Simplicity of sliding / Jednostavnost klizanja
Biljana Abolmasov, Belgrade, Serbia
Klizište Mala Vinča smješteno je 14 km jugoistočno od Beograda, u selu Vinča, na brdovitom terenu (nadmorska visina 80-130 m) na desnoj obali Dunava. Teren je karakteriziran brojnim dubokim klizištima čije nožice dosežu rijeku Dunav. Generalni profil klizišta, od površine prema dubini, je sljedeći: površinska naslaga debljine do 0.2 m; les debljine 1 – 1.5 m; laminirani dobro zbijeni pijesci i trošni lapori sarmatske starosti. Klizište je aktivirano u ožujku 2008. godine zbog obilnih oborina i zasijecanja padine za potrebe gradnje stambenih objekata. Prvi puta klizište je reaktivirano u travnju 2009. godine, također uslijed obilnih oborina. Drugo reaktiviranje klizišta dogodilo se u drugim dijelu prosinca 2009. godine, uslijed naglog otapanja snježnog pokrivača. Klizište Mala Vinča primjer je reaktiviranog plitkog retrogresivnog klizišta, vrlo sporog do sporog. Glavna pukotina sa skokom visine 1.7 m jasno je vidljiva, kao i zona usijedanja. Na fotografiji je prikazan dio klizne plohe vidljiv na površini terena. Klizište ima dimenzije 50 m x 40 m i nalazi se u središnjem dijelu padine iznad rijeke Dunav, odnosno iznad lokalne ceste i tri privatna stambena objekata koji su izravno ugroženi klizištem.
The landslide “Mala Vinča” is located 14 km southeast of Belgrade in the village of Vinča, at the hilly terrain (altitude of 80-130 m) of the Danube River right bank. Terrain is characterized by numerous deep landslides whose feet reach the Danube. The general geological profile of the landslide is (from the surface to the depth): superficial deposit (thickness up to 0.3 m); loess (thickness 1 – 1.5 m); Sarmatian laminated well-compacted sand with weathered marls. The landslide activated in March 2008 was triggered by heavy rainfall and slope cutting for the purpose of construction of residential buildings. First reactivation occurred in March 2009, also triggered by heavy rainfall. Second reactivation occurred in late December 2009 and was triggered by instant snow melting. The Mala Vinča landslide is an example of reactivated shallow retrogressive landslide, very slow to slow. The main scarp (height of 1.7 m) is clearly visible as well as zone of mass deficit. Photograph shows part of sliding surface visible at the ground surface. The landslide has the dimensions of 50×40 m and it is situated in the middle of the slope, above the local road and three private residential houses that are directly endangered with sliding.
The Road 2 / Cesta 2
Željko Arbanas, Rijeka, Croatia
Slika prikazuje klizište Drazej dan nakon klizanja koje je zahvatilo regionalnu cestu blizu grada Pazina u Istri. Predstavnici lokalne uprave i inženjeri iz Uprave za ceste obišli su klizište kako bi razmotrili okolnosti i posljedice.
Klizište Drazej se nalazi u blizini grada Pazina u središnjem dijelu Istre. Inicijalni znakovi klizanja na klizištu Drazej, u vidu otvorenih pukotina, uočeni su 2. siječnja 2005. godine nakon razdoblja obilnih oborina. Daljnje klizanje nije bilo moguće spriječiti niti jednom mjerom zaštite, a promet je preusmjeren na jednu traku, dalje od otvorenih pukotina. Glavno klizanje je aktivirano 5. siječnja 2005. godine kada je došlo do značajnog oštećenja prometnice. Klizište se više nije moglo zaustaviti, tako da je i 30 dana nakon pojave prvih vlačnih pukotina nasip ceste klizio niz padinu. Istražnim radovima je utvrđeno da je volumen kliznog tijela oko 10.000 m3 s kliznom plohom na granici između glinovitih naslaga pokrivača i flišne stijenske mase. Izravni uzrok klizanja bile su obilne oborine. Na žalost, voda drenirana s ceste koncentrirala se na padini ispod nasipa ceste. Istražnim bušenjem je utvrđeno da su se kroz povijest na istoj lokaciji dogodila brojna klizanja, međutim točni datumi reaktiviranja klizanja su nepoznati. Klizanjem je bio otvoren presjek na kojemu su bile vidljive višestruke rekonstrukcije ceste i ostaci stare konstrukcije ceste, na dubini od čak 3,6 metara ispod postojeće konstrukcije.
The picture presents the Drazej landslide overtaken regional road near the City of Pazin in Istria, Croatia, a day after sliding. Representatives of the local authority and engineers from the office for road maintenance visited the landslide to consider circumstances and consequences.
The Drazej landslide is located near the City of Pazin in central part of the Istrian Peninsula. The initial sliding signs (open cracks) of the Drazej landslide were observed on 2nd January 2005, after a period of heavy rainfalls. Traffic was reduced on one lane away from open cracks, but it wasn’t possible to conduct any other prevention measure to stop further sliding. Major sliding occurred on 5th January 2005 and caused significant damages of the road. After the first appearance of open tension cracks, the landslide could not be restrained anymore and in the next 30 days the road embankment was sliding down the slope. Based on field investigation results it was established that the landslide volume is approximately 10,000 m3 with slip surface on the contact of clayey superficial deposit and flysch bedrock. The sliding was directly caused by a large precipitation amount. Unfortunately, the drainage water from the road was concentrated at the slope below the embankment. The field investigation indicated that multiple reactivated sliding occurred on this location throughout the history, but the exact data about former slidings were not available. From the visible cross section after sliding it can be seen that the road was reconstructed many times and the remains of the old road construction, caused by old slidings, were found 3.6 m below the existing construction.
The Grohovo Landslide / Klizište Grohovo
Željko Arbanas, Rijeka, Croatia
Klizište Grohovo je najveće aktivno klizište na hrvatskom dijelu jadranske obale, a smješteno je na sjeveroistočnoj padini doline Rječine. Tijekom 19. i 20. stoljeća uočene su značajne nestabilnosti na padinama doline Rječine. Posljednje retrogresivno kompleksno klizište reaktiviralo se u prosincu 1996. godine, nakon dugog razdoblja mirovanja. Tom je prilikom 1×106 m3 materijala pokrenuto niz padinu i zatrpano je korito Rječine. Nakon početnih pomaka klizište se razvijalo retrogresivno, pri čemu je zahvaćalo sve više dijelove padine. Smatra se da je klizna ploha na granici između površinskih naslaga i fliša u podlozi. U Državnom arhivu u Rijeci pronađeni su mnogi povijesni zapisi, slike i karte koji opisuju klizišta i dokumentiraju pojave klizanja u dolini rijeke Rječine u blizini sela Grohovo. Klizanja su prvi put dokumentirana 1767. godine, kada je potres iz 1750. godine s epicentrom u gradu Rijeci uzrokovao mnogobrojna klizišta i odrone u dolini Rječine. Krajem 19. stoljeća oborine i poplave aktivirale su velika klizišta na obje obale rijeke blizu sela Grohovo. Veliko klizište na jugozapadnoj padini dogodilo se 1870. godine, a nakon njegove ponovne aktivacije 1885. godine dio sela Grohovo je zatrpano kamenom lavinom. Veliko klizište na sjeveroistočnoj padini doline Rječine dogodilo se 1893. godine, na lokaciji sadašnjeg klizišta, a dokazi klizanja su još uvijek vidljivi.
