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Importance of survey

In this blog I will discuss survey, and different tools and software for creating images of existing plant. Normally, engineering companies hire contractors to do survey work, and deliver topographic surface in Civil 3D which is imported into 3D model. Sometimes, contractor will submit 2D drawings in AutoCAD showing all survey point. Please see the figure below.1-survey-points

Important to note that survey must be done in the way that survey datum must coincident with your 3D model datum point. Please see the figure below.
2-survey-points-datum
Sometimes survey is done by taking plant origin as a datum point. In that case, the datum point for your model is the plant origin. Since you have survey point, topographic surface can be made by using Civil 3D  and imported into your plant 3D model. Here is tutorial on importing points into Civil 3D, and here is tutorial on creating topographic surface in Civil 3D.  If you work on existing plant, sometimes scan image of existing paint might be required, and Leica Cyclone is excellent tools for model based on scanned image. Please see figure below.
3-scan-good
Leica Cyclone is software, easy to use and learn. Because of simplicity, special training is not required, and after reading the manual you will be comfortable working with software. Survey is very often neglected in cost estimation, but it can be expensive and impact total cost, especially if you work on a small or medium size project and laser scanning is needed. On the other hand, survey will provide you peace of mind. I had the case where survey confirms that grade elevation is one foot higher than what is is shown on drawings that are made in 70’s.