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  • 1251.
    Sissakian, Varoujan
    et al.
    Erbil, Iraq.
    Capigian, Arsen O.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Characters and Types of Alluvial Fans in the Middleand Eastern Parts of Iraq2017Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 7, nr 3, s. 115-140Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hundreds of alluvial fans are developed and still under development in thecentral and eastern parts of Iraq. The fans are of different sizes, types, shapes   andstages, laid down by rivers, permanent streams and valleys. The composition of  the sediments of the fans differs widely depending on the source of the sediments, the depositional area, size and type of the fan. Some of the alluvial fans have typical fan forms; others are hardly recognized, especially in the field; in nature; and more specifically when the fan areas are occupied as agricultural fields and/ or are very large with very gentle gradient that hinder their occurrences.Majority of the studied alluvial fans in the studied area are not presented on geological maps. This is attributed to the fact that they are not presented on the base geological maps because they are unrecognizable in the field, mainly because they have lost their fan shapes. Others; however, are presented even on the geological map of Iraq at scale of 1:1000000.In this study, the main alluvial fans are presented and described with the reason and form of their deposition. Accordingly, different types of alluvial fans are presented and described including their coverage areas, types, number of stages, shape and constituents. This is performed through interpretation of different types of satellite images, documented field data and the experience of theauthors with their long careers and expertize in the field.

  • 1252. Sissakian, Varoujan
    et al.
    Jabbar, Mawaheb Abdul
    Iraq Geological Survey.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Development of Gulley Ali Beg Gorge in Rawandooz Area, Northern Iraq2015Inngår i: Engineering, ISSN 1947-3931, E-ISSN 1947-394X, Vol. 7, nr 1, s. 16-30Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The northern and northeastern parts of the Iraqi exhibit different types of gorges. Some of themare few kilometers in length and few hundred meters in height. The most significant gorge is theGulley Ali Bed gorge in Rawandooz area; its length is about 12.1 Km, with maximum and minimumwidths of 100 to 155 m, respectively. The water in the gorge flows in two opposite directions, fromthe north and south through two streams; they meet in the middle of the gorge, and then changethe streams direction towards west; for few kilometers before it merges in the Greater Zab River.The gorge runs within very hard thickly bedded to massive carbonate rocks, which belong to Sarmord,Qamchuqa and Bekhme formations (Cretaceous in age). To the right of the southern entrance;stands Korak anticline, whereas to the left occurs Peris anticline. To the right of the northernentrance; stands Handreen anticline, whereas to the left is Bradost anticline; represented byBalikian Mountain. The gorge is developed by continuous lateral and vertical growth of the fourmentioned anticlines, with continuous incision of both streams, Rawandooz from the north andKhlaifan from the south. Both shifted their courses, continuously

  • 1253. Sissakian, Varoujan
    et al.
    Jabbo, Basim
    Iraq Geological Survey, Baghdad.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Age Estimation of Alqosh Main Landslide, North Iraq Using Exposure Dating Method2016Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 6, nr 3, s. 163-176Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Alqosh town is located in the central part of north Iraq, along the southernlimb of Alqosh anticline, a rugged mountain with maximum elevation of 837 m(a.s.l.) in the study area. The exposed formation is Pila Spi (Eocene), it consists of thickly well bedded and hard dolostone, dolomitic limestone with some marlintercalations. The dip amount varies from (15 – 45) southwards. The southernlimb of Alqosh anticline is densely dissected by deep valleys; some of them are in canyon form. The spacing between valleys ranges from (115 – 235) m, they all run almost in straight courses downslope, with some slight meandering.Alqosh town is one of the old towns in the vicinity, it dates back to 1000years B.C. with population of about 11 000 inhabitants. In the old part of the town, the houses are built of large blocks of dolostone and dolomitic limestone quarried from the Pila Spi Formation. Due to north of the town, a large and very old landslide exists, the toe has reached the extreme northern part of the town. Tens of houses are built on the toe area; indicating that the landslide is very old. The involved area by the landslide is about 50 000 m2 with length and width of 500 m and (62 – 144) m, respectively. To estimate the age of the landslide, field work was carried out to map the toe area, check about the slid materials and to measure the size of the existing slid blocks and any other evidence of the landslide. The exposure dating method is used to estimate the age of the landslide. The old living people in the town were asked about the age of the houses that are built on the toe to estimate the age of the landslide. Moreover, the covered materials of the toe and other parts of the landslide were carefully inspected to find indications for age estimation. Some archaeological data also were used for age estimation. Depending on all available data, the age of the landslide is estimated to be about 3000 (three thousand) years.

  • 1254.
    Sissakian, Varoujan K.
    et al.
    Faculty of Geology, University of Kurdistan, Erbil .
    Abdul Ahad, Ayda
    Iraq Geological Survey, Baghdad.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Neotectonic Activity from the Upper Reaches of the Arabian Gulf and Possibilities of New Oil Fields12018Inngår i: Geotectonics, ISSN 0016-8521, E-ISSN 1556-1976, Vol. 52, nr 2, s. 240-250Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Upper reaches of the Arabian Gulf consist of different types of fine sediments including the vast Mes-opotamia Plain sediments, tidal f lat sediments and estuarine sabkha sediments. The height of the plain startsfrom zero meter and increases northwards to three meters with extremely gentle gradient. The vast plain to thenorth of the Arabian Gulf is drained by Shat Al-Arab (Shat means river in Iraqi slang language) and KhorAl-Zubair (Khor means estuary). The former drains the extreme eastern part of the plain; whereas, the latterdrains the western part. Shat Al-Arab is the resultant of conf luence of the Tigris and Euphrates rivers nearAl-Qurna town; about 160 km north of the Arabian Gulf mouth at Al-Fao town; whereas, the length of KhorAl-Zubair is about 50 km; as measured from Um Qasir Harbor. The drainage system around Khor Al-Zubair isextremely fine dendritic; whereas around Shat Al-Arab is almost parallel running from both sides of the rivertowards the river; almost perpendicularly. The fine dendritic drainage around Khor Al-Zubair shows clearrecent erosional activity, beside water divides, abandoned irrigation channels and dislocated irrigational chan-nels and estuarine distributaries; all are good indication for a Neotectonic activity in the region. These may indi-cate the presence of subsurface anticlines, which may represent oil fields; since tens of subsurface anticlinesoccur in near surroundings, which are oil fields.

