionally very similar to the dimensions of your balsa wood tower floor plans, just of a realistic scale.  When submitting calculations for your tower’s rentable floor areas (mentioned in Section 2.2.b of the Official Rules), teams should submit based on the dimensions of your balsa wood model.  Architectural floor plan images should be included on the poster and potentially in the presentation.

A: The analysis prediction score (APS) is used to determine which teams receive a bonus based on accuracy of their drift and acceleration predictions.  This bonus is applied to the final annual building income by reducing the final annual seismic cost.  If collapse occurs during either of the ground motions, an APS score of 100% will be awarded, making the team ineligible to receive the bonus based on the APS.

A: The architecture judging will be based on a combination of the physical model and the architectural rendering and plan layouts in your poster.  You should also discuss architecture in your presentation because it’s part of the presentation rubric.  However, the architecture judges will not be viewing the presentations, so the architecture score itself will not be based on the presentations.  There is no separate submission for architecture.

Answer: The team may decide the sequence of the proposal content.

A: To the first question, yes you should submit a complete yet preliminary design.  The model does not have to be fully analyzed, but should be comprehensive enough to show your design intent and the structural layout in a computer-generated image.  As for the second question, your final design does not need to adhere to the preliminary design in the proposal, and there is no penalization for a completely changed design.  You should feel free to modify your structure as necessary throughout the next few months, as long as your final poster and presentation accurately reflect your final design.

A: No, you do not need to calculate any revenue or cost for the proposal.  We recommend briefly mentioning economic considerations for the structure, but calculations like those in the Official Rules are not necessary.

A: The direction of shaking will only be determined on shake day. By the time your model should be completely assembled (tentatively Monday 6pm of competition week), you would not know the direction of shaking. You are not allowed to install the damping devices after that time. Therefore, it would be best to install the damping devices in both directions.

A: Components of damping devices such as pins and connections are not permitted to exceed the outer footprint of the building.  Maximum floor plan dimensions will be checked with templates passed over the structure per Section 5.6.d of the Official Rules.  Violations will be incurred if the template cannot freely pass over any floors; this includes floors with damping devices.

A: The damping system is not required to be designed as removable.  The main reason for this criteria is to make sure that the structure is stable and firmly fixed to the base plate in case the SDC Chairs determine that the damping devices need to be removed prior to shaking (noted in Section 4.2 of the Official Rules). In case SDC Chairs determine that the damping devices must be removed, it would benefit teams to design their devices in a way that extraction of the devices would be relatively straightforward and wouldn’t compromise the structural integrity of the tower.

A: The structure-damper connections do not need to adhere to the rules outlining frame member size as long as they are described in your approved damping proposal.  If the balsa wood members in your connections are not adequately described in the damping proposal and do not conform to the official rules, please email sdc@eeri.org with an image and/or description of your connection to request approval of the balsa wood members.  If the members do not conform to the Official Rules and have not been approved by the SDC chairs, they will either be removed with the damping device or will be allowed to remain with V penalties deducted per the Official Rules.  Should the damper be rejected, the structure-damper connections could potentially remain in place if it is clear they serve no structural purpose.  However, this is at the discretion of the SDC chairs, who may deem that the connections need to be removed.

Answer: Only the weight and loading for the balsa wood structure need to be considered.  The weight of a real, full-scale structure does not need to be computed at any point during the competition.

Answer: No, you cannot place any floor members in the hollow, non-buildable area below floor 8. No members of any kind can occupy the non-buildable area.

Answer: The contact area between a wall member and a frame member can be more than 1 inch in any direction.  There is no restriction on length of faying surface in wall member to frame member connections.

Answer: Wall members can be non-rectangular if the longest vertical distance that can be measured on the wall member is at least 1 inch. Any perforations are allowed in the wall member as long as the total vertical height is at least 1 inch and the total horizontal length is at least 1 inch.  The spacing between the perforations is permitted to be less than 1 inch.

