Research






Aqueducts: Ancient Rome VS Modern society

posted 19 Aug 2013, 18:10 by Bryan Ong

Aqueduct

Firstly what is an Aqueduct?

An aqueduct is simply a Man-made channel or pipe that are made to transport water or fluid around a city or even a country


What are the many uses of aqueduct?

·         To transport water for agriculture purposes

·         To transport water over a large area of land

·         To transport dangerous fluids away quickly

So what kinds of Aqueducts are there?

From my research, there are mainly two types of aqueduct

They are the open air ducts and the pipes system. The open air ducts can be further classified into two more categories which are underground and supported.

 

 

Open Air Aqueducts are trenches or dug underground or supported by bridges for better transportation of fluids from reservoir or bodies of water.(maybe combined) They may come in many different forms from some as small as our local canal to some as large as 2km across as span a distance of hundreds and hundreds of km.

 

    

             

                                           

On the other hand, pipes are normally used where the fluid is required to be transported over a long distance of time or where open channels are substandard choices due to the fact that there may be evaporation, pollution or environmental impact. Some examples would be the transportation of distilled water or chemical waste from reactors. In which the pipes would be specially made and lined.

 

                                               

 

 

The structure difference in how they were build

Aqueduct from the past were lined with earth that was dig up from the nearby quarry or from the soil itself, thus a significant amount of water was lost through water seeping through the channel, as times past and technology improve, many have learn to line the ducts with concrete, polymers or soil that are impermeable. Furthermore, we have also learn to build additional channels beside the existing one should there be a need to improvise or constructed, the water transportation cycle would not be shut down.

 

 

Why was it important then?

Before the Aqueduct was invented, the people did not have a steady supply of water for their use, wells would sometimes be contaminated and rivers and quarries might dry up during the hot and dry season. By introducing the aqueducts into their daily life, they were able to get water when and when they wanted it even if they stay in rural areas with no access to clean water.

Furthermore the water flowed constantly. The water Starts flowing from an aqueduct into a fountain, from the fountain into a sewer. Thus resulting in a never ending system of clean water, which is relatively much safer than well water.

It’s also allowed access to foreign and far of water bodies should the population of the town be larger than what the local water source could supply.

 

 

What purposes does the aqueduct serve now?

It has a similar function to its predecessor which was to transport fluids. In the same scenario. A city or village might be too far off from a water supply or it is too densely populated for its own water source to support it thus the aqueduct is used to transport water from far-off area into it. An example would be from Malaysia to Singapore

 

Aqueducts from ROME

 

                        

Aqua Appia, the first ever Aqueduct to be build in Rome. It was build in 312 BC, which is a WHOPPING 2315 YEARS AGO!!!

The Aqua Appia flowed for 16.4 km into the city of Rome through the Port, and emptied into the Forum Boarium, near the Porta Trigeminal.

Nearly all of its length was underground, which was necessary because of the relative heights of its source and destination, and afforded it protection from attackers during the Samnite Wars that were underway during its construction.

However like many Olden aqueduct, it is no longer in use, but when it was operational, it transported over 75 000 000 litres of water into Rome every day. And till date, it is still considered as one of the most incredible engineering feat

 

 

          

 

Aqueduct of Segovia, the most significant and best-preserved ancient monuments left on the Iberian Peninsula. It is located in Spain and is the foremost symbol of Segovia, it was planned and constructed from 86AD to 92AD

The aqueduct transports waters from Fuente Fría River, situated in the nearby mountains, some 17 km (11 mi) from the city in a region known as La Acebeda. It runs another 15 km (9.3 mi) before arriving in the city.

The aqueduct is built of unmortared, brick-like granite blocks. During the Roman era, each of the three tallest arches displayed a sign in bronze letters, indicating the name of its builder along with the date of construction.

Today, two niches are still visible, one on each side of the aqueduct. One of them is known to have held the image of Hercules, who according to legend was founder of the city.

 

Modern day Aqueduct

 

 

                  

This is the Central Arizona Projects. A 336 mile long (541 km) diversion canal across Arizona in the United States. The aqueduct diverts water from the Colorado River from Lake Havasu City near Parker into central and southern Arizona. The CAP is the largest and most expensive aqueduct system ever constructed in the United States.

Arizona can use 100,000 acre feet (120,000,000 m3) of water per year starting in 2016. The CAP delivers Colorado River water, either directly or by exchange, into central and Southern Arizona.

The project was envisioned to provide water to nearly one million acres (405,000 hectares) of irrigated agricultural land areas in Maricopa, Pinal, and Pima counties, as well as municipal water for several Arizona communities, including the metropolitan areas of Phoenix and Tucson. 

 

The Colorado River duct

 

       

 is a 242 mi (389 km) water conveyance in Southern California in the United States, operated by the Metropolitan Water District of Southern California(MWD). The aqueduct impounds water from the Colorado River at Lake Havasu on the California-Arizona border west across the Mojave and Colorado deserts to the east side of the Santa Ana Mountains. It is one of the primary sources of drinking water for Southern California.

The system is composed of two reservoirs, five pumping stations, 63 mi (101 km) of canals, 92 mi (148 km) of tunnels, and 84 mi (135 km) of buried conduit and siphons. Average annual throughput is 1,200,000 acre·ft (1.5 km3).

 

Local Aqueducts

Many might not recognised foreign countries aqueducts but we have one right here in Singapore!!!

