"Dilatation Compensation System" for different shaft covers in a surface area
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„Dilatation Compensation System“ for different shaft covers in a surface area (DI Dr. Egon Haar) Abstract: The following report reveals the possibility to solve a frequent problem occurring in road construction, the destruction of the asphalt surface in the surrounding area of shafts. Though we assume the cause, the engineering solution, the selection of the materials, the testphase and results as well as the economic consequences. The Problem: Already shortly after the completion of a street first damages in the surrounding asphalt of the driving surface occur. The damages manifest themselves mostly in initially small concentric crack forming in the asphalt around the shaft gate unit. They are getting in a short time bigger and are forming a reticulate structure, producing deformation of the road surface (fig. 1 and 2) fig. 1 fig. 2
How many shafts exist and where are they?
In reference to statistics of the „Institut für unterirdische Infrastruktur (IKT)
Gelsenkirchen“ there exist approximately 10 million shafts in Germany. Related to
Austria, on that basis it is possible to calculate with approx. 1 million shafts. The IKT
calculated, that for the refurbishment of the shafts in Germany in the next years an
investment of around 5,3 Billion Euro is to be due. For the refurbishment of the
asphalt surrounding of the shafts according to our calculation it has to be counted
with approx. 10 to 15% of that amount.
According statistical evaluations approx. 70% of the shafts are situated in streets,
thereof about 53% in municipal- and approx. 17% in rural and federal roads.
Looking to the ownership structure of the shafts, namely approx. 70% is municipal
ownership, 20% belong to waste water associations and around 10% are in the
range of other legal entities, so this means, that the major burden of the
refurbishment costs have to be beard by the communities. So there exists is a
substantial savings potential, if a technical solution can remove this problem.
Damage Statistics of different streets
Within the scope of our extensive investigations it has been ascertained, that the
damage of the road surface around the shaft not only depend of the age of the road
and the climatic circumstances, but also of the quality of construction and particularly
of the load of traffic.
Zustand der Strassenoberfläche in der Umgebung von
Abwasserkanalschächten bei verschiedenen Strassen
Defekt: Defekt + saniert: Saniert: Ganz:
100% gut
gut
80% gut
gut
60%
schlecht
schlecht
Prozent
40%
schlecht
schlecht
schlecht
20%
Stark befahrene Schwach befahrene Stark befahrene innerstädtische
Ortsdurchfahrt auch Innestädtische Straße; kaum Straße ; etwas Schwerverkehr
Schwerverkehr ( 38 t) Schwerverkehr (Bus)
0%
Daten: Dr. Haar
1 Jahr 3 Jahre 13 Jahre 13 Jahre 32 Jahre Strassenerhebung April
Jahre seit der Errichtung der Strasse 2002
fig. 3
From fig. 3 it can be seen, that roads with heavy traffic (38 t), e.g. transit of towns,
show that already after one year asphalt damages (30%) around the shafts occur.
After 3 years the picture of damage has intensified so much, that only approx. over
20% of the shaft surroundings can be identified as totally intact. Over 50% have to be
renovated. However from the renovated sites nearly 60% are already in need of
repair.
2
Lightly used streets (without heavy traffic), as like in residential areas, however show
after 13 years only about 50% of wear areas. The repair measures however do not
have a permanent result. The investigations showed, that already the bus traffic
leads to strong street damages in the mentioned area.
The consequences:
Calculations, which have been proven by statistical studies, have shown, that the
repair costs per shaft add up around 160 to 415 Euros. Included in this repair costs
are asphalt cutting, demolition, excavation work, machinery, material and working
time. The most frequent repair costs that have arisen where around 290 Euro.
Additionally to this significant damages also damages not possible to evaluate from
our side like at snowploughs and cars have to be added, but also noise, pond
building a.o.m.
Why damages occur?
The until now applied design builds an inflexible connection of shaft and street
structure (fig. 4).
Problem: Durch Senkungen und Hebungen ( z.B. durch Frost/Tauwechsel, Setzungen) in der
Umgebung des Schachtes entstehen um den starren Schacht Zugspannungen im Asphalt, die zu
Rissen führen. Durch diese Risse dringt Wasser ein, welches besonders im Winter den
Zerstörungsprozeß beschleunigt. Der Belag verliert an statischer Tragkraft.
+x
+/- 0
-x
Hebung
Risse
Senkung
Der Schacht bleibt
weitgehend starr
fig. 4
However there are relative movements occurring in the form of settlements and
enhancements between shaft and road construction.
Reason for those are given by uncontrolled compactions in the road structure (traffic)
and frost-dew changes (volume change in the area of Planum and frost zone).
