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Home My WebLink AboutCO 7 CAG-18-002, CO #7-19 0 As % ( + "T° Change Order No. 7 Contract Title: N 27th Place Bridge Scour Repair Project Contractor: SB Structures, LLC Contract No. : CAG 18-002 Federal Aid No. : BHOS-1070(010) ® Ordered by Engineer ❑ Proposed by the Contractor(VECP) ❑ Unilateral Original Contract Amount: $444,783.22 i, Current Contract Amount: ;r418,003.14 /4/8, 6Z4.45 41Ul lii Estimated Net Change This Order: $0.00 , New Contract Amount: $418,303.14 9$4/8,6 Z4.45 8/OI 'i) Prep ed By: ass By: ` -Rtsidt1 it-Ci igii feei Date ngin r(City of Renton Transportation ate 6i7'y 0-( Rt444h Prjec.4 Mar t•tje_r- Design Manager) Reviewed By: Consent By: SiSe..i_k_ 9/2Y fil Fgineer of Record Date Surety(Greater than 25%cost and/or 20% Date time increase) Reviewed By: Endorsed By: City of Renton Pfejeet Manager Date Contractor Date %rAIns. >es;yN Executed By: Reviewed By: / yy/ q F///7g70I�^ g127//�1 City Attorney(Greater than$35,000 Date Cite enton Public Works Date and/or change in scope) Administrator/Mayor Change Order No. 7 Contract Title: N 27th Place Bridge Sour Repair Project Contract No. CAG-18-002 Page 1 of 5 THE CONTRACT IS MODIFIED AS FOLLOWS: Description of Change: • Revise Special Provision Section 8-19.1 Description. 8-19.1 Description This work consists of furnishing, mixing, and placing streambed aggregates, of the type specified, at the locations and in conformity with the lines and dimensions shown in the plans or established by the Engineer. Streambed aggregates are classified as follows: Streambed Sediment Streambed Cobbles 12 in. 4 in. Streambed Boulder One Man • Revise Special Provision Section 8-19.2 Materials. 8-19.2 Materials Materials shall meet the requirements of the following sections: Streambed Aggregates 9-03.11 Streambed Sediment 9-03.11(1) Streambed Cobbles 12 in. 4 in. 9-03.11(2) Streambed Boulder One Man 9-03.11(3) • Revise Special Provision Section 8-19.5 Payment. 8-19.5 Payment "Streambed Sediment", per ton. "Streambed Cobbles 12 i .4 in.", per ton. "Streambed Boulder One Man", per each. The unit Contract price per ton for the Streambed Sediment, Streambed Cobbles and Streambed Boulder, specified above shall be full pay for furnishing all labor, tools, equipment, and materials to install these materials as shown in the plans and required in these specifications. Payment shall be made for the quantity of materials actually placed. • Change Order No. 7 Contract Title: N 27th Place Bridge Sour Repair Project Contract No. CAG-18-002 Page 2 of 5 Reason for Change: Pursuant to contract CAG-18-002, a mixture of streambed cobbles and streambed sediment was to be placed inside the existing culvert along with streambed boulders one man. Special Provision Section 8-19 Streambed Aggregates specified Streambed Cobbles 12 in. Submittal No. 17 included a Request for Approval of Material (RAM) for drain rock and streambed aggregates. The Contractor sent the submittal via e-mail on August 10, 2018 to the Construction Management Consultant for review. The RAM listed Bid Item No. 28 Gravel Backfill for Drain, Bid Item No. 43 Streambed Cobbles 12 In., and Bid Item No. 44 Streambed Sediment. The submittal was returned to the Contractor on August 13, 2018. The response on the Transmittal cover was "Exceptions Noted—Resubmit Streambed Cobbles 12-inch". A revised submittal for Streambed Cobbles 12.was not found in the project construction documentation. The Inspector Daily Report (IDR) dated September 10, 2018 states that the Contractor's Work Activity for the day included "43: STREAMBED COBBLES 12 IN. (TON) — 44: STREAMBED SEDIMENT (TON) — See previous ticket, streambed agg was delivered without sediment. One truck of pure sediment is going to be delivered onsite tomorrow morning for onsite mixing." The IDR also states "12:06 PM First load of mixed delivered truck 88 — Scarsella = 43: STREAMBED COBBLES 12 IN. (TON) —44: STREAMBED SEDIMENT (TON)". However, the images included in the IDR contain one photo of a truck ticket for Streambed Cobbles 4 In. The time stamp on the photo is 12:06 PM. The photo includes a tag which states "Does Not Meet Specifications". No further explanation provided in the IDR. The IDR was