Slide Plane Research Articles

On the Process of Formation of the Slide Planes at Kuchinotsu Landslide Area (III)

On the Process of Formation of the Slide Planes at Kuchinotsu Landslide Area (III)

On the Process of Formation of the Slide Planes at Kuchinotsu Landslide Area (II)

On the Process of Formation of the Slide Planes at Kuchinotsu Landslide Area (II)

The Sgurr Beag Slide–a major tectonic break within the Moinian of the Western Highlands of Scotland

Detailed mapping of an area at the head of Loch Hourn, Inverness-shire, has shown that major facies changes occur within the Glenelg–Knoydart succession (Ramsay & Spring 1962) as it is traced north-eastwards from the type area. A slide, here recognized as a tectonic break of major importance within the Moine Nappe, separates members of this succession at Kinloch Hourn from rocks of a different stratigraphical sequence farther east. Lewisian-type rocks rest upon the slide plane and together with an overlying sequence of Moinian rocks have been slid against upper members of the Glenelg–Knoydart succession. It is suggested that the Scardroy Lewisian, which forms a sheet-like body in central Ross-shire, has been brought to its present position by this slide movement and not thrust wedge-like into an unbroken Moinian succession as suggested by Sutton & Watson (1962). Three phases of folding are recognized and the geometry of the major folds and their structural relationship to the slide plane is described in detail. Slide movement occurred during the second folding and before the peak of the regional metamorphism.

Landslide appeared at Kurihara, Onomichi City, Hiroshima Prefecture

On the basis of data obtained concerning the terrain under consideration has it become clear that a singular variation in mechanical property, liable to appear in the younger geology composed of the Tertiary to Quaternary formation, might have caused a sort of landslide.On the other hand, a trial for determining the slide plane as well as stability of the slope in section has been disperted in relaton to some disperted in relaton to some analytical method.

Saltsonden och dess användning vid bestämning av skredbottnen vid Göta

Abstract The Electrical Sounding Tool and Its Applications in the Determination of the Slip Surface at Göta, Western Sweden A new method of locating slip surfaces of landslides by means of electrical resistance sounding is described. The method is based on the fact that, for an undisturbed clay, the variation of salinity with depth (indicated approximately by the resistance curve) is slight and gradual. Very different salt distributions to this are found, however, in the Göta River Valley, Sweden, where numerous large landslides have occurred. Here the salinity of the clay is normally greatest in the vicinity of the river and diminishes as the distance from the river increases. When a slide occurs, however, the upper clay layers move riverwards, so that clay of lower salinity comes to rest above clay of higher salinity. The resistance curve will thus show, at the junction of the two clays of unlike salinity, a sharp step representing the slip surface. This conclusion is checked by the extraction of clay cores, which show that in this case the zone of sliding can be subdivided into three parts. Underneath is a black sulphide-clay which at the slide plane proper changes sharply to light gray clay above which is a smooth transition to black sulphide-clay again. A preliminary description of the application of the method to the great slide at Göta is also given.

Landslides-Ventura Avenue Oil Field: ABSTRACT

The soft Pliocene formations in the Ventura district are particularly susceptible to landsliding. Resultant movement has presented difficult and expensive problems in connection with the development of oil-producing properties. Extensive work has been undertaken by the Tide Water Associated Oil Company in an effort to stop existing slides and to prevent the development of new slides in the Ventura Avenue oil field. The landslides in this field are of two types, bedding-plane slides and circular-type slides. Bedding-plane slides move along parallel bedding planes in areas where the dip of the formation exceeds 15° and is in the same direction as the surface slope. Circular-type slides are independent of the stratification of the formation. They occur in stratified material which is not dipping in the same direction as the surface slope, and in unstratified material such as old slides where the bedding has been destroyed. The two principal causes of landsliding are the presence of water in the formation and the disturbance of equilibrium. Water is probably the most important cause for it lowers the coefficient of friction within the slide itself and along existing slide planes, reduces the shear and tensile strength of the formation, increases the weight of the landslide mass, and creates a lifting force due to hydrostatic pressure in the lower part of the slide. The state of equilibrium may be disturbed by a redistribution of weight by either natural or artificial means. Three basic methods of landslide control are practiced in the Ventura Avenue field. They are the removal of water from the slide, the elimination of the source of the water, and the redistribution of the load. Water is removed by nearly horizontal Hydrauger holes, vertical water-well shafts, drain tiles, and tunnels. Elimination of the source of the water is accomplished by dressing and oiling the surface to facilitate rainwater run-off, and by preventing waste water, drilling mud, et cetera, from seeping into the formation. Redistribution of the load consists in removing earth from the head of the slide and compacting this material at the toe. It is perhaps too early to judge the full effect of the corrective measures employed. However, results of observation in the past 3 years indicate that the measures taken have been highly successful. End_of_Article - Last_Page 134------------

An Experimental Apparatus for the Projection of Motion Pictures in Relief<!--<xref ref-type="other" rid="fn1-10.5594_J02037">*</xref>-->

An experimental demonstration apparatus is described for projecting motion pictures in relief by application of the principle of the parallax panoramagram. A series of thirty-two posed, still pictures is made by the use of a large diameter concave mirror forming an image on a transparent concave ridged screen, which in turn is imaged on lantern-slide plates. Positives from these negatives are mounted on a slowly rotating disk in the slide plane of a projection lantern. A flashing mercury lamp illuminates each picture as it comes into position. The projected image is received upon the back of a translucent convex ridged screen. When viewed from the front, the moving picture changes its appearance with the observing position, and exhibits stereoscopic relief.