jueves, 3 de mayo de 2012

INTRODUCTION



INTRODUCTION

In the course of this portfolio by civil engineering students of fifth semester we aim toinvestigate the different concepts and engineering fields, looking for a complete workwhere the research was an important element to help achieve good performance and the same, the aim of this work is to an important space for everyone where we can clarify, enrich and seek solutions to many unknowns as students and engineers will arise in the course of our lives, most important is to study the different branches as future engineerscan choose to contribute to the progress of our country without having clear whether this is the way forward in our lives.

The various issues mentioned below as engineers seek to become conscious in order to achieve good management of our water resources and construction of structures such asbridges, roads, tunnels, hydraulic structures and steel structures, etc.. Since it is thesethat help us to maintain the welfare of the community and achieve goals that as engineerswe aim to achieve. It is worth mentioning that civil engineering is one of the most complete and interesting careers as it encompasses different specialties that are alwayspresent in the search for a better life providing us with different opportunities.

miércoles, 2 de mayo de 2012

HYDRAULIC ENGINEERING


HYDRAULIC ENGINEERING:

Hydraulic engineering as a sub-discipline of civil engineering is concerned with the flow and conveyance of fluids, principally water and sewage. One feature of these systems is the extensive use of gravity as the motive force to cause the movement of the fluids. This area of civil engineering is intimately related to the design of bridges, dams, channels, canals, and levees, and to both sanitary and environmental engineering.


Hydraulic engineering is the application of fluid mechanics principles to problems dealing with the collection, storage, control, transport, regulation, measurement, and use of water. Before beginning a hydraulic engineering project, one must figure out how much water is involved. The hydraulic engineer is concerned with the transport of sediment by the river, the interaction of the water with its alluvial boundary, and the occurrence of scour and deposition. "The hydraulic engineer actually develops conceptual designs for the various features which interact with water such as spillways and outlet works for dams, culverts for highways, canals and related structures for irrigation projects, and cooling-water facilities for thermal power plants.”



 HYDRAULIC STRUCTURES

The general mechanic is based in fluid of mechanic and big topics that covering water, canals and bridges. The fluid mechanic is based in three fundaments aspect:

Static: in the static is possible fundament aspect.
Kinematics: in the kinematics of the flow lines and trajectories
Dynamics: In the dynamics studies the forces which price water movement.


GENERAL HYDRAULICS

The hydraulics structures are necessary to achieve the use of resources water and control it is destructive action. Also they are built for the benefit of man and the development of making.

At is creating to benefits sectors which are:

Hydropower
Water transport
Improving water
Water supply for human consumption Flood control



Application



Common topics of design for hydraulic engineers include hydraulic structures such as dams, levees, water distribution networks, water collection networks, sewage collection networks, storm water management, sediment transport, and various other topics related to transportation engineering and geotechnical engineering. Equations developed from the principles of fluid dynamics and fluid mechanics are widely utilized by other engineering disciplines such as mechanical, aeronautical and even traffic engineers.

Related branches include hydrology and rheology while related applications include hydraulic modeling, flood mapping, catchment flood management plans, shoreline management plans, estuarine strategies, coastal protection, and flood alleviation.



HYDRAULIC ENGINEERING IN THE CENTER OF PETEN (GUATEMALA):

The great advances that left the Mayan tribes in terms of hydraulic engineering have a very broad field, they helped build irrigation systems for agriculture, canals and large walls that helped protect the great wars, and these breakthroughs are today helping thousands of people in Guatemala, to help communication, transportation and consumption of drinking water.




TEACHING OF HYDRAULIC ENGINEERING IN CUBA (1900-1942)

Article in which we study the evolution of the teaching of hydraulic engineering in Cuba between 1900 and 1942 in three stages of this period, through the analysis of the subjects incorporated in the curriculum of the engineering electrical, agricultural engineering, but mainly in civil engineering.





This video is about the different work as construction of hydraulic engineering in case easy as:
Pipes, sewers, etc.





TOPICS OF INTEREST


FLUID MECHANICS

Fluid mechanics is the study of fluids and the forces on them. (Fluids include liquids, gases, and plasmas.) Fluid mechanics can be divided into fluid statics, the study of fluids at rest; fluid kinematics, the study of fluids in motion; and fluid dynamics, the study of the effect of forces on fluid motion. It is a branch of continum mechanics, a subject which models matter without using the information that it is made out of atoms, that is, it models matter from a macroscopic viewpoint rather than from a microscopic viewpoint. Fluid mechanics, especially fluid dynamics, is an active field of research with many unsolved or partly solved problems.




