99-312 Resolution No . 99-312
RESOLUTION
APPROVING CHANGE ORDER NO. 1 IN THE CONTRACT WITH
KOVILIC CONSTRUCTION COMPANY, INC. FOR THE
KIMBALL STREET DAM REHABILITATION PROJECT
WHEREAS, the City of Elgin has heretofore entered into a
contract with Kovilic Construction Company, Inc . for emergency
repairs on the Kimball Street dam as part of the Kimball
Street Dam Rehabilitation Project ; and
WHEREAS, it is necessary and desirable to modify the
terms of the contract as is described in Change Order No. 1,
attached hereto.
NOW, THEREFORE, BE IT RESOLVED BY THE CITY COUNCIL OF THE
CITY OF ELGIN, ILLINOIS, that Joyce A. Parker, City Manager,
be and is hereby authorized and directed to execute Change
Order No. 1, a copy of which is attached hereto and made a
part hereof by reference.
s/ Ed Schock
Ed Schock, Mayor
Presented: December 15 , 1999
Adopted: December 15 , 1999
Omnibus Vote: Yeas 7 Nays 0
Attest :
s/ Dolonna Mecum
Dolonna Mecum, City Clerk
ELGIN, ILLINOIS
PROJECT 338438
CHANGE ORDER No. 1
SCOPE: This Change Order No. 1 will provide additional items necessary to complete the
emergency repairs on the Kimball Street Dam as part of the Kimball Street Dam Rehabilitation
Project. These items were not foreseen at the time the initial contract was awarded.
The general contractor for this project is Kovilic Construction Company, Inc. of Franklin Park,
IL.
REASONS FOR CHANGE: This Change Order No. 1 is in the best interests of the City and is
authorized by law.
SUMMARY OF CHANGES IN CONTRACT AMOUNT: The amount the contract will be
revised is as follows:
ITEM UNIT PRICE QUANTITY TOTAL
Mobilization $39,150.00 LS $ 39,150.00
Cofferdam $83,900.00 LS $ 83,900.00
Concrete $655.00/CY 188.66 $123,575.00
Concrete Anchors - 24 in. $34.00 Ea. 262 $ 8,908.00
Concrete Anchors - 18 in. $18.00 Ea. 891 $ 16,038.00
TOTAL $271,571.00
The original contract with Kovilic Construction Company is $923,412.00. By reason of Change
Order No. 1, the contract for the Kimball Street Dam Rehabilitation Project will be increased in
the amount of two hundred seventy one thousand five hundred seventy-one and 00/100 dollars
($271,571.00). The new contract amount, inclusive of Change Order No. 1 is one million one
hundred ninety four thousand nine hundred eighty-three and 00/100 dollars ($1,194,983.00).
CHANGE ORDER No.!
November 22, 1999
Page 2
OTHER CONTRACT PROVISIONS: All other contract provisions shall remain the same.
Agreed to this 6 day of X)( C , , 1999.
Recommended:
ENGINEERING DIVISION
By:
Title:
Date: f/ 2.2- ?
Accepted:
KOVILIC CONSTRUCTION COMPANY
Party of the Secon Part (Contractor)
By: .
Title:
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Date: I PL. Z - 59
Approved:
CITY OF ELGIN
Party of the First Part Owner)
By:(1, a. the
1
Title:
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Date: /y,)- 0/7/
•��OF c4C
V.,
City of Elgin
Agenda Item No.
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November 22, 1999
TO: Mayor and Members of the City Council
FROM: Joyce A. Parker, City Manager
SUBJECT: Kimball Street Dam Rehabilitation
Change Order No. 1
PURPOSE
The purpose of this memorandum is to provide the Mayor and members
of the City Council with information for approval of Change Order
No. 1 for emergency repairs to the Kimball Street Dam.
BACKGROUND
The City Council, at its May 26, 1999 meeting, awarded the contract
for the Kimball Street Dam rehabilitation project to Kovilic
Construction Company, Inc. The original project included repairs
to the fish ladder at the west end of the dam, repair to old
construction joints, filling voids at the toe of the dam,
constructing a structural cap over approximately 100 feet of the
east face of the dam and grout injection of the interior of the
dam. The project began on August 16, 1999 and was substantially
completed on October 29, 1999 . A location map is attached as
Exhibit A.
