This is a research on the Kentucky dam, in the United States. It highlights the various aspects which were involved during its construction, highlighting the various elements regarding the labor which was used, the time, duration, culture, civilization and its location. The research also gives a synopsis of the construction methods which were used, coupled with the tools and equipment giving the various classifications and types of equipment that were used. In addition, the research also analyzes the probable scenarios regarding the alternative construction methods which can be used presently, analyzing the various elements in relation to durability and cost.
One of the greatest dams in the American history is the Kentucky dam. This is a hydroelectric dam that lies on river Tennessee, which was built mainly to improve on navigation and to reduce floods in the lower parts of Ohio and Mississippi rivers. It was a major project which was initiated during the reigns of Franklin Roosevelt. The dam joins to the Kentucky Lake, occupying about 160,000 acres of land, with a canal connecting the nearby lake, Lake Barkley
Location of Kentucky dam
Kentucky dam is located on river Tennessee and covers a size of about 2600M in length with a depth of around 70M. It is the longest dam every built on river Tennessee, generating about 224000 Kilowatts of electricity. The dam on the other hand covers about 2100 miles of shoreline, on 161000 acres of surface water. Its construction took six years, from 1938 to 1944 after the communities that were living in Tennessee lobbied the government to construct the dam (“Kentucky Dam Location”), after the displacement of communities and families that were living around the area by a devastating flood that hit the area in 1937. This prompted the U.S Corps to conduct a feasibility study, on how a dam could be built in order to reduce the effects that flooding brought to the communities.
Civilization and culture
In the western slope of the Appalachians, Native American Indians used to navigate through the Kentucky River across turbulent waters using unpowered boats and ships. They engaged themselves in trade, across the Kentucky River using flatboats to transport their goods to the market. In those times, the economic and social levels of the people lagged behind with most of them still being uncivilized, hence lacking the ability to envision the use of modern transport systems within the region. This was mainly brought about by the big separation between the people as a result of lack of interaction with the outside world (Evans 61), with most of the people being used to traditional ways of living where they depended mainly on hunting and traditional lifestyle such as grazing as a result of a rationalized level of modernity. However, as days went by, people envisioned modern ways of transporting goods to markets, methods of generating electricity as compared to other alternatives such as coal that was prevalent during those days.
Construction of the dam
Kentucky dam is the longest artificial manmade dam on river Tennessee. Its construction was overseen by the Tennessee Valley Authority (TVA), costing about $120 Million, mainly to control floods and to generate electricity. The dam’s powerhouse consists of turbine engines generators, producing electricity to the surrounding communities while also lessening the effects of floods by increasing navigation. The massive construction process involved many operations, with engineers and additional human labor, overseeing the dam’s construction process, which used a number of tools, materials, techniques, and methods.
There were various considerations which were made during the initial design and layout. These consisted of wind vibration, fatigue, and seismic considerations. The wind vibration element was considered during the construction of the steel trusses and the H-shaped bridges in which the center diagonals and the hangers were examined for dynamic wind oscillation properties. The fatigue elements were also examined on various diagonal joints to ascertain the possible fatigue stress so as to reduce structural fatigue on critical structures. On the other hand, given the location and proximity of the dam to the new Madrid fault zone, which predominantly experiences earthquakes, the design also considered seismic occurrences to reduce damage to the underground structures.
The first part of the dam construction process started with the resettlement process where the communities and families living in the area and along the river banks were relocated to other places to pave way for the construction of the dam. This was to create enough space where the dam and the reservoir would be located, and on the other hand create a loading zone for the earth moving and hauling equipment.
In addition to the resettlement process, the site that presently sits the dam and reservoir was cleared of vegetation and structures in order to give room for the initial construction process. The site clearance process consisted of various phases where vegetation was cleared. This consisted of grubbing, stripping and site scaling. The grubbing stage mainly involved the removal of stumps and roots, while the site stripping involved the removal of organic materials and soft pockets of soil which could not support strong structures.
In addition to this, other materials in the ground were removed and the surface leveled to form a uniform ground.
The initial construction process began with a massive design and construction of the Kentucky lake reservoir. This was done through the borrow pit excavation method where top decomposed soil was removed by the use of earth moving and hauling equipment. It was mainly done to dig up soil from the surface in order to create a stable foundation where a monolith and concrete pillars would be erected to support the structures of the dam.
