Land Subsidence (Proceedings of the Fourth International Symposium on Land
Subsidence, May 1991). IAHS Publ. no. 200,1991.
Engineering and Environmental Impacts Caused by Land
Subsidence Due to Subsurface Extraction of Solid Raw
Materials from Poland
J. LISZKOWSKI
Institute of Geology, Department of Geographical and Geological Sciences, Adam Mickiewicz's
University, Poznan, Poland
ABSTRACT Poland is a country of intensive and
extensive mining activities for coal, zink,
lead and copper ores, native sulphur and salts.
However, the principal mineral mined is and has
been for more than 200 years, coal. Collapse
of underground working results in ground-surface subsidence, both continous and discontinous. The paper present the most new data
concerning the mechanisms, areal distribution,
amplitudes, rates and hazards of mining subsidence from Poland.
INTRODUCTION
Land subsidence is a common exogeodynamic phenomenon in
Poland. Both natural and man-made (anthropogenic) categories of land subsidence are known. The last category is of
special interest from the standpoint of engineering geology
since it. is much more hazardous for life and property.
Table 1 list the main types of anthropogenic subsidence in
terms of geologic processes and man's activities as known
from Poland. The individual types of anthropogenic land
subsidence listed differ in their sources of ground surface
level disequilibrium, physical nature and kinematics and
these characteristics are qualitatively summarized in
Table 1 too.
Anthropogenic subsidence is in general - with few
exceptions only - of one to three orders faster than natural one. Thus it is well justified to speak from accelerated subsidence in the case of man-made one.
Only one type of accelerated land subsidence from
Poland will be discussed below, namely: subsidence due to
subterranean extraction of solid raw materials. Other types
of anthropogenic subsidence where described elsewhere
(Liszkowski, 1989).
THE DISTRIBUTION OF ANTHROPOGENIC LAND SUBSIDENCE IN
POLAND
Although the main objectives of the paper will be subsidence due to subsurface mining of solids, it seems to;
/. Liszkowski
370
TABLE 1 Types of anthropogenic /accelerated/ land
subsidence as known from Poland.
Ko.
Type of ground-surface
subsidence
1
Accelerated subterranean
erosion
2 Accelerated hydrocompaction
3 Excessive withdrawal
of groundwater
3a - for water supply
3b - in pre-mining drainage
4
Drainage of organic
deposits
5
Subsurface extraction of
solids by:
- mining
5a
5b - brining /solution/
5oo - melting-out
Sources of subsidence
Physical nature of
ground surface
subsidence
mass loss
continuous &
discontinuous
continuous S
discontinuous
yield strength
reduction
relative increase
of vertical
stresses /consolidation/
compaction /consolidation/ 8» biochemical degradation
mass losst
relative increase of
vertical stresses
yield strength
reduction
continuous
continuous &
discontinuous
continuous &
discontinuous
continuous S
discontinuous
discontinuous
discontinuous
Kinematics
slow & rapid
rapid
slow
slow
rapid
rapid
rapid
rapid
be of interest to discuss shortly the collocation of
various types of accelerated subsidence in Poland. Pig. 1
is a simplified graphic representation of accelerated land
subsidence occurences in Poland.
It can be seen from Pig. 1 that as a rule land subsidence is strongly localized and coincide either with
large urban-industrial complexes (Warsaw, Lodz, Gdansk,
Szczecin, Poznan) and the location of major open-pit mines
of brown coal, sulphur and some earth material resources,
e.g. aggregates (assigned H. on Pig. 1), either with the
location of intensively exploited major subterranean mineral resources (assigned ff on Pig. 1) or with areas of
intensive drainage of organic deposits (assigned T on Pig.
1).
Subsidence due to heavy extraction of ground-water for
different uses is usually extensive but rather slow (rates
of subsidence
< 0.01 m/y) and may pass unnoticed without the use of precise geodetic techniques. However,
intensive extraction of solids by mining techniques and
drainage of organic deposits is more localized and rapid
(rates of subsidence > 0„01 m/y)* There is one area in
Poland where subsidence is both extensive and fasts
this
is the case of the Upper Silesian Coal Basin (USCff), heavily mined for coal and zinc and lead ores for more than two
hundred years. Here individual subsidence lows overlap
together to form complex subregional subsidence troughs
of more than 10° - 101 km^ area.