  • 1255.
    Sissakian, Varoujan K.
    et al.
    University of Kurdistan, Hewler, KRG; Private Consultant Geologist, Erbil, Iraq.
    Adamo, Nasrat
    LTU team.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Badush Dam, NW Iraq: A Geological Study2018Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 8, nr 2, s. 1-15Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The river Tigris flows from Turkey towards Iraq in its northwestern part dissecting the whole Iraqi territory. During 1981– 1986 a very large earth fill dam was constructed, which is Mosul Dam impounding the flow of the Tigris River. It is the largest dam in Iraq and one of the largest in the Middle East. The geological conditions of the dam site and surroundings, however, are not suitable due to thick exposures of the Fatha Formation, which consists of marl, clay, limestone and gypsum. The gypsum and limestone beds are highly karstified causing severe problems to the dam foundation. Mosul dam suffers from serious problems due to the presence of karstified rocks; therefore, the Ministry of Irrigation in Baghdad, decided to construct a protection dam downstream of Mosul Dam; it is called Badush Dam. The geological conditions at Badush Dam site are the same as those at Mosul Dam site, which means the foundations of the dam are located on karstified rocks. Therefore, grouting works were planned and designed and it was partly performed from the beginning of the construction in 1988. The construction of the dam; however, stopped in 1991 due to the consequences of the First Gulf War. The constructed parts of the dam are (30 – 40) %. In this study, we have presented the main problems, which will cause real danger to Badush Dam, if its construction is re-started, and we have suggested many requirements to avoid any hazard that may cause the collapse of Badush Dam.

  • 1256.
    Sissakian, Varoujan K.
    et al.
    University of Kurdistan Hewler, Erbil, Iraq.
    Adamo, Nasrat
    LTU team.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Defects in Foundation Design Due to Miss-Interpretation of the Geological Data: A Case Study of Mosul Dam2017Inngår i: Engineering, ISSN 1947-3931, E-ISSN 1947-394X, Vol. 9, nr 7, s. 683-702, artikkel-id 78053Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Existing engineering problems in Mosul Dam and their background are discussed in this paper. A thorough review of the available geological reports was made. These reports covered many decades of investigations from 1953 up to the investigations performed during the construction of the dam. A large volume of geological information was accumulated during these investigations, but it is unfortunate to see that some of the basic facts were not interpreted correctly. This applies to the incorrect correlation of the encountered beds in the exploration boreholes and miss-understanding of the actual stratigraphic succession at the dam site. This misinterpretation contributed to misleading results regarding the true karst zones and the type of rocks and their thicknesses in the foundation zone and surrounding area. As a result, the dam was placed on problematic foundations consisting of brecciated and highly kartsified gypsum/anhydrite rocks and/or conglomerates in which gypsum forms the main constituent as cementing materials. Karstified beds were not recognized in some depths and were described as normal marl and/or breccias. This also added to the use of improper method of foundation treatment by adopting a deep grout curtain as the main anti-seepage measure instead of using a more positive measure by constructing a diaphragm wall. The mentioned misinterpretations are discussed here in details together with their consequences, and a more accurate picture of the geology is presented.

  • 1257.
    Sissakian, Varoujan K.
    et al.
    University of Kurdistan, Howler, KRG; Private Consultant Geologist, Erbil, Iraq.
    Adamo, Nasrat
    LTU team.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Elagely, Malik
    Private consultant, Baghdad, Iraq.
    A Comparative Study of Mosul and Haditha Dams, Iraq: Geological conditions2018Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 8, nr 2, s. 35-52Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mosul and Haditha Dams are the largest dams on the Tigris and Euphrates Rivers in Iraq, respectively. Both dams are of earthfill type and constructed on sedimentary rocks, but have different geological conditions. Both of them suffer from karstification problems. The former; however, suffers from intense karstification, which has endangered the stability of the dam and possible failure. The karstification in both sites is of different origins, types, shapes, sizes and depths, as well as in different rocks and geological formations. In Mosul Dam site, the highly dissolved gypsum beds of the Fatha Formation has formed solution type sinkholes with cavities of different shapes and sizes at different depth; attaining to about 250 m upon which the foundations of the dam are located. In Haditha Dam site, the karstification occur in the limestone beds of the Euphrates Formation, the developed sinkholes are of collapse type with regular shapes; either circular or oval apertures. The thickness of the karstified sequence in the foundations is not more 50 m. This research work is to highlight the role of the geological conditions, especially when the karstification in the safety of both dams is concerned and its effect on the foundations of the dams.

  • 1258.
    Sissakian, Varoujan K.
    et al.
    University of Kurdistan, Howler, KRG.
    Al-Ansari, Nadhir
    University of Kurdistan, Howler, KRG, Iraq and Private Consultant Geologist, Erbil, Iraq.
    Adamo, Nasrat
    LTU team.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Geology of the Euphrates River with Emphasize on the Iraqi Part2018Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 8, nr 3, s. 167-185Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Euphrates River is one of the longest rivers in Iraq with five main tributaries along its course. But without any tributary inside Iraq. The river flows from eastern highlands of Turkey then through Syria and enters into the Iraqi territory from central western part and runs westwards to the central part of Iraq and then meets with the Tigris River in the southern part. The geology of the Euphrates River’s basin is presented with emphasize on the Iraqi part. Besides, the stratigraphy of the basin, the tectonic style, main geomorphological features and minerals’ resources are presented within the basin too. Wide range of rocks; age wise are exposed in the basin, with different economic potentials at different parts of the basin. This study is a unique one, which deals with the geology of the Euphrates River’s basin. It is conducted using the most relevant updated geological data.

  • 1259.
    Sissakian, Varoujan K.
    et al.
    University of Kurdistan, Howler, KRG, Iraq and Private Consultant Geologist, Erbil, Iraq.
    Al-Ansari, Nadhir
    University of Kurdistan, Howler, KRG, Iraq and Private Consultant Geologist, Erbil, Iraq.
    Adamo, Nasrat
    LTU team.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Geology of the Tigris River with Emphasize on the Iraqi Part2018Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 8, nr 3, s. 145-166Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Tigris River is the longest river in Iraq with 5 main tributaries inside Iraq. The river flows from the Eastern highlands of Turkey then crosses the Iraqi territory from extreme north-western part to the central part then meets with the Euphrates River in the southern part. The geology of the Tigris River’s basin is presented with emphasize on the Iraqi part. Besides, the stratigraphy of the basin, the tectonic style, main geomorphological features and minerals’ resources are presented within the basin too. Wide range of rocks; age wise, are exposed in the basin, with different economic potentials at different parts of the basin. This study is a unique one, which deals with the geology of the Tigris River’s basin. It is conducted using the most relevant updated geological data.