     

 

 

 

 

Singapore imports water from Johor state in Malaysia through a pipeline that runs along a 1 km bridge, the Johor–Singapore Causeway that also carries a road and a railway. As of 2009, imported water had been reduced from 50% previously to 40% of total consumption.

n 1927 the municipal commissioners of Singapore and Sultan Ibrahim of the state and territories of Johor in neighboring Malaya signed an agreement that allowed Singapore to rent land in Johor and use its water for free. In 1932 a pipeline to transport the raw water to Singapore was inaugurated. Another pipeline was built to return a smaller quantity of treated water to Johor.

 During the Battle of Singapore in 1942 the Causeway that links Singapore with Malaya and that carries the pipeline was blown up by retreating British troops, thus unintentionally destroying the pipeline, which left Singapore with water reserves that could last at most two weeks.

 

 


Hypocausts: Ancient Rome vs Modern Times

posted 19 Aug 2013, 00:16 by Benjamin Lim   [ updated 19 Aug 2013, 18:17 ]

What is hypocaust?

Rich Romans liked to be warm and cosy. They had central heating at home, in villas and in public baths. The heating system was kept going by slaves, who kept a fire blazing in a furnace to heat warm air. The warm air moved around the building through spaces under the floors and between the walls. The underfloor space was made by raising the floor on top of piles of tile or stone. The Roman heating system was called a hypocaust. 

The hypocaust is one of the most ancient forms of an HVAC system.  Like many great innovations, it originated with the Romans over 2000 years ago.  A hypocaust is both a primary system and a secondary system, as it creates heat and distributes it as well.

The main use for hypocausts was found in the large public bathhouses.  Sauna rooms were created by adding a pool of water, heated by the same fire heating the air below.  This created a hot, humid space to clean oneself and converse with friends.  The temperature could have easily reached 100 degrees Fahrenheit and the humidity could have reached 100% due to the pools.  These parameters are not exact, as the system has not been used is many, many years.


Its purpose was to evenly heat the room in the most efficient way possible.  A hypocaust was composed of a raised floor (typically about two feet), supported by columns or pedestals of stone every few feet, with the space below left open.  A furnace, composed of a continuously burning fire, created heat, which was then allowed to flow through the space below the raised floor, thus heating the floor and rest of the room.  Once cooled, the air escaped through flues in the wall and out of vents in the roof.  The furnace takes up a fair amount of space, so it was usually located in a separate room.  The flues were built directly into the walls so they did not take up useful space.

 

Connecting the aqueducts (which brought water into the city from the mountains), water tanks and pools were a series of tunnels.  These were constructed of brick and mortar (very crude for today’s standards, but they obviously worked

 

Like the water system, the air flow system was connected by ducts, consisting of stone or brick tunnels under the floor, into the large open space beneath the raised floor, and into the wall flues.  These flues also provided a source of insulation for the room.  The hot air rising created a barrier, keeping the warmth inside the building.

As mentioned above, the typical materials used in this system are stone, handmade brick and mortar.  An early form of concrete may also have been used, as the Roman had used it for many other buildings of the age (for example, the dome of the Pantheon).  Due to the second floor and pillars, this was difficult and laborious to construct.  Costs were much higher than a simple fireplace due to the larger amount of materials used.

 The main disadvantage of the hypocaust system is a very dangerous one.  The fumes created by the fire in the furnace easily crept out of the holding space below the false floor and into the main space.  This silent killer is now known as carbon monoxide.  Although it is easily detectable and preventable today, the Romans probably had no idea of this concept

 

Another disadvantage with this system is the possibility of the fire becoming unmanageable and getting out of control.  A stone or concrete building may survive, but the occupants may not.

 Needless to say, the hypocaust is no long used today.  However, we do have a modern version of this concept.  Radiant floor heating uses the basic concept to evenly heat the room, without the dangers of an open fire and fumes.  It is also much cheaper to do this system than a modern hypocaust.

 

 

 As an aside, the hypocaust is similar to a Korean Ondol.  It is basically set up in the same way, with sub-floor heating providing warmth for occupants.  This is also no long used, due to the same carbon monoxide and overheating problems.

 

Typical Uses

This system had a use in ancient times, but with today’s safety codes it is virtually impossible to use it in current time.  This is due to the fact that hypocaust systems have, in comparative terms, a high probability that the occupant will become ill or possibly die from carbon dioxide poisoning.  However, as a last resort to help struggling countries and villages, it might not be a bad idea to teach them to use these systems and maybe apply modern day synthetics or textiles to help avoid the danger (at least this is the only way we can see a modern day application for this system).

 

Parameters

 

Temperature ranges for a hypocaust system are not user controlled due to the fact that you can’t control the heat coming off of an open flame.  For this reason there are only two real settings for a hypocaust system; on and off.  This makes the low temperature that can be reached depend on the outside weather.  The maximum temperature that a hypocaust system can reach is about 100oF and humidity can reach about 100%.  The humidity can be added by heating pools of water.  Again there is not much control that this method provides.

 

General influences of romans

So many of the things we use every day have been influenced by the Romans – our calendar, domed buildings, highways, milestones, bridges, aqueducts, concrete, bronze valves, water pumps and more.  The Romans were excellent engineers, developing a large number of instruments and tools for engineering, construction and measurement.  But, when it comes to heating technology, we, in our industry, are most influenced by the architecture of the Roman baths – more specifically, their heating system - Although we do not use aquaducts today for our water source and our radiant heat technology has developed into a modern system, we use many of the same principles in our designs to attain comfortable, efficient heating.  Our course, we also enjoy some differences.  Today, we use water in our radiant systems, where the Romans used heat generated from their wood furnaces.  Also, our radiant floors have a lower temperature which creates the ultimate comfort.  We enjoy “toasty” feet and can enjoy the feel of the warm floors barefoot.  The Romans would have had to wear sandals to walk on the hottest floors because they had no way to regulate the temperature of the floor in the calderium. Romans invented aquaducts, which are now modern day water systems.

