Introduction
In PVcase Ground Mount, you can perform a Collision analysis to check if your PV frames have adequate ground clearance from the terrain or fall within the specified pile reveal range.
This analysis is crucial for identifying frames that violate minimum or maximum distance constraints, helping to ensure compliance and minimize potential ground grading volumes and pile lengths.
Steps
To start working on collision analysis, open the Civil analysis menu. In the second tab, Collision & Grading, you will find the Collision analysis menu.
Here, you can:
- Define constraints for minimum and maximum ground clearance and/or pile reveal length
- Highlight frames and see detailed height of frames that don't meet the defined criteria with Indicate and Show details
- Correct the terrain beneath the frames to meet the established criteria with Grade and see the ground grading volume:
To start, select your PV area:
1. Click on Select PV areas
2. Select your PV area outline
3. Press Space or Enter on the keyboard
Similarly to the Slope analysis, you can define a range of acceptable distances between the frame and the terrain. If the value is found to be out of bounds, the software will mark the affected frame with a color designation. Since we are working with a fixed-tilt system, we are primarily interested in the Ground clearance analysis, but we will also explore the Pile reveal range option. Both options can be applied simultaneously.
Ground clearance
Ground clearance refers to the distance between the surface of the terrain and the frame, both in the front and the back of the frame:
Ground clearance analysis checks the PV frame to ensure that a given minimum and maximum clearance is respected.
In this example, the lowest permissible height is set to 0.8 meters and the maximum to 2.6m.
Once you've set the clearance, click Indicate.
If any of the frames are too low or high at some point, the entire frame will be highlighted in orange or red respectively.
Click on Show details to get further insight. Once you've selected the specific frame you want to observe, press Space or Enter on the keyboard.
PVcase places frames so that their bottom-left and bottom-right corners align with the reference height defined in the Frame and park settings (when Standard mode is used):
However, the software does not account for the terrain between these points, and there may be intermediate positions (elevations) where the frame may be lower. Terrain collision allows you to test if the placed frames have areas that extend beyond the given range.
If you zoom in on one of the affected frames, you can see that this particular point is colored orange, meaning that the clearance is less than the 0.8 meter lowest threshold.
The text in black indicates points that fall within the acceptable range.
Same for frames where our maximum height of 2.6m is exceeded in some places:
Front view
This can be best illustrated by applying a front view of the frame and measuring the distance from the frame to the terrain.
Here's how to create a Front view:
1. Open the drop-down menu next to Cross-section
2. Select Front view
3. Select the PV area boundary line when prompted
4. Draw the front view you want to create
5. Click where you want your Front view drawing to be placed.
To manually measure the frame height, go to AutoCAD's Home tab and select the measuring tool (Dimension tab). Alternatively, you can use the DIM command.
If you click on this part of the frame and draw a perpendicular line to the terrain and finish placing the dimension, you'll see that the resulting value matches the manually measured value shown in the Collision analysis.
Pile reveal range
The second option for the collision analysis is Pile reveal range. Pile reveal is the part of the pile above the terrain surface:
With Pile reveal analysis, you can specify the minimum and maximum limit for pile reveal and use the tool to highlight the affected frames and their specific poles.
First, you have to define the admissible range of both front and back poles (most often according to the criteria given by the structure supplier):
Then click on Indicate to see if the frames are in accordance with the given pile reveal range.
In this case, frames that have at least one pole that is shorter than the established lower limits, have been colored in pink. On the other hand, frames that are higher than one of the upper limits will be colored purple.
Just as with the Ground clearance, you may also go further into the Piling range analysis and inspect the calculated individual pole lengths.
To do so, click on Show Details; Ground Mount will display text labels on the frame drawing, indicating the length of each individual pole. This is similar to the Piling information feature.
To illustrate this, let's zoom in on a frame. As we can see, poles that are shorter than the Lower limit or longer than the Upper limit are marked red. Poles that are blue are within the specified tolerances and there are no issues with them.
It is also possible to combine the analysis for Ground clearance and pile reveal length by activating both check boxes. In this case, it might make sense to choose 4 different colors.
When multiple constraint violations are detected for the same frame, the coloring will be applied for the active constraints in the same order you see in the interface: clearance first, pile reveals later.
The clearance constraint is applied to both sides: front/back for fixed-tilts and east-wests.
If you want to indicate the frames out of range whenever generating a new layout without opening the Civil analysis menu, activate the Preset for generation option:
The height of the frames is unaffected by the analysis — it only serves to highlight any issues that may be present.
If, however, you would like to change frame height, change the reference height in Park settings, and then use Adapt to positions either on individual frames or the whole area:
Alternatively, instead of the Standard mode, you can use the Optimized mode.
Optimized mode
The Optimized mode works with an input range, instead of a single value. You will also see that a default setting is enabled: Minimize ground collisions.
When this mode is selected, the algorithm will fine-tune the placement of each frame so that grading collisions are minimized while keeping each frame corner within the clearance range. By doing so, the resulting layout minimizes potential grading volumes and pile lengths.
We could have used this mode when creating our initial layout. Since we have not done it in this case, we will activate it now, set our reference clearance range and then use Adapt to positions:
With the optimized mode, not all the lower corners are placed at the same height anymore, but adjacent corners still have the same height:
After having analyzed the constraints, you can perform Ground grading to modify the terrain in order to meet the set criteria.