East Monroe Garage

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REPAIR AND PREVENTATIVE MAINTENANCE OF THE EAST MONROE PARKING GARAGE

Chicago, Illinois


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REPAIR AND PREVENTATIVE MAINTENANCE OF

THE EAST MONROE PARKING GARAGE

Chicago, Illinois

Project Abstract

The Repair and Preventative Maintenance

o the East Monroe Parking Garage was a

ast paced 15-month renovation project in

the heart o downtown Chicago.

The underground parking acility is located

below Grant Park and covers a oot print

o 760 eet wide by 1200 eet long. The

parking garage is part o the largest

parking system in the United States and

has three levels with two underground

parking levels accommodating 3,850

vehicles.

The garage has been in operation or

almost our decades and has exterior and

interior structural elements that were

severely deteriorated. The entire garage

received upgrades including extensive

concrete repairs, new waterproofng

systems, new elevator, escalators, HVAC,

and renovations to the North Lobby.

One o the most crucial aspects o the

project was the hydro-demolishing o the

concrete deck on the upper level o the

parking garage and replacing the concrete.

There are only a hand-ull o contractors

in the country that specialize in hydro-

demolition.

PROJECT ABSTRACT


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Chicago, Illinois

Sustainability Initiative

East Monroe Parking Garage project

required the collection, treatment, and

re-use o over 11 million gallons o water

resulting rom the hydro-demolition

process. The team hired an independent

testing agency to treat and test the water

to ensure compliance with any City o

Chicago water quality standards prior to

depositing any waste water into the storm

or sanitary sewer system. Testing o the

waste water was done every 14 calendar

days. Prior to releasing waste water of-

site, waste water was run through settling

tanks and then ltered to remove particles

in excess o 100 microns. Once the water

had passed through the lter system, it

was then be treated to reduce the PH level

to meet discharge requirements. No water

was released until tests indicated that the

waste water met requirements stipulated

by the City.

SUSTAINABILITY INITIATIVE


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Chicago, Illinois

Project Description

The East Monroe Parking Garage was

originally constructed in 1974. It is a three

level acility with two underground parking

levels to accommodate 3,850 vehicles.

The acility includes about 1,470,000

square eet o garage space. Along with

three other related parking acilities, they

provide over 9,000 parking spaces beneath

Chicagos Millennium and Grant Park in

downtown Chicago and adjacent to Lake

Michigan.

The East Monroe Garage has a 753 x

1179 ootprint. The top (roo lid) level

supports Maggie Daley Park. This 20+

acre park is currently under renovation

and when completed in 2015, will eature

multisensory landscaping, an ice skating

ribbon, rock climbing sculptures, play

gardens and multiple event spaces.

STRUCTURE CHARACTERISTICS

CAUSES OF DETERIORATION / PROBLEMS THAT PROMPTED REPAIRThe parking garage has been in operation

or almost our decades. Exterior and

interior structural elements were

severely deteriorated rom seasonal and

environmental exposure. This exposure

caused corrosion damage to the concrete

walls, columns, slabs, and ceilings.

Structural condition surveys discovered

that much o the concrete had extensive

deterioration, delamination, and spallingon the suraces. The majority o the

deterioration was due to corrosion o

embedded top reinorcing steel and a

chloride contaminated environment.

The structural slab consists o 9-inches

o conventionally reinorced concrete.

There were a variety o traf c bearing,

waterproong systems o dierent

vintages on the top oor suraces.

All existing top reinorcing steel was

deteriorated and in need o replacement.

Cracks in the concrete leaked severely,

exposing portions o the structure to bothtopside and underside deterioration.


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Chicago, Illinois

Project Description

INSPECTION/EVALUATION METHODS AND TEST RESULTS

Preliminary recommendations included

complete slab replacement in all areas

o the structure. Indeed, extensive ull

depth deterioration was noted in primary

areas such as the entrance/exit lanes and

primary drive lanes and ramps. However,

the extent o the deterioration was visually

less in parking module areas. Additional

testing (chloride and corrosion hal cell

potentials) at the underside o many

slab areas revealed little or no chloride

contamination or corrosion potentials.

