The Use of Manual Equipment: Design and Construction of Several Structures - Essay Example

Road profiling using laser scanning Introduction Profiling of roads utilizing laser scanning has evolved over time to become the most acknowledged geospatial data acquirement technology. This system was developed for both airborne and land based three dimensional collection of large volume of data regardless of perceived accuracy. The use of this technology has been fuelled by the discovery of computer technology and the direct geo-referencing technologies in early 1990s. The invention of lasers for purposes of road profiling has seen the emergence of solid-state rangers which have been found to provide powerful tracking functions. Laser profiling technology acts as a permanent replacement of tungsten and mercury based electrical distance measuring which were highly utilised in 1970s (Shan and Toth). Road profiling using laser scanning Laser profiling is normally used as the main technology in most infrastructural works for distance survey and carrying out midrange measurements. These measurements are carried out by phase comparison and pulse echo techniques as may be deemed fit by the road surveying agencies. Pulse echo technique is also applied in powerful solid state rangers which are applied in gunnery and tracking exercises within military cadres. Laser based electronic distance measuring machines possess standalone capabilities especially when the main function of their design is control survey and geodetic works whose approach is through traversing and trilateration. This equipment can also be used in measuring required angles in conjunction with specially designed theodolites. Laser scanners have also been incorporated into total stations which are specifically meant for enhance performance through introduction of such technologies as opto-electronic encoders. This allows for the topographic measurements to be carried out by surveyors and their respective assistants who hold pole mounted reflectors from the positions to be investigated. This process has been largely referred by the infrastructural surveyors as tachometry. The accelerated development of terrestrial laser scanners has also seen the introduction of road profiling scanners that are tripod mounted or mobile on vehicular platforms (Shan and Toth). Laser profiling through use of reflector-less rangers is done through a series of closely spaced points that are located next to each other within the terrain to be measured. In most cases this technology has been applied in two dimensional profiling (vertical) on grounds which show elevation of the measured ground along that very line. This is executed as a series of steps that are successively measured in slant ranges and vertical angles to the sample being recorded. This information is stored digitally for analysis through use of computer software once the exercise if fully completed. This analysis can also be done manually through the following derivations below (Shan and Toth). (1) Where: - Measured horizontal distance. - Slant range as measured. - Vertical angle as measured. (2) - Difference in height between the ground and the laser ranger. All these parameters can be presented as indicated in figure 1 below; Figure 1: Slant ranges with their respective vertical angles (a) and the required profiling variables (Shan and Toth). Where simple laser profilers are deployed for airborne exercises, this equipment is referred to as an altimeter. In this case, the laser is pointed vertically to the road under consideration in order to reflect back a rapid series of vertical measurements from a moving platform ideally a helicopter or a light aircraft. The airborne platform is expected to move forward or backward in a predetermined manner that will allow for measurement of a series of adjacent points along the projected path to be investigated. In advanced technology laser equipment, the successive positions are determined together with an integrated global positioning system or a tracker where necessary. This allows for extreme accuracy measures to be put in place when it comes to the analysis and presentation phase (Shan and Toth). In a smaller scale of the profiling exercise, laser technology has been utilised in carrying out investigations on the road surface layer texture. According to Bitelli et al. (2012), profiling of road texture is an important aspect of locomotion since it determines the resistance towards skidding by vehicles. Specifications and regulations have been set up on the acceptable standards of roads texture in order to provide for functional indicators. High precision laser scanners used for texture profiling use the triangulation technology in order to come up with a three dimensional analysis as opposed to the conventional two dimensional method which is considered as outdated and lack details. Laser scanners are therefore advantageous when it comes to texture determination through homogeneity and representativeness through single measurement as it does not require repetitive exercise. Digital terrain models (DTM) that are established under laser scanning were tested by Germany authorities as a pilot project for purposes of verification back in 1994. The laser scanning method having been a contentious issue in engineering survey was found to be a very promising procedure for handling and verifying data as opposed to the conventional methods during that time. Today, road profiling through use of laser scanning methodology has become universally acceptable and embracing it is a worthy course that is likely to save the face of engineering survey. Manual methods of data collection and analysis when it comes to the case of profiling have been drastically improved in terms of time and quality (Petzold, Reiss and Sto¨ssel). Conclusion The development of laser profiling technique has advanced the surveying field through cost effectiveness and timeliness. The fact that the survey process can now be carried out without necessarily having reflectors on the other end is encouraging. Automated report generation of points raised during rapid series of traversing which would rather be done manually has been made easier and faster too. The aerial profiling procedure has further quickened the profiling procedure due to the fact that laser profilers can be mounted on light crafts. Digital terrain models can be enacted in order to carry out research on road texture – a practice that has become widely acceptable. Works Cited Bitelli, Gabriele, et al. “Laser Scanning on Road Pavements: A New Approach for Characterizing Surface Texture.” Sensors (2012): 9110-9128. Electronic. Petzold, Bettina, Peter Reiss and Wolfgang Sto¨ssel. “Laser scanning—surveying and mapping agencies are using a new technique for the derivation of digital terrain models.” ISPRS Journal of Photogrammetry & Remote Sensing (1999): 95–104. Electronic. Shan, Jie and Charles K. Toth. Topographic Laser Ranging and Scanning: Principles and Processing. n.d. Robotic Total Stations and their Use in Design and Construction Introduction Robotic total stations are made up of electronic theodolite together with an electronic measuring device that are combined to come up with an integrated system for measuring of such parameters as vertical angle, horizontal angle and slope distance from