scholarly journals Assessment of Soil Liquefaction Potential Based on SPT Values at Some Ground Profiles in the North Central Coast of Vietnam

2021 ◽  
pp. 2222-2238
Author(s):  
Nguyen Thi Nu ◽  
Nguyen Thanh Duong ◽  
Bui Truong Son
Keyword(s):  
Standard Penetration Test ◽  
Wide Distribution ◽  
Soil Liquefaction ◽  
Traffic Load ◽  
Engineering Practice ◽  
Central Coast ◽  
Liquefaction Potential ◽  
North Central ◽  
The North ◽  
Coast Of Vietnam

     The North Central Coast of Vietnam has a wide distribution of loose sand which is often exposed on the surface. The thickness changes from a few meters to over ten meters. This sand with the loose state can be sensitive to the dynamic loads, such as earthquakes, traffic load, or machine foundations. It can be liquefied under these loadings, which might destroy the ground and buildings. The Standard Penetration Test (SPT) is widely used in engineering practice and its values can be useful for the assessment of soil liquefaction potential. Thus, this article presents some ground profiles in some sites in the North Central Coast of Vietnam and determines the liquefaction potential of sand based on SPT and using three parameters, including the Factor of Safety against Liquefaction (FSLIQ), Liquefaction Potential Index (LPI), and Liquefaction Severity Number (LSN). The research results show that the FSLIQ, LPI, and LSN values depend on the depth of sand samples and the SPT values. In this study, the sand distributed from 2.0 to 18.0m with (N1)60cs value of less than 20 has high liquefaction potential with FSLIQ<1, LPI is often higher than 0.73, and LSN is often higher than 10. The results also show that many soil profiles have high liquefaction potential. These results should be considered for construction activities in this area.

scholarly journals PHYLOGENETIC ANALYSIS AND SPECIES IDENTIFICATION OF 11 GORGONIAN CORALS (OCTOCORALLIA: ALCYONACEA) IN THE NORTH CENTRAL COAST OF VIETNAM BASED ON MSH1MTDNA AND 28S RDNA MARKERS

2021 ◽  
Vol 9 (08) ◽  
pp. 505-514
Author(s):  
Nguyen Chi Mai ◽  
◽  
NinhThi Ngoc ◽  
Nguyen Xuan Cuong ◽  
Nguyen Hoai Nam ◽  
...  
Keyword(s):  
Species Identification ◽  
Phylogenetic Analyses ◽  
28S Rdna ◽  
Central Coast ◽  
North Central ◽  
The North ◽  
Traditional Classification ◽  
Gorgonian Corals ◽  
Coast Of Vietnam

Vietnam contains diverse marine ecosystems with the high biodiversity of marine organisms, including gorgonian corals of Alcyonacea order. In order to support traditional classification of these corals, in this study mitochondrial barcoding markers msh1 and nuclear 28S rDNA were developed for analysis of 11 specimens collected in 2015 and 2016 from different islands and bays along the North Central coast of Vietnam. Phylogenetic analyses based on msh1 and 28S sequence polymorphism showed that all specimens belonged to Anthozoa class, Octocorallia sub-class and Alcyonacea order. At lower taxa levels, they were divided into 4 sub-orders, 7 families and 7 genera according to 7 distinct clades with bootstrap values from 99-100%.The identifications of 7 out of 11 specimens including Sinularia brassica (2 specimens)and Sinularialeptoclados, Dichotellagemmacea, Annella reticulata, S. conferta and S. nanolobata were in concordance between morphological and molecular methods. The other 4 specimens were only identified at genus levels of Astrogorgia sp., Melithaea sp. Scleronephthya sp. and Muricella sp. by either msh1-morphology or msh1-28S markers. These results highlight the importance of molecular markers to elucidate patterns of biodiversity and species identification of soft coral.

scholarly journals Hydrodynamic Condition Modeling along the North-Central Coast of Vietnam

