Reinforced Slab Bridges used For short spans, a solid reinforced concrete slab, generally cast in-situ rather than precast, is the simplest design to about 25m span, such voided slabs are more economical than prestressed slabs.
Slab bridges are defined as structures where the deck slab also serves as the main load-carrying component. The span-to-width ratios are such that these bridges may be designed for simple 1-way bending as opposed to 2-way plate bending. This design guide provides a basic procedural outline for the design of slab bridges using the LRFD Code and also includes a worked example.
The LRFD design process for slab bridges is similar to the LFD design process. Both codes require the main reinforcement to be designed for Strength, Fatigue, Control of Cracking, and Limits of Reinforcement. All reinforcement shall be fully developed at the point of necessity. The minimum slab depth guidelines specified in Table 2.5.2.6.3-1 need not be followed if the reinforcement meets these requirements.
For design, the Approximate Elastic or “Strip” Method for slab bridges found in Article 4.6.2.3 shall be used. According to Article 9.7.1.4, edges of slabs shall either be strengthened or be supported by an edge beam which is integral with the slab. As depicted in Figure 3.2.11-1 of the Bridge Manual, the #5 d1 bars which extend from the 34 in. F-Shape barrier into the slab qualify as shear reinforcement (strengthening) for the outside edges of slabs.
When a 34 in. or 42 in. F-Shape barrier (with similar d1 bars) is used on a slab bridge, its structural adequacy as an edge beam should typically only need to be verified. The barrier should not be considered structural. Edge beam design is required for bridges with open joints and possibly at stage construction lines. If the out-to-out width of a slab bridge exceeds 45 ft., an open longitudinal joint is required.
Steel Connection is divided into two common methods: bolting and welding.
Bolting is the preferred method of Steel connecting members on the site. Staggered bolt layout allows easier access for tightening with a pneumatic wrench when a connection is all bolted. High strength bolts may be snug-tightened or slip-critical. Snug-tightened connections are referred to as bearing connections Bolts in a slip-critical connection act like clamps holding the plies of the material together.Bearing type connections may have threads included ( Type N ) or excluded ( Type X ) from the shear plane(s). Including the threads in the shear plane reduces the strength of the connection by approximately 25%. Loading along the length of the bolt puts the bolt in axial tension. If tension failure occurs, it usually takes place in the threaded section.Three types of high strength bolts A325, A490 (Hexagonal Head Bolts), and F1852 (Button Head Bolt). A325 may be galvanized A490 bolts must not be galvanized F1852 bolts are mechanically galvanized. High strength bolts are most commonly available in 5/8” – 1 ½” diameters. Bolting requires punching or drilling of holes. Holes may be standard size holes, oversize holes, short slotted holes, long slotted holes
Due to high costs of labor, extensive field -welding is the most expensive component in a steel frame. Welding should be performed on bare metal. Shop welding is preferred over field welding. The weld material should have a higher strength than the pieces being connected.Single-pass welds are more economical than multi-pass welds. The most economical size weld that may be horizontally deposited in one pass has 5/16”. Fillet welds and groove welds make up the majority of all structural welds. The strength of a fillet weld is directly proportional to the weld’s throat dimension. The capacity of a weld depends on the weld’s throat dimension and its length.
Contiguous Piled Wall With Ground Anchor Support Design Spreadsheet
Contiguous Piles, structures made of piles, and pile-like structures are useful structural elements to support deep excavations and cuts in slopes, and to retain creeping or sliding slopes, not uncommonly in seismic areas.
Depending on the static system and the dimensions the structural elements transfer forcesmainly by shear (“dowel”) and/or mainly by bending (“beam”) to the ground.
In numerous cases they are particularly effective in combination with otherstructural measures like (pre-stressed)
anchors and/or drainage systems. The paper presents case histories including piles and pile-like structures, which are applied for retaining structures in slopes.