The Grohovo Landslide, the largest active landslide along the Croatian part of the Adriatic coast, is located on the north-eastern slope of the Rječina River Valley. It was noted that during 19th and 20th centuries considerable instabilities on the Rječina Valley slopes occurred. The last complex retrogressive landslide was reactivated in December 1996, after long dormant period and about 1.0×106 m3 moved down the slope and buried the Rječina river-bed. After initial movements, the landslide retrogressively developed up the slope. Slip surfaces are considered to be on the contact of superficial deposits and flysch bedrock. Numerous historical records, figures and maps describing landslides were found in the Croatian State Archive in Rijeka and provide evidence of the occurrence of landslides in the Rječina River Valley near the Grohovo Village. Sliding was first documented in 1767, when numerous landslides and rockfalls in the Rječina River Valley were caused by the earthquake in 1750, which had an epicenter in the City of Rijeka. Large landslides triggered by rainfall and floods were noticed on both river banks near the Grohovo Village at the end of 19th century. A large landslide occurred on the southwestern slope in 1870, and after reactivation of the slide in 1885 part of the Grohovo Village was buried by a rock avalanche. A large landslide occurred in 1893 on the northeastern slope of the Rječina River Valley at the location of the recent landslide, and evidences of this sliding are still visible.
Remains of Brus landslide / Ostaci klizišta Brus
Sanja Dugonjić Jovančević, Rijeka, Croatia
Na fotografiji je prikazano klizište Brus četiri godine nakon njegova nastanka. Klizanje se dogodilo 9. travnja 2005. godine u 15:15 sati, u blizini sela Brus u Istri. Ovo klizište je tipično blokovsko, a klizno tijelo se sastoji od jednog gotovo neporemećenog bloka flišne stijenske mase, dugačkog 150 m i širokog 35 m. Klizanje je uzrokovala nepovoljna orijentacija slojeva, koji su paralelni s padinom, a u donjem dijelu padine su otkriveni zbog erozije rijeke. Klizanje je inicirano obilnim oborinama. Orijentacija slojeva u stijenskoj masi varira od 220/13 do 225/19, dok je njezina srednja vrijednost 223/14. Glavna pukotina klizišta dijelom je zahvatila lokalnu cestu, te ju je značajno oštetila. U flišnoj stijenskoj masi se izmjenjuju slojevi pješčenjaka i lapora, koji su na površini prekriveni tankim pokrovom glinovitih tala koluvija i rezidualnog tla. Klizna ploha se nalazi unutar trošne zone fliša, na granici između slabo trošnih i svježih pješčenjaka. Pokrenuta masa je zatrpala potok, zbog čega je nastalo malo jezero u nožičnom dijelu klizišta.
The photo is taken four years after the occurrence of the Brus landslide. Sliding occurred near the Brus village (Istria, Croatia) on April 9, 2005, at 3.15pm. The movement was a typical translational block sliding with a landslide body consisting of one almost-undisturbed flysch rock mass block 150m long and 35 m wide. The sliding was caused by the unfavorable orientation of the bedding planes, parallel to the slope and dipping out of it in the lower part due to river erosion, while intensive rainfalls were the triggers. The general orientation of rock mass bedding planes varies from 220/13 to 225/19, with an average value of 223/14. Landslide damaged the local road located close to the main scarp. The involved rock mass consists of alternating layers of sandstone and marl, covered by a thin, clayey superficial deposit of colluvium and residual soil. The slip surface was identified inside the weathered zone, on the contact between the slightly weathered and fresh siltstone. The displaced mass formed a small landslide lake in the foot part.
View at the Grohovo landslide / Pogled na klizište Grohovo
Sanja Dugonjić Jovančević, Rijeka, Croatia
Slika prikazuje klizište Grohovo koje predstavlja najveće aktivno klizište na hrvatskom dijelu jadranske obale. Ovo klizište smješteno je na padinama rijeke Rječine, koja je jedan od najznačajnijih vodotoka u primorskoj Hrvatskoj. Dolina se nalazi u seizmički aktivnom području u zaleđu grada Rijeke. Gornji i središnji dio doline rijeke Rječine oblikovan je u relativno uskoj zoni paleogenskih siliciklastičnih stijena, koje su sa jugozapadne i sjeveroistočne strane okružene vapnenačkim stijenama paleogenske i gornjo-kredne starosti. Prve nestabilnosti na tom području zabilježene su 1870. godine. Iako se u 21. stoljeću događaju nova klizanja na obje strane doline rijeke Rječine, posljednje najveće klizište se dogodilo 5. prosinca 1996. godine na sjeveroistočnoj padini (prikazano na fotografiji), nakon dugog kišnog razdoblja. Velika količina pokrenutog materijala (ukupnog volumena 850.000 m3) dosegla je korito rijeke Rječine i gotovo ga u potpunosti zatrpala. Ispuštanje vode sa brane Valići odmah je zaustavljeno kako bi se omogućilo čišćenje korita rijeke od materijala klizišta kojim je bilo zatrpano. Na temelju novijih istraživanja ustanovljeno je da se radi o kompleksnom retrogresivnom klizištu, koje je napredovalo od nožice prema vrhu padine, a koje se sastoji od 13 kliznih tijela i uključuje i značajne pomake velikih blokova na vrhu padine. Ova fotografija snimljena je 12 godina nakon posljednjeg velikog kretanja klizišta. Fotografija je snimljena sa suprotne, jugozapadne strane doline, gdje je danas instalirana totalna stanica koja prati kretanje klizišta.
Photo shows Grohovo landslide, which is the largest known landslide on the Croatian part of the Adriatic coast. It is placed along one of the most important aquifer in the Croatian littoral, Rječina River. This valley is a part of the seismic area in the background of the City of Rijeka. The upstream and central part of the river valley, are formed in relatively narrow zone of Palaeogene siliciclastic rocks, which is from the south-west and north-east side surrounded with Palaeogene and Upper Cretaceous limestone rocks. First instabilities in this area were registered in 1870. Although new movements of the mass appeared in the 21st century on both sides of the Rječina River Valley, the last large landslide occurred on the 5th December 1996, on the north-eastern slope (shown on the photograph), after a long rainy period. Huge mass of displaced material (total volume was about 850,000 m3) has reached the Rječina River bed and has almost buried it. The water overflow from the Valići Dam was immediately suspended to enable excavation of the landslide material from the buried river channel. According to recent investigations, the landslide is interpreted as a complex retrogressive landslide, with 13 landslide bodies and considerable movements of large blocks in the top of the slope. Photograph was taken 12 years after the last significant movement, from the opposite, south-western slope of the valley, where total station for landslide monitoring is installed today.
Stupica rockslide / Odron Stupica
Mirko Grošic, Rijeka, Croatia
Tijekom posljednjeg desetljeća dogodili su se veći odroni na strmim vapnenačkim padinama duž hrvatskog dijela jadranske obale. Oni su uzrokovali ozbiljne štete na građevinama i posebno na prometnicama, kao i usporavanje prometa. Naselja i prometna infrastruktura, koji su smješteni na strmim stijenskim padinama posebno su ranjivi s obzirom na odrone. Jedan od primjera takvih odrona dogodio se u Dalmaciji na lokaciji Stupica na državnoj cesti D8 između Makarske i Vrgorca. Do odrona blokova vapnenačke stijenske mase došlo je 24. listopada 2010. godine i to zbog planarnog i klinastog sloma u strmo zasječenoj stijenskoj masi. Cesta je bila zatvorena oko 10 mjeseci nakon odrona, te je morao biti izgrađen obilazni tunel kroz padinu kako bi se omogućio promet.
During last decade some large rockfalls occurred on the steep limestone slopes along Croatian side of the Adriatic Coast. They caused serious damages on buildings and especially on traffic facilities, as well as delayed traffic on roads. Settlements and transportation facilities in coastal areas with steep rock slopes are vulnerable to rockfalls. One example of these rockfall occurred near location Stupica in Dalmatia, at national road D8 between Makarska and Vrgorac. Stupica rockslide in limestone rock mass occurred on 24th October 2010. This was combination of planar and wedge failures in steep rock mass slope. Road was closed for about 10 months from rockfall event and a bypass tunnel was constructed through the slope to enable transport.
