SURPAC Surveying Software 


A Horizontal Alignment (or Centre Line) file showing information for a Curve


  Horizontal Curve and Straight Alignment


Given a set of user defined parameters for a road or railway route containing a series of horizontal curves, this application will compute the [Y, X]  (or [E, N] ) co-ordinates and Chainages of positions along the centre line of a route, or along a defined Offset Line. 

The required input parameters are :-

The  [Y, X]  (or [E, N] ) co-ordinates for the Start  and  End  points of the section of the route to be computed, plus the chainage of the Start  point. These Start  and  End  points represent the total length of the centre line, or offset line, to be computed.

The [Y, X] (or [E, N] ) co-ordinates for the Points of Intersection for all curves lying along the defined route (up to 100 curves).

The circular Radii for all curves lying along the route.

The lengths of all Transition curves, if any, for all the curves along the route.

The Chainage Interval required between Centre Line points. 

Selection of Centre line or Offset calculations.

The route section can also be as long, or as short, as required.  It may consist of a single curve (where the start and end values may be coincident with the BC and EC points), or a single straight. The maximum number of points on any Centre Line file is unlimited.

Once a route, or section of a route, has been computed, this application may be used at a later date, for the editing of any of the curve parameters, if required. Curves may be Added, Inserted, Modified or Deleted from the original scheme. Any number of updates may be made and the Centre Line co-ordinates re-computed and re-stored.

As the Centre line values (Co-ordinates and Chainages) are computed they are stored on a user defined Horizontal Alignment File. Simultaneously, the centre line point values are displayed on the SURPAC printer emulation screen. From this screen, the output may be sent to the current Printer, to an ASCII file, or to the Clipboard.

Setting out data for Centre Line points may be computed and printed via the Setting Out Data Sheets.

The user may select to determine centre line values, or offset values on either side of the centre line. Offset lines are useful when curvilinear boundaries are required along an existing, or proposed road/rail route.

Computed Points may be :-

    Converted to a User defined SURPAC Co-ordinate File,

    Plotted on a User defined SURPAC CAD Plot Sheet,

    Combined with SURPAC Vertical Curve Data for determining Section profiles,

    Used to generate Centre Line Setting Out Field Sheets.