Staking linework / alignment in a surface stakeout routine

Sam Glenn

Member
I wanted to ask the question about the possibility of having the ability to stake line work or a particular alignment while also staking to a surface. This would be beneficial in so many ways.
For example… while staking a 2d line like an edge of pavement, we could get location of edge of pavement along with cut and fill at that location.
From an alignment standpoint that has 3D capability, you could be staking to the alignment and have the cut or fill to the alignment line work and also the cut or fill to the surface.
Not sure of the complexity of this task, but it would be very helpful to the construction layout guys running the LS.
 

Matt Johnson

Well-Known Member
5PLS
The easiest way to implement this would be to add a white box option that displays the cut/fill from a selected surface. This way you could stake lines and points as usual and then use the white box for the cut/fill from the surface model.
 

Michael Stazhkov

Developer
JAVAD GNSS
From an alignment standpoint that has 3D capability, you could be staking to the alignment and have the cut or fill to the alignment line work and also the cut or fill to the surface.
I want to understand your input data and workflow in different cases.
1) You have surface but also want to stake-out some lines on it. In this case you can draw 2D lines and J-Field should create this 2D lines projection to the surface and give the possibility to stake-out this complex 3D scene.
2) When you have 3D alignment and separately created surface - in this case I want to understand your input data and workflow. This is a method for defining a 3D scene. I think we should somehow treat this as single 3D scene and don't stake-out separately 3D alignment and surface. So instead of 2 Cut/Fill controls we should merge or quickly switch between this different input data if we can't merge them by some reason.
 

Shawn Billings

Shawn Billings
5PLS
This is what I propose:

We should be able to create the alignment, which would either be by import alignment from XML, create from polyline (if closed then select vertex at "zero", or by points. If by points then the user needs entry that allows for designating connections are lines or curves (circular or spiral).

Once the alignment is created, then the Objective Type is a separate interface with two main options: Station/Interval/Offset and Specify Station and Offset

For Station/Interval/Offset:
When this option is selected, then the Specify Station and Offset option is gray.

The checkboxes for Station/Interval/Offset are

Stations (Y/N) Station Interval: ______ Station Interval in Curves:______ (default is the same as Station Interval) Vertices, PC's, PT's (Y/N) Offset (Y/N) L(Y/N) Offset Distance ____ R(Y/N) Offset Distance______ Center Y/N
The user could stake stations or choose not to. If not, then the interval options would be gray. With vertices, PC's, PT's checked and stations off, then the user would stake just those vertices and the start and end of curves in the alignment. If Stations are on, but vertices, PC's and PT's are off, then the user would only stake the stations at the designated interval. Sometimes it is necessary to increase the interval in curves to better depict the curve on the ground, so a separate curve interval option is given (usually it is 2x the interval). If Offset is checked on, then the option to stake offset left, offset right, and center are given. For offset left, a specific offset distance is given. For offset right a specific offset is given. For center, there is no offset. If Offset is off, then it is assumed that the center is being staked and the options are all gray. With offsets on, the stakeout sequence would be L C R at the first station, the R C L at the second station, the L C R, alternating. The user should be able to advance to the next stake point if desired.

For Specify Station and Offset:
On the same Objective Type screen the user can specify a particular station and offset. When this objective is selected, the Station/Interval/Offset option is gray.

The Interface prompts for Station______, Offset Distance_______, Offset Direction R L

For both Objectives, a preview shows the point/points to be staked. Design points are created as the points are staked at the specified station and offset, but not until Accept/Accept As are used.

The option to get the design elevation from a selected surface should also be available.
 

Sam Glenn

Member
Shawn has a great workflow idea. Definitely more detailed and thought out than what i had envisioned.
My workflow would be like this…

Having a surface as similar to a bottom layer to work from. The finish grades of the site would be real time with cuts and fills showing in a white box. The 2D line work (curb, edge pavement, etc) could be based on station offset values or real-time stake “here” mode. The come/go would be a separate white box value. So really no different than staking to a typical alignment with vertical tied to it.
The Ability to stake to an alignment while in surface mode would be an additional white box similar to PDelta however the value that you are reading in this particular white box would be the cut or fill to that alignment (not the surface elevation) at that location (either station offset or real time).

My thoughts on why this would be beneficial to the construction layout industry is because there are multiple times when i get asked the question of what is my cover over a pipeline to the finish grade of the surface (many times the utilities are going in before site is to rough grade). This additional white box let’s me see two different elevations without having to stop the routine and get the information from an additional stakeout routine.

