| 1. |
- Sadiq, Sakar, et al.
(author)
-
Mechanism of Haibat Sultan Mountain Landslide in Koya, North Iraq
- 2016
-
In: Engineering. - : Scientific Research Publishing, Inc.. - 1947-3931 .- 1947-394X. ; 8:8, s. 535-544
-
Journal article (peer-reviewed)abstract
- Haibat Sultan Mountain is a long range with elevation of about 860 m (a.s.l.); the PilaSpi Formation forms its carapace in Koya vicinity, with relief difference of about 300 m from Koisanjaq plain. The PilaSpi Formation consists of well thickly to massively bedded dolostone and dolomitic limestone with thickness of about 120 m in Koya vicinity. The main trend is NW - SE being a limb of Bustana anticline representing part of the southwestern limb, with dip amount that ranges from (15 - 30). On 11th of November 2015 a landslide had occurred after a heavy rainfall along Koya - Dukan main road. The type of the slide was plane sliding due to daylight slope, which was formed afterthe road cut. The length of the slide area: along the road is 90 m with height of 40 m forming almost a parallelogram shape; the thickness of the slid beds is about 2.5 m. The estimated volume of the slid mass is 9000 m3. The main cause of the landslide is the presence of daylight slope, high slope angle; more than the dip angle, presence of old crack surfaces which are filled by reddish brown clayey residual soil. After the he heavy rain fall, which lasted for 20 hours, the infiltrated rain water in the bedding planes in the well bedded, cracked, and jointed beds has increased the pore pressure and decreased the internal friction angle; therefore, the sliding has occurred. The root of the slid mass is below the base of the paved road; therefore, that part which is above the paved road has slid. The remaining part is highly cracked and partly accumulated in the base of the slid mass. Fortunately, the height of the slid mass is only 40 m and the relief difference between the crown area and the toe area is about 50 m; otherwise the slid mass would be larger than the present slid mass. From the field inspection, it is very clear that the involved area is very unstable and in critical equilibrium. The presence of daylight bedding above the crown area, clayey soil in the fractures and open joints and steep slope all are very favorable conditions for triggering the unstable slope, consequently developing of another landslide with larger mass.
|
|
| 2. |
- Sissakian, Varoujan, et al.
(author)
-
Landslides in Hareer Anticline, Central Northern Part of Iraq
- 2017
-
In: Journal of Earth Sciences and Geotechnical Engineering. - : Scientific Press International Limited. - 1792-9040 .- 1792-9660. ; 7:2, s. 25-43
-
Journal article (peer-reviewed)abstract
- 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.
|
|