2020 ◽  
Vol 10 (3) ◽  
pp. 5648-5654
Author(s):  
D. D. Cham ◽  
N. T. Son ◽  
N. Q. Minh ◽  
N. T. Hung ◽  
N. Tien Thanh
Keyword(s):  
Sediment Transport ◽  
River Flow ◽  
Morphological Changes ◽  
Main Channel ◽  
Low Flow ◽  
Hydrodynamic Condition ◽  
Central Coast ◽  
North Central ◽  
The North ◽  
Coast Of Vietnam

An extremely dynamic morphology of the estuary is observed in the coastal regions of Vietnam under the governing processes of tides, waves, and river system flows. The primary target of this paper is to provide insight into the governing processes and morphological behavior of the NhatLe estuary, located in the north-central coast of Vietnam. Based on measured data from field surveys and satellite images combined with numerical model simulations of MIKE and Delft3D, the influences of seasonal river flow, tides, and wave dynamics on the sediment transport and morphological changes are fully examined. The study showed that freshwater flow in the flood season plays a central role in cutting off the southern sandspit, maintain and shaping the main channel. The prevailing waves in winter and summer induce longshore drift and sediment transport in the southeast to northwest direction. In the low flow season, this longshore sediment transport is dominant, causing sediment to deposit on the southern side of the ebb tidal delta and elongating the southern sandspit which narrows the estuary entrance and reorients the main channel.

scholarly journals Risk management and logistical performance: A case of the fishery supply chain north central coast of Vietnam

2021 ◽  
Vol 9 (3) ◽  
pp. 739-744 ◽  
Author(s):  
Tho Nguyen Gia ◽  
My Mai Bac ◽  
Vien Le Van
Keyword(s):  
Supply Chain ◽  
Central Coast ◽  
North Central ◽  
Operational Risks ◽  
The North ◽  
Market Risks ◽  
Study Results ◽  
Supply Risks ◽  
Coast Of Vietnam ◽  
The Impact

In any given supply chain, risks can occur, and it can reduce the performance of an entire production line. To maintain a competitive advantage, manufacturers should anticipate and manage risks. This paper aims to assess the impact of risks associated with the fishery supply chain on logistics performance. The research was conducted with 297 seafood producers on the North Central Coast of Vietnam. The study results show that risk factors such as supply risks, market risks, operational risks, environmental risks, and financial risks have a direct impact on the logistical performance of firms in the fishery supply chain. The study also proposes solutions to limit risks for businesses.

scholarly journals The effect of forestland allocation to the livelihoods of local people in the North Central Coast of Vietnam: A case in Nam Dong district

Tropics ◽  
2016 ◽  
Vol 24 (4) ◽  
pp. 169-180 ◽  
Author(s):  
Thi Thuy Phuong Nguyen ◽  
Misa Masuda ◽  
Seiji Iwanaga
Keyword(s):  
Local People ◽  
Central Coast ◽  
North Central ◽  
The North ◽  
Coast Of Vietnam

scholarly journals A Range Extension for the Rock Vole, Microtus chrotorrhinus, in Labrador

2005 ◽  
Vol 119 (3) ◽  
pp. 412 ◽  
Author(s):  
Sarah W. Lansing
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Range Extension ◽  
Southern Coast ◽  
Central Coast ◽  
North Central ◽  
The North ◽  
Southern Island

Rock Voles (Microtus chrotorrhinus) were previously documented only from the southern coast of Labrador and the Strait of Belle Isle south of Hamilton Inlet. During two field seasons in 2000 and 2001, both in July, six Rock Vole specimens were collected on Southern Island, off the north-central coast of Labrador, extending the range of the subspecies Microtus chrotorrhinus ravus approximately 250 km to the central Labrador coast north of Hamilton Inlet. Rock Voles were trapped primarily in stunted Black Spruce (Picea mariana) forest and areas associated with rocks, thick brush, and water.

scholarly journals Validation and Verification of Semi-Empirical Methods for Evaluating Liquefaction Using Finite Element Method

