pragma catafgrlog technfgdfgical

7/31/2019 Pragma Catafgrlog Technfgdfgical

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Pipelife Polska S.A.ul. Torfowa 4, Kartoszyno, 84-110 Krokowa

tel. (+48 58) 77 48 888, fax: (+48 58) 77 48 807, e-mail: [email protected]; www.pipelife.pl

CONTENTS

INDEX

1. INTRODUCTION1.1 INTRODUCTION OF PP PRAGMA SEWAGE SYSTEM

1.2 CHARACTERISTIC OF PRAGMA SYSTEM

2. HYDRAULIC DESIGN OF PRAGMA SYSTEM

2.1. GENERAL ASSUMPTIONS

2.2. GOVERNING FORMULAE

2.3 NOMOGRAPH 1

2.4 NOMOGRAPH 2

2.5 NOMOGRAPH 3

3. SLOPES AND VELOCITIES OF FLOW INPRAGMA PIPES

4. STRESS AND STRENGTH ANALYSIS OFBURIED PRAGMA PIPES4.1 INTERACTION BETWEEN THE PIPE AND THE

SURROUNDING SOIL

4.2 METHOD OF CALCULATION

4.3 LOAD

4.4 ULTIMATE LIMIT STATE MODEL

4.5 ULTIMATE LIMIT STATE MODEL STRAIN

4.7 RELATIVE STRAIN

5. EARTHWORKS5.1 GENERAL CONSIDERATIONS

5.2 BEDDING CONDITIONS

5.3 SIDEFILL, INITIAL BACKFILL AND FINAL BACKFILL

6. INSTALLATION OF PRAGMA PIPES6.1 CONNECTION OF PRAGMA-PRAGMA PIPES

6.2 CUTTING PIPE - MOUNTING SEALING RING

6.3 CONNECTION OF PRAGMA PIPE (SPIGOT) WITH PVC PIPE

6.4 CONNECTION OF PRAGMA PIPE (SOCKET) WITH SMOOTH

PVC PIPE (SPIGOT)

6.5 CONNECTION OF PRAGMA TO CONCRETE

CHAMBER(SOCKET)

7. PRODUCT RANGE

8. LITERATURE


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3/23



1

INTRODUCTION OF PP PRAGMA SEWAGE SYSTEM

INTRODUCTIONOFPPPRAGMA

1.2 CHARACTERISTIC OF PRAGMA SYSTEM

The Pragma pipes have been designed

for sanitary and rainwater sewage sys-

tems. The pipes can be used in the

industrial sewage as jacket pipes for tel-

ecomunication cables as well as draingepipes for roads, dumping grounds etc.

The raw material used for Pragma pipes

production is polypropylene co-polymer.

Pragma pipes is a twin well pipes with

a smouth inside and profiled outside

walls.

The pipes own a real mounted in the

first corrugation valley.

The adapters allows to connect Prag-

ma pipes with smooth PVC pipes.

PP Pragma sewage system consists of:

Twin wall pipes with a socket in 3 and

6 meters lengths. Scope of diameters

160 - 630 mm and ring stiffness 8

kN/m2.

Full range of fittings.

1.1

INTRODUCTION

CHEMICAL RESISTANCEPragma pipes and fittings have high

chemical resistance both for aggres-

sive sewage and an enviroment.

RESISTANT TO HIGH

TEMPERATURES

Pragma pipes and fittings have a resist-

ant to high temperature up to 60oC for

constant flow and up to 95-100oC for

brief sewage passage.

IMPACT STRENGTH

Pragma pipes and fittings are crack

resistant, including temperatures below

0

o

C (up to -20

o

C) which makes transportand assembly easy in winter conditions.

RING STIFFNESS

Ring stiffness which for the entire range

of diameters equals 8 kN/m2 puts the

system in class T.

EASY TO CARRY

Pragma pipes and fittings are very light

and yet have high ring stiffness there-

fore they are easy to transport and place

which speeds up assembling.

