Koralmbahn Baulos 60.3 St. Kanzian – Herausforderungen für den Spezialtiefbau bei extrem schwierigen Untergrundbedingungen (Seeton)/Koralmbahn lot 60.3 St. Kanzian – Challenges for special foundation works under extremely difficult ground conditions (lacustrine clay)

Bauingenieur ◽  
2019 ◽  
Vol 94 (07-08) ◽  
pp. 266-275
Author(s):  
Christoph Deporta ◽  
Andreas Körbler

Zusammenfassung Im Zuge der Errichtung der Koralmbahn wurden im Teilbereich Mittlern – Althofen, beim Baulos 60.3 St.Kanzian die Tunnel Srejach und Untersammelsdorf mit einer Länge von 620 m und 665 m errichtet. Dafür waren umfangreiche Spezialtiefbauarbeiten in extrem herausforderndem Untergrund, bestehend aus schluffigen bis feinsandigen Stillwassersedimenten („Seetone“), notwendig. Basierend auf den Erkenntnissen der umfangreichen Vorversuche des Bauherrn sowie dank innovativer Technik, konnten die Anforderungen an die Düsenstrahlsäulen (DS-Säulen-Bodenvermörtelung mit dem Düsenstrahlverfahren) hinsichtlich Durchmesser, Festigkeit, Rücklaufmenge und -behandlung erfolgreich eingehalten werden. Die im Zuge der Vorversuche getesteten und schlussendlich auf der Baustelle umgesetzten technologischen Weiterentwicklungen können als richtungsweisend für die Weiterentwicklung des Düsenstrahlverfahrens angesehen werden. Bei dem Projekt wurde zusätzlich besonderes Augenmerk auf die Qualitätssicherung gelegt. In einem eigens im Zuge der Baustelle entwickelten Programm wurden alle produktionsrelevanten Daten elektronisch in einer SQL-Datenbank zusammengefasst, täglich ausgewertet und die Ergebnisse dieser Auswertung graphisch dargestellt. Dadurch konnten die Arbeiten mit verhältnismäßig geringem Aufwand mehrfach überprüft werden.

Author(s):  
Artem Lapenkov ◽  
Artem Lapenkov ◽  
Yury Zuyev ◽  
Yury Zuyev ◽  
Nadezhda Zuyeva ◽  
...  

Coastal zones have great diversity of resources. The shallow water zones contain the most of plant and benthic communities. A description of relief and type of ground is needed for the rigorous monitoring of biota and environmental condition of coastal zone. Generally, on the basis of these data the investigation methods of the coastal zone are selected. The shallows research strategy has been developed by us for northern part of the Lake Ladoga. If the coastal areas are characterized by great depth and flat topography, then sonar’s can be used to describe them and samples of ground can be taken by bottom grabs. In the Lake Ladoga these methods don’t operate correctly by reason of the compound bottom relief and the fact that a sizeable part of the bottom is occupied by hard ground. Therefore, our investigations base on the diving transect method of Golikov and Skarlato (1965). A diver moves along transects. He registers the depth, length to coastline, water temperature, relief and ground, edificators and records video. In the laboratory all these data are decoded and used for mapping of bays. Studies of plant communities have been performed and strategy for research of benthic communities in complex relief and hard ground conditions has been developed based on the descriptions of shallow waters. Description of the Malay Nikonovskia Bay bottom has given an opportunity to estimate changes in the bottom of the bay under the influence of the trout farm.


Author(s):  
Anne Lemnitzer

We are excited to present the work of five excellent author groups who prepared the research papers and case studies featured in this Issue. Three of the five papers deal with piles and the remaining two papers involve foundation construction on soft ground conditions.


