Geobrugg VX Series User manual

Attending testing institute:
Swiss Federal Institute for
Forest, Snow and Landscape
Research WSL
Birmensdorf, Switzerland
Date: 07/11/2016
Edition: 164-N-FO / 05
© Geobrugg AG
8590 Romanshorn,
Switzerland
Product Manual
VX/UX
Debris Flow Barriers

Product Manual VX/UX
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© Geobrugg AG, Switzerland
Purpose and organization of the manual
This product manual ensures that Geobrugg debris flow protection systems are manufactured free from
defects in accordance with the latest technology and that the range of applications is clearly defined, the
functional efficiency is given, and the installation of the system is professionally carried out and controlled.
The product manual is divided in the following sections:
 Proof of quality assurance / verification of conformity
 Classification of debris flow barrier systems
 Installation manual
 Input parameter for barrier design
No claims are made that this document is complete. The manual describes standard applications and does
not take into account project-specific parameters. Geobrugg cannot be held liable for any extra costs that
may be incurred for special cases. In case of uncertainties, please contact the manufacturer. The General
Sales Conditions of Geobrugg AG are applicable.
Responsible for the content of this manual:
Geobrugg AG
Aachstrasse 11
Postfach
CH-8590 Romanshorn / Switzerland
E-Mail [email protected]m
Romanshorn, 07.11.2016
(stamp / authorized signatures)

Product Manual VX/UX
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© Geobrugg AG, Switzerland
I Range of application
The design of debris flow protection systems is based on detailed investigations by specialized engineering
firms, particularly taking into account the following geotechnical aspects to define the range of possible
applications:
 Former debris flow events
 Catchment area (condition of soil, inclination, size)
 Estimated rainfall intensity
 Debris flow input parameter (volume of decisive surge and total volume, density, middle front velocity)
 Composition of debris flow (debris fraction, water content, density)
 Probability of occurrence
 Calculation of decisive load cases
 Barrier location (Consideration of local topography)
 Anchorage conditions
II Quality of the system components
Geobrugg AG is certified under the registration no. 34372 in accordance with the Quality Management
Systems Requirements (ISO 9001: 2015). The certifying body is the Swiss Association for Quality and
Management Systems (SQS), which belongs to IQNet. The quality manual completely specifies how to test
the system components (raw material, commercial and end products) comprehensively in order to exclude
deficiencies in quality. The relevant certificates are attached as appendices.
III Functional efficiency of the barrier systems
The functional efficiency of the system is based on one-to-one field tests at the Illgraben test site (Canton
VS, Switzerland). The tested barriers could retain a volume of 700 m3 in 2005 and 1'000 m3 in 2006 and
were overtopped with several debris flows with more than 10.000 m3 of material. Important input parameters
could be measured like debris flow velocity, density, flow height and impact forces and helped to develop
a full design concept.
IV Quality control for installation
This product manual describes in detail the different steps for installation of the barriers. These steps must
be faithfully followed by local building contractors.

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© Geobrugg AG, Switzerland
V Product liability
Rockfall, landslides, debris flows or avalanches are sporadic and unpredictable. The cause is human (build-
ings, etc.), for example, or forces beyond human control (weather, earthquakes, etc.). The multiplicity of
factors that may trigger such events means that guaranteeing the safety of persons and property is not an
exact science.
However, the risks of injury and loss of property can be substantially reduced by appropriate calculations
that apply good engineering practices, and by using predictable parameters along with the corresponding
implementation of flawless protective measures in identified risk areas.
Monitoring and maintenance of such systems are an absolute requirement to ensure the desired safety
level. System safety can also be diminished through events, natural disasters, inadequate dimensioning or
failure to use standard components, systems and original parts, but also through corrosion (caused by
environmental pollution or other man-made factors as well as other external influences).
In contrast to the one-to-one rockfall tests, which indeed test an extreme load case but still only demonstrate
a standardized situation, in the field the layout and design of a protection system can vary greatly because
of the topography. The influence of such alterations and adaptations cannot always be determined exactly.
Critical points are, for example, post spacing, changes in direction, placement angle of the rope anchor,
and the direction and velocity of impact.
Geobrugg can assist with estimating the influence of larger deviations and special situations, and can offer
recommendations for feasible solutions. Geobrugg cannot, however, guarantee the same behaviour as in
the one-to-one rockfall tests. In critical cases, it is advisable to reinforce particular components as compared
with the standard barrier.