 

 

Modern underfloor heating systems

Modern underfloor heating systems use either electrical resistance elements ("electric systems") or fluid flowing in pipes ("hydronic systems") to heat the floor. Either type can be installed as the primary, whole-building heating system or as localized floor heating for thermal comfort. Electrical resistance can only be used for heating; when space cooling is also required, hydronic systems must be used. Other applications for which either electric or hydronic systems are suited include snow/ice melting for walks, driveways and landing pads, turf conditioning of football and soccer fields and frost prevention in freezers and skating rinks.

 

Electric heating elements or hydronic piping can be cast in a concrete floor slab ("poured floor system" or "wet system"). They can also be placed under the floor covering ("dry system") or attached directly to a wood sub floor ("sub floor system" or "dry system").

 

Some commercial buildings are designed to take advantage of thermal mass which is heated or cooled during off peak hours when utility rates are lower. With the heating/cooling system turned off during the day, the concrete mass and room temperature drift up or down within the desired comfort range. Such systems are known as thermally activated building systems or TABS.

 


Electric systems


 

Electric floor heating installation, cement being applied

Electric systems are used only for heating and employ non-corrosive, flexible heating elements including cables, pre-formed cable mats, bronze mesh, and carbon films. Due to their low profile they can be installed in a thermal mass or directly under floor finishes. Electric systems can also take advantage of time-of-use electricity metering and are frequently used as carpet heaters, portable under area rug heaters, under laminate floor heaters, under tile heating, under wood floor heating, and floor warming systems, including under shower floor and seat heating. Large electric systems also require skilled designers and tradespeople but this is less so for small floor warming systems. Electric systems use fewer components and are simpler to install and commission than hydronic systems. Some electric systems use line voltage technology while others use low voltage technology. Power consumption of an electric system is not based on voltage but rather wattage output produced by the heating element.

 

 

Typical under floor heating and cooling

 

 

Technical design

 

The amount of heat exchanged from or to an underfloor system is based on the combined radiant and convective heat transfer coefficients.

 Radiant heat transfer is constant

 Convective heat transfer changes over time depending on the air's density and thus its buoyancy. Air buoyancy changes according to surface temperatures and

 Forced air movement due to fans and the motion of people and objects in the space.

 

 

Convective heat transfer with underfloor systems is much greater when the system is operating in a heating rather than cooling mode. Typically with underfloor heating the convective component is almost 50% of the total heat transfer and in underfloor cooling the convective component is less than 10%.

 

Heat and moisture considerations

 

When heated and cooled pipes or heating cables share the same spaces as other building components, parasitic heat transfer can occur between refrigeration appliances, cold storage areas, domestic cold water lines, air conditioning and ventilation ducts. To control this, the pipes, cables and other building components must all be well insulated.

 

With underfloor cooling, condensation may collect on the surface of the floor. To prevent this, air humidity is kept low, below 50%, and floor temperatures are maintained above the dew point, 19 °C (66F)

 

Building systems and materials

 Heat losses to below grade The thermal conductivity of soil will influence the conductive heat transfer between the ground and heated or cooled slab-on-grade floors.

 Soils with moisture contents greater than 20% can be as much as 15 times more conductive than soils with less than 4% moisture content.

 Water tables and general soil conditions should be evaluated.

 Suitable under slab insulation such as rigid extruded or expanded polystyrene is required by Model National Energy Codes.

 

Heat losses at the exterior floor framing The heated or cooled sub-floor increases the temperature difference between the outdoors and the conditioned floor.

 The cavities created by the framing timbers such as headers, trimmers and cantilevered sections must then be insulated with rigid, batt or spray type insulations of suitable value based on climate and building techniques.

 

Masonry and other hard flooring considerations Concrete floors must accommodate shrinkage and expansion due to curing and changes in temperature.

 Curing times and temperatures for poured floors (concrete, lightweight toppings) must follow industry standards.

 Control and expansion joints and crack suppression techniques are required for all masonry type floors including;

·         Tile

·         Slate

·         Terrazzo

·         Stone

·         Marble

·         Concrete, stained, textured and stamped

 

 Wood flooring The dimensional stability of wood is based primary on moisture content, however, other factors can mitigate the changes to wood as it is heated or cooled, including; Wood species

·         Milling techniques, quarter sawn or plane sawn

·         Acclimation period

·         Relative humidity within the space

·         Piping standards

 

Using thermography to observe underfloor systems

 

 

Thermography is a useful tool to see the actual thermal efficacy of an underfloor system from its start up (as shown) to its operating conditions. In a startup it is easy to identify the tube location but less so as the system moves into a steady state condition. It is important to interpret thermographic images correctly. As is the case with finite element analysis (FEA), what is seen, reflects the conditions at the time of the image and may not represent the steady conditions. For example, the surfaces viewed in the images shown, may appear ‘hot’, but in reality are actually below the nominal temperature of the skin and core temperatures of the human body and the ability to ‘see’ the pipes does not equate to ‘feel’ the pipes. Thermography can also point out flaws in the building enclosures (left image, corner intersection detail), thermal bridging (right image, studs) and the heat losses associated with exterior doors

 

