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HomeMy WebLinkAbout99-312 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: ` --- Date: I PL. Z - 59 Approved: CITY OF ELGIN Party of the First Part Owner) By:(1, a. the 1 Title: /i s2,-,,,,r. r Date: /y,)- 0/7/ •��OF c4C V., City of Elgin Agenda Item No. vit ri 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 KIMBALLSL DAM eft.•• • . . . ..... • . _ . I NORTH AvE NEL ) • ST S- �7 . .. - 400' T. ...... . ?,• • 5C 0 1,...") •11111111 li:C-':2 CI . ..-4,1--7:-4-:-..-- pax .� . ::_ DAM f 7[ g C2 s )__. z ..•.-_-....;.„ _.:,-.•....„ • 7 • V r--. 0 �A ` i l a rn .. .0 • r,` . �' DOUGLAS • f r r at O � 7,7 II a ,..-x r A i 1 i 1 x v y 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 G 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 E:\2172\PE6B76-1 W PD v j • r yes Photograph 1. Overall View of Kimball Street Dam, Looking Northeast. •••• r - r - _ • ea. . r Photograph 2. View of Cracked Overlay Slabs, Looking East. . . r .. „,,,,,, ,,,,. .,0,.... „. . ,,,,, , ,„ .n i t . �# �/ ids 4 Photograph 3. View of Cracked overlay Slabs, Looking West. r IMF. - fi i.y I'. xi.,.'tea v • . ' •_', ,- ,- a C. : e s ,- .-ar gym{ �`Y. *f J.. • a µ . c', `+ 4),A:spy' JV b.4�l4 �`4 v'r ,.�' �` s ;.•, z&_� �•'°-.` r+,iy. -7 "7-t ..-(40:;,-,-.!' s•, to t• • 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 —\ • - • . • .• - • -.• . • 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 E:\2172\CONSTR-1\COSTANAL.WPD