gravity retaining wall system large applications garden architecture · pdf filevibro-pressed...

v ibro -pr essed concrete b lock system

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gravity retaining wall systemlarge applicationsgarden architecture

GRAVITY STONE®

GRAVITY STONE® - large applications

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The GRAVITY STONE® system has been designed for construction of gravity retaining walls. The system is composed of several concrete blocks that

may be combined in many retaining wall variants. Block joints are dry: blocks in a single course are lock-joined, while two neighbouring courses are

connected by plastic pins. The inner space of the wall is filled by a suitable fill material. The blocks of the system are made on production facilities

purchased in the USA, by vibro-pressing technology with low water coefficient. High concrete strength may be achieved thanks to the above technology.

Building retaining walls of the GRAVITY STONE® system is quick and easy. The GRAVITY STONE® system is used for building retaining walls especially

in the below areas:

• roads• railroads• road and railroad bridges• field engineering in applications of structural engineering• adaptation and regulation of water courses• garden architecture

Introduction

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Benefits of the GRAVITY STONE® systemAesthetics

Universality

Type of construction

Assembly

Service life

Price

Retaining walls made of the GRAVITY STONE® system show high

aesthetic value. Different colours of blocks as well as different surface

finishing options of the facing block may be selected when designing the

wall. Smooth surface or split facing blocks are available as well as seven

basic colour options. The individual blocks allow for different wall shapes

as regards ground plan (curved, bent walls, etc.) as well as vertical

configuration. The main aesthetical benefit of the walls is seen in breaking

up large monotonous areas into smaller and better perceived surfaces.

The GRAVITY STONE® retaining wall system will adapt itself to any

ground plan layout. The walls may be straight, waved, convex or

concave, or bent into inner angles or outer angles. This universality

enables the designer to adapt walls in variants following the terrain,

different height configurations, etc. Gravity walls make possible the

construction of auxiliary structures like terrain steps and ramps as well

varying wall height in case of varying terrain slope. The system also

makes it possible to easily respond to actual conditions at realisation –

e.g. it is possible to easily avoid large rocks, protect trees, etc. GRAVITY

STONE® walls may be designed as modular (e.g. made of blocks only),

or reinforced (the soil behind the wall being reinforced by geogrid).

Modular walls are suitable for heights up to 6 meters and soils with high

strength, e.g. rocky ones. Reinforced walls may be efficiently designed

for soils of lower quality or in cases of exposure to high dynamic loads.

Mortar less dry joints of the GRAVITY STONE® system have multiple

advantages over the more rigid mortar joints of classic retaining walls.

The structures utilising dry assembly provide for relative shift among the

individual blocks caused by uneven settlement, different load exposure

and different influences. The nature of dry joints excludes aesthetically

adverse cracks in bed joints and side joints known from classic, especially

plastered walls. Water is freely pressed out in front of the wall through

dry bed joints, thus reducing hydrostatic pressure behind the wall.

A retaining wall of GRAVITY STONE® blocks is not difficult to assemble.

It consists of several easy, repeated tasks that do not require qualified or

professionally trained personnel. A moderate set of equipment is

necessary for assembly. On the other hand, the assembly instructions as

prescribed guarantee maximum achievable quality. Optimum productivity

may be achieved already with moderate experience, especially

represented by building a few structures. Professional training in building

retaining walls may be requested from KB-BLOK if necessary.

GRAVITY STONE® blocks are made of high-strength concrete with low

water coefficient. If a GRAVITY STONE® system retaining wall is located

in a typical environment, its quality does not deteriorate during the

entire expected service life, i.e. 100 years. Service life of the other

components of the wall like gravel fill, polymer geogrids and plastic pins

is also very long.

The investment cost of a retaining wall of the GRAVITY STONE® system

is comparable to other masonry systems and at the same time,

significantly lower than the investment cost of a concrete wall.

The maintenance cost is minimum due to service life of concrete and

long lasting aesthetics of the wall.


