Surveying in Construction - Assignment Example

?Client’s 10 August Surveying is an integral process which requires the right use of the right equipment. Surveying is extremely important because it determines how a construction company is going to go about a certain project, several major problems may be realized during the process of surveying and several major problems may be ignored which will affect the project gravely, this is why it is pivotal for a professional to complete the process of surveying efficiently. Several tools are required to complete the process of surveying; this paper will shed light upon the uses of different tools and other important equipment. Surveying Terminology: Foot Print is a common surveying term which refers to the perimeter walls of a building or the outermost boundary. All the exterior walls are included when the surveyor is taking the foot print. Elevation is another common surveying term which refers to the height which is usually above sea level. This point usually describes the house which is to be constructed and how high is it from sea level. Site plan is a very common surveying term which includes all the dimensions; the site drainage is often the most important point when the site plan is being talked about. Monument refers to marking, a position is marked which is used for future reference Heading usually refers to direction which is magnetic and is determined with the help of a compass Tolerance refers to the precision of a measurement and it is a mathematical term which is very important when it comes to the process of surveying Architecture and trigonometry go hand in hand; it has several major uses when it comes to surveying sites and determining solutions to various arduous problems. The curving surfaces need perfect calculations only then one can build buildings, without the proper use of trigonometry these buildings would just fall after a few days. It is imperative to determine the proper height of a building and that is where trigonometry comes into play, creating dimensional objects also require the much needed assistance of trigonometry. The demarcations of cubicles can only be determined by the proper use of trigonometry, these cubicles are crucial in an office building. It also determines the no of people required to complete a task because it lays out a structure on which the construction workers work upon. Having accurate measurements gives a building its strength and this is unimaginable without the proper use of trigonometric ratios. The following will serve as a classic example to prove the above point: A surveyor who has been asked to lay out a design for a bridge goes and calculates the width of the river over which the bridge is to be constructed, the surveyor has to apply the sine and the cosine ratios to be able to calculate the width and lay out a proper design for the bridge to be constructed only then the workers can start the work. This is why trigonometry is extremely important and all the top constructions engineers are really good at mathematics. Common Surveying Equipment: The following section will comprehensively present the most common surveying equipment. Measuring Wheels: Measuring wheels are very widely used by surveyors to measure distance from one point to another. These measuring wheels become all the more important when the surveyor is in a hurry; they are employed when distance is to be measured in a hurry. These measuring wheels come in different shapes and sizes, the small wheel is employed for indoor measurement, the medium wheel is perhaps the best as it can used both indoor as well as outdoor and lastly there is a large wheel which can be used only for outdoor purposes. Compasses and Clinometers: Slope readings, sight directions and height readings become easier to take with the help of compasses and clinometers. Brush Axes: Brush axes are mainly used to clear the area which is blocking the line-of-sight; it is always good to carry extra axes just in case the surveyor breaks his axes. Automatic Levels: Automatic levels are great tools which enhance accuracy, leveling is difficult to measure and these tools make this arduous task a walk in the park. These are very commonly used tools by the surveyors. Task 2: Checking the tripod is very important when it comes to leveling, the tripod should always be on stable ground to avoid problems in the future. Vertical standing axis is set up by using the pond bubble. The parallax error should be eliminated every time it appears. It is also very important to know whether the compensators are working or not, the compensators must work correctly every time only then can leveling be accurate. The instrument and the staff should never move together, it is always either of the two. Either the staff should move or the staff should move the instrument without moving, the leveling will be inaccurate should both move at the very same time. There are several errors in leveling that are possible, collimation error is one such error, it happens because of several errors in equipment. This is why it is very important to use the right equipment to get the right results. The parallax error is also very common in leveling; this should be avoided to get the right results. Staff errors and tripod errors are some other errors which must be avoided at all times. Setting everything up: The survey station and the tripod head are the two main focal points, the head of the tripod should be level and it should be over the survey station. It is very important to focus on the feet of the tripod; they should be fixed properly in the ground. These steps must be incorporated before the theodolite is removed from the box. Once the theodolite is placed on the tripod the legs of the tripod must never be moved however, the legs can be adjusted slightly. The theodolite is then placed in the centre of the tripod and the screws are tightened. After this the instrument is turned on. The pond bubble should be brought to the centre by adjusting the legs of the tripod. It is very important at this stage to ensure that the theodolite is leveled and centered. Adjust the display screen in a manner in which it is over the two leveling foot screws. The laser plummet should also be checked to ensure that it is over the survey station and the theodolite is placed in the centre of the tripod stand. It is also important to check the accuracy of the plate level bubbles this can be done by rotating the device 180 degrees. Once the theodolite is placed in the centre of the tripod stand and placed over the survey sight press ok to measure angles. The drawings are really important as they serve as rough sketches of a building; a lot of effort goes into these drawings. Measuring equipment is used to collect and record data, such measuring equipment has already been discussed in this paper, measuring is just the first step. It is extremely important to make a note of these readings