EASY TO ASSEMBLEPragma pipes and fittings can be eas-

ily joined with smooth-wall PP and PVC

pipes and cladding can be applied inter-

changeably in each system.

EASY TO CUT

Pragma pipes can be cut to any length

with the use of the simplest tools.


4/23



cos ) cos )qn

Motion resistance on the pipe lenght are

calculated based on unitary hydraulic

gradient.Unitary hydraulic gradient for

closed pipes with a settled turbulent

motion is calculated based on Darcy-

Weisbach formula:

Hydraulic resistance coefficient () iscalculated based on Colebrook-White

formula:

The Bretting formula for pipes flowing

partly full:

Pipelife proposes to use the following

values of k for Pragma pipes:

k = 0.00025 m, for main sewers without

special structures, equipment and any,

or only a small number, of side inlets;

k = 0.0004 m, for sewers with many

inlet pipes and structures (where minor

losses at joints are to be taken into

account).

Q = V F ; F = d2

4

Q = d2 V

4

1)

2)

In practice, for computational purposes,

the following semi-empirical equations

are used:

A hydraulic design concerns selecting

parameters for gravity flow sewers,

which normally do no flow full. The

objective of hydraulic design is to deter-

mine the most economic pipe diam-

eter at which the required dischargeis passed. In practice, computation of

hydraulic pipe parameters are based on

the following assumptions:

1. The assumption of a uniform flow,

meaning:

q the depth (h), flow area (f) and veloc-

ity (v) at every cross-section remain

constant at the whole considered pipe

section;q the energy grade line, water surface

and pipe bottom slope are parallel.

2. In the pipe system, the flow regime is

turbulent.

GENERAL ASSUMPTIONS2.1

HYDRAULIC DESIGN OF PRAGMA SYSTEM

GOVERNING FORMULA2.2


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HYDRAULICDESIGNOFPRAGMASYSTEM

2


NOMOGRAPH OF HYDRAULIC PARAMETERS2.3

NOMOGRAPH 1

PROPORTIONAL DEPTH RELATIONSHIPS FOR PARTLY FULL CIRCULAR PIPES


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NOMOGRAPH 2

DARCY-WEISBACH / COLEBROOK-WHITE FORMULA FOR GRAVITY PRAGMA PIPES

For k=0,40 mm, temp. t=1000C, full flow


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HYDRAULICDESIGNOFPRAGMASYSTEM

2

2 3 4 5 6

0,1

0,15

0,2

0,3

0,40,5

0,6

0,8

1

1,5

2

3

4568

8

10

10

10

20

20

30

30

40

40

50

50

60

60

80

80

100

100

200

150

200

300

400

500

600

800

1000

2000

3000

4000

0,30,1 0,1

50,2 0,2

5

0,4

0,5

0,6

0,8

1,0

1,5

2,0

2,5

3,0

4,0

5,0

6,0

8,0

10,0

630500

400315

250200

160

Discharge - Q[dm/s]3

nDiameter d [mm]

hydraulic

slope-i[

]

/ooo

velocity - V[m/s]



NOMOGRAPH 3

DARCY-WEISBACH / COLEBROOK-WHITE FORMULA FOR GRAVITY PRAGMA PIPES

For k=0,25 mm, temp. T=1000C full flow


8/23



SLOPES AND VELOCITIES OF FLOW IN PRAGMA PIPES SLOPESThe slope of the channel must also be

considered as variable, since it is not

necessarily completely defined by topo

graphic conditions.

The minimum channel slope is required

to achieve the lowest flow velocity which

will prevent suspended solids from set-

tling out and clogging the pipe.

In general, solid particles, e.g. sand

particles, can deposit on the bottom

to a depth corresponding to the par-

ticle friction angle (see Figure 3.1),expressed as:

The area of deposition may be allowed

to a relatively flat zone of the channel

bottom.

