The Socio-Spatial Structure of a City: the Example of Zagreb

This work provides a summarized overview of select aspects, concepts and results of foreign and Croatian research into the socio-spatial structure of a city. The status of the sociospatial structure of Zagreb has been determined through an analysis of statistical indicators of the socio-economic status of its population. The results show similarities between the socio-spatial structure of Zagreb and other postsocialist cities. The spatial pattern from the pre-transition period has been retained, and it is refl ected in the declining socio-economic status of the population from the center to the peripheral sections of the city

ZNAČAJ STRUKTURNIH I GEOLOŠKIH ODNOSA U KONSTRUKCIJI PODZEMNE HIDROELEKTRANE OMBLA

The construction design of the underground hydroelectric plant Ombla required geological and structural investigations to he carried out. Due to past earthquakes in the area permanent tectonic movements were inferred. Therefore, in the wider and adjacent surroundings of the Ombla spring it was necessary to analyze the structural fabric and the geodynamic characteristics of the area. The most active zone encountered is the front part of a thrust fault belonging to the Dinaricum regional structural unit. The compressive regime is maintained as a response to the regional stress of an approximately S-N orientation. Different displacements of various parts of the Dinaricum unit are present. Along the rim of the structural blocks, the Hum-Om-bla fault zone extends, accompanied by left transcurrent faults, Through this zone the main groundwater drainage occurs supplying the Ombla spring. In the local Ombla spring area this zone is characterized by three sub-blocks and three major faults. The most important fault for the vital facilities of the Ombla hydroelectric power plant is the Pločice fault which divides the structural sub-blocks. Along this fault zone there are four mutually connected. The lowest two arc active groundwater draining systems supplying the Ombla spring. The data on local stress implies the following deformation of sub-blocks: sub-blocks 2c and 2f are displaced along normal faults from 20° to 30° to the left, downwards, while the sub-block 2 d is displaced along the Pločice thrust fault of 100° to 130° to the left, upwards. The structural data confirmed that the building of an underground dam with a height from 100 to 130 m was feasible. The connection between the caverns and the fault zone was determined. The unfavorable position of the active Pločice fault zone imposes the construction of vital Ombla power plant facilities underground.Za potrebe izgradnje podzemne hidroelektrane Ombla izvršena su i strukturno-geološka istraživanja. Zbog pojava potresa znalo se za postojanje stalne tektonske aktivnosti. Stoga se u širem i lokalnom prostoru oko izvorišta Ombla pristupilo razradi strukturnog sklopa i geodinamičkih odlika prostora. Najaktivniju zonu predstavlja čelo navlake regionalne strukturne jedinice Dinaricuma. Djelovanje regionalnog stresa približne orijentacije J-S stvara kompresijski režim. Postoje različiti pomaci dijelova jedinice Dinaricuma. Granicom strukturnih blokova proteže se zona rasjeda Hum-Ombla s prisutnim lijevim transkurentnim pomacima. Kroz tu zonu postoji glavni dovod podzemne vode na izvorište Ombla. U lokalnom prostoru unutar te zone izdvajaju se tri strukturna potbloka i tri važna rasjeda. Za vitalne objekte HE Ombla značajan je rasjed Pločice koji odvaja strukturne potblokove. Duž njegove zone u prostoru su formirana četiri povezana nivoa šupljina. Dva donja predstavljaju aktivan dovod vode na izvorište Ombla. Podaci o lokalnom stresu ukazuju na deformacije potblokova i to: potblokovi 2c i f pomiču se duž normalnih rasjeda od 20° do 30° lijevo, dolje, a potblok 2 d duž reversnog rasjeda Pločice od 100° do 130° lijevo, gore. Strukturni su podaci potvrdili mogućnost izgradnje podzemne brane visine od 100 do 130 m. Utvrđena je povezanost šupljina sa sustavima rasjeda. Nepovoljni položaj aktivne zone rasjeda Pločice u prostoru uvjetuje projektiranje vitalnih objekata HE Ombla u podzemlju