 ASPECTS OF THE FLUID MECHANICS

THE SIZE: For flow of fluid within pipes, the pipe diameter is a characteristic length.

SPEED: The speed of an object is the magnitude of its velocity (the rate of change of its position); it is a scalar quantity.



PRESSURE: Pressure (the symbol: p) is the force per unit area applied in a direction perpendicular to the surface of an object.


HISTORY OF FLUID MECHANICS

This discipline was born with the emergence of agriculture in the early civilizations, which involved the creation of irrigation systems and canals and the accumulation of the first body of knowledge on water and would enhance a boom in shipping.

  • Archimides: Great Roman waterworks.
  • Leonardo Da Vinci: Turn to rethink the study of streams.
  • Toricelli and Pascal: Explosion primitive Fluid Mechanics.
  • Newton: Laws of the dynamics of fluids which subsequently broaden Bernoulli, Euler, Lagrange, Cauchy and the rest of the great minds of classicla mechanics.
  • Navier-Stokes: tensor calculus and the Navier-Stokes equations, let us establish the traditional hydraulic problems: pipes, channels, etc,
  • Reynolds: He analyzed the turbulent flow and got the number that bears his name, laying most of the conventions in this field. Meanwhile, broke throughdimensional analysis, which would emphasize Rayleigh, froude and others.
  • Doppler, Rayleigh and Mach: Analysis of the gases and sunds. 



martes, 1 de mayo de 2012

STEEL BUILDINGS



STEEL BUILDINGS

GENERAL ASPECTS
Steel is utilized by engineers in several buildings; they are utilizing the strength of steel to create some of the most resistant avant-garde designed buildings of the twenty-first century. Steel is strong enough to create large constructions without the need of internal supports; yet, it is also malleable, making it possible to create almost any building out of steel and metal components.



HISTORY
In the Middle Ages iron elements were used in the aisles of the cathedrals. The metal was used more frequently in the industrial revolution replacing wooden structures. There are two famous works of metal in the nineteenth century: The first is the Crystal Palace and the second is eiffel tower.

ADVANTAGES IN STEEL

STRUCTURES


·       Smaller columns
·       Large clear spans
·       Seismic performance
·       Design—Flexible
·       Reduced construction financing costs
·       Simple modification and renovation
·       Reduced construction time
·       Complete recyclability


DISVANTAGES IN STEEL STRUCTURES


·       Fireproof treatment
·       Corrosion

FAMOUS STEEL STRUCTURES

·       EIFFEL TOWER

·       THE CRYSTAL PALACE


lunes, 30 de abril de 2012

BRIDGES



BRIDGES:

A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle. Designs of bridges vary depending on the function of the bridge, the nature of the terrain where the bridge is constructed, the material used to make it and the funds available to build it.

TYPES OF BRIDGES

BEAM BRIDGES
The beam bridges are horizontal beams supported at each end by abutments, hence their structural name of simply supported. When there is more than one span the intermediate supports are known as piers. The earliest beam bridges were simple logs that sat across streams and similar simple structures. In modern times, beam bridges are large box steel girder bridges.



CANTILEVER BRIDGES
Cantilever Bridges are built using cantilevers horizontal beams supported on only one end. Most cantilever bridges use a pair of continuous spans that extend from opposite sides of the supporting piers to meet at the center of the obstacle the bridge crosses.



ARCH BRIDGES
Arch bridges have abutments at each end. The weight of the bridge is thrust into the abutments at either side. The earliest known arch bridges were built by the Greeks, and include the Arkadiko Bridge.



SUSPENSION BRIDGES
Suspension bridges are suspended from cables. The earliest suspension bridges were made of ropes or vines covered with pieces of bamboo. In modern bridges, the cables hang from towers that are attached to caissons or cofferdams.


MOVABLE BRIDGES
Movable bridges are designed to move out of the way of boats or other kinds of traffic, which would otherwise be too tall to fit. These are generally electrically powered.


TACOMA NARROWS:


The Tacoma Narrows Bridge is a pair of twin suspension bridges in the U.S. state of Washington, which carry State Route 16 (known as Primary State Highway 14 until 1964) across the Tacoma Narrows strait of Puget Sound between Tacoma and the Kitsap Peninsula. Historically, the name "Tacoma Narrows Bridge" has applied to the original bridge nicknamed "Galloping Gertie" which opened in July 1940 but collapsed due to aero elastic flutter four months later, as well as the replacement of the original bridge which opened in 1950 and still stands today as the westbound lanes of the present-day twin bridge complex.



