scholarly journals Implications of physical and chemical changes in volcanic ash soils related to road construction

2021 ◽  
Vol 2118 (1) ◽  
pp. 012012
Author(s):  
L R Vásquez-Varela ◽  
C Mendoza

Abstract Soils derived from weathered pyroclastic material in a humid tropical environment, known as volcanic ash soils, cover a low portion of the Earth’s surface. However, its unique characteristics, such as high porosity, low unit weight, high water content, and susceptibility to change in properties by drying and remolding, justify its study due to the impact of these characteristics in the construction of embankments and road subgrades, particularly on the compaction characteristics. The urban settlements located in the tropical zone, close to areas of volcanic activity, develop their road infrastructure on this type of soil. Under laboratory conditions, these soils’ chemical and physical changes, particularly on the particle arrangement or fabric, create a gap between their expected and actual behavior at the construction site. This article presents some problems in road construction related to these unique features and how to deal with them on the construction site, applying conventional classification and compaction tests in the lab and construction site. The particularities of the soils in these conditions are explained using unconventional tests to assess the microscopic effects of compaction on the soil fabric.

2021 ◽  
Vol 940 (1) ◽  
pp. 012091
Author(s):  
A Setiawan

Abstract This article analyzes the impact of the construction of the Cinere-Jagorawi (Cijago) Toll Road Section II, which connects the Bogor Highway and the Kukusan area on the environment around the toll road construction site. Most of the Kukusan areas affected by the toll road construction project are open areas and shrubs, which are habitats for wild animals, especially snakes so that the balance of snake habitat in the area is disturbed. The research method used in this study is the historical method which consists of four stages, namely heuristics, verification, interpretation, and historiography. In addition to books obtained from several libraries, the data used in this study were also obtained from interviews with people living near toll road construction projects, especially ornamental plant traders. This research shows that environmental changes due to the construction of toll road infrastructure impact the disruption of the habitat of several wild animals and an increase in temperature and concerns about the availability of clean water in the future, especially in the Kukusan area.


2013 ◽  
Author(s):  
Angela Schmitt ◽  
Ruzica Vujasinovic ◽  
Christiane Edinger ◽  
Julia Zillies ◽  
Vilmar Mollwitz

2004 ◽  
Vol 68 (1) ◽  
pp. 313 ◽  
Author(s):  
Emmanuel Joussein ◽  
Nathalie Kruyts ◽  
Dominique Righi ◽  
Sabine Petit ◽  
Bruno Delvaux

Author(s):  
M. von der Thannen ◽  
S. Hoerbinger ◽  
C. Muellebner ◽  
H. Biber ◽  
H. P. Rauch

AbstractRecently, applications of soil and water bioengineering constructions using living plants and supplementary materials have become increasingly popular. Besides technical effects, soil and water bioengineering has the advantage of additionally taking into consideration ecological values and the values of landscape aesthetics. When implementing soil and water bioengineering structures, suitable plants must be selected, and the structures must be given a dimension taking into account potential impact loads. A consideration of energy flows and the potential negative impact of construction in terms of energy and greenhouse gas balance has been neglected until now. The current study closes this gap of knowledge by introducing a method for detecting the possible negative effects of installing soil and water bioengineering measures. For this purpose, an environmental life cycle assessment model has been applied. The impact categories global warming potential and cumulative energy demand are used in this paper to describe the type of impacts which a bioengineering construction site causes. Additionally, the water bioengineering measure is contrasted with a conventional civil engineering structure. The results determine that the bioengineering alternative performs slightly better, in terms of energy demand and global warming potential, than the conventional measure. The most relevant factor is shown to be the impact of the running machines at the water bioengineering construction site. Finally, an integral ecological assessment model for applications of soil and water bioengineering structures should point out the potential negative effects caused during installation and, furthermore, integrate the assessment of potential positive effects due to the development of living plants in the use stage of the structures.


2020 ◽  
Vol 63 (1) ◽  
Author(s):  
Won-Pyo Park ◽  
Kong-Man Chang ◽  
Hae-Nam Hyun ◽  
Kyung-Hwan Boo ◽  
Bon-Jun Koo

Abstract It is important to evaluate leaching behavior in agricultural soils to prevent the pollution of groundwater by pesticides. We identified the distribution coefficients (Kd) of ten pesticides with different physicochemical properties and compared their leaching characteristics using wick lysimeters from three distinct soil types on Jeju Island. The Kd values varied by pesticide and soil, but were within the range of 1.2 to 4231 L kg−1. Based on the European standard (Kd < 10 L kg−1), six pesticides (alachlor, ethoprophos, carbofuran, napropamide, tebuconazole, and etridiazole) were mobile in at least one tested soil, and their soil organic carbon affinity was ≤ 5.811. This value differed greatly from the other pesticides (16.533 and higher). The solubility of the six mobile pesticides was ≥ 32 mg L−1, which substantially differed from the other pesticides (≤ 0.71 mg L−1). Thus, we conclude that our mobility assessment, which is based on Kd values, can be used to predict the leaching of pesticides in the volcanic ash soils of Jeju Island. The use of pesticides should be strictly controlled to reduce the possibility of groundwater contamination.


