Terrell Place Washington D.C. - Pennsylvania State UniversityTracy Lo Construction Management Senior...

Tracy LoConstruction Management

Senior Thesis PresentationApril 16, 2003

Terrell PlaceWashington D.C.



Project Overview

� An 11 Story cast-in-place concrete office building � Location: 575 7th St NW

Washington D.C.� Function:

� Office Building� Retail space on 1st floor� Parking garage



Project Overview

� Size: 439,390 sq ft� Construction Date:

� Started in Aug of 2001� Finish in Oct of 2003

� Cost: $48.5 million

Existing Hecht’sBuilding

New WestBuilding

ExistingGang of Four

New BuildingNot in project

Existing AARP

Existing Building

Future Residential

Terrell Place

MCI Center

NRC

Firehouse

F street, NW

E Street, NW

7th street, NW

6th street, NW

N

Terrell Place - Site Plan



Project OverviewProject Team

� Owner: Carr America Urban Development LLC� GC: Clark Construction Groups� Architect/Engineer: SmithGroup� Mechanical Contractor: Pierce Associates, Inc.� Electrical Contractor: Truland Systems Corp.

Interesting FactNamed the Best Office Lease/Urban for 2001 in the Washington Business Journal’s Annual Best Real Estate Deals of the years awards with the largest law firm in Washington D.C.



Presentation Outline

� Site Logistic� Studies of Historical Renovation� Possibilities of Using other Horizontal

Formwork� Redesign the Foundation System� Research: Mold Issues in construction

industry



Site Logistic

Current Problem� Only one site plan developed

� Relatively congested site and narrow access road

Proposed Solution� Three phase site plans

� Clearly show the location of the equipments and access during different phases

� Create one way traffic flow

ExistingAARP BuildingExisting Restaurant

(5 story)

Future Residential(under construction)

Existing 5-story

building

Existing Site Plan

Sheeting/Shoring

Façade Support

Existing Hecht’s Building

(1 Basement)

Existing Gang of Four(to be demolished)

New West Building4 Basements

Sheeting/Shoring

Staging Area Curb Lane

Construction Safety Fence

Trash Chute & Dumpster

MaterialHoist

Entrance

ExcavationRamp

ConstructionTrailer

Temporary Access Road for

DemolitionDebris Removal


Temporary Pedestrian Sidewalk

Crane #1

Crane #2


(5 story)


Existing 5-story

building

Demolition/Excavation Phase

Façade Support

Existing Hecht’s Building

(1 Basement)

Existing Gang of Four(to be demolished)

New West Building4 Basements

Sheeting/Shoring




MaterialHoist

Entrance

ExcavationRamp

ConstructionTrailer

Temporary Access Road for

DemolitionDebris Removal



Sheeting/Shoring

ExcavationRamp


(5 story)


Existing 5-story

building

Superstructure Phase

Sheeting/Shoring

Façade Support

Hecht’s Building

Gang of Four

New West Building

Sheeting/Shoring




MaterialHoist

Entrance

ConstructionTrailer



Concrete Pump

Crane #1

Crane #2

Staging Area


(5 story)


Existing 5-story

building

Finishes Phase

Hecht’s Building

Gang of Four

New West Building

Curb Lane



MaterialHoist

Entrance

ConstructionTrailer



Mobile Crane




� Site Logistic� Studies of Historical Renovation� Possibilities of Using other Horizontal Formwork� Redesign the Foundation System� Research: Mold Issues in construction industry



Historical Preservation� Government of D.C. – Preservation law� 8 different types of windows on the façade and three different store front.

Study of the facade



Study of the facade

Problem� Long installation time

� Reason for delay

Proposed Methods� Combining Precast and window supplier

� But…..some windows are 10 feet high and 800 pounds, difficult for handling and shipping




� Site Logistic� Studies of Historical Renovation� Possibilities of Using other Horizontal

Formwork� Redesign the Foundation System� Research: Mold Issues in construction industry



Possibility of Using other Horizontal Formwork

� Three options

� Compare the cost and schedule for all the options� Each floor of the New West Building: 19,200 SF� Each floor of the GOF building: 12,000 SF

PERI skydeck with customized design

Original structural design

PERI skydeckNew structural design

Scaffolds and plywoodOriginal structural design

Construction methodsStructural changes



Original structural design using scaffolds and plywood (Option 1)

� Two way slab with drop panels� Original slab thickness: 8 in� Drop panels: 8 in� Plywood and aluma frames� Cost: $0.83 – $0.91 / sf