Credits:

http://www.tjsradiantheat.com/noteworthies/radiant-heat-then-and-now/

http://www.pages.drexel.edu/~jpm55/AE390/A5/hypocaust.htm

http://en.wikipedia.org/wiki/Hypocaust

https://www.google.com/search?q=hypocaust&safe=off&source=lnms&tbm=isch&sa=X&ei=Zr8SUqDcHoLtrAe6q4DIAw&ved=0CAkQ_AUoAQ&biw=1366&bih=667#facrc=_&imgdii=_&imgrc=dZn3f9IT62m6nM%3A%3BCb2kjt1Vx1W2MM%3Bhttp%253A%252F%252Fdepts.washington.edu%252Fhrome%252FAuthors%252Fkjw2%252FBathsBathinginAncientRome%252F243%252F244%252FHypocaustDiagram.jpg.1%3Bhttp%253A%252F%252Fdepts.washington.edu%252Fhrome%252FAuthors%252Fkjw2%252FBathsBathinginAncientRome%252Fpub_zbarticle_view_printable.html%3B1044%3B824


https://www.google.com/search?safe=off&biw=1366&bih=667&tbm=isch&sa=1&q=modern+under+floor+heating+systems&oq=modern+under+floor+heating+systems&gs_l=img.3...33651.42939.0.44060.36.31.1.4.4.0.317.1708.28j1j1j1.31.0....0...1c.1.25.img..21.15.631.KzqTxwjbvyE#facrc=_&imgdii=_&imgrc=1kZIlk4oZ6m2UM%3A%3Bx13vRLNVdiXsaM%3Bhttp%253A%252F%252Fwww.plumbwestheating.co.uk%252Fimages%252Fservices%252Funderfloor.jpg%3Bhttp%253A%252F%252Fwww.plumbwestheating.co.uk%252Funderfloor-heating.html%3B370%3B198


http://en.wikipedia.org/wiki/Underfloor_heating


Domes : Ancient Rome VS Modern Domes

posted 16 Aug 2013, 22:41 by Afiq Muslihin   [ updated 19 Aug 2013, 20:47 ]

Domes : Ancient Rome VS Modern Domes

Concept of Domes

Domes can be considered an arch which has been rotated around its central vertical axis. Hence, like arches, the structure of a dome can be sturdy when built proper and can span to large spaces without any interior support.

There are two structural types of domes
- Simple Domes
- Compound Domes

In a simple dome, the pendentives are a part of the structure of the dome. However, such structures are rarely found in the world. An example of a simple dome would be the Fantasy Entertainment Complex situated on the Kyosho Island, Japan.


Compound domes, unlike simple domes, are built around with the pendentives supporting the structure of the dome at the top.
Red signifies the dome. Yellow signifies the pendentives supporting the dome
 
An example of a compound dome would be The Dome of The Rock situated at Palestine.

General Types Of Domes

Onion domes, also known as Bulbous domes is a bulbous shape tapering smoothly to a point, strongly resembling an onion, after which they are named, and exemplified by Saint Basil's Cathedral in Moscow and the Taj Mahal. They are found mostly in eastern architecture, particularly in Russia, Turkey, India, and the Middle East.

The Taj Mahal (left) and Saint Basil's Cathedral(right)


A Corbel dome is different from a 'true dome' in that it consists of purely horizontal layers. As the layers get higher, each is slightly cantilevered, or corbeled, toward the center until meeting at the top. A famous example is the Mycenaean Treasury of Atreus.

A Geodesic dome is a spherical or partial-spherical shell structure or lattice shell based on a network of great circles (geodesics) on the surface of a sphere. The geodesics intersect to form triangular elements that have local triangular rigidity and also distribute the stress across the structure. When completed to form a complete sphere, it is a geodesic sphere. A dome is enclosed, unlike open geodesic structures such as playground climbers.
Spaceship Earth at Epcot, Walt Disney World, a geodesic sphere(left) and a simple geodesic playground(right)

An Oval dome comes in an oval shape in plan or profile or both. It comes from the term ovum, meaning "egg" in Latin. he earliest oval domes were used by convenience in corbelled stone huts as rounded but geometrically undefined coverings, and the first examples in Asia Minor date to around 4000 B.C. The geometry was eventually defined using combinations of circular arcs which transition at points of tangency. These domes tend to be circular unlike in a more ovular shape. An example of such dome is  Church of St. Gereon in Cologne, Rome.
Exterior and Interior of the Church of St. Gereon( Left and Right respectively )

A Parabolic dome is a unique structure, in which bending stress due to the Uniformly distributed load of its dead load is zero. It is widely used during the Ancient Times before the advent of composite structures. Unique in that the bending stress is zero (however) if a load is applied directly to the apex of the dome the stress becomes infinite (that so doesn’t sound good) so the tops of the dome had to be stiffened or its shape modified to avoid this potential engineering disaster.
Parabolic Dome, image by phileole

A Geodesic dome is a closed structure; a sphere made up of a Network of Circles lying on the surface of the sphere. (think soccer ball) The circles intersect forming triangular shapes that distributes the stress across the entire structure in an omni-triangulated manner. An example of a geodesic dome is the Montreal Biosphere located in Canada.


Polygonal domes are domes which maintain a Polygonal shape. Thomas Jefferson the 3rd U.S. President, installed one above the West front of his plantation house called Monticello.
Polygonal Dome on top of Thomas Jefferson's Monticello, image by wikimedia

Domes in Rome
 
The earliest domes were probably roofed primitive huts and consisted of bent-over branches plastered with mud. Another primitive form, called a beehive dome, is constructed of concentric rings of corbeled stones and has a conical shape. Ancient examples have been found in the tombs of Mycenae and can also still be seen in the folk architecture of Sicily. Although there is evidence of widespread knowledge of the dome, its early use was apparently restricted to small structures built of mud brick.