  • 1260.
    Sissakian, Varoujan
    et al.
    Consultant Geologist, Erbil.
    Karim, Sahira
    Al-Kubaisy, Kifah
    Iraq Geological Survey.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    The Miocene Sequence in Iraq, a Review and Discussion on the Stratigraphy, Paleogeography and Economic potential2016Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 6, nr 3, s. 271-317Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Miocene Sequence (23.03 – 5.33 Ma), in Iraq has large diversity inlithofacies, biofacies, depositional environments, tectonic effect, and geographicaldistribution. The Savian movements caused development of broad and shallowbasins, which had covered large areas in the Iraqi territory, as compared with theearlier Oligocene sequence, which was characterized by great sea level dropcausing very limited depositional basins, the main intraplate basin becamenarrower due to the tilting of west Arabia.The Miocene Sequence, in Iraq includes 11 stratigraphic units, some of themhave not formation order, and these are: Serikagni, Euphrates, Ghar, DhibanAnhydrite, Jeribe, Fatha, Nfayil, Injana, Mukdadiya, Govanda Limestone and RedBed Series. However, some of these units have age that is not limited to theMiocene, they have range of either younger or older than Miocene.The main major event that had occurred during the Miocene was the changefrom the dominating marine phase in the Early Miocene to continental phaseduring the Late Miocene. This main change is attributed to the major thrusting,which occurred during the collision of the Sanandaj – Sirjan Zone with theArabian Plate. This event also is considered as the beginning of the Neotectoniceffect in Iraq. Many formations were terminated; others were started with differentlithological and depositional environments, as well as different faunalassemblages.The faunal assemblages, depositional environments, paleogeography, lithologyof each exposed stratigraphic units are reviewed and discussed. Moreover, thetectonic effect on each exposed unit in different tectonic zones is discussed too,beside the mutual relation between the exposed units.

  • 1261.
    Sissakian, Varoujan
    et al.
    Erbil, Iraq.
    Mustafa, Hawkar L.
    University of Kurdistan, Hawler, Erbil.
    Haris, Gowar H.
    University of Kurdistan, Hawler, Erbil.
    Sadiq, Sakar A.
    University of Kurdistan, Hawler, Erbil.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Landslides in Hareer Anticline, Central Northern Part of Iraq: Landslides in Hareer Anticline, Central Northern Part of Iraq2017Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, EISSN 1792-9660, Vol. 7, nr 2, s. 25-43Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

     Hareer anticline is a double plunging anticline with NW – SE trends, very strange and special hinge zone, hence its northwestern plunge is normal but towards southeast the hinge zone becomes very wide. The northeastern limb is very gentle with dip amount that ranges from (5 – 15) whereas the southwestern limb is very steep with dip amount that ranges from (45 – 85). The well bedded and very hard carbonates of the Bekhme Formation form the carapace of Hareer Mountain, with small exposures of the Qamchuqa Formation in the southwestern limb within few deeply cut valleys. The main reasons of the landslides are the presence of soft to fairly hard succession of marl and limestone in the lowermost part of the Bekhme Formation and the steeply dipping beds of the southwestern limb of Hareer anticline. The wet climate during the sliding and the gravitational forces have played significant role in triggering and acceleration of the two landslides that have moved short distance from the mountain. This is attributed to the presence of cliffs of the Khurmala and Pila Spi Formation at the end of the slope; the cliffs played as retaining walls to stop the sliding. To estimate the age of the two landslides in Hareer anticline, the Exposure Dating Method is used. The diverted and blocked valleys, the developed small alluvial fans from the slid mass and the weathering status of the rock blocks within the slid mass are used to estimate the age of the two landslides. The age is estimated to be few thousand years, which means during late Holocene.

  • 1262. Sissakian, Varoujan
    et al.
    Shihab, Ahmad
    Iraq Geological Survey.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Batin Alluvial Fan, Southern Iraq2014Inngår i: Engineering, ISSN 1947-3931, E-ISSN 1947-394X, Vol. 6, nr 11, s. 699-711Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Al-Batin alluvial fan is one of the largest alluvial fans in Iraq, especially in the Iraqi Southern Desert. Its eastern and southern limits form parts of the Iraqi – Kuwait international borders. The fan is de-posited by Wadi Al-Batin, the last apex being on the southern limits of the main wide depression formed by the active Abu Jir – Euphrates Fault Zone. The main trend of the fan is almost SW – NE. The length and the maximum width of the fan are 110.192 Km and 119.1 Km, respectively, whereas the slope along its length is 0.7ᴼ. The fan is covered by gypcrete sheet with thickness varies from (0.5 – 1.5) m. Four stages were recognized within the fan, which is dated to be Pleistocene in age. The four stages are marked by clear height differences. The deposition of the alluvial fan is highly affected by the activity of the active Abu Jir – Euphrates Fault Zone, which is represented on the surface as a wide shallow depression in which the fan is laid down by Wadi Al-Batin. The continuous deposition of the fan has affected the course of the Euphrates Formation within Hammar Marsh and also the course of Khor Al-Zubair in its upper reaches south of Al-Qurna, where the Euphrates and Tigris rivers merge together. Also there is trace of ancient dis-tributary of the Euphrates River that was flowing directly to the Arabian Gulf; through an estuary, which is abandoned and does not exist anymore.

  • 1263.
    Sissakian, Varoujan
    et al.
    Erbil, Iraq.
    Shihab, Ahmed T.
    Iraq Geological Survey.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    The Geology and Evolution of the Ga’ara Depression,Iraqi Western Desert2018Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 8, nr 1, s. 65-90Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Ga’ara

    Depression is the largest natural depression in the Iraqi Western Desert. The oldest and youngest exposed rocks in the area are of Permian and Eocene ages. Although the beds are almost horizontal in the area; towards the east, but the exposed formations on the four rims are not the same, large differences occur in ages of the exposed formations. Ga’ara Depression covers an area of about 1383 Km2, it has a rectangular shape; elongated in E – W direction. The southern rim is the highest and steepest, whereas the eastern one is the lowest with gentle slopes. The maximum and minimum elevations on the surrounding rims are 613 m and 423 m (a.s.l.), respectively. The four rims suffer from different type of mass movements. The depression is known to be a structural high and a topographic low. The structural high is confirmed by the exposure of Permian rocks, beside the presence of dense tension and shear joints; especially in the western, northwestern and southwestern sides of the depression. Those areas are also characterized by the presence of dense karst forms. The geomorphology and geology of the depression indicates that it started in development since the Oligocene Period, the area suffered from non-deposition; therefore, the whole deposited sequence above was subjected to intense erosion leading to the development of the depression and continuous retreatment of the rims, which is still active. The estimated numerical age of the nowadays depression is about 540655 years.