After the soil excavation process had been completed, soil compaction was done on the excavated land. This was done through a pneumatic tired roller in order to increase soil compactness, thereafter a layer of concrete was added as filler. This was meant to support the side soils, in instances where they would collapse back into the already excavated land, as well as to prevent seepage failures that would compromise the strength of the dam. The concrete layer formed the foundation of the side walls in order to prevent muddy soil from curving back into the already excavated land. This was done to increase the stability and strength of the structures, including the massive bridge.
After the erection of filers, grouting was done on the excavated land. This is the process where a mixture of cement, water and rock particles were added into the foundation to make it impervious. This process involved the infilling of cracks on the base foundation so as to increase the structural strength of the dam, and also to prevent possible cracks.
In addition to this, an underground drainage tunnel was also designed at the base of the foundation. This was mainly to reduce ground water pressure which could occur as a result of pressure being exerted from the top.
Apart from the excavation, design and construction of fillers, as well as grouting, a critical feature on Kentucky dam was designed and constructed. This was a navigation lock, a critical feature which is used in enhancing navigation along the dam intersecting with the Tennessee River (“Work at Kentucky Dam lock hits milestone”).
A navigation lock is a dam system implemented in most dams to control the levels of water and to enhance navigation. These locks are approximately 14 in number along river Kentucky. In this instance, the locks are used to allow traffic to move along the river with the 1-4 locks being used for this purpose.
The Kentucky River locks were constructed in the factory. During the construction process, concrete was mixed with cement in order to create blocks of mixture of water and concrete, which were then placed into fabricated pieces of metal sheets. These metal sheets were joined together to form a long floating structure which was then transported using a barge back to the construction site. The locks were then placed along the channel on the dam.
There were also other attributes in the Kentucky dam construction. These are the turbine engines used for generating power along the Tennessee River, several electrical fitting and instrumentations currently used in the dam. The turbines engines are fitted at the dam’s power house, interfacing with the generator while connected to the power lines. They generate electricity when water from the reservoir enters through the inlet, rotating them thereby generating electricity.
While the locks function as expected, electronics plays an important role in maintaining the coordination of the various processes. This is mainly facilitated by a control room, which helps the employees of the Tennessee Valley Authority to monitor every instance of the dam. Whilst the various areas on Kentucky dam were designed and built, there are materials which helped to construct the structure of the dam. Some of these materials which were used included soil, gravel, rocks, concrete and others.
Materials used in the Kentucky dam construction
Fine-grained soil: Soil plays an important role in almost every dam construction. Soil was mainly used during the construction of Kentucky dam to lay a strong foundation. In this, compacted and compressed soil was added into the base after the excavation. This was mainly to remove air particles which could cause cracks to appear on the foundation.
Rock particles: Rock particles play an important role in almost all construction activities. The Kentucky dam was partly built using rock particles. In this instance, particles of rocks were filled and compacted on to harden the foundation. This was done mainly to increase the stability of the ground surface, by creating a level surface where grouting could be done.
Sand: Sand is used in almost every construction work. In this instance, sand was the mostly used material which was used in the construction of the dam. Sand was majorly used in the mixture of concrete to strengthen the mixture.
Water: Water is the main ingredient in construction works. This is because it is used to mix various construction materials. Water was used during the construction process to develop concrete, a mixture of sand, cement and gravel.
Cement: Cement was used in the construction of the Kentucky dam as a binder to hold together other materials such as sand, cement and ballast. This is because they were critical in the construction of the dam, such as binding the different materials together.
Concrete: Most parts of the Kentucky dam were constructed using concrete. This constituted the major elements of the constructed dam, including the foundation, sidewalls, fillers, pavements and the navigation locks. The foundation was constructed through concrete, where all pillars were erected as supporting structures. On the other hand, the sidewalls, fillers, pavements, and navigation lock were also constructed by the use of concrete. In this case, the navigation locks were built using concrete and fixed in given positions on the dam.
Steel: The Kentucky dam was heavily built using steel and other metals such as Iron. The first sections where steel was used were the pillars. Steel was used to construct pillars which have been used to support the entire structures, from the navigation locks, control room, engine turbines and motors. In addition to this, steel constitutes the major material which was used to build the major dam structures and drainage systems.