Figure 3.1 Angle of friction

The safe lower limit of velocity to avoid

sedimentation depends on the type of

sediments. Usually, the permissible

minimum velocities (Vsc) which ensure

When determining the slope of the pipe-

line, one should select the permissible

velocities taking into account the pipe

diameter. To this end, a simple formula

can be used:

The minimum slope of the sewer pipe-

line can also be expressed by the trac-

tive force (t), given as:

The actual tractive force is:

From the above, the critical tractive

force for the actual depth of flow (hn) is:

The critical tractive force which fulfil the

condition of the channel self-cleaning

is:

Thus, from Equation 9, after rearrang-

ing, the minimum slope of the pipe is:

self-cleaning of the channel should not

be, at full flow, lower than:

Vsc = 0.8 m/s for sanitary sewers

Vsc = 0.6 m/s for storm sewers

Vsc = 1.0 m/s for combined sewers

h

n

d

()


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STRESS AND STRENGTH ANALYSIS OF BURIED PRAGMA PIPES

INTERACTION BETWEEN THE PIPE AND THE SURROUNDING SOIL

From the technical point of view, the

plastic Pragma pipe is a flexible struc-

ture having a high ability to take up

stress without failing. The classical

method to evaluate the strength of a

structural material is to describe theactual relation between the stress and

the strain when the material is loaded.

A vertical load imposed on the pipe

causes a deflection (dv), a reduction in

the vertical diameter of the flexible pipe,

which takes causes it to take an elliptical

shape (see Figure 4.1).

Figure 4.1 Deflection of circular pipe

due to vertical load

Deflection of the pipe causes bend-

ing stress in the pipe wall and exerts

pressure on the surrounding soil, and

the passive earth pressure decreases

the bending stress in the pipe wall. The

bending stress in the pipe wall caused

by deflection is in momentary balance

with the soil pressure acting against the

outside of the pipe wall. The force the of

the soil counteracting the pipe pressure

depends on the vertical load, soil type

and stiffness (density) in the pipe zone

and on the pipe stiffness.

For rigid pipes such as concrete, etc.,

the pipe alone has taken the main verti-

cal forces acting on the pipe, while flex-

ible pipe makes use of the horizontally

acting soil support exerted as a result

of the pipe deflection. Consequently,

for the flexible pipe, the integration

between the soil and the pipe has to beconsidered far more extensively than in

the case of rigid pipes.

The design concept of flexible pipes can

be explained with the classical Spangler

formula:

Equation (11) describes the relative

deflection of a pipe subjected to a verti-

cal load (qv) supported by the pipe ring

stiffness and the soil stiffness.

This equation clearly shows that pipe

deflection can be limited to the permis-

sible magnitude by increasing one or

both of the two factors, pipe ring stiff-

ness and soil stiffness in the pipe zone.

Additionally, it can be said that pipe with

greater ring stiffness is less subjected

to interaction with the soil and is less

dependent on the soil density in the

pipe zone. Whereas application of a

suitable enbedment of properly com-

pacted material (higher cost of installa-

tion) enables the use of pipes of lower

ring stiffness (lower in cost), in making a

decision both the engineering and eco-

nomic advantages of the alter-natives

must be considered.

4.1

STRESSANDSTRENGHTANALYSISOFBURIEDPRAGM

APIPES

4

Buried Pragma pipes can be calculated

with the ultimate limit state model:

q serviceability limit state can be

checked by comparison of the strain

caused by the load to the allowable

strain;

q ultimate bearing resistance state can

be checked by comparison of the

buckling stress with the compressive

stress as well as the relative strain

with the allowable strain (d).

In the following, the calculation for

flexible pipes according to the method

referred to as the Scandinavian Method

[Janson, Molin 1991] (SM) is described.

This is an analytical method based on

the soil pressure distribution in the pipe

zone shown in Figure 4.2. In it, the inter-

action between the pipe and the sur-

rounding soil is taken into account.

The maximum load which is likely to be

imposed on the pipe should be estimat-

ed ac-cording to the obligatory national

standards. The influence of a traffic load

can be cal-culated by the pressure dis-

tribution according to the Boussinesque

[PN-81/B-03020] theory.