  • 1264.
    Sissakian, Varoujan
    et al.
    Erbil, Iraq.
    Shihab, Ahmed T.
    Iraq Geological Survey.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    New Tectonic Finding and its Implications on Locating Oilfields in parts of the Gulf Region2017Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 7, nr 3, s. 51-75Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Oilfield in southern part of Iraq, Kuwait and Saudi Arabia represent subsurface anticlines within the folded zone. Iraq forms the extreme northeastern parts of the Arabian Plate. It is divided into two main tectonic units which are Inner and the Outer Platforms. The former covers the southern and western parts of Iraq and is less affected by tectonic forces than the Outer Platform, which has, and still is, affected by tectonic compressional forces. The contact between the Inner Platform and outer Platform is delineated by the Abu Jir - Euphrates Active Fault Zone. Its northwestern extension is clearly visible while the southeastern extension is less clear since it is hidden under Quaternary sediments. The delineation of the contact in this part of the fault zone is the main scope of this study. Geophysical and different types of Digital Elevation Models, Landsat images, Quick Bird images, GIS and remote sensing techniques were used to delineate the contact, besides other relevant geological data such as the location of subsurface oil fields, structural contour maps on top of Cretaceous rocks and the drop in surface gradients represented by Al-Batin Alluvial Fan. Therefore, the contact is likely to be more precisely located. The concerned contact has regional interest, since it forms the contact between the folded and unfolded areas within the Arabian Plate. The folded area represents the existing subsurface anticlines that form oil fields in the southern part of Iraq, and Kuwait and more southwards to Saudi Arabia.

  • 1265.
    Sissakian, Varoujan
    et al.
    Erbil, Iraq.
    Sidiq, Sakar A.
    University of Kurdistan, Hawler, Erbil.
    Haris, Gowar H.
    University of Kurdistan, Hawler, Erbil.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Age Estimation of Qara Chattan Landslide, Using Exposure Dating Method, Sulaimaniyah, Northeast Iraq2017Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 7, nr 2, s. 1-23Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The northeastern part of Iraq; the Kurdistan Region is a mountainous area with rough topography that increases in relief differences and roughness towards north and northeast. Among those mountains is Pera Magroon with highest peak at elevation of 2773 m (a.s.l.) and relief difference with the southern plain of about 1000 m. Pera Magroon Mountain represents a double plunging anticline trending NW – SE; with many minor complications on both limbs. The oldest exposed rocks in the anticline belong to Late Jurassic, whereas the rocks of the Qamchuqa Formation form the carapace of the mountain. The southwestern limb is steeper than the northeastern one; almost being vertical. A very old and large landslide had occurred along the southwestern limb of Pera Magroon anticline ended near Qara Chattan village; therefore, it is called “Qara Chattan Landslide”. The landslide is a rock slide type with rectangular tongue-shaped and crescent-like toe area. The slid blocks belong to Qamchuqa Formation, range in size up to 3 m3; but the average size is about 1 m3. The Qara Chattan Slide had happened; most probably above an area that was originally an old alluvial fan. The slid mass has swiped the alluvial fan sediments as the large blocks were moving in very high speed down the slope during the sliding. However, on both sides of the landslide the remnant of the alluvial fan sediments can be seen in form of longitudinal and narrow masses; like embankments. To estimate the age of Qara Cahttan Landslide, the exposure dating method is used depending on the size, depth and length of the existing valleys, the age of the nearby landslide and alluvial fans, and historical data acquired from archaeological site. Accordingly, the age of the landslide is estimated to be few thousand years; during the Holocene.

  • 1266. Sissalkian, Varoujan
    et al.
    Ayda, Abdulahad
    Iraq Geological Survey, Baghdad.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Factors Controlling the Karstification Process in the Fatha Formation in Iraq2016Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 6, nr 3, s. 147-162Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Fatha Formation (ex-Lower Fars) is Middle Miocene of age and consistsof cyclic sediments, each ideal cycle consists of marl, limestone and gypsum.However, in the upper half part of the formation, reddish brown claystone occur in the cycles. Moreover, in the uppermost part of the formation, fine reddish brown siltstone and claystone occur in the cycles too. The formation is divided into two members depending on the lithological constituents. Lower Member and Upper Member, the former is characterised by the absence of red clastic in the cycles and presence of thick gypsum beds, whereas the latter is characterised by the presence of fine red clastic with subordinate limestone beds. The Fatah Formation covers considerable parts of the Iraqi territory,especially in the central western part and the central northern part too. In theformer area, the formation usually crops out in a horizontal beds, whereas in thelatter area; it is exposed in the limbs of anticlines and occasionally in their cores. The Fatha Formation is one of the main problematic geological formations in Iraq. Due to intense karstification, the rocks of the formation have caused severe damages to the constructed structures built on its exposure areas. This article deals with the factors controlling the karstification process in the rocks of the Fatha Formation and shade light why karstification is not distributed over all the exposure areas of the formation in Iraq. The study concluded that the main factors that control the karstification process in the Fatha Formation are lithological and tectonic factors.

  • 1267.
    Sjoberg, Lars E.
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och satellitpositionering.
    Grafarend, E. W.
    Joud, Seyed Mehdi Shafiei
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och satellitpositionering.
    The zero gravity curve and surface and radii for geostationary and geosynchronous satellite orbits2017Inngår i: Journal of Geodetic Science, ISSN 2081-9919, E-ISSN 2081-9943, Vol. 7, nr 1, s. 43-50Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A geosynchronous satellite orbits the Earth along a constant longitude. A special case is the geostationary satellite that is located at a constant position above the equator. The ideal position of a geostationary satellite is at the level of zero gravity, i.e. at the geocentric radius where the gravitational force of the Earth equals the centrifugal force. These forces must be compensated for several perturbing forces, in particular for the lunisolar tides. Considering that the gravity field of the Earth varies not only radially but also laterally, this study focuses on the variations of zero gravity not only on the equator (for geostationary satellites) but also for various latitudes. It is found that the radius of a geostationary satellite deviates from its mean value of 42164.2 km only within +/- 2 m, mainly due to the spherical harmonic coefficient J(22), which is related with the equatorial flattening of the Earth. Away from the equator the zero gravity surface deviates from the ideal radius of a geosynchronous satellite, and more so for higher latitudes. While the radius of the former surface increases towards infinity towards the poles, the latter decreases about 520 m from the equator to the pole. Tidal effects vary these radii within +/- 2.3 km.