The main focus is on infrastructureprojects in creeping slopes. Two case historiesfrom Austria and Sloveniaare presented in detail. Miscellaneous projects from European countries concentrating on various aspects complement
New Bridge Composite Twice as Strong as Concrete and Steel
The University of Maine’s Advanced Structures and Composites Center tests the strength of their new composite girders at a ceremony on July 12th. (Image courtesy of University of Maine.)
Researchers at the University of Maine have developed a lightweight composite bridge that is twice as strong as steel and concrete bridge girders.
In a mid-July demonstration, the university’s Advanced Structures and Composites Center tested a 21-foot span of the composite with computer-controlled hydraulic equipment that can simulate the weight of highway traffic. The test was necessary to ensure that the bridge passed American Association of State Highway and Transportation Officials (AASHTO) Bridge Design Specifications, and it succeeded with flying colours.
“Today’s bridge test exceeded our expectations,” said Habib Dagher, executive director of the Center. “The composite bridge withstood forces equivalent to more than 80 cars stacked on top of each other, and more than 5 times the HL 93 design load specified by AASHTO. The composite bridge girder exceeded twice the collapse strength of steel and concrete girders.”
The design is made up of lightweight composite FRP girders connected to precast concrete panels, a system which the team says can allow a bridge to be built in as little as three days. The composite is an undisclosed blend that involves thermoset resin, glass fiber and carbon fiber, which means that the girders are relatively light (approximately 1-2 tons for 40- to 80-foot spans). The lighter weight makes the bridge easier to ship, as does the “stackable” shape of the girders. To Dagher and his team, the ease of transport was an important consideration: “Our design philosophy has been to look at the entire lifecycle.”
The test came a little over a month after the US Department of Transportation announced that they would grant UMaine up to $14.2 million to lead a push to improve the durability of New England’s transportation infrastructure. And it looks like the bridge will stand up to the challenge. According to the team, the girders are designed to last for up to 100 years, and the panels are relatively easy to replace. “The unique connection system we’ve developed allows you to come in 50 years later, essentially pull the deck out and then put the new deck on without having to jackhammer the concrete deck like you typically would,” Dagher said.
The Center is also responsible for the famous Bridge-In-A-Backpack, a lightweight FRP composite structure to reinforce arch bridges. And Advanced Infrastructure Technologies, the company that licensed Bridge-in-a-Backpack, is looking forward to licencing the new composite after another round of trials in August.
“As the commercialization partner of the Center’s composite arch bridge system, today’s event allowed us to showcase this new technology with potential investors as well as DOT partners and executives,” said Brit Svoboda, chairman and CEO of AIT Bridges, on the day of the trial. “We’re ready to go to market.”
Water, one of the few natural resources without which there is no life, is distributed throughout the world unevenly in terms of place, season and quality. For this reason it is essential to construct dams on rivers, thus forming reservoirs for the storage and the even use of water.
To date, forty-two thousand large dams have been built worldwide, and hundreds of thousands of smaller ones, which have made possible a rational use of a certain amount of river water – the most important water resource for human life and activity. Dams, together with their appurtenant hydraulic structures, belong among the most complex engineering works, above all because of their interaction with the water, their great influence on the environment and their high cost.
Therefore great significance is given to theoretical research relating to dams, to improving the methods of analysing and constructing them, and to the knowledge gained in the course of their exploitation. In the past forty years great progress has been made in this respect.
Water plays an exceptionally significant role in the economy and in the life of all countries. It is of crucial importance to the existence of people, animals, and vegetation. The settling of people in different regions of the Earth has always been closely dependant on the possibilities for water supply, parallel with those for providing food, shelter, and heat.
The increase in population, as well as the development and enrichment of mankind, in a number of places has reached a level at which the water supply, needed for the population, industry, irrigation, and production of electric power, has been brought to a critical point.
