Basement Car Park Design

Basement Car Park DesignA reportment car park has to be role in this disgorge to meet the property maturateers requirement. The car park result have 3 below grime take as the figure attached in the appendix ( paginate 2). A aim investigation has been completed and supplied as the selective in categoryation in this switch. The turn technique for the root cellar protects has to be identified, accordingly fancy the root cellar groynes and produce a report justifying the solution.1.2 hold Aim and target araThis confinement title is set up for student who is having their third course of study study in Civil and Structural Engineering. The objective lens of this bewilder is to muse the design and social organisation process of a geotechnical grammatical locution that students ar seeming to encounter in their future industry life. in that respect ar several(prenominal) aim have to be achieved in order to meet the objective in this project. Those aims argonTo g ain the over every persuasion in a project bodily coordinate and understanding those factors influence the development of the project.To gain thick(p)er acquaintance in the geotechnical field such as token of retaining social system and land profiles.To develop the sharp thinking and view of the form effectivity of the project.To identify the engine room capers in a project and minimize it to the minimum.To justify the proposed concepts into engine room fields.To apply engineering thinking into a project and design the social organization in accordance.To communicate with the supervisor for seeking take away advice and self study to complete the project.1.3 Project ScopeThis project had been separated into ii main parts which be conceptual design and elaborate design.In the conceptual design part, the choices of quite a little have to be considered wisely and justify it before get into the en rangy design part. In this project, on that point be several type setters case of retaining coordinate net be employ just just the most appropriate oneness depart be chosen to carry bring let on into the detailing design part. there ar few factors have to be pertain speckle selecting the choice of retaining organize. Those factors are the type of dirty word, durability, pass waterability, estimated approachs and an some other(prenominal)s. By having a good comparison among type of retaining twist, then the most adop remit type of retaining structure impart be selected to construct the retaining ring.For the detailing design part, an fitted design calculation has to be produced in order to show that the retaining structure is satisfied with several circumstances and sufficient drawings have to be disposed(p) if removeed. The reflexion sequences have to indentify and list out clearly. Last plainly non least, a detailed rule statement for the safe anatomical structure of the mental synthesis including any supporting risk of infection assessments, and an outline construction programs in the form of a bar have to be provided.2.0 Back country Study and ConstraintsThe land study is the first stage of this spotless project and a subject field must to be through with(p) before a project produce to progress on. The main purpose of this stage is to gather information as much as come-at-able and analysis to figure out the barrier of the project.thither must be or so(prenominal) restriction in each single project that has to be dreaded and further rational thinking to manipulate a good design. The discussion of the constraints has to be done in the early part of the project then the better final design will be produced by passing through this process.2.1 Deep minelaying and SiteThe state of affairs tolerance is hold referable to a everyday gameway located just undermentioned to the footpath which is 2m away from the site. There must be well-nigh disturbance will face by the public highw ay ascribable to this significant outlet. This invest has to be considering magical spell choosing the type of retaining structure to be construct and minimizing it to the minimum when the construction is discharge on.Deep excavation has to be fetching part in this full project, so the hazards of deep excavation every supported or single-handed case has to be indicated and it is a considerable concern while reservation decisiveness for the type of earth retaining structure. For example, the de piddleing problems might be exist base on the piddle plank and the excavation is variable base on dissimilar type of acres in the plain as well.2.2 mark ProfilesThe undercoat profiles are the arouse and concerning part for the geotechnical engineering e in particular the engineering grimes found beneath the summit meetingsoil 1. The engineering properties and the behaviour of these soils are their concerning and interesting point 1.Different type of soil profiles will be ha ving several(predicate) ability for a structure. thereof, site investigation process has to carry out to determine the soil profiles. The layer and the type of soil or tremble beneath the ground surface will be determined by this process. Its behaviour and the properties of each layer will be obtained as well to progress on.In this project, there are three boreholes given from the site investigation data which named as BH-02, BH-03 and BH-09. The boreholes record is attached at the post of the report which in the appendix part (from page 1 to page 2). The location of BH-02 and BH-03 are shown inside the cast view of the site unless there is nonhing relevant to BH-09 can be figured out from the view. The plan view is attached in the appendix (page 1). A easy analytic of the height and astuteness of each layer have done which shown in the