Accordingly, the engineering rm designed

a unique approach that incorporated

hydromilling to remove the chloride

contaminated portions o the slabs. A

combination o ull depth repairs and a

partial depth overlay was adapted as a cost

eective, long-term repair approach while

updating the structure to meet the current

requirements o the Chicago Building

Code.

A new, (dry) sprinkler re suppression

system and re doors were installed. These

new eatures provided an added benet

in that it permitted the removal o every

other re separation wall to create new

open areas o 80,000 square eet versus

the original 40,000 square eet, enhancing

the parking experience rom a site visibility

and security standpoint.

SITE PREPARATION

The original plan called or the

underground garage to remain partially

open during the restoration but, due

to the ast-track nature o the project

and the logistical dif culties in de-

commissioning existing lie saety systems

in an underground structure and bringing

all new lie saety systems on line in re-

opened areas, a dierent approach was

pursued. It was decided that the acility

would be closed and the work would

proceed in the shortest possible time.

The goal was to complete the project in

approximately hal the original allotted

time. Beore work could begin, all vehicles

were cleared rom the acility. Additional

site preparation measures included

creating a detailed logistics plan, which

was a challenge since crews needed

to share an entrance with an adjacent

garage that remained open at all times. All

pumping equipment and trucks needed to

saely stay out o the way o live traf c.


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Chicago, Illinois

Project Description

DEMOLITION METHOD

Hydro-demolition (milling) was chosen

as the most ef cient approach. The

combination o underground work

and hydro-demolition posed distinct

challenges not typically present in most

projects. The roaring noise coming rom

the specialized equipment was over

100 decibels, creating a communication

challenge. Furthermore, 36,000 psi o water

pressure was used to selectively remove

portions or all o the slab surace. Hand

chipping was perormed around columns

and drop head using 15 lb. air hammers.

The use o hydro-demolition equipment

required us to enorce special saety

precautions. Faceshields, saety glasses,

and walkie-talkies kept our crews sae and

in constant communication.

Since the garage consists o two parking

levels (upper and lower levels), all hazards

were prevalent on the upper levels

due to holes that were a result o blow-

throughs (a.k.a. ull depth removal). Nets

were erected at areas adjacent to hydro-

demolition work to separate and protect

workers.

SURFACE PREPARATION

Ater the completion o the hydro-demolition, rebar was inspected to meet

the criteria in the specications. Any bar

that did not meet specs was removed.

To ensure proper bonding, workers

APPLICATION METHOD SELECTION

Each ull depth area was ramed, and new

epoxy-coated steel was installed in the

top mat o reinorcing throughout as well

as in the bottom mat in ull depth areas.Concrete was placed rom the top surace

through air shats by truck pumps. A pipe

system was brought in to be used once

underground to transport the concrete to

the placement area. From that point, the

slabs were water cured according to the

specications.

sandblasted partial depth areas. Thesurace was then cleaned by blowing and

vacuuming to eliminate any oreign matter

that might interere with adhesion to the

existing slab.

To ensure the longevity o the new

structure, low water-cement ratio concrete,

epoxy coated steel and a polyester

reinorced hot rubberized waterproongmembrane was placed over the water

cured slabs. This high perormance

waterproong system was then protected

by a minimum 1 inch thick, asphalt

paved driving surace. The new slab

suraces were shot blasted clean to ensure

proper bond o the membrane to the slab.


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Chicago, Illinois

Project Description

REPAIR PROCESS EXECUTION

Debris rom the demolition had to be

moved in order to place the shoring or the

rame work. The surace o partial depth

areas were sandblasted and cleaned.

The next step o the process was saturating

the surace with water, covering it with wet

burlap, and then covering it with plastic to

retain the moisture or a minimum o 24

hours. The plastic and burlap was peeled

back one bay ahead o the pour on the day

o placement. The slabs were poured in

14-oot bays at an average o 18,000 SF per

pour. The surace was then wet cured using

the burlap and plastic rom the SSD.