The Romans were the first to fully realise the architectural potentialities of the dome. The Roman development in dome construction culminated in The Pantheon constructed in 125 AD, which still stands as of today.
Pantheon and S. Teodoro
Pantheon(left) and San Tendoro(Right)


The Romans, however, failed to discover a proper handling of the pendentive and the device essential to placing a dome over a square compartment –that was finally achieved by the Byzantine builders of Hagia Sophia at Constantinople.
The Hagia Sopia, located at Constantinople.

The study and the actual building of various forms of domes became quite intense in the first half of the 15th century in northern Italy and in Tuscany, but not in Rome, where the authority of the Pope was challenged by the local factions. After so many centuries, the first dome, named San Tendoro designed by Bernardo Rossellino, was built in Rome.

Throughout time, the Roman Empire developed the domes to be designed for strength and protection. Aside from that, they made constructions of high rise domes possible by implementing the use of arches to form ceilings or roof, known as the vault, which compliments the structural integrity of the domes. 

Over time, further improvements were made by Byzantine builders to the structure of domes by placing a dome over a square was the squinch, which in the form of stalactites was to receive superb expression in Islamic architecture. Under Byzantine influence, the early Muslims adopted the use of the dome; one of their first important monuments is the Dome of the Rock in Jerusalem. They often used the so-called Persian or onion dome.
Modern Domes Around The World

During the Early Modern Period, including the renaissance, you can easily see that the dome shape was a popular element in architecture. One very well known structure of this time period is St. Peter's Basilica, which is located within the Vatican City in Rome. The dome in the middle of St. Peters Basilica was inspired by the circular Roman temple, the Pantheon.


Both the influence of the Roman Pantheon and of the Byzantine pendentive came to bear on the designers of the Italian Renaissance, and the crossings of many churches of the period were covered by masonry domes on pendentives. Between pendentive and dome a circular drum usually was interposed, serving to give greater elevation and external importance as well as a space for the introduction of windows. By the addition of an outer shell, the exterior came to be independently designed for maximum effectiveness, and the placing of a lantern at the top of this outer shell provided an apex for the entire composition.
Brunelleschi's Dome, built in 1436 and designed by Filippo Brunelleschi.

As the Post Modern Era came into being, sights were focused more on futuristic themes, and advances. Cities are filled with skyscrapers and industrial buildings; however, this future mindset brings forth a new type of use for domes. The domes in this time period are far more modern looking than any seen before and have a definite future-like essence. The Reliant Astrodome is nicknamed the "Eighth Wonder of the World" and is located in Houston, Texas. The Astrodome was completed in 1975, and is still used as a stadium. The dome has recently been home to many survivors of hurricane Katrina.

 "Eighth Wonder of the World", also known as The Reliant Astrodome

The dome in modern architecture utilizes such materials of construction as reinforced and thin-shell concrete, glass and steel, and plastic. An innovative contemporary approach to the form is the geodesic dome. These are low-cost, geometrically determined hemispherical forms as promoted by architect Buckminster Fuller.
Zeiss Optical Company's first geodesic dome, designed by the chief engineeer at Zeiss, Walter Bauersfeld.

Although the construction of domes have decreased significantly in the modern world, some are still constructed mainly for religious purposes or to for worldwide events.

Kallang
Singapore Sports hub, set to be completed in 2014.It has an upturning bowl-shaped dome, which includes a retractable roof.

The Flower Dome situated at Gardens By The Bay, Singapore, replicates the cool-dry climate of Mediterranean regions like South Africa, California and parts of Spain and Italy. Home to a collection of plants from deserts all over the world, it showcases the adaptations of plants to arid environments.

Conclusion

There is no doubt that the structural improvements and designs the Roman did generally to domes have inspired many architects to go further beyond their level. Till this day, domes bear a significance in both religion and important events happening around the world.

CREDITS

Arches: Arches of the Roman Empire vs Modern Arches of the World

posted 15 Aug 2013, 11:16 by Ameerul Hakim   [ updated 19 Aug 2013, 05:25 ]

Basic Concept of an Arch

  An Arch is basically a curved structure that is used to bridge an opening. It is able to support heavy load and forces that acts from above it. Arches can actually be arranged together as a set to form a vault, a structural group consisting of a set of arches, normally to form a roof or a ceiling. Vaults are commonly found in buildings that were erected during the Gothic period. Some famous examples of vaults are the corridors of Hogwarts Castle from Harry Potter and the vaulted ceilings of Westminster Abbey.

(The iconic castle used as Hogwarts from the Harry Potter series)

There are 3 basic types of arches: Circular, Pointed, and Parabolic.

CIRCULAR arch


  Also referred to as Rounded or round arches, this type of arch was commonly used in ancient society’s constructions, most of which were heavy masonry arches. One civilization that made use of circular arches was the Romans. They relied on these to span large and open areas for colossal projects like famous Colosseum (above).

POINTED arch

  One advantage of using this style of an arch, instead of the commonly used circular type, is that pointed arches produce less thrust at the base. Thrust basically is the force in the arch that is when carried to ground, the arch will push outwards to the base. Pointed arches were made use mostly through the Gothic period. This innovation allowed for taller and more closely spaced openings, a very typical form of Gothic architecture. Some famous structures that made use of the pointed arches were the Cathédrale Notre Dame de Paris (above) and the Taj Mahal.