The first Tacoma Narrows Bridge opened to traffic on July 1, 1940. Its main span collapsed into the Tacoma Narrows four months later on November 7, 1940, at 11:00 AM (Pacific time) due to a physical phenomenon known as aero elastic flutter caused by a 42 miles per hour (68 km/h) wind. The bridge collapse had lasting effects on science and engineering. In many undergraduate physics texts the event is presented as an example of elementary forced resonance with the wind providing an external periodic frequency that matched the natural structural frequency (even though the real cause of the bridge's failure was aero elastic flutter. Another reason in why the bridge was destroyed 4 months later was due to not only aero elastic flutter, but its solid sides, not allowing wind to pass through the bridge's deck.


Tacoma bridge video

Tunnels


TUNNELS:

A tunnel is an underground passageway, completely enclosed except for openings for ingress and egress, commonly at each end.
A tunnel may be for foot or vehicular road traffic, for rail traffic, or for a canal. Some tunnels are aqueducts to supply water for consumption or for hydroelectric stations or are sewers. Other uses include routing power or telecommunication cables, some are to permit wildlife such as European badgers to cross highways. Secret tunnels have given entrance to or escape from an area, such as the Cu Chi Tunnels or the smuggling tunnels in the Gaza Strip which connect it to Egypt. Some tunnels are not for transport at all but rather, are fortifications, for example Mittelwerk and Cheyenne Mountain.
In the United Kingdom, a pedestrian tunnel or other underpass beneath a road is called an underpass subway. In the United States that term now means an underground rapid transit system.
The central part of a rapid transit network is usually built in tunnels. Rail station platforms may be connected by pedestrian tunnels or by foot bridges.




CONSTRUCTION:
Tunnels are dug in types of materials varying from soft clay to hard rock. The method of tunnel construction depends on such factors as the ground conditions, the ground water conditions, the length and diameter of the tunnel drive, the depth of the tunnel, the logistics of supporting the tunnel excavation, the final use and shape of the tunnel and appropriate risk management.
There are three basic types of tunnel construction in common use:
Cut and cover tunnels, constructed in a shallow trench and then covered over.
Bored tunnels, constructed in situ, without removing the ground above. They are usually of circular or horseshoe cross-section.
Immersed tube tunnels, sunk into a body of water and sit on, or are buried just under.



VARIANT TUNNEL TYPES

DOUBLE-DECK TUNNEL
Some tunnels are double-deck, for example the two major segments of the San Francisco – Oakland Bay Bridge (completed in 1936) are linked by a double-deck tunnel, the largest diameter bore tunnel in the world. At construction this was a combination bidirectional rail and truck pathway on the lower deck with automobiles above, now converted to one-way road vehicle traffic on each deck.



ARTIFICIAL TUNNELS:
Over-bridges can sometimes be built by covering a road or river or railway with brick or steel arches, and then leveling the surface with earth. In railway parlance, a surface-level track which has been built or covered over is normally called a covered way.
Snow sheds are a kind of artificial tunnel built to protect a railway from avalanches of snow. Similarly the Stanwell Park, New South Wales steel tunnel, on the South Coast railway line, protects the line from rockfalls.



HAZARDS:
Owing to the enclosed space of a tunnel, fires can have very serious effects on users. The main dangers are gas and smoke production, with low concentrations of carbon monoxide being highly toxic. Fires killed 11 people in the Gotthard tunnel fire of 2001 for example, all of the victims succumbing to smoke and gas inhalation.


THE LONGEST TUNNELS
·       The Delaware Aqueduct in New York USA is the longest tunnel, of any type, in the world at 137 km (85 mi). It is drilled through solid rock.
·       The Gotthard Base Tunnel will be the longest rail tunnel in the world at 57 km (35 mi). It will be totally completed in 2017.
·       The Seikan Tunnel in Japan is the longest undersea rail tunnel in the world at 53.9 km (33.5 mi), of which 23.3 km (14.5 mi) is under the sea.
·       The Channel Tunnel between France and the United Kingdom under the English Channel is the second-longest, with a total length of 50 km (31 mi), of which 39 km (24 mi) is under the sea.
·       The Lötschberg Base Tunnel opened in June 2007 in Switzerland was the longest land rail tunnel, with a total of 34.5 km (21.4 mi).
·       The Lærdal Tunnel in Norway from Lærdal to Aurland is the world's longest road tunnel, intended for cars and similar vehicles, at 24.5 km (15.2 mi).
·       The Zhongnanshan Tunnel in People's Republic of China opened in January 2007 is the world's second longest highway tunnel and the longest road tunnel in Asia, at 18 km (11 mi).
·        The longest canal tunnel is the Rove Tunnel in France, over 7.12 km (4.42 mi) long.