Tunnel Liner

Camino a Melipilla 17.800, Maipú, Santiago / Fono (56-2) 351 0800 / contacto@tecnovial.cl www.tecnovial.cl

GENERAL TECHNICAL CHARACTERISTICS

Tunnel Liner solution is compound by circular structures which are formed by an “M” corrugated profile with two 44.5 mm long flanges (width depends on the project). Structures may be covered in black steel or protective coating. The assembly is entirely made from the inside with bolts and nuts in the longitudinal and peripheral structure ways, and they are placed by tunneling which requires not trenches to be made.

Tecnovial counts on a certified Integrated Management System according to ISO 9001:2008 (Quality), ISO 14001:2004 (Environment) and OHSAS 18001:2007 (Safety).

USAGE

Through several decades, hundreds of kilometers of underground works have been successfully installed in most of soil types and in various usage conditions. Tunnel liner allows the construction of sewage networks, road and rail crossings, mine entries, as well as utility lines such as gas and electricity.

Through the last decade, tunnel liner has become the best solution for complex mining projects such as: ventilation tunnels, chimneys and drift tunnels, among others.

ADVENTAGES

Compared to open-air in trench structures, tunnels require less volume of excavation and no backfill. Besides, the pavement and utility lines need not to be removed and replaced, thus, reducing work costs.otorga gran seguridad en el manejo del frente de excavación.

DURABILITY

Tunnel liner provides the lifespan required for each specific project using coating and special solutions for every need, such as:

Galvanization: tunnel liner plaques are hot dipped galvanized (according to ASTM A-123 standard) being highly resistant to corrosion and increasing the structure lifespan.

Special Coatings: intended for applications in acid environments, these coatings may contain polymeric elements like: epoxy, polyester or reactive polymers (barrier type coating). Those may be applied by electrostatic deposition or liquid painted and oven dried according to the project requirements.

Concrete Coating: this coating is intended for use in extreme conditions of corrosion or abrasion. The projected concrete may ensure the structures lifespan in a practical and economical way.

PRODUCT CHARACTERISTICS

Steel Quality: A-36.

Bolts: ASTM 307 quality square neck and 5/8” diameter bolts, and hexagon head ASTM 307 quality square collar and 5/8” diameter bolts.

Holes for Mortar: 45 mm diameter.

Corrugation Characteristics: 45 mm corrugation depth; 460 mm useful length.

STRUCTURAL CALCULATION

The high structural resistance of tunnel liner is due to the steel area strength and to the confinement of the surrounding soil which prevents the structure from deformation, induces a predominantly compressive tensional state; that is why not only the conduct quality is important but also an adequate backfill of the annular space between the structure and the excavation.

In brief, during structural design there must be verified three main points:

Rigidity to Handling:It must be verified that the structure rigidity is the appropriated one to ensure a good handling during the assembly.

Bolted Joint Strength:It depends on the plates’ width only.

Unlike the trench installed conduits, tunnel liner takes advantage of the unloading (arch effect) in consolidated soil. According to AASHTO code, this reduction in the dead load is function of the properties of the soil, as shown in the following graph; this is why tunnel liner can be applied at great deepness.

MECHANICAL SECTION PROPERTIES

Area [cm2/cm]

0.32

0.39

0.45

0.52

0.65

0.78

Moment of Inertia [cm4/cm]

1.53

1.54

1.54

1.55

1.56

1.57

Radius of Gyration [cm]

41.0

55.5

69.0

79.0

116.0

137.0

Longitudinal Juncture Strength [t/m]

Width [mm]

2.5

3.0

3.5

4.0

5.0

6.0

0.75

0.91

1.08

1.25

1.58

1.91

Compressive Strength:It is determined by the mechanical characteristics of the material, as well as the geometric shapes which rule the plates’ bucking.

TunnelLiner

0 1 2 3

2

4

6

8

10

12

Values of Cd coefficient C

Val

ues

of H

/S

(rat

io o

f ove

rbur

den

to w

idth

)

TECHNICAL ADVISORY

These products design is optimized by our Engineering and Development department according to the requirements of each project and in compliance with the American Association of State Highway and Transportation Officials (AASHTO) y la American Iron and Steel Institute (AISI) standards.

INSTALLATION

The basic installation sequence is:

a) Soil excavation

b) Transportation of the excavated material

c) Assembly of the cladding plates, beginning by the main plate and going down at the sides to the base.

d) Grouting injection every 2-3 rings.

