When editing alignments, or other control lines, some thought needs to given to the consequences of editing these objects. The following scenarios show the cause and effect of such actions.
Turning a primary alignment into a secondary alignment:
The chainage equations, section markers and the corridor of interest will be deleted as these are not supported by secondary alignments;
The cross section sets will be deleted as these are dependent upon the section markers;
The long sections will remain, but their chainages will be updated to reflect the chainages of the primary alignment as secondary alignments get their chainages from their primary alignment.
Turning a secondary alignment into a primary alignment:
The long sections will remain, but their chainages will be updated so that they no longer reflect the chainages of the primary alignment it was related to.
Changing the horizontal geometry of a primary alignment:
The distances and chainages will be updated to reflect any change in length;
Chainage equations will be deleted if the key points they are attached to have been deleted;
Fixed section markers will stay attached to the key points, or they will be deleted if the key point has been deleted;
Floating section markers will reposition themselves by distance along the alignment. Any section markers, whose distance exceeds the length of the alignment, will be deleted;
A freehand corridor of interest will not change;
A table corridor of interest will update itself based upon the distances in the table. Any table distances beyond the end of the alignment will be deleted;
Cross sections will be assessed individually on what has happened to the section marker it is attached to. If the section marker has been deleted, moved, or the orientation changed, the cross section will be deleted from the set. If all individual cross sections are deleted the set will be deleted. If a cross section has not moved, but its distance or chainage have altered, it will be updated to reflect the new values;
Long sections will be assessed based upon changes to the underlying horizontal geometry of the primary alignment. If it can be determined that the underlying horizontal geometry has not changed, it will maintain that portion of the long section. This may result in holes, or shortening of the long section. Distances and chainages along the long section will also be updated;
Secondary alignments to the primary alignment, and long sections along the secondary alignment, will have their chainages updated.
Changing the horizontal geometry of a secondary alignment:
Distances will be updated to reflect any change in length and the chainages based on the primary alignment will be recomputed;
Long sections will be assessed based upon changes to the underlying horizontal geometry of the secondary alignment. If it can be determined that the underlying horizontal geometry has not changed, it will maintain that portion of the long section. This may result in holes, or shortening of the long section. Distances and chainages along the long section will also be updated.
Changing the horizontal geometry of a line with long sections:
Long sections will be assessed based upon changes to the underlying horizontal geometry of the line. If it can be determined that the underlying horizontal geometry has not changed, it will maintain that portion of the long section. This may result in holes, or shortening of the long section. Distances along the long section will also be updated.
Changing the horizontal geometry of point range or two point control lines:
This will have no effect upon any long sections generated along these control lines. As these control lines are not true line objects in the data base, it is not possible to monitor changes to the relationships between these points. These types of long sections are considered to be snap shots at the time of creation and as such, it is the user's responsibility to be aware of any changes that have been made which would affect these long sections. If the user requires the system to monitor changes to these long sections it is necessary to create a line or alignment passing through the required points before generating the long sections.