SOME REMARKS ON THE MECHANISMS OP MINING SUBSIDENCE
The geometric and kinematic characteristics of mining subsidence are in part dependent on the extraction technologies and techniques used. Actually the following extraction
371
Engineering and environmental impacts caused by land subsidence
Çj
Kfkm2
Q
102km*
O
O
10'km2
105m2
V
Y\__~
> \ te
Katowicç
O
o
10 3 m z
10 ! m 2
1 V2
S3
0
40
t
mi
80
120
i.
i
160km
I
PIG. 1 Distribution of anthropogenic land-subsidence in Poland.
1 - area affected by land subsidence due to:
G- - mining, H - excessive extraction of ground
water, T - drainage of organic deposits;
2 discontinnous subsidence and collapsesj 3 some more known sites of residentional building failures; s - due to accelerated piping
and hydrocompaction.
technologies are used in Poland: mining; controlled and
bastard brining and subsurface melting-out. The most common extraction technology used is mining.
Three mining techniques are put into operation: pillar
and stall working, a partial extraction mining method used
for extraction of copper, zinc and lead, ironstones
(now
ceased) and salt; vein stoping in the case of steeply
dipping ore or other mineral veins or lodes (e.g. baryte
in the Sudetes) and longwall mining, a full extraction
mining method used for pit-coal mining. In the 19th
and
the early 20th centuries bell pits were a common used mining method for coal, ironstones, clays and building stones.
Controlled brining- was used only in the: salt-mine at Inowrociaw but after a heavy catastrophic subsidence disaster
in the Wapno> salt mine, this practice has ceased. Bastard
/. Liszkowski
372
mining is practised in the Wielician and Bochnia salt
mines. And at all subsurface melting-out technique is used
for the extraction of native sulphur in the Grzybow and
Jeziorko areas, • Carpathian Foredeep, Southern Poland.
Pull extraction mining method usually result in complete (flat-bottomed), continuous subsidence depressions;
all other extraction technologies result either in incom plete (concave-bottomed)j regular or irregular, continuous
subsidence depressions or linear and or isometric discontinuous subsidences, often of catastrophic rate of groundsurface displacement (collapses),
The mining cavities represent strain nuclei. The strains migrate from the roof of the- mining cavities towards
the ground-surface with strain rates depending on the
stresses created, which depend itself on the dimensions of
the cavities - and the rheological behaviour of the rock
masses immediately above the void roof ("direct roof"
material). The final result of this strain migration
process is the ground-surface subsidence. It is clear that
the radius of subsidence will be a function of depth of
the strain nucleus since "limit angles:" and "angles^ of
break" have finite values.. As.: rock and rock mass properties vary from one mining area to; another, no general and
closed physical formulations of the subsidence mechanisms
are at present known. However, for a given mining area the:
variability of material properties may be assumed as constant. Then empirical and exact solutions, based on different approaches to the problem, may be obtained and are
widespread used for predictive purposes (H.M.S.O., 1949;
National Goal Board, 1966; Kratzsch, 1974; Surface ...,
1980).
If the amount of subsidence (s max) and the.' radius of
influence (r) are known, either from' measurements or calculations, all other geometric, physical and kinematicparameters of subsidence may be predicted. The forecasting
equations used in Poland (Pig. 2) are based on Budryk Knothe's and Kochmanski's theories which are successful
used in the- USCB for more than 35 years,. However, both
s max and r may be calculated using following: empirical
equations:
or
s max = a » dc
(1)
r = z • cot/?
(2)
r = E d i . cot^
(2»)
where: s max and r as defined above, a - coefficient of
subsidence which depend on the roof management techniques
used (fall or stowing methods), d -—thickness- of coal
seams exploited, z - mining depth, § - mean limit angle
(for USGB conditions tg/j" = 1s5 - 2„5), d. - thickness of
individual complexes or formations, fi. - limit angles of
the individual complexes or formations (for explanations
- see Fig. 2 ) . Moreover, the rate of subsidence is pre-
3 73
Engineering and environmental impacts caused by land subsidence
s,T,K,u,e
Zone
of ful
subsidence compression
-r
zone of d e f l e c t i o n ^=H=:
_
— — — — — = J^Weber
= = ^P:
zone 'of era ck i ng ^%zone of f a l l < > ° o
V ? ^ <
r o d i u s of influence
r = z-ctg]3
= Id1-ctg/3i
max.verlical displac.
s.
a l x j • glx)
=_
max. s l o p e
s
max
s
max.curvature
max = ±1,52
min.radius of curvature
R• .min
max.horizontal displac.