PARABOLIC arch


  A parabolic arch utilizes the principle that if a weight is uniformly applied to an arch, the internal compression deriving from that weight will follow a parabolic profile. Among all the basic arch types, parabolic arches produce the most thrust at the base, but can span the largest areas. This type of arch is usually used in designs for bridges where long span is needed like between valleys or high areas. Some examples of a parabolic arch is The Arch of Saint Louis(above, left) and the Navajo Bridge(above, right) that spans the two sides of the humungous Grand Canyon.

STRENGTH of an arch

  Arch structures are so strong that some ancient ones are still standing strong today, most of which are either left in ruins, and very few still standing tall and functional. One example of how strong arches are, is the Ponte Vecchio (bottom).






Arches of the Roman Empire
(The Colisseum and Circus Maximus among other buildings of ancient Rome)

  Ancient Rome has achieved many great accomplishments that have influenced a number of cultures and other great societies then and now.  The Romans are famous for the majesty of their arches used in many buildings such as the colossal Colisseum and the Maximus Circus. Many are blinded by these magnificent and successful arches to think that the Romans were the ones who invented arches.

  Arches were used way before the Roman empire began to expand and thrive. Ancient Egyptians, Babylonians, and Greeks all used arches. However, these civilizations used arches limitedly to support small structures such as storerooms and tombs. People often used columns and pillars to support roofs and floors. Hence, builders could not construct extremely large palaces or government buildings.

 “The Romans were the first builders in Europe, perhaps the first in the world, fully to appreciate the advantages of the arch, the vault and the dome.” –D. S. Robertson (Greek and Roman Architecture)

 The Romans innovated these plainly used arches. The Roman arch made way for architects to explore different and a more larger structure for buildings. They combined arches to form ceilings or roofs known as vaults, and applies the principles of the arch to form a hemispherical ceiling or roof known as a dome. One known example of a Roman Dome is The Pantheon.

(Pont Du Gard, Segovia)

  The Roman’s use of arches and the improvements they’ve made in the usage of concrete and bricks assisted the erections of aqueducts throughout the Empire. The same concept was adopted to build bridges, some of which is still standing and used today. Art historian Gottfried Richter identified the Roman architectural innovation as being the Triumphal Arch, symbolizing power that was transformed and utilized within the Christian basilicas when the Western Roman Empire was coming to a fall. The arch is seen in aqueducts such as the Pont Du Gard in Segovia and what’s left of all the Aqueducts of Rome itself. The survival proves its durability of the materials and design.

(The remains of The Alconétar Bridge with its flattened arches)

  The Romans also then discovered that arches need not have to be semicircle. The Alconétar Bridge in Spain is one example of a Roman segmental arch bridge. It’s arches are only sectors of a circle that is lesser that of a semicircle.

(The Taj Mahal with its Majestic Arches)

  The Roman arch solved an important issue by being able to support large amounts of weight, enabling civil engineers to construct larger, more varied and majestic buildings. The spread of the Roman arch and its cousins, the vault and the dome, has a lasting impact on architecture throughout the world now and then. Without the Romans, there possibly wouldn’t be any Grandeur Cathedrals or the Taj Mahal, one of the Seven Wonders of the World.





Modern Arches of the World

(The iconic Sydney Harbour Bridge’s arch structure)

  After more than 2000 years, the arch continues to feature prominently in bridge designs. One good reason for this excessive usage is that the arch evenly distributes compression and force acting throughout its entire structure onto its two abutments, the component of the bridge that takes on the pressure directly, which is better known as the base of the arches.

  Modern arches make use of steel and pre-stressed concrete apart from masonries and stones, or the Special Roman Concrete, which was used in ancient times. Also, beams and trusses are used in modern arches, making the structure more rigid and able to span further than any arches from the ancient civilizations. A typical Modern arch span between 60 to 245 meters. However the Chaotianmen Bridge, the longest arch bridge at the moment, spans an impressive 552 meters!

SYDNEY HARBOUR BRIDGE

(The Sydney Harbour Bridge upon completion, 1931-1932)


  One iconic Arch Bridge is the Sydney Harbour Bridge. It is also one of the symbols of Australia and an example of a modern arch bridge. Also known as the ‘Coathanger’, the bridge was opened on the 19th of March 1932, after 6 years of construction. This bridge is like Australia’s version of New York’s Statue of Liberty.


(The arch of the Sydney Harbour Bridge being constructed, 1929-1930)

  The bridge has a span of about 503 meters, the 6th longest arch bridge currently. The Arch consists of two 28-paneled arch trusses. It spans about 500m. However, the steel structure expands on hot days, increasing the height of the arch from 134 meters to about 18 centimeters more. To accommodate the expansion and contraction, a resultant of the change in temperatures, large steel pins support each ends of the Arch at its bases. Thus, avoiding stresses that would otherwise cause a terrible damage on the iconic structure.

ANDERSON BRIDGE & ESPLANADE BRIDGE

(A view of the 2 arch bridges, Anderson Bridge and Esplanade Bridge, during the Singapore Grand Prix.)


  In the heart of Singapore, along the vibrant Singapore River, many bridges were built for convenience to connect the Civic District and the Central Business District. Two of the bridges along the river are arch bridges, both next to each other, both used to form part of the Singapore Grand Prix’s Marina Bay Circuit.

(A Formula 1 car driving out of the Anderson Bridge, which is part of the Marina Bay Circuit)

  The Anderson Bridge was intended to replace the Cavenagh Bridge that was overloaded with traffic then due to the flourishing trade on the Singapore River. The Bridge was opened in 1910 after 2 years of construction. The bridge is a truss arch bridge, which comprises a combination of intricate plaster and metalwork unmatched by any other bridge in Singapore then. Anderson Bridge comprises of 3 steel arches with supporting steel ribs across them.