On Wednesday, November' 10, 1999, several cracks developed on the
downstream face of the dam. This superficial failure occurred near
the center of the dam and extended for a length of approximately 64
feet . This section of the dam face was not included in the
original scope of work. However, repairs were made at the toe of
the dam in the affected area to fill larger voids that had
developed over time .
An inspection conducted on November 12 , 1999 revealed that the
existing dam face consisted of two concrete slabs of approximately
six inches in thickness each. The inspection also revealed that
bonding between these two layers of concrete was poor. The
condition of the underlying concrete slab indicates that water has
been flowing between the slabs for several years. It appears that
prior to repairs made to the toe of the dam, water could flow
freely between the two concrete slabs . Once repairs were made,
water could no longer flow through the layers, resulting in an
increase in pressure on the top concrete layer and ultimately in
its cracking and failure.
•
•
Kimball Street Rehabilitation Change Order No. 1
November 22, 1999
Page 2
A copy of the report discussing the failure that occurred to the
dam is attached as Exhibit B. This report was written by Collins
Engineers, the engineering firm hired by the City to oversee the
rehabilitation of the dam. The report includes the recommendation
that the remaining portion of the dam face that was not overlayed
as part of the original contract with Kovilic Construction be
completed. This will uniformly extend the useful life of the
entire dam to the 30 to 50-year range.
COMMUNITY GROUPS/INTERESTED PERSONS CONTACTED
//'' None .
T` L4'INANCIAL IMPACT
• The estimated cost to complete the emergency repairs to the Kimball
Street Dam is $321, 571 . Originally, monies totaling $1, 050 , 000
were in account number 275-0000-791. 92-36, project number 338438 .
Encumbrances to date total $994, 248 leaving $55, 752 in unencumbered
funds . It is also estimated that the original contract with
Kovilic Construction Company will be completed for $50, 000 less
than the awarded amount . Therefore, $105, 752 is available to
partially fund the additional work. The remaining amount of Change
Order No. 1 ($215, 819) can be funded from greater than anticipated
Riverboat Lease proceeds, account number 276-0000-791 . 92-36 . The
actual amount of Change Order No. 1 will be $271, 571 ($321, 571 -
$50, 000 in savings from the original contract with Kovilic
Construction) .
The emergency repairs were authorized by the City Manager on
November 18, 1999 . The contractor has already begun work
associated with Change Order No. 1 and estimated that work will be
completed in approximately three weeks.
A copy of Change Order No. 1 is attached as Exhibit C.
LEGAL IMPACT
Mill/ None .
ALTERNATIVES
None .
r
rft. Kimball Street Rehabilitation Change Order No. 1
November 22 , 1999
Page 3
RECOMMENDATION
It is recommended that the City Council authorize execution of
Change Order No. 1 in the amount of $271, 571 . The new contract
amount with Kovilic Construction Company, Inc . will total
$1, 194 , 983 .
Respectfully submitted,
.,. - 4 P
oyce A. Parker
City Manager
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COLLINS ENGINEERS, INC .
CIVIL, STRUCTURAL, WATER RESOURCES AND UNDERWATER ENGINEERING
November 18, 1999
Job No. 2172
Kimball Street Dam
Mr. Steven Pertzborn, P.E.
City of Elgin
150 Dexter Court
Elgin, Illinois 60120-5555
Dear Mr. Pertzborn:
BACKGROUND
On Wednesday, November 10, 1999, several cracks were noted in the concrete slabs on the
downstream face of the Kimball Street Dam. The cracking was accompanied by vertical and
horizontal slab displacement. Slab cracking and displacement extended across a 64-foot
length from Station 1+36 to Station 2+00. Photographs 1 through 4 show the cracking and
displacement and Figure 1 shows the location.
During the summer and fall of 1999, repairs were made to the Kimball Street Dam. Repairs
consisted of grouting the rockfill beneath the overlying concrete slabs, constructing a
concrete apron along the downstream toe of the dam from Station 0+00 to Station 2+00,
and constructing a concrete overlay on the downstream face of the dam from Station 0+00
to Station 0+96. Figure 1 shows the location of the 1999 repairs.
