Geotechnical Engineering And Physical Properties Engineering Essay

Geotechnical directing And Physical Properties Engineering EssayBurj Al Arab is the worlds tallest iconic and most lordly hotel. This edifice has received numerous recognitions around the world, and is mainly known by its design which resembles the shape of a sail boats mast.This 321 meter high make uping was built on a man-made island however 280 meters from the bound, big(p) all visitors a 360o view of the bay. Construction began in 1993. Engineers created a surface with a layer of rocks, which is circled with a honey-comb pattern which protects the surface and tooshie from erosion. The building contains more than 70000 m2 of cover and 9000 tons of steel. It took b arly two years to construct the building and three years to construct the unveiling on edge anchor, making this a geotechnical wonder.8IntroductionGeotechnical Engineering entails to obtain information of the physical properties of the territory and rock on a proposed site known as site exploration. This in formation combined with the mechanics of bemire digest assess the risks presented by the site conditions that must be concluded in the design process of foundations, earthworks and retaining walls.Burj Al Arab has one of the rarest and most interesting foundations, earthworks and retaining wall phenomenas. This include building an island 280 meter off coast as a foundation for this 321 meter high sea shore wonder.1 Through aside this report we will tactile sensation at which demesnes are found in Dubai, as come up as the properties thereof including the construction of this hotel foundation.Constructing the Burj Al Arab hotelThe design of the Burj Al Arab has been constructed with a specific geometry which supports the sail boat like design by protect the building from changing move loads. The outermost wall of the building has been constructed by the use of PTFE coated fiberglass which contains air gaps at regular intervals. This double curve membrane design is able to adj udge wind squelchs easily.3Additional cables charter been provided onto the structure to prevent any deflection in fabrics. On the full big top of the building expansion joints were provided on the right side of the building to ensure the building shadower withstand the wind load pressures as well as the horizontal stresses that may occur during construction and operation. The material that was used for this sail boat like structure is not only robust save it excessively protects the buildings interior from the sun by using light defusion.3After seventy thou common sense cubic meters of concrete and ninety thousand tons of steel, this great engineering wonder is noted as the heart of Dubai. This striking feature of the Burj Al Arabhotel, with its two hundred and two rooms, is rigid 280 meter off shore from the coast of Dubai and recognised as the best in the world. 2Concept Architect Tom Willis-WrightimagesCAHJ41BO.jpgConstruction Engineer WS Atkins and Partners Overseas M ultidisciplinary Consultancy.Interior designers Khuan Chew, Design Principal of KCA International (London).Location Jumeirah B individually Road, Jumeirah, Dubai, United Arab Emirates.Date 1994-1999 look PostmodernType/Structure Luxury 7 stars*rating hotel/resortSize 321m x 280m (1,053 ft) strength steel, glass, cement, steel cables, pilesFrom Antonino Terranova. The Great Skyscrapers of the World. Special gatefold edition, page 269-279.Figure 1 Burj Al Arab hotelDubais defect ProfileThe topography of Dubai (which lies within the Arabian Desert) is different from the southern portion of the UAE. Its landscape consists of sandy desert patterns consisting in general out of crushed shell and coral and is clean and white, whereas gravel dominates in the southern regions of the province. 2 When smell at the farming properties of Dubai, its weak and will most probably move outwards in the fibre of any construction on it. See figure 1 Dubai fault map. 3Studies as well render that Dubais possibility of a tsunami is minimal, due to the Persian Gulf irrigate that is not deep enough to evocation a tsunami. therefore Dubai is classified as a stable zone, whereas the nearest seismic fault overseas telegram is 120 km from the UAE, making it unlikely for Dubai to be hit by a seismic impact.2http//www.gis information.net/ minutes/mapmiddleeast/2006/natural%20resource%20management/images/mme06138_3.jpgFigure 2 Dubai primer coat map. human foot jobsThe moment when Dubai laid focus on the development of this world wonder, they knew it would be an engineering challenge. Many elements must be taken in consideration in geotechnical engineering to build the worlds 15th tallest building on seabed, where its properties are known as a folding(prenominal) skank due to a lack of silt and clay.The collapse phenomenon give the gate be defined as a soil which can withstand somewhat large stresses, with little stoppage at clinical depression in situ moisture content whic h will show signs of a decrease in volume and associated stop with no append of load if the moisture content rises. Therefore the change in volume goes return in hand with the change in the soil structure.It