1000.5e - 00901 - Addendum 1 - 20240412.pdf
PDF 11 MB Posted
- Attached to
- Mattie Dam Rehabilitation
- Solicitation number
- 2024-1
- Issued by
- Clear Creek County, Colorado
About this file
This document is Addendum No. 1 for the Mattie Dam Improvement Project in Idaho Springs, Clear Creek County, Colorado, issued by JVA, Inc. on April 12, 2024. The addendum modifies the original bidding and contract documents, providing clarifications and updates for the dam rehabilitation project. It includes responses to several pre-bid questions, updates to specific project sheets (C3.2, P1.0, and PD1.0), and attachments such as historical construction photos and a site map showing spoil locations. Key modifications include eliminating the concrete thrust block detail, specifying flowfill backfill requirements, and clarifying technical specifications for reinforcement, concrete, and pipe materials.
The addendum addresses technical details for bidders, including specifications for mud mat concrete (3,000 psi at 28 days), reinforcement (uncoated ASTM A615 Grade 60 bars), and 24" PVC pipe (C900 DR18). It provides guidance on site-specific requirements such as dewatering, stream flow diversion, and potential impacts to nearby wells, referencing Colorado Department of Natural Resources resources. The document indicates no pressure testing is required for the 24" PVC pipe, and pipe deflection testing will be specified in Section 02616.3.14.D. Bidders are instructed to acknowledge receipt of the addendum on the Bid Form, highlighting the importance of these technical clarifications for the dam improvement project.
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4/12/2024 00901-1 JVA 1000.5e
SECTION 00901
ADDENDUM NO. 1
PART 1 GENERAL
1.1 DESCRIPTION
A. This addendum forms a part of the Bidding and Contract Documents and modifies the
Project Manual and Plans as described below
B. This addendum consists of FOUR (4) pages in addition to the following attachments:
1. PHOTOS FOR BIDNET QUESTIONS
2. UPDATED VERSIONS OF SHEETS C3.2, P1.0, AND PD1.0
1.2 ACKNOWLEDGMENT
A. Acknowledge receipt of this addendum in the space provided on the Bid Form.
PART 2 QUESTION AND ANSWER
2.1 BIDNET
A. Bidnet Q1
1. Question: It was mentioned at the pre-bid that pictures could be provided of the dam when it was constructed. Please provide those pictures.
2. Answer: Photos attached below.
B. Bidnet Q2
1. Question: Burden soil was asked about at the pre-bid for a location to dispose of. How much burden soil can be disposed of across the road at the treatment plant? Where should other soil be expected to be hauled away to?
2. Answer: Attached image of spoil locations in order. We are not removing all of the sediment from the pond only what is necessary to construct the dam. The remainer is to be pushed to the North side of the pond area.
C. Bidnet Q3
1. Question: Can you provide the as-built pdf drawings of the existing splitter box structure?
2. Answer: As-Builts uploaded to Bidnet
D. Bidnet Q4
1. Question: Is TNorm testing required of the burden soil before disposing of it?
2. Answer: Yes, but no plans to remove it from the property or dispose of it.
E. Bidnet Q5
4/12/2024 00901-2 JVA 1000.5e
1. Question: The thrust block sizing in the chart on detail 5 of PD1.0 is based on 150 psi internal pressure of the pipe w/ hammer. The volume of concrete seems excessive.
Please confirm the volumes of concrete to be correct for the pipe bends on this project.
2. Answer: agreed. The thrust block can be eliminated as the flow fill detailed on Sheet
C3.2 satisfies the thrust restraint. An addendum will be issued reflecting this change.
2.2 EMAIL
A. Email Q1
1. Question: For the mud mat, is there a specific mix design and psi requirement?
2. Answer: Mudmat concrete shall be specified with a compressive strength of 3,000 psi at 28 days. Refer to Technical Specification 03300.2.4.D for mix design requirements.
B. Email Q2
1. Question: Is the reinforcing steel epoxy coated or black bar?
2. Answer: Reinforcement shall be uncoated bars, ASTM A615, Grade 60 bars. Refer to
Technical Specification 03210.2.1.A.
C. Email Q3
1. Question: Can you define the limits and elevation of the flowfill backfill on sheet C3.2.
2. Answer: Flowfill should extend a minimum of 24-inches beyond pipe and to bottom of excavation. Drawing C3.2 Updated via Addendum No. 1.