Higashi-Takezawa landslide / Klizište Higashi-Takezawa
Hideaki Marui, Niigata, Japan
Mid Niggata Prefacture potres je 23. listopada 2004. godine uzrokovao klizište Higashi-Takezawa. Slika prikazuje glavnu pukotinu klizišta koje je otklizalo oko 70 metara. Klizna masa je zaustavila tok rijeke Imo formirajući tako branu klizišta. Duljina klizišta je 350 metara, a širina 300 metara. Dubina klizne plohe je 30 metara. Volumen klizne mase je 1,3 milijuna m3. Klizna ploha je formirana na granici između pješčenjaka i prahovnjaka u njihovoj podlozi, s nagibom slojeva od 20 stupnjeva. Akumulirana voda je poplavila mnoge kuće u naseljima u uzvodnom toku rijeke Imo. Razina vode raste iz dana u dan. Branu izgrađuje vrlo mekani i slabi materijali, te postoji mogućnost sloma tijela brane. Prelijevanje akumulirane vode i slom brane dovelo bi do katastrofalnih poplava i tokova debrisa, koji bi uništili naselja u nizvodnom dijelu rijeke Imo. Stoga je apsolutno potrebno sniziti razinu vode kako bi se spriječilo prelijevanje i slom brane formirane od klizne mase.
Higashi-Takezawa landslide was caused by the Mid Niigata Prefecture Earthquake on 23rd October 2004. The photo shows the head scarp of the landslide which slid down from right down to left up about 70 m. The slid soil mass blocked the river course of Imo-River and formed a landslide dam. The length of the landslide is 350 m and the width is 300 m. The depth of sliding surface is 30 m. The volume of the slid soil mass is 1.3 million m3. The soil mass slid down along the formation boundary between upper sandstone and lower siltstone with inclination of 20 degrees. Many houses of upwards settlements along the Imo-River were impounded by the dammed water. The water table was getting increased day by day. There was apparent danger of dam collapse because of very soft and weak material of the dam body. If the landslide dam would collapse by overtopping of the reservoir water, catastrophic flood or debris flow could occur together with attack of the downwards settlement along the Imo-River. Therefore, it was absolutely necessary to lower the water table in order to avoid overtopping and collapse of the landslide dam.
A hole in a small village / Rupa u malom selu
Sorin Petru Milutinovici, Bucharest, Romania
Klizište se nalazi u selu Seciurile (Valcea) u Rumunjskoj. Do danas nije objavljena niti jedna geotehnička studija uzroka klizišta, međutim, prema mnogim izvorima smatra se da je postanak ovog klizišta povezan sa starim rudnikom ugljena koji se nalazi na tom području. Iako se ugljen eksploatira površinski tijekom posljednjih desetljeća, također su zabilježene i podzemne eksploatacije u prošlosti.
Iako postoje mnoga mala i srednje velika klizišta raspršena oko Seciurile i obližnjih sela, najveće klizište se dogodilo 4. svibnja 2006. godine. Prema navodima lokalnog stanovništva, u samo nekoliko sati otvorila su se dva jarka, širine 30 do 60 metara, duboka 4 do 10 metara. Od ukupno 220 kućanstava, samo 20 njih nije bilo oštećeno. Zbog veličine ovog klizišta, lokalna i državna uprava odlučila je iseliti stanovništvo i premjestili selo Seciurile. Međutim premještanje sela još uvijek nije dovršeno.
Slika je snimljena 29. lipnja 2006. godine, gotovo dva mjeseca nakon klizanja.
The landslide is located in Seciurile Vilage, Valcea County, Romania. No geotechnical study regarding the cause has been published, but, various collateral studies suggest a strong relation with old coal mining in the area. Coal was mined in quarries during the last decades, but, underground mining was recorded in the past.
Although there are many small and medium landslides scattered Seciurile and neighboring villages, the biggest ones have happened on 4th May 2006, in a matter of hours (according to the locals) and determined the birth of two large ”trenches”, 30 to 60 meters wide and 4 to 10 meters deep. Out of 220 households, only 20 were not affected. Due to the extent of the landslide, the local and national authorities decided that the village of Seciurile should be relocated. The relocation is still not finished.
The picture was taken on 29th June 2006, almost two months after the landslide.
Broken garage / Polomljena garaža
Sorin Petru Milutinovici, Bucharest, Romania
4 svibnja 2006. godine, u samo nekoliko sati (prema lokalnom stanovništvu ) pojavila su se dva velika jarka u malenom mjestu Seciurile (Valcea, Rumnjska). Ovime je ozbiljno pogođeno 200 od ukupno 220 zgrada u selu, a među njima je i ova velika garaža koja je korištena u okviru rudarskih radova.
Niti jedna geotehnička studija o uzroku klizišta do danas nije objavljena, međutim smatra se da je klizanje povezano s nekadašnjom eksploatacijom ugljena na tom području. Iako se ugljen eksploatira površinski tijekom posljednjih desetljeća, također su evidentirane i starije podzemne eksploatacije.
Zbog veličine klizišta, lokalna i državna uprava su odlučile iseliti stanovnike i premjestili selo Seciurile. Međutim, premještanje sela do danas još uvijek nije dovršeno.
Slika je snimljena 29. lipnja 2006. godine, gotovo dva mjeseca nakon klizanja. Začuđujuće je to da je garaža još uvijek u upotrebi, nakon što su polomljena stakla zamijenjena drvenim pokrovima.
On 4th May 2006, in a matter of hours (according to the locals), two big trenches appeared through a small village called Seciurile, Valcea County, Romania. 200 out of a total of 220 buildings in village where seriously affected, among those being this large garage that was used by the local mining operation.
No geotechnical study regarding the cause of the landslide has been published, but, various collateral studies suggest a strong relation with old coal mining in the area. Coal was mined in quarries during the last decades, but, underground mining was recorded in the past.
Due to the extent of the landslide, the local and national authorities decided that the village of Seciurile should be relocated. The relocation is still not finished.
The picture was taken on 29th June 2006, almost two months after landslide. Amazingly, the garage was still used, after all broken windows where replaced by plywood.
Old man on wrecked porch / Starac na uništenom trijemu
Sorin Petru Milutinovici, Bucharest, Romania
Starčeva kuća je gotovo uništena velikim klizištem u mjestu Seciurile (Valcea, Rumunjska). Do danas nije objavljena niti jedna geotehnička studija o uzroku klizišta, ali se smatra da je ono povezano sa starim rudnikom ugljena koji se nalazi na tom području. Iako je posljednjih nekoliko desetljeća ugljen eksploatiran površinski, zabilježene su i podzemne eksploatacije u prošlosti.
Klizište aktivirano 4. svibnja 2006. godine zahvatilo je 200 od ukupno 220 kuća u selu i u samo nekoliko sati (prema lokalnom stanovništvu) otvorila su se dva jarka, širine 30 do 60 metara, duboka 4 do 10 metara.
Zbog veličine klizišta, lokalna i državna uprava su odlučile iseliti stanovnike i premjestiti selo Seciurile. Međutim, to do danas još uvijek nije dovršeno.
The old man’s house was almost destroyed by a big landslide in Seciurile Village, Valcea County, Romania. No geotechnical study regarding the cause of the landslide has been published, but, various collateral studies suggest a strong relation with old coal mining in the area. Coal was mined in quarries during the last decades, but, underground mining was recorded in the past.
The landslide that affected 200 out of 220 houses in the village happened on 4th May 2006, in a matter of hours (according to the locals) and gave birth to two large ”trenches”, 30 to 60 meters wide and 4 to 10 meters deep.
Due to the extent of the landslide, the local and national authorities decided that the village of Seciurile should be relocated. The relocation is still not finished.