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Cross section view of a modular wall Cross section view of a reinforced wall

Geologic survey

Preliminary wall designThe suitable wall type must be decided upon within the preliminary wall

design. GRAVITY STONE® system walls may be divided into two groups:

modular and reinforced.

Modular walls are made of GRAVITY STONE® blocks only. The

inner space of the wall is filled with fill material. The walls do not

require as much horizontal space as reinforced walls. They are

appropriate for situations, where wall space as wall as access of

machinery is limited (e.g. in gaps, inaccessible terrain, etc.). Modular

walls are appropriate for high quality soils. They are usually designed

for lower heights than reinforced walls. A dug-in modular wall is

economically more efficient than a fill-in wall.

Reinforced walls use geogrids to reinforce the soil behind

the wall. The requirements of the walls for material and labour are

minimal. A soil of lower quality, which is usually cheaper as well, may

be used to build the wall (in the space between geogrids). Reinforced

walls may be designed for greater heights than modular walls. A fill-in

reinforced wall is economically more efficient than a dug-in wall.

Fac

ing

bloc

k

Wall anchoring

Fac

ing

bloc

k

Geogrids

Prior to commencement of the construction, a geologic survey must be

made the scope and cost of which must correspond with the size and

complexity of the construction. It is not recommended to commence the

project and the construction itself without geologic survey.

The GRAVITY STONE® wall system consists of compatible elements that

may be used in different combinations, thus offering different solutions

of retaining walls. The designer should familiarise themselves with the

simple system in order to be able to make full use of its universality.

The concrete elements of the GRAVITY STONE® system are made by

vibro-pressed technology on production facilities purchased in the USA.

This technology is based on a very low water coefficient. The

production technology, consistence of the concrete mix and use of

high-strength concrete make it possible to shape a special system of

interlocking grooves and tongues. In short, the connection is called a

lock-joint. The lock-joint connects the individual elements of the system

and provides for compatibility as well as a firm joint between the

individual system elements.

Concrete elements of the system

Construction of the GRAVITY STONE® system

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Facing blockThe facing block may be made in seven basic colours and the following

surface finish options: smooth surface and split block. It is used as a

front face block in both modular walls (made of blocks only) and

reinforced walls (by geogrids). The approximate weight of the block is

33 kg.

Anchoring dowelThe anchoring dowel connects the facing block and the anchoring

element, thus creating the necessary structural depth of a single

anchor. The dowel is made in natural colour only. The approximate

weight of the block is 24.5 kg.

Anchoring elementThe two functions of the anchoring element include anchoring itself

and providing for connection of another anchoring dowel for additional

anchoring. The block is made in natural colour only. The approximate

weight of the block is 13 kg.

Special facing block 400The block is used instead of the facing block in the situations, where a

fence adjoins to the retaining wall. The length of the block is 400 mm,

which is identical to the fence block. The block is made in seven basic

colours and the following surface finish options: smooth surface and

split block. The approximate weight of the block is 21 kg.

Facing block 95

Cap blockThe cap block is used for all wall configurations and it is available in

seven basic colours and the following surface finish options: smooth

surface and split block. The block is used for capping the last course

of facing blocks. The approximate weight of the block is 25.5 kg.

Straight cap blockThe straight cap block is used for all wall configurations and it is available

in seven basic colours and the following surface finish options: smooth

surface and split block. The block is used for capping the last course of

facing blocks. The approximate weight of the block is 13.5 kg.

Connecting pins2 pcs per facing block

Geogrids are used in the structures of reinforced retaining walls or

reinforced slopes. The main function of geogrids is to take the tension

originated in the ground structure of a retaining wall or a slope.

Geogrids are inserted in dry bed joints between concrete blocks and

fixed to them by plastic pins. The length of geogrids, their distance and

type are determined by static calculation.

The following three types of geogrids are currently used the most

frequently: KB-grid, Tensar and Miragrid.