ZNAČAJ STRUKTURNIH I GEOLOŠKIH ODNOSA U KONSTRUKCIJI PODZEMNE HIDROELEKTRANE OMBLA

The construction design of the underground hydroelectric plant Ombla required geological and structural investigations to he carried out. Due to past earthquakes in the area permanent tectonic movements were inferred. Therefore, in the wider and adjacent surroundings of the Ombla spring it was necessary to analyze the structural fabric and the geodynamic characteristics of the area. The most active zone encountered is the front part of a thrust fault belonging to the Dinaricum regional structural unit. The compressive regime is maintained as a response to the regional stress of an approximately S-N orientation. Different displacements of various parts of the Dinaricum unit are present. Along the rim of the structural blocks, the Hum-Om-bla fault zone extends, accompanied by left transcurrent faults, Through this zone the main groundwater drainage occurs supplying the Ombla spring. In the local Ombla spring area this zone is characterized by three sub-blocks and three major faults. The most important fault for the vital facilities of the Ombla hydroelectric power plant is the Pločice fault which divides the structural sub-blocks. Along this fault zone there are four mutually connected. The lowest two arc active groundwater draining systems supplying the Ombla spring. The data on local stress implies the following deformation of sub-blocks: sub-blocks 2c and 2f are displaced along normal faults from 20° to 30° to the left, downwards, while the sub-block 2 d is displaced along the Pločice thrust fault of 100° to 130° to the left, upwards. The structural data confirmed that the building of an underground dam with a height from 100 to 130 m was feasible. The connection between the caverns and the fault zone was determined. The unfavorable position of the active Pločice fault zone imposes the construction of vital Ombla power plant facilities underground.Za potrebe izgradnje podzemne hidroelektrane Ombla izvršena su i strukturno-geološka istraživanja. Zbog pojava potresa znalo se za postojanje stalne tektonske aktivnosti. Stoga se u širem i lokalnom prostoru oko izvorišta Ombla pristupilo razradi strukturnog sklopa i geodinamičkih odlika prostora. Najaktivniju zonu predstavlja čelo navlake regionalne strukturne jedinice Dinaricuma. Djelovanje regionalnog stresa približne orijentacije J-S stvara kompresijski režim. Postoje različiti pomaci dijelova jedinice Dinaricuma. Granicom strukturnih blokova proteže se zona rasjeda Hum-Ombla s prisutnim lijevim transkurentnim pomacima. Kroz tu zonu postoji glavni dovod podzemne vode na izvorište Ombla. U lokalnom prostoru unutar te zone izdvajaju se tri strukturna potbloka i tri važna rasjeda. Za vitalne objekte HE Ombla značajan je rasjed Pločice koji odvaja strukturne potblokove. Duž njegove zone u prostoru su formirana četiri povezana nivoa šupljina. Dva donja predstavljaju aktivan dovod vode na izvorište Ombla. Podaci o lokalnom stresu ukazuju na deformacije potblokova i to: potblokovi 2c i f pomiču se duž normalnih rasjeda od 20° do 30° lijevo, dolje, a potblok 2 d duž reversnog rasjeda Pločice od 100° do 130° lijevo, gore. Strukturni su podaci potvrdili mogućnost izgradnje podzemne brane visine od 100 do 130 m. Utvrđena je povezanost šupljina sa sustavima rasjeda. Nepovoljni položaj aktivne zone rasjeda Pločice u prostoru uvjetuje projektiranje vitalnih objekata HE Ombla u podzemlju

Correlation of Quaternary Sediments and Tectonic Activity of the Eastern Part of the Drava River Depression

The Holocene, Upper Pleistocene and Middle Pleistocene sediments in the eastern part of the Drava depression the substratum of which is determined by the conditional EK marker Q\u27, are composed in the lower part mainly of silts and clays and in the upper part of sands. The thickest parts are about 400m. The composition of the transparent heavy minerals and the result of the paleontological treatment show that the sedimentation was in the lake or swamp with the origin of detritus from the metamorphic rocks and smaller quantity of older clastic sediments.The collected data show the quaternary tectonic activity after the sedimentation of the marker horizon Q\u27. In the area between the boundary faults of the valley, the faults of the system E.N.E. - W.S.W. (N.E. - S.W.) influenced directly the sedimentation and the folding . They were the consequence of the regional movements and stress strain behaviour of rock masses, which built the structures of the valley.As a result, the horizontal component of the left wing movement is visible along the diagonal system of faults. The vertical movements have also been determined. The greatest amplitudes were along the boundary South fault of the Drava valley, up to 350 m for the period of Middle and Upper Pleistocene, or 90 m for Upper Pleistocene only