U m a x = 0,4s
max.horizontal s t r a i n
£
max
Kmax'
max
s
max = ±0.6
max
FIG. 2 Components of mining subsidence and
prediction equations used in Poland to
calculate geometric characteristics of subsidence troughs.
Explanation of symbols in the text.
dictable, too: (cf. Surface
, 1980, p. 75, Fig.
2.31).
Thus, the topographic effects of mining may be
controlled using up - to - date technologies and or
various coordination and organization practices. However,
there are no possibilities to eliminate mining subsidence
completely.
Despite
all the preventive possibilities, subsidence due to subterranean extraction of pit-coal results
in many, often disastrous effects for both life and property.
/. Liszkowski
374
CONSEQUENCE OF MINING SUBSIDENCE FOR PROPERTÏ AND LIFE IN
THE USCB
As mentioned, mining subsidence cannot be
completely
eliminated, despite
various possibilities to minimalize
the amount of subsidence, the horizontal displacements and
strains created a.s.o» Thus subsidence is an overall
existing constraint for land-use development in areas of
intensive mining activities,, Within Poland this is especially true for the USCB where extensive mining activity
coincide with large urban and industrial development and
a dense population. As a result, quite frequent loss of
property, and casualties too, occur*
There is a broad literature on various kinds of
threats or hazards due to mining subsidence for specified
activities and to people living in the vicinity. All
these are known from the USCB and they are here concentrated to an extremely high degree. 21% of the' whole area
of the Katowice province, i.e. about 1300 km are totally
materially altered? any further land-use development and
any natural recovery of the primary environment are impossible. The area affected directly by mining subsidence^
exceed 650 km 2 and indirectly - 1100 km 2 . The amount of
subsidence actually exceed locally 20 m and will exceed
locally more than 40 m in year 2025. The mean rate of subsidence equals to 100 mm/month and may exceed 500 mm
monthly. The costs that arise due to constructional damages and failures in residential, commercial and industrial
buildings, liners, road and train communications, changes
in soil productivity, loss of cropland and pastureland,
degradation of quality of groundwater and surface water,
land reclamation, loss of coal and aggregate resources
a.s.o., exceeds 1.0 to 2.5 billion dollars yearly (Piatek,
1989). As an instance Table 2 lists the losses of property
in the Katowice province for the year 1985. The. list is
not complete and do not include losses which resulted from
soil degradation, accelerated gullying, landsliding, a» s„o.
which are difficult to fix. Fortunately, loss of life due
to the direct consequences of mining subsidence and the
failure of residential buildings and or other eonstructio*nal works were seldom noticed, even in the.; cases of rapid
ground-surface subsidence, i.e. collapses. The last mentioned type of subsidence in the form of crown holes
collapses is mainly related to areas of old abondoned,
bell - and - pit and pillar - and - stall working mines.
The area occupied by this kind of mining subsidence in
the USCB exceed 350 km2. Fig. 3 presents a more detailed
picture of the areal extent of ground-surface subsidence
due to mining activities in the: USCB-. Areas of strong
mining-induced rock bursting and seismicity are also
delineated. Rock bursting and induced seismisity are an
important secondary hazard related to extensive coal
extraction. Within the time interval between 1980-1985
more than 17500 seismic events of energies E > 10^j where
registered| 2 5 events had energies E > 10°J and 10
above
375
Engineering and environmental impacts caused by land subsidence
TABLE 2 Loss of property as the result of mining
subsidence in the Katowice province for 1985 (after
Piatek, 1989, 90-91, Table 19),
No.
Property
Units
Quantity Approximate
costs
Thousands US:
Loss of land
ha
1521.0
101 760
: cropland
ha
1175.0
82 250
; woodland
ha
189.0
13 230
: investment 1.
ha
157.0
Import and redistribu6 280
tion of drinkable water 106m3
488.0
102 701
Loss of constructional
works
m2
3 120
- residential
5198.7
492.8
m
2
1 132
- commercial
m
787.4
2
680
- industrial
No.
