Measurement is one of the most important things in civil engineering and without measurements, we can not complete any construction. Here I have listed some basic measurements and conversion factors which are most commonly used in civil engineering. Hope it will help you in your work.
Too much salt can raise blood pressure, which is a leading risk factor for heart disease and stroke.
Eating salt raises the amount of sodium in your bloodstream and wrecks the delicate balance, reducing the ability of your kidneys to remove the water. The result is a higher blood pressure due to the extra fluid and extra strain on the delicate blood vessels leading to the kidneys.
Two fragments of a
3,800-year-old clay tablet show a collection of geometry exercises and
questions in Akkadian script that would have confronted young Babylonian
scholars. Here students are asked to calculate the areas of various
subdivisions of squares.
The British Museum.
We may talk about mental and physical health as two separate things
but, in reality, they’re interconnected. Felicity Pienaar, an
Occupational Therapist at Akeso Clinic in Nelspruit, explains that
patients with poor mental health often lack energy and feel too unwell
to take care of their basic needs, like healthy eating, quality sleep,
and exercise. Further, she says anxiety and stress can lead to physical
complaints, like headaches, back and neck pain, and insomnia.
According to the Canadian Mental Health Association (2018),
people with serious mental health conditions run a high risk of
experiencing chronic physical conditions, but people with chronic
physical conditions are also at risk of poor mental health. What this
suggests is that mental and physical health are so interlinked, it’s
impossible to separate them. No wonder the World Health Organization
says “there is no health without mental health”.
Society’s bad mental habits
The current mental health epidemic isn’t only on the individual
level. Pienaar says there are several societal behaviours that also have
an impact. We’re seeing this in three major ways:
1.Fast and slow lifestyles
Our desk-bound lifestyles mean we’re not getting the exercise our
bodies and minds need. Couple that with fast food, a technologically
enhanced culture of instant gratification, long working hours, and
smart-phone-diluted leisure time, and we’re starting to resemble lab
rats.
2.Moral degradation
Society’s growing desensitisation to things like infidelity,
materialism, and disrespect for others, is contributing to serious
emotional harm. In fact, researcher, Richard Eckersley (2006) says that
“materialism is associated, not with happiness, but with
dissatisfaction, depression, anxiety, anger, isolation, and alienation.”
3.The overuse of tech
Perhaps the most dangerous, yet largely under-addressed
habit we’re practising daily is overusing our smart-phones and
computers. Psychiatrist and author Victoria L. Dunckley (2014) says this
is a problem because overexposure to screens can have a significant
effect on our brain’s structure and function – especially in the frontal
lobe.
This area of the brain undergoes massive changes until the
mid-twenties, and is said to impact on all areas of life – from
relationships to career and academic success.
Symptoms to look out for
About a third of the South African population will suffer from a
mental disorder in their adult lives, says Africa Check (2014). Pienaar
says the most common conditions seen at Akeso include mood disorders
like depression, substance abuse, bipolar mood disorder, or those
suffering from symptoms related to anxiety and stress. Typical symptoms
can include:
Chronic fatigue
Impulsive behaviour
Low or fluctuating moods
Poor interpersonal relationships
Disinterest in most aspects of life
Managing mental self-care
Apart from critical professional guidance, there are many physical
and mental behaviours you can adopt to help improve your psychological
wellbeing. Pienaar recommends:
Exercising
Getting enough sleep
Spending time alone
Connecting with family and friends
Practicing deep, calming breathing
Spending less time using electronic devices
Forgiving yourself when you make mistakes
Paying attention to and expressing your feelings
Limiting your intake of alcohol, caffeine, and other drugs
Taking prescribed medication, even when your symptoms improve
While these are helpful first steps, it’s important to note that
nothing compares to professional support – especially if your symptoms
affect your life and those around you.
Where and how to get help
If you suspect that you’re suffering from a mental health condition,
reach out to supportive family or friends and see a professional as soon
as possible. The South African Depression and Anxiety Group (SADAG)
provides a list of valuable online videos that can help you to better
understand common mental disorders and how they may affect you.
If you’re not coping, and especially if you feel suicidal, Marie
Claire (2017) provides a great list of contact centres to call. We’ve
provided a list at the end of this article.
It’s not easy to jump-start your mental wellbeing, but at least you
don’t have to do it alone. There are people who are ready and willing to
guide and support you through it. Call them.