On the other hand, reserves of water on Earth are very large. They have been estimated to amount to 1.45 billion km3 (Grishin et al., 1979). If we assume that the above quantity of water is uniformly spread over the Earth’s surface, then the thickness of such a water layer would be almost 3,000 m. As much as 90% of that quantity is attributable to the water of oceans and seas, while the remainder of barely 10% belongs to lakes, rivers, underground waters, and glaciers, as well as moisture from water in the atmosphere. Only 1/5 of the freshwater, which is suitable for man’s life and activities, is available for use.
More than twenty large dams and over a hundred smaller ones have been built in the Republic of Macedonia, which have still only partially exploited the available water, and flood control remains incomplete. The majority of the large dams were built in the period from 1952 to 1982 while, principally because of the lack of investment, the past twenty years have seen the construction mainly of smaller dams with a height of up to twenty metres and a reservoir volume of 300,000 cubic metres.
In the next few years some two or three more large dams will be completed which will still not
satisfy the need for water for the water supply, for irrigation and for the production of electrical energy, which are continually on the increase. The situation in all developing countries is similar, so that dams will continue to be built in the future despite the resistance on the part of devotees of the unobstructed flow of rivers.
An important unfavourable circumstance, which renders difficult a more complete utilization of water, is the fact that it is very not uniformly distributed on the Earth’s surface – considering space, time, and quality. That is to say, particular countries and regions suffer from drought, while others possess too large quantities of water. Also, the very same region could, in the course of a particular period of the year, be exposed to drought, while suffering from floods in another period. In that way, water, that common nationwide wealth without which no life is possible, can be an irreplaceable friend to man, but also his great enemy if he is not able to utilize it in a correct manner and to keep it under control.
Hydraulic land reclamation, i.e. irrigation of land, or else drainage of excess water from a specific territory. At the moment, irrigation systems cover approximately 270 × 106 ha, or 20% of the total cultivated areas. In many countries, especially in developing ones, increased food production is only possible by improving or increasing irrigation. The greatest amount of water is spent on irrigation – 3⁄4 of total consumption in the world. Great efforts are made to develop effective ways of saving water by avoiding losses in distribution networks and by applying more skillful irrigation techniques.
Dams can fail for one or a combination of the following reasons:
1. Overtopping caused by water spilling over the top of a dam. Overtopping of a dam is often a precursor of dam failure. National statistics show that overtopping due to inadequate spillway design, debris blockage of spillways, or settlement of the dam crest account for approximately 34% of all U.S. dam failures.
2. Foundation Defects, including settlement and slope instability, cause about 30% of all dam failures.
3. Cracking caused by movements like the natural settling of a dam.
4. Inadequate maintenance and upkeep.
5. Piping is when seepage through a dam is not properly filtered and soil particles continue to progress and form sink holes in the dam. [See an animation of a piping failure.] Another 20% of U.S. dam failures have been caused by piping (internal erosion caused by seepage). Seepage often occurs around hydraulic structures, such as pipes and spillways; through animal burrows; around roots of woody vegetation; and through cracks in dams, dam appurtenances, and dam foundations.
II. History of dam failures around the world
Here are some cases of dam failures around the world
1. Malpasset arch dam failure in France in 1959 (421 deaths)
The causes:
High uplift pressures following heavy rainfall & a weakness in the left abutment rock
Lessons learnt:
Appropriate SI and assessment by experts in all areas of dam design
2. Vaiont dam overtopping incident in Italy in 1963 (2600 deaths)
The causes:
Instability of reservoir slopes causing a landslip & 125m high wave over the dam
Lessons learnt:
Measure pore water pressures & movements at depth as well as at the surface
3. Dale Dyke dam breach in 1864 ( 244 deaths )
The causes:
Internal erosion possibly caused by hydraulic fracture of the core
Lessons learnt :
Designs include wider cores, use of cohesive & compacted fill and placing pipes in tunnels through natural ground
4. Eigiau & Coedty dam failures in 1925 (16 deaths)
The causes :
Foundation failure of Eigiau & overtopping failure of Coedty
Lessons learnt :
Dams need to be designed, supervised and inspected by qualified engineers
Slide Failure at Dam – Association of State Dam Safety Officials (ASDSO)
Cement is the basic ingredient of construction and the most widely used construction material. It is a very critical ingredient, because only cement has the ability of enhancing viscosity of concrete which in returns provides the better locking of sand and gravels together in a concrete mix.
