Trimble Business Center

 View Only
Expand all | Collapse all

How can you draft projected surfaces as cross sections?

  • 1.  How can you draft projected surfaces as cross sections?

    Posted 06-04-2019 11:12

    Hi,

     

    I'm working on a project where we are having to periodically measure the vertical face of several H-piles along a lag wall to try and see how much the wall itself is shifting. I want to be able to plot these measurements out in the same way that I would a roadway cross section. I've made several projected surfaces, but these don't show up in a cross section view. I've also tried the cutting plane view, but that doesn't give me any alignment data. I've ran cut/fill maps between my surfaces which is nice, but I'm looking for a way to display each pile vertically in a PDF against a reference surface or alignment for the planned face of wall.

     

    Any Ideas? 



  • 2.  Re: How can you draft projected surfaces as cross sections?

    Posted 06-05-2019 08:07

    Brandon

     

    You are right that the Projected Surface will not easily at least allow you to do that - I would use the Radial Surface Model which is a Corridor to do what you are trying to achieve - there are a few tricks to that and I have I believe posted videos on that in the past (and have them that I could share) but it will let you build a Corridor Model of the Radial Surface that you can plot out to Cross Sections.

     

    If you need help or want me to look at this and generate you an example, you can send me access to the file I can take a look today for you (just share a VCL of the Source Data and any related alignment (or draw an alignment to which you want the cross sections cut perpendicularly, and if you want sections at specific stations let me know where you want them.

     

    You can email me the data to alan_sharp@trimble.com if you want to keep it private and confidential

     

    I will take a look at Projected Surface again today to see if there is any way that we can produce a Section or Profile - e can maybe do it by drawing section lines and then changing the elevation of the lines using the Projected surface - however some things in that area are restricted at this time because of the way the projected surface works

     

    Your need is to create a Section / Profile perpendicular to the surface face at specific locations - right?

     

    Alan

     

    Alan



  • 3.  Re: How can you draft projected surfaces as cross sections?

    Posted 06-05-2019 13:35

                   Thanks Alan, I've sent you a link to the data via email. It'd be awesome if you'd be able to use it to generate an example using our data

     

                    I’m basically looking to display a vertical cross section type of view at the locations where shots were taken on the face of the piles. I need to display that information graphically against a reference alignment or surface that represents the true “planned” locations against the pile’s original location and it's movement over time. There's an example of what I'm trying to accomplish in a PDF file that I made -  it's in there with the link.

     

     

    Thanks.



  • 4.  Re: How can you draft projected surfaces as cross sections?

    Posted 06-07-2019 11:22

    Brandon

    I am just posting the dialog that we had via email here (in a general sense) for the benefit of others that may have similar types of work that could use the same work flow. I will be posting the video on here shortly (once it finishes compiling).

     

    Here are my Process Steps that I used to create the Cross Section Drawings that I show below here

