AE Senior Thesis 2009 U.S. Pharmacopeia Headquarters Consolidation Rockville, MD Analysis and Design of a Mild Reinforced One way slab with Post Tensioned Beams Jeffrey L. Rothermel Jr. The Pennsylvania State University Department of Architectural Engineering Structural Option

Discussion Topics Background Information Existing Structure Design Goals Project Stages and Process Structural Design Mechanical Ductwork Redesign AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option

U.S. Pharmacopeia Headquarters AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Owner: U.S. Pharmacopeia Architect: Hellmuth, Obata + Kassabaum (HOK) Structural: Cagley & Associates Inc. MEP: R.G. Vanderweil Engineers Construction: DPR Construction Inc. 6 stories - 91’ 191,000 ft 2 of new office and lab space New 19,000 ft 2 conference center Houses chemical and biological labs $69 million

U.S. Pharmacopeia Headquarters AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Showcase laboratory spaces Large open office plans Kitchenettes for employees at every floor Curtain wall, metal paneling, and beige split face CMU Conical auditorium with curtain wall skin Enclosed outdoor plaza space

Existing Conditions AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Two way mild reinforced concrete flat slab with drop panels 22’x22’ column grid 14’ floor-to-floor heights (Typ.) Reinforced concrete moment frames Steel framed conference center Truncated, conical concrete auditorium Photo courtesy of HOK Inc.

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option

Design Goals AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Lower floor-to-floor heights from 14’ to 13’ Increase column grid from 22’ to 44’ Eliminate moment frames Reduce ductwork sizes Maintain existing ceiling height

Design Stages AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Investigate 3 alternatives Choose optimum system Design chosen floor system Design matching lateral system Resize ductwork mains

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Possible Solutions Staggered Steel Truss system Taken From AISC Design Guide 14: Staggered Steel Truss Framing Two way post tensioned slab One way slab with post tensioned beams

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Structural Depth Design Design Process 1.Lay out beams 2.Design slab system 3.Design post tensioned beams 1.Size 2.Tendon quantity 3.Drape 4.Column check 5.Design shear walls 1.Shear reinforcement 2.Flexural reinforcement 3.Coupling beams

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option One way slab with PT beam design New Beam Layout

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option One way slab with PT beam design Slab Design One way reinforcing 7” slab typ. 7-1/2” slab at 250 psf loading #5 bars T&B 24” for shrinkage and temperature parallel to beams

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option One way slab with PT beam design Designed with RAM Concept per ACI Spans extended to 44’ Shallow wide beams Existing column size kept (24”x24”) F ’ c = 6000 psi Class T Transitional T-Beam properties #6 Bottom at ρ min = #5 Top with no minimum reinforcement 0.6f ’ ci compression limit (18.4.1(a)) 7.5√f ’ c ≤f t ≤ 12√f ’ c tensile stress limit (18.3.3)

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option One way slab with PT beam design Design Process 1. Size the beams 2. Add tendons 3. Check stresses 4. Adjust profile 5. Schedule

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option One way slab with PT beam design Interior beams typically 48”x14” Edge beams typically 30”,32”x14” tendons interior typically tendons in edge typically

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option One way slab with PT beam design Transfer Girders 16-30” deep at transfers 48-56” wide at transfers Same depth as existing transfers 20-50% more post tensioning

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option One way slab with PT beam design Load Balancing Load Balancing (% DL) Span FloorCol Line FirstA B C D E F G SecondA B C D E F G ThirdA B C D E F G FourthB C D E F G PenthouseB C D E F G Balance % of dead load Target balance 60-90% Target met in most beams A few beams overbalanced Some underbalanced

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option One way slab with PT beam design Existing Column Properties Checked using PCA Column Moments from RAM Concept at column Interior columns sufficient Exterior columns require increased rebar Required for increased moment 8#9 12#9

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Shear Wall Design Existing reinforced concrete moment frames

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Shear Wall Design

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Shear Wall Design Taken From ASCE 7-05 Load Determination Method 2 per ASCE wind cases investigated Seismic loads using Equivalent Lateral Force Method 18” trial thickness 1.6W vs. 1.0E

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Shear Wall Design Shear reinforcement as required per Sec Each wall/segment designed for shear and flexure separately Minimum shear reinforcing used None needed for shear strength #4s Typ. Moment controlled reinforcing designs #8s Vert. for flexure

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Shear Wall Design Deflections in SAP 8” Membrane Self mass included 24” mesh Full I values for all members F ’ c = 3000 psi Wind limitation H/400 Seismic limitation 0.02h xn

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Shear Wall Design Coupled shear wall design SAP Member self weight included 8” Membrane Coupling beams extend into wall face 2’ Rigid end offset 48” deep beams Coupling beams as deep beams per Sec Designed per Sec Shear reinforcement per Sec. 11.7

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Mechanical Ductwork design Design Goals Keep loss under.25” WC/100’ Keep fpm flow under 2500 in mains over occupied spaces Reduce height and increase width

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option First Floor Mechanical Ductwork Redesign

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Mechanical Ductwork Redesign Vertical mains shrunk 8-20” per side Maximum horizontal run that travels under beams is 20” Minimum ceiling height is 8’10” Average ceiling height can be +10’6”

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Façade Savings Floorsf curtain wallsf split face CMUsf metal panel 4th rd nd st Total $/sf Savings$4,309.92$3,933.80$1, Total Savings$9, Cost of New Ductwork Total Weightx1.15*xCost (installed) ($/lb)=Total Cost 42,263.2x1.15x6.79=$330,012 Cost of Existing Ductwork Total Weightx1.15*xCost (installed) ($/lb)=Total Cost 53,749.2x1.15x6.79=$419,700 Savings From Changes$89,688 *15% added for brackets and supports Some Quick Costs Savings on façade and ductwork More expense on structure

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Project Summary Post tensioned beam system provides optimal performance Wide shallow beams incorporate desired attributes into floors 48”x14” for most interior beams and 30”x14” for most exterior 8” shear walls designed for moment Mechanical ductwork redesigned to obtain project goals Savings on façade and mechanical ducts, more cost in structure All goals reasonably attained

AE Senior Thesis 2009 | U.S. Pharmacopeia Headquarters | Jeffrey L. Rothermel Jr. | Structural Option Questions/Comments