CEMENT MANUFACTURING PROCESS PHASES
Production of cement completes after passing of raw materials from the following six phases. These are;
Raw material extraction/ Quarry
Grinding, Proportioning and Blending
Pre-heater Phase
Kiln Phase
Cooling and Final Grinding
Packing & Shipping
CEMENT MANUFACTURING PROCESS PHASE 1: RAW MATERIAL EXTRACTION
Cement uses raw materials that cover calcium, silicon, iron and aluminum. Such raw materials are limestone, clay and sand. Limestone is for calcium. It is combined with much smaller proportions of sand and clay. Sand & clay fulfill the need of silicon, iron and aluminum.
Extraction of raw material and crushing of material
Generally cement plants are fixed where the quarry of limestone is near bye. This saves the extra fuel cost and makes cement somehow economical. Raw materials are extracted from the quarry and by means of conveyor belt material is transported to the cement plant.
There are also various other raw materials used for cement manufacturing. For example shale, fly ash, mill scale and bauxite. These raw materials are directly brought from other sources because of small requirements.
Before transportation of raw materials to the cement plant, large size rocks are crushed into smaller size rocks with the help of crusher at quarry. Crusher reduces the size of large rocks to the size of gravels.
CEMENT MANUFACTURING PROCESS PHASE II: PROPORTIONING, BLENDING & GRINDING
The raw materials from quarry are now routed in plant laboratory where, they are analyzed and proper proportioning of limestone and clay are making possible before the beginning of grinding. Generally, limestone is 80% and remaining 20% is the clay.
Proportioning of raw material at cement plant laboratory
Now cement plant grind the raw mix with the help of heavy wheel type rollers and rotating table. Rotating table rotates continuously under the roller and brought the raw mix in contact with the roller. Roller crushes the material to a fine powder and finishes the job. Raw mix is stored in a pre-homogenization pile after grinding raw mix to fine powder.
CEMENT MANUFACTURING PROCESS PHASE III: PRE-HEATING RAW MATERIAL
After final grinding, the material is ready to face the pre-heating chamber. Pre-heater chamber consists of series of vertical cyclone from where the raw material passes before facing the kiln. Pre-heating chamber utilizes the emitting hot gases from kiln. Pre-heating of the material saves the energy and make plant environmental friendly.
Preheating of raw material | Vertical cyclone
CEMENT MANUFACTURING PROCESS PHASE IV: KILN PHASE
Kiln is a huge rotating furnace also called as the heart of cement making process. Here, raw material is heated up to 1450 ⁰C. This temperature begins a chemical reaction so called decarbonation. In this reaction material (like limestone) releases the carbon dioxide. High temperature of kiln makes slurry of the material.
Rotary kiln
The series of chemical reactions between calcium and silicon dioxide compounds form the primary constituents of cement i.e., calcium silicate. Kiln is heating up from the exit side by the use of natural gas and coal. When material reaches the lower part of the kiln, it forms the shape of clinker.
CEMENT MANUFACTURING PROCESS PHASE V: COOLING AND FINAL GRINDING
After passing out from the kiln, clinkers are cooled by mean of forced air. Clinker released the absorb heat and cool down to lower temperature. Released heat by clinker is reused by recirculating it back to the kiln. This too saves energy.
Clinker cooling | Cement making process
Final process of 5th phase is the final grinding. There is a horizontal filled with steel balls. Clinker reach in this rotating drum after cooling. Here, steel balls tumble and crush the clinker into a very fine powder. This fine powder is considered as cement. During grinding gypsum is also added to the mix in small percentage that controls the setting of cement.