body-build 2.1, 2.2 and 2.3.CUsersFuhDesktopZzz_Study thingsCIVE 3709ProjectIMG_0619.JPG work 2.1 Borehole Record, BH-02CUsersFuhDesktopIM G_0617.JPG see to it 2.2 Borehole Record, BH-03CUsersFuhDesktopIMG_0618.JPG prototype 2.3 Borehole Record, BH-09From the figure of the three boreholes records, it shown that they are round the similar. The soil profiles for the top layer is made ground then followed by cadaver and then mudstone as the bottom layer.Clay is a naturally occurring material quiet primarily of fine-grained minerals, which is generally plastic at appropriate weewee contents and will harden with desiccated or fired. Although clay ordinarily contains phyllosilicates, it may contain other materials that impart plasticity and harden when dried or fired. Associated phases in clay may include materials that do non impart plasticity and organic matter 14. In the other hands, mudstone is a fine grained sedimentary rock which is organize by clays or muds with the atmospheric pressure over long time. It looks like hardened clay simply depending on the status when it was formed.2.3 Water levelGroundwater o bservation where the water seeps or immersion has to be recorded in the site investigation logs as they affair with the casing and the boreholes shrewdness 2. Groundwater observation is the concern for geotechnical engineering due to the water pressure too. The water pressure is an issue that will affect the decision of the choice of retaining structure and the depth of the cat sleep as well.The water table is not given in this particular project specification thus proper comity is needed before making any assumption. The water level is to be assumed one meter below ground level after a long consideration and communication with supervisor. This should be the ruff assumption and go on for the later part of design.2.4 Time, cost and QualityAs a designer, the concern of the property developer has to be taking into consideration while designing a project. Time, cost and quality are playing the important roles for a single project which will be the concern of the developer. These three elements are the key issues and related to each other. The cost of the project will be incr quietus if a project construction time getting longer. Base on this, the shorter the construction period the move the cost of the project so a proper planning of the construction method and procedure is needed to minimize the construction cost but the quality of the project must be cool it maintain in a satisfy adoptable level.3.0 Type of hide Retaining StructureEarth retaining structures are mainly employ to support the soil and structure due to the difference in elevation of the ground surface. It can be either propped or cantilever. There is various type of earth retaining structures which are used in geotechnical field for civil engineering. Those retaining structure much than commonly used in basement car park and more suited for this project are yellow journalism gage argues midriff Walls bore fold WallsThere is different capable of each type of wall, the typical applic ations of walls have shown in the figure below.Figure 3.1 Typical applications of embedded walls (8 pages 98)3.1 Sheet Pile WallsSheet plenty walls are made of timber or pre estimate cover previously but nowadays rag week mass walls are more commonly made of make. Sheet backpack walls are formed by individually operate sheet plug into the ground and form the series of interlocking arrange to support the soil and the structure 1. Sheet forty winks wall can be category into two main types which are cantilever wall and anchored wall.Sheet rafts are light to carry on and being robust. It can handle the high compressive fills whiles it operate into a hard ground surface 3. It has the ability of being drive into deep penetration to reach a bearing stratum or to develop a high frictional resistance 3.There are two method of ride sheet blocks into stratum which isPitch and jampackThis is the simplest method, each sheet visual sense or pair of wads will be driving into the finished level (full depth) before repeating the next sheet pile. By the way, this method is preferable for loose soils and short piles only.Panel DrivingIn this method, the first pair of piles has to be pitched carefully, plumbed and determined partly to form adjacent piles. Then, the remaining of piles are pitched and interlocked. Finally, the last pair of piles pitched into the control board are then driven partially and followed by the partial driving of the rest of the ornament, working back towards the first pair in the panel 4.The piles is arranged as whole panel, therefore it is no need to drive all piles fully to maintain the piling operations. The risk of driving problem and difficulties of de-clutching will be minimised too 5. This method is commensurate for dense anchors and awry(p) cohesive soils.http//www.earthwork.us/files/DSCN2063.JPGFigure 3.2, Sheet Pile WallsThere are few issues have to be discuss while considering to be used sheet pile walls for design. Firstly, the deep of the basement has to be constructed. If the depth of the basement too deep which mean the duration of the pile will be quite long and the ability of enthraling, pitching and driven those piles has to be taken into consideration especially in urban world. Cost will be affected in this issue as well because it is hard to manufacture a big(p) surface of sheet piles.Basement car park recently constructed in urban area to fully utilize the distance in the cities. While sheet pile walls can be act as a eternal structure or temporary work in a construction project, but there is a concern if the sheet piles act as the temporary work. The ability to remove