Preparation of Skeleton of Alignment

Input Required:

1) The list of IPs and their respective chainages.
2) The list of Bearings from IP to IP.
3) The details of curves proposed at each IP from the design department.

Procedure:

1) Create a new drawing in AutoCAD with Metric units.
2) Use the command ‘UNITS’ and set the units to be as following.



3) Click Direction Button and set the base angle to ‘North’ as below.



4) Now assume each drawing unit to be a Meter in actual.

5) Add a Point Entity at any point in drawing space and mark it as the start point of the alignment. Let this start point of the alignment be the first and present IP of the alignment.
6) Add the next IP to the drawing by adding another Point Entity at a distance (in meters) relative to the present IP at an angle equallant to the bearing (in deg/min/sec) between these two IPs. Join these two IP points with a line. Change the lineweight of the line to 0.3mm and color to ‘Red’. If the alignment is alternative set the linetype to ‘Dashed’ and ltscale to 12.5.
7) Draw all the IPs and End point in the same manner and mark the chainages for each and every IP including the Start Point and the End Point. Set the text height of the chainages to 6.25, color to ‘Green’ and font to ‘Arial’.
8) Add a curve at each IP tangential to the alignment with a radius (respective to the IP) given by the design department. Change the line weight of the curve to 0.3mm and color to ‘Red’. If the alignment is alternative set the linetype to ‘Dashed’ and ltscale to 12.5.
9) Break tangents of the curves from the main line of the alignment. Join curves to the main line using command ‘Pedit’ and make entire alignment a single element. Set the linetype of the tangents to ‘Dashed’ and color to ‘Black’.
10) Mark the chainages of 1Tangent Points (TP1 & TP2) for each curve. The chainage of TP1 may be worked out by adding straight distance to this curve from previous TP2 or Start Point of the alignment which ever occurs to the chainage of the respective point. The chainage of TP2 may be worked out by adding Length of the Curve to the TP1 of Present Curve. Set the text height of these chainages to 5.0, color to ‘Black’ and font to ‘Simplex’.
11) Change base angle of the drawing to ‘East’.