Large numbers are numbers that are significantly larger than those ordinarily used in everyday life, for instance in simple counting or in monetary transactions. The term typically refers to large positive integers, or more generally, large positive real numbers, but it may also be used in other contexts.
Very large numbers often occur in fields such as mathematics, cosmology, cryptography, and statistical mechanics. Sometimes people refer to numbers as being "astronomically large". However, it is easy to mathematically define numbers that are much larger even than those used in astronomy.
Situated at an altitude of 3,584 m, Kedarnath Temple is one of the holiest Hindu pilgrimage destinations in the Rudraprayag district of Uttarakhand. This holy town is situated in the Garhwal Himalayas and lies among the magnificent snow-covered mountains. Kedarnath is famous for the ancient shrine dedicated to Lord Shiva which is visited by thousands of devotees every year. Mandakini River flows near the Kedarnath. Kedarnath Temple remains closed during winter, as the region experiences heavy snowfall. During this time, Lord Kedarnath’s Palki is shifted to its winter seat at Ukhimath. This holy town offers the panoramic view of magnificent mountain peaks, splendid landscape, ponds and streams, and sparkling water of River Mandakini.
The lower part of the village the Underground Church of St Jean, also known as the Monolithic church, Eglise Monolithique, or the troglodyte church is outstanding. The church has been carved out of the rock and inside is enormous. The height reaches to 20 meters at its highest - taller than that of St Emillion. Indeed the Monolithic church of Aubeterre sur Dronne is the tallest in the world. (St Emillion's, though not as tall, is the largest in Europe).
The church was hidden for years by a large rock fall and only rediscovered in the 1950s.
Since the use of first simple bridges made from a single beam that had to
endure all the forces of tension, compression, torsion and shear forces by
itself, engineers and architects tried to develop new and better techniques
for spanning the gaps between one point of terrain to another. Eventually,
the entire engineering field was formed, and dozens upon dozens of bridge
designs were created utilizing many components, parts and brand new
terminology that describe them.
All the basic components are placed inside three main bridge areas –
Foundation (which holds the shallow or deep base of the
bridge and transfers it’s load to the bearing strata, this includes
foundations below the main span of the bridge and the abutments below
starting points of the bridge),
Substructure (piers,
abutments, spandrels, caps, bearings, and other components that holds the
upper construction) and
Superstructure (all the parts of
the bridge that are mounted on top of the supporting substructure system,
it covers elements such as decking, girders, slab, and everything placed
above the main deck such as posts, steel truss system, bridge girder,
cable-stayed system, cable suspended systems and more).
Basic Components and Parts of Bridge Structures
The bridge structure consists of the following components:
Superstructure or decking component
Bearings
Substructure Components
Fig: Semi-Through Section of a Concrete Slab Road Bridge
Superstructure Components of Bridges
The
superstructure of the bridge structure consists of deck slab, girder,
truss etc. These components vary based on the type of bridge (whether
concrete or steel or composite). Superstructure of the bridge bears the
load passing over it. This helps in transmitting the forces formed by
the loads to the below substructures.
Decks
The
decking is considered as the road or the rail surface of the bridge. The
decks are supported by the girders or the huge beams that is in turn
supported by the piers. The whole arrangement is supported with a deep
foundation mainly piles and cap arrangement.
Bearings in Bridges
The
loads received by the decks are properly and safely transmitted to the
substructure with the help of bearings. These are components of bridge
that enables even distribution of load on the substructure material.
This transmission is very essential in situations where the substructure
is not designed to take the load action directly.
The
bearings in bridges allows the longitudinal movement of the girders.
This movement is created due to the forces acting on the longitudinal
direction. The forces due to the moving loads and the variation in
temperature are the main causes for longitudinal forces.
The
selection of bearing is dependent on certain parameters, which are:
Loads acting, the geometry, the extent of maintenance, the clearance
available, the displacement, rotation and deflection policy,
availability, preference of the designer, the construction tolerances,
and the cost criteria.
For the bridge design, all the
above-mentioned aspect is considered for the design and the choice of
bearings. The designer must consider the bearing arrangement in the
bridge construction as a separate system.
In most of construction
practice, the bearing is selected or the decision for bearing is done in
the last moment. This results in increase of maintenance in the future,
which must be avoided.
