17716M M
® M M
152
ORDINANCE NO. 17.716
AN ORDINANCE AMENDING CHAPTER 30 OF THE CODE
OF ORDINANCES OF THE CITY OF LITTLE ROCK,
ARKANSAS, PROVIDING FOR CERTAIN TECHNICAL
AND PROCEDURAL REVISIONS.
BE IT ORDAINED BY THE BOARD OF DIRECTORS OF THE CITY OF LITTLE ROCK,
ARKANSAS:
SECTION 1. That Chapter 30 of the Code of Ordinances be amended as follows:
Subsection a. That Chapter 30, Section 30 -167. Pipe., be amended as follows:
Drainage pipe used in construction of culverts and storm sewers shall be
of the types of material as specified in Section 13, Pipe Culverts and
Storm Drainage Piping, of the City of Little Rock Technical
Specifications, Latest Edition.
Subsection b. That Chapter 30, Section 30 -174. Pipe Culverts and Storm
Sewers., be amended as follows:
The installation of culverts and storm sewer shall be in accordance with
Section 13, Pipe Culverts and Storm Drainage Piping, of the City of
Little Rock Technical Specifications, Latest Edition.
SECTION 2. That Chapter 30 of the Code of Ordinances be amended to add Section 30 -181
entitled "Amendments" as follows:
Sec. 30 -181. Amendments.
For the purpose of providing for the public health, safety and general welfare,
the Board of Directors may amend the provisions of this chapter. The City
department designated by the City Manager has the responsibility for updating
on a continuing basis the City of Little Rock Technical Specifications for
Public Works and Facilities Improvements.
SECTION 3. This ORDINANCE shall take effect thirty (30) days from and after its passage.
PASSED: April 21, 1998
ATTEST: APPROVED:
City Clerk Robbie Hancock Mayor UM Dailey
SECTION 13 - PIPE CULVERTS AND STORM DRAINAGE PIG g
13.01 Description
(a) This section covers all types of storm drainage pipe at the locations shown on the Plans or
as described by the Director of Public Works or designee. The use of alternate pipe types
is only permitted when specified as an approved alternate on the plans and /or bid
documents.
(b) All work shall be in accordance with the details shown on the Plans, or as directed by the
Director of Public Works or designee and with the following Specifications.
(c) Drainage pipe installations which are located in or cross under public streets shall be
reinforced concrete pipe as noted below in SECTION 13.03(a) for 54 inch diameter pipe
and below or shall be either SECTION 13.03 ( b ),( c ) , or ( d ) as noted below for various
types of Polymer Coated Steel Pipes. Those installations larger than 54 inch diameter pipe
shall be as approved by the Engineer and may include other approved materials as listed in
SECTION 13.03. All approved materials may be considered for drainage applications
which require smaller than 15 inch diameter pipe.
13.02 Standard Specifications
Materials and installation shall be in accordance with SECTION 606 - PIPE CULVERTS of the
Arkansas State Highway and Transportation Department Standard Specifications, except as
modified or augmented herein.
13.03 Materials
(a) Reinforced Concrete Pipe: All reinforced concrete pipe shall be Class III or higher,
unless otherwise noted on the Plans, with bell and spigot or tongue and groove joints and
conform to the requirements of the following latest editions of ASTM and AASHTO
Standards:
(1) AASHTO M 170 or ASTM C 76 - Circular pipe, minimum wall thickness `6'
(2) AASHTO M 206 or ASTM C 506 - Arch shaped pipe
(3) AASHTO M85 or ASTM C 14 - Horizontal Elliptical pipe (Major axis horizontal)
(4) AASHTO M 207 or ASTM C 507 - Vertical Elliptical pipe (Major axis vertical)
(5) AASHTO T 280 - Testing
The class of pipe and date manufactured shall be marked on each joint of pipe section.
Pipe shall be at least 10 days old before it is delivered to the project site.
Joints shall be sealed with compression type pre- formed rubber gaskets or bitumen /butyl
rubber plastic gaskets as indicated on Plans.