Geogrids

The block is made in seven basic colours and the following surface

finish options: smooth surface and split block. Its function is to provide

for aesthetic layout of the wall in the form of horizontal stripes in

different colours and textures. The approximate weight of the block is

21.5 kg.


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four anchors five anchors

Anchoring principle of the GRAVITY STONE® systemThe individual elements of the system are interconnected into different

anchoring configurations in order to provide for the required weight of

the gravity retaining wall. The connection is of the grove and tongue

type moulded in each block. This is a quick and easy connection that

does not require any tools, mortar or bonding agent. The three basic

anchor configurations are the following:

two anchors three anchors

Single anchorThis configuration consists of a facing block, an anchoring dowel

and an anchoring element. The overall width of the configuration is

970 mm.

Mini anchorThis configuration consists of a facing block and two anchoring

elements. The overall width of the configuration is 720 mm.

Multiple anchorThe configuration consists of a facing block and multiple use of an

anchoring dowel and an anchoring element.

Overall width of configuration:

two anchors 1640 mm

three anchors 2310 mm

four anchors 2980 mm

five anchors 3650 mm

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Assembly and filling of GRAVITY STONE® wallsGRAVITY STONE® walls are built by dry assembly, which is easier and

faster than construction of traditional walls using mortar. Wall assembly

is easy and it may be done even by non-qualified personnel under

supervision of an experienced and trained foreman.

Connecting pinsEach facing block, special facing block 400 and facing block 95 has

two T-shaped openings on the top side. Plastic connecting pins are

inserted into the openings as shown in the picture. The pins are

inserted perpendicularly to the face of the block, into the stem of the

T-shaped opening. The pins are used to connect two blocks above each

other, to level the wall and to easily and precisely install the next course

of blocks. The pins may be installed as follows depending on the

desired configuration:

• plug of the pin forward: blocks are precisely flush above each other;

block courses are not offset; the wall is vertical

• plug of the pin backward: each course is offset by 15 mm, which

results in wall inclination from vertical by 4.3°

Note: Connecting pins are installed in the blocks before the latter are

filled.

Possibilities of installing plastic pins

Wall bondAll blocks of the GRAVITY STONE® system are running bonded, i.e. the

upper block is offset sideways by a half of its width against the lower

block as shown in the picture.

Side joints between adjacent blocks needn’t be absolutely flush in the

vertical direction, but the may be slightly deviated. We recommend

following the instructions provided in the technical section of GRAVITY

STONE® when constructing the wall.

Installation of individual courses

Connection of geogridGeogrids are connected to reinforced walls as shown in the picture.

The geogrid must be trimmed for walls curved in horizontal plan.

Assembly clip

Fixing of geogrids


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2nd layer1st layer

Bond of a wall of an inner corner with a single anchor

Reinforcement direction

Rei

nfor

cem

ent d

irect

ion

Extension of a geogrid in the next reinforcement level

Geogrid extension in the actual reinforcement level

Ext

ensi

on o

ver

the

wal

l fac

e

Inner corner reinforced by geogrids

Inner cornersThe corner bond is crucial when constructing inner corners. The figure

shows an example of an inner corner with a single anchor.

Inner corners with geogrids are reinforced so that one of the geogrids

is positioned in the distance of H/4 behind the face of the perpendicular

wall and the other geogrid is positioned to the face of the perpendicular

wall. The position of the geogrids is altered in the next level of

reinforcement, so the geogrid that overlapped over the face of the

perpendicular wall will be flush with the wall and the geogrid that was

flush with the perpendicular wall will overlap the wall face by H/4. The

figure shows a diagram of an inner corner reinforced by geogrids.