a given origin. Total stations are designed by use of modulated near-infrared LED light that is capable of sending beams of light from the prism and reflect back without unnecessary losses. It is this portion of light that makes back to the instrument that is recorded and analysed for purposes of design and construction. Total stations are recommended due to their angle accuracy, distance accuracy and ability to record vast amount of data (GIS Resources). Use Robotic Total Stations in Design and Construction Over years construction contractors have used tape measures and other manual equipment to collect dimensional data for design purposes. These instruments pose as a threat to accuracy due to errors such as parallax, thermal gradients of the metallic or plastic tapes among others. Construction managers can today use the robotic total stations which are incorporated with building information models that are capable of achieving integrated measurements within a record time and maximum accuracy. While design work requires a team of individuals dedicated towards getting the work done, robotic total stations can be handled by one individual thereby reducing the costs of design and construction. This has been made possible by the invention of reflector-less total stations that apply intelligent tachometry and only involves automated collection of field data and analysis using integrated software (Kang, Ganapathi and Lee). Data generated from site survey is very important in design and construction as it aids in putting measures in place regarding any eventualities that may result from a given project. Based on this data, staff based at the field can start laying all the necessary points of purposes of construction commencement. The components of the building can also be surveyed through this technology to ensure that it is constructed as designed and that the tolerance range is within the acceptable limits. This is a proactive approach towards quality assurance meant to prevent subsequent conflicts that might affect the handover stage of a project. The information that is integrated in robotic total stations is dependent on set standards for quality and construction purposes. Total stations may also be used by contractors to identify the important features that are when it comes to finishing procedures. For design purposes, total stations can also be utilised for retrieving building coordinates from the model. This technology comes in handy as the coordinates locking function can be applied spotting points faster other than doing it manually (Kang, Ganapathi and Lee). Apart from data generation and analysis, robotic total stations can be used to manage design and construction data. This approach has been made possible due to the incorporation of building information modelling functions. These make it possible to come up with three dimensional representations of the building elements together with their spatial relationships, properties and their quantities. This information is useful for design, construction and eventually the maintenance of the building once it is handed over to the owner. Building information modelling is an important aspect within the robotic total stations owing to the fact that it is able to come up with important information in both three and four dimensional format and merge it with the existing construction schedule for actuating the progress. These simulations are responsible for the visualisation process and even make it appropriate for avoidance pf unforeseen circumstances. Presenting design data in three and four dimensions has helped in overcoming site constraints through quick calculations and sequencing of activities at construction sites. This form of survey by use of robotic total stations has been used in several sites to reflect on the situations at the ground (Kang, Ganapathi and Lee). The development of PosCon as an integrated system within robotic total stations by Liang et al. (2010) has seen the improvement of the existing building survey equipment. This is because, building components can be monitored on a real-time basis, updated and compared to the imported model without straining the user. This can then be analysed in order to quantify the amount of deviations that are expected in order to adjust before they even occur. During the construction stage, this function can also be utilised in keeping track of moving targets’ coordinates in order to calibrate their exact positions. This is however done by mounting reflective prisms on the target for sighting purposes. On locking the targets in their right positions, the modifications can then be made with respect to the calibrated deflections as identified from the target prism (Liang, Ming and Zhang). Another important use of robotic total systems in design and construction is the calculation of oscillation frequency. This is done by monitoring extremely low displacements of static targets with a frequency limitation of up to 10Hz. Smaller oscillating frequencies have also been made possible for extreme accuracies as the measuring frequencies have continued to increase with technological advancement. This technology has been very important in calibrating the vibration levels of such structures as bridges under various loading conditions. The dynamism that comes with this technology makes it suitable for integration of measuring functions for resonance frequencies which avert disasters that may beget the end users. Other common uses of robotic total stations in design and construction include; checking of boundary properties, making layouts for excavation designs, setting control points, as-built checks, topographical measurements and controlling lines for concrete pads in cases where the project has been subcontracted (Panos and Stiros). Conclusion The use of manual equipment poses numerous challenges to design and construction of several structures. The invention of electronic theodolite based robotic total stations has made it possible to carry out several design procedures ranging from design to quality control. During the design stage, robotic total stations are used together with building information modelling to generate various types of data that is paramount in design. This includes distance measurement, checking of boundary properties, making layouts for excavation designs, setting control points, as-built checks, topographical measurements and control lines for concrete pads. Works Cited GIS Resources. Total Station And Its Applications In Surveying. 2013. http://www.gisresources.com/total-station-and-its-applications-in-surveying/. 16 May 2014. Kang, J., et al. “BIM to field: Robotic total station and BIM for quality control.” eWork and eBusiness in Architecture, Engineering and Construction. London: Taylor & Francis Group, 2012. 717-722. Electronic. Liang, Xiong, Lu Ming and Jian-Ping Zhang. “On-site visualization of building component erection enabled by integration of four-dimensional modeling and autoby integration of four-dimensional modeling and automated surveying.” Automation in Construction (2009): 236–246. Electronic. Panos, A. Psimoulis and Stathis C. Stiros. “Measurement of deflections and of oscillation frequencies of engineering structures using Robotic Theodolites (RTS).” Engineering Structures (2007): 3312-3324. Electronic. Read More