Substructure Components of Bridges
The components involved in substructure of bridges are:
Piers
Abutments
Wing Walls and the Returns
Foundation
Piers
The
piers are vertical structures used to support deck or the bearings
provided for load transmission to underground soil through foundation.
These structures serve as supports for the bridge spans at intermediate
points.
The pier structure has mainly two functions:
Load transmission to the Foundation
Resistance to the horizontal forces
Most
of the cases, piers are designed to resist the vertical loads alone. In
areas which lie in the seismic zone, it is recommended to design the
pier for lateral loads also.
Most
of the piers are constructed using concrete. Steel for the construction
of pier is used in very few cases till now. Use of composite columns
i.e. steel columns filled with concrete is used as new technology of
pier construction.
The pier is a vertical member that resist the
forces by means of shear mechanism. These forces are mainly lateral
forces. The pier that consist of multiple columns are called as bent.
Types of Piers in Bridge Construction
There are different types of piers based on the structural connectivity, the shape of the section and the framing configuration.
Based on the structural connectivity, the pier can be classified as monolithic or cantilevered.
Based on the shape of the section pier can be classified as solid or hollow, hexagonal, round or octagonal or rectangular.
Based on the framing configuration the pier can be classified as single or multiple column bent, hammerhead or pier wall type.
Abutments
Abutments
are vertical structures used to retain the earth behind the structure.
The dead and the live loads from the bridge superstructure is supported
by the bridge abutments.
The
abutments are also subjected to lateral pressures mainly from the
approach embankment. The design loads on the abutment is mainly
dependent on the:
Type of abutment selected
The sequence of construction
The figure below shows the primary functions carried out by an abutment.
Fig: Abutments in Bridge Construction- Primary Functions
As
seen from the above figure, the abutments have the design requirements
similar to retaining walls as well as in pier construction. The
abutments are primarily designed to resists the overturning and sliding.
More focus is on the stability of the whole system.
The special
care has to be provided for the foundations of abutments. The abutment
foundation must overcome the problems of differential settlement and
excessive movements caused due to lateral forces or loads.
The below figure shows the components of abutments.
Fig: Abutments Components
Wing Walls and Returns
Structures
constructed as an extension of the abutments to retain the earth
present in the approach bank are called wing walls. This portion will
otherwise have a natural angle of repose. These are retaining walls
constructed adjacent to the abutments. This wall can be constructed
either integrally or independent with the abutment wall.
The rear of the wall must consider three design loads while designing. This includes:
The earth pressure from the backfill
The surcharge from the live loads or the compacting plant
The hydraulic loads from the saturated soil conditions
The
stability of the wing wall is mainly based on its resistance against
the active earth pressures. The structural elements of the bridges are
hereby designed and constructed to resist the earth pressures at rest.
Parapets and Handrails/ Guard Rails or Curbs
These
components of bridges are not of structural importance, but provided
for the safety concerns. These are provided above the decks. This will
help in prevention of the vehicle from falling off the bridge into the
water body below or as a means for the separation of traffic streams.
Foundation of Bridges
Foundation
are structures constructed to transmit the load from the piers,
abutments, wing walls and the returns evenly on the strata.
The
foundation provided for bridge structures are deep in sufficient manner
to avoid scouring due to the water movement or to reduce the chances of
undermining.
Pier: A pier is a raised structure that sits in a
body of water to support a bridge. The open structure of a pier allows
water to pass through it, preventing pressure from building up against
it.
Pile:A pile is a vertical support
structure that’s used, in part, to hold up a bridge. It can be made
of wood, concrete, or steel. A pile is hammered into the soil beneath
the bridge until the end of it reaches the hard sub layer of compacted
soil or rock below. Piles hammered to this depth leverage the grip and
friction of the soil surrounding it to support part of the load of the
bridge deck.
Side plate: A side plate is a linear bearing that is
used as a part of an expansion joint of a bridge. One plate is
typically fixed, and the other slides over it to accommodate expansion
and contraction. This provides the bridge structure with support while
accommodating shifts in temperature.
Skew arch: A skew (sometimes referred to as an
oblique arch) is a style of arch where its faces are not perpendicular
to the abutments of the bridge. The interior of the arch takes the form
of a parallelogram, rather than a rectangle or square. Using a skew arch
allows a bridge to cross a span at virtually any angle, rather than
just a straight line.
Superstructure: The superstructure is the part of
the bridge that absorbs the live load. (The abutment, piers, and other
support elements are referred to as the substructure.)