Rotating ball mill
CEMENT MANUFACTURING PROCESS PHASE VI: PACKING AND SHIPPING
Transportation of cement from silos
Material is directly conveyed to the silos (silos are the large storage tanks of cement) from the grinding mills. Further, it is packed to about 20-40 kg bags. Only a small percent of cement is packed in the bags only for those customers whom need is very small. The remaining cement is shipped in bulk quantities by mean of trucks, rails or ships.
CEMENT MANUFACTURING PROCESS FLOW CHART
After explaining the complete process of cement making, flow chart would be like that. flow chart present the summary of whole process as shown below.
There are a lot of quotes related to civil engineering on the internet. We have gathered together all the inspirational, funny, motivating, interesting quotes related to civil engineering here. You will get all the best civil engineering quotes in the following list.
Inspirational Famous Civil Engineering Quotes
The followings are the inspirational quotes for civil engineers.
We shape our buildings, thereafter they shape us.
There can be little doubt that in many ways the story of bridge building is the story of civilisation. By it we can readily measure an important part of a people’s progress.
When engineers and quantity surveyors discuss aesthetics and architects study what cranes do we are on the right road.
This is not the age of pamphleteers. It is the age of engineers. The spark-gap is mightier than the pen. Democracy will not be salvaged by men who talk fluently, debate forcefully and quote aptly.
The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong, it usually turns out to be impossible to get at and repair.
The joy of engineering is to find a straight line on a double logarithmic diagram.
One has to watch out for engineers – they begin with the sewing machine and end up with the atomic bomb.
Nothing is so inspiring as seeing big works well laid out and planned and a real engineering organisation.
Nothing can be of great worth or holy which is the work of builders and mechanics.
No greater care is required upon any works than upon such as are to withstand the action of water; for this reason, all parts of the work need to be done exactly according to the rules of the art which all workmen know, but few observe.
Men build bridges and throw railroads across deserts, and yet they contend successfully that the job of sewing on a button is beyond them. Accordingly, they don’t have to sew buttons.
It takes an engineer to undertake the training of an engineer and not, as often happens, a theoretical engineer who is clever on a blackboard with mathematical formulae but useless as far as production is concerned.
His father loved him dearly, but his work, that of a civil engineer, had left him with but little time for his family. Energetic, active, and always taken up with some responsible work, he did not spoil his children with excessive tenderness.
Go for civil engineering, because civil engineering is the branch of engineering which teaches you the most about managing people. Managing people is a skill which is very, very useful and applies almost regardless of what you do.
From the laying out of a line of a tunnel to its final completion, the work may be either a series of experiments made at the expense of the proprietors of the project, or a series of judicious applications of the results of previous experience.
Engineers … are not mere technicians and should not approve or lend their name to any project that does not promise to be beneficent to man and the advancement of civilization
Engineering refers to the practice of organizing the design and construction [and, I would add operation] of any artifice which transforms the physical world around us to meet some recognized need.
Engineering is the art of modelling materials we do not wholly understand, into shapes we cannot precisely analyse so as to withstand forces we cannot properly assess, in such a way that the public has no reason to suspect the extent of our ignorance.
Architects and engineers are among the most fortunate of men since they build their own monuments with public consent, public approval and often public money.
A great bridge is a great monument which should serve to make known the splendour and genius of a nation; one should not occupy oneself with efforts to perfect it architecturally, for taste is always susceptible to change, but to conserve always in its form and decoration the character of solidity which is proper.
A good scientist is a person with original ideas. A good engineer is a person who makes a design that works with as few original ideas as possible
A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.
Scientists dream about doing great things. Engineers do them.
Scientists investigate that which already is; Engineers create that which has never been.
Each type of knowledge has value; however, from an engineering point of view, practical knowledge seems to be more valuable than theoretical knowledge.
Funny Civil Engineering Quotes
An engineer is someone who is good with figures, but doesn’t have the personality of an accountant.