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© Geobrugg AG, Switzerland
Contents
I Range of application ......................................................................................................................... 3
II Quality of the system components ................................................................................................. 3
III Functional efficiency of the barrier systems .................................................................................. 3
IV Quality control for installation ......................................................................................................... 3
V Product liability ................................................................................................................................. 4
1 Introduction ....................................................................................................................................... 6
1.1 Validity of installation instructions ....................................................................................................... 6
1.2 Construction ........................................................................................................................................ 6
1.3 System drawing of the rope guiding for UX/VX systems .................................................................... 9
1.4 Anchor forces .................................................................................................................................... 10
2 Installation of the barrier ................................................................................................................ 10
2.1 Installation steps for UX - barriers ..................................................................................................... 10
2.2 Recommended installation tools ....................................................................................................... 11
2.3 Use of wire rope clips ........................................................................................................................ 12
3 Anchorages ...................................................................................................................................... 14
3.1 Marking of the anchorage locations .................................................................................................. 14
3.2 Position of the anchors for the retaining ropes ................................................................................. 15
3.3 Anchorage of the post foundation ..................................................................................................... 17
3.4 Post foundation ................................................................................................................................. 18
3.5 Anchorage of the support and retaining ropes .................................................................................. 19
3.6 Arrangement of flexible heads .......................................................................................................... 20
4 Superstructure ................................................................................................................................. 21
4.1 Installation of the posts, support and retaining ropes ....................................................................... 21
4.2 Installation of the ring net .................................................................................................................. 23
4.3 Installation of the abrasion protection ............................................................................................... 25
5 Final inspection ............................................................................................................................... 26
6 Service and Maintenance ............................................................................................................... 27
6.1 Accessibility ....................................................................................................................................... 27
6.2 Regular inspection ............................................................................................................................. 27
6.3 Inspection after events ...................................................................................................................... 28
6.4 Criteria for servicing .......................................................................................................................... 28
6.5 Tools for debris flow barrier maintenance ......................................................................................... 31
6.6 Emptying and clearing out the barriers ............................................................................................. 31
7 Standard system drawings ............................................................................................................ 33
8 Input values for barrier dimensioning........................................................................................... 34
9 Maintenance form for field inspection .......................................................................................... 36

Product Manual VX/UX
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© Geobrugg AG, Switzerland
1 Introduction
1.1 Validity of installation instructions
This installation manual is valuable for Geobruggs VX/UX Systems up to a debris pressure of
180 kN/m/hfl. If the expected debris pressure is more than 180 kN/m/hfl, contact Geobrugg AG for a possi-
ble solution.
1.2 Construction
The debris flow barrier system consists of the following components:
 ROCCO®- ring net
The ROCCO ring net is the main element of the system and
consists of high-tensile wire with a tensile strength of 1770
N/mm2 and a diameter of 3 mm. Different types are used in
the debris flow systems according to their design resistance.
 Support and retaining ropes
The job of the support ropes is to transmit the forces occurring
in the net over the posts to the anchors.
 Abrasion protection
The abrasion protection protects the upper support ropes from
abrasion if the barrier is completely filled and gets overtopped.

