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Question
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Date:
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9/22/2020 9:33:24 AM
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Based on the number of quantity and plan changes to be made after the letting would the owner consider extending the bid date one week to allow these changes to be incorporated into the bid documents making them available to all bidders and not just the awarded bidder?
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Answer
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Question
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Date:
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9/21/2020 3:34:24 PM
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Could the design team please provide performance criteria for the Densified Aggregate Pier scope? Is the intent of the Densified Aggregate piers to improve global slope stability under Abutment A to a certain required factor of safety? To control settlements to the limits indicated on Plan 299-88? or both? We noted that the Geotechnical Report by ECS Mid-Atlantic, LLC dated 7/20/17 does not discuss the use of Densified Aggregate Piers for either.
The revised Special Provision for Densified Aggregate Piers dated 9/15/20 Section I requires that the piers themselves have an internal friction angle of 45 degrees and then seems to indicate that the composite friction angle of the reinforced soil mass also requires a friction angle of 45 degrees (see below). Accounting for varying construction techniques it is typical to see DAP’s with internal friction angles varying between 40-50 degrees. This would imply an area ratio of 100% which would be nigh impossible to build. Please provide the required composite friction angle of the DAP reinforced soil and the design friction angle of the in-situ soils to be reinforced at Borings 17BH-05 and 17BH-04 so that the DAP Installer’s Engineer can verify the required ground improvement techniques.
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Answer
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Date:
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9/22/2020 4:48:09 PM
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The DAPs had been designed by the Engineer to reduce settlement and improve global stability. DAPs Contractor shall construct the DAPS in accordance with the Special Provision for Densified Aggregate Piers and Plans.
Based on Section I fourth paragraph of the Revised Special Provision for Densified Aggregate Piers (September 15, 2020), the 45 degrees internal friction angle refers to the densified aggregate pier (DAP) itself, not the composite friction angle of DAP improved soil mass.
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Question
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Date:
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9/21/2020 3:33:22 PM
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Could the design team please provide performance criteria for the Densified Aggregate Pier scope? Is the intent of the Densified Aggregate piers to improve global slope stability under Abutment A to a certain required factor of safety? To control settlements to the limits indicated on Plan 299-88? or both? We noted that the Geotechnical Report by ECS Mid-Atlantic, LLC dated 7/20/17 does not discuss the use of Densified Aggregate Piers for either.
The revised Special Provision for Densified Aggregate Piers dated 9/15/20 Section I requires that the piers themselves have an internal friction angle of 45 degrees and then seems to indicate that the composite friction angle of the reinforced soil mass also requires a friction angle of 45 degrees. Accounting for varying construction techniques it is typical to see DAP’s with internal friction angles varying between 40-50 degrees. This would imply an area ratio of 100% which would be nigh impossible to build. Please provide the required composite friction angle of the DAP reinforced soil and the design friction angle of the in-situ soils to be reinforced at Borings 17BH-05 and 17BH-04 so that the DAP Installer’s Engineer can verify the required ground improvement techniques.
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Answer
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Date:
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9/22/2020 4:48:20 PM
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The DAPs had been designed by the Engineer to reduce settlement and improve global stability. DAPs Contractor shall construct the DAPS in accordance with the Special Provision for Densified Aggregate Piers and Plans.
Based on Section I fourth paragraph of the Revised Special Provision for Densified Aggregate Piers (September 15, 2020), the 45 degrees internal friction angle refers to the densified aggregate pier (DAP) itself, not the composite friction angle of DAP improved soil mass.
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Question
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Date:
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9/18/2020 12:56:24 PM
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Will we be required to pin or bolt-down all of the MB-10A and MB-11A?
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Answer
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Date:
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9/18/2020 3:10:56 PM
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Barriers on bridge decks will be required to be pinned; otherwise barrier anchorage is dependent on the criteria expressed in Appendix A of the workzone protection manual and the applicable Virginia Road and Bridge Standards.
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Question
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Date:
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9/18/2020 11:51:58 AM
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The typical section 2A(5) and cross sections for Glenwood drive indicates the existing road will be built up with asphalt to the proposed grades. The road plans Sheet 4 & 4D indicates roadway demolition of the existing pavement If roadway demolition is required then temporary access will likely need to be maintained on stone. What is the departments intent?
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Answer
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Date:
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9/21/2020 1:45:00 PM
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The pattern file referenced into sheets 4 and 4D will be updated to agree with typical section sheet 2A(5) and cross sections. The only roadway demolition along Glenwood Drive is from stations 40+00 to 40+27. No temporary access will be needed.