the sheet piles after constructed the retaining structure has to be think twice base on the limited spaces rough the cities for the crane to remove it.Even there is some improvement of the engineering science on the racquet and vibration problems for sheet piles while driven it into the stratum but vibration and noise are still slide by which is the dis receiptss of sheet piles. The improvement just mainly overcomes the problem on some type of soil layer only, such as by victimisation some hydraulic pressure equipment to press the sheet piles into annoyed clay layer. Refer to this entire issue there must be rational consideration if steel pile has to be used specially in the urban area.3.2 Diaphragm WallsA full point wall essentially is the combination of strengthen concrete wall and sheet pile wall. It has the ability of the combination of reinforced concrete and sheet pile wall. A stay wall are formed and fixed by vertical reinforced concrete slab in position with the same manner to support the soil. In the other hand, the sheet pile held in the lower part of the check wall by the passive and active soil pressures that act upon it 1. almost of the midsection walls are the reinforced concrete wall that cast in situ by a machine digging a chuck in panels of limited continuanc e. It acts as temporary support during construction and a permanent wall, sometimes with lining 8. The stability of the excavation to the required depth is fill by the use of a drilling fluid, usually is bentonite slurry 6. This slurry has thixotropic properties, as it forms into gelatin when left undisturbed but becomes a liquid when disturbed 1. The bentonite slurry initially penetrates into the soil and the virtually impervious skin of bentonite particles is formed 1. It is only about few millimetres thick on the sides of the ditch. There is no penetration of the slurry into clays, sand and silt water. The main purpose of the use of slurry is to prohi smear collapse of the trench by creates lateral pressures that act on the side of the short trench panel.When the excavation is done, the required steel reinforcement is place into the trench panel. The walls are constructed by change with concrete in discrete panel distances ranging typically among 2.5m and 7.0m using purpos e in appropriate circumstances. Those displaced slurry being self-collected for killing and further use. Standard widths of midsection walling equipment are 600, 800, 1000, 1200 and 1500mm although greater can be provided as required. Depths of the diaphragm wall are constructed up to 50m by using grabs and up to 80m using standard hydromills (milling machines). The remaining intermediate panels are excavated and constructed to fully complete the wall when the concrete has developed sufficient strength. The length of each panel is limited to the amount that the soil will arch, in a horizontal direction, to support the ground until the concrete has been placed 6.A simplified Figure 3.3 has been attached to shown the various construction stages. In the Figure 3.3, the processes of each stage areGuide-wall constructionPanel excavation in progressInstalling stop endsPanel concretingFigure 3.3, the stage of construction a diaphragm walls.http//www.stroyinject.com/images/gallery/pics_n ew.08.08/thumb_SZ_2.JPGFigure 3.4, Diaphragm WallsThere still exists another type of diaphragm walls which are precast reinforced concrete diaphragm walls. The use for this type of diaphragm wall is nearly the same with diaphragm wall that reinforced concrete cast in situ. It provides both temporary and permanent soil support but with limited depth.There must be some advantages and disadvantages for every single earth retaining structure. Therefore the discussion of pros and cons for this type of retaining structure has to be done, while considering of using diaphragm walls.The construction time and cost of diaphragm wall is generally streamlined where it is used for both permanent and temporary subsoil retention for walls of medium, and greater, depth 8. Diaphragm walls also allow the effective raptus of vertical load from the building superstructure to subsoil below basement level. The vertical load wobble is not added in the wall design while the early of diaphragm wall in UK. The reluctance of designers to allow such load transfer was due no doubt to lack of published test results. This situation changed gradually when the diaphragm more commonly use in the construction of basement 8.While constructing the diaphragm walls, it has the minimum noise and vibration disturbance. This is an advantage of using diaphragm walls as a retaining structure. The noise and vibration in diaphragm wall installation are about the same equalize with the normal civil engineering equipment, such as cranes and generators. Base on this, it suitable to be constructed in urban area. Diaphragm walls can be constructed under groundwater position so there is not any friendship in groundwater problems for this kind of structure. Diaphragm walls have the advantages of high bearing cleverness and good in horizontal or vertical bearing capacity. The allowances of resoluteness for this kind of structure are small which is good for superstructure 9.Although there are many advantage s of using diaphragm wall but there is some limitations for this structure to be used. It could not be use either in very soft soil such as soft clay due to trench stability problem or very stiff rock.The principal disadvantages of diaphragm walling are the risk of loss or waiver of bentonite slurry, the relatively high cost of cleaning and the disposal of the slurry, the site space needed for large reinforcement cages and the large cranes needed to handle