scholarly journals DETERMINATION OF THE COLLAPSE POTENTIAL OF SABKHA SOIL AND DUNE SAND ARID SURFACE SOIL DEPOSITS IN KUWAIT

2021 ◽  
Vol 83 (3) ◽  
pp. 93-100
Author(s):  
Fahad A. Al-otaibi ◽  
Humoud Melfi Aldaihani

Ensuring the sustainability of critical and limited natural soil resources is a major challenge in arid regions such as Kuwait. Investigations should be performed to identify and characterise collapsible surface soil deposits, and collapse potential should be assessed if possible in order to evaluate suitable stabilizing techniques. The cementation effect of different types of salts gives arid soils their considerable strength and stiffness in dry conditions. The collapse in these soils may occur due to the reduction of the chemical or physical bonds between the soil particles under wet conditions. Collapse Potential (CP) is an indication of the collapsibility of these soils. This paper presents the results of experimental work that was carried out to evaluate the collapse potential of two types of surface soil: sabkha soil and dune sand. The experimental program included physical and chemical soil characterization alongside a modified compaction test. The collapsibility of the soil at a stress of 200 kPa was obtained by performing a Single Collapse Test (SCT) via a conventional odometer device in a temperature- and humidity-controlled environment. Collapse potential index tests were performed on the tested soil samples collected from eight locations in two study areas. The results suggest the problem severity is slight to none. However, the CP was higher for the sabkha soil samples than for the dune sand samples. The increase in collapsibility of the sabkha soil samples may be attributed to the removal of bonding between cementing particles upon wetting.

2009 ◽  
Vol 46 (4) ◽  
pp. 247-249
Author(s):  
M. Lišková

AbstractA rare nematode species Leptonchus granulosus Cobb, 1920 was recovered from soil samples collected from pine forest from the locality of Mužla, in south-western part of the country and from fruit (apricot and peach) orchards from the locality of Svätá Mária, in south-eastern region of Slovakia. In spite of geographical distance of the localities, both are characterised by warm and dry conditions and by specific very light sandy soils derived from dune sand. Only females were recovered from both localities.


Author(s):  
Byambasuren Ts ◽  
Khuukhenkhuu B ◽  
Ochirbat G ◽  
Vasilyeva I E ◽  
Shabanova E V ◽  
...  

In this paper were presented the background values in total content and bioavailable concentration of trace elements in regional surface soil of Ulaanbaatar city. The main goal of this study is to establish the total content and bio-available concentration of microelements in natural soil of around Ulaanbaatar and to standardize them as main criterion in assessment of soil pollution by heavy metals. Background sites were selected in 20-40 km from the city center and in the resident zone. In soil samples using the complex analytical methods of atomic spectroscopy have been determined the total content and bio-available concentration of microelements.


Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1131
Author(s):  
Soonkie Nam ◽  
Marte Gutierrez ◽  
Panayiotis Diplas ◽  
John Petrie

This paper critically compares the use of laboratory tests against in situ tests combined with numerical seepage modeling to determine the hydraulic conductivity of natural soil deposits. Laboratory determination of hydraulic conductivity used the constant head permeability and oedometer tests on undisturbed Shelby tube and block soil samples. The auger hole method and Guelph permeameter tests were performed in the field. Groundwater table elevations in natural soil deposits with different hydraulic conductivity values were predicted using finite element seepage modeling and compared with field measurements to assess the various test results. Hydraulic conductivity values obtained by the auger hole method provide predictions that best match the groundwater table’s observed location at the field site. This observation indicates that hydraulic conductivity determined by the in situ test represents the actual conditions in the field better than that determined in a laboratory setting. The differences between the laboratory and in situ hydraulic conductivity values can be attributed to factors such as sample disturbance, soil anisotropy, fissures and cracks, and soil structure in addition to the conceptual and procedural differences in testing methods and effects of sample size.