2021 ◽  
Vol 13 (10) ◽  
pp. 5688
Author(s):  
Jangyoul You ◽  
Kipyo You ◽  
Minwoo Park ◽  
Changhee Lee

In this paper, the air flow characteristics and the impact of wind power generators were analyzed according to the porosity and height of the parapet installed in the rooftop layer. The wind speed at the top was decreasing as the parapet was installed. However, the wind speed reduction effect was decreasing as the porosity rate increased. In addition, the increase in porosity significantly reduced turbulence intensity and reduced it by up to 40% compared to no railing. In the case of parapets with sufficient porosity, the effect of reducing turbulence intensity was also increased as the height increased. Therefore, it was confirmed that sufficient parapet height and high porosity reduce the effect of reducing wind speed by parapets and significantly reducing the turbulence intensity, which can provide homogeneous wind speed during installation of wind power generators.


2015 ◽  
Vol 8 (5) ◽  
pp. 1935-1949 ◽  
Author(s):  
A. Kylling ◽  
N. Kristiansen ◽  
A. Stohl ◽  
R. Buras-Schnell ◽  
C. Emde ◽  
...  

Abstract. Volcanic ash is commonly observed by infrared detectors on board Earth-orbiting satellites. In the presence of ice and/or liquid-water clouds, the detected volcanic ash signature may be altered. In this paper the sensitivity of detection and retrieval of volcanic ash to the presence of ice and liquid-water clouds was quantified by simulating synthetic equivalents to satellite infrared images with a 3-D radiative transfer model. The sensitivity study was made for the two recent eruptions of Eyjafjallajökull (2010) and Grímsvötn (2011) using realistic water and ice clouds and volcanic ash clouds. The water and ice clouds were taken from European Centre for Medium-Range Weather Forecast (ECMWF) analysis data and the volcanic ash cloud fields from simulations by the Lagrangian particle dispersion model FLEXPART. The radiative transfer simulations were made both with and without ice and liquid-water clouds for the geometry and channels of the Spinning Enhanced Visible and Infrared Imager (SEVIRI). The synthetic SEVIRI images were used as input to standard reverse absorption ash detection and retrieval methods. Ice and liquid-water clouds were on average found to reduce the number of detected ash-affected pixels by 6–12%. However, the effect was highly variable and for individual scenes up to 40% of pixels with mass loading >0.2 g m−2 could not be detected due to the presence of water and ice clouds. For coincident pixels, i.e. pixels where ash was both present in the FLEXPART (hereafter referred to as "Flexpart") simulation and detected by the algorithm, the presence of clouds overall increased the retrieved mean mass loading for the Eyjafjallajökull (2010) eruption by about 13%, while for the Grímsvötn (2011) eruption ash-mass loadings the effect was a 4% decrease of the retrieved ash-mass loading. However, larger differences were seen between scenes (standard deviations of ±30 and ±20% for Eyjafjallajökull and Grímsvötn, respectively) and even larger ones within scenes. The impact of ice and liquid-water clouds on the detection and retrieval of volcanic ash, implies that to fully appreciate the location and amount of ash, hyperspectral and spectral band measurements by satellite instruments should be combined with ash dispersion modelling.


2001 ◽  
Vol 47 (2) ◽  
pp. 411-418 ◽  
Author(s):  
Makiko Watanabe ◽  
Nobuhide Fujitake ◽  
Hiroyuki Ohta ◽  
Takushi Yokoyama

2013 ◽  
Vol 365-366 ◽  
pp. 978-982
Author(s):  
Xiao Wei Feng ◽  
De Wen Zhang

The softening point of modified asphalt is an extremely important indicator to evaluate the high-temperature performance; its the temperature of modified asphalt sample emerging shear deformation under the action of certain shear stress according to the specific heating rate. Its found that in the actual construction and testing, different temperature conditions has a larger impact on the softening point of the modified asphalt, which has adverse affect on road construction. This paper studied and researched the influence of temperature on modified asphalt softening point indicators from the different test temperature, including packing compact temperature, scraper temperature in removal of asphalt that above test mode, standing temperature, curing temperature and initial heating temperature before test.


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