METHOD OF CALCULATION4.2


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SYMBOLS USED IN FORMULA

qv - vertical load

qh - horizontal load

qz - load due to soil cover

qt - trafc load

qw - water pressure

gz - unit weight of the soil

gzw - water saturated unit weight ofthe soil

gw - unit weight of water

P - load of vehicle wheel

C - coefcient of trafc load

H - depth of pipe cover (from ground

level to the pipe crown)

h - height of water over the pipe

axis

D - initial undeformed diameter of

the pipe

dn - nominal inside diameter of the

pipe

r - radius of the pipe

dv - vertical deection of the pipe

SN - pipe ring stiffnessI - moment of inertia of pipes

cross wall section

E - modulus of elasticity of the pipe

- also called the creep modu-

lus which describes a creep

(increase of strain) on a con-

stantly stressed material, as well

as the relaxation modulus which

describes a relaxation (decrease)

of stress on a constantly strained

material

Es - secant modulus of the soil

Et - tangent modulus of the soil

F - safety factor against buckling,

F = 2 - strain in the pipe wall

These symbols are given without

numerical quantities, making it possible

to use the most convenient units. In the

Tables and Graphs, SI units are used.

The soil pressure distribution for theScandinavian Method [by Janson, Molin

1991] is shown in Figure 4.2. The buried

pipe is loaded with vertical load (qv),

which causes stress and strain, and with

the counteracting horizontal load (qh).

Figure 4.2 Scandinavian Model of soil

pressure distribution

VERTICAL LOADS

1. Load due to soil above the pipe:

In this case, vertical load is:

Under normal conditions of pipe installa-

tion, the vertical load (qv) component is

larger than the horizontal load (qh) com-

ponent. The difference (qv - qh) causesa reduction of the vertical pipe diameter

and an increase in the horizontal pipe

diameter. The pipe side walls, when

deforming, mobilise a passive earth

pressure of a value depending on the

imposed vertical load and on the ratio

between the soil stiffness and pipe stiff-

ness. This last is expressed as the pipe

ring stiffness (SN).

The components of load which are likely

to be imposed on a pipe in the vertical

plane are:

the effect of the soil above the pipe

the effect of loads superimposed onthe surface of the ground, such as those

from buildings, vehicle wheel loads, etc. Figure 4.3 Geometry of buried pipe

For pipes below the water table, the

total pressure shall be increased with

the hydrostatic pressure:

LOAD4.3



11/23

STRESSANDSTRENGHTANALYSISOFBURIEDPRAGM

APIPES



LOAD SUPERIMPOSED BY TRAFFIC

Figure 4.4 Traffic load coefficient

relationship

SERVICEABILITY LIMIT STATE

- DEFLECTION

Deflection of a buried gravity pipe

depends on the magnitude of external

loads, pipe ring stiffness, the specific

weight of the soil, type and composition

of the backfill material and the method

of installation.

A theoretical deflection caused by loads

can be calculated from the following for-

mula [by Janson, 1995]:

Figure 4.5 Minimal secant modulus

(ES) values for granular soils versus

depth of pipe cover (H) at variousdegrees of soil compaction

The secant modulus (Es) of the soil in

the pipe bedding zone depends on the

degree of soil compaction and the effec-

tive soil pressure.

Values of the secant modulus (Es) for

granular materials have been deter-

mined by laboratory tests in a hollow

cylinder apparatus (on moraine sand,

among others).

ULTIMATE LIMIT STATE MODEL4.4


4

2,0 2,5 3,0 3,5 4,0 4,5 5,0 5,5 0,0 6,5

for road I and II technical grade - A

loading grade

for road III, IV and V technical grade -

B loading grade

for higher technical class - C loadinggrade

ground water level below the pipe

5000

4000

3000

2000

1000

0

90%

85%

80%

75%

E [kN/m ]s2

consolida

tiongrad

e


12/23



4

The initial deflection caused by

external loads for pipes bedded in

non-cohesive soils (sand, gravel) is

in the range of 2 to 4%.

