Vol. 8(1) January 2015
Tropical Storm Sarika merging in Typhoon Songda Circulation
by Strong Wind and Sufficient Moisture Transportation
Choi Hyo and Lee Mi Sook
The destruction of a small tropical storm pulled by a
stronger typhoon was investigated using GOES-9 IR satellite images, weather maps
and numerically calculated moisture fluxes and streamlines with strong wind bands
by a meteorological model - the UM (British Unified Model) adopted by Korean Meteorological
Administration (UM-KMA) from September 5 through 8, 2004. When Typhoon Songda- TY
0418 of 940hPa with a maximum surface wind speed of 80kts moved north-northwestward
with its slow moving speed of 6kt at 00:00 LST, September 6, another severe Tropical
Storm Sarika-STS 0419 of 980hPa with a maximum surface wind speed of 55kts was detected
at 142.7°E and 19.3°N, showing its westward movement of 14kts.
Streamline and moisture flux at 850hPa level showed that Sarika maintaining an independent
moving track before had an interaction with Sonda, especially its right quadrant
of cyclonic circulation at 09:00LST September 6 and from 09:00LST September 7, persistent
westward STS Sarika was strongly pulled north by northeastward TY Songda with a
maximum surface wind of 80kts and its moving speed of 21kts and Sarika could be
drawn into the wake of Songda’s main streamline. Due to the prohibition of Songda,
the cyclonic circulation of Sarika was destroyed from 21:00LST, September 7 and
eventually there must have been a reduction in its strength, showing no longer tightly
packed bands of cloud and spreading of clouds, that is, becoming extinct. The moisture
transportation from tropical storm into stronger typhoon could cause a significant
weakness of tropical storm and gradually disappeared.
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Flexural performance of prestressed UHPC beams with
HRB500 rebars
Deng Zongcai*, Gao Lei and Jumbe R. Daud
In order to investigate the feasibility of high strength
rebars used in UHPC reinforcement, a flexural performance experiment of prestressed
beams was conducted. The variable parameters investigated include: type of non-prestressed
rebars, reinforcement ratio and level of prestress. Experiment results show that
increasing the prestressing reinforcement ratio or prestress control value of the
tendons can significantly improve the beams crack resistance. Higher prestressing
level can be achieved for UHPC beams reinforced with HRB500 unlike conventional
concrete. HRB500 rebar has little effect on cracking load but significantly improves
the yield and ultimate loads since its excellent properties are fully utilized.
Comparing beams reinforced with HRB500 and beams with HRB335 reinforcement, denser
microcracks are formed for UHPC beams with HRB500, moreover crack propagation is
slower and crack width is smaller, not exceeding 0.15mm in serviceability limit
state. Considering the influence of fiber reinforced UHPC plastic deformation on
the stress distribution, a formula for the calculation of the initial cracking load
was established. From the simplified UHPC constitutive model, the stress in the
tension and compression zone is calculated according to the equivalent rectangular
concrete stress distribution. The calculated and the experimental values of the
bending capacity are in good agreement, and can provide reference for the theoretic
analysis and design of UHPC beams.
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Impact of blast-induced vibration on tunnel supports
Jeon Sang-Soo
This study considered the effects of blast vibrations
induced by explosions of powder on adjacent tunnels. The behaviors of the tunnel
supports including the concrete lining and rock bolts installed in the tunnel were
examined with respect to the loading density of the explosive charges and the peak
particle velocity (PPV). Additionally, the resisting shear stress, bending compressive
stress and axial forces of the tunnel supports upon application of blast loading
to the tunnel were studied. A two-dimensional finite difference model was adopted
for the numerical analysis. The analysis results showed that the resisting bending
compressive stress and shear stress of the concrete lining and the axial force of
the rock bolt at the crown of the tunnel increase rapidly upon application of blasting
load adjacent to the tunnel. Furthermore, the blast-induced vibration effect on
the shear stress of the concrete lining is substantially larger than that on the
bending compressive stress.
Finally, both the bending compressive stress and shear stress mobilized at the concrete
lining and the axial force mobilized at the rock bolts increase linearly with respect
to increasing PPV values.
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Possible approach for interlinking of ponds-to mitigate
drought in Sivaganga villages at micro level
Manikandan S.*, Indiramma P. and Rajesh J.
This paper presents the results of our studies concerning
the implementation and exploitation of Geographical Information System (GIS) dedicated
to the support and assistance of decisions requested by drought management. In this
study on diverting of surplus water through canals, ponds and check dams in the
study area was carried out. The remote sensing data and GIS data was used to identify
the drought prone villages in Sivaganga taluk and to generate present landuse, drainage
pattern as well as slope and contour. This analysis was carried out for diverting
surplus water through proposed canal and pond.
The results of the study indicate that if the surplus water from the ponds and streams
are diverted to the drought villages in Sivaganga taluk, it will definitely improve
the agricultural production due to availability of water in the ponds. The improvements
in agricultural production will help to improve the economical condition of the
farmers in the region.
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3D Computer Modeling of the catastrophic collapse
of Fiber Reinforced Concrete structures
Horta-Rangel J., Perez-Rea L., Rojas-Gonzalez E., Lopez-Lara T., Hernandez-Zaragoza
J. and Castano V.M.*
A computer-based analysis of a Fiber Reinforced Concrete
Composite (FRCC), with steel fibers under catastrophic collapse conditions was carried
out. Composite models are subjected to tensile stresses under quasi-static loads
until the catastrophic failure. Of great relevance is the random fiber distribution
within the composite and their fully integration into the concrete matrix. An algorithm
was developed that generates the fibers in three levels of random location by using
local spherical coordinates.
