NYLEX STRIPDRAINTM is a prefabricated subsoil drainage system that consists of an HDPE inner drain core wrapped in geotextile. It is an alternative to conventional perforated pipe drainage systems. It is mainly used for drainage in roads, highways, sports fields, and other infrastructure projects. The document discusses the advantages of Stripdrain over conventional systems, provides installation guidelines, and lists example projects where Stripdrain has been used.

1. NYLEX STRIPDRAIN™
Road Drainage Edition
With Project Site Pictures
and the we-tell-you-how

2. INTRODUCTION
PRODUCT OVERVIEW
DIMENSIONS
PACKING DETAILS

3. STRIPDRAIN
 is a prefabricated & flexible subsoil drainage system to
remove underground seepage water
 consists of a HDPE inner drain core completely wrapped
with a non woven geotextile filter
 alternative to conventional perforated pipe-gravel-geotextile
systems
 mainly used for sport fields, roads, highways, parks, golf
courses, horse racing tracks, gardens, slopes

4. CONVENTIONAL
SUBSOIL DRAIN
Aggregates
Geotextiles overwrapped around
subsoil pipe (Optional)
Perforated Subsoil
Pipe
Geotextiles overwrapped
around aggregates
Sand Blanket
Top Soil

5. STRIPDRAIN
STANDARD CROSS SECTION
Sand
Backfilling
Sand Blanket
Top Soil
Nylex Stripdrain
Compacted Earth

6. ADVANTAGES OF NYLEX STRIPDRAIN
 unique “Deep-fin” geometry ensures complete
interception of seepage
 very effective for lowering of ground water table
 more than 90% surface area is permeable to water
provides higher rate of drainage
 prefabrication offers fast installation time
 narrow trench width of 150mm requires less backfill
 uses coarse sand backfill instead of gravel
 cheaper system compare to pipe-gravel systems

7. STANDARD SIZES
Product Code Size (Width x Thickness x Length)
SD100x40 100mm x 40mm x 50m
SD200x40 200mm x 40mm x 50m
SD300x40 300mm x 40mm x 50m
SD400x40 400mm x 40mm x 50m
SD500x40 500mm x 40mm x 25m

8. DESIGN
Estimation of in-flow into subsoil drain
The discharge capacity of Stripdrain
The outlet distance using Stripdrain

9. THREE IMPORTANT FACTORS
IN DESIGNING SUBSOIL DRAINAGE FOR ROAD HIGHWAYS
Estimation of in-flow
into subsoil drain
The discharge
capacity of
Stripdrain
The outlet distance
using Stripdrain

10. ESTIMATION OF IN-FLOW INTO SUB-SOIL DRAIN
• Sub-soil drainage is provided at the edge of the highway or in the median and shoulder.
• Installed near the surface, they alter the ground water regime so as to offer protection to
the road structure and sub-grade.
• The in-flow rate of water into these sub-surface drainage systems can be estimated by
considering the following sources of water:
a) Infiltration through the pavement
b) Infiltration through the shoulder or median
c) Ground water movements
(a) (a)
(b) (b) (b)
(c)

11. TOTAL IN-FLOW INTO SUB-SOIL DRAIN
• From the estimation of the water sources, the total in-flow to the sub-soil drainage system
can be estimated.
• Consider the total in-flow to the two types of sub-soil drain locations, namely the side-
table and the median.
The side table
The median

12. TOTAL IN-FLOW INTO SUB-SOIL DRAIN (THE SIDE-TABLE)
• The possible sources of water for the side-table are;
a) Qpm, transmitted through one pavement ie. (a2)
b) Qsm, infiltration through shoulder ie. (b3)
c) Qsp, interception of cut slope seepage ie. from (c)
• Therefore, the total in-flow is, Qtot = Qpm + Qsm + Qsp [l/min]
(a1) (a2)
(b1)
(c)
(b2) (b3)

13. TOTAL IN-FLOW INTO SUB-SOIL DRAIN (THE MEDIAN)
• The possible sources of water for the side-table are;
a) 2 x Qpm, transmitted through TWO pavement ie. (a1) & (a2)
b) Qsm, infiltration through median surface ie. (b2)
c) 2 x Qsp, if seepage from water table control from two sides
• Therefore, the total in-flow is, Qtot = 2(Qpm) + Qsm + 2(Qsp) [l/min]
(a1) (a2)
(b1)
(c)
(b2) (b3)

14. THE DISCHARGE CAPACITY OF STRIPDRAIN
• The discharge capacity of Nylex Stripdrain can be determined from the following
hydraulic equation which has been simplified from Manning’s formula;
Discharge capacity, Qsd = C x W x g^0.5 m3/s
= C x W x g^0.5 x 60000 l/min
C = constant taking into account Manning’s roughness factor n,
hydraulic radius Rh, etc…
For Stripdrain 40mm, C = 0.0213
W = width of Stripdrain in meter
g = gradient of Stripdrain
• A safety factor could be applied to Qsd to account for any siltation and reduction of the
cross-sectional area which might occur when Stripdrain is buried in the ground. The
recommended safety factor is F = 0.8.