The maximum initial deflection can be

estimated as follows:

The value of the installation factor (UI) is

influenced mainly by:

trench shape (see Figure 4.6); equipment and method of soil compac-

tion (see Figure 4.7);

trafc load during construction (see

Figure 4.8).

Figure 4.6 Stepped trench

Figure 4.7 Compaction with heavy

equipment (useful load > 0.6 kN)

Figure 4.8 Heavy traffic at shallow

depths

The value of the bedding factor (UB)

depends on:

unevenness in the pipe bed;

quality and quantity of construction

supervision;

skill of the installation personnel.

Figure 4.9 Bedding conditionsa) uneven pipe bedding (with large

stones)

A number of measurements on opera-

tional PP sewers show that a great part

of deflection results from the installation

method and uneven pipe bed conditions.

Therefore, installation and bedding fac-

tors should be added to the theoretical

deflection calculated in Equation 16.



13/23



b) bedding material not placed evently

The suggested values of factors UI and

UB are given in Tables 4.1 and 4.2, pro-

vided that sand or gravel is used for the

pipe surrounding fill.

The average initial pipe deflection can

be determined by excluding the factorUB in Equation 18.

With careful execution of installation,

the mean initial value of deflection

should not exceed 5%.

The maximum initial deflection of PP

gravity sewer pipes should not exceed 9%.

It is well known that buried plastic pipes

undergo deflection in the course of

time. Final pipe deflection is a function

of changes in the soil stiffness in the

course of time due to settlement of the

trench fill and movement of soil particles

in the embedment soil.

Therefore, in order to determine the

final pipe deflection after 1 to 3 years,

one should replace Equation 16 with the

formula:

The maximum final deflection of the

PP gravity sewer pipe is given by the

formula:

The functional requirement for pipe

deflection is that pipe on a long term

basis shall be water-tight and not

essentially change its transport capac-

ity. This has led to the require-ment that

the maximum long-term deflection must

not exceed 15%.

Table 4.1 Values for the installation factor (UI)STRESSANDSTRENGHTANALYSISOFBURIEDPRAGM

APIPES

4

Figure 4.10 Bedding conditions

Table 4.2 Values for the installation factor (UB)



14/23



External pressure causes compressive

ring forces in the pipe wall. When these

forces are large they can cause failure

due to buckling of the pipe wall.

In the circumferential direction, it is acombination of large external pressure

(or internal vacuum) and low pipe stiff-

ness that creates the risk of buckling.

In firm soil, the embedment substan-

tially increases the ability of the pipe

to resist buck-ling. In this case buckling

will occur in a small wavy pattern. How-

ever, if the surround-ing soil is weak, itscontribution to the buckling resistance is

smaller. In such conditions, the buckling

Figure 4.11 Types of Buckling

In firm soils, the permissible external

pressure due to the risk of buckling can

be calcu-lated by the following formula

(Jonson, Molin, 1991):

In cases where the pipe is surrounded

by weak soil (e.g. soft silt or clay), the

permissible pressure can be calculatedaccording to the expression which holds

for elliptical buckling, as follows:

Under the condition that:

When the pipe deflects to v/D, a strain

(and stress) is caused in a circumferen-

tial direction in the pipe wall. The magni-

tude of this strain can be expressed as:

will occur in a more or less elliptical

shape, presented in Figure 4.10. (by

Jonson, Molin, 1991).


ULTIMATE LIMIT STATE MODEL - STRAIN4.5

RELATIVE STRAIN4.6


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A bedding design depends on the soil

geotechnical characteristics of the zone

in which the sewer pipe is to be laid.

In general, two methods of pipe beddingcan be considered:

BEDDING ON NATURAL GROUNDIn some instances, it may be acceptable

to lay Pragma pipe on the bottom of

the trench, but only in granular, dry soil

which is free of large stones (> 20mm),

such as gravel, coarse sand, fine sand

and sandy clay.

In such soil conditions, the pipe is laid

on the thin (10 to 15cm), uncompactedbedding directly underneath the pipe.