D. Email Q4
1. Question: Dewatering. What is the minimum CFS which needs to be diverted around the excavation during construction?
2. Answer: Stream flow data can be found on Colorado�s Department of Natural
Resources website (https://dwr.state.co.us/Tools/Stations). The monitoring station is named CHICAGO CREEK BLW DEVILS CANYON NR IDAHO SPRGS C
(CHIDEVCO). The contractors must determine an appropriate diversion during lower flows (late summer/fall)
E. Email Q5
1. Question: Are there any private existing wells near the new construction site that may be affected during construction dewatering?
2. Answer: Contractor encouraged to check Colorado�s Department of Natural Resources website to determine whether nearby wells may be affected during construction
F. Email Q6
1. Question: Sheet P0.0. What is the length of the existing 8� demo?
2. Answer: Demolition should extend through the area of work as required for the new construction. As-builts were provided for additional information.
G. Email Q7
1. Question: What type of 24� PVC is required for bypass and sluiceway? Specs have listed C900 DR18 and D3034.
2. Answer: C900 DR18. Section 2.3 will be deleted via Addendum No. 1
4/12/2024 00901-3 JVA 1000.5e
H. Email Q8
1. Question: Will the pressure testing be required on the 24� PVC pipe? If so, at what pressure?
2. Answer: Pressure testing is not required as listed in Section 02616.3.16
I. Email Q9
1. Question: Will pipe deflection testing be required?
2. Answer: Pipe deflection testing is specified in Section 02616.3.14.D
PART 3 PROJECT MANUAL
3.1 SECTION 02616 � SITE PIPING
A. DELETE SECTION 2.3 � MATERIALS:
1. Plugs and Caps: Use pipe plugs or caps provided by the pipe manufacturer and approved by the Engineer for pipe stub outs
2. Reinforcement:
a. Reinforcing Steel: ASTM A615 Grade 60
b. Welded Wire Fabric: ASTM A1064
3. Concrete: Refer to Division 3 specifications
a. Minimum compressive strength: 4000 psi at 28 days
b. Cement: ASTM C150, Portland Cement, Type II
c. Aggregates: ASTM C33, free of deleterious substances
4. Gaskets: ASTM C923
a. Mastic: FS SS-S-210A, "RAM-NEK" or accepted substitution
b. Rubber: Neoprene, 40+ 5 hardness when measured by ASTM D2240, Type A durometer
5. Water: Clean and free of deleterious substances
6. Grout:
a. Non-Shrink, Non-Metallic Grout: Factory premixed compound consisting of non-metallic aggregate, cement, water reducing and plasticizing agents, capable of developing minimum compressive strength of 4000 psi in one day and 8000 psi in
7 days
b. Epoxy Grout: Three Component Epoxy Resin System
i) Two liquid epoxy components
ii) One inert aggregate filtered component
iii) Each component furnished in separate package for mixing at job site
PART 4 DRAWINGS
4.1 SHEET C3.2
A. ADD NOTE flowfill backfill to extend 24-inches minimum beyond piping
4/12/2024 00901-4 JVA 1000.5e
4.2 SHEET P1.0
A. DELETE thrust block from Intake Screen Plan View
4.3 SHEET PD1.0
A. DELETE Concrete Thrust Block Detail (No. 5)
END OF SECTION
1. Bidnet Q1
2. Bidnet Q2
JVA, Inc. 1319 Spruce Street www.jvajva.com Boulder, CO 80302 303.444.1951
Boulder ● Fort Collins ● Winter Park Glenwood Springs ● Denver
AECOM
7595 Technology Way Suite 200, Denver, CO 80237 303.694.2770 www.aecom.com
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APRIL 2024
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APRIL 2024
JVA, Inc. 1319 Spruce Street www.jvajva.com Boulder, CO 80302 303.444.1951
Boulder ● Fort Collins ● Winter Park Glenwood Springs ● Denver
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APRIL 2024
JVA, Inc. 1319 Spruce Street www.jvajva.com Boulder, CO 80302 303.444.1951
Boulder ● Fort Collins ● Winter Park Glenwood Springs ● Denver
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| 1000.5e - 00901 - Addendum 1 |
| SECTION 00901 |
| Addendum no. 1 |
| END OF SECTION |
Bidnet Q&A Draft - Pictures
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