For further details on the installation sequence, please refer to our multimedia section in our Web Site:

www.tecnovial.cl/multimedia/tunnel-liner

Void spaces between tunnel liner external surfaces of the cladding plates and the soil must be backfilled to prevent soil drops or movements that can cause undesired deformations. This backfilling must be made by fluid mortar injection through holes in the tunnel liner plates. The simplicity of execution and guarantee of installation in the most varied types of soil make of tunnel liner a reliable, versatile, economic and most competitive process in its diameter range.

Please note that AASHTO allows deals with the majority of tunnel applications; nevertheless, in big major structure loads, short backfill heights, large-scale structures and special conditions of each project, the applicability of this standard is dubious. That is why Tecnovial counts on specialist professionals who are able to address most complex cases utilizing latest generation software.

MARSTON’S FORMULA

CM = Cd ∙γ∙ S

CM: Dead Load. γ: Unit Weight of Soil. S: Structure Diameter.H: Height of the Soil over the

Top of the Tunnel.

STRUCTURAL CALCULATION

NATURAL SOIL

INJECTION MORTAR

GUIDE RING

EXCAVATION FACE

EXCAVATION ADVANCE

TUNNEL LINER

ROUND HEAD SQUARE NECK BOLTS

ASSEMBLY CLIP

FLANGE

HEXAGON HEAD BOLTS

HEXAGON HEAD BOLTS

TunnelLiner

* Espesor mínimo para cumplir con rigidez de instalación y manipuleo.

AVAILABLE SHAPES

Our Engineering and Development may adapt the shape to the one that meets the requirement of each project: ellipse, pipe-arch and underpass. Standard shapes are the following.

Round

Diameter[m]

1.20

1.40

1.60

1.80

2.01

2.21

2.41

2.61

2.81

3.01

3.21

3.41

3.61

3.81

4.01

4.21

4.41

4.61

4.81

5.01

5.21

5.41

5.61

5.82

5.96

6.22

6.42

6.62

Area[m2]

3.78

4.41

5.04

5.67

6.30

6.93

7.56

8.19

8.82

9.45

10.08

10.71

11.34

11.97

12.60

13.23

13.86

14.49

15.12

15.75

16.38

17.01

17.64

18.27

18.72

19.53

20.16

20.79

Perimeter [m]

1.3

1.5

1.7

1.9

2.1

2.3

2.5

2.7

2.9

3.1

3.3

3.5

3.7

3.9

4.1

4.3

4.5

4.7

4.9

5.1

5.3

5.5

5.7

5.9

6.0

6.3

6.5

6.7

Minimum Height of the Soil over the Top of the Tunnel [m]

Minimum Width * [mm]

2.50

2.50

2.50

2.50

2.50

2.50

2.50

2.50

2.50

2.50

2.50

2.50

2.50

2.50

2.50

2.50

3.00

3.00

3.50

3.50

4.00

4.50

5.00

5.00

5.50

5.50

6.00

6.00

Model

TL-C-01

TL-C-02

TL-C-03

TL-C-04

TL-C-05

TL-C-06

TL-C-07

TL-C-08

TL-C-09

TL-C-10

TL-C-11

TL-C-12

TL-C-13

TL-C-14

TL-C-15

TL-C-16

TL-C-17

TL-C-18

TL-C-19

TL-C-20

TL-C-21

TL-C-22

TL-C-23

TL-C-24

TL-C-25

TL-C-26

TL-C-27

TL-C-28

1.14

1.55

2.02

2.56

3.16

3.82

4.55

5.34

6.19

7.11

8.09

9.13

10.23

11.40

12.63

13.93

15.29

16.71

18.19

19.74

21.35

23.02

24.76

26.56

27.89

30.35

32.34

34.40

Camino a Melipilla 17.800, Maipú, Santiago / Fono (56-2) 351 0800 / contacto@tecnovial.cl www.tecnovial.cl

HYDRAULIC DIMENSIONING

Drain steel corrugated pipes are usually dimensioned as chan-nels and the Manning Formula is applied.

TECHNICAL STANDARDS

Tunnel liner structural design is based on AASHTO– American Association of State Highway and Transportation Officials, and AISI – American Iron and Steel Institute standards.

Gauckler–Manning coefficient depends on the corrugation profile. Mean values are the following:

Corrugation Tunnel LinerConcrete Coating

n0.0240.015

Q: Cross-sectional average velocity [m3/s]. A: Cross sectional area of flow [m2]. P: wetted perimeter.i: slope of the water surface or the linear hydraulic head loss [m/m]. n: Gauckler–Manning coefficient.

MANNING FORMULA

Q = A • •AP( ) ( )√i

n