Outer cornersOuter corners are bonded identically to inner corners. An example of

a bond of an outer corner is provided by the figure. Two atypical

elements are used in the bond of every course:

• cut facing block – the overall length of the facing block is cut from

450 mm to 420 mm, i.e. by 30 mm

• KB 5-21 B block – corner split block of the horizontal dimensions of

395x195 mm. A side joint of 5 mm will result between the corner

split block and the cut facing block. In case the surface of the wall is

not split (e.g. the underground portion of the wall), a separable

smooth KB 1-20 A block will be used instead of KB 5-21 B.

KB 5-21 B block

KB 5-21 B block

Cut facing block

2nd layer1st layer

Cut facing block

Bond of a wall of an outer corner with a single anchor

Right angle bent wallsThe GRAVITY STONE® system also makes it possible to build walls bent

in right angle. Construction of such angles requires proceeding in

accordance with the following recommendations regarding the correct

structure and the aesthetic layout of inner and outer corners.

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Outer corners with geogrids are reinforced so that there is always just

one geogrid in the bed joint. This means that the geogrid that overlaps

with the perpendicular geogrid in the corner should be positioned in

the next bed joint. The figure shows a diagram of an outer corner

reinforced by geogrids.

Note: It is recommended to construct vertical curvatures and wall

corners, i.e. with no offset of blocks in the individual courses and

founded on a level gravel cushion.

Geogrid in 1st reinforcement direction reaches as far as the end of the wall

1st r

einf

orce

men

t dire

ctio

n

2nd reinforcement direction

Geo

grid

in 2

nd r

einf

orce

men

t dire

ctio

n to

be

posi

tione

d in

this

ext

ent

in th

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xt b

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int

Outer corner reinforced by geogrids

Curved walls and archesThere may be concave (or inner), or convex (or outer) curved walls.

Foundation of a curved wall requires a broader gravel cushion than

a straight wall.

Concave wallsThe minimum radius of a concave wall is given by the angle of taper

of the front section of the sides of the facing blocks. The angle is

approximately 8°, which means the minimum radius is approximately

1.5 m.

Taper angle of the front section of facing blocks and maximum angle

of rotation of adjacent blocks

Minimum radius of a concave wall Perpendicular wall connection by a concave arch

An example of a concave wall with geogrids


Trim geogrids in the curvature

Auxiliarygeogrid

Maingeogrid

Rei

nfor

cem

ent

dire

ctio

n


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Convex wallsThe minimum radius of a convex wall is given by the angle of taper of

the rear section of the sides of the facing blocks. The angle is

approximately 8.5°. This means the minimum radius is approximately

1.5 m. With convex walls, some anchoring dowels and elements must

be left out and some lock joints must be removed in some cases.

Taper angle of the rear section of facing blocks and maximum angle

of rotation of adjacent blocksMinimum radius of a convex wall

Perpendicular wall connection by a convex curvatureAn example of a convex wall with geogrids

Overlapping geogrids to be separated by soil of 80 mm thickness, at least


Rei

nfor

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ent

dire

ctio

n

Additionalinformationis available in the brochures or on the CD:

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The process of building a wall:

Compacting the gravel pad

Compacting the block fill using a vibration plate Fixing geogrid to pins

Installation of the first course

Preparation of the face for installation of the following courses

Front wall prior to installation of geogrid

Spreading the geogrid

Make an excavation or a dig in the slope at the location of

construction of a retaining wall. Lay down and properly

compact the gravel pad used as the wall foundation. Install a

drainage pipe in the lowest point of the gravel pad. A vibration

plate is used for compaction the gravel pad – see figure. The

compacting is done by three passes over the surface of the

pad. Check whether the upper face of the gravel pad is level

before installing the first course of blocks.

The first course of blocks is installed on the gravel pad. Their

horizontal position is ensured by stakes and a string, while

vertical position is checked by bubble. Each block is installed in

the proper horizontal position and aligned vertically with the

adjacent blocks. A rubber mallet is used for alignment.

Install the anchoring elements. Check their position by a stake,

a string and a bubble. Connect the facing blocks and the

anchoring elements by inserting anchoring dowels. Repeat the

process in case of multiple anchoring.