3
Höhenveränderungen Europastraße
24
22
20
Höhenverä nderung (m m ) Scha chtinnente m pera tur (°C)
18
16 FROST - TAUBEWEGUNGEN bis zu 3 mm / Tag
14
12
10 Schachtinnentemperatur Höhenveränderung
8
6
4
2
0
-2
-4
-6 HÖHENVERÄNDERUNGEN DER STRASSE WERDEN VOM SYSTEM
-8 ANA ÜBERNOMMEN
-10
18.11.00
21.11.00
24.11.00
27.11.00
30.11.00
03.12.00
06.12.00
09.12.00
12.12.00
15.12.00
18.12.00
21.12.00
24.12.00
27.12.00
30.12.00
02.01.01
05.01.01
08.01.01
11.01.01
14.01.01
17.01.01
20.01.01
23.01.01
26.01.01
29.01.01
01.02.01
04.02.01
07.02.01
10.02.01
13.02.01
16.02.01
19.02.01
22.02.01
25.02.01
28.02.01
03.03.01
06.03.01
09.03.01
12.03.01
Datum
fig. 5
Test series have resulted, that frost-dew movements up to 3mm height changes can
occur per day. (fig. 5). Thereby it has been shown, that in the inside of the shaft
hardly temperatures below the freezing point occur. This can be traced back to the
fact of the waste water temperatures, which mostly lie above the freezing point.
From the road surface, being exposed to the biggest temperature changes, until the
depth of frost penetration border line in about 1,2 m of depth, height changes occur.
As reason for that as most significant factor the volume change with the change of
the aggregate condition of the water being situated in the Planum and the frost
penetrated area from fluid to solid (ice) has to be seen. The more humidity in the road
structure, the higher the height changes.
In this way the, because of the cold, brittle road cover will be stressed so far, that it
will be broken. Because of the fact, that asphalt especially with low temperatures is
delicate against tensile stress, cracks occur very often during winter time. Therewith
one of the main reasons for the damage of the asphalted shaft surrounding is proven.
Furthermore it can be stated, that with brittle asphalt cover more humidity is migrating
into Planum and frost area and therefore the destruction of the asphalt surface rather
will be increased.
Method of Resolution:
As approach for a system which should eliminate these failures, the transformation of
the inflexible into a flexible one has been determined. In doing so particularly the
vertical movements of the road surface against the shaft body have to be levelled,
which with the conventional construction is not possible.
Principal thought and first model:
As an appropriate measure for that requirement the Telescope has been included in
the analysis. For the transfer of the forces, which the Telescope needs to
compensate the vertical movements, a drag fibreboard panel has been selected,
4
which is fixed between Planum and asphalt layer. In this first design a flat drag fibre
panel has been selected as a model for calculation of the occurring tensions (fig. 6)
Lösungsansatz Schachtdeckel und
Deckelrahmen
Schlepplatte
Dilatationselement
Verschleißbelag Führungselement
und bituminöse
Tragschicht Schacht
Frostkoffer und
Planum
Untergrund zueinander
verschiebbare
Einheiten
wesentliche Vorteile gegenüber dem starren System
• Vertikale Bewegungen, Verschlußorgan immer auf Verkehrsflächenniveau;
• keine Belagschäden, kurzfristige Amortisation;
• weniger Verkehrsbelästigungen;
• Vermeidung von Schäden bei Schneeräumarbeiten;
• geringere Flächenpressung im Schachtbereich;
fig. 6
History of the development:
To check these first ideas for their possibility of implementation, a feasibility study
with the “Zentrum für angewandte Technologie in Leoben” (now a.p.e.) had been
created. In this work not only the feasibility has been investigated, but also different
draft versions based on the requirements.
The work included: concept development, engineering and simulation (fig. 7)
• Concepts and evaluation
• Basic engineering
• Versions of geometry, material and stress/wear conditions
• Simulation and optimisation of the design
• Stress analysis under different conditions
fig. 7
5
Also the material selection and –examination has been made, taking into
consideration the material wear during installation and operation. Within the scope of
material selection and –examination the production procedure, the design of the
prototypes and there installation as well as the measurement and examination of the
components have been carried out (fig. 8 and 9).
fig. 8
fig. 9
At the same time the material has to assure to have high resistance against high
temperature fluctuations (during installation approx. 190 °C asphalt temperature and
in winter time up to – 30°C occur) and chemical influences, but especially a high
harmonic stress equalisation as well as high resistance against continuous vibration
load.
GFK (glass fiber reinforced plastic) with special resins has been selected as material
for the panel, which should meet the requirements. Calculations and tests lets
suggest a product life of considerably beyond 25 years. The frame is manufactured
from a conventional GFK-tube, the membrane from commercially available rubber.
The detailed engineering has been optimised by various simulation models. The
optimisation (fig. 10) generated besides the reduction of the drag fiber panel weight
of about 50% against the first version also a change of the design. So due to the
calculation- and measuring results the drag fiber panel has been converted from a
flat into a cranked form. That makes besides the simplified installation also the
direction of the forces into respectively from the underground onto the plate in some
distance to the shaft. This zone, with conventional construction, is especially
vulnerable to compaction failures.
