3. المعلقة للجسور اإلنشائي السلوك(Structural Behavior:)
اإلنشائي التحليل(Structural Analysis:)
شد اجهادات شكل على الجسر بالطة على المطبقة الحموالت من تجعل الجسور من النوع هذا تشكيل طريقة إن
الكابالت ضمن(الشاقوليةواالفقية)ضغط واجهاداتاألبراج ضمن(Pillars.)
in the cablestensionin a suspension bridge of any type areforcesThe main
in the pillars.compressionand
Since almost all the force on the pillars is vertically downwards and they are also
Severncan be made quite slender, as on thepillarsstabilized by the main cables, the
England border.-, on the WalesBridge
فالوزن .. ًاسابق ذكرنا كما يتم الحموالت انتقالللبالطة الذاتيالحية وحموالتها(سياراتوعربات)تنتقل
قوى شكل على الشاقولية للكابالت.شدًاأيض شد قوى يولد مما األفقية الكابالت سهم زيادة في تساهم القوى هذه
.ضمنها
المساند إلى تنتقل الكابالت في المتشكلة االجهادات(أيإلى)األبراجشا ضغط قوى ًةمولدقوليًا(غالبيكون
الوسطية األبراج في محوريمركزي والاألبراج فيالطرفية.)بدورها واألبراجاألساسات إلى الحموالت تنقل
إلى ومنهااالجهادات هذه تحمل على قادرة تكون أن يجب التي التأسيس تربة.الهائلة
4. الر األفقية الكابالت في سهم سيتشكل الحموالت تطبيق عندئيسيةالكابل وسيكونقطع شكل على المشوهناقص
(Parabola)منحني شكل ذات تكون محملة الغير الكابالت أن االعتبار بعين األخذ معألسباب وذلكفنية
واقتصاديةوانشائية.
الشكل ويوضحانكلترا بين الواقع سيفرن جسر في المتشكل السهم السابقوويلز.
In a suspended deck bridge, cables suspended via towers hold up the road deck. The
transferred by the cables to the towers, which in turn transfer the weight toweight is
the ground.
vehiclesAssuming a negligible weight as compared to the weight of the deck and
(veryparabolabeing supported, the main cables of a suspension bridge will form a
form the unloaded cables take before the deck is added)., thecatenarysimilar to a
One can see the shape from the constant increase of the gradient of the cable with
linear (deck) distance, this increase in gradient at each connection with the deck
rce. Combined with the relatively simpleproviding a net upward support fo
constraints placed upon the actual deck, this makes the suspension bridge much
, where the deck is in compression.cableasimpler to design and analyze than
مزاياالجسورالمعلقة(Advantages):
أنواع من آخر نوع أي من أكثر كبيرة مجازات تحقيق.الجسور
المواد من أقل كميات تتطلب حيث االنشاء في االقتصاديةأقل ومقاطعالجسور من األخرى األنواع من
قدرتها من التقليل دونعلى.التحمل
تنفيذ امكانيةالجسر وانشاءالجسر أسفل الموجودة الطرق أو المائية الممرات على التأثير دونويستثنى
منالمؤقتة الكابالت تركيب عملية ذلك.الرئيسية
تعرضها أثناء مسموحة بسيطة لحركة إمكانية تمنحها الجسور هذه مرونةألحمالمن يزيد مما الزالزل
تح قدرةقوى عن ناتجة النزياحات تتعرض عندما تنكسر قد التي الصلبة الجسور عكس على ملها.أفقية
7. ( المعلقة الجسور تشييد عمليةConstruction Sequence: )
و الجسر طول على العملية هذه تعتمد و .. التالية الخطوات وفق المعلقة الجسور تشييد مراحل تقسيم يمكن
عا بين تتراوح مدة عادة تستغرق و أبعادهعامين أو مإلنهائهابعض في أعوام عشرة إلى المدة هذه تصل قد و ..