signed by the inspector. No reviewer signature listed. No other information was found in the project construction documentation regarding the streambed cobbles. Streambed Cobbles 4 In. was incorporated into the project. Payment for this material was included in Progress Payment No. 3, prepared by the Construction Management Consultant. The purpose of the project is to install scour protection for the culvert footings. Light loose riprap placed around the culvert footings fulfills this purpose. The void spaces in the light loose riprap were filled with streambed sediment via washing. Filling the void spaces was required to prevent loss of a stream with a free surface. Other streambed materials, placed on top of the light loose riprap layer, (e.g. boulders and mix of cobbles/sediment) created a new stream channel that approximates native conditions. Given the steep grade of the stream profile through the culvert, the streambed cobbles specified for the project were 12 in. per WSDOT Standard Spec. 9-03.11(2). The intent for using this cobble size was to minimize the potential of the cobbles migrating downstream. The streambed cobbles placed for the project were 4 in. per WSDOT Standard Spec. 9-03.11(2). The gradation for the 4 in. includes smaller diameter materials, which are more consistent with the existing native materials found within the existing stream channel. While the smaller diameter materials are more likely to migrate downstream, the underlying light loose riprap layer will continue to provide scour protection for the culvert footings. The concrete cutoff wall constructed inside the downstream end of the Change Order No. 7 Contract Title: N 27th Place Bridge Sour Repair Project Contract No. CAG-18-002 Page 3 of 5 culvert, spanning between the footings, will limit the amount of future channel incision inside the culvert. Therefore, while the smaller diameter materials may more readily migrate downstream than larger diameter materials, the underlying scour protection will remain intact and protect the culvert footings from scour. There is a small dam located upstream from the culvert that has starved the stream system of smaller diameter gravels and cobbles over many years. Aside from the few boulders, cobbles and gravels uncovered through channel incision, only fine sediment is transported downstream from the dam. One benefit of placing the smaller diameter material in the newly constructed stream channel is that it temporarily recharges the system with gravels and cobbles, downstream from the culvert. This should reduce the rate of channel incision in the culvert for the short term as these materials reach equilibrium within the stream system. Over a longer span of time, channel incision will eventually resume. Regardless, light loose riprap placed between the footings combined with the concrete cutoff wall constructed inside the culvert will minimize channel incision within the culvert, keeping the footings scour safe. Materials: N/A Plans: N/A Adjustment: This Change Order includes changes as defined in Section 1-04.4. Specifically, altering specifications. Extension of Time: The Time for Completion is extended 0 non-compensable Working Day in accordance with Section 1-08.8. Equitable Adjustment: This Change Order does not include an equitable adjustment by agreement with the Contractor. Change Order No. 7 Contract Title: N 27th Place Bridge Sour Repair Project Contract No. CAG-18-002 Page 4 of 5 Sections 1-04.4 and 1-04.5 of the 2016 WSDOT/APWA Standard Specifications shall govern this Change Order.The Work of the referenced Contract is modified to include the changes detailed herein.The payment provided for herein shall constitute the complete and final settlement for all costs of labor,equipment, materials, overhead, profit, permit fees,and all other claims that may lie made by the Contractor as a result of this change. Attachments: Forms to be attached to Change Order ❑ Plans ❑ Field Directive ❑ Change Order Quotation • Estimated Change Order Cost • Project Labor List O Force Account Equipment Rate Request(DOT Form 422-010 EF) ❑ Equitable Adjustment Determination Change Order No. 7 Contract Title: N 27th Place Bridge Sour Repair Project Contract No. CAG-18-002 Page 5 of 5