(b) Polymer Pre- coated Galvanized Corrugated Steel Pipe: The manufacture and
furnishing of galvanized corrugated steel pipe shall conform to AASHTO M 36 or ASTM
A 760. The galvanized corrugated steel pipe shall be coated inside and out with a
protective polymer coating conforming to AASHTO M 246 or ASTM A 742. The
polymer coating shall be a minimum of 10 mils thick. The polymer shall be composed of
polyethylene and acrylic acid copolymer, labeled TRENCHCOAT protective film, or
approved equal. The pipe shall have the TRENCHCOAT label, or approved equal, on the
outside of the pipe. Pipe gauge and corrugation requirements shall be indicated on the
® 0 1542
Plans. Paved inverts are required in closed systems if the slope exceeds 2.0 percent and in
open systems if the slope exceeds 1.5 percent or if severe abrasion is anticipated.
(c) Smooth Interior Polymer Pre- coated Galvanized Corrugated Steel Pipe: Same
specification as for 13.03 (b). To be used for increased hydraulic performance (Manning's
n= 0.012) or as indicated on Plans.
(d) Polymer Pre- coated Spiral Rib Metal Pipe Type 1R: To be used for increased hydraulic
performance (Manning's n= 0.012) or as indicated on Plans. The manufacture and
furnishing of spiral rib metal pipe shall conform to ASTM A 760.The spiral rib metal pipe
shall be polymer coated as specified in SECTION 13.03(6). Paved inverts are required in
closed systems if the slope exceeds 2.0 percent and in open systems if the slope exceeds
1.5 percent or if severe abrasion is anticipated. Acceptable manufacturer: Contech, Inc.,
"Ultra Flo" or approved equal.
(e) Smooth Interior Corrugated High Density Polyethylene Pipe (CPP): The manufacture
and furnishing of polyethylene pipe shall conform to AASHTO M 294 Type S (sizes
12inches- 36inches), latest edition; MP6 -95 Type D or S (sizes 42 and 48 inches), or MPX-
97(sizes 54 and 60 inches). Couplings and fittings supplied or recommended by the pipe
manufacturer shall be used. Factory installed bell and spigot joints with O -ring gaskets
meeting ASTM F 477 are required. Acceptable manufacturers: ADS, Inc., Hancor, Inc., or
approved equal.
(f) Large Diameter Closed Profile Polyvinyl Chloride (PVC) Pipe: The manufacture and
furnishing of pipe and fittings shall conform to ASTM F 794 and Uni -Bell UNI -B -9. Pipe
must be installed in accordance with pipe manufacturer's guidelines. Acceptable
manufacturers: Carton, Inc., "Vylon, H.C. ", or approved equal.
(g) Smooth Interior, Open Profile, Polyvinyl Chloride (PVC) Pipe (to 36 "diam.): The
manufacture and furnishing of pipe and fittings shall conform to AASHTO M 304. Pipe
must be installed in accordance with pipe manufacturer's guidelines. Acceptable
manufacturer: Contech, Inc., "A- 2000 ", Extrusion Technologies, Inc., "Ultra- Rib ", or
approved equal.
13.04 Jointing of Pipe
Jointing of all pipes shall be in accordance with SECTION 606 - PIPE CULVERTS of the
Arkansas State Highway and Transportation Department Standard Specifications and in
accordance with pipe manufacturer's guidelines.
13.05 Testin
Testing shall be in accordance with Paragraph 7, INSPECTION AND TESTING OF
MATERIALS, General Conditions of these Specifications. The Contractor is responsible for
providing density testing for every third compacted lift with 8 inch maximum (one test per two
feet of backfill). Test locations shall be spaced no further than every 100 feet of pipe, one per
street crossing, or as required by the engineer of record or the Public Works Department. Refer to
section 12.05 for density requirements. Failure to provide adequate density testing of backfill will
require removal of the backfill and recompaction with certified testing. The Public Works
Department reserves the right to require Mandrell tests on plastic drainage pipe to determine if
there is excessive deflection (greater than 7.5 %) or video camera the inside of all pipe types at the
0 0 155
sole cost of the contractor. Drainage pipe will be required to be removed and replaced if there is
excessive deflection.
13.06 Trenching and Backfill
Trenching and backfill shall be in accordance with applicable requirements of SECTION 12 -
UNCLASSIFIED EXCAVATION FOR STRUCTURES, except as augmented herein.
(a) Where unsuitable material is encountered, excavation shall continue until a firm material
is reached and the over - excavation filled to grade with a special bedding material as
covered in Section 20.