Mass movement occurred on Synej village, Kavaja region, Albania / Pokreti masa u selu Synej, pokrajina Kavaja, Albanija
Ylber Muceku, Tirana, Albania
Prikazano klizanje tla dogodilo se u brdovitom području u regiji Kavaja u Albaniji. Klizna ploha je formirana na trošnoj zoni molasnih stijena. Klizište je nastalo u tlima i stijenama koje se sastoje od izmjene slojeva glinjaka i prahovanjaka s pješčenjacima. Gornji dio litološkog profila izrazito je trošan. Pokret na padini je prouzročen: dubokim profilom trošnosti, nepovoljnom orijentacijom slojevitosti i starim pukotinama u stijenskoj masi. Osim toga, ostali glavni uzorci klizanja bili su: nagib padine (16-25°), hidrogeološki uvjeti (tečenje podzemne vode kroz trošnu zonu molasnih stijena s istjecanjem vode iz 2 izvora u dnu padine; obilne oborine), ljudske aktivnosti (7 izgrađenih zgrada). Kombinacija ovih faktora dovela je do degradacije fizičkih i mehaničkih svojstava tla i stijena. Klizanje tla dogodilo se u selu Synej 21. ožujka 2009. godine, 11 dana nakon jakih kiša. Površina klizišta je 38.600 m2, a dubina klizanja je 10-13 metara. Aktiviranjem klizišta uništeno je 7 novih zgrada, a ugroženo je 9 zgrada.
This earth slide type landslide has occurred on hills slope in Kavaja Region, Albania. The sliding surface is formed above the weathering zone of molasses rocks. The landslide is developed in soils and interchange of claystone and siltstone layers with sandstones. The upper part of lithological profile is highly weathered. Slope movement is caused by: deep weathering profile; unfavorable bedding orientation; and old fracture in rock mass. Beside of them, other major factor for landslide occurrence are: slope angel (16-25°), hydrogeology conditions (groundwater flow through weathering zone of molasses rocks with evidence of 2 springs found in lower part of the slope and heavy rains), manmade activities (7 buildings constructed). The interplay between these factors has contributed to reduction of physical and mechanical soil and rock properties. Earth slide type landslide occurred in Synej village on March 21, 2009, 11 days after heavy rain. Landslide area is 38,600 m2 and the landslide depth is between 10 and 13 meters. Landslide activation demolished 7 new buildings and threatened 9 buildings.
The landslide attack river / Klizište je napalo rijeku
Toni Nikolić, Sarajevo, Bosnia and Herzegovina
Ogromno klizište u Bogatiću, u blizini Trnova, dugačko je gotovo 3 kilometra i prijeti hidroelektrani s branom na rijeci Zeljaznica. Postoji mogućnost da klizište zatrpa korito rijeke i stvori umjetnu branu. Postoji potencijalna opasnost od mogućeg sloma umjetne brane i formiranja vodnog vala koji bi poplavio naselja u blizini Sarajeva. Klizište Bogatić je reaktivirano 2011. godine nakon dugog razdoblja obilnih oborina. Tijekom 2012. godine klizište je djelomično stabilizirano, te je hidroelektrana ponovno puštena u pogon.
Slika je snimljena 29. lipnja 2006. godine, gotovo dva mjeseca nakon klizanja. Začuđujuće je to da je garaža još uvijek u upotrebi, nakon što su polomljena stakla zamijenjena drvenim pokrovima.
This huge landslide in Bogatic, near Trnovo is long more than 3 km. It endangered hydropower plant with dam on river Zeljaznica, with possibility to burry river by landslide dam. There is potential hazard of breaking landslide dam and subsequent flooding of settlements near the border of the city of Sarajevo. The Bogatic landslide was reactivated in 2011 after prolonged period of rain. In 2012 landslide was partially stabilized and hydropower plant starts to work again.
The mudflow of Chirilesti, the Buzau County, Romania / Blatni tok Chirilesti, Buzau, Rumunjska
Adrian Ionescu, Bucharest, Romania
Blatni tokovi se javljaju u brdovitom području u bujičnim dolinama s desne strane rijeke Buzau, u proljeće nakon topljenja snijega. Jedan takav blatni tok dogodio se u veljači 2010. godine na lokaciji Chirilesti, u regiji Buzau. Bujična dolina u kojoj se klizanje dogodilo dugačka je oko 1.300 – 1.500 m s nagibom od oko 20 – 25°. Sve je započelo u gornjem toku gdje se nalazi depresija u obliku kotlića u kojoj se sakuplja snijeg. U geološkom pogledu, padine doline izgrađene su od stijena u kojima se izmjenjuju glineni škriljavci i pješčenjaci, što je karakteristično za naslage fliša. Gornji dio kosine, ekstremno poremećen klizanjem, izgrađen je od glinovitog materijala. Ta glinovita masa zajedno s odlomcima škriljavca i pješčenjaka, u prisutnosti vode se mijenja u nevezanu masu koja teče duž doline. S kinematičke točke gledišta, energija pokrenutog materijala duž padine je ekstremno visoka i smanjuje se tek na obali rijeke Buzau, gdje debljina deponirane klizne mase iznosi 4-5 m.
The mudflows occur in torrential valleys situated in an upland zone on the right side of the Buzau River after snow melting in spring time. One of these is the mudflow occurred in February 2010, near the Chirilesti location, in the Buzau County. The torrential valley, where the slide was occurred, has a length of approximately 1,300 – 1,500 m and an inclination of approximately 20 – 25°. A bucket shape depression exists in the upper part of landslide, in which snow is gathering. From the geological point of view, the setting of valley’s slopes is consisting of alternated layers of clayey schist and sandstones, characteristic for the flysch deposits. This upper part of the slope, extremely disturbed by sliding, is consists of clayey material. This clayey mass with schist and sandstone fragments, after snow melting and water content rising, was changed into a cohesionless mixture which flow along the valley. From the kinematic point of view, the displacement energy of the gathered material is extremely high along the slope, and decreases near the Buzau river bank, where the deposed material mass was approximately 4 – 5 m thick.
Slip surface at the Konšćica Landslide / Klizna ploha na klizištu Konjšćica
Bruno Škacan, Zagreb, Croatia
Tijekom iskopa građevne jame na lokaciji stambene zgrade u Konšćici aktivirano je klizanje u gornjem dijelu kosine. Klizište je aktivirano u ukupnoj dužini L=10 m i širini B=5m s tendencijom širenja. Lokaciju izgrađuju debele naslage sastavljene od izmjene slojeva šljunaka, pijesaka, siltita i glina. Općenito, slojevi gline u području kosine su vrlo rijetki zbog nedovoljnog stupnja kemijskog trošenja izvorne stijenske mase, ali postoje tragovi slojeva sive gline. Klizna ploha nastale nestabilnosti razvijena je tijekom iskopa građevne jame duž jednog takvog sloja saturiranog vodom. Istražnim radovima na klizištu uočen je tanki, vlažni, zaglađeni sloj sive gline visoke plastičnosti duž koje se razvila klizna ploha na dubini od 3-4 metra ispod površine. Slični tipovi mehanizama pojave klizišta su uočeni i na nekoliko lokacija blizu Zagreba, gdje uočeno postojanje razmekšanog sloja gline uvjetuje položaj klizne plohe pri pojavi klizanja.
Karakteristike takvih ploha je mala debljina (oko 1 mm) s vrlo niskim (rezidualnim) parametrima čvrstoće c = 0 kPa, ϕ = 8-12°. Preliminarne mjere sanacije izvedene su zatrpavanjem građevne jame u nožici klizišta kako bi se osigurao odgovarajući aktivni otpor klizanju i spriječio daljnji razvoj klizanja, dok je kao trajna mjera sanacije projektirana usidrena pilotska stijena.
During the open pit excavation at the location of a residential building in Konšćica, a landslide at the uphill part of the slope has been activated. Landslide has been activated within the length of approximately L = 10 m and the width of approximately B = 5 m, and tends to enlarge. Location is built in thick sediments composed of gravel, sand, silt and clay layers interchanges. Generally, the clay layers in the slope area are very rare due to insufficient degree of chemical disintegration of the originate rock mass, but there is an evidence of gray clay layers existing in the slope. The slip surface of the landslide was developed along one of this clay layer saturated with water during an open pit excavation. During the field investigations at the landslide, the thin, wet, smoothed film of high plasticity grey clay was found along the slip surface that was developed at the depth of 3-4 m below the surface. The similar mechanism of sliding had been observed at several locations nearby Zagreb where the existence of a weakened clay layer predefine position of landslide slip surface.