  • 1268.
    Sollander, Joel
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska högskolan.
    Svensson, Marcus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska högskolan.
    Friktion mellan mobil vattenbarriär och mark2018Independent thesis Basic level (university diploma), 20 poäng / 30 hpOppgave
    Abstract [en]

    Översvämningar är en naturkatastrof som uppkommer vid stor variation i vattentillförsel, exempelvis vid regn eller snösmältning. Detta är ett problem som man länge har bekämpat genom att bygga upp barriärer för att hålla vattnet borta. Tidigare har barriärerna vanligen byggts av sandsäckar, men under de senaste decennierna har många alternativ utvecklats för att göra uppbyggandet enklare och effektivare. Geodesign Barriers AB är ett företag som utvecklat mobila vattenbarriärer med syftet att vara snabba och enkla att montera samt platseffektiv när den inte används. Barriären är utvecklad för att kunna klara stora vattentryck, men vissa markförhållanden ställer högre krav på konstruktionen. Därför har man utvecklat två komplement som ökar barriärens kapacitet. Det ena är förankringsstag som förankras i marken och det andra är en skopa som monteras på barriärens undersida. Syftet har varit att med hjälp av tester i fält, ta reda på när respektive komplement bör användas på den undersökta modellen EUR125.

  • 1269.
    Spets, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Atthammar, Sofia
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Sättningar och portryck i sulfidjord: En jämförelse mellan uppmätta värden och simuleringar i Plaxis 2D2017Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
  • 1270.
    Springman, Sarah
    et al.
    Institut für Geotechnik, ETH Zürich.
    Laue, JanInstitut für Geotechnik, ETH Zürich.Seward, Linda
    Physical Modelling in Geotechnics: proceedings of the 7th International Conference on Physical Modelling in Geotechnics 2010 (ICPMG 2010) Zurich, Switzerland, 28 June-1 July 20102010Collection/Antologi (Fagfellevurdert)
  • 1271.
    Springman, Sarah M.
    et al.
    Institute for Geotechnical Engineering, Eidgenossische Technische Hochschule Zurich.
    Laue, Jan
    Institute for Geotechnical Engineering, ETH Zürich.
    Askarinejad, Amin
    Institute for Geotechnical Engineering, ETH Zürich.
    Gautray, J.N.F.
    Institute for Geotechnical Engineering, ETH Zürich.
    On the Design of Ground Improvement for Embankments on Soft Ground2012Inngår i: Ground improvement & ground control: transport infrastructure development and natural hazards mitigation : ICGI - 2012, Research Publishing , 2012, Vol. 1, s. 67-83Konferansepaper (Fagfellevurdert)
  • 1272.
    Springman, Sarah M
    et al.
    Institute of Geotechnical Engineering, ETH Hönggerberg, Zürich, Swiss Federal Institute of Technology, Zurich.
    Laue, Jan
    Swiss Federal Institute of Technology, Zurich.
    Boyle, Richard
    Swiss Federal Institute of Technology, Zurich.
    White, Josh
    Golder Associates, Perth.
    Zweidler, Adi
    Swiss Federal Institute of Technology, Zurich.
    The ETH Zurich geotechnical drum centrifuge2001Inngår i: International Journal of Physical Modelling in Geotechnics, ISSN 1346-213X, Vol. 1, nr 1, s. 59-70Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new 2.2 m diameter drum centrifuge with a maximum acceleration level of 440 g has been installed at the Institute of Geotechnical Engineering of the Swiss Federal Institute of Technology in Zurich (Eidgenossiche Technische Hochschule: ETHZ). Twin concentric shafts allow separate control of a central tool table and a drum channel. Together with multipurpose actuator units, which can be fitted to the tool table, radial, circumferential and vertical control of construction processes or test activities may be achieved. Control and data acquisition systems are provided in modular form, allowing a flexible choice of sampling and recording modes. The development of the facility, the additional accessories required and the first geotechnical centrifuge test are described.

  • 1273.
    Springman, Sarah M
    et al.
    Institute of Geotechnical Engineering, ETH Hönggerberg, Zürich, Institute for Geotechnical Engineering, ETH Zurich.
    Laue, Jan
    Institute for Geotechnical Engineering, ETH Zurich.
    Gautray, Jean
    Institute for Geotechnical Engineering, ETH Zurich.
    Askarinejad, Amin
    Institute for Geotechnical Engineering, ETH Zurich.
    Ground improvement for embankments on soft ground2014Inngår i: Institution of Civil Engineers. Proceedings. Ground Improvement, ISSN 1755-0750, Vol. 167, nr 3, s. 149-161Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Constructing embankments on soft ground to adhere to the requirements of modern codes of practice is challenging without ground improvement. An overview is presented on the types of columnar inclusions and embankment base reinforcement in terms of load–settlement behaviour, together with calculation procedures using partial safety factors. These are based on the Swiss Code 267, Switzerland's national annex to Eurocode 7; they are relevant in the project phase and in understanding the general behaviour of the whole system. Three-dimensional inclusions have been incorporated in a two-dimensional slip circle analysis. Simple assumptions are validated against a physical model for the serviceability limit state, with good agreement. First design approximations may therefore be calculated in this way.

  • 1274.
    Springman, Sarah M.
    et al.
    IInstitute for Geotechnical Engineering, ETH Zürich.
    Laue, Jan
    Institute for Geotechnical Engineering, ETH Zürich.
    Herzog, Ralf
    Institute for Geotechnical Engineering, ETH Zürich.
    El-Hamalawi, Ashraf
    Civil and Building Engineering School, Loughborough University.
    The evolution of a physical modelling course over two decades2014Inngår i: Physical Modelling in Geotechnics: Proceedings of the 8th International Conference on Physical Modelling in Geotechnics 2014, ICPMG 2014, 2014, Vol. 1, s. 433-439Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The "Modelling in Geotechnics" course was created in 1996 and was delivered in the final year of diploma studies in civil engineering at ETH Zürich. The principles of modelling were presented and discussed with reference to aspects of physical, constitutive and numerical modeling. This was followed by a series of applications to demonstrate that models can deliver a fast track to developing engineering judgement for promoting optimal geotechnical design, without the concomitant damage that occurs due to real failures, as long as the model is suitable and adheres to the requisite scaling laws. This course is now entitled 'Physical Modelling in Geotechnics' and has seen a significant rise in enrolment. A wide-ranging set of notes was developed at the beginning. These have since been extended, together with an in-house Geotechnical Information Platform GEOTip, which provides the virtual environment for documentation and exchange of ideas. © 2010 Taylor & Francis Group, London.

  • 1275.
    Spross, Johan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    A Critical Review of the Observational Method2014Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Building a sustainable structure in soil or rock that satisfies all predefined technical requirements implies choosing a rational and effective construction method. An important aspect is how the performance of the structure is verified. For cases when the geotechnical behaviour is hard to predict, the existing design code for geotechnical structures, Eurocode 7, suggests the so-called “observational method” to verify that the performance is acceptable. The basic principle of the method is to accept predefined changes in the design during construction, in order to accommodate the actual ground conditions, if the current design is found unsuitable. Even though this in theory should ensure an effective design solution, formal application of the observational method is rare. It is therefore not clear which prerequisites and circumstances that must be present for the observational method to be applicable and be the more suitable method.

