Morrisville UDO Administrative Manual, August 1, 2018 version

Part 2. Application Review Procedures 2.4 Additional Application Procedures

 The 2012 North Carolina Building Code, Section 1807.2.5 includes requirements for the design and construction of retaining walls associated with Commercial Development. Specifically: Retaining systems providing a cumulative vertical relief greater than 5 feet (1524 mm) in height within a horizontal separation distance of 50 feet (15 m) or less, including retaining walls or mechanically stabilized earth walls, shall be designed under the responsible charge of a registered design professional. Retaining systems shall meet the requirements of Section 1610. Testing and inspection reports shall comply with Section 1704.1.2 and shall verify:

 Foundation support system is adequate for the intended site conditions;

 Measurement of the quality of construction materials for conformance with specifications;

 Determination of similarity of actual soil conditions to those anticipated in design; and

 Examination of backfill materials and any drainage systems for compliance with plans and specifications.

Retaining Wall Review Procedure

B.

1. Design and Submittal Requirements

 The submittal of a standalone set of construction plans with corresponding design calculations and specifications for the retaining wall system, prepared and sealed by a Professional Engineer registered in the state of North Carolina.  This submittal must note the minimum required soil testing and quality assurance inspections that would be provided during earthwork and wall construction operations.  No structural component of any retaining wall can be located within a right-of-way, perimeter or streetyard buffer, or easement.  Tie backs must be shown on the plans. Railings, guardrails, traffic barriers, etc., must be installed along the edges of retaining wall structures as identified on the approved construction plans and the corresponding retaining wall plans. 2. Construction Requirements

Retaining Walls

Application Submittal and Acceptance

Staff Review and Comments

Application Revisions

Follow-Up Staff Review

Post Construction Documentation

 Construction of retaining walls may proceed only after the Town has

reviewed and issued a Released for Construction letter. This release for construction does not represent a full technical review of the submittal, and it is the Engineer of Record’s responsibility to ensure all design parameters and construction techniques specified within the documents are in accordance with Federal, State, and Local code requirements and industry standards to protect the health, safety, and welfare of the public.  The owner shall be required to engage inspection and testing services, including independent laboratories, to provide quality assurance and testing services throughout the construction of all retaining walls.  Testing and inspection services shall only be performed by qualified and experienced technicians and engineers. At a minimum, quality assurance testing must include foundation soil inspection, soil and backfill testing, verification of design parameters, and observation of construction for general compliance with design drawings and specifications.

3. Post Construction

 On completion of retaining wall(s) construction, the Engineers will be required to submit a certification report along with field inspection reports and test results to the Town, certifying that

Morrisville, NC

August 1, 2018

Administrative Manual

Page 2-17