Characteristic of such layers is very thin thickness (approximately 1 mm) with very low (residual) strength parameters c = 0 kPa, ϕ = 8-12°. As preliminary remediation countermeasures, the pit was filled in the toe of the landslide to ensure necessary active resistance and prevent further sliding, while an anchored pile wall was designed as the permanent remediation construction.
Translational block sliding in marls at the Bijeli Brijeg location / Translacijsko blokovsko klizanje u laporima na lokaciji Bijeli Brijeg
Željko Sokolić, Zagreb, Croatia
Aktivno klizište na lokaciji Bijeli Brijeg ima procijenjene slijedeće dimenzije: dužina L>100 m, širina B>50 m, dubina klizanja D=3 do 5 m. To je translacijsko blokovsko klizanja predisponirano položajem diskontinuiteta u laporima. U gornjem dijelu klizišta dogodio se pomak bloka od približno 10 m.
Klizište se nalazi na padini između dvije lokalne prometnice. Glavna pukotina nalazi se oko 10 metara od gornje prometnice dok je nožica klizišta zatrpala donju prometnicu i onemogućila odvijanje prometa.
Brojni su faktori koji su doveli do aktiviranja klizišta kao što su: geotehničke značajke lokacije koje su pogodne za klizanje (nagib padine, slojevitost u naslagama lapora, nagib slojeva, parametri posmične čvrstoće diskontinuiteta, propusnost pukotinskog sustava unutar strukture lapora, hidrogeološke značajke lokacije) te negativan utjecaj ljudskih aktivnosti (izgradnja prometnica bez kvalitetnog sustava prikupljanja i odvodnje, iskopi bez odgovarajućeg ojačanja i zaštite od erozije). U prije opisanim uvjetima, glavni okidač aktiviranja klizanja bilo je smanjenje parametara čvrstoće uslijed dugog razdoblja suše i nagle infiltracije vode u pukotinski sustav uslijed kiša i topljenja snijega.
Landslide at the Bijeli Brijeg location is an active sliding with estimated dimensions of more than 100 m in length, more than 50 m in width and depth of sliding surface of D = 3 to 5 m. This is a translational block sliding in marl formation precaused by unfavorable discontinuity orientation. On the upper part of the landslide it was registered the block displacement of approximately 10 m.
The landslide is located at the slope between two local roads. The main scarp of the landslide is located at a distance of approximately 10 m from the upper road, while the foot of the landslide was buried the lower road and consequently interrupted the traffic.
Triggering factors those lead to the landslide activation were caused by many factors: geotechnical predisposition for sliding at location (slope inclination, stratification of marl sediments, bedding orientation, shear strength of discontinuities, permeability in discontinuities within the marls structure, hydrogeological characteristics at location) and negative contribution of human activity (roads constructions without quality sewage system, cut construction without adequate reinforcement and erosion protection etc.). In the above described conditions, the final triggers for sliding activation was decreasing of strength parameters of the marl rock mass caused by long drought period and sudden water infiltration in a rock discontinuity system caused by snow melting and rainfall.
This slope will never collapse again / Na ovoj kosini više nikad neće nastati klizište
Alexander Strom, Moscow, Russia
Japan. Nakon klizanja, područje glavne vlačne pukotine zaštićeno je od daljnjeg klizanja i erozije sidrenim betonskim mrežama. Neka su područja pogođena snažnim potresima koji su uzrokovali mnoga klizišta, poput potresa u središnjem dijelu pokrajine Niigata koji se dogodio 23. listopada 2003. godine ili Iwate-Miyagi Nairiu potresa koji se dogodio 14. lipnja 2008. godine. Dojam je da u tim područjima ima više ojačanih kosina nego prirodnih kosina. Na slici se može vidjeti ranije saniranu kosinu s dobro razvijenom vegetacijom u poljima na desnoj strani slike i novije saniranu kosinu na lijevoj strani slike. Može se pretpostaviti da uskoro neće ostati niti jedna prirodna padina, jer će sve biti sanirane. Zanimljivo je da japanski inženjeri ne pokušavaju ublažiti nagibe zaštićenih površina; već ih izvode tako da izgledaju umjetno, umjesto da prate prirodnu topografiju. Nakon klizanja na taj način nastaju sanirane ogoljele površine.
Japan. After landslides occur their headscarp areas are protected from further sliding and erosion by anchored concrete nets. In some areas affected by strong earthquakes that caused numerous landslides such as the 23 October 2003 Mid-Niigata Prefecture Earthquake or the 14 June 2008 Iwate-Miyagi Nairiu Earthquake, it looks that artificially protected slopes prevail over natural slopes. On this photo one can see on the right the slope reinforced earlier, with well developed vegetation in the cells and newly protected slope on the left. It can be assumed that in the near future no natural slopes will remain – all will be strengthen. It is interesting that Japanese engineers do not try to smooth the protected surface, to make it more regular – instead they follow natural topography of the bare surface that appeared after slope failure.
‘Dancing’ sticks at the Kozarice landslide near Novska / Plešući kolci na klizištu Kozarice kraj Novske
Pero Šiša, Zagreb, Croatia
Klizište Kozarice aktivirano je krajem 2004. godine na blagoj kosini nagiba 10-15°. Proces nestabilnosti pokrenut je brzo i progresivno i izazvao je značajne štete. Gornji dio klizišta je ugrozio prometnicu i zahvatio cijelu konstrukciju u širini od oko 20 metara, a što je rezultiralo prekidom prometa. Bočno se šireći, klizište je zahvatilo obiteljsku kuću, povuklo ju je niz kosinu i oštetilo je pomoćne građevine smještene niže na padini. Klizna ploha nalazi se relativno plitko na donjoj granici debelog sloja pokrivača na 3.5 m dubine; trošni slojevi prašinastih do glinovitih sedimenata na podlozi srednje do gornje pliocenske starosti. Najahivanje pokrenutog materijala u nožici klizišta debelo je 1 m, a isto je zabilježeno i na bokovima klizišta.
Trošenje i degradacija materijala na granici pokrivača i svježih ili slabo rastrošenih naslaga u podlozi, stvorilo je zonu tla s niskim rezidualnim parametrima čvrstoće. Čvrstoća ovog razmekšanog materijala dodatno je smanjena povećanjem pornih pritisaka u razdoblju obilnih oborina i topljenja snijega. Uklanjanje šume i promjena namjene zemljišta te izgradnja građevina na padini utjecala je na povećanje posmičnih naprezanja i pojavu klizanja uzduž kosine.
The Kozarice Landslide was activated at the end of 2004, on a gentle slope with inclination of 10-15°. Instability process occurred out quickly and progressively and consequently caused a significant damage. Upper part of the landslide endangered the local road, overtook approximately 20 meters of road construction and caused traffic interruption. Spreading laterally, the landslides captured a small house in construction, pull it down the slope and damaged downhill positioned utility buildings. Sliding surface is positioned relatively shallow, on the contact of the 3.5 m tick superficial deposit: weathered layer of silty to clayey sediments and the bedrock of middle to upper Pliocene age. Overriding sliding material in the landslide toe is 1 m high and it is also registered sporadically on the landslide flanks.
Weathering process and consequent degradation of materials at contact of superficial deposits and fresh or slightly weathered bedrock, created a zone of low residual strength parameters of material. The strength of this softened material was additionally decreased by increasing of pore pressures in the periods of heavy precipitations and snow melting. Deforestation, changes in land-use and new construction on the slope, significantly affected on raise of shear stresses and occurrences of sliding processes along the slope.