Life is like a gas turbine, After every compressor, there is always a turbine!;
Engineering is the art and science of nuts and bolts.
Interesting Civil Engineering Quotes
“One man’s “magic” is another man’s engineering. “Supernatural” is a null word.”
In engineering, the joints are the most crucial. They have to be both firm and flexible, exactly like the joints in our body.;
Earlier this month, Russian President Vladimir Putin got behind the wheel of a bright orange dump truck and led a convoy across the Crimea Bridge, a new bridge that links Russia to the Crimean Peninsula. The bridge, which stretches12 miles across the Kerch Strait, is now Europe’s longest bridge.
But media coverage of the bridge hasn’t focused on its length, or any of its physical properties. That’s because the new bridge connects Russia to territory it annexed from the Ukraine in 2014—an action Western governments have called illegal. To many observers, especially those in the Ukraine, the bridge was a political power move, designed to seal Russia’s hold on the region.
While the politics of the bridge are complicated, its engineering is fascinating. A bridge across the Kerch Strait has been under consideration for more than a century, but has been blocked by brutal geological and environmental conditions. Experts in the area aren’t sure how long the bridge will stand.
History
The first Russian plans for the bridge were put forward by Tsar Nicholas II in 1903, but were then sidelined by wars and economic concerns soon afterward. German engineer Albert Speer picked up the idea for the bridge in 1943, envisioning that it would aid in the Nazi takeover of Soviet Russia. Bridge construction started that year, but was halted by Soviet attacks, and much of the remaining bridge was blown up by the German army during its retreat from the region.
The next year, the Soviet Army used the leftover building materials to build a single-track railway bridge across the strait for the wartime Yalta Conference. Part of the conference delegation managed to take the train across the bridge, but seasonal ice floes took out several of the structure’s supports in early 1945, and the bridge was not repaired. More permanent plans were put on hold due to the cost of the project and the difficult building conditions across the strait.
After the Soviet Union collapsed, politics became yet another barrier to bridge building. In 1954, Soviet Russia had transferred control of the Crimean Peninsula to Soviet Ukraine, so Russia no longer had control of Crimea when the USSR disbanded. Proposed projects in the 1990s and 2000s collapsed, but in 2010, the two countries finally signed an agreement to build a bridge together.
But Russia’s annexation of Crimea in 2014 severely strained relations between the two countries. The Ukraine imposed sanctions on Crimea, effectively cutting off most of its trade and forcing it to conduct trade across the strait with Russia by ferry. These sanctions made goods expensive in Crimea, as well as limited the number of Russia tourists crossing the strait to vacation there. So, in 2015, Putin announced that Russia would build a bridge to the peninsula on its own.
Building Bridges
In early 2015, the Russian government awarded the 228billion-ruble ($3.7 billion) bridge contract to infrastructure construction firm Stroygazmontazh Ltd. (SGM), a company that specialized in pipelines but which had not previously built any major bridges. The risk of international sanctions made it difficult to attract foreign investment or obtain insurance to cover the project, and SGM eventually used a small Crimean insurance company to underwrite a potential $3 billion loss.
The physical environment also presented several barriers to bridge construction. The site’s historic significance briefly worked against the project: divers searching the sea floor in preparation for the construction found over 200 bombs and a downed WWII-era plane. The weather also posed problems in the early stages of the project. Leonid Ryzhenkin, the project’s construction director, told NPR in 2016 that poor weather had interfered with the work, making it impossible for construction vessels to leave port. To limit weather disruption, SGM put up three temporary bridges to transport workers, supplies and heavy machinery like mobile cranes and piling rigs to the build sites.
Despite these disruptions, the project was finished ahead of schedule. And while officials projected that the road portion of the bridge would be finished by the end of 2018, it’s already open to light traffic.