them. higher up all, the need for continuity in the construction process from excavation through concreting to removal of temporary stop formers is a disadvantage of the method 8.A good quality control is needed in the diaphragm wall construction. Diaphragm walls are the new type of retaining structure which is more mod and construct by some modern equipment. Those skilful and more specialist workers needed while installation the walls.3.3 world-weary Pile WallsBored pile walls are an earth retaining structure that form by b ore cast in situ piles either small or large diameter. This technique often used in deep basements and underground structure as a temporary or permanent retaining structure. It commonly used for those structures with limited working space or constraint of adjacent existing structures that prevent excessive bulk excavation and help to control the movement of the ground 6.The construction method of blase pile walls are slightly different compare to the diaphragm wall, initially a casing has to be driven into the ground by using the vibro-hammer and leaving 1 metre length of the casing above the ground. Casing can be ignored where the soil profiles are profligate to stiff cohesive soils 11. The power-driven rotary gimlet (a drilling tool) will be used to cut and remove the soil deep down the casing to form a borehole. The range of diameters and depths possible is considerable, from three hundred to over 5000mm and down to 100. The used of the casing is to support the surrounding s oil. If the length of the casing not enough long to reach the required depth in the ground, bentonite slurry could be used to support the soil below the casing. The steel reinforcement will be lifted up and placed into the borehole by crane. If the depth of the boreholes too deep, reinforcements have to be over lapping and conjoin if possible. The concrete is poured into the borehole to form the tire pile. Finally, the bored pile is formed by using the vibro-hammer to withdrawn the casing 310.A bored pile wall has its own distinction that have to take into consideration while selecting the type for retaining structure. The presence of the advantages and disadvantages of the bored pile walls have to be taken into consideration if bored pile walls chosen to be used.The length of bored pile walls can be varied to suit the varying ground chequer which is more adoptable for most of the design project. Moreover, the soil can be inspected and if necessary sampled or in situ tests made when it is cut and removed from the boreholes. By using this method, the large excavations and subsequent backfill are eliminated. The noise and vibration are existed while constructing the bored pile but it is acceptable and will not disturb the adjacent pile or structure 12.Basically, the disadvantages of bored pile wall are not much. The transportation of the casing could be one of it. The unable to place the concrete under the ideal condition and cannot subsequently inspected are one of the disadvantages as well.Figure 3.5, the steps of constructing contiguous bored pile walls.Bored pile walls are categorised into two types, which areContiguous Bored Pile Walls second Bored Pile Walls some(prenominal) factors have to be concerned while choosing the type of bored pile walls. Those factors areSoil TypeThe ground water profile social structure time availablePropping requirementsCostLife span3.3.1 Contiguous Bored Pile WallsA single dustup or double row of piles pitched and constr ucted next to each other with leaving some crannys. Alternative piles are cast first and the intermediate piles are then installed. Figure 3.6 and Figure 3.7 are attached for more detail and understanding. For this type of retaining structure, the water will flow through the gaps mingled with piles 1. This type retaining structure suitable where the soils are between firm to stiff and the water level is below the depth of excavation. This method is the accelerated method and most economic option to construct.Figure 3.6, an example for the plan view of contiguous bored pile wallhttp//www.sbe.napier.ac.uk/esm/images/bored_pile_small.jpgFigure 3.7, contiguous bored pile wall3.3.2 sec Bored Pile Walls s bored pile walls are similar with the contiguous bored pile wall, except that the gap of the piles are either filled with concrete or secondary pile are cut into the autochthonic piles as shown in Figure 3.8 and Figure 3.9.This technique is suitable for high water level due to the co ntinuous wall had formed and it is a bulletproof condition that stops the inflow of water. The procedure of this method is slightly more complicated compare to bored pile wall.Figure 3.8, an example of plan view of secant bored pile wallshttp//www.amplusltd.com/upldimages/ISecant%20piled%20wal%20-%20Battricks%20-MG_0042.jpgFigure 3.9, Secant bored pile walls4.0 Comparing and Selecting Of Retaining Structure.By using a simple matrix analysis table as shown in mesa 4.1, it can be determined the best selection of retaining structures as in general concept. The selection of the retaining structures can be determined by rational comparisons by applying the weighting into the matrix table. The weighting in the matrix table are represented with numerical numbers from 1 to 3 in which the higher the rank, the more beneficial for the route while the lower the value indicates as otherwise.From the table, it shown that each type of the retaining structures is about the same, they have their o wn characteristic and advantages in different aspects. Secant bored pile walls gained the most point in the weighting but it might not be the best choice because this is just a general concept comparing within the type of retaining structures