QnA 6982AF24B000008 04-16-2024.pdf

Questions and Answers during Advertisement for CO FLAP CR300(1) Browns Canyon Access Road

6982AF24B000008

March 20, 2024

Questions Answers 1 Is Blasting anticipated on this project? Yes, blasting is anticipated. For more information, refer to

SCR 108, 156, 205, 206,

Construction Plans: B3, C1, D1 & cross sections Geotech Report

Pre-Bid Meeting April 4, 2024

2 Is there any chance we could submit the original bid online? No, submit a printed copy of your bid with original bid bonds according to Sheet A-i of the Invitation for bid.

3 The plans says the swell factor is 160%, is that correct? What method is used to measure area and quantity of rock excavation?

Correct, the swell factor for measuring rock excavation is 160% based on a loose placement. Refer to the grading summary on Plan Sheet B3.

Prismoidal surface to surface volume was used for calculations.

4 Is there storage for materials on site? Refer to Special Contract Requirements Subsection 105.04 in the IFB.

Storage areas are to be secured by the contractor.

5 Where are the rock bolts intended to be installed? The rock bolt placement is at direction of the CO, so it will be based on field conditions as exposed during rock excavation during construction.

They are included in the contract to stabilize rocks that are unstable but cannot be removed by traditional slope scaling activities. Refer to Sheet B1 in the plans.

6 If the road closure is after September 2nd, how is the weather during that time?

Weather during this time of season was vetted with the partners. Weather will be getting colder, and some snow may happen. The project is south facing, so if there is any snowfall, it should melt quickly. Refer to FP-14 Subsection 108.03 for weather delay information.

7 Are there predetermined staging areas and source of water that's also 105?

There are no designated water sources. The contractor is responsible for sourcing water. Refer to Section 105.04 of the FP-14 and SCR’s.

8 Please confirm the seeding window. The seeding window is 10/15/24 to 11/15/24. Refer to Subsection 625.11 of the SCR’s.

9 When is the anticipated notice to proceed? Notice to Proceed will be given approximately 2 weeks after award of the contract (award will be in accordance with the Basis for award on Sheet A-4 of the IFB, and NTP is dependant upon contractor returning required acceptable documents in a timely fashion). Contract award is anticipated mid to late May. Ground disturbing activities will commence in accordance with SCR Subsection 108.01.

10 The disposal area for the excavated materials, how far is that exactly from the site of blasting?

It is approximately 8 miles.

11 What is the construction duration from September? Ground disturbing activities will start after September 2, 2024, and the contract completion date is December 11, 2024. Refer to Subsection 108.01 of the SCR’s.

12 For the river monitoring, I guess I'm not familiar with that river.

How heavy is the river traffic and I presume we'll just have to wait for an open window for blasting opportunities or will there be a way to stop river traffic?

Refer to SCR’s Subsection 156.04 for the Public Information Officer, river monitor, and the duties required. The Public Information Officer will provide a blasting schedule to the county and partner, and they will help notify the public and rafting companies of closures related to the blasting activities. There will also be a river monitor 1500 feet upriver to waive any public river users to the shore.

13 So, there will be some limitation with the commercial companies in regards to rafting at times of blasting?

Yes, there will be.

14 Is there possibility that that the invitation for bid will get extended past April 16th.

Refer to Amendment A001.

Questions received April 5, 2024

Questions received April 16, 2024

18 Section 109.5 is referenced in the specs for payment items but is not included in the job specifications. Please advise.

Our project Special Contract Requirements (SCRs) supplements the Standard Specifications for Construction of Roads and Bridges on Federal Highway Projects (FP-14). Regarding the questions, see FP-14 Section

109.05 for more details.

19 1. Section 4.1.4 Blasting of the Geotech Report suggests presplit should be used as the method of blasting and that "appropriate controlled blasting techniques should be employed." Spec section 205.02 B gives two definitions for controlled blasting techniques: presplit and cushion blasting. Further on, section 205.07 under test blasting, paragraph 2 starts with "Begin the test blasts with presplit..." It appears the blasting contractor is being directed to use presplit/cushion blasting drilling methods to facilitate this project.

However, Section 205.09 (b), Paragraph 2 states " use controlled blasting to form the final cut face on rock cuts where the staked slope ratio is 1-1/3V:1H or steeper and the slope height is more than 10 feet above the ditch grade. Therefore, blasting is only required from approximate station 18+00 to approximate station 20+75. In looking at the cross sections for those stations, final face design is 1.5:1, 1:1, 2:1, 1.75:1, 1.83:1 respectively. None of these slopes are steep enough to successfully drill the type of hole that is required for either Presplit or Cushion blasting techniques.

Other methods need to be employed. Is presplit or cushion blasting required, or can we employ other options to reach final face?

Section 205.09 allows for other approved blasting techniques. The goal is to produce a natural appearing final excavation free from drill holes (half-casts) and equipment scars.

15 Is there any staking currently on site? No 16 Is the top of the cut currently staked on site? No 17 Can you show the cut line on the photos from sheet D1 in the drawings?

No, the photos are to provide visual context of the existing material to be excavated.

20 It will be difficult to meet the 30-day requirement for blasting. Is this timeline flexible?

Section 108.01(c) provides 4 weeks, please bid in accordance with the plans and specifications.

21 Will the road be shut down to all access after September 8th? Contractors can close the road according to Section 108 and 156.

22 Are blasting mats mandated? Yes. The size, type and placement of blasting mats will depend on the contractor’s methods. The reason for mandating is to prevent rock from entering the Arkansas River.

23 Can the blasting contractor use the wide spot in the road at the end of the project for staging? If access is shut down, could the blasting contractor use this area for explosive magazine storage area? If not, please advise on a storage location.

a. Staging areas are to be Contractor located, see Section 105.04

b. Blasting activities, see Section 203.05 & 205.08,

i. Coordinate with the CO and haul any excess material generated from the excavation on the project to the County Staging Yard (613 Gregg Dr., Buena Vista, CO 81211),

ii. Remove the muck pile from the blast area as soon as reasonably possible, within same work shift. Remove all waste materials to an approved staging area.

iii. Manage the interaction of blasted rock piles and stormwater to prevent contamination of groundwater, spring water, and surface water.

iv. Do not use blasted material for embankment.

c. Storage Location, Contractor located, see Section

105.04. Recommend requesting the County for staging and

storage & keeping locations within County ROW.

24 How many days altogether do you estimate a PIM will be needed?

Public Information Management (PIM) timeline is determined by Contractor means and methods. See Section 156.04.

25 What is the time frame/dates for rockfall work to be done? Is the blasting work critical path?

Refer to Section 155 of the SCR’s and FP-14 for construction schedule. Excavation, which includes blasting, is the critical path. Rockfall work is assumed to follow blasting to clean up or secure any loose or unstable blocks remaining on the slope. Safety scaling is incidental to rock excavation and is to be performed as necessary to ensure safety of work crews and the public.

26 What are the work conditions for traffic control like? Is the road shut down or do we need to allow for tourists passing by?

See Section 156 of the SCR’s for how road must be open to traveling public.

27 Are you looking at erecting some kind of barrier up against the highwall to protect existing road?

Contractor to blast according to the approved site-specific blasting plan. Use blasting mats, rockfall containment systems, and other protective devices to prevent damage to surrounding features. See Section 205 of the SCR’s.

28 Can I assume the 5320 CY of roadway excavation is for the blasting area? Or is there another area for roadway excavation?

5320 cubic yards includes blasting & roadway excavation.