City of Frisco Engineering Standards

Engineering Standards
C. All valves, fittings and changes in elevation shall have concrete thrust blocks and restrained joints
installed.
D. Thrust blocking shall be Class “PA” concrete per NCTCOG Item 702.2.4.3 and be able to
withstand a minimum 200 psi test pressure with a minimum safety factor of 1.5 without
exceeding the soil bearing capacity.
E. Restrained joints lengths shall be calculated to withstand a minimum 200 psi test pressure with a
minimum factor of safety of 2.0.
F. The following technical references are available for calculating thrust restraint systems:
1. AWWA Manual M9: Concrete Pressure Pipe by AWWA, Latest Edition.
2. AWWA Manual M11: Steel Pipe – A Guide for Design and Installation by AWWA, Latest
Edition.
3. AWWA Manual M23: PVC Pipe – Design and Installation by AWWA, Latest Edition.
4. Thrust Restraint for Ductile Iron Pipe by Ductile Iron Pipe Research Association (DIPRA),
2006, or Latest Edition.
5. Thrust Blocking, National Fire Protection Association Standard 24, Standard for the
Installation of Private Fire Service Mains and Their Appurtenances, 2007 Edition
5.6 Pavement Cut and Repair
A. Water and wastewater and reclaimed water main improvements shall be designed to minimize the
impact to existing pavement, where feasible.
B. No pavement shall be cut unless approved in writing by the Director of Engineering Services.
Existing pavement cut, excavation and repair shall be in accordance with NCTCOG Item 402 and
NCTCOG Standard Drawings 3070A through 3070D.
C. Full panel concrete pavement replacement will be required if pavement must be cut.
5.7 Trenchless Construction
A. Launching and receiving pits for trenchless construction shall be a minimum of 5’ from the edge
of pavement.
B. The location, size and depth of the launching and receiving pits for trenchless construction shall
be evaluated during construction plan review.
C. Approved Methods
1. Horizontal Boring - Horizontal boring shall require a steel casing pipe with a minimum yield
strength of 35,000 psi and minimum wall thickness of (1/4”). Actual wall thickness shall be
designed based on a highway loading of HL-20, a maximum deflection of 5% and a
minimum factor of safety of 2.0.
2. Pipe Jacking - Pipe shall be designed to withstand all jacking forces with a factor of safety of
2.0 during construction.
Section 5 – Water & Wastewater Design Requirements May 2012 Page 5-18