J

Research Report KTC-98-13

FIELD PERFORMANCE REPORT ON 1219 MM HDPE (48-INCH) ON US 127

OWEN COUNTY

by

L. John Fleckenstein Senior Principal Research Investigator

and

David L. Allen Chief Research Engineer

Kentucky Transportation Center College of Engineering University of Kentucky

Lexington, Kentucky

in cooperation with Transportation Cabinet

Commonwealth of Kentucky

and

Federal Highway Administration U.S. Department of Transportation

The contents of this report reflect the views of the

authors who are responsible for the facts and accuracy

of the data presented herein. The contents do not

necessarily reflect the official views or policies of

the University of Kentucky, the Kentucky Transportation

Cabinet, nor the Federal Highway Administration. This report

does not constitute a standard, specification, or regulation.

The inclusion of manufacturer names and trade names are for

identification purposes and are not to be considered as endorsements.

July 1998

Technical Report Documentation Page1

1. Report No. KTC-98-13 2. Government Accession No. 3. Recipient's Catalog No.

4. Title and Subtitle 5. Report Date July 1998

FIELD PERFORMANCE REPORT ON 1219 MM

HOPE PIPE ON US 127, OWEN COUNTY 6. Performing Organization Code

7. Author(s) L. John Fleckenstein and David L. Allen 8. Performing Organization Report No.6

KTC-98-13

9. Performing Organization Name and Address 10. Work Unit No. (TRAIS)

Kentucky Transportation Center 11. Contract or Grant No.

College of Engineering University of Kentucky

13. Type of Report and Period Covered

FINAL 12. Sponsoring Agency Name and Address

Kentucky Transportation Cabinet State Office Building 14. Sponsoring Agency Code

15. Supplementary Notes Pub~cation of this report was sponsored by the Kentucky Transportation Cabinet in cooperation with the U.S. Department of Transportation,

Federal Highway Administration

16. Abstract.

This report documents the installation and performance of a 1219 mm (48-inch) corrugated smooth lined polyethylene (HDPE) pipe

installed during reconstruction of US 127 in Owen County. The pipe installed was manufactured by Advanced Drainage Systems, Inc.,

and is designated as ADS N-12. pipe.

The culvert was installed in a 6~meter (20~foot) high embankment. The culvert pipe was installed in two sequences. The first half of the

structure was bedded and backfilled with No. 8 s't?ne and the second half of the structure was bedded and backfilled with pipe sand

(crushed limestone).

The pipe appears to be performing well. The average deflection is approximately 1.0 to 1.5 percent. The maximum deflection recorded

was 2.5 percent.

17. Key Words 18. Distribution Statement

Backfill Compaction

Unlimited

Performance

19. Security Classlf. (of this report) 20. Security Classlf. (of this page) 21. No. of Pages 22. Price

UNCLASSIFIED UNCLASSIFIED 10

l Form DOT 1700.7 (8-72) Reproduction of completed page authorized

l

EXECUTIVE SUMMARY

This report documents the installation and performance of a 1219 mm ( 48-inch) corrugated

smooth lined polyethylene (HDPE) pipe installed during reconstruction ofUS 127 in Owen

County. The pipe installed was manufactured by Advanced Drainage Systems, Inc., and

is designated as ADS N-12. pipe.

The culvert was installed in a 6-meter (20-foot) high embankment. The culvert pipe was

installed in two sequences. The first half of the structure was bedded and backfilled with

No.8 stone and the second half of the structure was bedded and backfilled with pipe sand

(crushed limestone).

The pipe appears to be performing well. The average deflection is approximately 1.0 to 1.5

percent: The maximum deflection recorded was 2.5 percent.

l

]

TABLE OF CONTENTS

FORM DOT 1700.7 (8-72) ........................................ i

EXECUTIVE SUMMARY ........................................ ii

TABLE OF CONTENTS AND LIST OF FIGURES . . . . . . . . . . . . . . . . . . . iii

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

CONSTRUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

DEFLECTION MONITORING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

CONCLUSIONS AND RECOMMENDATIONS ....................... 7

LIST OF FIGURES

Figure 1. No.8 stone being placed for bedding (l't 120 feet of pipe).

