1) Demolition projects are becoming more complicated due to modern construction techniques and increased safety regulations. 2) Applied Science International helps demolition contractors overcome these challenges by simulating demolition plans using structural analysis software. 3) Their simulations model the entire structure and calculate how it will fail and collapse piece by piece, allowing contractors to safely test different demolition approaches.
The effect of ethanol extract of leaves of Conyza Dicorides plant on the corrosion inhibition
of mild steel in 1M HCl solution was investigated by weight loss and electrochemical polarization
techniques at temperature range (25–65 ̊C). The Results obtained showed that the percentage
inhibition efficiency increases with the increasing of inhibitor concentration and decreases with the
increasing of temperature. At a concentration of 2 g/L, the percentage inhibition efficiency reached
about (94.87%) at 25 ̊C. The thermodynamic activation functions of dissolution process and
adsorption parameters were calculated and discussed. Adsorption of the additive was found to follow
the Langmuir adsorption isotherm.
Leigh-Ann Harris
Junior Research Officer,
Centre for Ergonomics, Occupational Safety and Health, School of Management,
Massey University,
Private Bag 11 222, Palmerston North
L.A.Harris@massey.ac.nz
(P47, Friday 28, Civic Room 1, 3.00)
Best Practices for Maintenance
Properly selected and installed motors can operate for many years with minimal maintenance. Nonetheless, regular care will extend their life and maximize their energy efficiency.
The effect of ethanol extract of leaves of Conyza Dicorides plant on the corrosion inhibition
of mild steel in 1M HCl solution was investigated by weight loss and electrochemical polarization
techniques at temperature range (25–65 ̊C). The Results obtained showed that the percentage
inhibition efficiency increases with the increasing of inhibitor concentration and decreases with the
increasing of temperature. At a concentration of 2 g/L, the percentage inhibition efficiency reached
about (94.87%) at 25 ̊C. The thermodynamic activation functions of dissolution process and
adsorption parameters were calculated and discussed. Adsorption of the additive was found to follow
the Langmuir adsorption isotherm.
Leigh-Ann Harris
Junior Research Officer,
Centre for Ergonomics, Occupational Safety and Health, School of Management,
Massey University,
Private Bag 11 222, Palmerston North
L.A.Harris@massey.ac.nz
(P47, Friday 28, Civic Room 1, 3.00)
Best Practices for Maintenance
Properly selected and installed motors can operate for many years with minimal maintenance. Nonetheless, regular care will extend their life and maximize their energy efficiency.
:Why Occupational safety,Important factors of Occupational safety in Agriculture.causes and common types of accidents.Occupational safety is very important and it is the joint responsibility of all: the government,the employer and the worker.
Descriptive study of pushover analysis in rcc structures of rigid jointYousuf Dinar
ABSTRACT: Structures in mega cities, are under serious threat because of faulty and unskilled design and construction of structures. Sometimes structure designers are more concerned in constructing different load resistant members without knowing its necessity and its performance in the structure. Different configuration of construction may also lead to significant variation in capacity of the same structure. Nonlinear static pushover analysis provides a better view on the performance of the structures during seismic events. This comprehensive research evaluates as well as compares the performances of bare, different infill percentage level, different configuration of soft storey and Shear wall consisting building structures with each other and later depending upon the findings, suggests from which level of performance shear wall should be preferred over the infill structure and will eventually help engineers to decide where generally the soft storey could be constructed in the structures. Above all a better of effects of pushover analysis could be summarized from the findings. Masonry walls are represented by equivalent strut according to pushover concerned codes. For different loading conditions, the performances of structures are evaluated with the help of performance point, base shear, top displacement, storey drift and stages of number of hinges form.
Performance based analysis of rc building consisting shear wall and varying i...Yousuf Dinar
Abstract:
Metropolitan cities are under severe threat because of inappropriate design and construction of structures. Faulty building designed without considering seismic consideration could be vulnerable to damage even under low levels of ground shaking from distant earthquake. So, structural engineers often are more concerned about the constructing Shear wall without knowing its performance with respect to infill percentage which may lead it to an over design state without knowing the demand. Nonlinear inelastic pushover analysis provides a better view about the behavior of the structures during seismic events. This study investigates as well as compares the performances of bare, different infill percentage level and two types of Shear wall consisting building structures and suggests from which level of performance shear wall should be preferred over the infill structure. To perform the finite element simulation ETABS 9.7.2 is used to get the output using pushover analysis. For different loading conditions, the performances of structures are evaluated with the help of base shear, deflection, storey drift, storey drift ratio and stages of number of hinges form and represented with discussion.