Iron sheets: Iron sheets were used almost everywhere during the construction of the dam. They were used in constructing the tunnels, drainage and other sections such as the roofing structure in the control room building.
Bricks: Bricks were used in many parts of the Kentucky dam construction. This includes the building of the sidewalls and pavements around the dam to reduce erosion and to strengthen the footpaths.
Ballast: Ballast constitutes the major dam construction material that was majorly used in the Kentucky dam construction process. Ballast was used to produce other materials such as concrete (mixture of water, sand and cement) which was meant for building the foundation and sidewalls of the dam.
In the initial stage of the Kentucky dam construction, a cofferdam was constructed (Jansen 222), mainly to help separate water from the land surface where the present dam sits on. In this instance, the structure was constructed to retain water in order for the construction engineers to pump water out of the enclosed area. The cofferdam was built mainly to allow the engineers to erect the steel piles which currently support the structure. During the construction of the cofferdam, the lower portion was constructed first by filling large rock particles into the cofferdam to increase the stability of the foundation. This was done through filling the excavated portion to a height of about 1200 feet, enough to carry large volume of water.
Tools and Equipment
During the construction of the Kentucky dam, there are several types of tools and equipment which were used. This equipment consisted of concrete production equipment, earth moving equipment, hauling, hoisting, conveying, dewatering, pile driving and rock drilling equipment.
Concrete production equipment
Batch plant: A batch plant is an equipment that is used to mix various ingredients that are used to produce concrete. This type of equipment was used during the Kentucky dam construction to mix water, sand, cement and ballast. In this instance, the materials would be fed into the batch plant using a tilt which would then mix all the ingredients to form concrete where the final element would be transported to the excavated site using a truck.
A silo is a bulk storage facility where large amounts of bags of cement are brought and stored. In this case, the silos were constructed next to the loading zone to enable trucks with cement bags to unload cement.
Earth moving equipment: These consisted of power shovel, back shovel, clam shell, bulldozer and a trenching machine. These were mainly used in the initial stages of the construction process. In this, the power shovel was used for excavation, where by land was excavated and loaded into tractors. In addition to this, the back and clam shovels were also used where the back shovel helped in grading works while the latter assisted in handling the crashed pieces of rocks and stones into standby trucks. Additionally, a bulldozer and a trenching machine were also used, where the bulldozer assisted in moving already excavated soil to other sections within the construction site, while the trencher helped in excavating lines which were used as conduit for electrical and other piping works, transporting electricity from the turbine to the control room. It also helped in the construction of outlets and inlets to control the inflow and outflow of water.
Earth compacting equipment: These mainly consisted of the smooth wheel roller and pneumatic tyred roller. The smooth wheel roller was used for light compaction during the construction of the foundation, while the pneumatic tyred roller was used in the construction of pavements and roads leading to the dam.
Hauling equipment: commonly known as haulers, these were used to transport items to and within the construction site. These consisted of tractors and dump trucks. Tractors were used to transport gravel, sand and soil as well as concrete to other areas within the location, while dump trucks were used to transport rocks during the grouting process.
Hoisting equipment: Hoisting involves the lifting of heavy materials from one location to the other. This equipment mainly consisted of the mobile, gantry and tower cranes. The mobile cranes were placed on different locations mainly to lift and carry items from one location to the other, while gantry cranes were used to fit heavy items such as the navigation locks into place across the river. In addition to these, the tower crane was used to move and place heavy steel structures in place.
Conveying equipment: This was used in the concrete production. In this instance, ballast, sand and cement were transported through a pulley into the batch plant.
Dewatering equipment: Mainly used to remove water from sections that needed to be worked on during the dam construction process.
Rock drilling equipment: Mainly used to drill rock surfaces during the construction of the foundation. In this area, the drill rigs and rock drills were used to drill out large particles of rocks which had protruded above the surface of the ground, and were complicating the soil leveling process.
However, the dam construction process also involved a massive labor force which was tasked with various responsibilities, among them construction engineers, drivers, electricians, mobile crane operators, scaffolders and welders, other than a large number of employees that handled manual work during the initial site clearance process.
Construction engineers: Professionals with different specialties, in metals, electricals, soil science and structural engineering. In the Kentucky dam construction project, metallurgists were tasked with analyzing the critical structural elements, such as of metals used for constructing the different structural entities, such as pillars for structural attributes such as stress, while electrical engineers helped in the wiring section in the control room and power transmission system. Besides this, there were soil elements that needed to be analyzed to ensure that the soil quality beneath can support the heavy structure.