Figure 2. No.8 stone being compacted around the springline. Figure 3. No.8 stone used for backfill to 1-foot above crown of the culvert.

Figure 4. Photo showing remainder of temporary retaining structure which damaged a

portion of the culvert. Figure 5. A.D.S. employee repairing damaged section of pipe with extrusion welder.

Figure 6. Photo showing where cracks were repaired with extrusion welder.

Figure 7. "Pipe sand" bedding being prepared for the final section of the culvert.

Figure 8. Final portion of culvert being constructed on November 21, 1997.

Figure 9. Final section backfilled to 1-foot above the crown of the pipe with pipe sand.

Figure 10. Showing profile of backfill, monitoring points, and backfill material.

Figure 11. Pipe deflections for pipef? backfilled with No.8 stone (monitoring points 0

through 5) Figure 12. Pipe deflections for pipes backfilled with pipe sand (monitoring points -1

through -5) Figure 13. Predicted pipe deflections from Burns and Richard Solution with changing fill

heights and backfill strengths).

-111-

l

I

INTRODUCTION

The Kentucky Transportation Center was requested by the Kentucky Transportation

Cabinet to monitor the construction and field performance of a corrugated, smooth-lined,

48-inch polyethylene pipe cross drain on US 127 in Owen County (Project NO. DSB-MA

127-1(77)).

CONSTRUCTION

The embankment and cross drain were constructed in two sequences. The west side of the

embankment and the inlet end of the culvert were constructed in the first sequence. The

pipe was installed by Rifle Coal Company. On November 11, 1996, approximately half of

the culvert was installed (36.6 m (120 feet)). The pipe was bedded on approximately 0.46

m to 0.61 m (1.5 to 2 feet) of No.8 Stone (Figure 1). No. 8 stone was also used to backfill

around the pipe (Figure 2). The lifts were constructed and compacted in 0.3-m (1-foot)

increments. The pipe was incased with No. 8 stone to a height approximately 0.3 m (1 foot)

above the crown ofthe pipe (Figure 3). The remainder of the embankment was constructed

with local bench material consisting of clay and limestone.

Figure 1. No.8 stone being placed for bedding (1''

120 feet of pipe)

1

Figure 2. No. 8 stone being compacted

around the springline.

2

Figure 3. No. 8 stone backfilled to 1-

foot above the crown of the culvert.

Prior to the construction of the remammg sections of the culvert, the contractor

constructed a temporary retaining structure on the outlet end of the pipe to temporarily

hold the embankment away from existing US 127. The structure was constructed oflarge

slabs oflimestone that had been exposed and excavated during earth work (Figure 4). Part

of the structure had been placed over the outlet end of the pipe. The resident engineer

requested that the structure be removed, aware of the possible damages that could be done

to the drainage structure. Prior to the removal of the wall, it is apparent that the wall

caused some initial damage to the structure. The load on the unsupported end of the pipe

caused tension in the crown of the pipe approximately 6 feet back from the outlet end. As

a result of the tension, radial cracking had occurred in approximately three areas. The

cracks propagated from the crown down to the springline on each side. Employees of ADS

repaired (patched) the cracks on April23, 1997 with an extrusion welder (Figure 5 and 6).

To date, the cracks do not appear to be affecting the performance of the structure.

Figure 4. Photo showing remainder of temporary retaining structure

which damaged a portion of the culvert.

3

1

l

Figure 5. A.D.S. employee repairing damaged section of

pipe with extrusion welder.

Figure 6. Photo showing where

cracks were repaired with extrusion

welder.

On October 2land 22, 1997 the remainder of the cross drain was installed. The pipe was bedded and backfilled with a processed pipe bedding sand made of crushed limestone (Figures 7 - 9). A cross section of the final embankment is shown in Figure 10.

Figure 8. Final section of culvert being constructed on November 21, 1997.

Figure 7. ''Pipe sand" bedding being prepared for final section of the culvert.

Figure 9. Final section backfilled with pipe sand to 1-foot above the crown of the pipe.

....,_,... """'';<''~'"" .....