CAUSE OF DISTRESS IN SLABS
The contractor who made the 1999 repairs reinstalled the upstream cofferdam on Thursday,
November 11, 1999. On Friday, November 12, 1999, flow over the distressed area was
reduced so that the cracking and displacement could be examined and documented.
Additionally, an underwater inspection of the dam was made and a crest elevation survey
was performed. The damaged slabs were removed on Friday, November 12, 1999.
The damaged slabs ranged in thickness from approximately 3 inches to 8 inches. The slabs
that were removed overlay another concrete slab. The removed slabs contained welded wire
reinforcement and were not anchored to the underlying slab. There was minimal bonding
between the overlay and underlying slab. Most of the surface area on the bottom of the
removed slabs and the top of the underlying slab was stained indicating that water had been
211 WEST WACKER DRIVE • 8TH FLOOR • CHICAGO, ILLINOIS 60606-1217 • (312) 704-9300 • FAX: (312) 704-9320
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Mr. Steven Pertzborn, P.E. November 17, 1999 Page 2
flowing between these two slabs over a long period of time. Figure 3 illustrates the
condition of the two slabs.
Based on our examinations of the failed facing slabs, it is our opinion that before the 1999
repairs were made, water could flow between the slabs and under the slabs due to the poor
slab-to-slab bond and could exit along the downstream toe. After construction of the new
apron from Station 0+00 to Station 2+00, drainage of water was cut off along the toe. The
rock beneath the lower slab was grouted so that flow beneath the lower slab was
significantly reduced. The reduced flow beneath the lower slab and minimal flow through
the grouted rock was verified during the November 12th inspection.
After inspecting the damaged slabs, it appears that the voids between the two slabs allowed
water pressure (uplift) to build after the downstream apron was constructed. When the uplift
force exceeded the weight of concrete, the overlay cracked and moved upward. The initial
cracking appears to have occurred where the overlay was thinnest. The momentum of water
flowing over the dam then displaced sections of the cracked slabs. Additionally, after the
initial slab movement occurred, the flow lines were no longer smooth and uniform. This
allowed the flow to separate from the concrete causing a negative pressure which can cause
additional uplift pressures and slab movement.
The inspection on November 12, 1999 did not reveal any distress in the grouted rock fill or
the foundation of the dam. Elevations of the crest were similar to previous elevations. It
does not appear that settlement has occurred. The downstream facing concrete next to the
damaged area is weathered but no evidence of distress was found. Additionally, based on
our periodic site visits during construction and the observed defective area, it does not
appear that the contractor's means or methods of construction or construction activity around
the dam contributed to the damaged section.
The presence of overlay slabs on the dam face and delamination of the overlay slab from the
underlying slab, the voids between the two slabs, the lack of anchorage of the overlay slab
to the underlying slab, and the flow of water through these voids was unknown when the
repairs were designed and constructed. During the 1997 inspection performed by Collins
Engineers, cores were taken through the crest of the dam and several holes were drilled
through the downstream face of the dam. Neither the cores or the drill holes revealed the
conditions now observed. In addition, there were no observable defects on the downstream
face at the time of the inspection that warranted a more extensive exploratory inspection.
RECOMMENDED REPAIR
At minimum, to repair the damaged section, a new concrete slab face should be constructed
from Station 0+96 to Station 2+00. The new slab should be anchored as shown on Figure
2. As holes are drilled into the grouted rock, the effectiveness of the grouting can also be
get
sfr
Mr. Steven Pertzborn, P.E. November 17, 1999 Page 3
verified. If any ungrouted areas are found during the drilling, additional grouting should
be done using only gravity flow.
The repair of the newly cracked facing, along with the previously completed face
reconstruction, will yield a refaced area of approximately two-thirds of the dam. Although
not required, we recommend that in order to uniformly extend the useful life of the entire
dam to the 30 to 50 year range, a new overlay slab should also be constructed from Station
2+00 to the Fish Ladder. Furthermore, refacing the remaining portion of the dam at this
time will reduce mobilization and cofferdam costs as compared to refacing this portion of
the dam in the future as a separate project.
There is an existing six feet wide apron along the toe of the dam from Station 2+00 to the
Fish Ladder. There has been no evidence of undermining in this area and riprap has already
been placed at the downstream edge. Therefore, we do not recommend widening the apron.