The purpose of the bedding is to bring

the trench bottom up to the grade and to

provide a firm, stable and uniform invert

support of a minimum 90 angle (see

Figure 5.1). Figure 5.1 Natural bedding

BEDDING ON A FOUNDATION

There are situations where a pipeline

should be laid on a foundation. Theseinclude:

1. when in favourable natural ground

conditions, the trench is mistakenly

overcut to a depth below the designed

pipe level;

2. in rocky soils, cohesive soils (clays)

and silty soils;

3. in weak, soft soils, such as organic

silts and peat;

4. in any other conditions where the

project document requires a founda-

tion.

natural bedding on the native undis-

turbed ground;

bedding on a foundation made of

selected soil material, compacted tothe required level.

An example of the solution for cases 1

and 2 is presented in Figure 5.2. Thepipeline is laid on two layers made of

sandy soils or gravel soils with maxi-

mum size of 20mm.

The foundation layer is made of well

compacted soil of thickness 25cm

(minimum 15cm).

The bedding layer is 10 to 15cm thick,

uncompacted.

In the case of weak soils, depending

on the thickness of the weak soil layer

below the designed pipeline level, two

solutions can be applied.

1. Where the thickness of the weak soil

layer is

1.0m (see Figure 5.3).In this case, the weak soil is removed

and the trench is filled with a well-com-

pacted layer of a broken stone and

sand mixture (volume ratio 1:0.3) or a

broken stone and sand mixture (volume

ratio 1:0.6). The foundation is laid on a

geotextile.

2. Where the thickness of the weak soil

layer is > 1.0m (see Figure 5.4).

In this case, a 25cm thick foundation

made of a well-compacted layer of a

gravel and sand mixture (volume ratio 1:

3) or a broken stone and sand mixture

(volume ratio 1:0.6) laid on a geotextileis recommended.

The most important factor in achiev-

ing a satisfactory installation of flexible

conduit is the interaction between the

pipe and the surrounding soil. Most of

the pipe support is accomplished by the

soil around the lower half of the pipe

and horizontally away from the pipe in

both directions. Thus, the soil type and

degree of compaction realised in the

pipe zone are great importance. There-

fore, in any pipe installation project, the

designer must determine the conditions

for the pipe bedding, such as:

1. the ground conditions and the suit-

ability of the local soil for the pipe

bedding;2. the geotechnical characteristics for

the soil used for bedding, haunching

and initial backfill, as well as the man-

ner in which they are placed;

3. the suitable class of pipe stiffness.

To this end, the first step in any design

is a geotechnical investigation along the

entire pipe route. Routine field inves-

tigations and laboratory testing must

be carried out to provide the requiredground parameters, such as soil class

and structure, gainsize distribution,

compactability and ground water level.

EARTHWORKS

5

GENERAL CONSIDERATIONS5.1

EARTHWORKS

BEDDING CONDITIONS5.2

1- native soil2- bedding layer

90 120

2

1

0 0

d n


16/23



Figure 5.2 Example

of a foundation in

firm soil

Figure 5.3 Foun-

dation in weak soil

of depth 1.0 m

Figure 5.4 Foundation in weak

soil of depth > 1.0 m

In all cases, the foundation layer must

be compacted to 85 to 90% of modified

Proctor test density.

Apart from a proper foundation and bed-

ding, the soil class and density realised

in the sidefill (haunching) and initial

backfill are important factors in achiev-

ing a satisfactory installation of a flexible

pipeline.

Figure 5.5 Pipeline cross-section

SIDEFILL AND INITIAL BACKFILL

The criteria to select material as suitable

to use as fill in the haunching zone (side-

fill) and directly above the crown of the

pipe (initial backfill) are based on achiev-

ing ade-quate soil strength and stiffness

after compaction. Suitable soil material

includes most graded, natural granular

materials with maximum particle size

not exceeding 10% of the nominal pipe

diameter or 60mm, whichever is smaller.

The fill material should not contain for-

eign matter such as snow, ice or frozen

earth clumps.