    This licentiate thesis gives a critical review of the observational method, based on, and therefore limited by, the outcome of the performed case studies. The aim is to identify and highlight the crucial aspects that make the observational method difficult to apply, thereby providing a basis for research towards a more applicable definition of the method. The main topics of discussion are (1) the apparent contradiction between the preference for advanced probabilistic calculation methods to solve complex design problems and sound, qualitative engineering judgement, (2) the limitations of measurement data in assessing the safety of a structure, (3) the fact that currently, no safety margin is required for the completed structure when the observational method is applied, and (4) the rigidity of the current definition of the observational method and the implications of deviations from its principles.

    Based on the review, it is argued that the observational method can be improved by linking it to a probabilistic framework. To be applicable, the method should be supported by guidelines that explain and exemplify how to make the best use of it. The engineering judgement is however not lost; no matter how elaborate probabilistic methods are used, sound judgement is still needed to define the problem correctly. How to define such a probabilistic framework is an urgent topic for future research, because this also addresses the concerns regarding safety that is raised in the other topics of discussion.

  • 1276.
    Spross, Johan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Toward a reliability framework for the observational method2016Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Constructing sustainable structures in rock that satisfy all predefined technical specifications requires rational and effective construction methods. When the geotechnical behaviour is hard to predict, the Euro­pean design code, Eurocode 7, suggests application of the observational method to verify that the performance is acceptable. The basic principle of the method is to accept predefined changes in the design during con­struction to comply with the actual ground conditions, if the current de­sign is found unsuitable. Even though this in theory should ensure an effective design solution, formal application of the observational method is rare.

    Investigating the applicability of the observational method in rock en­gineering, the aim of this thesis is to identify, highlight, and solve the aspects of the method that limit its wider application. Furthermore, the thesis aims to improve the conceptual understanding of how design deci­sions should be made when large uncertainties are present.

    The main research contribution is a probabilistic framework for the observational method. The suggested methodology allows comparison of the merits of the observational method with that of conventional design. Among other things, the thesis also discusses (1) the apparent contradiction between the preference for advanced probabilistic calculation methods and sound, qualitative engineering judgement, (2) how the establishment of limit states and alarm limits must be carefully considered to ensure structural safety, and (3) the applicability of the Eurocode defini­tion of the observational method and the implications of deviations from its principles.

  • 1277.
    Spross, Johan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Johansson, Fredrik
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    When is the observational method in geotechnical engineering favourable?2017Inngår i: Structural Safety, ISSN 0167-4730, E-ISSN 1879-3355, Vol. 66, s. 17-26Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The observational method in geotechnical engineering is an acceptable verification method for limit states in Eurocode 7, but the method is rarely used despite its potential savings. Some reasons may be its unclear safety definition and the lack of guidelines on how to establish whether the observational method is more favourable than conventional design. In this paper, we challenge these issues by introducing a reliability con­straint on the observational method and propose a probabilistic optimi­sation methodology that aids the decision-making engineer in choosing between the observational method and conventional design. The method­ology suggests an optimal design after comparing the expected utilities of the considered design options. The methodology is illustrated with a practical example, in which a geotechnical engineer evaluates whether the observational method may be favourable in the design of a rock pillar. We conclude that the methodology may prove to be a valuable tool for deci­sion-making engineers’ everyday work with managing risks in geotech­nical projects.

  • 1278.
    Spross, Johan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Johansson, Fredrik
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    On the use of pore pressure measurements in safety reassessments of concrete dams founded on rock2013Inngår i: Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, ISSN 1749-9518, E-ISSN 1749-9526, Vol. 8, nr 2, s. 117-128Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In probabilistic stability analyses of concrete dams founded on rock, the uplift pressure is often a parameter of major importance. In previous literature, it has been suggested that assessing uplift with pore pressure measurements, instead of using empirical assumptions, could improve the calculated dam safety. This paper presents a coherent methodology to investigate whether incorporating pore pressure measurements has any impact on the calculated dam safety, based on Bayesian linear regression of pore pressure data in combination with series-system and the first-order reliability method. The study concludes that the probability of sliding failure is closely related to the probability of an extreme increase in uplift. Hence, measured uplift should only be incorporated while this probability remains sufficiently small, which requires proper programs both for uplift monitoring and for maintenance of drains and grout curtains.

  • 1279.
    Spross, Johan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Johansson, Fredrik
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Reducing uplift pressure uncertainty with measurements under concrete dams2013Inngår i: Proceedings ICOLD 2013 International Symposium, Denver: US Society on Dams , 2013, s. 2551-2560Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In quantitative risk analyses of concrete dams founded on rock, it is necessary to consider the uplift pressure in the foundation with respect to both mean value and variation. With a more accurately predicted uplift pressure, the calculated probability of failure of the dam can be reduced. This paper proposes a methodology for predicting the current uplift pressure and related uncertainty, based both on pore pressure measurements and on expert judgment. An illustrative example is presented and the suggested methodology is compared with other conceivable approaches. The results are found to be reasonable in most conditions. However, it should be recognized that in risk analyses of dams, more extreme load cases not captured by the measurements also must be considered.

  • 1280.
    Spross, Johan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Johansson, Fredrik
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Tillståndsbedömning av betongdammar grundlagda på berg med observationsmetoden2013Inngår i: Bygg & teknik, ISSN 0281-658X, nr 1, s. 83-87Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    Observationsmetoden erbjuder ett alternativ till dagens mer etablerade dimensioneringsmetoder för geokonstruktioner. På Avdelningen för jord- och bergmekanik på Kungliga Tekniska högskolan (KTH) pågår för tillfället ett forskningsprojekt om när och i vilka typer av projekt som denna metod kan vara lämplig att använda, då man bygger i och på berg. Nu påbörjar vi ett delprojekt som syftar till att undersöka om och hur observationsmetoden kan tillämpas vid tillståndsbedömning av betongdammar grundlagda på berg, som ett led i att utveckla förvaltningen av Sveriges bestånd av dammar. Projektet finansieras av Svenskt Vattenkraftcentrum (SVC), Stiftelsen Bergteknisk forskning (BeFo) och Formas.

  • 1281.
    Spross, Johan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Johansson, Fredrik
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Stille, Håkan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Towards an improved observational method2014Inngår i: Rock Engineering and Rock Mechanics: Structures in and on Rock Masses - Proceedings of EUROCK 2014, ISRM European Regional Symposium, Taylor & Francis Group, 2014, s. 1435-1440Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The observational method is today an accepted method in Eurocode 7 for design of geotechnical structures. However, case studies with formal application of its principles are still rare. One reason could be that the method to some extent is considered complex and associated with low safety margins. In fact, the Eurocode does not give any reference to how the safety of the completed structure can be assured. This paper strives to open up a discussion on how the observational method can be improved by including a requirement for a safety margin of the completed structure. A methodology is outlined and illustrated with a simple calculation example analysing the safety of a square rock pillar. Lastly, the compatibility with the observational method is discussed.