� Total cost of formwork and labor: $961,634

� Productivity rate:18-20 sf / mh� Duration of GOF: 104 days � Duration of West building: 164 days




New structural design using PERI skydeck (Option two)

� ADOSS program, determine slab thickness





PERI skydeck� Cost: $1.10 -$1.50 / sf

� Total cost and labor: $954,126

� Productivity rate: 20-30 sf / mh� Duration of GOF: 65 days � Duration of West: 113 days

� Impact of changing the formwork




Original Structure using PERI skydeck with customized formwork around the drop panels(option 3)

� Cost of the formwork: $1.39-$1.50 / sf� Total cost of formwork and labor: $1,128,574

� Productivity rate:18-20 sf / mh� Same as option 1




Comparisons of the original method and the two other alternatives:

Most expensive, relative slower rateNo changes in

structural designGOF –102 daysWest – 164 days

18-20sf / mh

$1,281,574$1.39-1.50/ sf

3 - Original design with drop panels using customized PERI Skydeck

Less plenum space, changes of structural design

Cheapestfastest method among the three options

GOF –65 daysWest -113 days20-30

sf / mh$954,126

$1.10-1.50/ sf

2 - Flat slab using PERI Skydeck

Relative slower rateTraditional method

GOF –102 daysWest – 164 days

18-20sf / mh

$961,634$0.83-0.91/ sf

1 - Original design with drop panels using stick build method

DisadvantagesAdvantagesDurationProductivity RateTotal CostCostOption



Analysis 4: Redesign the Foundation Systems

Problem� Spread Footings� Constructability issues:

� Difficult to construct the spread footings for this project due to the footings having different elevations adjacent to each other

� OSHA standard - sloping back around the excavation was necessary

Proposed System� Mat slab foundation




121333861107375000 psi

123506841479394000 psi

122652771093423000 psi

CostConcrete Unit Cost

VolumeThickness of Foundation (in)

Gang of Four

352959864107505000 psi

367177844397534000 psi

357405774642573000 psi

CostConcrete Unit Cost

VolumeThickness of Foundation (in)

West Building




Spread FootingsDisadvantages:

� More concrete is used for the GOF� Difficult excavation due to different elevations of the footings� Slow productivity during excavation, takes longer to excavate

Advantages:

� Less concrete is used for the West Building

� Less material (rebar, formwork)

� Allow to set rebar along the footings while formwork is being placed




Mat SlabDisadvantages:� Need to set rebar on site because of the amount of rebar� Large amount of concrete and rebar� One continuous pour, longer hours for workers� Heavy traffic due to 30-40 trucks per hour move through the site

Advantages:� Better constructability� Reduce duration by 10

days � Comparable cost as spread

footings



Research Topic:Mold Issues

Why are people looking into mold related problem in the construction industry?

� Litigation� Sickness related to mold

What is mold? What causes mold?

� A non-specific term of a type of fungus� Air borne� Moisture, food source, oxygen and warm temperature




Is Mold toxic?� Mold itself is not toxic� By products – mycotoxins will cause serious health

problem

Sickness Related to Mold� No medical evidence on mold in buildings lead to sickness � Allergic reactions

Studies of Court Cases� Property damage claims and personal injury claims� Pay millions of dollars




Lack of standards� No standards related to the level of mold exposure that is harmful to human� No inspection standards

What to do if mold if found?� Follow guidelines established by the EPA or AGC




What needs to be done related to this problem?� Need more development on medical field� Set up regulations and standards



Conclusion

Site Logistic� Important to create one way traffic within the site� More detailed site plans provide better

understandingStudies of Historical Renovation

� Good concept to combine the window and precastpanels suppliers

� But difficult to implement due to the special condition



ConclusionPossibilities of Using other Horizontal Formwork

� Prefabricated formwork for slab would be the best choice in terms of time and cost

� More changes of other structural components to increase the plenum space was necessary

Resign the Foundation System� Mat slab foundation will shorten the schedule by 10 days� Large amount of material and intensive work

Research: Mold Issues in construction industry� More government involvement is needed to set up the

standards



Thanks to

Clark Construction GroupTruland Systems Inc.

Dr. HormanDr. Messner

Dr. RileyAE faculty

Friends and FamilyDave

Terrell Place Washington D.C. - Pennsylvania State UniversityTracy Lo Construction Management Senior...

Documents

Transcript of Terrell Place Washington D.C. - Pennsylvania State UniversityTracy Lo Construction Management Senior...