.. الحاالت
Typical suspension bridges are constructed using a sequence generally described as
follows. Depending on length and size, construction may take anywhere between a
year and a half (construction on the original Tacoma Narrows Bridge took only 19
months) to as many as a decade (the Akashi-Kaikyō Bridge's construction began in
May 1986 and was opened in May, 1998 – a total of twelve years).
1. Where the towers are founded on underwater piers, caissons are sunk and any
soft bottom is excavated for a foundation. If thebedrock is too deep to be
exposed by excavation or the sinking of a caisson, pilings are driven to the
bedrock or into overlying hard soil, or a large concrete pad to distribute the
weight over less resistant soil may be constructed, first preparing the surface
with a bed of compacted gravel. (Such a pad footing can also accommodate
the movements of an active fault, and this has been implemented on the
foundations of the cable-stayed Rio-Antirio bridge. The piers are then
extended above water level, where they are capped with pedestal bases for
the towers.
2. Where the towers are founded on dry land, deep foundation excavation or
pilings are used.
3. From the tower foundation, towers of single or multiple columns are erected
using high-strength reinforced concrete, stonework, or steel. Concrete is used
most frequently in modern suspension bridge construction due to the high
cost of steel.
4. Large devices called saddles, which will carry the main suspension cables, are
positioned atop the towers. Typically of cast steel, they can also be
manufactured using riveted forms, and are equipped with rollers to allow the
main cables to shift under construction and normal loads.
5. Anchorages are constructed, usually in tandem with the towers, to resist the
tension of the cables and form as the main anchor system for the entire
structure. These are usually anchored in good quality rock, but may consist of
massive reinforced concrete deadweights within an excavation. The anchorage
8. structure will have multiple protruding open eyebolts enclosed within a secure
space.
6. Temporary suspended walkways, called catwalks, are then erected using a set
of guide wires hoisted into place via winches positioned atop the towers.
These catwalks follow the curve set by bridge designers for the main cables, in
a path mathematically described as a catenary arc. Typical catwalks are usually
between eight and ten feet wide, and are constructed using wire grate and
wood slats.
7. Gantries are placed upon the catwalks, which will support the main cable
spinning reels. Then, cables attached to winches are installed, and in turn, the
main cable spinning devices are installed.
8. High strength wire (typically 4 or 6 gauge galvanized steel wire), is pulled in a
loop by pulleys on the traveler, with one end affixed at an anchorage. When
the traveler reaches the opposite anchorage the loop is placed over an open
anchor eyebar. Along the catwalk, workers also pull the cable wires to their
desired tension. This continues until a bundle, called a "cable strand" is
completed, and temporarily bundled using stainless steel wire. This process is
repeated until the final cable strand is completed. Workers then remove the
individual wraps on the cable strands (during the spinning process, the shape
of the main cable closely resembles a hexagon), and then the entire cable is
then compressed by a traveling hydraulic press into a closely packed cylinder
and tightly wrapped with additional wire to form the final circular cross
section. The wire used in suspension bridge construction is a galvanized steel
wire that has been coated with corrosion inhibitors.
9. At specific points along the main cable (each being the exact distance
horizontally in relation to the next) devices called "cable bands" are installed
to carry steel wire ropes called Suspender cables. Each suspender cable is
engineered and cut to precise lengths, and are looped over the cable bands. In
some bridges, where the towers are close to or on the shore, the suspender
cables may be applied only to the central span. Early suspender cables were
fitted with zinc jewels and a set of steel washers, which formed the support
for the deck. Modern suspender cables carry a shackle-type fitting.