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© Geobrugg AG, Switzerland
 Spiral rope anchor
The support and retaining ropes are anchored in the soil or
rock by means of Geobrugg spiral rope anchors.
Alternative self drilling anchors (for example Typ Titan or IBO)
can be use. The spiral rope anchors are equipped with a flex-
ible head, which ensures that forces not working directly in the
pulling direction can also be transmitted. Two galvanized
tubes over the anchor head, plus the galvanized spiral rope,
provide double corrosion protection.
 Brake rings
The task of the built-in Geobrugg brake elements (brake rings)
is to dissipate energy via plastic deformation and friction, and
to protect the support ropes from overload. The steel tubes
also protect the rope from corrosion and mechanical damage.
 Base plate
The base plates are the base for the posts and are either set
on a concrete foundation. The concrete foundation is fixed
with tension and pressure anchors in the ground of the torrent.
The posts are hinged on the plates. All elements that come in
contact with the ropes are finished without sharp edges to
avoid rope damage.
 Hinged post
The posts have the function to keep the system height after
filling the barrier. HEB type steel posts are used. The rope
guides at the post head are finished without sharp edges to
protect the ropes. The posts are held in position with the help
of retaining ropes. The order in which the ropes are arranged
on the post head corresponds to the installation sequence.

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© Geobrugg AG, Switzerland
 Shackles
The connections between the ring net and the ropes are made
with shackles. They guarantee that the net can slide on the
rope without damaging it. The nets are also connected verti-
cally with shackles. In general, the shackles are designed to
produce the stronger connection than the net itself. The
shackles can be bonded with adhesive (e.g., with Loctite) if
they are required to be theft-proof.
 Wire rope clips
The ropes are delivered with pressed loops on one side of the
rope. The free end has to be fixed with wire rope clips accord-
ing to EN 13411-5 (DIN 1142). It is very important to use the
right number of wire rope clips with the required torque values.
The wire rope clips can be bonded with adhesive (e.g., with
Loctite) if they are required to be theft-proof.

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© Geobrugg AG, Switzerland
1.3 System drawing of the rope guiding for UX/VX systems
The end of the ropes with pressed loops is fixed with shackles at the flexible head of the anchors. On the
other side the ropes will be spanned and fixed with wire rope clips. In the same way also the winglet rope
is installed. With shackles it is additional fixed to the upper support rope. The border rope is fixed to the
flexible head of the winglet rope and will be guided through every flexible head down to the lowest anchor-
age of the bottom rope and will be fixed with wire rope clips.
System drawing VX
System drawing UX
Upper support rope
Bottom support ropes
Border rope
Winglet rope
Middle support rope
Winglet rope
Middle support ropes Upper support ropes
Lower support ropes
Posts
Abrasion protection
Abrasion protection

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© Geobrugg AG, Switzerland
1.4 Anchor forces
The force caused by a debris flow can be very high. Therefore the underground engineering and installation
work has to be done precise and accurate. The length of the anchors is based on the measured rope forces
of the 1:1 field tests and depending on the quality and soil bearing capacity.
2 Installation of the barrier
2.1 Installation steps for UX - barriers
The step by step installation is divided in the following topics. The detailed steps are described in each
chapter. The manual describes the installation of UX barriers including posts. The installation of VX barriers
without posts are accordingly, without the described steps to install the posts, base plates and retaining
ropes.
Preliminary work Chapter 3
 Site preparing
 Stake out the anchor positions
Foundation construction Chapter 3
 Drilling of the anchors and injecting
 If self drilling anchors are used, the flexible heads have to be fixed to the anchors
 Construction of the post fundaments
 Place the base plates on the anchors
Construction of the superstructure Chapter 4
 Fix the upper ropes to the anchors and pull them by a chain hoist or Habegger. Same installation
approach has to be done with the winglet rope. Support ropes have not to be tensioned yet.
 Place the posts
 Tension the retaining ropes
 Tension the upper support ropes. If there are several ropes hold them together with a shackle.
 Tension the winglet ropes. The winglet ropes are fixed with shackles to the upper ropes.
 Loop and tension the border ropes
 Tension the lower ropes. If there are several ropes hold them together with a shackle.
 Clamp the ring net to the upper ropes
 Connect the net panels together with shackles
 Clamp the net to the bottom ropes with shackles
 Installation of the middle support ropes. If there are several ropes hold them together with a shackle.
 Installation of the abrasion protection with a crane, chain hoist or helicopter. It is fixed to the upper
support and the winglet ropes with the welded shackles.