15. THE DISCHARGE CAPACITY OF STRIPDRAIN
• The example of discharge capacity of Nylex Stripdrain installed at various gradients with a
safety factor of F = 0.8 is shown below;
STRIPDRAIN DISCHARGE CAPACITY [l/min]
GRADIENT g% 1% 2% 3% 4% 5%
300mm 31 43 53 61 68
400mm 41 58 71 82 91
0
10
20
30
40
50
60
70
80
90
100
1% 2% 3% 4% 5%
SD300x40 SD400x40
*Data collected from KL-Seremban Highway Project, PLUS BERHAD, MAY 1991

16. THE OUTLET DISTANCE USING STRIPDRAIN
• The maximum outletting distance, Lmax, for the Stripdrain system considering the total
rate of in-flow as determined earlier can now be computed as follow;
Lmax = Qsd / Qtot
• Table below give the values of Lmax for Stripdrain 300mm and 400mm at various installed
gradients;
STRIPDRAIN 300mm DISCHARGE CAPACITY [l/min]
GRADIENT g% 1% 2% 3% 4% 5%
MEDIAN 247 349 427 493 551
STRIPDRAIN 400mm DISCHARGE CAPACITY [l/min]
GRADIENT g% 1% 2% 3% 4% 5%
SHOULDER 540 764 936 1081 1199
*Data collected from KL-Seremban Highway Project, PLUS BERHAD, MAY 1991

17. INSTALLATION GUIDE
CONNECTIONS & DETAILS

18. CONNECTIONS AND OUTLETS
Cut slot in pipe approximately 3 mm
narrower than cross-section of core being
used, in order to hold the drain in place as
shown. All pipe-to-geotextile joints must be
sealed with tapes
Stripdrain can be connected to concrete
pipe by cutting a hole in the pipe wall and
sealing around the Stripdrains with mortar
Stripdrain can be discharged into an
open ditch using a flume to protect the
open end. Alternatively, Stripdrain can be
discharged directly into a gravel-filled
trench

19. CONNECTION
TO SUMPS
Seal around
the Stripdrain
in the sump’s
opening with
mortar &
geotextile

20. FINAL LOOK OF
STRIPDRAIN END
AT THE SUMP
The sump wall fully plastered
Sump cover

21. CONNECTION
TO COLLECTOR PIPE

22. Seal filter
with tape
STRIPDRAlN upstream ends must be covered
over to ensure that soil cannot enter the drain. This
is done simply by cutting back the geotextile for
75-100mm and pulling back to expose the core. A
section of core is removed and the geotextile
folded back and taped (suggested tape: PVC
adhesive tape).

23. STRIPDRAIN is joined simply by slitting the filter
fabric for 75-100mm and overlapping the core. The
filter fabric is then pulled back over the joint and
taped to prevent soil entry.

24. PROJECT REFERENCES
and pictures

25. PROJECT REFERENCES LIST
• North-South Trunk Road Rehabilitation Works, Perak JKR Perak
• Temerloh Mentakab By-Pass, Pahang Ledan Nippon
• Ulu Perak Border Road Project Phase I& II KTA
• Jalan Santung Dungun, Terengganu JKR Dungun
• Jerangau Jabor Highway, Terengganu JKR Terengganu
• Jalan Pecah Rotan, Terengganu JKR Terengganu
• Felda Roads, Jempol District, Negeri Sembilan JKR Unit Felda
• Kemaman Roadworks, Terengganu JKR Kemaman
• Access Road to Taman Peransang, Selayang, Selangor Berakan Jurutera Perunding
• Tasik Titiwangsa Roads Kuala Lumpur DBKL
• Roadwork in Kuching, Sarawak Hevision

26. KL-SEREMBAN
HIGHWAY

27. CAHAYA SPK
SHAH ALAM

28. THE ENDVisit our website for more
www.nylexpolymer.com
NYLEX (M) BERHAD
Lot 16, Persiaran Selangor, Section 15,
40910 Shah Alam, Selangor Darul Ehsan
T: (603) 5519 1706
F: (603) 5519 9821
For enquiry, please call:
Mr Loh T: +6013-3460 520 E: lhl@nylex.com
Mr Naza T: +6017-3399 135 E:
nazaruddin@nylex.com