GIRDER DESIGN OF A BALANCED CANTILEVER BRIDGE WITH ANALYSIS USING MIDAS CIVILAM Publications
Balanced cantilever bridges are used for special requirements like 1) Construction over traffic 2) Short lead time compared to steel 3) Use local labour and materials. If continuous spans are used, the governing bending moment can minimised and hence the individual span length can increase. But unyielding supports are required for continuous construction. Hence for the medium span in the range of about 35 to 60 m, a combination of supported span, cantilever and suspended span can be adopted and bridge with this type of superstructure is known as balanced cantilever bridge. This chapter include the analysis and design of a 50m span prestressed balanced cantilever bridge which comprises of 6 numbers of Pre-Cast Post Tensioned-I Girder 38m long Simply Supported at one end and connected through a Cast-in-Situ Stitch Concrete to a Continuous Balanced Cantilever Box Girder (2x11m). The bridge structure has been modelled by Finite element Technique using MIDAS Civil and analysis has been performed to get various output such as primary and secondary bending moment, shear forces and torsion quantities at various locations of the bridge. The design of super structure is performed as per IRC standards.
GIRDER DESIGN OF A BALANCED CANTILEVER BRIDGE WITH ANALYSIS USING MIDAS CIVILAM Publications
Balanced cantilever bridges are used for special requirements like 1) Construction over traffic 2) Short lead time compared to steel 3) Use local labour and materials. If continuous spans are used, the governing bending moment can minimised and hence the individual span length can increase. But unyielding supports are required for continuous construction. Hence for the medium span in the range of about 35 to 60 m, a combination of supported span, cantilever and suspended span can be adopted and bridge with this type of superstructure is known as balanced cantilever bridge. This chapter include the analysis and design of a 50m span prestressed balanced cantilever bridge which comprises of 6 numbers of Pre-Cast Post Tensioned-I Girder 38m long Simply Supported at one end and connected through a Cast-in-Situ Stitch Concrete to a Continuous Balanced Cantilever Box Girder (2x11m). The bridge structure has been modelled by Finite element Technique using MIDAS Civil and analysis has been performed to get various output such as primary and secondary bending moment, shear forces and torsion quantities at various locations of the bridge. The design of super structure is performed as per IRC standards.
:Why Occupational safety,Important factors of Occupational safety in Agriculture.causes and common types of accidents.Occupational safety is very important and it is the joint responsibility of all: the government,the employer and the worker.
Descriptive study of pushover analysis in rcc structures of rigid jointYousuf Dinar
ABSTRACT: Structures in mega cities, are under serious threat because of faulty and unskilled design and construction of structures. Sometimes structure designers are more concerned in constructing different load resistant members without knowing its necessity and its performance in the structure. Different configuration of construction may also lead to significant variation in capacity of the same structure. Nonlinear static pushover analysis provides a better view on the performance of the structures during seismic events. This comprehensive research evaluates as well as compares the performances of bare, different infill percentage level, different configuration of soft storey and Shear wall consisting building structures with each other and later depending upon the findings, suggests from which level of performance shear wall should be preferred over the infill structure and will eventually help engineers to decide where generally the soft storey could be constructed in the structures. Above all a better of effects of pushover analysis could be summarized from the findings. Masonry walls are represented by equivalent strut according to pushover concerned codes. For different loading conditions, the performances of structures are evaluated with the help of performance point, base shear, top displacement, storey drift and stages of number of hinges form.
Performance based analysis of rc building consisting shear wall and varying i...Yousuf Dinar
Abstract:
Metropolitan cities are under severe threat because of inappropriate design and construction of structures. Faulty building designed without considering seismic consideration could be vulnerable to damage even under low levels of ground shaking from distant earthquake. So, structural engineers often are more concerned about the constructing Shear wall without knowing its performance with respect to infill percentage which may lead it to an over design state without knowing the demand. Nonlinear inelastic pushover analysis provides a better view about the behavior of the structures during seismic events. This study investigates as well as compares the performances of bare, different infill percentage level and two types of Shear wall consisting building structures and suggests from which level of performance shear wall should be preferred over the infill structure. To perform the finite element simulation ETABS 9.7.2 is used to get the output using pushover analysis. For different loading conditions, the performances of structures are evaluated with the help of base shear, deflection, storey drift, storey drift ratio and stages of number of hinges form and represented with discussion.
