Morrisville Engineering, Design, and Construction Manual - July 2016

Section 3: Earthwork 3.3 Retaining Walls 3.3.4 Design and Construction Standards

2. Part 4.5.20, Retaining Wall Submittal Checklist, of the Administrative Manual.

Design and Construction Standards

3.3.4.

All structural elements of the retaining wall integral to the function of the system, which include, but are not limited to, footings, tie backs, drainage, etc., must be shown on the plans and encompassed within a permanent private easement for maintenance, unless specifically agreed to be Public by the Town. No structural component of any retaining wall shall be located within a public right-of-way or access easement, riparian, streetyard, or perimeter buffer, or utility easement. All plans must clearly show any proposed retaining wall and the corresponding tie-back and/or grid system to ensure that no encroachments are being proposed. Railings, guardrails, or traffic barriers shall be required along walls with vertical drops greater than 2.5 feet that are located within 10 feet from the edge of public rights-of-way or access easements, private access easements, parking lots, sidewalks, bicycle travelways, parks, or playgrounds, or as required by the Town. See Appendix C: Standard Details & Notes. Fencing or safety rails are required where retaining walls or storm drainage headwalls have vertical drops of 4 feet or more. See Appendix C: Standard Details & Notes.

Refer to the North Carolina Building Code and NCDOT for additional requirements.

Construction Inspection and Testing

3.3.5.

The developer shall obtain inspection and testing services, including independent laboratories, to provide quality assurance and testing services throughout the construction of all retaining walls. Testing and inspections services shall only be performed by qualified and experienced technicians and Professional Geotechnical and/or Structural Engineers Registered in the State of North Carolina. At a minimum, quality assurance testing shall include foundation soil inspection, soil and backfill testing, verification of design parameters, and observation of construction for general compliance with design drawings and specifications.

Post Construction Certification

3.3.6.

On completion of retaining wall(s) construction, a licensed Professional Engineer in the State of North Carolina is required to submit to the Town a certification report. This report shall include field inspection reports and test results, and shall certify that retaining walls are constructed per the engineered drawings and in compliance with Local, Federal, and State codes. Certificates of Compliance/Occupancy can only be issued after receipt and review of the engineer’s certification.

Morrisville, NC

July 2016 Page 11

Engineering, Design, and Construction Manual