is thus evident that a number of conditions choose to be met before collapsing begins 6The soil must have a collapsible fabric in its structure. This is where the specified soil has a high vacant ratio and yet has relatively high fleece strength at low moisture content due to a coating (Colloidal) around each grain.Partial saturation is essential. This is where collapse settlement will not occur in soils which are located under the water table.Increase of moisture content. This could be seen as the cause for the collapse to take place. With the increase of moisture the colloidal coating loses its strength and thus forces the grains to a denser state with reduction in void ratio.Subjected to an imposed load greater than their overburden pressure before collapse can take plac e. This is only applied to certain collapsible soils.The typical problem associated with a collapsible soil to a building is that although it is dependent on the increase of the moisture content, collapse can take place years after construction has taken place. 6 Large magnitude settlements can occur beneath lightly oppressed structures as well as collapse settlement is regularly localised due to defects in foundation, waste pipe leakage and where ponding occur during rainfall.The engineering properties which most proceed the cost of a construction are alter compressibility. Both can be enhanced by reducing the voids in the soil. Water must be displaced from the saturated soils in army to centre the void volume. This can take months if the permeability of the type of soil present is low.The following engineering solutions to the mitigation of the collapse problem are listed below 6 evasion by stopping the triggering mechanism (increase in moisture). This can be made possible b y ensuring that water does not penetrate the collapsing soil horizons.Design for collapse. This could be possible in certain scenarios to design a structure which could withstand the predicted collapse settlement.Chemical stabilisation. This is to make use of a stabilising agent which could reduce the settlement.Piled or pier foundation. This is used only when the soil comes from a transported origin which means that the bedrock is cover with a shallow layer, making it possible to rather build on piers or piles.Removal and compaction. This could be do by removing the collapsible soil to a certain depth and replace it through compacting the remote soil in layers.In situ densification by surface rolling. Surface rolling can be done by making use of an impact or vibrating roller for compaction.Soil PropertiesBeach sand is one of many soils that have a collapsible grain structure, where its surface contains large quantities of calcium change which in more defined terms are remains of microscopic plants and animals that thrive on nutrients in the water surface, where it ultimately settles to the base of operations.The strength and the behaviour of this soil are thus dependent on the calcareous particles which it contains. These grain particles is well rounded due to it being rotated and shaped by the waves and is poorly evaluate (i.e. having a narrow particle distribution). This contributes to the high void ratio, meaning that the soil is very loose and can be seen as not a good bonding material. 6 defer 1 Transported soil and possible engineering problem.Soil TypeTransported Soil TypeAgency of transportationSourceProblem to anticipateBeach SandLittoral depositWavesMixedCollapsible grain structureTests to be performed on beach sandA large amount of data can be generated from soil, but it can all be wasted if the most measurable step of sampling is not carried out properly. Thus, in order for an analysis to be of significance to a proposed project, it should represent the bulk material of the site. Additionally, soil samples must be taken in abundance and at random, to ensure that the overall characteristics of the soil are effectively represented. See table 2 for properties beach sand.The following studys were used in classifying beach sand (collapsing soil structure)3Particle size distribution. This test is performed to measure the particle size distribution of the soil sample by passing it through a set of sieves. This is in order to produce a grading curve for the soil, which is used to find out its classification. The solid particles in a soil can have different shapes and sizes, and these characteristics thus have a significant effect on its engineering behavior. By making use of this test one can clearly note whether the soil is well or poorly graded. As for beach sand it is known to be a collapsible soil due to it having a poorly graded grain structure and affected by an increase in moisture.Atterburg limits. This test makes us e of three separate tests namely Liquid limit test, Plastic limit test and shrinkage limit test. This test is used to chequer a relationship between the soils consistency and its moisture content. If the soil has low moisture content, it would aim to break before deformation takes place, whereas if the moisture content is too high, the soil will deform more easily. This test is of great importance due to it having an impact on settlement