The north exterior wall showed severe

deterioration rom years o exposure to

moisture and de-icing slats that leaked

through a ailed expansion joint rom

the public sidewalk area above. The

delaminated concrete was removed

rom the wall, surace then sandblasted,

inspected, and new reinorcement was

placed. The wall needed to be ramed and

saturated until placement. The concrete

was placed mainly by truck pumping sel-

consolidating concrete along with hand-

mixed material into a ramed cavity. All the

work was done o o swing stages.

UNFORESEEN CONDITIONS FOUND

Unexpected and unoreseen conditions

that presented unique challenges to our

team included re-shoring column drop

heads due to the extensive amount o ull

depth repairs which compromised the

drop head connection to the existing oor.

A complete re-design o re suppression

systems was necessary based on the City

o Chicago requirement o a two sourced

water supply or the or the dry sprinkler

system which involved direction boring to

tap into the waterline rom Monroe Street.

Another unique challenge special to

the East Monroe Garage project is its

ventilation, lighting, communication, and

egress based on its underground location.

The accelerated project schedule created

a unique challenge. The schedule called

or us to complete the project in 455 days

so working through the winter months

was a must. Additionally, working in the

heart o the City o Chicago presented

many logistical challenges. There was a

time period during the winter months

were we worked 24 hours a day due to

cold and reezing temperatures which

made job conditions extremely dif cult to

manage. Controlling the water usage and

collection while allowing proper drainage

throughout the reezing temperatures was

a challenge.


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Chicago, Illinois

Project Description

The Repair and Preventative Maintenance

at the East Monroe Street Parking Garage

revitalized an essential commuter hub in

downtown Chicago.

This project was extremely unique due

to the act it was entirely underground.

Ventilation, temporary lighting, wireless

phone usage, and ingress/egress to

the site are typically not a cause or

concern on most projects. But being

underground is a dierent scenario.

Maintaining proper ventilation and

lighting were major concerns. Supply

and exhaust ans surrounding the garage

were monitored daily to ensure they

were unctioning properly and carbonmonoxide levels were monitored regularly.

Without proper ventilation, none o

Other signicant unoreseen conditions include:

Micro silica overlay on existing slab entrance required removal

Amount o unreinorced and/or under reinorced drop heads

Total area repaired on the North wall increased by thousands o SF

UNFORESEEN CONDITIONS FOUND - continued

SPECIAL FEATURES THAT MAKE THE PROJECT WORTHY OF AN AWARD

the machines and equipment could be

used. The main culprit, o course, was

the hydro-demolition machine. Not only

did it exhaust a large amount o carbon

monoxide, it also emitted a lot o heat

and introduced a tremendous amount o

moisture into the air. When these machines

were running at ull capacity, a mist ormed

around it causing humidity and visibility

concerns in the area and the water spray

guns only made things worse. Blowers/

ans were situated at these areas to combat

these hazards. An ice box was provided to

battle heat exhaustion among the workers.

Also, additional land-lines were installed

at various locations within the garage.

All o these measures ensured a sae andsuccessul project.


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Chicago, Illinois

Project Description

Unique demolition and concrete repair to a below ground structure

Restoration to a acility incorporating long-term solutions that will last the test o time

Repair o corrosion and moisture damage to an entire concrete structure and exterior

vertical walls

Working under unique and hazardous conditions, on a scale that has never in history been

seen on an underground parking structure

Unique solutions to unexpected and unoreseen conditions

Extradited work schedule that was completed in a short amount o time

Replacement o concrete at the parking entrance where there was live traf c

Volume o water and debris rom lower-level demolition completely removed

Totals o 15,000 yards o concrete, over 600 tons o steel and pumping rom the top

surace underground with pipe that runs as long as 1,200 eet

As part o the park renovation project over the garage, a complete membrane tear o and

re-waterproong o the top level was perormed

WHAT SETS THIS PROJECT APART?

Full Depth Replacement: 234,000 SF

New Concrete Overlay Replacement: 800,000 SFOVER 1,000,000 SF

Overhead Repairs: 5,000 SF

Vertical Repairs to the North Wall: 13,000 SF

Yards of Concrete: 15,000

Pounds of Steel: 1,432,000

East Monroe Garage is the largest of the four garage parking system that

makes up the largest underground parking system in the world.


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Date post:	14-Apr-2018
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East Monroe Garage

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