However, although not required, we recommend that the apron be raised three feet to
provide a smooth downstream flow transition from the new slab face. In addition, this will
bring the apron to a uniform height across the entire length of the dam.
Should you have any further questions or require additional information, feel free to contact
myself or Philip Schrieber at (312) 704-9300.
Very truly yours,
COLLINSS ENGINEERS, INC.
l?
Michael J. Garlich, S.E., P.E.
MJG/PAS/rm
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Photograph 1. Overall View of Kimball Street Dam, Looking Northeast.
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Photograph 2. View of Cracked Overlay Slabs, Looking East.
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Photograph 3. View of Cracked overlay Slabs, Looking West.
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Photograph 4. View of Cracked Slabs at Station 1+90. Note Debonding of the Overlay Slab from the
Underlying Slab.
■
FIGURE 3
1' Nominal
Cracked overlay
Original Concrete Slab
azo.
/\--- •.�•• Void with seepage
New
Concrete
Apron —\
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FAILED SECTION
NTS
Void before repairs
�! COLLINS ENGINEERS , INC .
CIVIL, STRUCTURAL, WATER RESOURCES AND UNDERWATER ENGINEERING
November 17, 1999
Job No. 2172
Kimball Street Dam
Mr. Steven Pertzborn, P.E.
City of Elgin
150 Dexter Court
Elgin, Illinois 60120-5555
Dear Mr. Pertzborn:
We have completed a cost analysis on repairs to the Kimball St. Dam. The analysis was
performed for two separate sections of repair. The first section consists of the damaged area
extending from Station 0+95 to Station 2+00 and the second section extends from Station
2+00 to Station. 3+28. Total estimated costs for the first and second sections are $133,925
and $187,646, respectively, resulting in a total estimated project cost of $321,571.
The breakdown of the costs can be seen on the attached table. The total cofferdam cost per
section is $41,950. This cost is less than the cofferdam costs for the original project repairs
because the contractor does not have to assume the risk of "Natural Acts of God" and
therefore based his cost on using a jersey wall type cofferdam system as opposed to the more
expensive "Port A Dam" system.
Higher anchor costs are being incurred due to the required use of deep anchors to anchor
the new slabs to the face of the dam. The original section of the dam that was refaced from
Station 0+00 to Station 0+95 provided a solid and sufficient base to anchor into. However,
the damaged section of the dam is comprised of deteriorated concrete and therefore requires
the use of deeper anchors to reach a sound material.
It should be noted that if the refacing of the west section of the dam is postponed until
sometime in the future, the cost to repair that section will increase due to the costs incurred
by having to remobilize and reconstruct the cofferdam.
V
KIMBALL STREET DAM
ESTIMATED REPAIR COSTS
Damaged Section West Section
(Sta. 0+95 to Sta. 2+00) (Sta. 2+00 to Sta. 3+28)
Mobilization Mobilization
Emergency Work $13,450 Riprap and Stone $7,500
Riprap and Stone $1,700 Concrete Demolition and Removal $1,000
Cold Weather Equipment $5,100 Equipment and Material Delivery $2,400
Concrete Demolition and Removal $3,000
Equipment and Material Delivery $5,000
$28,250 $10,900
Cofferdam Cofferdam
Barrier Wall $9,400 Barrier Wall $9,400
Fabric $7,300 Fabric $7,300
Sand Bags $4,100 Sand Bags $4,100
Dewater $6,150 Dewater $6,150
Labor $15,000 Labor $15,000
$41,950 $41,950
Concrete Concrete
Dam Face - 85yd3 @ $655/yd3 $55,675 Dam Face -95yd3 @ $655/yd3 $62,225
Apron - 85yd3 @ $655/yd3 $55,675
$55,675 $117,900
Anchors Anchors
70 -24"Anchors @ $34 Each $2,380 192 -24" Anchors @ $34 Each $6,528
315 - 18"Anchors @ $18 Each $5,670 576 - 18"Anchors @ $18 Each $10,368
$8,050 $16,896
TOTAL $133,925 TOTAL $187,646
TOTAL PROJECT COST $321,571
Page 2
Should you have any further questions or require additional information, feel free to contact
myself or Philip Schrieber at (312) 704-9300.
Very truly yours,
COLLINS ENGINEERS, INC.
� ir/
Michael J. Garlich, S.E., P.E.
MJG/PAS/rm
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