(The Esplanade Bridge and its arches)

  The Esplanade Bridge was built mainly to assist traffic flow on the Anderson Bridge. The bridge serves as a faster way of access between both Marina Centre together with the Civic District, and the Central Business District. The bridge spans 260 meters across the mouth of the Singapore River. Completed after 3 years of construction, the bridge opened in 1997.

  Despite the opening of the larger and faster connection of Esplanade Bridge, the Anderson Bridge still functions as a vehicular bridge till today, and also an iconic part of the Formula One Singapore Street Circuit.

OTHER MODERN ARCH STRUCTURES

Other examples of modern arches includes:

The Sydney Opera House’s pointed arch roof structure (below)

 

The Gateshead Millenium Bridge in England(below, both). The only tilting bridge in the world, functions by tilting it’s pedestrian passage to let barges to pass through (below, right).


Conclusion

  Many of these magnificent clever forms of arch structures wouldn't be realised if the Romans weren't daring and adventurous enough to explore new ways to innovate the basic arches used by the Etruscans. The basic small span arches to build tombs or small roofs, limiting to small buildings. The ancient Romans however, were a clever and productive bunch of people. They managed to innovate the arch to build huge, grand, and long spanning structures like aqueducts and amphi-theatres. Ancient Rome has evolutionized civil engineering then, and influenced the modern civil engineers, which can be seen from examples of the modern day arch structure's architects that are also as daring enough as the ancient Romans to build it BIGGER, LONGER, and STRONGER!






Credits

Images

http://global.britannica.com/EBchecked/topic/32510/arch

http://0.tqn.com/d/gouk/1/0/b/s/-/-/677299.jpg

http://www.dudziak.com/pictures/europe_summer2007/rome/colosseum/ancient_roman_colosseum_1280.jpg

http://europeantrips.org/wp-content/uploads/2012/05/Notre-Dame-de-Paris.jpg

http://newdeserttimes.com/wp-content/uploads/2010/01/bigstockphoto_stlouis_arch_4869358.jpg

http://www.fhwa.dot.gov/eihd/images/navajo.jpg

 

http://www.florenceinferno.com/wp-content/uploads/2013/06/Ponte-Vecchio-Inferno.jpg

http://www.pontdugard.fr/sites/default/files/1_0.jpg

http://upload.wikimedia.org/wikipedia/commons/d/df/Puente_de_Alconétar,_Cáceres_Province,_Spain._Pic_08.jpg

http://upload.wikimedia.org/wikipedia/commons/c/c8/Taj_Mahal_in_March_2004.jpg

 

http://sydney-harbour-bridge.bos.nsw.edu.au/images-sepea/bridge5.jpg

http://upload.wikimedia.org/wikipedia/commons/f/fa/Early_construction%2C_Sydney_Harbour_Bridge.jpg

http://www.sydneyharbourbridge.info/img/bridge-old-1.jpg

http://farm7.staticflickr.com/6161/6162356835_d0f7e6b684_z.jpg

http://mercedesbenzblogphotodb.files.wordpress.com/2009/09/f1-singapore-2009-preview.jpg

http://upload.wikimedia.org/wikipedia/commons/f/ff/Esplanade_Bridge_2,_Dec_05.JPG

http://upload.wikimedia.org/wikipedia/commons/a/a1/Sydney_Opera_House_Night.jpg

http://blog.thistle.com/wp-content/uploads/2012/08/Gateshead-Millennium-Bridge.jpg

http://upload.wikimedia.org/wikipedia/commons/f/f8/Gateshead_Millennium_Bridge_-_coming_down.jpg

Basic Concept of an Arch

http://www.britannica.com/EBchecked/topic/32510/arch

http://www.britannica.com/EBchecked/topic/624158/vault

http://en.wikipedia.org/wiki/Arch

Arches of the Roman Empire

http://www.tribunesandtriumphs.org/roman-architecture/roman-arches.htm

http://www.eduplace.com/kids/socsci/ca/books/bkf3/writing/06_romarch.pdf

http://en.wikipedia.org/wiki/Ancient_Rome

http://books.google.com.sg/books?id=l3Ln6KMGio0C&pg=PA231&lpg=PA231&dq=The+Romans+were+the+first+builders+in+Europe,+perhaps+the+first+in+the+world,+fully+to+appreciate+the+advantages+of+the+arch,+the+vault+and+the+dome.&source=bl&ots=Iiwk3tt6b4&sig=ZsRxgS3q2w3bMDT7Uo3Zs9ouRKw&hl=en&sa=X&ei=An0LUvatNoiGkQW994GgBw&redir_esc=y#v=onepage&q&f=false

http://www.mariamilani.com/ancient_rome/rome_building_arches.htm

Modern Arches of the World

http://www.bristol.ac.uk/civilengineering/bridges/Pages/HowtoreadabridgeModernArches.html

http://science.howstuffworks.com/engineering/civil/bridge5.htm

http://en.wikipedia.org/wiki/List_of_the_largest_arch_bridges

http://www.sydneyharbourbridge.info

http://www.sydneyharbourbridge.com.au

http://en.wikipedia.org/wiki/Sydney_Harbour_Bridge

http://en.wikipedia.org/wiki/Anderson_Bridge

http://en.wikipedia.org/wiki/Esplanade_Bridge

http://www.gateshead.gov.uk/Leisure%20and%20Culture/attractions/bridge/Home.aspx/eurl.axd/38b15d78d8d23743ae79faaf23d024bf

Roads: Ancient Rome vs Modern Times

posted 15 Aug 2013, 08:32 by Benjamin Lim   [ updated 19 Aug 2013, 20:15 ]

Roads in Ancient Rome

Background information

  The roads of ancient Rome are one of the most durable remains of that ancient civilization. Roman roads were constructed to be immune to floods and other environmental hazards. A good road system ensured that letters and orders can be delivered faster. This boosted the emperor's control over the empire. They were certainly one of the most significant components of the mighty infrastructure and civil engineering capability which enabled the Roman Empire to flourish.