'ii)

ffi

10

48-INCH HOPE CROSS DRAIN

US 127, OWEN COUNTY

~---- .. ~·-.-.!

ti 5 ·----------------------------------·------------------------------------------------------------------------------------------------------------------------------------

::i!l ..... ..J ..J u: I.&. 0 :I:

~ w :I:

48-INCH CROSS DRAIN •''·--'-!, ·-·~::::::::~':;_·j;-,'

BACKFIUI:i:DW/ N0.8 STONE BACKFILLED WI PIPE SAND 0

6 4 3 2 1 0 -6 -4 -3 -2 -1

-5 0 SA 11.5 fl.7 23.7 Zl.7 32.9 35.4 39.1 45.1 51.2 57.3 63.4 65.5

DISTANCE FROM INLET (METERS)

Figure 10. Showing prof"Ile of the baclUill, monitoring points, and backfill material.

6

!

J

I I .

DEFLECTION MONITORING

Monitoring points were placed in each section of pipe prior to backfill. Readings have been

taken since construction. The last readings were taken on July 1, 1998. Deflection data are

shown in Figure 11 and 12. The maximum pipe deflection recorded was approximately 2.5

percent. It is apparent from the figures that the deflections have stabilized. There also

appear to be a slight difference in the performance of the pipe due to the two different

backfill materials. Figure 11 indicates that the pipe sections (zero through 5) having

backfill with No.8 stone have slightly less deflection than those sections ( -5 through-!) that

were backfilled with pipe sand (Figure 12). In addition, the embankment height on the

average is higher over the first sections of pipe.

CONCLUSIONS AND RECOMMENDATIONS

The importance of the interaction between the flexible pipe and the backfill cannot be

overstressed. To keep the pipe in ring compression, it is critical to provide high shear

resistance at the haunches and sides of the pipe. This implies that a material having a

large angle of internal friction would provide the best side support for the pipe.

Manufactured aggregates are the most appropriate materials to provide and maintain high

side resistance. In the case of this installation, a good backfill and bedding material was

used resulting in a good installation with low vertical and horizontal deflections. The

importance of good backfill is also illustrated in Figure 13 which was generated from

computer runs using the Burns and Richard Solution. The solution illustrates that as the

strength of the backfill is increased vertical deflections decrease. The solution also indicates

that, in the case of this installation, the fill height could have been increased two fold and

the deflections would have remained well below the design value of 5 percent. It is

recommended that No. 8 stone be used on all flexible pipe installations in the future. It is

also recommended that the permissible fill heights for HDPE pipe be increased with the

stipulation that processed stone be used for bedding and backfill.

7

US 127,1219 mm (48-lnch) HOPE Pipe ._ov

1.50 --oH

1.00 1V

*-1H £: 0.50 *-2V 0

~ 0.00 e-2H -.... ~ -0.50 ';:R 0

-1.00

3V -3H, ' I

4V

-1.50 4H

-2.00 5V 5H Time Since Installation (Days)

Figure 11. Pipe deflections for pipe sections backfilled with No. 8 stone (monitoring points 0 through 5)

8

-- '""»'-- -·~·"~-- ~~;'"""'""" ..-"""''"''"""'"' .... __ .,. ,..,,.,,~ .. "'~' ·----..1

US 127, 1219 mm (48-lnch) HOPE Pipe 1

0.5

0 .... 0 i= -0.5 0

!W -1 ....I

1.1.. w ~ -1.5 ~

-2

-2.5

-3 TIME SINCE INSTALLATION (DAYS)

+--1V

t~--1H

-2V II 1

-fr--2H

*--3V

ft--3H

--+---4V

--4H -5V

-5H I·

Figure 12. Pipe deflections for pipes backfilled with pipe sand (monitoring points -1 through 5)

9

...JZ <CO o­..... 1-1-0 a::w W...J >LL

w ?ftc

BURNS AND RICHARD SOLUTION 12

10

8·

6

4

2

0 4 6 8 10 12 14

FILL HEIGHT (METERS)

• 200

400

600 )( 800

)I( 1000

• 1200

--+--1400

- 1600

1800

2000

Figure 13. Predicted pipe deflections form Burns and Richard Solution with changing fill heights and backf"Ill strengths.

10