In a smaller scale of the profiling exercise, laser technology has been utilised in carrying out investigations on the road surface layer texture. According to Bitelli et al. (2012), profiling of road texture is an important aspect of locomotion since it determines the resistance towards skidding by vehicles. Specifications and regulations have been set up on the acceptable standards of roads texture in order to provide for functional indicators. High precision laser scanners used for texture profiling use the triangulation technology in order to come up with a three dimensional analysis as opposed to the conventional two dimensional method which is considered as outdated and lack details.

Laser scanners are therefore advantageous when it comes to texture determination through homogeneity and representativeness through single measurement as it does not require repetitive exercise. Digital terrain models (DTM) that are established under laser scanning were tested by Germany authorities as a pilot project for purposes of verification back in 1994. The laser scanning method having been a contentious issue in engineering survey was found to be a very promising procedure for handling and verifying data as opposed to the conventional methods during that time.

Today, road profiling through use of laser scanning methodology has become universally acceptable and embracing it is a worthy course that is likely to save the face of engineering survey. Manual methods of data collection and analysis when it comes to the case of profiling have been drastically improved in terms of time and quality (Petzold, Reiss and Sto¨ssel). Conclusion The development of laser profiling technique has advanced the surveying field through cost effectiveness and timeliness.

The fact that the survey process can now be carried out without necessarily having reflectors on the other end is encouraging. Automated report generation of points raised during rapid series of traversing which would rather be done manually has been made easier and faster too. The aerial profiling procedure has further quickened the profiling procedure due to the fact that laser profilers can be mounted on light crafts. Digital terrain models can be enacted in order to carry out research on road texture – a practice that has become widely acceptable.

Works Cited Bitelli, Gabriele, et al. “Laser Scanning on Road Pavements: A New Approach for Characterizing Surface Texture.” Sensors (2012): 9110-9128. Electronic. Petzold, Bettina, Peter Reiss and Wolfgang Sto¨ssel. “Laser scanning—surveying and mapping agencies are using a new technique for the derivation of digital terrain models.” ISPRS Journal of Photogrammetry & Remote Sensing (1999): 95–104. Electronic. Shan, Jie and Charles K. Toth. Topographic Laser Ranging and Scanning: Principles and Processing. n.d.

Robotic Total Stations and their Use in Design and Construction Introduction Robotic total stations are made up of electronic theodolite together with an electronic measuring device that are combined to come up with an integrated system for measuring of such parameters as vertical angle, horizontal angle and slope distance from a given origin. Total stations are designed by use of modulated near-infrared LED light that is capable of sending beams of light from the prism and reflect back without unnecessary losses.

It is this portion of light that makes back to the instrument that is recorded and analysed for purposes of design and construction. Total stations are recommended due to their angle accuracy, distance accuracy and ability to record vast amount of data (GIS Resources). Use Robotic Total Stations in Design and Construction Over years construction contractors have used tape measures and other manual equipment to collect dimensional data for design purposes. These instruments pose as a threat to accuracy due to errors such as parallax, thermal gradients of the metallic or plastic tapes among others.

Construction managers can today use the robotic total stations which are incorporated with building information models that are capable of achieving integrated measurements within a record time and maximum accuracy.

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