NYLEX STRIPDRAIN™Road Drainage Edition

With Project Site Pictures

and the we-tell-you-how

INTRODUCTION

PRODUCT OVERVIEW

DIMENSIONS

PACKING DETAILS

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

CONVENTIONAL

SUBSOIL DRAIN

Aggregates

Geotextiles overwrapped around

subsoil pipe (Optional)

Perforated Subsoil

Pipe

Geotextiles overwrapped

around aggregates

Sand Blanket

Top Soil

STRIPDRAIN

STANDARD CROSS SECTION

Sand

Backfilling

Sand Blanket

Top Soil

Nylex Stripdrain

Compacted Earth

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

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

DESIGN

Estimation of in-flow into subsoil drain

The discharge capacity of Stripdrain

The outlet distance using Stripdrain

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

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)

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

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)

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)

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.

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

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

INSTALLATION GUIDE

CONNECTIONS & DETAILS

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

CONNECTION

TO SUMPS

Seal around

the Stripdrain

in the sump’s

opening with

mortar &

geotextile

FINAL LOOK OF

STRIPDRAIN END

AT THE SUMP

The sump wall fully plastered

Sump cover

CONNECTION

TO COLLECTOR PIPE

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).

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.

PROJECT REFERENCES

and pictures

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

KL-SEREMBAN

HIGHWAY

CAHAYA SPK

SHAH ALAM

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