loss of slope stability on railway tracks and its sanation · loss of slope stability on railway...
TRANSCRIPT
1
Loss of slope stability on railway tracks and its sanation
Petr
Černoch
AGE a.s. -
applied geotechnics and ecology, Czech Republic
XVIII EYGEC, Ancona
/ Portonovo, Italy –
June 17-20, 2007
2
Structure of the lecture
Description
of each case
location – maprailway track – cutting / embankmentgeology – profile / conditionslandslide – causessolution – sanation
Case studies
based on experience in situ
JenišovČeské BudějoviceVeselí n. Lužnicí
3
1. JENIŠOV –
locationsouth west of Bohemianearby border with Austriaalongside water reservoir Lipno
4
1. JENIŠOV –
railway track and geologyrailway track – cutting
800 m long5 to 7 m deepinclination approx. 45°
geological profile – km 61.900; EC-7humic soilclayey sands with fragments of bedrockbedrock – biotitic gneisses and granulites
5
1. JENIŠOV –
landslide causesoriginal drainage system damaged in the course of time
winter 2006 – heavy rains=> water accumulation between
sands and bedrock
photo: P. Novotný photo: P. Novotný
6
1. JENIŠOV –
sanationsetting up a gabion retaining wall recovering the drainage system
(drain ribs, ditch)
photo: P. Novotný photo: P. Novotný
7
2. ČESKÉ
BUDĚJOVICE –
locationsouth of Bohemiamain connection between Czech Republic and Austria
8
2. ČESKÉ
BUDĚJOVICE –
railway track and geologyrailway track – cutting
100 m long5 to 7 m deepinclination approx. 45°bottom – old retaining wall
geological profile – km 211.380; EC-7humic soilclayey gravel sands with bouldersimpermeable clays (stiff consistency)occasional springs
9
2. ČESKÉ
BUDĚJOVICE –
landslide causesexcavation for cable harness
poorly compacted => water ran through the slope
and not on the surface
spring 2006 – spring thaw=> water accumulated above
underlying impermeable layers
photo: P. Novotný photo: P. Novotný
10
2. ČESKÉ
BUDĚJOVICE –
sanationsubstitution of the old wall by a new gabion retaining wall
construction of a drainage systemrelocation of the cable harness
photo: R. Smolík
11
3. VESELÍ
N. LUŽNICÍ
–
locationsouth east of Bohemiarailway track from České Budějovice to Pragueflat landscape with rivers and ponds
12
geological conditionstertiary basin – flood plainsediments – kaolin clays, sandscovered by Qrternary sands, loams
railway track – embankment500 m longup to 4 m highapprox. 35° steep
3. VESELÍ
N. LUŽNICÍ
–
railway track and geology
photo: P. Novotný
13
3. VESELÍ
N. LUŽNICÍ
–
landslide causesembankement body during floods
acts as a barrier / damwater flow possible through the bridges
in 1980s main bridge destroyed and filled up
=> during floods in 2002 and 2006 deformations appeared
photo: P. Novotný
14
3. VESELÍ
N. LUŽNICÍ
–
sanationplan
surface water-protectionconstruction of a small culvert
realityonly embankment body restorationproblems will probably last
photo: P. Novotný
15
Conclusions
Loss of slope stability on railway tracks can be prevented mainly by:
knowing the natural conditions based on qualitygeological research
designing the right technological procedures
complying with them throughout the construction
maintaining the existing drainage system
16
Thank you for your attention
ContactPetr ČernochAGE a.s., Czech [email protected]+420 222 714 962 AGE a.s. - applied geotechnics and ecology