The finished road bridge has four lanes, with a two-lane railroad bridge planned for the end of 2019. It stretches from the town of Taman in Russia to the city of Kerch on the Crimean Peninsula, passing through Tuzla Island along the way. It covers 4 miles of open water between Taman and Tuzla, 4 miles across the sandy island, and 3.4 more miles of water from Tuzla to Crimea.
Composite satellite image of the completed bridge, stretching from the Crimean Peninsula (left) to Russia’s Taman Peninsula (right). Approximately one-third of the bridge passes over Tuzla, an island that legally belongs to Crimea (Image courtesy of Google Maps.)
Between Tuzla and Crimea, there is a 745-foot double shipping channel arch, with one arch on the road bridge and one on the forthcoming rail bridge. Both arches have a 115-foot clearance for boats to pass underneath. The arches were built on land and towed out to sea by boat.
The road bridge is completed, and the rail bridge is on track to be finished soon. International disapproval hasn’t stopped the project’s construction—or even slowed it. But while the political and economic challenges facing the bridge have largely been overcome, there are other possible threats lurking under the waterline.
Shaky Ground
The Kerch Strait is known to be geologically unstable. A tectonic fault passes through the ocean floor under the strait, and the bedrock is covered in a layer of silt up to 197 feet thick that must be dug through to get a stable foundation. Further complicating matters is that the strait’s seismic activity can make mud volcanoes from the silt. Mud volcanoes are formed when water heated deep in the Earth’s crust mixes with underground mineral deposits, and the mixture is forced upward through a geological fault. As of 2010, Ukraine’s Department of Marine Geology and Sedimentary Ore Formation reported almost 70 mud volcanoes found in the Azov-Black Sea Basin where the Kerch Strait is located.
The bridge is supported by over 7,000 piles of three different varieties: bored piles (reinforced concrete piles poured into depressions on-site), prismatic piles (blunt, wedge-shaped supports), and tubular steel piles. These piles were driven up to 300 feet below water level because of concerns about stability.
The site’s tubular pillars are arranged in a fan shape, with many of the supports set at an angle, making the bridge more stable in case of seismic activity.
But not everyone thinks these measures will be enough to keep the bridge steady on its perilous ground. Civil engineer Georgy Rosnovsky, who previously designed two other possible versions of the Kerch Bridge, is troubled by the current design. He believes that the bridge is necessary, but has stated that he thinks it’s being built “in the wrong place and the wrong way.” He believes the pilings need to be at least 100 meters (328 feet) long, and worries that they are not sunk deep enough into the bedrock to be stable.
Rosnovsky also thinks that the bridge’s spans (the distance between supports) aren’t long to allow ice floes through. He planned his 1993 bridge with spans of 230-660 meters (755-2,170 feet), but said that any spans over 200 meters would be safe from ice. The current design’s longest span is 227 meters, but most of the spans are much shorter than that. According to Rosnovsky, this design puts the bridge at risk of suffering the same fate as the temporary bridge that was destroyed by ice floes in 1945.
Yuri Medovar, of the Russian Academy of Sciences, is another critic of the bridge. Talking to news agency Sotavision in late 2016, Medovar expressed concern that the area hadn’t been sufficiently mapped, and that the complex geology and weather conditions would make the structure risky. He warned of the costs of poorly built bridges, citing the 2013 bridge collapse in Borisoglebsk that killed two people. “You can build everything, ” he concluded, “but how much it will cost, and how [long will it] stand?”
Despite the difficult building conditions, the bridge’s creators aren’t worried about the possibility of collapse. “It will stay intact for 100 years, Rotenberg said in an interview with the Itogi Nedeli weekly news roundup after the bridge’s inaugural drive. “At least. We guarantee that. Everything is done perfectly well.” But critics like Rosenberg aren’t satisfied. “It’s a rich firm, but it’s not built by experts. They think that money is everything,” Rosnovsky told FOCUS in 2016. “The bridges are built from the calculation of the service life of a hundred years, but I think that this bridge will be short-lived.”