The Lateral scarp of the Brus landslide / Bočna pukotina klizišta Brus
Martina Vivoda, Rijeka, Hrvatska
Klizište Brus pokrenulo se 9. travnja 2005. godine u blizini sela Brus u sjevernom dijelu Istre. Taj se dio Istre sastoji od flišnih naslaga paleogenske starosti. Klizište Brus je tipično translacijsko blokovsko klizanje, a klizno tijelo se sastoji od jedinstvenog bloka flišne stijenske mase dugačkog 150 m i širokog 35 m. Klizanje se pokrenulo nakon razdoblja obilnih kiša i to vrlo brzo bez ikakvih prethodnih naznaka moguće nestabilnosti. Naslage stijena koje izgrađuju padinu na kojoj je pokrenuto klizište sastoje se od debelog paketa flišnih naslaga s izmjenom slojeva prahovnjaka i pješčenjaka. Debljina kliznog tijela je 8 do 10 metara, a klizna ploha je formirana kroz sloj prahovnjaka. Uzorci klizanja su nepovoljna orijentacija slojeva stijenske mase i erozija rijeke u nožici klizišta u kombinaciji s nepovoljnim hidrogeološkim uvjetima u kosini.
The Brus landslide occurred on 9th April 2005 and it is located near the Brus village in north part of Istria peninsula, Croatia. This area of Istria is composed of flysch deposits of Paleogene age. Landslide Brus is typical translational block sliding and landslide body consists of practically unique flysch rock mass block, 150 m long and 35 m wide. The sliding occurred after period of heavy rainfall and it was very rapid, without previous announcement signs of possible instability. Superficial deposits are made of considerable thick flysch rock mass deposit, with alternating layers of siltstones and sandstones. Thickens of landslide body is 8 to 10 m and sliding surface is formed through the siltstone layer. Unfavorable relative orientation of rock mass layers and the river erosion in the toe of the slope in combination with unfavorable hydrogeological conditions are the causes of this sliding.
Rockfall basketball / Košarka s odronom
Goran Vlastelica, Split, Croatia
Dalmacija je, osim po problemima s odronima, poznata i po košarci. Osamdesetih je godina bio najpoznatiji košarkaški tim Jugoplastike iz Splita – trostruki uzastopni europski prvak (1989.-1991.). Kao što je uobičajeno u ljudskoj prirodi, kada netko dosegne vrhunac izvedbe i savršenosti, drugi gube interes u tome. Tako izgleda da su i stanovnici Dalmacije izgubili interes za košarku. Međutim priroda je na tom području upornija. Na ovoj slici prikazan je odron na košarkaškom terenu na brdu Marjan (šumski park u gradu Splitu, Hrvatska). Teren je smješten na rasjedu koji je dugačak 4 kilometra i dijeli poluotok Marjan na pola, i to flišnu stijensku masu od karbonatne stijenske mase. Kao posljedica trošenja i erozije fliša u novijoj geološkoj povijesti, čvršća karbonatna stijena stvorila je liticu koja je na nekim mjestima visoka 15 metara. U ovom području su česti odroni, međutim relativno su mali i nezamijećeni. Odron (oko 10 m3) dogodio se 30. prosinca 2010. godine nakon jednomjesečnog kišnog razdoblja nakon kojeg je uslijedio tjedan dana s temperaturom ispod točke smrzavanja. Na sreću, tih dana nitko nije bio zainteresiran za košarku pa je odron zakucao posljednji koš na tom terenu bez gledatelja, doslovce bacajući koš na koljena.
Except of its problem with rockfalls, Dalmatia is also famous for its basketball teams. During 1980s one of the European most famous basketball team was Jugoplastika from the city of Split – three times consecutive European champion (1989.-1991.). It is usual in human natures that if someone reaches a certain peak of performance and excellence, than others lose interest in the matter. Therefore the people in Dalmatia seem to have lost their interest in basketball. However, nature itself in this region is more persistent. In this photo rockfall on a basketball court at the Marjan hill (park forest in the city of Split, Croatia) is shown. This court stands on a fault which is about 4 km long, and it slices the Marjan peninsula in half, dividing flysch rock mass from carbonate rock mass. As a consequence of flysch rock mass weathering and erosion in the recent geological history, the harder carbonate rocks formed a cliff which is at some places more than 15 meters high. In this area rockfalls are often, however usually relatively small and unnoticed. This rockfall (app. 10 m3) occurred on 30th December 2010 after one month of heavy rainfall followed by a week of very low temperatures below the freezing point. Fortunately, these days no one is interested in basketball so this rockfall scored the last point on this court without any audience, thus literally setting the basketball (hoop) on its knees.
Sannoji landslide, the best place for rice growing / Klizište Sannoji, najbolje mjesto za uzgoj riže
Fawu Wang, Shimane, Japan
Klizište Sannoji se nalazi u predgrađu grada Matsue, prefektura Shimane, Japan. To je najveće klizište u pokrajini Shimane dužine 1.500 metara, maksimalne širine 500 metara i površine 43,3 hektara. Sada je cijela površina klizišta pretvorena u rižino polje. Fotografija je napravljena u svibnju 2012. godine kada je rižino polje potopljeno i spremno za rast riže. Može se zamisliti kako je na jesen cijela površina klizišta prekrivena žutom rižom. To je mjesto odabrano kao jedno od stotinu najljepših rižinih terasa u Japanu.
Svake godine se studenti odjela geoznanosti dovode na to klizište kako bi naučili kako ljudi mogu učiniti klizište korisnim. Općenito gledano, klizište je geohazardni događaj, međutim, ako je kosina blaga i bogata vodom koja se korisno upotrebljava, klizište može doprinijeti ljudskoj sreći. Zapravo su stanovnici okolice klizišta Sannoji zadovoljni njihovim tamošnjim mirnim i slobodnim životom. Drevna Tradicionalna umjetnost plesa nazvana Sannoji kagura- sveta glazba i ples, usko je povezano sa Sada Shin Noh-om, svetim plesom u hramu Sada koji se nalazi na UNESCO-vom reprezentativnom popisu kulturne baštine.
Što se geološke građe tiče, andenzitne i riolitne piroklastične stijene tercijarane starosti leže na muljnjacima i riolitnim tufovima. Klizna ploha je formirana duž sloja muljnjaka. Za sanaciju klizišta potrošeno je više od 1,3 miljardi japanskih jena.
The Sannoji landslide is located in the suburban area of Matsue City, Shimane Prefecture, Japan. With the maximum lengthy of 1,500 m, maximum width of 500 m and the area of 43.3 ha, it is the largest landslide in Shimane Prefecture. Now, the whole landslide surface has been developed as rice paddy. The photo was taken in March, 2012 when the rice paddy is filled with water and ready for new rice growing. It can be imaged that the whole landslide area is covered with yellow rice in autumn. This site is selected as one of the hundred beautiful terrace paddy sites in Japan.
Every year, we also lead students in Department of Geoscience to this site to learn how people can make use of landslide, and how we can benefit from a landslide. Generally landslide is a geo-hazard, but when the gentle slope and rich groundwater is positively used, the landslide can contribute to human happiness. Actually, the people living around the Sannoji landslide is satisfied with their peaceful and leisure life here. The traditional performance art called Sannoji ancient kagura-sacred music and dancing, has very close relationship to the Sada Shin Noh, sacred dancing at Sada shrine, which is in the Representative List of the Intangible Cultural Heritage of Humanity of UNESCO.
For the geological condition, the andesitic and rhyolitic pyroclastic rocks in Tertiary period are overlaying on the mudstone and rhyolitic tuff. Landslide occurred along the mudstone layer. More than 1.3 billion JPY has been used for countermeasure work in this landslide.