  • 1282.
    Spross, Johan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Johansson, Fredrik
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Uotinen, Lauri K.T.
    Department of Civil and Environmental Engineering, Aalto University.
    Rafi, Jalaleddin
    BGC engineering Inc.
    Using observational method to manage safety aspects of remedial grouting of concrete dam foundations2016Inngår i: Geotechnical and Geological Engineering, ISSN 0960-3182, E-ISSN 1573-1529, Vol. 34, nr 5, s. 1613-1630Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    As concrete dams age, the need for remedial grouting to reduce the seepage and uplift pressure in the rock foundations under them increases. Based on a case study of a Swedish dam with very low calculated safety against sliding, this paper discusses the application of the observational method (as defined in Eurocode 7) to manage safety aspects during remedial grouting. The studied case was complex in that grouting works posed the risk of causing increased uplift pressure, which could have induced sliding failure along a shallow, persistent, horizontal rock joint in the foundation. The approach applied in the studied case mainly followed the principles of the observational method, except in some highly significant safety aspects for which alternative procedures are suggested and discussed. Implementing these procedures along with the observational method offers a coherent framework to manage the safety aspects of the remedial grouting of concrete dam foundations that is in line with modern risk-informed dam safety policies.

  • 1283.
    Spross, Johan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    On the observational method for groundwater control in the Northern Link tunnel project, Stockholm, Sweden2014Inngår i: Bulletin of Engineering Geology and the Environment, ISSN 1435-9529, E-ISSN 1435-9537, Vol. 73, nr 2, s. 401-408Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    For tunnelling in rock in Sweden, the public authorities usually set stringent requirements on low groundwater inflow to the tunnel, to minimise the risk of building settlement and the environmental impact. To improve this groundwater control, the potential application of the observational method in this matter was studied. A comparison was made between the actual implementation of groundwater control in the Northern Link road tunnel project in Stockholm and the definition of the observational method in Eurocode 7. The results showed that the groundwater control in the Northern Link project mainly agreed with the Eurocode. The significance of the deviations was discussed, and it was concluded that adopting the observational method for groundwater control so that it complied with Eurocode 7 would mostly entail simply a formalisation of today's procedures.

  • 1284.
    Spross, Johan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Lizka, Hana
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Observationsmetodens tillämpning på inläckande grundvatten i bergtunnlar – Fallstudie: Norra länken i Stockholm2012Inngår i: Bergmekanikdag 2012 - Föredrag / [ed] Eva Friedman, 2012, s. 89-100Konferansepaper (Annet vitenskapelig)
  • 1285.
    Spross, Johan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Olsson, Lars
    Geostatistik AB.
    Hintze, Staffan
    NCC.
    Stille, Håkan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Geotekniska risker kan hanteras bättre2016Inngår i: Bygg och teknik, ISSN 0281-658X, Vol. 108, nr 1, s. 63-66Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 1286.
    Spross, Johan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Olsson, Lars
    Geostatistik AB.
    Hintze, Staffan
    NCC.
    Stille, Håkan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Hantering av geotekniska risker i byggprojekt: Ett praktiskt tillämpningsexempel2015Rapport (Annet vitenskapelig)
    Abstract [sv]

    Skador till följd av utfall av negativa geotekniska risker kostar stora summor för svensk byggindustri. Det krävs därför en effektiv och transparent riskhantering som kan minska kostnaderna. I dagsläget används sällan de verktyg som finns tillgängliga för riskhantering fullt ut i byggprojekten.

    Denna rapport visar hur ett sådant verktyg, Svenska Geotekniska Föreningens metodbeskrivning för geoteknisk riskhantering (SGF Rapport 1:2014), kan användas i praktiken. Vi ger ett omfattande illustrativt exempel på hur riskhantering kan utföras i alla skeden av ett typiskt geotekniskt projekt från idéfas till driftskede. Exemplet är fingerat men baserar sig på schakt och grundläggning till utbyggnaden av Hästsportens hus vid Solvalla travbana från 1992.

    Det är vår uppfattning att metodiken i SGF Rapport 1:2014 är tillämpbar på alla skeden i byggprocessen, från idéfas till driftfas, i både stora och små projekt. Det är dock avgörande att riskhanteringen anpassas till varje nytt projekt eller projektskede. Det strukturerade arbetssättet som metodiken ger höjer kvalitén på riskhanteringen jämfört med ett ad hoc-betonat arbetssätt, som man ofta ser i dagens projektstyrning.

    Med tanke på denna höjda kvalitet menar vi att riskkostnaderna kan bli mindre. En absolut grund för detta är dock att man uppfyller de fyra baskraven. Dessa syftar dels till att skapa och upprätthålla en kultur där man är medveten om risker som finns hur de påverkar projektet, dels till att definiera och tydliggöra riskhanteringen inom organisationen så att inget faller mellan stolarna. Därför är det viktigaste kravet att den som bestämmer har en medveten risksyn.

  • 1287.
    Spross, Johan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Olsson, Lars
    Geostatistik AB.
    Hintze, Staffan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Vägtekniks laboratorium.
    Stille, Håkan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Would risk management have helped? – A case study2015Inngår i: Geotechnical safety and risk V / [ed] T. Schweckendiek, A.F. van Tol, P. Pereboom, M.Th. van Staveren, P.M.C.B.M. Cools, Amsterdam: IOS Press, 2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    To reduce the costs of unexpected geotechnical events in construction projects in Sweden, the Swedish Geotechnical Society has adopted a general methodology for risk management. In this paper, we exemplify how the proposed risk management philosophy could have been applied on a sheet-pile wall, which failed in 1992 in Stockholm because the design did not consider the complex site conditions. Focusing on the design phase, we discuss how geotechnical risks may be managed effectively as a natural part of the engineer’s everyday work.

  • 1288.
    Spross, Johan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Olsson, Lars
    Geostatistik AB, Tumba, Sweden..
    Stille, Håkan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    The Swedish Geotechnical Society's methodology for risk management: a tool for engineers in their everyday work2018Inngår i: Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, ISSN 1749-9518, E-ISSN 1749-9526, Vol. 12, nr 3, s. 183-189Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Swedish Geotechnical Society has adopted a general methodology for risk management in geotechnical engineering projects to reduce the costs related to negative outcomes of geotechnical risks. This technical note highlights the main features of the methodology and strives to inspire the international geotechnical community to apply sensible risk management methods. In the authors' opinion, a successful geotechnical risk management needs to be structured, be tailored to the project, and permeate the engineers' everyday work. Then, sufficient quality can be achieved in the project with larger probability.