GIRDER DESIGN OF A BALANCED CANTILEVER BRIDGE WITH ANALYSIS USING MIDAS CIVILAM Publications
Balanced cantilever bridges are used for special requirements like 1) Construction over traffic 2) Short lead time compared to steel 3) Use local labour and materials. If continuous spans are used, the governing bending moment can minimised and hence the individual span length can increase. But unyielding supports are required for continuous construction. Hence for the medium span in the range of about 35 to 60 m, a combination of supported span, cantilever and suspended span can be adopted and bridge with this type of superstructure is known as balanced cantilever bridge. This chapter include the analysis and design of a 50m span prestressed balanced cantilever bridge which comprises of 6 numbers of Pre-Cast Post Tensioned-I Girder 38m long Simply Supported at one end and connected through a Cast-in-Situ Stitch Concrete to a Continuous Balanced Cantilever Box Girder (2x11m). The bridge structure has been modelled by Finite element Technique using MIDAS Civil and analysis has been performed to get various output such as primary and secondary bending moment, shear forces and torsion quantities at various locations of the bridge. The design of super structure is performed as per IRC standards.
GIRDER DESIGN OF A BALANCED CANTILEVER BRIDGE WITH ANALYSIS USING MIDAS CIVILAM Publications
Balanced cantilever bridges are used for special requirements like 1) Construction over traffic 2) Short lead time compared to steel 3) Use local labour and materials. If continuous spans are used, the governing bending moment can minimised and hence the individual span length can increase. But unyielding supports are required for continuous construction. Hence for the medium span in the range of about 35 to 60 m, a combination of supported span, cantilever and suspended span can be adopted and bridge with this type of superstructure is known as balanced cantilever bridge. This chapter include the analysis and design of a 50m span prestressed balanced cantilever bridge which comprises of 6 numbers of Pre-Cast Post Tensioned-I Girder 38m long Simply Supported at one end and connected through a Cast-in-Situ Stitch Concrete to a Continuous Balanced Cantilever Box Girder (2x11m). The bridge structure has been modelled by Finite element Technique using MIDAS Civil and analysis has been performed to get various output such as primary and secondary bending moment, shear forces and torsion quantities at various locations of the bridge. The design of super structure is performed as per IRC standards.
Assessment of seismic damage of multistory structures using fragility curvesIJERA Editor
Performance-based design, PBD, is gaining popularity and its concept hasbeen applied in many international
seismic building codes. In this research, five real structures designed according to the Egyptian Building Code,
which does not consider PBD, are considered and modeled in a three dimensional way using the software
SeismoStruct in order to assess their performance under expected earthquakes. The structures are 2-story, 4-
story, 6-story, 8-story and 10-story reinforced concrete framed structures. The structural system of these
structures is of the moment-resisting frame type, with and without shear walls. The structures weredesigned
under dead, live and seismic forces of “Zone 3” with a design acceleration of 0.15g.The models were analyzed
using incremental dynamic analysis, IDA, considering 12 real records of historical earthquakes. IDA curves
were developed for all analyzed models, considering four damage states. Fragility curves were subsequently
developed to provide an overview of the expected seismic performance of a typical low or mid-rise multistory
reinforced concrete framed structure in Egypt as designed in accordance with thecurrent Egyptian Building
Code.
Assessment of seismic damage of multistory structures using fragility curvesIJERA Editor
Performance-based design, PBD, is gaining popularity and its concept hasbeen applied in many international
seismic building codes. In this research, five real structures designed according to the Egyptian Building Code,
which does not consider PBD, are considered and modeled in a three dimensional way using the software
SeismoStruct in order to assess their performance under expected earthquakes. The structures are 2-story, 4-
story, 6-story, 8-story and 10-story reinforced concrete framed structures. The structural system of these
structures is of the moment-resisting frame type, with and without shear walls. The structures weredesigned
under dead, live and seismic forces of “Zone 3” with a design acceleration of 0.15g.The models were analyzed
using incremental dynamic analysis, IDA, considering 12 real records of historical earthquakes. IDA curves
were developed for all analyzed models, considering four damage states. Fragility curves were subsequently
developed to provide an overview of the expected seismic performance of a typical low or mid-rise multistory
reinforced concrete framed structure in Egypt as designed in accordance with thecurrent Egyptian Building
Code.
IRJET- A Review on Progressive Collapse of Composites Structures
Demolition Analysis Article
1. DEMOLITION ENGINEER Autumn 2007
8
DEMOLITION ENGINEER Autumn 2007
9
Demolition is becoming ever more
complicated because of both
modern structural systems and
additional safety regulations. As a
result, many demolition
contractors and municipalities are
looking for ways to overcome
these challenges.
Until recently technical limitations prevented the
accurate calculation and presentation of
structural behaviour during post-failure stages
and collapse. Therefore, simulating demolition
plans has not been a viable option.
However, Applied Science International (ASI),
an engineering analysis firm based in the United
States, is helping demolition contractors by
simulating and visualising their plans using
Extreme Loading® analysis technology.
Extreme Loading® an exclusive technology
based on the Applied Element Method (AEM)
analyses a structure’s behaviour during pre- and
post-failure stages in 3D, in addition to
calculating changes in the structure as elements
fail, tracking the propagation of cracks, and
simulating progressive collapse.