and it is also important to note other important issues which need to be solved. The next important step is to check the accuracy during and after the survey to ensure that everything important is at its right place. The collected data is usually in the form of dots and other symbols which is later joined together to make drawings and this is how the progress takes place. Below is a classic example of surveying. (Survey Points) This is a classic example of linear or two dimensional surveying, a driveway, house and a garage can be seen in the figure above. This is how the data collected is joined and given the form of a drawing. It takes a lot of effort and precision to do this; this is why professionals are hired for this intricate job. Task 3: There are two most widely used methods of leveling and they are height of collimation method and rise and fall method. Height of collimation method is believed to be much easier than the rise and fall method. It is said to be easier because the levels can be easily reduced when compared with the rise and fall method. It is ideal to use this method when more no of readings are to be taken and when the change points are usually less. On the contrary, rise and fall method is very difficult. It takes a lot of time to reduce the levels. It is ideal to use this method for check leveling. The height of the instrument is of prime importance in height of collimation method, for each setting of the instrument the height of the instrument is added, “this is done by adding the back sight to the elevation of BM. Here is an equation which will facilitate better understanding of this concept. HI=BS+RL of BM = RL of the plane of collimation.” (Basics of Surveying) It is also important to understand the concepts of face right and face left. These concepts are essential in understanding how a surveyor works. These are both observations and are done by using a telescope. It is face left observation when the vertical circle is on the left side of the telescope and it is called face right when the vertical circle is on the right hand side of the telescope. Elimination of parallax remains a constant challenge during the process of surveying, a surveyor must always be aware of this parallax problem. It has the ability of greatly influencing the results and this should be kept in mind at all times. The rise and fall method has its advantages and the height collimation method has its own advantages. The height of instrument method is much better than the rise and fall method because of three most important reasons; it is quicker, less tedious and most importantly simpler. Height of instrument method may ignore grave mistakes because of the simple fact that there is no check on calculations which is available. Rise and fall method on the contrary provides a complete check on calculations; this is why it is called a very tedious method. Height of instrument method is really useful when a series of readings are required without altering the settings of the instrument. It is ideal to use rise and fall method when there are a plethora of intermediate stations. It can also be used when there is a long run of differential leveling. These are some of the ideal situations in which the rise and fall method can be employed. Task 4: “Setting out is a fairly quick exercise in the scale of things, but obviously it has to be done with great care.  A few of the things that I will be mentioning below might sound like I am writing a how to for dummies.  Believe me mistakes made in the setting out can come back to haunt you. I have heard of houses being built on the wrong blocks.” (Setting Out) “With the location plan in hand, the builder can prepare both plot and site for the construction of the building. The location plan tells him exactly where the trees and bushes have to be removed so that they don't interfere with the work. This preparation includes making a drive, cutting the grass, and leveling the surface of the ground. The builder must pay special attention to the roots of trees which are on the site or very close to it. These must be completely removed. If some roots, such as those of the neem tree, remain in the ground, they can grow again and damage the structure.” (Planning and Setting) Setting out a very important procedure and utmost care should be taken before this procedure gets underway. The permits to build at a particular location should be obtained. The block plan has to be accurate and immaculate to prevent any problems in the future from occurring. The boundaries must be marked with all the right angles and other important measurements. Every fence line should be checked thoroughly. Below is a fine example of how pegs are set out. (Setting Out) Setting out profiles: Below is a diagram which sheds light upon how to set out profiles. (Setting Out) Mostly rectangles are used in building and the following properties of a rectangle are employed in setting out: Rectangle has four angles and each angle is 90 degrees. This is how the base line is usually set up. Parallel opposite sides. Equal length of the diagonals. With the help of these details a proper check can be conducted. The accuracy of profiles ensures that the drawing is well constructed and the workers can go ahead with the structure. The same has been explained with the help of the rectangle example. “Setting out is the process by which information is taken from the construction design drawings, to enable pegs, profiles or other marks to be set so as to control construction works, and ensure that each element of the works is constructed in the correct position and to the correct level. In some senses setting out is the opposite of surveying but the instruments and basic principles of measurement and accuracy are the same and people will often work in both disciplines.” (Unit Abstract) To conclude it is very fair to say that surveying is a very complex procedure which involves a lot of care, accuracy and effort. There is a great need to have trained professionals who can pay attention to errors like parallax error and rectify it in due course of time so that the same does not affect the construction in any way. All the angles should be perfect; there is hardly any scope for a mistake. It is safe to conclude that surveying requires great mathematical and analytic skills which not too many people possess. One should be through with the trigonometric ratios so that he can easily carry out the intricate calculations, a person who has little knowledge of mathematics can never become a good surveyor. Works Cited “Basics of Surveying.” Height of Collimation Method. n.p., Web. 10 August. 2011. Unit Abstract (2011). Surveying in Construction. n.p., Web. 10 August. 2011. Planning and Setting (2011). Surveying in Construction. n.p., Web. 10 August. 2011. “Survey Points.” Linear Survey. n.p., Web. 10 August. 2011. “Setting Out.” Pegging Out for a Slab. n.p., Web. 10 August. 2011. Read More