Answer: For the geotechnical portion of this project, we are asking teams to consider the effects the soil would have on the “real” building with “real” foundations, although the shaking will occur on a fixed base during the competition. Architectural components should also correspond to the “real” building. The structural parts of the project should focus on the balsa wood model itself, but these would likely imitate the structural components of a “real” building.

Answer: You may vary the floor area of each floor as long as it is within the maximum floor plan boundaries set by section 5.6d. Your floor area does not have to occupy the maximum floor plan. You may use whatever structural analysis or modeling program you choose, although CSI is providing SAP2000 or ETABS licenses to all teams for free if you want to take advantage of it.

Answer: The specifications for buildable and non-buildable areas of the model must be followed for all elements of the balsa wood model.  If a team chooses to add architectural components to the physical model itself, those must be within the buildable areas.  Any architectural elements in renderings and images of the tower used in the proposal, presentation, or poster do not have to adhere to the buildable and non-buildable areas but should be consistent with the structural design of the tower.

Answer: No access points to the atriums are needed since they are not rentable floor areas.

Answer: No atriums can be counted as rentable floor areas since they are not buildable areas, even for ground floors. The maximum rentable total floor area in the official rules is calculated as:

Max rentable floor area for floors 1-7: 12 x 12 – 6 x 6 = 108 in^2

Max rentable floor area for floors 8-10 and 16-19: 12 x 12 = 144 in^2

Max rentable floor area for floors 11-15: 5.5 x 5.5 = 30.25 in^2

Max rentable total floor area: 108 x 7 + 144 x 7 + 30.25 x 5 = 1915.25 in^2

Therefore, the maximum rentalable total floor area is set to be 1915 in^2.

A: The floors are the specific diaphragms at specific elevations so the buildable areas for each floor (figures 10-12 of the design guide) are showing the buildable areas (extents) of the diaphragms.  This lacks information about the buildable volumes above each floor.  The buildable areas of the diaphragms in figures 10-12 are still consistent with the diaphragm shapes in figure 13 (each line immediately below “f = #” in figure 13 represents the floor diaphragm in figures 10-12).  Figure 13 also shows the buildable volumes above each floor.  In the case of floor 10, the buildable area of the diaphragm (12in x 12in) is not the same as the buildable volume above the floor (5.5in x 5.5in).

Rentable floor areas are derived from the buildable area of the diaphragm.  So the rentable floor areas are also what’s shown in figures 10-12 of the design guide (the floor 10 terrace area could be rented out as a dining area or something).  The bottom of the atrium (floor 1, 6in x 6in center area) is not considered rentable floor area, but the bottom of the terrace (floor 10, full 12in x 12in) is considered rentable floor area.

A: A floor area is considered rentable as long as it is in the buildable area and adheres to the requirements in the Official Rules.  In your architectural design, you can decide what a rentable floor area looks like and what purpose it serves.  Regardless of architectural use, the area will be considered rentable and included in the FABI calculation as long as the structural requirements of Section 5.6.c of the Official Rules are observed.

A: You can have an architectural facade in the non-buildable space in your rendering or images of the structure, but you cannot have any architectural or structural members in the non-buildable space of your physical structure.

A: We recommend that teams focus on precision of construction to ensure that their rentable floor areas are maximized if they choose to build to the maximum areas.  A slight measurement tolerance will be considered when checking rentable floor areas at the competition.  However, this tolerance is up to the discretion of the SDC chairs.  If teams choose to build diaphragms inside of an outer layer of vertical frame members, diagonal frame members, and/or wall members, the outer layer does not need to be subtracted from the rentable floor area and teams can maximize their area as long as the outer layer is at the edges of the buildable area and the marked perimeter beams are attached to the outer layer.  As for members penetrating the diaphragm, it is shown in Figure 14 in the Design Guide that this missed area also does not need to be subtracted from the rentable area.  Finally, we’d like to remind teams that you do not need to build to the maximum rentable floor area and may choose to build smaller than the full buildable area.

A: All frame members and wall members shall be made of balsa wood. The maximum number of floors is 19 and the minimum number of floors is 13. Teams should make sure that their number of floors is within this range. Regardless of the number of floors that teams choose to have, each floor should comply with the requirements of the Maximum Floor Plan Dimensions as shown in Section 5.6.d.