27
2
106
m2
- one-family houses
273.3
10 040
- others
Loss of infrastructural
km
5 932
59.1
systems
km
16.9
932
- water-supply serv.
km
47.8
823
- severage
km
326.8
- gas pipes
66 644
Communications damages
238.3
km
3 000
18
- road communications
4
892
No.
73
2
922
- rail communications
No.
46
2 670
- bridges, viaductes
No.
80.8
ioft,
2 329 390
- trackage systems
228.3
34 700
IOV
- others
Loss of resources
- coal
- aggregates
109j.
The energy of the last events equals to local Richter magnitudes M L > 5 (Zuber, Mutke, Zogala, 1986). It is
this secondary mining-induced hazard which mayfand in factf
results in heavy loss of life.
In all other mining areas of Poland similar consequence of land-subsidence were noticed, although on a much
more local scale.
CONCLUSION
In Poland ground-surface subsidence due to subsurface
exploitation of solid raw materials by mining, brining
and melting-out technologies are a common, although mostly localized, man-made (anthropogenic) phenomenon. There
376
/. Liszkowski
Tarnowskie Gôry
FIG. 3 Hazards related to coal mining in
the USCB, southern Poland.
1 - continuous mining subsidence ; amount of
subsidence above 5- m; 2 - areas of collapses
and other kinds of discontinuous subsidence ;
3 - areas of increased seismicity for 19801985| 4 - localities of catastrophic rock
bursts (E > 109j of events) for 1980-1985;
5 - predicted values of subsidence in meters;
6 - the boundaries of the USCB| 7 - northern
boundary of the Carpathian orogen.
is one area - the Upper Silesian Goal Basin - where mining subsidence is both extensive and fast. And it is here^
that all the negative consequences of mining activities
are concentrated to an extent, that they are not only a
potential but real hazard for property and life. The loss
of property equals yearly from 1 to 2*5 billion dollars.
The threat of life, mainly as the result of catastrophic
rock bursting and or mining-induced seismicity is a heavy
stress to all the people living within this area* And
these are more than 3 million residents»
The socio-economic situation in Poland is such that
it is not possible to resettle people away from even the
377
Engineering and environmental impacts caused by land subsidence
most hazardous areas. Thus, we can only hope that there
will he
better times for preservation, more exactly; for
restoration and reclamatioan of the environment in the
USGB.
ACKNOWLEDGMENTS I wish to. thank. Arnold I. Johnson for
thoughtful and constructive review of the: manuscript and
Gf'. Rozmiarek for manuscript preparation. Financial support
from the U.S. National Science Foundation which allows me
to attend the Fourth International Symposium on land Subsidence in Houston, Texas, USA is especially gratefully
acknowledged.
REFERENCES
H.M.S.O. (1949) Inter-Departmental Committee Report on
Mining Subsidence. Report of Committee of Mining Subsidence, Cmd 7637.
Kratzsch, H. (1974) Bergschadenkunde. Springer-Verlag,
Berlin.
Liszkowski, J. (1989) Anthropogenic ground-surface deformations in Poland: their formation, distribution,
geometric and kinematic characteristics and engineering-geological risks (in Polish). In: Inzyniersko-geologiczne problemy srodowiska czlowieka (Engineeringgeological problems of the Environment), 258-301,
Warszawa.
National Coal Board (1966) Subsidence Engineers Handbook,
London.
Piatek, F. (ed.) (1989) Costs of ground-surface degradation in the Katowice province (in Polish). Polish
Academy of Sciences, Wroclaw.
Surface ... (1980) Surface protection against mining
damages (in Polish). Wyd. Sla.sk, Katowice.
Zuberek, W., Mutke, S.
Zogala, B. (1986) Mining induced
seismicity of the Upper Silesian Coal Basin (in Polish).
In: Konstantynowicz, E. (éd.), Problemy ochrony srodowiska i. zasobow naturalnych w wojewodztwie katowickim.
PTPNoZ, Oddz. Gornoslq.ski, Sosnowiec.