underneath a proposed structure. The test can be used to distinguish between the presence of silts and clays. This is important as silt has much less coherence than clay.Dry parsimony. This can easily be rigid in a laboratory by measuring its physical dimensions and by weighing them. The dry density of a collapsible soil lies between 900-1600 kg/m3.Oedometer test. When a structure is build on a soil it produces settlement due to compression within the soil profile, which depends on the soils properties such as self-weight and also the type of load the soil is experiencing. This test makes use of a series of loads in order to measure the corresponding settlement of the soil. By knowing the soils stress and strain properties will allow the divination in settlement and swelling of the soil.Collapse Potential test. This test is used to determine the collapse parameters in order to design accordingly. The CP (Collapse Parameters) is given in percentage, to determine the level of severity.Triaxial test. This test is similar to the unconfined compression test, except that the sample is surrounded by a waterproof membrane and installed in a pressure chamber (cell). This test is thus performed to estimate the stress and strain parameters of the specific soil.Permeability. This test is used to determine the ease of which water can flow through a soil profile, which is important for geotechnical engineers in projects.Table 2 Soil properties of silt sand.9Soil PropertiesBeach SandSpecific Gravity2.64-2.66Bulk concentration (Mg/ M3 )1.82-2.15Dry Density (Mg/ m3)1.45-1.95Void ratio0.35-0.85Liquid limit (%)24-35Plastic limit (%)14-25Effective cohesion (kPa)75Angle of friction (deg)32-36Construction of Burj Al Arab FoundationConstructing a building on sea, an schmalzy island is needed to design and build the foundations. As many elements need to be taken into account to build an off shore structure, it is therefore important to ensure the protection of the foundation. This can only be done by evaluating all apposed loads to a structure. Seafloor stability regards to the bearing capacity and the sliding resistance thereof must be evaluated for static and combined static, operational and environmental (Like horizontal, vertical loading and overturning moments of the environment which have a return period of up to 15 seconds) loads. Structures with more or less a one hundred fifty meter depth could experience horizontal loads of 15-35% of the vertical loading, whereas the overturning moment can be ranging from vi tamin C to 500 million kN/m.8 The change in vertical load during a storm can veer from 10 40 % of the static vertical load. This means that the foundation needs to be strong to be able to obtain these loadings. Luckily these loadings were much less when Burj Al Arab was constructed, due to it only being 7 meters in depth.8IslandConstruction1.jpgFigure 3 Piling of the Burj Al Arab hotelThe first step in constructing the island was to place 230 concrete piles (see Figure 3), each one 40 meter in length, which was drilled into the sea bed. The foundation is therefore held in place by the friction of the sand and silts along the length of the piles, rather than the courtly bedrock. The surface was then made by using large rocks that were put together in a specific concrete pattern (honey-comb pattern) which serves as a shield to minimise erosion to the foundation.Making the chopine on which the building would be constructed, tube files and sheet files were drilled deep into the sea t o support sundry(a) boundary rocks. Once this was completed the sea water was displaced to fill the inside with concrete slabs as seen on table 3. IslandConstruction2.jpgThe structure was then surrounded with a temporary concrete structure to protect the island and the understructure of the structure, which was filled with a concrete plug slab. Lastly the concrete walls was made where the main basement floor of the building was build (See Figure 4).3Figure 4 Burj Al Arab Excavated BasementTable 3 Foundation of the Burj Al ArabConclusionThe Burj Al Arab being a geotechnical wonder is due to its size as well as its ability to withstand the environment and the impacts thereof. This building is only carried by a sandy soil which contains broken shells. Its ability under shear strength and pressure is very low, especially since it is located 280 meters of shore. Thus the building stands only on piles which are held into place by just the friction between the soil and the piles, making this project one of the most remarkable foundation types in history. The design of this foundation on this type of soil is breaking barriers in the building industry, making Dubai a leading country in development.Due to South Africa not being a first world country it is unimaginable for us to be examined to a city which encourages ultimate engineering in structural, hydraulic and geotechnical engineering. Therefore we cannot compare the infrastructures of their country with ours. South Africa could always strive to be a first world country by focusing on infrastructure as well as the inequality of societies. This would encourage tourism and affect the economy positively.