A: Inclined columns are allowed as long as they can fit within the 0.2” by 0.2” by 15” box at any orientation. One way to visualize how those columns can fit within the box is to make the height (the longest side) of the columns parallel with the 15” side of the box.

A: We recommend taking the structure to the competition fully or almost fully assembled, but this is up to the discretion of the teams.  Some teams will send their structure in easily assemblable modules that can be quickly constructed before the start of the competition while most teams will ship the structure in its final state.  Please be aware that all structures must be completely assembled and in their final state by 6pm on Monday of competition week (this timing is tentative but will likely not change significantly).  Therefore, teams who do not ship their structure fully assembled will need to finish constructing it by that time.  Some additional shipping information will be sent in the second mailer.

A: Each floor of your structural model should fit within the buildable areas shown in Section 5.6.d of the Official Rules. It is at each team’s discretion to decide the exact dimensions for each floor, as long as the dimensions fit within these limits.  Therefore, for floors 1-7, the exact dimensions can be adjusted as long as they do not cross into the hatched 6 in x 6 in region or extend outside the 12 in x 12 in square.

A: The term “bulky columns” in the problem statement generally refers to bundle columns, where vertical frame members are spaced very close together to increase overall column dimensions.  The bolded sentence in Section 5.2.a of the Official Rules imposes a minimum spacing of vertical frame members, essentially disallowing the use of bundle columns consisting of tightly spaced frame members.  All kinds of columns are allowed as long as they satisfy the requirements stated in the Official Rules.

A: There is a 6 in. x 6. in non-buildable area for floors 1-7. This minimum atrium space is described in Section 5.6.d of the Official Rules.

A: The 1” x 2.25” access point refers to a clear opening of this dimension on the vertical plane for each floor instead of an opening on the floor plan. It is intended to represent the clearance that occupants need to be able to physically walk around the floor and access other spaces.  An opening through the floor plan is not required, but there are span requirements between beams specified in Section 5.6.c.

A: Yes, this would be typical in members used as columns as long as the individual members satisfy requirements outlined in the Official Rules

A: Regarding the first question, all rentable floor area must be accessible from the rest of the floor in question.  In Figure 14 of the Design Guide, the bottom right section of floor meets the requirements for maximum spans but would not be counted as rentable floor area because the adjacent sections of floor have spans that are greater than the maximum allowed, making the bottom right section inaccessible.  Regarding the second question, the beam layout is at the discretion of the teams and may be + shaped or x shaped, as long as the span requirements and other requirements of Section 5.6 of the Official Rules are satisfied.

A: Only 1 opening is required to access the rentable floor area between the exterior and interior sections of the 10th story.  The only point where 2 openings are required is the exterior of the first floor (Section 5.6.c of the Official Rules).

A: We recommend that teams using SI units convert imperial units to SI units, add the tolerance (if they need to take advantage of the tolerance), and then round down to the nearest integer of mm to get the maximum allowed dimension.  For example, for the base plate dimension mentioned in the question, Section 5.7.a of the Official Rules describes a 0.25 inch tolerance.  This would result in maximum base plate dimensions of 18.25 in. x 18.25 in., which is 463.55 mm x 463.55 mm.  Rounding down to the nearest integer of mm would give 463 mm x 463 mm.  This will still be within the allowable dimension and will be easier for teams using SI units to cut the base plate.  Please note that the 0.25 in. tolerance is only for the base plate and other dimensions have different tolerances.  This information can be found in the Structural Model section of the Official Rules.  For example, Section 5.2.a specifies that frame member dimensions have a tolerance of 0.01 inches.  The above recommendation is intended for the convenience of teams that use SI units, but the competition is still judged using imperial units.

A: If the inclined column or bracing interferes with the opening used for the access point then the rentable area after that bracing will not be included if it has no other access points (see Section 5.6.c of the Official Rules).  Inclined columns and bracing are permitted within the middle of the floor area as long as they don’t interfere with the access points.  Section 5.6.c also states that the area of individual inclined and vertical frame members and wall members penetrating the floor do not need to be subtracted from the rentable floor area.  Please note that for floor 10, inclined columns and bracing are not permitted above the outer section of the rentable floor area (see Figure 13 of the Design Guide and Clarification Question Q5.10).