10.Special lifting hoists attached to the suspenders or from the main cables are
used to lift prefabricated sections of bridge deck to the proper level, provided
that the local conditions allow the sections to be carried below the bridge by
barge or other means. Otherwise, a traveling cantilever derrick may be used to
9. extend the deck one section at a time starting from the towers and working
outward. If the addition of the deck structure extends from the towers the
finished portions of the deck will pitch upward rather sharply, as there is no
downward force in the center of the span. Upon completion of the deck the
added load will pull the main cables into an arc mathematically described as
a parabola, while the arc of the deck will be as the designer intended – usually
a gentle upward arc for added clearance if over a shipping channel, or flat in
other cases such as a span over a canyon. Arched suspension spans also give
the structure more rigidity and strength.
11.With completion of the primary structure various details such as lighting,
handrails, finish painting and paving are installed or completed.
المالبحث لهذا المستخدمة راجع(References):
1. "Port Authority of New York and New Jersey - George Washington Bridge". The
Port Authority of New York and New Jersey. Retrieved 13 September 2013.
2. Bod Woodruff, Lana Zak, and Stephanie Wash (20 November 2012). "GW
Bridge Painters: Dangerous Job on Top of the World's Busiest Bridge". ABC
News. Retrieved 13 September 2013.
3. Chakzampa Thangtong Gyalpo – Architect, Philosopher and Iron Chain Bridge
Builder by Manfred Gerner. Thimphu: Center for Bhutan Studies 2007. ISBN
99936-14-39-4
4. Lhasa and Its Mysteries by Lawrence Austine Waddell, 1905, p.313
5. Bhutan. Lonely Planet. 2007. ISBN 978-1-74059-529-2.
6. "Chakzampa Thangtong Gyalpo". Centre for Bhutan Studies. p. 61.
7. "Iron Wire of the Wheeling Suspension Bridge". Smithsonian Museum
Conservation Institute.
8. November 2001. ISBN 978-0-7603-1234-6.
9. Peters, Tom F. (1987). Transitions in Engineering: Guillaume Henri Dufour and
the Early 19th Century Cable Suspension Bridges. Birkhauser. ISBN 3-7643-
1929-1.
10. Cleveland Bridge Company (UK) Web site Retrieved 21 February 2007,
includes image of the bridge.
11. McGloin, Bernard. "Symphonies in Steel: Bay Bridge and the Golden Gate".
Virtual Museum of the City of San Francisco. Retrieved 12 January 2008.
12. المستقرة الكابالت جسور أشهر منالعالم حول:
Centennial Bridgewith aPanama Canallane vehicular bridge that crosses the-, a six
ft).km (3,451of 1.05total length
Basarab Overpassstayed bridge in-) is the widest cableRomania(Bucharestin
Europe, measuring 44,5 meters in width and accommodating a two way tram station
its widestwith full platforms, safety areas and two traffic lanes in each direction at
point.
Cable Bridgestayed bridge in the United States, crosses-, the second cable
.Kennewick, WashingtontoPasco, Washingtonand connectslumbia RiverCothe
Vasco da Gama Bridge, Portugal is the longest bridge in Europe, with a totalLisbonin
kmmi) for the main bridge, 11.5km (0.5mi), including 0.829km (10.7length of 17.2
mi) in extension roads.km (3.0mi) in viaducts, and 4.8(7.1
Zhivopisny Bridgestayed bridge in Europe.-is the highest cablein Moscow, Russia,
( البحث هذا في المستخدمة المراجعReferences: )
1. "Bluff Dale Suspension Bridge". Historic American Engineering Record. Library
of Congress.
2. "Barton Creek Bridge". Historic American Engineering Record. Library of
Congress.
3. Jump up to:a b
Troyano, Leonardo (2003). Bridge Engineering: A Global
Perspective. Thomas Telford. pp. 650–652. ISBN 0-7277-3215-3.
4. Virlogeux, Michel (2001-02-01). "Bridges with multiple cable-stayed
spans". Structural Engineering International 11 (1): 61–
82. doi:10.2749/101686601780324250. Retrieved 2008-03-08.
5. "Bridging To The Future Of Engineering" (Press release). American Society of
Civil Engineers. 2007-03-12. Retrieved 2008-03-08.