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Question
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Date:
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9/18/2020 10:08:21 AM
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There seems to be a conflict in the proposed grade between the plans at the Soil Nail Wall in front of Abutment B. The finished grade in front of the wall is approximately 209+/- under the bridge as shown on bridge plan sheet 62 and road plan sheet 2I. However, as the ends of the wall tie back into existing, the wall plan shows the same grade 209 to the end of the wall as the top of the wall slopes down from 224.50 to 209, while the road plan shows the grade sloping up to match the existing grade of 230. Can you please clarify the correct proposed grade(s) for construction along I-95 since this is a difference of roughly 20' in elevation?
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Answer
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Date:
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9/21/2020 1:45:32 PM
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The finished grade of the soil nail wall shown on the bridge plan sheet 62 is correct. The proposed contours on roadway sheet 2i will be revised after the letting.
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Question
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Date:
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9/18/2020 9:20:56 AM
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The road plans state on the coversheet that this project is to be constructed in accordance with the department's 2016 road and bridge specifications, while the bridge plans state it should be built in accordance with the 2020 specifications. This has the potential to generate confusion during construction. Can the entire project be built under one set of specifications?
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Answer
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Date:
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9/21/2020 1:43:45 PM
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This project will be constructed in accordance with the 2016 Road and Bridge Specifications. Please refer to page 1 of the contract.
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Question
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Date:
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9/18/2020 9:17:41 AM
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Plan Sheet 2G notes 406LF of MB-7E Median Barrier on Sheet 4. No MB-7E is shown on Sheet 4. Where is this Median Barrier located?
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Answer
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Date:
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9/21/2020 1:44:23 PM
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The quantity for the MB-7E median barrier should not have been shown on sheet 2G. The quantity was already included in the bridge plans for the pier protection barrier under the bridge (see bridge plan sheet 2). Revised plans showing this quantity deleted will be available after the letting.
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Question
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Date:
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9/18/2020 9:17:40 AM
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Plan Sheet 2G notes 406LF of MB-7E Median Barrier on Sheet 4. No MB-7E is shown on Sheet 4. Where is this Median Barrier located?
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Answer
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Date:
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9/21/2020 1:45:48 PM
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The quantity for the MB-7E median barrier should not have been shown on sheet 2G. The quantity was already included in the bridge plans for the pier protection barrier under the bridge (see bridge plan sheet 2). Revised plans showing this quantity deleted will be available after the letting.
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Question
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Date:
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9/17/2020 4:26:51 PM
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What is the design and/or test load in kips for a single 24" densified aggregate pier?
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Answer
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Date:
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9/22/2020 8:19:41 AM
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Per SPECIAL PROVISION FOR DENSIFIED AGGREGATE PIERS, Section III LOAD TESTS, third paragraph, "the design stress shall be considered as 125% of the overburden stress at the maximum fill height section. The unit weight of fill shall be considered to be 125 pcf.". Maximum fill height section can be calculated from the difference between the roadway elevation and top of densified aggregate piers.
Test stress calculation shall follow SPECIAL PROVISION FOR DENSIFIED AGGREGATE PIERS, Section III LOAD TESTS, second paragraph, "Testing shall be performed based on the highest design pier stress and the test shall be run to a stress level of 150% of this design stress". Design load and test load in kips can be calculated based on densified aggregate pier cross section area and design stress and test stress, respectively.
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Question
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Date:
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9/17/2020 4:25:12 PM
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Due to the recent Addenda with significant specification changes, will a bid due date extension of one week be considered?
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Answer
1 previous answer(s)
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Date:
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9/18/2020 9:57:20 AM
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A delay will not be issued as the specification changes referenced were minor in nature. They were done to remove the qualification requirements associated with the referenced specifications.
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Question
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Date:
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9/17/2020 4:45:37 PM
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We would like to second that request for an extension due to the most recent revision. The key components that were revised have a limited number companies capable and qualified to complete the work. They have expressed a great need for a time extension to fully evaluate the impacts to their scope and pricing.
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Answer
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Date:
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Question
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Date:
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9/17/2020 12:53:44 PM
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Page 58 of the bridge plans shows Settlement Plates behind Abutment A. How are these Settlement Plates paid for?
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Answer
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Date:
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9/18/2020 12:25:33 PM
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All costs associated with the settlement plates and monitoring work shall be incidental to the bid price for the MSE Wall. No separate payment will be made.
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