6
fig. 10
The drag fiber panel is connected flexible by a rubber membrane with the telescope
(new design version) respectively with the shaft (refurbishment version). This leads to
a decoupling of the shaft and the shaft closure, and brought in later following
simulation steps the definite verification of performance, which is not only limited on
round shafts, but also on application with square shafts too.
Besides the calculations and trials the system – from the first design on to the end
version – has been undergoing an intensive practical testing in a traffic simulation
with a very strong hydraulic press (80 t) (fig. 11) and over the years has been
installed in different road types with different loads (fig. 12). The results of the
practical testing show, that all expectations are totally fulfilled.
fig. 11
fig. 12
7Economical advantages of the „Dilitation Compensation System“
Comparing the effort of the conventional with the new system, it has to be observed,
that the erecting costs for the new system, in relation to the utility, are only
insignificantly higher. In the assurance, that already after a relatively short period with
the conventional system significant refurbishment costs are applying, which mostly
recur, it can be calculated in the middle- and long term, that the effort for the old
system exceeds those of the new system significant.
We therefore have, to evaluate with high safety the economical difference of both
systems, created a model, which on the one hand revert on secured data and on the
other hand takes a conservative aproach. The result of those calculations is
displayed in fig. 13.
Effort Comparison for the new Dilitation- and conventional
system over a time period of 30 years (for a shaft).
Aufwandsvergleich für das ANA- und das
herkömmliche System über einen Zeitraum von
30 Jahren (für einen Schacht).
2520
Repararturaufwendungen pro Schacht in EURO
Start mit der Erstherstellung
Sanierungsabstand jedes 4. Jahr 6.
2160 Das bedeutet, daß im Beobachtungszeitraum
von 30 Jahren, rechnerisch, jeder Schacht 5.
einmal saniert werden muß
1800
4.
1440 Sanierungsaufwendungen min/max 3.
1080 2.
minimale Lebenszeit
720 für das
Sanierung 1. ANA-System
360
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Jahre
Nach anfänglichen Mehrkosten ist schon nach 4 bis 5 Jahren das ANA-System
billiger. Dieser Kostenvorteil steigert sich mit der Zeit noch deutlich
fig. 13
It is to see from, that already after the first repair of the conventional system the initial
additional costs of the “dilatation compensation system” will be exceeded. This
proceeds with an estimated life time of the street of 25 years and raises up to the six-
till ten times of additional expenses.
To make it easier for communities, to bear the initially slightly higher costs, a
financing plan can be offered. Thereby with the savings achieved against the
conventional system the cost of the “dilatation compensation system” will be payed,
giving way to ownership of the community of the system after only six years. In that
way every property developer can use the advantage of a technically and
strategically beneficial system. The project for the realisation of the dilatation system
has also been supported by the “Forschungs-Förderungs-Fonds der österreichischen
8Bundesregierung”. 1998 this new product development has been applied for a patent
and the international patent has been granted 2002.
With 01.02.2002 the serial production of the “dilatation compensation system” has
started (fig. 14)
Abbildung 14
At IFAT in Munich, the biggest international exhibition for environment and disposal,
the “dilatation compensation system” has been presented the first time to the
international public. Thereby it affected interest not only on the European continent,
but also from the US, Canada, Australia, Hong Kong and Israel reached us requests
for cooperation.
At EUREKA, the world exhibition for innovation, research and new technologies in
Brussels, the inventors of the “dilatation compensation system”, among over 600
exhibitors, have been awarded with the “Grand Prix de Innovation 2002”, the gold
medal for inventors as well as with the Belgian Inventors Decoration. In Austria the
“dilatation compensation system” is installed in various new road constructions and
refurbishment projects and has already overcome the climate- and traffic influences
over several years with full satisfaction.
Actually the following assembling systems are offered:
• Telescope with plate – round shaft - as refurbishment
• Telescope with plate – square shaft – as refurbishment
• Plate with dilatation element – round shaft – as refurbishment
• Plate directly on square shaft
• Telescope with plate –round shaft - as new construction
The development will be extended in the future also for cap locks.
Judenburg, April 2007
Register:
Institut für unterirdische Infrastruktur Gelsenkirchen; Newsletter 2001
Dipl.-Ing. R. Haffelner; Dipl.-Ing. Dr.mont. B. Mlekusch ; ape –advanced polymer
engeneering; Kunststofftechnik im Verkehrswegebau; Dilatationsssystem für
Kanalschächte
und Schachtdeckel; VKL-NEWS , Zeitschrift des Verbandes Leobner
Kunststofftechniker 2/2002, Seite 6ff
Ing. Ernst Hackenberg; Dipl.-Ing. R. Hafellner; Dipl.-Ing. Dr.mont. B. Mlekusch, Dipl.-
Ing. Dr.mont. E. Haar; Präsentations CD für das ANA-System; Version Mai 2002
9Ing. G. Ledineg; Faszl Kunststoffindustrie Ges.m.b.H.; Produktinformation ANA , Mai
2002
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