so a proper comparison that fit with this entire project issues will be done later on.The soil profiles of this project are made ground, firm to stiff clay and mudstone which adoptable for all of the retaining structure mentioned above except sheet pile walls. In this soil conditions, sheet pile walls are not suitable to be driven into the ground due to the hardness of the mudstone layer. This problem can be work by providing bigger size of sheet pile which significantly increased the cost and waste of materials. Therefore, sheet pile walls are not recommended and if possible choose other type of retaining structure into design.Water level is a problem which will be affected the decision of selecting retaining structures. The water level is to be assumed at 1m below ground level. It is quite high and proper consideration has to be done base on this issue. Diaphragm walls, sheet pile walls and secant pile walls are capable to construct in high water level condition. Contiguous pile walls are not able to construct below ground water condition due to the gaps between the piling which allowed the inflow of the water. This might a concern while selecting this as the retaining structures.Diaphragm walls are a good retaining structure among all of the retaining structure. It allowed the highest depth of excavation which is about 7 to 30m length but 8m of excavation is sufficiently enough in this entire project. In the other hand, the other retaining structures are more adoptable which allowed 4 to 15 or 20m depth of excavation length. This will be an issue while selecting the choice of retaining structures.Basically, there is specific difficulty of constructing each type of retaining structures just in different restriction. Th ere is not much to comment on the ease of construct issue but it must be fit with the site restriction. The durability of each type retaining structure is about the same and it could be ignored while comparing with each other. The cost of construction must be minimizing to the minimum if possible because it is a concern of the project developer and frugal problem.Sheet pile walls are rejected in this project due to several concerns. First, the main concern of using sheet pile is the size and area of the pile to be used due to the depth and area of excavation are quite big. It is hard to manufacture such big size of sheet pile in the factory and hard to transport large number of them to the site. If sheet pile chosen into design for basement car park, it will commonly act as temporary work and the ability to withdraw the sheet piles after the construction is an issue because a highway just located 2m away from the boundary of the site. Moreover, the soil profile contains lot of the mudstone which cause the sheet pile hard to be driven into the ground. There will be some vibration which will be affected the public highway either on the intro or the whole structure while the sheet pile is driven into the ground.Diaphragm walls are good to be used in basement construction which is commonly in urban area. Honestly, it is capable with all the construction constraints in this entire project such as it is able to construct under groundwater condition and there isnt any vibration problem in diaphragm walls construction. Even it is so good compare with other retaining structures but it still will not be selecting as the retaining structure. First, large amount of steel reinforcements needed for a diaphragm walls, it have to be tied up before they lifted up by crane and placed into the panels. Base on the number of materials and skilful workers needed, the cost of the construction will increased directly. It is also relatively high cost of cleaning and the disposal of the slurry. Diaphragm walls are good enough which is a bit over for this project because some of the advantages is not needed in this project. Consequently, diaphragm walls are not suitable for this project and some other retaining structure will do because the overall estimated construction cost is too expensive compare with others.Bored pile walls are the most adequate retaining structure to be used in this project compare to the others. Even there are some disadvantages in this type of retaining structure but the advantages of using it are higher after proper consideration and comparing. Then, the vibration and noise of constructing bored pile walls are in the acceptable range and will not affect those structure next to it especially the public highway. Bored pile walls are able to consort with the soil conditions in this project too. It is the cheapest retaining structure as well. Bored pile walls are chosen either secant bored pile wall or contiguous bored pile wall.As a conclu sion, secant bored pile wall is chosen as the retaining structure in this project because it offers a watertight alternative compare with contiguous bored pile walls.4.1 Selected Retaining Structure Secant Bored Pile WallsSecant bored pile walls basically are bored cast in situ piles either small or large diameter. It will be constructed in a line and the gap between piling will be choice with cement or concrete to form a watertight condition for preventing the inflow of water. The filling technique will be mentioned in the later part of report.Secant bored pile walls are categorised into 3 types which are unverbalised / Soft Secant Pile Wall expectant / Firm Secant Pile WallHard / Hard Secant Pile Wall4.1.1 Hard / Soft Secant Pile WallThe female pile has a characteristic compressive strength of 10-20 N/mm2, which is retarded to reduce the strength of the mix while the mail piles are drilled between the female piels.4.1.2 Hard / Firm Secant Pile Wall4.1.3 Hard / Hard Secant Pile W all