(b) Where flexible drainage pipe is used special trenching, bedding and backfill requirements
apply. The following are required minimum trench widths, minimum cover, and
maximum cover for the installation of flexible drainage pipe under traffic areas:
DIAMETER
(INCHES)
TRENCH WIDTH
(INCHES)
MINIMUM COVER
(INCHES)
MAXIMUM COVER
(FEET)
12
32
12
30
15*
36
12
30
18*
40
12
30
24*
50
12
30
30*
60
12
30
36*
66
12
30
42*
71
12
30
48*
77
12
30
54*
84
12
30
60
90
12
1 30
*Restricted to concrete pipe or polymer coated steel pipes under City streets.
Trench width must be wide enough to accommodate compaction equipment.
Minimum Cover is from top of pipe to top of subgrade (except where approved for
concrete pavement and driveways).
When parallel pipes are installed a minimum of 12 inches is required between each pipe in
addition to the trench widths given in the table above.
(c) Bedding for flexible drainage pipe requires a minimum of 4 inches of granular material
such as Class 7 and 8 material. If bottom of trench is rock or unyielding material 6 inches
of bedding is required. Bedding must be shaped to conform to the shape of pipe including
recesses for bell ends.
(d) Backfill for flexible drainage pipe shall be granular material such as Class 7 and 8
material. Backfill shall be placed and mechanically compacted to a minimum of 12 inches
above the pipe in accordance with Section 12.05. Special care should be taken so not to
damage the pipe.
(e) Backfill for all drainage pipe installed under traffic areas shall be granular material such
as Class 7 and 8 material. Backfill shall be placed and mechanically compacted up to the top
of subgrade in accordance with Section 12.05. Low strength concrete "flowable" backfill may
be used as an alternate backfill in areas of drainage structures and other utilities.
(f) In non - traffic areas, trench width and backfill material may be varied by the Design Engineer
for a more economical design if approved by the Director of Public Works or designee. A
minimum of 3 feet of fill shall be placed over the flexible drainage pipe in areas of heavy
construction equipment crossings during construction.
13.07 Installation of Pipe
(a) The Contractor shall arrange for an inspection of the pipe by the Public Works Department
prior to installation. The inspection will include, but not be limited to, checking for
damage to pipe, including but not limited to structural cracks or defects, scratches in
protective coating, exposed reinforcing steel, and pipe thickness. Each section of pipe
shall be examined carefully before installation, and any defective or damaged sections
shall not be used. Pipe sections shall be installed to the grades and alignment indicated on
the Plans. Pipe installation shall proceed upgrade with the bell ends of drainage pipe
located upstream.
(b) Proper facilities shall be provided for lowering sections of pipe into trenches. Pipe shall
not be installed in water or when trench has loose debris or unstable trench bottom. The
Contractor is responsible for the diversion of runoff and dewatering of trenches during
construction.
(c) All pipe installation, including backfill and compaction, must be inspected and approved
by the Public Works Department. The Contractor shall be responsible for preventing
damage to or misalignment of the pipe. Pipe sections shall be visually inspected for debris
and obstructions, structural cracks and defects, deflection, alignment, joint tolerances,
joint workmanship, and satisfactory connection to drainage structures. Any drainage pipe
installation not inspected or approved by the Public Works Department will be removed
and installed properly at the sole cost of the Contractor.
13.08 Measurement and Payment
(a) Excavation, bedding, backfill, compaction, materials, equipment, tools, labor, and
incidentals must be included in the Unit Price for installation of drainage pipe.
(b) Special Bedding material, used at the direction of the Public Works Department for
unstable trench bottom, will be measured and paid for as specified in SECTION 20 - PIPE
EMBEDMENT.
(c) Completed and accepted drainage pipe will be measured by the linear foot in place, from
inside face to inside face of inlet boxes or headwalls. Separate measurements will be
made by the sizes, classes, gauges, and thicknesses shown on the Plans and listed in the
Unit Price Schedule. Measurements will be taken to the nearest 0.1 linear foot.
(d) Storm sewer pipe acceptably completed and measured as provided above will be
paid for at the contract Unit Price bid listed on the Unit Price Schedule for all drainage
pipes.