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© Geobrugg AG, Switzerland
2.2 Recommended installation tools
The following tools are recommended for marking and installation
Marking
 Measuring tap 30 to 50 m
 2 meter folding rule
 Inclinometer
 Spray paint
 Wooden or iron pegs
 Hammer
 Product manual
Installation
 Open-ended or ring wrench SW 22 and 24
 Socket wrench with ratchet
 Torque wrench SW 27 and 32, range -330 Nm (required torque)
 Felco C16 or C112 or equivalent; cutting capacity 12 mm
 Motor disc cutter or hammer wire rope cutter; cutting capacity 28 mm
 Pincers, flat nose pliers
 Galvanized stranded wire binding cord
 Angle spirit level
 Roll of adhesive tape
 Draw tongs 14-26 mm
 At least tow tension belts/straps
 Come-along/pulley, e.g., type LUG-ALL®
 Chain hoist or Habegger, at least 3.5 t (35kN)
 Auxiliary ropes
Table 1: installation tools

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© Geobrugg AG, Switzerland
2.3 Use of wire rope clips
Instructions below apply to all wire rope clips according FF-C-450 type 1
class 1 (similar EN 13411-5 type 2) delivered by Geobrugg AG.
The distance e between the wire rope clips should be at least 1 x t but
not exceed 2 x t, where t is the width of the clamping jaws. The loose
rope end has to be 3 x e at a minimum. Geobrugg recommends looping
up the remaining free section and fixing it directly behind the last wire
rope clip on the tightened rope.
If you are using a thimble in the loop structure, the first wire rope clip must
be attached directly next to the thimble. For loops without a thimble the
length h between the first wire rope clip and the point of load incidence
must minimally be 15-time the nominal diameter of the rope. In unloaded
condition the length h of the loop should be not less than the double of
the loop width h/2.
The clamping brackets (U-brackets) must always be fitted to the unstressed end of the rope, the
clamping jaws (saddle) must always be fitted to the strained rope („never saddle a dead horse“).
During tightening the nuts have to be tensioned equally (alternately) until the required tightening torque is
reached.
The required tightening torques with lubrication apply to wire rope clips
whose bearing surfaces and the threads of the nuts have been greased with
Panolin CL 60 multipurpose lubricant spray (or an equivalent lubricant).
FF-C-450 type 1 class 1

Wire rope
diameter
[mm]
Size
of the
wire rope clip
Required
amount of
wire rope clips
Required
tightening
torque lubri-
cated
[Nm]
Required
tightening
torque
unlubricated
[Nm]
Wrench
size
[mm]
18 - 20 3/4‘‘ 4 90 180 27
22
GEOBINEX 7/8“ 5 150 330 32
A visible contusion of the wire ropes pos-
itively indicates that the wire rope clips
have been tightened to the required tight-
ening torque.
Wire rope clips always have to be installed and used with the required tensioning torque. It is not allowed
to re-use clips once they have been detached.
After the first load application the tightening torque has to be checked
and if not fulfilled adjusted to the required value.