Table 5.1 Characteristics of sidefill and initial backfill material

SIDEFILL, INITIAL BACKFILL AND FINAL BACKFILL5.3

a)

natie soil (very weak)

solid native soil

h 1m

90 120

2

1

3

dn

0 0

c

d

ba

10 cm

e 15cm

30 30D

30 cm

B D+2 x03

1- soil fundation layer as: gravel and sand

mixture or broken stone sand mixture

2- bedding layer

3- geotextile

a- main backfill

b- cover depth

c- pipe zone

d- bedding if requirede- fundotion if required

EARTHWORKS


17/23



EARTHWORKS

5

DEGREE OF COMPACTION

The required degree of fill compaction

depends on loading conditions.

In paved areas, the minimum soil

compaction in the pipe zone is 90% of

modied Proctor test density.

Outside of paved areas, the ll should

be compacted to:

- 85% of modied Proctor test density if

the depth of cover is < 4.0 m;

- 90% of modied Proctor test density if

the depth of cover is 4.0 m.

The fill material should be compacted to

layers of 10 to 30 cm in thickness.

The thickness of the initial backfill over

the crown of the pipe should be:

minimum 15 cm for a pipe of diameter

D < 400 mm;

minimum 30 cm for a pipe of diameter

D 400 mm.

FINAL BACKFILL

The material used for completing the

backfilling can be made with exca-

vated material if suitable to achieve the

required project compaction and can

have maximum particle size of 300 mm.

For pipelines of diameter D < 400 mm

and with an initial backfill thickness of 15

cm, the final backfill material should not

contain particles of size > 60 mm.

In paved areas, the minimum compac-

tion of the final backfill should be 90% of

modified Proctor test density.

TAMPING THE EMBEDMENT

MATERIAL

The requirements for the degree of

compaction depend on the load condi-

tions and should be given in the project

document. Tamping can be done with

different tamping equipment. Depend-

ing upon the equipment, thickness of

layers and soil compactability, different

degrees of compaction can be achieved.

In Table 5.2, some data is given which is

valid for gravel and sandy soils.

Table 5.2 Compaction methods

TRENCH WIDTH

The width of the trench should enable

the proper placement and compaction

of the fill material. The minimum width

of the sidefill is bmin = 30 cm. Thus, the

minimum width of the trench (B) at the

top of the pipe is: bmin)

dn

If the stiffness of the native undisturbed

ground is lower than the stiffness of the

designed fill, the trench width (B) should

be:

(in general, this condition deals with

pipes in diameter dn > 250 mm because

for pipes of smaller diameter the trench

width (B) fills this condition)

Such situations can take place in granu-

lar soils of low density (ID < 0.33) or in

cohesive soils of plastic limit IL > 0.0.

EARTHWORKS


18/23



CUTTING PIPE - MOUNTING SEALING RING6.2

CONNECTION OF PRAGMA PIPE (SPIGOT) WITH PVC PIPE6.3

1) To clean the socket, seal and thespigot of the pipe. 2) To lubricate the seal. 3) To push a spigot into a socket.

Cut pipe in a corrugation valley, using a

fine tooth carpenters saw. Mount seal-

ing ring in first corrugation valley.

1) To examine and clean a socket, seal-ing ring and Pragma spigot.

2) To lubricate a seal in a socket. To

push a coupler into a socket.

CONNECTION OF PRAGMA-PRAGMA PIPES6.1

INSTALLATION OF PRAGMA PIPES


19/23



6

INSTALLATIONOFPRAGMAPIPES

1) To make a whole in a concrete cham-

ver.

2) To fix a Pragma adapter. 3) To connect pipe to the adapter.

CONNECTION OF PRAGMA TO CONCRETE CHAMBER(SOCKET)6.5

1) To put the seal into the inside groove

of a socket on the edge of the socket

to install click-ring.2) To drive the click (using rubber ham-

mer).

3) To lubricant a seal.

4) To push a spigot into a socket.

