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Home My WebLink AboutSUB202100115 Correspondence 2021-10-22 (4)RKI%K 2100 East Cary Street Suite 309 Richmond, VA 23223 Phone 804.782.1903 Fax 804.782.2142 www.rkk.com Date: October 20, 2021 To: John Anderson, PE From: Amy Samberg, PE (RK&K) Cc: Malachi Mills, PE (RK&K) RE: Worrell Dr. — Road Plan SUB-2021-00115, Review #1 Engineering Comments (dated 07/26/2021) MEMORANDUM 1. Remove sheets C11.00, C11.01, C11.02 from the Road Plan, and include with WPO plan and application. Please submit WPO plan at earliest convenience. WPO plan approval is required concurrent with Road Plan approval. • Response: Sheet shall be removed from Road Plan Set. WPO plan set shall be submitted. 2. C2.00: Label Worrell Office Driveway, DrivewayJl, Small Drive 11. • Response: Sheet C2.00 shall be updated to show labels on proposed driveways. 3. Please remove 4th sheet of ROAD Plan (.PDF) if not relevant (it appears to be blank, or empty). • Response: 4th sheet is intended to be 'C3.00 —Erosion and Sediment Control Notes and Details, it did not appear in the setfor this submission and will be provided, as intended. 4. C4.00, Existing Conditions: Show and label Ex. storm pipe elements downstream of Ex. DI at Int. Martha Jefferson Drive and Worrell Drive. • Response: C4.00 and layout sheets shall be updated to provide information on existing storm system downstream of ex DI at Martha Jefferson/Worrell Dr. 5. Remove ESC elements from C5.00, 5.01, 5.02 (demolition elements may remain). ESC and SWM design elements are to be shown (reviewed and approved) with a WPO plan (application), but not a ROAD plan application. • Response: ESC symbols/elements shall be removed from C5X(series and Road Plan Set. 6. C6.00: a. Label Worrell Office Driveway, DrivewayJl, Small DriveJ1. Response: Labels shall be added to sheet C6.00. b. Label width of Worrell Drive at periodic intervals. • Response: Width along Worrell Drive shall be labeled at periodic intervals. c. Proposed R =112' is less than VDOT standard Min. R' horizontal curves, for typical design speeds. • Response: Worrell design shall be updated to show a min. of 155' to meet VDOT standard min. at the current design speed (25 MPH) (Per VDOT Geometric Standards for Urban Local Street Systems (GS-8). d. Provide VDOT/AASHTO* basis of design. For example: Road Design Manual, Appx. B(1). * AASHTO Guidelines for Geometric Design of Low -Volume Roads, 2019 ( https:Haashtojournal.org/2019/05/31/aashto-issues-second-edition-of-low-volume- roads- guidelines/ ) • Response: Design is based in the parameters of the VDOT Road Design Manual, Appendix Al, 'Geometric Design Standards for Urban Local Street System (GS- 8). e. Provide design speed. • Response: Design speed is 25 MPH, note shall be added to sheet C6.00 and sheet C7.00. f. Provide, show and label posted speed limit signs on layout plan view sheets, Worrell Drive. • Response: Posted speed limit signs shall be added on layout plan sheets along Worrell Dr. 7. C6.00: To the extent CL of revised Worrell Drive departs existing private street easement recorded at DB- PG 642-290, show and label revised private street easement. Provide easement plat, as needed. • Response: Revised private street easement shall be updated on sheet C6.00. Easement plat shall be provided. 8. C6.00, C6.01, C6.02: Please add Worrell Drive centerline stationing, every 100', with tick marks at more frequent intervals. • Response: Centerline stationing and ticks marks shall be updated as requested. 9. C7.00, C7.01, C7.02: • Similar to review item #5, above, please remove ESC symbols /elements from the road plan. Retain grading information. • Response: ESC symbols/elements shall be removed from C7.XX series and Road Plan Set. • Label new path width opposite Worrell Office Driveway. • Response: Path width shall be updated on sheet series C7.00 and C7.02. • Label traffic control signs. • Response: Traffic control signs shall be labeled on sheet C7.00. • LabelCG-12. • Response: CG-12 shall be labeled in sheet series C6.XX and C7.XX. 10. C7.00: a. Provide ADT basis of pavement design. • Response: ADT basis of pavement report shall provided with submission. b. Provide pavement design based on ADT: DR, DP. • Response: Pavement design based on ADT shall be provided, detail shall be added on sheet C6.01. c. Provide Worrell Drive pavement section depth/s for stone, sub -base and surface asphalt. Label Worrell Drive section (depths). • Response: Pavement section shall be provided based on ADT design and shall be added on sheet C6.01. 