2019 ◽  
Vol 106 ◽  
pp. 01016
Author(s):  
Jakub Zięba

The article presents the mechanical behaviour of calcareous waste under consolidated and drained condition in Triaxial compression test (CD). The host material currently being considered for the construction purpose of several buildings in Poland. One of the location of calcareous waste is in Łagiewniki area (in Cracow) [1,2]. In this work, particular attention has been paid to the to ensure fully saturation for all the tested soil samples and avoid generation of unwanted excess pore water pressure during shearing stage. The saturation level of soil samples was estimated based on Skempton’s law (B>0.95). CD Triaxial test have been conducted in order to derive information on its strength and stiffness properties.


1987 ◽  
Vol 28 (3) ◽  
pp. 393-406 ◽  
Author(s):  
Patricia L. Fall

AbstractSurface soil samples from the forested Chuska Mountains to the arid steppe of the Chinle Valley, Northeastern Arizona, show close correlation between modern pollen rain and vegetation. In contrast, modern alluvium is dominated by Pinus pollen throughout the canyon; it reflects neither the surrounding floodplain nor plateau vegetation. Pollen in surface soils is deposited by wind; pollen grains in alluvium are deposited by a stream as sedimentary particles. Clay-size particles correlate significantly with Pinus, Quercus, and Populus pollen. These pollen types settle, as clay does, in slack water. Chenopodiaceae-Amaranthus, Artemisia, other Tubuliflorae, and indeterminate pollen types correlate with sand-size particles, and are deposited by more turbulent water. Fluctuating pollen frequencies in alluvial deposits are related to sedimentology and do not reflect the local or regional vegetation where the sediments were deposited. Alluvial pollen is unreliable for reconstruction of paleoenvironments.


2005 ◽  
Vol 42 (2) ◽  
pp. 491-498
Author(s):  
Dae-Sang Kim ◽  
Kazuo Konagai

Earthquake observations at different sites within alluvial soil deposits have demonstrated that the motion of buried underground structures closely follows that of the surrounding soil. Therefore, it is usual in a seismic design process to apply free-field ground displacements through Winkler-type soil springs to an underground structure to evaluate stress patterns induced within its structural members. Using a simplified approach, this paper provides a clear understanding of resonant horizontal ground displacement of and strain in a surface soil deposit with a radical change of depth and of where they occur.Key words: simple approach, seismic design, earthquake, resonance, underground structures.


2007 ◽  
Vol 87 (1) ◽  
pp. 73-83 ◽  
Author(s):  
D. Kimaragamage ◽  
O O Akinremi ◽  
D. Flaten ◽  
J. Heard

Quantitative relationships between soil test phosphorus (STP) methods are needed to guide P management especially in manured soils with high P. Our objectives were: (i) to compare amounts of P extracted by different methods; (ii) to develop and verify regression equations to convert results among methods; and (iii) to establish environmental P thresholds for different methods, in manured and non-manured soils of Manitoba. We analyzed 214 surface soil samples (0–15 cm), of which 51 had previous manure application. Agronomic STP methods were Olsen (O-P), Mehlich-3 (M3-P), Kelowna-1 (original; K1-P), Kelowna-2 (modified; K2-P), Kelowna-3 (modified; K3-P), Bray-1 (B1-P) and Miller and Axley (MA-P), while environmental STP methods were water extractable (W-P), Ca Cl2 extractable (Ca-P) and iron oxide impregnated filter paper (FeO-P) methods. The different methods extracted different amounts of P, but were linearly correlated. For an O-P range of 0–30 mg kg-1, relationships between O-P and other STP were similar for manured and nonmanured soils, but the relationships diverged at higher O-P levels, indicating that one STP cannot be reliably converted to another using a single equation for manured and non-manured soils at environmentally critical P levels (0–100 mg kg-1 O-P). Suggested environmental soil P threshold ranges, in mg P kg-1, were 88–118 for O-P, 138–184 for K1-P, 108–143 for K2-P, 103–137 for K3-P, 96–128 for B1-P, 84–111 for MA-P, 15–20 for W-P, 5–8 for Ca-P and 85–111 for FeO-P. Key words: Phosphorus, soil test phosphorus, manured soils, non-manured soils, environmental threshold


2021 ◽  
Vol 851 (1) ◽  
pp. 012026
Author(s):  
A T Sekarningsih ◽  
W Budianta ◽  
I W Warmada ◽  
H Hinode