CONNECTION OF PRAGMA PIPE (SOCKET) WITH SMOOTHPVC PIPE (SPIGOT)

6.4

INSTALLATION OF PRAGMA PIPES


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PRODUCT RANGEPIPES

FITTINGS

Pragma double walled sewer pipe

PPPragma bend

SEWER PIPESAND FITTINGSOF Pragma SYSTEM

PRODUCT RANGE

d

[mm]

L

[m]

t

[mm]160

200

250

315

400

500

630

160

200

250

315

400

500

630

6,0

6,0

6,0

6,0

6,0

6,0

6,0

3,0

3,0

3,0

3,0

3,0

3,0

3,0

94

113

129

148

158

188

232

94

113

129

148

158

188

232

dn

Lt

n

d[mm]

Z[mm]

Z[mm]

[ ]t

[mm]A

[mm]

160

160

160

200

200

200

200

250

250250

250

315

315

315

315

400

400

400

400

500

500

500

500630

630

630

630

110

121

149

134

159

158

442

186

203287

459

197

218

320

533

222

250

366

615

241

275

399

679285

328

477

818

15

30

45

15

30

45

90

15

3045

90

15

30

45

90

15

30

45

90

15

30

45

9015

30

45

90

21

31

41

23

176

48

459

161

178261

434

169

217

320

533

220

248

363

613

238

272

396

679284

327

476

817

97

97

97

116

113

116

113

129

129129

129

148

148

148

148

158

158

158

158

188

188

188

188232

232

232

232

110

108

116

119

132

119

132

170

170170

170

176

176

176

176

196

196

196

196

208

208

208

208244

244

244

244

AZ

Z

1

2

tdn

n 1 2

PP Pragma concrete chamber adapter

d[mm]

n

d

A

n A[mm]

160

200

250

80

80

80

315400 8080


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6

PRODUCTRANGE


22/23




23/23

7. LITERATURE

BN-83/883-02 Przewody podziemne. Roboty ziemne. Wymagania i badania przy odbiorze.

BN-67/8936-01 Drogi samochodowe. Odprowadzanie wd opadowych z drogi. Wskaniki techniczne wykonania i odbioru.

BN-72/8932-01 Budowle drogowe i kolejowe. Roboty ziemne.

BN-91/8836-06 Roboty podziemne. Roboty ziemne. Wymagania i badania przy odbiorze.

Geotextiles and geotextile - related produucts - classifications scheme (draft). Document No. 95/BSI STANDARDS, November

1995

ISO-4422-2. Pipes and fittings made of unplasticized poly(vinyl chloride) (PVS-U) for water supply - specifications

Technische Lieferbedingungen fur Geotextilen und Geogitter fur den Erdbau im trassenbau TL Geotex E-StB 95-1995

European standard. Preliminary draft. EN(155WJO19). Plastic piping system for water supply - PVC-U. February 1992.

ISO/TC 138/SC 2. Draft technical report. Polyethylene (PE, pipes for conveyance of water under pressure. Recommended

practice for laying. 1985.

Bolt A.: Programowanie bada geotechnicznych dla celw posadowienia sieci wodnokanalizacyjnych z tworzyw sztucznych.

Inynieria Morska i Geotechnika Nr 4, 1997

Bolt A.F.:, Duszyska A.: Kryteria doboru geosyntetykw jako warstw separacyjncyh i filtracyjnych. Inynieria Morska i Geo-

technika, Nr 1, 1998

Janson L.E., Molin J.: 1991, Design and installation of buried plastic pipes. Stockholm, Akaprint ApS, Aarhus

Janson L.E.: Plastic Pipes for Water Supply and Sewage Disposal, Stockholm, 1995

Polyethylene Pipe System Handbook, Mabo AS. Oslo, Norway.

Polyethylene pipe systems for water supply. Manual, WRC Swindon 1994.

PVC Pressure pipe systems. Manual. WRC Swindon, 1994

Tullis J.P.: 1989; Hydraulics of Pipelines. John Wiley & Sons, New York, USA LITERATURE

7

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