6. http://www.hotnews.ro/stiri-esential-8935712-multimedia-vezi-cum-arata-
pasajul-basarab-inaugurare.htm
7. "Lyne Bridge, Chertsey - Railway Structures". Southern E-Group. Retrieved 30
August 2013.
13. الكابالتالمعدنيةفيالجسورالمعلقة(Cables: )
أحد عن عبارة هي عام بشكل الكابالتتستخدم الجسور في و المواد من العديد من تتكون التي الحبال أنواع
.. المعدنية الكابالت
الماضي فيشاعال استخدام( الحديد من المصنوعة كابالتwrought Ironالتشييد و العلوم تطور مع لكن و )
الفوال الكابالت فظهرت أفضل نتائج يعطي الحديد مع الكربون من نسبة خلط أن وجد( ذيةSteelتجمع التي )
. الكربون قساوة و الحديد مرونة بين
في الحموالت لنقل استخدامها عن عدا .. االستخدامات من الكثير و األشكال من الكثير المعدنية للكابالت
.. الوظائف من الكثير تحقيق بهدف المباني من كثير في نشاهدها فقد المعلقة الجسور
دور هو منها يهمنا ما و. المعلقة للجسور االنشائية الجملة ضمن شد إلجهادات معرض انشائي كعنصر ها
( الكابالت تصنيعCables Construction: )
Wires
Steel wires for wire ropes are normally made of non-alloy carbon steel with a carbon
content of 0.4 to 0.95%. The tensile forces and to run over sheaves with relatively
small diameters.
Strands
In the so-called cross lay strands, the wires of the different layers cross each other. In
the mostly used parallel lay strands, the lay length of all the wire layers is equal and
the wires of any two superimposed layers are parallel, resulting in linear contact. The
wire of the outer layer is supported by two wires of the inner layer. These wires are
neighbours along the whole length of the strand. Parallel lay strands are made in one
operation. The endurance of wire ropes with this kind of strand is always much
greater than of those (seldom used) with cross lay strands. Parallel lay strands with
two wire layers have the construction Filler, Seale or Warrington.
Spiral ropes
In principle, spiral ropes are round strands as they have an assembly of layers of
wires laid helically over a centre with at least one layer of wires being laid in the
opposite direction to that of the outer layer. Spiral ropes can be dimensioned in such
a way that they are non-rotating which means that under tension the rope torque is
nearly zero. The open spiral rope consists only of round wires. The half-locked coil
rope and the full-locked coil rope always have a centre made of round wires. The
locked coil ropes have one or more outer layers of profile wires. They have the
advantage that their construction prevents the penetration of dirt and water to a
14. greater extent and it also protects them from loss of lubricant. In addition, they have
one further very important advantage as the ends of a broken outer wire cannot
leave the rope if it has the proper dimensions.
Stranded ropes
Stranded ropes are an assembly of several strands laid helically in one or more layers
around a core. This core can be one of three types. The first is a fiber core, made up
of synthetic material. Fiber cores are the most flexible and elastic, but have the
downside of getting crushed easily. The second type, wire strand core, is made up of
one additional strand of wire, and is typically used for suspension. The third type is
independent wire rope core, which is the most durable in all types of
environments. Most types of stranded ropes only have one strand layer over the core
(fibre core or steel core). The lay direction of the strands in the rope can be right
(symbol Z) or left (symbol S) and the lay direction of the wires can be right (symbol z)
or left (symbol s). This kind of rope is called ordinary lay rope if the lay direction of
the wires in the outer strands is in the opposite direction to the lay of the outer
strands themselves. If both the wires in the outer strands and the outer strands
themselves have the same lay direction, the rope is called a lang lay rope (formerly
Albert’s lay or Lang’s lay). Multi-strand ropes are all more or less resistant to rotation
and have at least two layers of strands laid helically around a centre. The direction of
the outer strands is opposite to that of the underlying strand layers. Ropes with three
strand layers can be nearly non-rotating. Ropes with two strand layers are mostly
only low-rotating
Left-hand ordinary lay (LHOL) wire rope (close-up). Right-hand lay strands are laid
into a left-hand lay rope.