2018 ◽  
Vol 149 ◽  
pp. 02028 ◽  
Author(s):  
Soukaina Touijrate ◽  
Khadija Baba ◽  
Mohamed Ahatri ◽  
Lahcen Bahi
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Water Pressure ◽  
Soil Liquefaction ◽  
Empirical Methods ◽  
Liquefaction Potential ◽  
North West ◽  
Cone Penetration Tests ◽  
The North ◽  
Semi Empirical

Liquefaction is a hazardous and temporary phenomenon by which a soil saturated with water loses some or all of its resistance. The undrained conditions and a cyclic load increase the pores water pressure inside the soil and therefore a reduction of the effective stress. Nowadays many semi-empirical methods are used to introduce a proposition to evaluate the liquefaction's potential using the in-situ test results. The objective of this paper is to study their ability to correctly predict the liquefaction potential by modelling our case using finite element methods. The study is based on the data of Cone Penetration Tests experimental results of the Casablanca-Tangier High-Speed Line exactly between PK 116 + 450 and PK 116 + 950 and near of Moulay-Bousselham city. It belongs to the Drader-Soueir basin region which is located in the North-West of Morocco. This region had a specific soil’s formation, the first 50 meters are characterised by the existence of sand layers alternating with layers of clay. These formations are very loose and saturated which suggests the possibility of soil liquefaction. We present and discuss the results of applying the Olsen method [1], the Juang method [2] and the Robertson method [3], in the evaluation of liquefaction susceptibility. Apart from the previous empirical analysis to evaluate the liquefaction potential, numerical modelling is performed in this study.

Regression model for evaluating liquefaction potential by discriminant analysis of the SPT N value

2005 ◽  
Vol 42 (3) ◽  
pp. 856-875 ◽  
Author(s):  
Sheng-Yao Lai ◽  
Ping-Sien Lin ◽  
Ming-Jyh Hsieh ◽  
Hoi-Fung Jim
Keyword(s):  
Discriminant Analysis ◽  
Standard Penetration Test ◽  
Cyclic Stress ◽  
Soil Liquefaction ◽  
Liquefaction Resistance ◽  
Multivariate Statistical ◽  
Liquefaction Potential ◽  
Cyclic Stress Ratio ◽  
N Value ◽  
Spt N Value

Discriminant models are developed for evaluating soil liquefaction potential, using standard penetration test (SPT) data for 592 occurrences of liquefaction and nonliquefaction. The discriminant model used is a multivariate statistical method. The square root of the SPT N value, (N1)601/2, and the logarithm of the cyclic stress ratio, ln CSR7.5, are adopted as the major parameters for analyses. Two models measuring liquefaction resistance through the SPT N value are also established in this study, which allows calculated results to be compared with the empirical curves. Key words: liquefaction, discriminant analysis, misclassified probability.

scholarly journals Agricultural production responding to climate change in the north central coast of vietnamidentified bythe amount of rainfall and potential evapotranspiration (PET)

2018 ◽  
Vol 2 (6) ◽  
pp. 5-10
Author(s):  
Nguyen Thi Hoang Anh ◽  
Mai Kim Lien
Keyword(s):  
Climate Change ◽  
Plant Growth ◽  
Agricultural Production ◽  
Weather Forecasting ◽  
Potential Evapotranspiration ◽  
Modern Technology ◽  
Central Coast ◽  
Monthly Basis ◽  
North Central ◽  
The North

Climate change is driving dangerous and more unpredictable weather. It has broken historical records of hydro-meteorological observations, consequently leading challenges in operational forecasting. In order to improve crop yield and reduce impacts of climate change on agricultural production, it is necessary to obtain sources of weather information. The estimations of rainfall and PET can enable us to identify plant growth and water supply capacity for any plant in the mountainous areas at Quy Hop District, Nghe An (one part of the North Central Coast) on a monthly basis. The updated information on weather forecasting technology and the application of modern technology responding to climate change in Quy Hop provided results related to cumulative rainfall chart. It can forecast accurately the plant growth and the best time for watering plants and plays an important role in the agricultural production.  

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