11. C7.01: a. With road plan, provide analysis of hydraulic effect of Worrell Drive storm discharge to pond upstream of the road. At this point, Worrell Drive is a pond embankment. If hydraulic effect is negligible, provide supporting hydraulic data that compares pre- /post developed 10-yr event flows not simply through structures proposed to discharge to the pond, but through the existing structure that connects upslope /downslope ponds, passing beneath Worrell Drive. • Response: Hydraulic data results show that the hydraulic effect is negligible from pre and post developed 10-yr flows. Results shall be placed in sheets C11.04-01.05. b. Show /label Ex. pipe structure (type, length, DIA) that connects ponds, that passes beneath Worrell Drive. • Response: 36" RCP that connects ponds beneath Worrell Drive description labels can be found on both ends of pipe. c. Please provide discrete (pond routing) analysis. • Response: Pond routing analysis shall be performed, and results will be placed in sheets C11.04-C11.05. d. Storm conveyance must discharge to a manmade network, natural receiving stream, or defined drainage channel. Revise discharge at 4-1 and 5-1 to discharge to a defined drainage channel (by extending pipe to a point that is a defined drainage channel, or natural receiving stream). • Response: Design shall be updated to show a level spreader to dissipate discharge at 4-1 and 5-1 outfall structures. 12. C7.02: a. Pipe table lists pipe slope, 3-1 to 3-2 as 0.5, while C9.00 lists slope as 0.47%. Pipe slope <0.50% should be revised to meet Albemarle Engineering Drainage Plan checklist for plan reviewers, Min. slope, =0.50% [ item 3, pg. 2; checklist /Attached]. • Response: Pipe slope shall be updated to meet Albemarle Eng. Drainage Plan checklist (using a min. of 0.55%). b. Label asphalt path. • Response: Asphalt path shall be labeled on sheet C7.02. c. Provide asphalt path cross-section. 0 Response: Asphalt path cross-section shall be provided. d. Revise outfall structure 3-2 to ensure discharge is to a manmade system, natural receivingstream, or defined drainage channel. • Response: Design shall be updated to show a level spreader to dissipate discharge at 3-1 outfall structure. 13. C8.00: a. Please show proposed vertical alignment in lower half profile, Sta. 4+25—10+48.34 (end project). • Response: Along section of Worrell Drive (4+35.25-10+48.34), existing grades are to be maintained and existing road widened in that section. b. Provide vertical curve at Sta. 2+61.19 to transition from 4.51%to 1.04% grade. Transition is abrupt, without VC. Smooth vertical curve is required to transition between grades. • Response: Vertical curve shall be added to smooth transition between grades. c. Recommend label points of intersection with intersecting driveways (Worrell Office Driveway, DrivewayJ1, for example). • Response: Intersection labels shall be added to profiles. 14. C8.01: Recommend Worrell Office Driveway Min. KSag of 15.00 (typical of pvt./public streets) for safe illumination of vertical sag curve after dark. • Response: Worrell Office Driveway shall be revised to have a min. KSag of 15.00. 15. C9.00: a. Revise proposed 0.47% storm line grade, 3-1 to 3-3 to 0.50%, Min. • Response: Piping shall be revised to be 0.55%. b. Immediately upstream of line 3-1 to 3-3 is a storm line at 0.50%. Three storm pipes are proposed at Min. pipe slope, 0.50%. Pipe installed at flatter slope (<0.50%), As -built, condition, requires Engineer confirm adequate self -scour velocity and capacity in As -built condition. Pipe < Min. pipe slope may need to be replaced (along with riser section/s) to ensure adequate fall, capacity, and self -scour velocity. Engineering recommends design slope 0.55% or greater, to allow leeway during construction. • Response: Storm pipes in design shall be updated to show 0.55%slope or greater. c. Storm profile Storm Sewer Ex DI to 1-2 indicates 18" DIA pipe/s feed into an existing storm structure with 15" DIA INV OUT. This is atypical; revise to ensure existing DI structure and existing pipe network for this storm pipe run are adequate to convey anticipated development runoff. I.E.: Examine /route existing storm pipe network downstream of Ex. DI that receives development runoff at Int. Martha Jefferson Drive and Worrell Drive. See existing condition at Ex. DI, C400. • Response: Design shall be revised to provide existing network downstream, and analysis shall be made to determine if 15" is adequate for design. 16. C11.03: Unless overlooked, provide spread (4 in. event) for DIs on Worrell Drive. 0 Response: Spread calcs have been updated. 17. If Worrell Drive, a private street, is to remain passable to thru-traffic during construction, provide narrative sequence that discusses maintenance of traffic (MOT), lane restrictions, barriers, flagging requirements, or any proposed limits on hours of construction activity (mill/pave, for example). Note: WPO Plan should indicate location of staging area/s (contractor vehicles, equipment, material storage, etc.). • Response: Maintenance of Traffic Plans shall be added to the plan set to provide required information (sheets C12.00-02.02). Staging area shall be added and can be in sheet C3.01.