3 Anchorages
3.1 Marking of the anchorage locations
The position of the debris flow barrier has to be fixed by the design engineer. Beneficial are smaller torrent
sections with stable slopes to anchor the barrier. The maximum span width should not be larger than 25 m
and the height of the barrier should not be more than 6 m. The basal opening between the lower support
ropes and the river bed should be specified by an expert according to the expected flow height of the debris
flow. The range of the basal opening normally lies between 0.5 and 1 m.
Anchorage points for the support ropes:
The angle between the winglet rope and the upper support ropes should be between 20-25°. This geometric
effect of the winglet ropes builds an overflow section. The overflow section must be smaller than the span
width of the river bed, so the erosion effect of the river banks can be minimized.
The anchors of the upper and lower support ropes should be determined that the target height of the barrier
is full filled. The middle support ropes are fixed in the middle of the section shown in the drawings. The
barrier line is normally orthogonal to the flow direction. The barrier should be sloped forward in vertical
direction max. 5°. The anchorage points have to be determined by marked points with spray paints.
Anchorage points for the retaining ropes:
The anchors of the retaining ropes have to be fixed behind the posts with an angle between 20° – 40° side
wards of the horizontal line. The posts should be inclined max. 5°. The angle bet-ween the retaining ropes
and the posts should be 60° - 85° in all cases.

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© Geobrugg AG, Switzerland
3.2 Position of the anchors for the retaining ropes
barrier post
α α
α should be between 20 - 40°
retaining ropes retaining ropes
Flow direction

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© Geobrugg AG, Switzerland
5° post inclination
60°-85°
post
retaining rope
15°

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© Geobrugg AG, Switzerland
3.3 Anchorage of the post foundation
The reinforced post foundation transfers the horizontal and vertical load from the foundation over the an-
chorage to the ground. The post foundation is anchored with one compression anchor and two tension
anchors. The compression anchor has to be drilled in vertical direction and the two tension anchors have
to be built in 45° to horizontal direction and 10° inclined to the flow direction.
To have the optimum load transfer you have to put quadratic steel plates at the end of the anchors and
have to fix them with a nut. The connection between the foundation and the base plate is done with two
shorter bars built in vertical direction. The base plate has to be installed to these bars having the elongated
holes valley site.
Installation steps:
 Dig out the foundation hole
 Drill the anchorage
 Shutter the foundation and build in the reinforcement. Put on top the anchor plates.
 Build in the two bars for the base plate (Use the base plate as a face mould)
 Concrete the foundation. Please round the foundation edges if the border rope is led along the
foundation.
 The fastening of nuts may not be tightened until the concrete has cured completely.

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© Geobrugg AG, Switzerland
3.4 Post foundation
Sectional view
Plan view
Compression anchor
(on site)
Tension anchor (on site)
minimum reinforcement 10/100 (on site)
Tension anchors
365
1000
flow direction
flow direction
200
1000
1000
1000
optional with helix reinforcement (on site)
200
45°
GEWI
D= 40mm

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© Geobrugg AG, Switzerland
3.5 Anchorage of the support and retaining ropes
The anchors of the support ropes have to be drilled in direction of the support ropes. If several anchors are
needed for several ropes at one point, please incline one anchor 15° backwards to the flow direction and
arrange it a little bit lower than the first one. The flexible anchor heads must lie as closed as possible to the
ground surface to avoid a too large distance between the border rope and the slope. The flexible anchor
heads make sure that loads not acting in the anchor line can be transmitted. So, after an event only the
superstructure has to be re-build and repaired.
Installation steps:
 Dig the foundations
 Drill the anchors
 Put the flexible heads on the anchors if self drilling anchors are used. Shutter and reinforce the
foundation. The flexible heads have to be built in up to the orange marking. The edge of the con-
crete foundation has to be rounded because of the border ropes.
 The holes of the shutter around the flexible heads have to be stuffed with polyethylene foam.
 Concrete the foundation
Reinforcement 10/100
(on site)
marking of
installation
depth

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© Geobrugg AG, Switzerland
3.6 Arrangement of flexible heads
The loading of the anchors is not in its line direction after an event. They get deformed in vertical and
horizontal direction. This means that the anchors have to be installed in this manner that they can deform
in these directions. The best way is to incline the flexible heads 45° forward so also the border ropes are
installed easily.
Correct inclined flexible heads. The inclination
should be ~ 45°.
Acting debris flow
Arrangement of
flexible heads
Debris flow barrier
45°