GEOTEHNIČKI MODELI TEMELJENJA MOSTA MASLENICA

On the site of Maslenica bridge structural tectonic, geophysical and engineering geological investigations, geotechnical drilling and laboratory sample testings were performed. Maslenica anticline is characteristic for the investigated area. It is built from the limestone of Cretaceous age. The anticline has an asymmetrical form with the vergence of the axial plane towards the north. Reverse faults with recent activities are present. The recent activity was proved by the discovery of the broken stalactite with the displacement of 11 cm, whose age is 36000 years. On quite young stalactites (stalagmites) in the cave on the west side, no displacements were noticed. For the next period of 500 years the maximal possible displacement of 2.0 cm is foreseen. Smaller caves with the dimensions of 1 m3, were formed on the intersections of the reverse faults and greater joints. The canyon Novsko ždrilo was formed in the fault shear zone with tectonic transport to the right. According to the range of fracture, three characteristic types of rock masses were separated by engineering geological investigations. According to »Geomechanical classification« (RMR) the first type corresponds to II to III class, while the second type corresponds to IV class, and the third type corresponds to V class (mylonite). Because of the complexity of the terrain structure, original engineering geological bases of design have not enabled the direct application of the analysis of stress-strain behaviour. Because of that the simplified geotechnical models were done. They enabled the projecting of foundation in the rock mass and renewal of poor quality rock mass.Na lokaciji Masleničkog mosta urađena su strukturno-tektonska. geofizička i inženjerskogeološka istraživanja, istražna bušenja i laboratorijska ispitivanja uzoraka. Za istraživano područje karakteristična je Maslenička antiklinala. Izgrađena je od vapnenaca kredne starosti. Antiklinala ima asimetričan oblik s vergencijom osne ravnine prema sjeveru. Prisutni su reversni rasjedi s recentnom aktivnošću. Recentna aktivnost dokazana je nalazom presječene sige s pomakom od 11 cm, čija starost je 36000 god. Na sasvim mladim sigama u špilji na zapadnoj strani nisu uočeni pomaci. Za povratni period od 500 godina progno¬ziran je mogući maksimalni pomak veličine do 2,0 cm. Manje špilje dimenzija do 1 m3 nastale su na presjecištima reversnih rasjeda i većih pukotina. Kanjon Novsko ždrilo nastao je u zoni smicanja rasjeda s desnim tektonskim transportom. Prema stupnju razlomljenosti izdvojene su inženjerskogeološkim istraživanjem tri karakteristične sredine. Prema »Geomehaničkoj klasifikaciji« (RMR) prva sredina odgovara II, do III. klasi, druga sredina odgovara IV. klasi, a treča sredina odgovara V. klasi (milonit). Originalne inženjerskogeološke podloge nisu omogućile, zbog složenosti građe terena, direktnu primjenu u analizi odnosa naprezanja i deformacija. Zbog toga su izrađeni simplificirani geotehnički modeli. Oni su omogućili projektiranje temeljenja u stijenskoj masi i saniranja dijelova slabe kvalitete

Seismotectonically Active Zones in the Dinarides

Seismotectonically active zones are formed due to displacements of segments of the Adriatic micro-plate that differ in size and in their rate of movement, and by the resistance of the rock masses of the Dinarides. The spatial position of these zones can be determined through the locations of earthquake foci. The zones of seismotectonic activity are then correlated with the most important faults on the surface. The seismotectonically active zones are relatively steeply inclined in the shallowest 10-20 km, which is caused by the oblique contacts between the Adriatic micro-plate and the Dinarides. The zones are curved at depth in many cases, which reflects the compression of the area. Curved parts of the zones are characterised by the greatest pressures and also by the most frequent earthquakes. Mildly inclined zones reflect the reverse displacements in the area, also probably the activity on contacts between rock masses of different density, or the extension of the Adriatic micro-plate subduction. The southern part of the plate is the most active. The greatest pressures caused by these movements occur in the area between Mljet island and Dubrovnik. Therefore the majority of earthquakes, and notably the strongest ones, occur in the area between Split, Imotski, Hvar island and Dubrovnik, as well as along the Montenegro coast in a SE direction

Planiranje humanijeg grada: očekivanja studenata o korištenju bicikla i prometa u Zagrebu

