Arlington Gateway Hotel 801 North Glebe Road Arlington, Virginia Michael Gray Penn State University AE Senior Thesis Presentation 2005

Arlington, Virginia Michael Gray Structural Option Arlington Gateway Hotel Introduction Background Current Structure Alternate Systems Structural Redesign Cost and Scheduling Recommendation Background Current Structural System Alternate Structural Systems Structural Redesign Cost and Scheduling Final Recommendation Outline of Presentation

Arlington, Virginia Michael Gray Structural Option Arlington Gateway Hotel Introduction Background Current Structure Alternate Systems Structural Redesign Cost and Scheduling Recommendation Site – Arlington Gateway 22 Story Residential tower 13 Story Office Building 15 Story Arlington Gateway Hotel

Arlington, Virginia Michael Gray Structural Option Arlington Gateway Hotel Introduction Background Current Structure Alternate Systems Structural Redesign Cost and Scheduling Recommendation General Information - 250,000 Square Feet Units - Estimated cost $40 million - Westin Hotel & Resort - Located within 5 min. of Reagan National Airport Amenities - Starbucks Cafe - Restaurant and Lounge - Ballroom and Meeting Facilities - Indoor Swimming Pool - Fitness Center and Spa

Arlington, Virginia Michael Gray Structural Option Arlington Gateway Hotel Introduction Background Current Structure Alternate Systems Structural Redesign Cost and Scheduling Recommendation Structural System psi Concrete In Slabs - Mix of 4000 to 6000 psi Concrete In Columns - Reinforced Cast-In-Place Concrete - 8” Two-Way Flat Slab Construction (Typical) Design Codes - BOCA 96 - ASCE 7-95 Lateral System - Moment Frames

Arlington, Virginia Michael Gray Structural Option Arlington Gateway Hotel Introduction Background Current Structure Alternate Systems Structural Redesign Cost and Scheduling Recommendation Alternate Systems for Mid-Rise Residential Structures - Hybrid Systems – Steel and Precast - Prestressed Precast Concrete - Metal Deck and Composite Steel Beams Staggered Truss SystemThe Girder-Slab System

Arlington, Virginia Michael Gray Structural Option Arlington Gateway Hotel Introduction Background Current Structure Alternate Systems Structural Redesign Cost and Scheduling Recommendation Alternate System Selection - Any site constraints? - How will it work with current floor plan? - Will it maintain the current 8’-9” story height? Staggered TrussGirder-SlabFlat-Slab Fire Resistance345 Light Weight552 Speed of Construction543 Adaptable to current layout

Arlington, Virginia Michael Gray Structural Option Arlington Gateway Hotel Introduction Background Current Structure Alternate Systems Structural Redesign Cost and Scheduling Recommendation Structural Redesign – The Girder-Slab System - Open Web Dissymmetric Beam (D-Beam) - Composite Construction - Uses precast hollow-core slabs

Arlington, Virginia Michael Gray Structural Option Arlington Gateway Hotel Introduction Background Current Structure Alternate Systems Structural Redesign Cost and Scheduling Recommendation Design Loads – Flooring System - Corridors – 100 psf ASCE 7-02 Minimum Design Live Loads - Private Rooms - 40 psf Dead Load - 8” Hollow Core Plank – 56 psf - Concrete Leveling Topping and Grout – 4 psf Additional Live Load - Partitions – 15 psf

Arlington, Virginia Michael Gray Structural Option Arlington Gateway Hotel Introduction Background Current Structure Alternate Systems Structural Redesign Cost and Scheduling Recommendation Design of Floor Members - Spreadsheet Created With Member Properties Checked Precomposite Deflections and Stresses Checked Composite Loads - 4 Standard Sizes to select from with 8” slab DB 8x35; DB 8x37; DB 8x40; DB 8x42 Checked Compressive Stress of Concrete Checked Stresses in Bottom Flange Checked Shear Capacity of Web

Arlington, Virginia Michael Gray Structural Option Arlington Gateway Hotel Introduction Background Current Structure Alternate Systems Structural Redesign Cost and Scheduling Recommendation Conclusions Dead load deflection becomes an issue - Limited clear span Max span of 16’ when used with 28’ plank Use of tree columns - Solutions D-Beams can be made with camber

Arlington, Virginia Michael Gray Structural Option Arlington Gateway Hotel Introduction Background Current Structure Alternate Systems Structural Redesign Cost and Scheduling Recommendation How much will it cost? - D-Beams cost around 65 cents to fabricate - Standard wide flanges cost 35 cents to roll - Rising material and labor costs - 8” plank costs roughly $7.50/s.f. Structural SystemCost Per Square Foot Staggered Truss$25 CIP Flat-Slab$30 Girder-Slab$22 Assemblies Cost - Could save $2 million over CIP

Arlington, Virginia Michael Gray Structural Option Arlington Gateway Hotel Introduction Background Current Structure Alternate Systems Structural Redesign Cost and Scheduling Recommendation Scheduling - 15,000 s.f. per week - Superstructure constructed in just 15 weeks - Can place plank per day - Steel and plank erected at same time - 25% reduction in construction schedule

Arlington, Virginia Michael Gray Structural Option Arlington Gateway Hotel Introduction Background Current Structure Alternate Systems Structural Redesign Cost and Scheduling Recommendation Scheduling - Examples -Housing project at Princeton University superstructure finished in 4 weeks -8 story Drexel Dormitory superstructure finished in 31 days 2 5-story buildings with one crane Totaling 96,000 s.f.

Arlington, Virginia Michael Gray Structural Option Arlington Gateway Hotel Introduction Background Current Structure Alternate Systems Structural Redesign Cost and Scheduling Recommendation Recommendation – The use of Girder-Slab Technology - Reduced cost - Innovative use of steel - Reduces construction schedule over CIP - Reduces overall weight of structure by 40%

Arlington, Virginia Michael Gray Structural Option Arlington Gateway Hotel Introduction Background Current Structure Alternate Systems Structural Redesign Cost and Scheduling Recommendation Got Questions?