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Landslides and slope stability under seismic action
Published in John G.Z.Q. Wang, K. Tim Law, Siting in earthquake zones, 2022
For investigation of the sloped or hilly areas in earthquake zones, emphasis should be put on the evidences or traces of historical events, if any, such as surface faulting, ruptures, waving deformation of ground surface and sand boils/sand seams, etc. A particular conclusion should be drawn as to whether any of these traces caused any past sliding of the sloped ground. Field work such as borehole drilling and sampling, digging trenches and pits, sounding and penetration tests, geophysical surveys and ground water monitoring are useful towards this end. In addition, stratigraphic characteristics such as fractured zones, fissures and joints, especially the weak and soft sandwich layer in rock formations should be investigated in details. If necessary use downhole camera or television for the investigation.
General Types of Contaminated Site Restoration Methods and Technologies
Published in Kofi Asante-Duah, Management of Contaminated Site Problems, 2019
Excavation is the physical process of removing soil by digging and scooping it out for treatment and/or disposal. It is often an initial step in many of the site restoration technology options available for the treatment of contaminated soils. Soil excavation, transport, and disposal processes generally use mechanized equipment to move contaminated soil. During excavation actions, adequate precautions and measures are usually needed to minimize VOC emissions and fugitive dust generation.
Bioremediation
Published in Edgardo R. Donati, Heavy Metals in the Environment, 2018
Conventional methods for the remediation of Cd-contaminated soil have been classified into two major types. In-situ bioremediation doesn’t need the removal of soil from the contaminated sites. Once the contaminated part is identified, various treatment procedures are followed to remove Cd from the soil. Lime and acid treatment is an easy procedure to change the pH of the soil to alter the mobility of various Cd species present within. The treatment of soil with Cd-chelating agents is also useful in decreasing Cd content of the contaminated soil. The change in soil pH sometimes destroys its natural properties and removes soil microbiota to a significant extent. Chelation techniques non-specifically remove essential metals to result in soil infertility. In ex-situ bioremediation, the areas with greatest Cd contents are identified and removed. The soil is further processed for Cd removal. Digging up the contaminated site generates dust particles and increases the risk of exposure. Also, this method is cost prohibited for large areas and suffers from the drawback of large scale burial of waste materials.
Ex situ studies on Macrotermes bellicosus as a potential bioremediation tool of polluted dump soil sites for Sub Saharan Africa
Published in Soil and Sediment Contamination: An International Journal, 2022
Daniel Ingo Hefft, Osikemekha Anthony Anani, Felix Aigbodion, Charity Osadagbonyi, Charles Oluwaseun Adetunji, Afure Ejomah, Uyi Osariyekemwen, Alex Enuneku
Southern Africa is a well-known region where termites can be responsible for 3–100 % of crop losses (Mitchell 2002). However, it cannot be ignored that termites are a key contributor to soil quality and that they limit erosion. Termites act as bio-turbators by creating increasing water infiltration through digging and construction activities (Jouquet et al. 2016, 2021). Further, fungus-growing termites have been reported to take pH0 lowering influence on surface charge properties as well as creating soils with an improved actual capacity to hold nutrient basic cations (Mujinya et al. 2010). A recent study by Chisanga, Mbega, and Ndakidemi (2020) and by Nwosu and Akor (2018) has recognized these potentials of termites to improve soil quality and health as a tool to engineer soils in Southern Africa and Sub-Saharan.
Underground pipelines and railway infrastructure – failure consequences and restrictions
Published in Structure and Infrastructure Engineering, 2020
A. H. S. Garmabaki, Stefan Marklund, Adithya Thaduri, Annelie Hedström, Uday Kumar
Furthermore, the relation between the age and the leakage rate of pipes is not straightforward and there may be several covariates that might affect the leakage rate for instance, previous leaks, pipe loads, construction work, construction periods, the pipe length and material, and the geographical location (Malm et al., 2011; Røstum, 2000; Standard-BVS-585.20, 2005-09-19). For instance, it has been shown that grey-iron pipes installed during the 1950s and 1960s have an increased leakage rate. This is most likely due to the transition from digging by hand to digging using excavators, as the pipes were dropped into larger pipes with poor support from the surrounding soil. Similarly, road salting increases the risk of external corrosion. Due to the need to develop urban areas during the 1960s, a construction rush took place in which the installed pipes were of poorer quality. Pipelines are installed in various geographical locations, and certain soils in these locations can increase the external corrosion of the pipeline. The soils that are especially corrosive are clay soils with a high sulphur content. In a British study, it was found that pipes in clay soils exhibited almost twice as much leakage as pipes in sandy soils (Malm et al., 2011). Moreover, loose soil can cause sedimentation, as well as changing the pressure conditions, resulting in pressure drops which can lead to leaks in nearby pipes. According to Sundahl (1996), leaks tend to come in groups and to be close to each other physically and temporally.
Applying the combination of U-statistic and Mahalanobis distance as a multivariate structural method for the delineation of geochemical anomalies
Published in Geosystem Engineering, 2018
Seyyed Saeed Ghannadpour, Ardeshir Hezarkhani
A rock sampling grid with square cells having a side of 100 m has been executed in the Parkam exploration district. There were 377 samples collected and analyzed for major and trace element concentration by ICP-OES and ICP-MS at Amdel Mineral Laboratories, Adelaide, South Australia. Figure 4 shows the location of these samples as well as the lithology from which they were collected. The samples located in sediments (Figure 4) were collected either from rock outcrops or from trenches having access to rock, and mostly shared the lithology of their adjacent igneous units. Locations with no sample in the grid (Figure 4) had no access to rock at these locations due either to the absence of outcrops or the relatively great thickness of the sediments or soil that obstructed manual digging.