Researches indicate that the use of bicycles as a means of transportation and form of recreation is increasing in cities in the world’s developed countries, and that it brings with it a humanization of urban spaces and improved quality of life. Bicycle use has rarely been the topic of scholarly interest in Zagreb or Croatia as a whole, especially among student population. Therefore, a survey was conducted among students of the University of Zagreb to gauge their expectations of bicycle use and other forms of transport in Zagreb. The questioning encompassed 238 student cyclists and 359 student non-cyclists, selected by a combination of representative and focused sampling. The results point toward significant statistical discrepancies between the two student groups in their manner of using bicycles and other means of transport. Furthermore, student expectations of the city government encompass, besides anticipated measures to improve the cycling infrastructure, a series of other measures, such as, for example, subsidies for bicycle purchases and the introduction of a public bicycle sharing system. The conclusion includes six proposals for activities aimed at increasing the number of bicycle users to be undertaken by the city government and other interested parties.Istraživanja ukazuju da je korištenje bicikla kao prijevoznog sredstva i oblika rekreacije sve učestalije u gradovima razvijenih zemalja svijeta, te da pridonosi humanizaciji gradskih prostora i podizanju kvalitete življenja. U Zagrebu i Hrvatskoj biciklistički promet i korištenje bicikla rijetko su bili predmetom znanstvenog interesa. Stoga su anketom istražena očekivanja studenata Sveučilišta u Zagrebu prema korištenju bicikla i ostalim oblicima prometa u Zagrebu. Ispitano je 238 studenata biciklista i 359 studenata nebiciklista, odabranih kombinacijom reprezentativnog i namjernog uzorka. Rezultati upućuju na značajne statističke razlike između dvije studentske skupine u načinu korištenja bicikla i ostalih prijevoznih sredstava. Nadalje, studentska očekivanja od gradskih vlast, uz očekivane mjere poboljšanja biciklističke infrastrukture, obuhvaćaju i niz drugih, primjerice subvencije za kupnju bicikla i uvođenje sustava javnih gradskih bicikala. U zaključku članka navodi se šest prijedloga za aktivnosti gradskih vlasti i ostalih zainteresiranih strana u podizanju broja korisnika bicikla

POMACI STRUKTURA I SEIZMOTEKTONSKA AKTIVNOST ZAPADNOG VELEBITA: NEKA NOVA OPAŽANJA

A permanent seismotectonic activity is present in the region of northern Velebit. Through history a number of earthquakes magnitudes of VIII° and IX° MCS are reported. In this century the most powerful earthquake of a magnitude of 5.8 occurred in 1916. The key tectonic movements that cause these earthquakes are dislocations of the Adriatic platform towards the north and the resistance of the Dinarides towards these movements. The tectonic dynamics of a structural arrangement depend on the relationship between stress and the deformation of structural units. According to the tectonic measurements performed on outcrops of major faults the following orientation of stress was obtained: from 20/25° to 200/205° in the northern Velebit region and 340 to 160° in the hinterland. Within the structural arrangement compression of space occurs which is well pronounced in the Novi Vinodolski area. Possible deformation of structures is manifested spatial diagonal reverse displacements accompanied by rotation of the structure. In the Velebit hinterland right horizontal tectonic transport was determined. In the zone of the transcurrent faull Žuta Lokva-Otočac-Bunić the spatial opening leads to the formation of pull-apart structures. Seismotectonically active zones occur in the contact region between the Adriatic platform and the Dinaridcs. Spatially its position is inclined and bent.U području sjevernog Velebita stalno je prisutna seizmotektonska aktivnost. U povijesti se više puta spominju potresi intenziteta VII° i IX° MCS. U ovom stoljeću najjači potres dogodio se 1916. godine magnitude 5,8. Ključni tektonski pokreti koji uzrokuju pojavljivanje potresa jesu pomaci Jadranske platforme prema sjeveru i odupiranje Dinarida tim pomacima. Tektonska dinamika strukturnog sklopa ovisi o odnosu stresa i deformacija strukturnih jedinica. Prema podacima terenskog mjerenja u izdancima najvažnijih rasjeda dobivena je orijen¬tacija stresa: u sjevernom Velebitu 20/25°-200/205° i u zaleđu 340-160°. U strukturnom sklopu nastaje kompresija prostora osobito izražena oko Novog Vinodolskog. Moguće deformacije struktura jesu dijagonalni reversni pomaci u prostoru uz rotaciju struktura. U zaleđu sjevernog Velebita utvrđen je desni horizontalni tektonski transport. U zoni transkurentnog rasjeda Žuta Lokva-Otočac-Bunić otvaranjem prostora oblikuju se strukture tipa pull-apart. Seizmotektonski aktivna zona pojavljuje se u prostoru dodira Jadranske platforme i Dinarida. Značajan je njezin kosi položaj u prostoru uz koncentraciju žarišta resa na dubinama do 34 km

New data on Structural Relationships in the North Dalmatian Dinaride Area

Subsurface structural relationships are presented based on gravity data and seismic reflection profiles. Reflection marker horizons and the relative positions of different rock masses and structural units have been established, and are compared with surface observations. Active zones, marked by pronounced reflection boundaries in seismic profiles, have been established, the deepest of which are connected with the Dugi Otok fault zone. Below this interface, rock masses of the Adriatic platform underthrust the Dinarides. The active underthrusting plane reaches a depth of about 17 km. In the northern part of the area under consideration, contours of upthrown rock masses at depths of 5 to 11 km have been established. The area of numerous reverse faults is particularly active, and is defined on the surface by the Obrovac-Drnis-Klis fault. Reconstruction of tectonic movements indicates that rotation of structures and dextral strike slips have occurred, particularly along this fault zone