Another thought is having the ability to stake to multiple alignments at the same time.
Real world reason #2… i am often tasked with laying out sanitary sewer services and providing cut fill data to a proposed, parallel pipe (storm, water, etc) Having the ability to see the cut fill data of the parallel pipe in at That location where the sewer service crosses, this eliminates the requirement of having to calculate the crossing elevation or stake out the crossing once for horizontal location then leave the routine and go into a stakeout of the storm drain pipe and get the cut fill data of that current location on the parallel pipe.

I hope all of this makes sense. Let me know if i need to explain further and thank you for taking the time to understand more in depth about my request.
 

Shawn Billings

Shawn Billings
5PLS
Sam, thank you for bringing up the vertical offset for staking layers of a surface. I wrote this a couple of months ago. Also your point about seeing the difference between a vertical alignment and the surface is a good one.

For staking a surface -

Stake a Station/Offset/Elevation from Alignment/Surface
Please allow staking from a polyline/alignment for station and offset using the surface for the elevation target.

This would work in two ways:
1. User should be able to enter a station and offset to stake and the software should determine the target elevation at the entered station and offset, then user should be able to stake to the coordinate of the station/offset/surface elevation. This could be under "Alignment Points" > "Select Point". This would require the user to select an alignment, then optionally select a Surface, then enter desired Station/Offset from alignment and Vertical Offset from Surface. A preview screen would show the point on the map, then a Stake button to go to the Stake Action screen. User would use white boxes or Guide as normal to navigate to the point.

2. User should be able to move around a project and the screen should indicate the current station/offset/ and cut fill to the surface elevation at the current position of the rover. This could be under "Alignment Stake-Here". User would select and alignment, select a surface, and enter a Vertical Offset from the Surface. The current position of the rover would indicate the current station, offset, vertical difference to the surface. User could collect a point on an object and the Station/Offset and Elevation above/below the surface would be displayed.

Stake a Polyline from Alignment/Surface
Another thing that would be good is a Stake Line/Polyline from Alignment/Surface. Imagine a line that is not parallel to the centerline. This could be the edge of the road where the road is widening. So the edge is not parallel to the center, however it is still important to relate locations along this non-parallel line to the centerline. User would select an alignment, select a surface, enter a Vertical Offset from Surface, and then select a line/polyline to stake. The stake directions for left and right would be to the line/polyline to stake. The station and offset would be based on the alignment and the cut fill would be based on the surface.

Vertical Offset from the Surface
This option allows the same surface to be used for multiple levels of construction: Sub-Grade (dirt), Base (where select quality dirt/gravel is placed - perhaps divided into Sub-Base and Base), Finished Surface (top of paving). Each of these layers has a thickness. A single surface model may be used for all of them since the thickness for each layer is likely consistent. So a surface for the Sub-Grade could be used for the Finished Surface if the user knows the vertical difference between the surface and the sub-grade (1.5' for example). So the user could stake the Sub-Grade surface model with a +1.5' Vertical Offset from Surface and be able to stake the Finished Surface.

This is also useful when staking a particular feature with a required depth to the finished surface. For example, if we are putting in a cable or water line that must be 5' below the final surface, we could stake the polyline and use a Vertical Offset from Surface of -5.0' and have a cut that will keep the staked point 5 feet below the final surface. Of course if we're staking something that has a substantial height to it, such as a waterline, we'd want to enter the diameter of the pipe plus the required final depth, so it might be 5.5' for a six inch pipe.

This feature is important but also dangerous. We would want to somehow display that a Vertical Offset from Surface is being used. A user may be thinking that he is staking directly to the surface, but actually still has a Vertical Offset from Surface being applied.
 

Shawn Billings

Shawn Billings
5PLS
A good screen to have when staking a Station/Offset/Elevation from Alignment/Surface would be to show a cross-section view of the surface, the Vertical Offset from Surface, and the target Offset from the alignment and the Alignment center.

Cross Section View.JPG



I don't see a way to rotate the image on the message board, but this is a rough idea of the alternate view I'm thinking of. It shows horizontally the offset from the alignment and vertically it shows the current position, the Vertical Offset from Surface (if there is one), and the Surface. The Cut Value shows the cut to the Offset Surface indicating that an offset is applied. Perhaps the label could be "Cut 1.3 to Offset Surface (+0.5)" to indicate that a Vertical Offset from Surface of +0.5 is being applied. If there is no Vertical Offset from Surface, the label would read "Cut 1.3 to Surface".
 
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