However, with the acceleration of modern dam engineering techniques, there are modern dam construction methods which have evolved leading to the development of modern and alternative dam construction methods, some of which have helped in the design and construction of modern twenty-first century dams. According to an analysis within the engineering domain, certain modern dam construction methods such as the roller compacted and trapezoidal construction techniques need to be used in this modern age of technology. This is because engineering trends according to recent statistics indicate that such methods are world’s most advanced dam construction techniques, with a number of dams in the U.S and Japan having being built using this technology.
Roller compacted construction method:
This method could be used given the structural complexity which increases stability and strength of most dams. This is due to the layers of concrete which are spread on the foundation to increase compaction thereby strengthening the overall dam structure. The method also uses very cementitious mix of materials such as pozalan and other hydraulic based substances to increase the structural strength and resistance from corrosion as well as chemical attack, compared to other conventional dam construction techniques that mainly use additional layers of concrete.
Other than this, this method also extensively uses mineral additives and mixtures, such as fly ash, an important mineral that increases the durability of the dam. The RCC method also has low cement consumption compared with the conventional dam construction methods which are not only expensive, but consume time. Therefore, in this, the method would be more cost effective, durable and less time consuming which in this case would enable dam builders to construct more durable structures, with strong joints and water tightness in a shorter period of time compared to other conventional methods of dam construction.
Trapezoidal construction technique:
This is also a modern dam construction method of relative strength and durability. It is a construction method that encompasses modern engineering paradigms in material technology, design and construction technology. In the analysis of materials technology, the construction method is enhanced much more by readily available materials which are relatively easy to obtain thereby reducing costs associated with the construction process. In using this technology, the construction process is therefore likely to consume much little time, as well as the production of a stronger dam.
To understand its structural attributes, the trapezoidal construction method uses advanced construction designs with the ability to withstand high-level earthquakes, compared to the legacy methods such as the earth fill method used in the Kentucky dam. In this aspect, the method produces stronger dams which are also able to withstand high levels of stress, especially in an instance where there is a variation in loading, a principle in dam construction related to blasting and shaking (Jansen, 297).
In addition to this, the Kentucky dam would be built using the Trapezoidal construction method given the advancement in construction technology that it utilizes. This is because the technique utilizes the trapezoid kind of shape that increases stability hence making it be able to withstand seismic activities capable of weakening the structural elements. This also reduces instances of repair such as those that are currently experienced at Kentucky dam. Trapezoidal construction method can also be effectively used in the modern times. This is due to its efficiency in flood control and navigation enhancement, which are critical elements that are considered in modern dam construction techniques.
Given the advancements in construction technology, the Kentucky dam would be built either using the two methods, since we had very few modern dam construction technologies in 1938. However, with the advancement of information technology, it is very much possible to design, develop and construct modern dams with the ability to withstand calamities. In the past years during the construction of the Kentucky dam, advances in modern technology was low given the state of civilization during those times. There were no instances of interaction and communication, which also impacted on navigation in most lakes.
In conclusion, there have been advances in dam construction, with many construction methods coming into picture, giving rise to modern, durable and cost effective dams. Therefore, the Kentucky dam can be reconstructed to meet the international standards based on modern construction techniques.
Evans, Christopher T. South of the Mouth of Sandy. Bloomington, IN: AuthorHouse, 2007. Print.
Jansen, Robert B. Advanced Dam Engineering for Design, Construction, and Rehabilitation. Boston, MA: Springer US, 1989. Web.
Jansen, Robert B. Advanced Dam Engineering for Design, Construction, and Rehabilitation. Boston, MA: Springer US, 1989. Web.
“Kentucky Dam Location.” Kentucky Dam History. Web. 20 Nov. 2015. <https://www.explorekentuckylake.com/lakesarea/history/kydam.htm>.
“Work at Kentucky Dam Lock Hits Milestone.” Timesfreepress.com. Timesfreepress, 29 Jan. 2015. Web. 21 Nov. 2015. <http://www.timesfreepress.com/news/national/tennessee/story/2015/jan/29/work-kentucky-dam-lock-hits-milestone/285451/>.