HomeMy WebLinkAboutSUB202100115 Correspondence 2022-02-01 (3)RKI%K
2100 East Cary Street
Suite 309
Richmond, VA 23223
Phone 804.782.1903
Fax 804.782.2142
www.rkk.com
Date: January 21, 2022
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 #2
Engineering Comments (dated 12/9/2021)
6. C6.00:
MEMORANDUM
c. Proposed R =112' is less than VDOT standard Min. R' horizontal curves, for typical design
speeds. (Rev. 1) Persists. Applicant response (letter d. 10/20/21): '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)'.
Layout C6.01 appears to show CL radii of horizontal curvature < 155' (112', 125'; Sta.
9+50 and 6+25, respectively). Please clarify design intent.
• Response: Existing Road alignment along Worrell Drive from STA 4+25 to STA
10+48 is to be maintained as this portion is the section to just be widened, no
realignment is proposed.
7. C600: 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. (Rev. 1) Persists. Applicant: 'Revised private street easement
shall be updated on sheet C6.00. Easement plat shall be provided.'
• Response: The CAD files have been sent to the surveyor for processing. They will
provide the easement plat for review.
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. (Rev. 1) Partially addressed. As follow-up: Please
confirm that routing data shown on C11.05 indicate that the 36" RCP that connects the
ponds beneath Worrell Drive has adequate capacity to convey the 10-yr event, which
appears to route /model as Qpeak,10-yr=569.08cfs. Provide LD-229 storm design
computations for this existing 36" RCP pipe, that reflect modeled results.
• Response: Storm calculations have been added to 2yr and 10 yr tables on sheet
C11.03. The capacity and surface elevations remain the some within pre and
post conditions. Calculations on the pond capacity have also been added
through use of a HydroCAD model, which can be found on sheet C11.04 and
C11.05.
12. C7.02:
c. Provide asphalt path cross-section. (Rev. 1) May persist. As follow-up: perhaps
overlooked, please direct reviewer to sheet detail showing asphalt path cross-section.
• Response: Asphalt path cross-section has been added to sheet C7.02
15. C9.00:
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 forthis 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
16. C11.03:
and Worrell Drive. See existing condition at Ex. DI, C400. (Rev. 1) May persist.
Applicant: 'Design shall be revised to provide existing network downstream, and analysis
shall be made to determine if 15" is adequate for design' As follow-up: Please provide
(analysis) findings of system adequacy of proposed v. existing storm pipe.
• Response: Storm calculations have been revised and existing downstream
system is adequate for proposed 15" storm sewer pipe connection, which are
shown on sheet C11.03.
Unless overlooked, provide spread (4 in. event) for Dls on Worrell Drive. (Rev. 1)
Partially addressed. Applicant: 'Spread calcs have been updated' As follow-up: It
appears that C11.03 has been removed from the road plan set. Please restore this sheet
to the road plan so updated spread calcs may be checked.
• Response: Sheet C11.03 will be included in this submission.
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.). (Rev. 1)
Addressed. As follow-up: Engineering recommends Note/s to contractor, barriers, labels,
etc. on the road plan to control and limit pedestrian access to areas closed to vehicles
during any phase of construction. If portions of roads are closed for construction,
pedestrian intersections with roads under construction should likewise be temporarily
closed, with adequate barrier protection and public notices that help ensure pedestrian
safety.
• Response: We have added notes on the MOT plan sheets temporarily closing
pedestrian intersections/path segments accordingly. We have provided
additional notes in the Sequence of Construction for the Contractor to add safety
fence as necessary to ensure pedestrian safety during the different phases. We
have also specified in the Maintenance of Traffic notes that when sidewalks /
pedestrian path closures are implemented, the paths shall be closed using type 3
barricades and the sidewalk closed sign in accordance with the latest revision of
the 1011 VWAPM.