A: This access point would be ruled null due to the rod-holding members.  The minimum 1 in. x 2.25 in. access point discussed in Section 5.6.c of the Official Rules must be clear of any balsa wood members.

A: Connections of floor beams may be in direct contact with the gusset plate rather than the interior column. However, please note that  a single gusset member may not be in contact with another gusset member and that gussets must be attached to at least two frame members already in contact (in your scenario, the two column members are already in contact).

A: The top of each floor must be flat and level across the whole floor area according to the first bullet point of Section 5.6.b of the Official Rules.  Teams are, however, permitted to place additional members below the floor plane as long as the other requirements of the Official Rules are met.  For example, Section 5.6.c requires a minimum height clearance of 2.25 in. for all rentable floor areas and Section 5.4.b limits the size of the faying surface between frame member to frame member connections.

A: Every single floor of the building requires an access point as defined in the Official Rules Section 5.6.c within the interior of the floor. Additionally, occupants on the lobby floor, or f =1, should be able to access the exterior of the building through at least two access points or doorways.5

A: Yes, you are allowed to place horizontal members between vertical members at any elevation, as long as you ensure that the minimum vertical member spacing requirement and all frame member requirements are met.  Also, remember to check that the horizontal members do not cut off access to any rentable floor area (all rentable areas should be accessible via access points defined in Section 5.6.c of the Official Rules).

Image 1: here

A: Yes, this conforms to the official rules and is allowed.

A: Per Section 5.4.c of the Official Rules, gusset plates shall be in contact with and glued to at least two frame members in contact.  Since the base plate is not considered a frame member, gusset plates would technically not be allowed.  However, you may be able to make a wall member work as long as the triangle’s vertical and horizontal dimensions are at least 1 in. per Section 5.3.a of the Official Rules.  To attach the model to the base plate, we’d recommend drilling holes or notching the base plate so that frame and wall members can be slotted into the holes and glued for a secure attachment (Section 5.7.c of the Official Rules).

A: For the first question, the frame member and wall member would count as two separate elements and this would be permitted per Sections 5.2-5.4 of the Official Rules.  For the second question, because these are all wall members layered on top of each other, the final wall would violate Section 5.4.d of the Official Rules, where all wall members in their final glued state must have a thickness less than or equal to 0.1 in. The thickness of your wall in the final glued state based on your description exceeds this limit.

A: Gusset plates are not allowed to be in the non-buildable floor area.  All floors of the model must fit within the specified floor plan dimensions per Section 5.6.d of the Official Rules.

Answer: The ground motions will be available on the competition website after the proposal submission. The structure should be designed in accordance with the official rules. A complete analysis and a finalized design of the structure are not necessary for the proposal, so teams shouldn’t need ground motions prior to the proposal submission.  Ground motions from competitions in prior years can be made available upon request to sdc@eeri.org before the new ground motions are released.

A: The ground motions posted in the zip file on the competition website are already modified and scaled. These acceleration time histories will be input directly to the shake table.

A: The Sa values are in terms of “g” – acceleration due to gravity. Multiply values by “g” (= 9.81 m/s^2) to obtain Sa in m/s^2.

A: Temporary 3D printed supports may be used as long as they are placed and removed within the dead load installation time limit described in Section 6.4a. After the dead load installation time has expired, dead loads must be secured to the structure only through the methods described in Section 6.4a.

A: The Butterworth filter should be applied to the signal itself in the time domain, not the amplitude spectrum in the frequency domain. The wording is incorrect in Section 6.7 and will be amended. It is recommended, however, to look at the response of the signal in the frequency domain to understand why a Butterworth filter with a corner frequency of 0.8 Hz is recommended.

A: The product information for the accelerometers that will likely be used at the competition can be found at the following link: https://www.te.com/usa-en/product-4030-006-120.html