Insert plastic pins in the openings in the facing blocks. Fill the

space between anchoring elements and cavities of the facing

blocks with gravel fill. Compact the fill using a vibration plate.

1

2

3

4


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Reinforced wall may be compacted by a vibration plate or

vibration roller behind the last anchoring element

Wall capping General view

Fixing geogrid to the ground by a hook

Gravel fill prior to installation of the following courses of GRAVITY

STONE®

Course bond detail

Wall face

Preparation of the upper face of the blocks for the next course

Clean the surface of concrete blocks and continue by installing

the next course. Install facing blocks on the plastic pins. Follow

items 3 to 5 when installing the following courses.

When using geogrids, follow the below recommendations:

Surface of blocks must be cleaned prior to geogrid installation.

Geogrid roll should be laid on GRAVITY STONE® blocks and

rolled out to the back, i.e. perpendicularly to the wall face.

Reinforcement by geogrids should be continuous and cover the

entire area; non-reinforced areas are not acceptable. Geogrids

must cover 100% of the area.

Exact procedure of installation of geogrids is described in the

GRAVITY STONE® Technical Section, chapter 4.6.

The wall may be finished in cap blocks installed on the

connecting pins or bonded by a frost resistant adhesive.

5

6

7

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GRAVITY STONE® retaining wall system

… a professional tool in your hands.


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GRAVITY STONE® - garden architecture

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GRAVITY STONE® retaining wall system – garden architecturePeople have always dreamt of nice gardens.

You can make the dream come true using our GRAVITY STONE® retaining wall system.

A terrace or a retaining wall will add a touch of plasticity and beauty to your garden,

turning it into your pride.

Building a retaining wall is a child’s play and you needn’t be a pro to do it thanks to

the lock-joint system.

And the result will exceed your expectations.

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Make an excavation or a dig in the slope at the location of

construction of a retaining wall. Lay down and properly compact the

gravel pad used as the wall foundation. Install a drainage pipe in the

lowest point of the gravel pad.

Lay the first course of facing blocks. Their horizontal position is

insured by stakes and a string, while vertical position is checked by

bubble. A rubber mallet is used for alignment of the blocks.

Lay the anchoring elements. Check their position by a stake, a string

and a bubble Connect the facing blocks and anchoring elements by

inserting anchoring dowels. Repeat the process in case of multiple

anchoring.

Insert plastic pins in the opening in the facing flocks. Fill the space

between anchoring elements and cavities of the facing blocks with

gravel fill. Compact the fill using a vibration plate.

Clean the surface of concrete blocks and continue by installing the

next course. Install facing blocks on the plastic pins on the running

bond. Follow items 3 to 5 when installing the following courses.

The wall may be finished in cap blocks installed on the connecting

pins or bonded by frost resistant adhesive.

1

2

3

4

5

6

Additional information is available in the brochures:

Instruction for construction


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MINI ANCHOR

SINGLE ANCHOR

TWO ANCHORS

DRAINAGE PIPE

GEOTEXTILE FILTR non-mandatory

DRAINAGE TROUGH

TO

TAL

WA

LL H

EIG

HT

WA

LL H

EIG

HT

AB

OV

E G

RO

UN

D

GRAVEL PAD

GRAVITY STONE® system enables to build walls curved in inside arches

in practically every radius in outside arches in radius 1.5 m and also

inside and outside corners. You should use KB 5-21B bocks for

creating outside corner and a little cut the facing block GRAVITY

STONE®.

Axonometric view of the wall

Typical wall cross section

GRAVITY STONE® wall constructionGRAVITY STONE® construction system for retaining walls comes from

USA. Individual blocks of the system are made by unique technology.

This system enables to build massive gravity retaining walls with very

high static stability. Individual blocks of the system are connected by

specially shaped concrete lock. The space between the blocks is filled

by gravel fill which make together one structural element with the

concrete skeleton. Stability of the wall is ensured by gravity action of

the wall. The wall can be made in many colour variants which gives it

interesting look especially in gardens.