Research was carried out on volumetric composites taking into account 3D random
fibers distribution. Composites are analyzed under different percentages of volume
fiber highlighting the peculiarities of each case. The analysis involves a charge-discharge
process monitoring the nonlinear behavior of the composite, as well the evolution
of cracks and collapse of the composite. The failure process and collapse was done
by using finite elements Birth and Death which are able to modify their properties
when they reach a critic tensile stress inside the concrete matrix.
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Features and the genetic mechanism of Shuanghe giant
landslide in Jiuzhai, Sichuan, China
Xin Zhang, Yunsheng Wang*, Xinze Li, Yusheng Li, Ge Gao and Qing Quan
The Jiuzhai County is located in area of the northwest
of Sichuan Province with high seismic intensity. There were a series of huge landslide
damming events in the geological history providing beautiful lake or a wide valley
in the reservoir. Shuanghe landslide is one among them. The mechanism study of the
landslide is the key to the future similar slope stability in the region. Based
on the large scale geological survey, drilling and time dating, it reveals that
the landslide is located in the right bank of Baishuijiang River, its source region
is the high slope with counter-tilt structure, the regional maximum geo-stress is
perpendicular to the flow direction of Baishuijiang River, since the middle Pleistocene,
the river has cut intensively, the intensive unloading and the stress field adjustment
resulted in obvious toppling deformation in the high slope and a huge rock landslide
was triggered by a strong earthquake in 30000 years ago, it overlapped over the
second terrace, the accumulation is composed of huge block with a volume about 250
million m3, it dammed the river for a long time, forming a reservoir and then it
broke, then left a wide valley in the reservoir.
The main part of Shuanghe landslide is stable and the front part can be reactive
due to the river lateral erosion in the toe of the landslide accumulation. The environmental
effects can be concluded: there is a wide valley in the ever-reservoir area providing
the people with a satisfied site for new county town construction; as the lacustrine
silt sediments beneath the new county town, the bearing capacity and sand liquefaction
exist; the narrow valley in the front of the landslide, as the road construction
cutting at the toe, the front part of the landslide can survive in the future which
may dam the river again which could threaten the new county town.
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Land use / land cover change detection analysis in
Salem Chalk Hills, South India using remote sensing and GIS
Thilagavathi N.*, Subramani T. and Suresh M.
Salem Chalk Hills, Tamil Nadu, India lies amidst the
mineral rich geological formation. The region has been experiencing a lot of land
use/land cover changes induced by both people and industries in recent years following
the exploitation of different minerals. The overburden of mines when dumped in unmined
areas creates mine spoils which ultimately affect the surrounding. This study sought
to determine the rate of land cover changes that occurred in Salem Chalk Hills region
since 2002. This was achieved through the use of satellite image of LANDSAT TM and
IRS P6 LISS IV MX. Therefore, present study has been undertaken to analyze the process
of humaninduced landscape transformation in the mine affected areas of Chalk Hills
of Salem by interpreting temporal remote sensing data for the year 2002 and 2012
using GIS.
Land use changes have been detected by image processing techniques. Field observation
and measurements have also employed to validate results from remotely sensed data.
Results show that the rate of land use/ land cover change has been significant and
it is due to mining activities. This accelerated change is mainly attributing to
cultivation. It has been observed that there are significant changes especially
in agricultural land and built-up area. During 2002 buildup land is 11.24 km2 and
it is increased as 44.28 km2 (11.60%) in 2012.
The area of water body has been shrunk by about 0.38%. Changes in the agricultural
lands are related to urban population growth of the study area. The expansion of
build up lands and urban areas and contraction of agricultural land and water bodies
leads to environmental degradation in the form of soil erosion. Similarly land with
scrub decreased and land without scrub is increased.
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Decontamination-oriented Reconstruction Policy in
Fukushima Post 3.11: Real versus Administrative Boundaries
Fujimoto Noritsugu
This study distinguishes between the “real area” that
was affected by the Tohoku-Pacific Ocean Earthquake and the Fukushima Daiichi nuclear
plant explosion in the “administrative district,” which is governed by the central,
prefectural and city governments. The former area can be defined as “the zone contaminated
by radioactive substances in the soil after the Fukushima Daiichi nuclear disaster.”
The latter describes “the district that is legally governed by a three-layer government
comprising a central government bureau, a prefectural self-governing body and the
municipality (cities, towns, and villages) that provides public services for citizens.”
However, the second description of Fukushima seems to overpower the first in a systematic
and purposeful manner. The government has sought to avoid comprehensive monitoring
and information disclosure of the radioactive contamination because they would like
to dismiss concerns regarding radioactive contamination from the nuclear plant accident.
As of July 30, 2014, some parts of Fukushima Prefecture remain exposed to high-level
radiation that exceeds the standard for radiation-controlled areas (5.2 m Sv per
year). Other areas do not suffer any direct damage from the accident. Despite the
fact that Fukushima includes both areas, governing bodies have failed to produce
a contamination map that incorporates the entire prefecture. They have only disclosed
the radioactive pollution measurement results from the centers of the prefecture’s
cities, towns and villages for the fear of both compensation claims and reputation.
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