  Roman roads were crucial to the maintenance and development of the Roman state, and were built from about 500 BC. They provided efficient means for land movement of armies, officials and civilians, and the inland carriage of official communications and trade goods.  Roman roads were of several kinds, ranging from small local roads to broad, long-distance highways built to connect cities, major towns and military bases. These major roads were often stone-paved and metaled, arched for drainage, and were accompanied by footpaths, bridleways (horse riding trail) and drainage ditches. They were laid along accurately surveyed courses, and some were cut through hills, or over rivers and ravines (steep-sided valleys) on bridgework. Sections could be supported over marshy ground on rafted or piled foundations.

  At the peak of Rome's development, no fewer than 29 great military highways were erected from the capital, and the Late Empire's 113 provinces were interconnected by 372 great road links.  It comprised more than 400,000 km of roads, of which over 80,500 km were stone-paved. In Gaul alone, no less than 21,000 km of road are said to have been improved, and in Britain at least 4,000 km. The courses, and sometimes the surfaces of many Roman roads survived for millennia. Some are overlaid by modern roads.

Details:

Materials utilized

Pros

Cons

Debris

Cheap materials

Requires a long time

Sand

Materials easily sourced

No modern technology

Clay

Durable

Might be uneven

Stones (big and small)

 

 










4 types of roads

i. "Viae Publicae" - public roads built at public expense (taxpayer's money or war loot)

ii. "Viae Militares" - military roads, built by the army at their own expense but would eventually fall into the first category of public roads.

iii. "Actus" - minor roads, built and maintained by local councils

iv. "Privatae" - private roads built by private individuals at their own expense within their private property.

 

Laws and tradition

  The laws of the Twelve Tables, dated to approximately 450 BC, specified that a road shall be 8 ft (2.45 m) wide. These regulations were set by the Lex Julia Municipalis (45 BC) (Sets regulations for the Italian municipalities).

  The width of roads varied with the importance of the road: A width of 3m or over (9ft) was normal for roman roads to allow to carts to drive past each other in opposite directions although road widths as great as 7m (21ft) have been found. The edges of the road would be closed off by stones placed length ways, which in city centers would act as the step for pavements. In cities such as Pompeii and Osita the roads have been found to be a relatively consistent 4m (12ft) in width for major roads, with a further 4 meters worth of pavements i.e. 2m either side). Minor roads in the city were anywhere between 2 and 4m (6-12ft).

Big stones used on the road. Smaller stones at the side meant that it was for walking only


The main roads of Ancient Rome




Roads in modern times

Background information

  Asphalt is a heavy, dark brown to black mineral substance, one of several mixtures of hydrocarbons called bitumen. Bitumen is obtained through fractional distillation of crude oil. Bitumen is the heaviest amongst all the constituents.

Details:

Materials utilized

Pros

Cons

Asphalt

Smooth

Top layer wears out after long time

Sand

Construction is fast

Expensive

Cement

Better traction

 

Crushed rocks

Helps conserve car energy due to smoothness

 

 

Durable

 

 

Reduces noise pollution from vehicles

 

 

Types of roads

Highway, Expressways, Runways and car parks, etc., all use asphalt surfacing in modern day roads. 


 

Asphalt road being smoothened out


The Tarmac at Dubai International Airport



Conclusion

  In conclusion, the Romans played a huge role in road developments. The Romans certainly did inspire, as they were able to build such a vast system of roads and were able to manage it, without the use of modern technology. This has certainly led to our current state, a system of roads linking places. As the saying goes, All Roads Lead to Rome.



Credits


Ancient Rome:

http://en.wikipedia.org/wiki/Roman_engineering#Roads

http://en.wikipedia.org/wiki/Roman_roads

http://www.mariamilani.com/ancient_rome/rome_building_roads.htm

http://gizzisgoodies.wikispaces.com/file/view/lazio_roma-parco_dell-appia_antica.jpg/257210980/lazio_roma-parco_dell-appia_antica.jpg

http://travelingyourdream.com/wp-content/uploads/2012/11/roman-road.jpg

http://3.bp.blogspot.com/-w9_sbW-tDTs/TuujEW106nI/AAAAAAAAAw0/1KjmqnH4Cbs/s200/Roman-Roads-BAR700.jpg

http://www.historylearningsite.co.uk/roman_roads.htm

 

Modern roads:

http://asphaltroads.org/Environment

http://www.madehow.com/Volume-2/Asphalt-Cement.html

http://www.celsias.com/media/uploads/admin/roads_2.jpg

http://www.tropicalisland.de/united_arab_emirates/dubai/dubai_airport/images/DXB%20Dubai%20International%20Airport%20-%20tower%20with%20terminal%20building%20and%20tarmac%205340x3400.jpg

 

Conclusion

http://payload.cargocollective.com/1/2/86489/1166683/11.%20all%20roads%20lead%20to%20rome.jpg


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