If height the designed wall is less then 1 m the wall can be build only

from facing elements.

Anchoring by anchoring elements and anchoring dowels allocate for

higher walls.

Walls are based on well compacted gravel pad which make a level for

the first course of the blocks. A drainage pipe is laid in the lowest point

of the gravel pad. The drainage pipe together with gravel pad should

lead away any water. This drainage system is very important for every

wall. Installation of the wall is course after course by running bond.

Gravel fill between concrete blocks are compacted after every course

of concrete masonry.

Facing blocks have width 450 mm and can be used for wall face. Those

blocks can be combined with the low blocks high 95 mm. This block

doesn’t have concrete lock. You can also choose block width 400 mm

which is especially suitable for structure a fence connected with

retaining walls. Facing blocks 95 can be used separately for

construction of little walls.

Facing block

Anchoring dowel

Anchoring element

Special facing block 400

cap block

facing block 95

facingblock

inside arch outside arch outside corner

Cut facing blockinsidecorner 90º

Blocks composition

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GRAVITY STONE®

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Split facing blockdimensions: 300 x 190 x 450 mm

weight: 34.5 kg

colour: natural, colour, white, colors 08

Smooth facing block

dimensions: 295 x 190 x 450 mm

weight: 33.0 kg


Special facing block 400dimensions: 145 x 190 x 400 mm

weight: cca 21.0 kg


Facing block 95


weight: 21.5 kg


Anchoring doweldimensions: 90 x 190 x 600 mm

weight: 24.5 kg

colour: natural

Anchoring element


weight: 13.0 kg

colour: natural

Cap blockdimensions: 300 x 95 x 450 mm

weight: 25.5 kg


Cap block straight


weight: 13.5 kg


GRAVITY STONE connecting pins

2 pcs per facing block

Technical information

Geogridtensile strength: longitudinally 65 kN*m-1

transversely 25 kN*m-1

mesh size: 22 x 30 mm

surface weight: 305 g*m-2

roll width: 3.6 m

roll length: 100 m

We can supply other types of geogrids upon request or send a complex offer of geogrids for calculation of a retaining wall.

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With the respect to cement basis of the products the products can not be complain of efflorescence.

With the respect to cement basis of the products the products can not be complain of efflorescence.

Colour options – split surface

Natural Red Brown

Black Yellow Cinnamon

White

Colour options – smooth surface

Natural Red Brown

Black Yellow Cinnamon

White

Basic colours

Colour options COLORS 08 – split surface

Range of colours

Colour options COLORS 08 – smooth surface

Natural White BC Roman Yellow BC Sand BC

Vanilla BC Apricot BC Pink BC

Natural White BC Roman Yellow BC Sand BC

Vanilla BC Apricot BC Pink BC

INNOVATION!

general information

KB blocks

KB KLASIK blocks

KB ATLAS blocks

covering blocks

retaining walls

garden architecture

pavement

GRIND blocks

equipment

roof covering

technical section

price list and the rest

vibro-pressed concreteblock system

www.kb -b lok .cz

KB

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KB-BLOK systém, s.r.o.ul. Masarykova čp. 635, 439 42 Postoloprty – průmyslová zóna

Trade division Postoloprty - Czech RepublicReception: +420 415 778 311Technical department: +420 415 778 316Orders: +420 415 778 317, +420 415 778 318

+420 415 778 319, +420 415 778 385Transport: +420 415 778 320Expedition: +420 415 778 321Fax for orders: +420 415 783 397GSM: +420 736 629 576, +420 736 629 572e-mail: [email protected]

Eng. Marcela VITOVA, PhDstructural engineerAdamovska 1/803140 00 Praha 4Czech Republictel./fax.: +420 261 215 159mobile: +420 603 759 601e-mail: [email protected]

gravity retaining wall system large applications garden architecture · pdf filevibro-pressed...

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