15. Right-hand Lang's lay (RHLL) wire rope (close-up). Right-hand lay strands are laid into
a right-hand lay rope.
الكابالت ربط(Terminations):
الوقت نفس في الصعبة و ًاجد الهامة المسائل من بها المتصل العنصر إلى تثبيتها و الكابالت نهايات ربط يعتبر
عل سلبي بشكل سيؤثر الوصل عملية في خلل أي ألنمن يتمكن لن و المنشأ سينهار بالتالي و الحموالت انتقال ى
.. ًالطوي الصمود
الحبل إلى بربطها نقوم حلقة لتشكيل الكابل أو الحبل نهاية بثني نقوم أن هي ًااستخدام الربط وسائل أكثر من و
: التالي الشكل في كما ) حبسات ( معدنية تجهيزات طريق عن نحميها و نفسه
of a wire rope tends to fray readily, and cannot be easily connected to plantThe end
and equipment. There are different ways of securing the ends of wire ropes to
prevent fraying. The most common and useful type of end fitting for a wire rope is to
ack to form a loop. The loose end is then fixed back on the wire rope.turn the end b
الحموالت تكون حيث المعلقة للجسور بالنسبة أما .. متوسطة أو صغيرة قوى تحمل بإمكانها السابقة الوصلة
.. المطبقة الحمولة حجم مع يتناسب بما الوصالت تدعيم و تحسين من البد هائلة
الشكل يوضح واألفقي الرئيسي الكابل مع الشاقولي الكابل اتصال نقطة عند السابقة الوصلة تدعيم كيفية التالي
: المعلقة الجسور في
17. البحث هذا في المستخدمة المراجع(References:)
1. "Wilhelm Albert". Encyclopædia Britannica. Retrieved 9 April 2014.
2. Koetsier,Teun ; Ceccarelli, Marc (2012). "Explorations in the History of
Machines and Mechanisms". Springer Publishing. p. 388. Retrieved 9 April
2014.
3. Donald Sayenga. "Modern History of Wire Rope". History of the Atlantic Cable
& Submarine Telegraphy (atlantic-cable.com). Retrieved 9 April 2014.
4. Modern History of Wire Rope - Donald Sayenga
5. Iron: An illustrated weekly journal for iron and steel, Volume 63 by Sholto
Percy
6. The Mechanical Transmission of Power: Endless Rope Drives by Kris De
Decker, March 27, 2013
7. Hunter, Louis C.; Bryant, Lynwood (1991). A History of Industrial Power in the
United States, 1730-1930, Vol. 3: The Transmission of Power. Cambridge,
Massachusetts, London: MIT Press. ISBN 0-262-08198-9.
8. "Wire Rope Safety Training". Falck Productions. Retrieved 27 June 2012.
9. http://bzwxw.com/soft/UploadSoft/new4/ISO--17893-
2004.pdf%7Ctitle=Steel Wire Ropes - Vocabulary, designation, and
classification
10. Avallone, Eugene; Baumesiter III, Theodore (1978). Marks' Standard
Handbook for Mechanical Engineers (Ninth ed.). pp. 10–34. ISBN 0-07-004127-
X.
11. Feyrer, K.: Wire Ropes, Tension, Endurance, Reliability. Springer Berlin,
Heidelberg, New York 2007. ISBN 3-540-33821-7
12. S9086-UU-STM-010/CH-603R3 NAVAL SHIPS’ TECHNICAL MANUAL, CHAPTER
613, WIRE AND FIBER ROPE AND RIGGING http://www.fas.org/man/dod-
101/sys/ship/nstm/ch613.pdf
13. Primer of Towing / George H. Reid - 3rd ed. Fig. 3-5 p30 - Cornell Maritime
Pres
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