Three people died in Tuzla’s landslide / Troje ljudi poginulo u klizanju u Tuzli
Sabid Zekan, Bosnia and Herzegovina, Tuzla
Dana 5. prosinca 2010. godine u 4:30 ujutro četvero ljudi iz obitelji Salkić ostalo je zatrpano u kliznoj masi klizišta u Tuzli. Troje ih je umrlo, a četvrti član obitelji je preživio. U 15 sati poslije podne iznijeta su beživotna tijeka Zilke (48), njezinog sina Nermina (21) i njene svekrve Safije (64). Zilkin muž Ćamil izvučen je živ ujutro.
Stručnjaci nisu očekivali klizište na tom mjestu, izgledalo je to kao vrlo stabilna kosina. Kosina je izgrađena od sloja kvarcnog pijeska koji leži na slojevima čvrste gline. U šezdesetim godina je na tom mjestu bilo pozajmište pijeska koji se koristio u podzemnim rudnicima za zatrpavanje podzemnih prostorija.
Kuća Ćamilovih stajala je u nožici kosine u području amfiteatralnog oblika. Klizanju je prethodilo razdoblje od sedam dana obilnih kiša. Sloj kvarcnog pijesak se ispunio vodom te je u ranim jutarnjim satima zatrpao kuću Ćamilovih dok je cijela obitelj spavala. Odmah nakon klizanja spasilački timovi su krenuli u spašavanje obitelji Salkić. Najbrži su bili vatrogasci, a ubrzo su stigli spasilački timovi rudara i civilne zaštite.
Four people from the Salkić family had been buried in landslide mass in Tuzla on 5th December 2010 at 4:30 am. Three of them were died, and the fourth one was survived. Lifeless bodies of Zilka (48), her son Nermin (21) and her mother in law Safija (64) had been excavated at 3:00 pm this day. Zilka’s husband Ćamil had been brought out alive in the morning.
Experts didn’t expect landslide at this place; it was looked as a very stable part of the slope. The slope is built of the quartz sand layer over the stiff clay layers. The quartz sand from abandoned borrow sand pit in the lower part of the slope was used in underground mining for closure of underground spaces in last century during 60’s.
The Ćamil’s house was built in the foot of the slope in an amphitheatrically shape morphological feature. A landslide occurrence was caused by heavy rain seven days before the sliding. The quartz sand layer was filled by water and the landslide was triggered and buried the house, while family Salkić was sleeping. Immediately after sliding, many of rescue teams came to the site to rescue the Salkić family. The fire-fighter team was the fastest one, and the mining rescue and civil protection teams came very soon.
Excessive erosion in the Slani potok catchment leads to complete devastation of the area/ Intenzivna erozija u slivu Slanog potoka vodi ka potpunoj devastaciji područja
Sunčica Željem, Zagreb, Croatia
Slika prikazuje drastičan primjer kombinacije erozijske aktivnosti i višestrukih klizanja u slivu Slanog potoka. Taj sliv je dio većeg sliva rijeke Dubračina u Vinodolskoj dolini. Vrhove doline izgrađuju karbonatne stijene, dok se kompleks flišne stijene nalazi u donjim dijelovima i u dnu doline. Flišni teren je slabo propustan pa je infiltracija vode slaba, a koeficijent otjecanja visok. Mnogi izvori i drenaže podzemne vode postoje na granici između propusnih karbonatnih stijena i nepropusnog flišnog kompleksa. Nekada kaptirani izvori uglavnom su napušteni nakon izgradnju vodovoda, a izvorska voda se u nekontroliranim razmjerima izlijeva na teren. Tijekom kišnih razdoblja formira se mreža privremenih i trajnih vodotoka rezultirajući erozijom, ispiranjem i stvaranjem vododerina što vodi ka pojavi nestabilnosti padina (klizanje i puzanje). Zbog tih je okolnosti u slivu Slanog potoka teren ogoljen i potpuno degradiran dok intenzivna erozija djeluje na flišnu stijensku masu. Hidrotehničke građevine unutar sliva su ugrožene dok su retencije uglavnom ispunjene sedimentima. Iznad središnjeg dijela bazena pojavila su se klizišta koja u kombinaciji s erozijom uzorokuju daljnju degradaciju šume i agrikulturnih površina, ugrožavajući prometnice i naselja na tom području. Tijekom posljednjih stotinjak godina područje Slanog potoka se promatra i periodično sanira.
The picture shows a drastic example of combined erosion activity and landslides occurrences in the Slani potok basin. This basin is part of the larger catchment area of the Dubračina River in the Vinodol Valley, Croatia. Carbonate rocks form tops of the valley slopes while flysch rock complex form the lower parts and the bottom of the valley. Flysch terrain is of low permeability so its water infiltration rate is low and its runoff coefficient is generally high. At the contact of the permeable carbonate rocks and impermeable flysch complex, many springs and groundwater drainages exist. Previously captioned springs are mostly abandoned after the construction of the water supply system; hence spring water is in uncontrolled manner discharged on the ground surface. During the rainy seasons, networks of temporary and permanent watercourses are formed resulting in erosion activity, by washing and formation of gullies that lead to the occurrence of slope instability (sliding and creeping). Due to this occurrences, terrain is denuded and been completely degraded while flysch rock mass is affected with excessive erosion. Hydro-technical structures in the basin are endangered while retention basins are mainly filled with sediments. Upstream from the middle part of the basin, small landslides occurred and, in combination with erosion, cause further degradation of forests and agricultural surfaces, endangering roads and settlements in the area. The Slani potok area has been studied and remediation measures were periodically conducted in the last hundred years.
Landslide protection in Rest and be Thankful, Scotland / Zaštita od klizišta u Rest and be Thankful, Škotska
Vjekoslav Budimir, Osijek, Croatia
Slika je napravljena na turističkoj lokaciji Rest and be Thankful u Škotskoj na glavnoj cesti koja vodi sjeverno od Glasgowa. Već je 2007. godine cesta bila blokirana zbog blatnog toka koji je donio oko 400 tona materijala na cestu. Novi sličan događaj uslijedio je 2009. godine te je cesta opet nekoliko dana blokirana. Čini se da je aktivnost takvih klizišta vrlo učestala, s volumenom od maksimalno 1.000 tona (što je kasnije usvojeno kao projektna masa). Nakon što su lokaciju detaljno pregledali inženjeri tvrtki Scottland Transerv i Geobrugg, odlučeno je da će se ugraditi felksibilna barijera za sanaciju plitkih klizišta dugačka 80 m kako bi tako zaštitilo cestu od budućih sličnih događaja. Tvrtka Geobrugg, kao proizvođač barijera protiv prirodnih hazarda, posljednje tri godine ulaže veliku količinu novaca u istraživačke projekte testiranja i razvoja barijera za plitka klizišta i to terenskim ispitivanjima stvarnih dimenzija barijera. Testiranje je bilo pri kraju kada se pojavio ovaj zanimljivi projekt u Škotskoj gdje se prvi puta ugradio ovaj novi sustav barijera. Brza instalacija samobušivim sidrima i mali utjecaj na krajolik su dvije osnovne prednosti nad standardnim mjerama zaštite klizišta, kao što su veliki betonski zidovi. Kao dio sustava monitoringa biti će ugrađena i dodatna oprema na pojedinim lokacijama na kosini iznad ceste. Kako bi se uočili mogući pomaci ili promjene koje mogu utjecati na pojave novih nestabilnosti, u monitoring je uključeno i povremeno lasersko skeniranje kosina.
This picture was taken at touristic place Rest and be Thankful in Scotland on the main road heading north from Glasgow. In 2007 the road was already blocked because of a mudslide coming down with 400 tons of material to the road. Next event happened in 2009 and the road was blocked again for several days. The activities of the slides seem to be quite frequently with volumes of about max. 1,000 tons (later design volume). After that people from Scottland Transerv and Geobrugg analyzed the site in detail and decided to install an 80 m long flexible shallow landslide barrier there to protect the road from further events. Geobrugg as a supplier of barriers against natural hazards mainly spend a big amount of money in a research project where they tested and developed barriers against shallow landslides with large scaled field tests over a three year period. The testing phase was nearly at the end when this interesting project came up in Scotland as one of the first application of this new barrier system. Quick installation with self-drilling anchors in the slope and a light impact to the countryside are only two main advantages to conventional measures against landslides with big footed concrete walls for example. Additional remote sensing equipment will be installed at specific locations on the slope above the road as part of ongoing monitoring. This monitoring also includes laser scanning to identify any movements or changes of concern.