Abstract The effect of urbanization and industrialization in the urban city is soil contamination by heavy metals. This study was conducted to assess Pb, Cu, Zn, and Cd, in the soil of Yogyakarta city and its surrounding, Indonesia. The assessment was done by analyzing 45 surface soil samples in the study area, divided into three-zone. They are divided based on the distance of each zone to the center of the city. The zone III is located in the outermost of the study area, and zone I is inside the city. The results of the study showed that generally, the highest concentration of metals was located in zone I, which is located near or directly situated in a city center. The result indicated that Pb and Cd had the highest pollution index compared to Cu and Zn. The pollition load indeks (PLI) and geoaccumulation indeks (Igeo) calculations in the whole study area showed that the values demonstrated a moderate class in average. Special attention was needed to be given to the zone I, which has a higher PLI and Igeo index to reduce the source of emission for Pb and Cd.


2021 ◽  
Vol 2 (5) ◽  
pp. 24-28
Author(s):  
Nnamdi Michael Ahiamadu ◽  
Ify L. Nwaogazie ◽  
Yusuf O. L. Momoh

The study assessed the concentration of heavy metals in three oil spill sites in Emohua local government area in Rivers State, Nigeria. Soil samples were collected at depth 0-30cm for surface soil samples and up to 10m for sub-surface soil samples depending on the depth of borehole. Groundwater samples were collected from drilled boreholes while the surface water samples were collected from fishponds or water bodies (rivers) close to the oil spill sites. The samples taken from the oil spill sites were analysed to determine the level of concentration of 10 Department of Petroleum Resource (DPR) specified heavy metals (Cd, Zn, Cu, Pb, Cr, Ba, Ni, Hg, As, and Co). BUCK Scientific Atomic Absorption Spectrophotometer (AAS) was used in detecting the concentration of the heavy metals. For the surface soil, Pb concentration in site A and B were significantly higher than what was obtained at site C, with a mean concentration of 219.70, 130.01 and 3.41mg/kg respectively for the three sites. The mean lead (Pb) concentration obtained in the surface soil was within DPR and United State Environmental Protection Agency (USEPA) acceptable limits. Barium also has significant concentration in both the surface soil and sub-surface soil. Kruskal Wallis test indicated significant difference in the Pb, Cd, Zn, Cu, Cr and Ba concentration in surface/topsoil among the three sites and also indicated significant difference in the concentrations of Pb, Cd, Cr, Ni, Ba and As in sub-surface soil among the sites. Little heavy metal concentration was found in both the groundwater and surface water. The study showed that even if some heavy metals were detected at the oil spill sites, they do not pose any serious health risk, as all the heavy metals in the four environmental media at the three sampling sites were below the national limit stipulated by the Department of Petroleum Resource (DPR), Nigeria.


2014 ◽  
Vol 979 ◽  
pp. 35-38
Author(s):  
Prasong Kessaratikoon ◽  
Ruthairat Boonkrongcheep ◽  
Supphawut Benjakul ◽  
Suchin Udomsomporn

The specific activity of the natural (40K, 226Ra and 232Th) and anthropogenic (137Cs) radionuclides have been studied and evaluated for 97 surface soil samples collected from 7 districts of Phang Nga province in the south of Thailand. High-purity germanium (HPGe) detector and gamma ray spectrometry analysis system were employed to measure and analyze the experimental results. It was found that, the ranges of specific activities of 40K, 226Ra, 232Th and 137Cs in surface soil samples are 251.50 – 15740.34, 15.21 – 791.42, 18.14 – 854.34 and < 0.33 – 16.91 Bq/kg with average values are 2886.77 ± 225.93, 165.71 ± 8.45, 160.36 ± 7.93 and 5.76 ± 2.49 Bq/kg, respectively. The results were also compared with some research data in national and global radioactivity measurement and evaluations. Furthermore, the radiological hazards of Phang Nga province were calculated through the radium equivalent activity (Raeq), the external hazard index (Hex), the gamma absorbed dose rate (D) and the annual effective dose rate (AEDout) and also compared with research data in the south of Thailand and the safety limits recommended values by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Moreover, the radioactive contour maps of the natural (40K, 226Ra and 232Th) and anthropogenic (137Cs) radionuclides have been also created for the investigated area.


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