STATEMENT OF TASKS
Included with this submission is the 3D model of the structural steel included with column, member, and brace locations for each lateral load resisting frame. Single size W sections for beams and columns are used and single size double angles are used for truss members, shown in Appendix A.
For Appendix B, a proposed structural scheme of the building is produced through AutoCAD. Having been provided the architectural cross-section, column orientations, beams and girders, bracing, pinned foundation conditions, member and column lines are produced and labeled for later analysis. A description on how lateral loads are resisted by the structure in both the N-S and E-W directions is reported in the Design Methodology section, where the labels created can be referred.
Seen in Appendix C, determinations of dead, live, snow, roof live, and wind loads on the center are reported using ASCE 7-16. According to the load case combinations of ASCE 7-16, snow and roof live load is chosen by the greatest value followed by explanations of why smaller loads are neglected within the calculations and the meaning behind the maximum load types. Wind loads are shown acting on the parapets and columns on each face of the building and concentrated load diagrams are made suggesting the pressure distributions and distances applied on each lateral load resisting frame (LLRS).
In order to complete the structure, Vulcraft catalogs are referenced in order to select the lightest total weight roof deck and composite floor/deck systems. Identification of the roof deck and evidence that the selected deck has a greater capacity than the service loads it must support is shown in Appendix D. For the floor deck, specifications for the concrete floor deck and thickness are provided. The lightweight concrete deck selected must have a greater capacity than the superimposed service loads.
For Appendix E, the service loads (dead and snow) from Appendix C are used to find the service point loads transferred from the roof joists to the truss. A computer model of the roof truss is prepared using Visual Analysis to perform a static first order analysis. Truss nodes 2-8 in column line 2 are loaded with the calculated point loads and inputted into VA. The VA results will allow for the design of the truss members in Appendix F below.
After the Truss was designed in VA and had the service loads applied to it, the individual members are then able to have their shape determined in Appendix F. Along with determining the shape of the beams; number of connectors, slenderness, spacing, and the deflection of the truss are also needed. The calculations of which are located within Appendix F. Once all the members are accounted for, they will be compiled on table 2 within the appendix. Here the specific member will be displayed along with its shape, properties, and its supplier. Once this information is complete a cost analysis can be performed.
For Appendix G, a cost analysis is conducted based on the governing loads to the truss members. The φPn and the respective equal legged angle are selected and checked by all applicable limit states. Total member weight is determined by the shapes found in the SCM and truss design. Unit Cost and Total Cost is determined through the table provided in Enclosure 1.
In Appendix H, the Vulcraft on-line catalog is referred when selecting an open-web steel joist for the interior roof joists. Knowing the roof loads, we are able to determine the minimum distributed load acting on the joists. Using Tables on pages 46-49, we are able to find the type of joist necessary to support the roof load. From there, we used an equation on page 45 to approximate the gross moment of inertia. Then, using the VMΔ tab (case 1), we are able to determine the deflection of the joist and compare it to the allowable deflection (L/240).
For Appendix I and Appendix J, the service load end reactions from the beams and joists are applied to the girders. From those results, the loads on the girders and beams are transferred to the leaning columns. Calculations are shown for determining the governing load case combinations of each design member. For facilitating a connection between the flange members, coping was conducted and rechecked to ensure that the shear strength of the beams remained commendable for the design. For the floor beam and girder design (Appendix J), work for ensuring room for mechanical ducts can be shown.
For Appendix K, the column design is conducted using the values obtained for the roof joist, roof girders and roof beams. The remaining columns are calculated using values from Appendices E and G. Column base plate designs are completed for column B2 and B3. The bracing for b/c and 2/3 are modeled into Visual analysis and loaded with the wind loading found in Appendix C. The braces are set to tension only and are designed to be WT shapes. All of the members designed in Appendix K are summarized in Table 4a in Appendix M.
In Appendix L, a double angle connections and two unstiffened seat are designed. Limit states for an unstiffened seat and double angle connections are made based on the shear loading from FB1. The shear loading at FG1 is also taken from the FB1 design and used to determine the unstiffened seat design into column B2/B3. Graphics are be shown for each connection within the appendix.
Appendix M, the total estimated structural framing cost is calculated for the entire building. This includes a summary of the trusses, gravity, and lateral systems. Units and unit costs are gathered from the Cost Estimates section of Enclosure 1. A final summary of these results are shown in Tables 4a, 4b, and 5.