COLLAPSE BEHAVIOUR
Recognising value in the capabilities of this
technology engineers, security experts, and over
50 universities worldwide are using Extreme
Loading® analysis to study concrete, steel,
masonry and composite structures under
extreme events such as explosions, earthquakes,
hurricanes, impact, and demolition.
“Demolition contractors are facing more
challenges with projects in dense urban
environments, and the ageing of complex
structures. Safety and quality standards are
requiring additional analysis of demolition plans.
That’s where our simulations can help,” says
Steve Bruns, business development manager for
ASI. “By modeling a structure and then running
the demolition plan, we can generate simulations
that allow demolition contractors to test several
different plans and ‘What-if’ scenarios to identify
safety perimeters, and communicate their plans.”
ASI’s demolition simulations replicate each
element of the structure to determine its
behaviour during demolition and collapse. This
reveals the collapse behaviour of composites,
post-tensioned elements, precast elements, rebar,
concrete strength, and structural deterioration.
When there is a concern for the contribution of
nonstructural elements during demolition, walls,
elevator shafts, and windows are modeled into
the analysis and their effects on the demolition
are also simulated.
ASI’s simulation capabilities have primarily
attracted explosive demolition projects because of
the associated risk but the scope of applications
include: pull downs, wrecking ball, and
deconstruction projects.
EXTREME LOADING
For example in deconstruction projects ASI
simulates how a building behaves when heavy
equipment, often exceeding the weight limits of a
building, removes portions of a building piece by
piece creating a potentially unstable and
dangerous environment. Extreme Loading®
technology simulates the sequence of removing
structural members and the movement of the
equipment within the building to illustrate the
impact on the remaining supports. Diagrams of
colour contours are generated representing the
changes in stresses and strain on the structure,
and highlighting zones where there is risk of
sudden collapse.
Last month the world‘s largest domed arena at
time of construction ‘the Hive’ former home of
the Charlotte Hornets basketball team was taken
down by explosive demolition. The 24,000 seat
arena was built of steel, composite columns,
composite girders, masonry walls, and a dome
made from an intricate web of space trusses. The
primary challenge facing the demolition
contractor was weakening the dome truss so that
it remains intact during the demolition long
enough for it to pull the perimeter of the
coliseum inward as the supporting columns are
blasted. Any mistake in the plan would have
significantly increased removal time and costs.
BLAST SPECIALISTS
ASI studied the case from every angle, examining
the structure’s main elements and gathering
information from blueprints and site visits.
“We modeled the coliseum including its steel and
composite sections, space trusses, reinforcement
details, and even compensated for deterioration.”
“We also modeled the plans for weakening the
structure, modeling all the cuts in the steel
columns and trusses,” says Patrick Lea, ASI
structural engineer.
The blast plan was modeled into the computer
simulation by using a method called immaculate
element removal. This method is to remove
elements from the model in the same sequence
the blast specialist would detonate the charges.
The program then runs computations to
determine the overall behaviour of the structure.
The project took about three weeks to complete
from start to finish.
“We were able to illustrate the collapse mode and
debris field to the owners and help the blaster
adjust the sequence to maintain momentum thru
the collapse and bring the dome down more
completely,” says Patrick.
When the video of the real implosion and simulation
were compared, (http://www.appliedscienceint.com/
Charlotte Coliseum.shtml#Movie) it was immediately
evident that the simulation accurately resembled the
actual implosion.
EVENT ATTRACTION
Events like this also draw significant attention
from the media who now have the ability to see
beyond the dust of the actual demolition and
inside the structure as it collapses.
Lately, ASI has been working closely with
engineers on planning the demolition of an
industrial facility in Australia. The facility, retired
over three years ago, is five meters away from a
reactor that must remain standing after the
demolition. The challenge is in the structure’s
complex braced frame used to support large
industrial equipment much of which will remain,
and to provide a stable base until the final stage
at which point complete structural collapse is
required. The consulting engineers were limited
to using linear static finite element analysis to
study the demolition plans, which cannot
determine collapse modes. ASI was hired to help
calculate the required pulling force to bring down
the structure safely, determine the dynamic
behaviour, and simulate collapse modes. ASI is
testing multiple scenarios and the final
demolition plan is in the works.
CATCHING UP WITH THE
FUTURE
Demolition is known to accelerate the future;
finally, the future has caught up with demolition.
By using computer simulations to visualise
demolition plans, demolition safety standards
have been elevated to new heights.
See the simulation of the Charlotte Coliseum
and find updates about the Australia project at
ASI’s website: www.extremeloading.com.
See it come down…before it comes down