Morrisville Engineering, Design, and Construction Manual - July 2016

Section 3: Earthwork 3.3 Retaining Walls 3.2.6 Cut and Fill Slopes

Cut and Fill Slopes

3.2.6.

Cut and fill slopes should be no steeper than 4:1 (horizontal: vertical) unless additional stabilization techniques are proposed. Slopes steeper than 4:1 may be allowed with prior authorization. Slope stabilization calculations shall be provided to the Town Engineer for review and approval for any slope greater than 4:1. In no case shall slopes steeper than 2:1 be permitted. The developer shall be required to establish a permanent stand of vegetation on all slopes. All bare spots on public and private property shall be maintained and re-vegetated as necessary. Any areas that have not established a good stand of growth shall be re-vegetated until such vegetation is established. The Town may require a cash bond until the vegetation is deemed acceptable by the Town. Cut and fill slopes adjacent to Public Rights-of-way that directly impact public infrastructure may require permanent slope easement(s) to allow the Town to conduct repair and maintenance work.

3.3. RETAINING WALLS

General

3.3.1.

This section is intended to clarify requirements for the industry and promulgate uniform enforcement processes.

Applicability

3.3.2.

This section is intended to clarify the requirements in the Section 1807.2 of the North Carolina Building Code, as amended, and the Town. These requirements shall apply to all commercial construction that includes retaining walls and grades falling within the criteria described in Section 1807.2 of the current North Carolina Commercial Building Code. In addition, the Town may apply these requirements to any nonresidential, mixed-use, and residential projects where retaining walls impact public use or access areas, span across property lines, or are integral to the construction of a structure, or where these requirements are otherwise deemed necessary by the Town Engineer. Any retaining wall with 4 or more feet of exposed face height (finished grade to top of wall) or extending 5 or more feet from bottom of footing to the top of wall shall be designed by a registered Professional Engineer in the State of North Carolina. Construction of any retaining wall may not proceed until the Town has reviewed a complete application and issued a “released for construction” letter and stamped construction documents. This “release for construction” shall not constitute a review of the technical engineering as it is the Engineer of Record’s responsibility to ensure the calculations, plans, and specifications meet.

Submittal Requirements

3.3.3.

Plans for retaining walls subject to this section shall:

Be prepared by a Professional Engineer registered in the state of North Carolina;

Provide a standalone set of construction drawings with corresponding design calculations and specifications for the retaining wall system specific to the site; Provide the minimum required soil testing and quality assurance inspections that would be provided during earthwork and wall construction operations;

Provide top of wall and bottom of wall elevations on construction drawings; and

Include any additional information outlined in:

1.

Section 4.2.6 of this manual; and

January 2016

Morrisville, NC

Page 10

Engineering, Design, and Construction Manual