  • 1289.
    Stille, Björn
    et al.
    Chalmers.
    Stille, Håkan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Gustafson, Gunnar
    Chalmers.
    Kobayashi, Shinji
    Experience with the real time grouting control method2009Inngår i: Geomechanik und Tunnelbau: geomechanics and tunnelling, ISSN 1865-7362, Vol. 2, nr 5, s. 447-459Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new concept of "real time grouting control method" is described by which grout penetration and grouting control are made applicable in real time by applying theories for grout spread. The stop criterion with this method can be related to achieved grout spread, and grouting may be considered complete when the grout penetration for the smallest fracture to be sealed is above a predetermined target value, or before the grout penetration for the largest fracture aperture reaches a certain maximum limiting value. It might also be possible by online monitoring of the process to predict the course of the grout spread and flow and to analyse the risk of uplift and jacking. Four tunnel projects in Sweden are presented in the paper. These references indicate that the real time grouting control method may be applicable to real grouting design and control.

  • 1290. Stille, Björn
    et al.
    Stille, Håkan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Gustafson, Gunnar
    Chalmer.
    Kobayashi, Shinji
    Experiences with real time grouting control method2010Konferansepaper (Annet vitenskapelig)
  • 1291.
    Stille, Håkan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Geological Uncertainties in Tunnelling - Risk Assessment and Quality Assurance2017Inngår i: Sir Muir Wood Lecture 2017, The International Tunnelling and Underground Space Association , 2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Risk is always present in rock tunnelling. The uncertainties connected to design and execution, especially geological uncertainties, are larger and to some degree different from those in other types of civil engineering projects. This implies that systems for handing the uncertainties like ISO 31 000 “Risk management –Principles and guidelines” must be adapted to the special conditions prevailing in underground projects. Risk management is, consequently, closely connected to project management. The work can be carried out in different ways in relation to the complexity of the project. However, site organizations with teams responsible for the geotechnical and geological follow-up is an important part of risk management in tunnelling. The project manager must have the overall responsibility.

    The uncertainties have to be treated as an integrated part with a set of activities within the project work and the ordinary project organization. Project models like Props, developed by Ericsson Infocom based on tollgates and milestones, are also very adequate.

    The base for risk evaluation should be the epistemic nature of geological uncertainties. Updating by observation and investigation can reduce the uncertainties. Systematic approaches for collecting additional information should be implemented. Lead-time to make adequate decisions may be obtained by identifying and looking for warning bells. In many situations such an approach will prevent unwanted events, like tunnel collapse, high water ingress and similar problems from happening.

    Rock design is affected by geological uncertainties. Models and material properties of the rock mass will have a much higher degree of uncertainty than other building material like concrete and steel. This implies that verification of the design cannot only be built on calculations as normal in civil engineering. The observational approach in tunnelling will therefore in most cases be mandatory and can be regarded as part of the risk assessment and quality control. A common approach in tunnel design is the adoption of prescriptive measures. Application of rock classification systems belongs to this category. The limitations of such approach need to be understood in order to achieve an adequate risk treatment.

    The overall quality is governed by two factors “doing the right things” and “doing the things right”. The special focus on the first issue comes from the special uncertainties connected to underground works. The system is called “Dual quality system”. Geotechnical category as defined in the new Euro Code (EC7) is an essential part in applying a dual quality system but it has to be adapted to rock engineering problems.

    The above described approach for risk assessments and quality assurance in rock engineering and tunnelling is based on experiences from tunnel projects and supported by theories of uncertainties.

  • 1292.
    Stille, Håkan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Presentation av det internationella kommittéarbetet som pågår med revidering av Eurocode 72013Konferansepaper (Annet vitenskapelig)
  • 1293.
    Stille, Håkan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Rockgrouting in tunnel construction: models and design2012Konferansepaper (Fagfellevurdert)
  • 1294.
    Stille, Håkan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Gustafson, Gunnar
    Chalmers.
    Dalmalm, Thomas
    Stoppkriterier vid injektering2005Konferansepaper (Annet vitenskapelig)
  • 1295.
    Stille, Håkan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Gustafson, Gunnar
    Chalmers.
    Hässler, Lars
    Application of new theories and technology for grouting of dams and foundations on rock2012Inngår i: Geotechnical and Geological Engineering, ISSN 0960-3182, E-ISSN 1573-1529, Vol. 30, nr 3, s. 603-624Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Permeation grouting is used to improve rock conditions under dams and foundations. During recent decades, there has been a substantial increase of understanding of the mechanism behind grout spread in fractured rock. It is the penetrability of the grout mix and the spread in the joints which will be the governing factors for the quality of the grout curtain. The flow properties and the pressure will give the required time to achieve the quality. The empirical based refusal and completion criteria of today can be replaced by a more engineering based grouting process. An active control method has been developed in order to govern the grout spread during the grouting operation based on the new theory of spreading of grout. The concept is called the "real time grouting control method". The concept and the latest finding of the mechanism of spreading of the grout in the fractures of the rock mass are presented in the paper. The application of the method on two dam projects is also presented.

  • 1296.
    Stille, Håkan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Holmberg, Mats
    Deformationsmätningar och observationsmetoden: Exempel från Strenger tunneln2008Inngår i: Bergmekanikdag 2008: föredrag vid Bergmekanikdag i Stockholm, 2008Konferansepaper (Annet vitenskapelig)
  • 1297.
    Stille, Håkan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Holmberg, Mats
    En tillämpning av bayesiansk statistik för kontroll av tjockleken på sprutbetongförstärkning2006Konferansepaper (Annet vitenskapelig)
  • 1298.
    Stille, Håkan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Holmberg, Mats
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Examples of applications of observational method in tunnelling2010Inngår i: Geomechanik und Tunnelbau: geomechanics and tunnelling, ISSN 1865-7362, Vol. 3, nr 1, s. 77-82Artikkel i tidsskrift (Fagfellevurdert)
  • 1299.
    Stille, Håkan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Holmberg, Mats
    Observational Method in Rock Engineering2008Konferansepaper (Fagfellevurdert)
  • 1300.
    Stille, Håkan
    et al.
    KTH, Tidigare Institutioner, Byggvetenskap.
    Holmberg, Mats
    Olsson, Lars
    Sannolikhetsbaserad dimensionering av berganläggningar med samverkan mellan berg och förstärkning / Probabilistic approach to the design of underground structures taking interaction between rock mass and rock support into account2004Konferansepaper (Annet vitenskapelig)
23242526272829 1251 - 1300 of 1474
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