The Grohovo Landslide/ Klizišta Grohovo
Martina Vivoda, Rijeka Hrvatska
Klizište Grohovo je smješteno na sjeveroistočnoj padini doline Rječine u zaleđu grada Rijeke. Taj dio doline Rječine se sastoji od vapnenaca na vrhu doline i siliciklastičnih stijena ili fliša na donjim dijelovima padine i u dnu doline. Klizna ploha nalazi se na granici između pokrivača i flišne podloge. Klizanje se dogodilo 5. prosinca 1996. godine na lokaciji starog klizišta iz 1893. godine, ali puno manjeg volumena od starog klizanja. Klizna masa u potpunosti je zatrpala korito Rječine. Nakon inicijalnog klizanja uslijedio je retrogresivni razvoj od podnožja prema vrhu padine te razvoj više manjih kliznih tijela. Na kraju procesa pomaknuti su izolirani stijenski blokovi i otvorene su pukotine u vapnencima na vrhu klizišta. To je kompleksno klizište, a granice između tijela pojedinih klizišta su jasno vidljive te predstavljaju granice između različitih tipova klizanja.
The Grohovo Landslide is located on the northeastern slope of the Rjecina River Valley outside the City of Rijeka, Croatia. This part of the Rjecina River Valley consists of the limestones situated on the top of the slopes and siliciclastic rocks or flysch material located on the lower part of the valley, including the bottom of the valley. Slip surface is positioned on the contact of surficial slope deposits and flysch bedrock. Sliding occurred on 5th December 1996 at the location of the old landslide from 1893 but with significantly smaller volume than the older landslide. The sliding mass completely buried the Rječina River channel. After the initial landslide there was a retrogressive landslide development along the slope, with the occurrence of smaller landslide bodies. At the end of the process, isolated rocky blocks were moved, and cracks in the limestone slope head were opened. It is a complex landslide and boundaries between these bodies are clearly visible and mark off different types of mass movements.
Ciprnik /Klizište Ciprnik
Marko Komac, Ljubljana, Slovenia
Osnovni pokretač klizišta u Sloveniji su kiše. U noći s 18. na 19. studenog, samo jedan dan nakon pojave debritnog toka koji je razorio selo Log pod Mangartom, dogodilo se još jedno relativno veliko klizanje samo 10 kilometara sjeverozapadno od prethodnog klizanja. Početno klizište, koje je pokrenuto u blizini vrha brda Ciprnik (na približnoj visini od 1460 metara iznad mora) u raspucanim masivnim i debelo uslojenim dolomitima karnijske starosti s proslojcima vapnenaca, postupno se razvilo u debritni tok koji se deponirao približno 400 metara niže u dolini Tamar. Na sreću, taj se događaj dogodio u noći u nenaseljenom području, pa se osim manjeg oštećenja lokalne prometnice i planinske staze, nikakve druge štete nisu dogodile. Duljina debritnog toka bila je oko 900 m i u najširem dijelu iznosi 150 metara.
Rainfall is the primary landslide triggering factor in Slovenia. In November 2000, just one day after the debris-flow event that devastated the village Log pod Mangartom, in the night of 18 to 19 November, another one relatively large event happened just 10 kilometers north-west of the first occurrence. Initial landslide that was triggered near the top of the Ciprnik hill (at approximate elevation of 1460 m a.s.l.) in the fractured massive and thick-bedded Carnian dolomite with limestone inclusions, was evolved into a debris-flow and accumulated approximately 4000 meters below in the Tamar valley. Luckily, this event happened in a non-populated area during the night and except for a smaller transport route and a mountain track no damage occurred. The length of the transport was approximately 900 meters and at its widest part, the debris-flow, spread across 150 meters.
Landslide in The Torine Quarry Landslide/ Klizište u kamenolomu Torine
Mirko Grošić, Rijeka, Croatia
Kamenolom Torine smješten je u blizini naselja Gradac Našički u istočnom dijelu Republike Hrvatske. Područje eksploatacije je izgrađeno od bazaltne stijenske ploče koja leži na flišnoj stijenskoj masi. Bazaltne ploča je debela 40 metara i leži na potpuno trošnom do jako trošnom sloju lapora. Nagib kontakta ovih geoloških jedninca je pod kutom od 15 stupnjeva prema iskopanom dijelu. Ustanovljeno je klizanje bazaltne stijenske mase s kliznom plohom kroz zonu na granici s laporom, te je utvrđeno postojanje tri različita klizišta čiji volumen iznosi 500.000 m3, 2.500.000 m3 i 75.000 m3. Na slici je prikazana jedna od pukotina u području tzv. grabena, udoline u gornjem dijelu klizišta nastale usijedanjem pokrenutog materijala.
The Torine Quarry is situated near the city of Gradac Našicki in eastern part of the Republic of Croatia. Exploitation area is made of basalt rock mass plate lying onto the flysch rock mass. The basalt plate is about 40 m thick and it is positioned on completely weathered to highly-weathered marl layer. Contact of these geological units has dip of 15o toward the exploitation area. Sliding of basalt rock mass with the sliding surface trough the contact zone was occurred and three different landslides were determinate with total volumes of 500,000 m3, 2,500,000 m3 and 75,000m3 respectively. One of the cracks in the so called graben zone in the upper part of the landslide is shown on this photo.
Erosion and landslides/ Erozija i klizišta
Snježana Mihalić Arbanas, Croatia
Sliv Slanog Potoka nalazi se u Vinodolskoj dolini, a njegova veličina iznosi 3 km2. On je dio većeg sliva, sliva rijeke Male Dubračine. Ovaj sliv karakterističan je po ekstenzivnoj eroziji popraćenoj procesima puzanja i klizanja. Erozijski procesi sprječavaju rast vegetacije, zbog čega ovdje nastaje tip reljefa koji se naziva ‘badland’ – što je jedinstvena pojava u dinarskom flišu. Akumulacijom koluvijalnih površinskih naslaga nastaju tla koja su osobito sklona intenzivnim pokretima na padinama, osobito tijekom vlažnih razdoblja i obilnih oborina, kada se često pojavljuju blatni tokovi.
Središnji dio područja Slanog potoka, koji je najjače izložen opisanim procesima, nalazi se blizu grada Grižane, i između zaseoka Kamenjak i Kostelj. Prve mjere sanacije poduzete su u razdoblju od 1920. do 1934. godine, kada je dio potoka kanaliziran, neki dijelovi područja su pošumljeni i izgrađena je retencijska brana. Procesi erozije su usporili, ali nikada nisu potpuno zaustavljeni, a erodirano područje stalno se proširuje.
The Slani Potok Catchment is placed in the Vinodol Valley and its total area is 3 km2. It is part of the Mala Dubračina Catchment. This catchment is exposed to extensive erosion followed by creeping and sliding processes. Erosional processes disable grow of vegetation, forming badland type of terrain – unique phenomenon within the Dinaridic flysch. Accumulation of a colluvial soil-like superficial deposit is especially prone to intensive slope movements, especially during wet seasons and intensive precipitation, when mud flows are often.
The middle part of the Slani Potok area, as the most exposed part to described processes, is situated near the City of Grižane and between the Kamenjak and Kostelj villages. The first remedial measures were conducted from 1920 to 1934, when the part of the creek was canalized, some parts of the area were forested and retention dams were constructed. The erosion process was slow down, but it was never stopped and eroded area is ever growing.