The Auk ◽  
2005 ◽  
Vol 122 (1) ◽  
pp. 71-81 ◽  
Author(s):  
Alexander M. Mills

AbstractProtandry, the earlier arrival of males than of females on breeding areas, occurs in many taxa, including many migratory birds. Numerous hypotheses have been generated to explain protandry. Using bird-banding records, I show that protogyny, the earlier migration of females, frequently occurs in the autumn, though it is less universal and less dramatic than spring protandry. In one species, it occurs in both hatch-year and adult birds. When (1) spring and autumn, (2) departures and arrivals, and (3) breeding and wintering ground conditions are considered, hypotheses generated only to explain spring protandry can be more thoroughly evaluated. Using that approach, the most parsimonious explanation of differential migration between the sexes explains earlier male arrival in spring and later male departure in autumn through either (1) indirect selection operating on intrasexual male competition for territories or (2) direct selection operating on intersexual relations requiring males to be present on breeding territories when females are present. In autumn-protogynous species, males may ”play chicken,” balancing the benefits of remaining longer than females and protecting territories for subsequent years against the costs of remaining in the north under deteriorating conditions and delaying the acquisition of a good winter territory.Protogynie et migration automnale: Est-ce que les mâles ”jouent les dégonflés”?


2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Alexander Agboola-Dobson ◽  
Guowu Wei ◽  
Lei Ren

Recent advancements in powered lower limb prostheses have appeased several difficulties faced by lower limb amputees by using a series-elastic actuator (SEA) to provide powered sagittal plane flexion. Unfortunately, these devices are currently unable to provide both powered sagittal plane flexion and two degrees of freedom (2-DOF) at the ankle, removing the ankle’s capacity to invert/evert, thus severely limiting terrain adaption capabilities and user comfort. The developed 2-DOF ankle system in this paper allows both powered flexion in the sagittal plane and passive rotation in the frontal plane; an SEA emulates the biomechanics of the gastrocnemius and Achilles tendon for flexion while a novel universal-joint system provides the 2-DOF. Several studies were undertaken to thoroughly characterize the capabilities of the device. Under both level- and sloped-ground conditions, ankle torque and kinematic data were obtained by using force-plates and a motion capture system. The device was found to be fully capable of providing powered sagittal plane motion and torque very close to that of a biological ankle while simultaneously being able to adapt to sloped terrain by undergoing frontal plane motion, thus providing 2-DOF at the ankle. These findings demonstrate that the device presented in this paper poses radical improvements to powered prosthetic ankle-foot device (PAFD) design.


2000 ◽  
Vol 31 ◽  
pp. 300-306 ◽  
Author(s):  
Daniel S. Vonder Mühll ◽  
Christian Hauck ◽  
Frank Lehmann

AbstractAt two permafrost sites in the Swiss Alps a range of geophysical methods were applied to model the structure of the subsurface. At both sites, borehole information was used to verify the quality of the model results. On the Murtèl-Corvatsch rock glacier (2700 m a.s.L; upper Engadine) a 58 m deep core drilling was performed in 1987. D. c resistivity measurements, refraction seismics, ground-penetrating radar (GPR) and gravimetric surveys allowed the shape of the permafrost table beneath the marked surface microtopography to be determined and the lateral extent of a deeper shear horizon to be established The validity of each method was verified by the borehole information (cores, density log and temperature). A coherent model of the rock-glacier structure was developed. At the Schilthorn (2970 m a.s.L; Bernese Oberland), it was not clear whether permafrost is in fact present. Various geophysical surveys (d.c. resistivity tomography, refraction seismics, GPR and EM-31) gave results that were not typical of permafrost environments. A 14 m percussion drilling revealed warm permafrost and a very low ice content. These geotechnical and geothermal data allowed reinterpretation of the geophysical results, improving modelling of ground conditions. The paper demonstrates that in the difficult terrain of Alpine permafrost, boreholes may be critical in calibration and verification of the results of geophysical methods. The most useful combinations of geophysical techniques proved to be (a) seismics with d.c. resistivity, and (b) gravimetry with GPR.


2017 ◽  
Vol 69 ◽  
pp. 116-124 ◽  
Author(s):  
Isaac Madrid Vergara ◽  
Charalampos Saroglou

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