    1) I created a Design Back of wall face - I had to offset the toe of the wall by 0.01' so the wall back was not vertical
    2) I created a polyline along the Back of wall alignment and then offset that polyline 25' to the Right to give me a baseline for the Radial Surface
    3) I added 50' Fillet Radii to the two PIs on the horizontal because the Radial Surface needs a curvilinear alignment with tangential segment end points - I set the vertical to Elevation 720 for the entire length - this is not that critical
    4) I created a radial Surface of all the Point Cloud Data using a Vertical Offset of 6' (assumed instrument height) and an approximate  Radius of 30' - this is just used to compute the triangulation of the radial surface (uses a Tunnel type technique) - Note when creating a Radial Surface I typically create the surface without adding data (especially point cloud data), and then edit the settings for the Approximate Radius and the Edge Length of triangles (30' and 10' in this case, and set the Unwrap From Top property to Yes. Once I have the properties as I need them I add the Point Cloud to the surface model using Add / Remove Surface Members. 
    5) I created a Corridor and referenced the Wall Design as a Reference Surface and added the Radial Surface as a surface instruction - the corridor uses my 25' offset alignment
    6) To get the piles to show up in each cross section I had to generate a surface for each pile - in some cases I had to generate two surfaces because the Piles kink in the middle - so I broke the piles at the kink points and made a Top and Bottom surface (called Pile X - Surface 1a and 1b etc.). To create the pile surfaces I copied and then moved the copy of each pile up and down station by 1' maintaining the offset of the base of the pile - then added the three pile lines to a surface
    7) I added all the Pile surfaces to my corridor as Reference surfaces so I can plot them in the cross sections. The cross section slices the Pile Surfaces which gives me a Projected section of the pile face at each cross section. I did not do all the piles at each location but I did most of them.
    8) I then imported my Big Sheet Drafting Template (posted previously on the forum here) and played with the settings to get the cross sections in a form that looked OK - I used a fractional Vertical exaggeration (e.g. 0.5) to expand the horizontal separation of the different surfaces - you can see the settings I used in the Edit Cross Sections (of the Plan Set).
    9) I then Built the Plan Set Sheet to get the section drawings.
    10) because the sections are computed from my 25' offset alignment 0- the stations were off so I edited the text of the sections to reflect the stations in your PDF file and also the Titles
    11) I then exported the 4 sections to DWG file by selecting just the sections in the sheet view.
    12)I then imported the sections into the Plan View of the Project. I then scaled them from 0,0  by 100 to make them larger
    13) Finally I moved them into the position near the wall model in the Plan View so you can see them. The sections are fully editable - they are just linework now so you can draw on other things and label them up as you see fit - you may want to scale them to label them or measure and compute the real values by reversing out the scale and then drawing Text on the drawings.
    14) once in the Plan View you can re-scale them using Scale XY in the Scale Command and get them to a 1:1 scale. Then you can use Dimension Labels etc to label up the offsets as per your diagrams you shared. Once dimensions have been applied, you can re-scale the sections to re-exaggerate the horizontal separation of the lines etc.
    15) Once you have the drawings as you want them - you can lay them out on a Drawing Sheet using Dynaviews etc as you see fit, use Plot Box and Print or output them to a DWG or PDF File etc as needed.
    I learnt a fair bit from this process - the process works and I get the result you were ;looking for, but this highlighted quite a few areas that we could improve, however I think this is repeatable and you can get out of this what you need. The Video tomorrow will give you a little more detail on each of the steps above.
    Thanks for raising the question and sharing your information - I hope that this helps
    Let me know if I can assist further in any way - great to meet you (at least virtually) and I look forward to helping you again in the future as needed.
    Here is the Video (coming shortly - beak out the Popcorn!)
    Alan


  • 5.  Re: How can you draft projected surfaces as cross sections?

    Posted 06-10-2019 14:51

    That looks great Alan, thank you. I'm definitely going to give this a try with further measurements on this project. It seems to me like it might be much easier for us to scan every time versus trying to take individual measurements on the piles. That might eliminate having to make so many surfaces at each of the pile locations. I will follow up if I have any questions when I attempt to do this. Thanks again!



  • 6.  Re: How can you draft projected surfaces as cross sections?

    Posted 06-10-2019 14:52

    No problem - thanks for the feedback - much appreciated

     

    Alan

     

    On Mon, Jun 10, 2019 at 3:51 PM BrandonTobias@amesco.com <trimble@jiveon.com>



  • 7.  Re: How can you draft projected surfaces as cross sections?

    Posted 02-09-2020 18:58

    Hi @Alan Sharp,

     

    I remember your exercise on Radial Surfaces at the Melbourne PUG 2019.

     

    I am having a little trouble creating a 'dummy' alignment to produce the surface.

    If you take the Rockface example we used how would you create a quick alignment to create the radial surface?

     

    I tried digitising a 3D linestring to a pointcloud, then Create Alignment based on this but did not create a surface.

    Instead a blue flag raised saying 'some points could not be projected onto the alignment'.

     

    Any help would be great

     

    Thanks

     

    Gareth



  • 8.  Re: How can you draft projected surfaces as cross sections?

    Posted 02-10-2020 00:21

    It has to be a curvilinear alignment without breaks at the tangent points - so use the HAL editor or you can use a Polyline frame and then use the fillet command to fit arcs and then make sure the polyline is connected up and then create the alignment from that polyline.

     

    The alignment has to extend beyond the limits of the Point data that you want to make the surface from - ie if you draw a perp line from the endpoints of the alignment there cannot be any points in the point cloud beyond that.

     

    Once you have the surface - add it to a corridor and you can cut sections on the corridor model

     

     

    Alan

     

    Sent from my iPhone



  • 9.  Re: How can you draft projected surfaces as cross sections?

    Posted 02-11-2020 20:14

    Thanks Alan,

     

    Got something to work, my workflow was:

     

    1. Create a linestring and used tangent arc as the type - is this the best option?
    2. Created an alignment - left spiral type as Clothoid. Does this make a difference for this application?
    3. Created a radial surface using the above alignment - I nominated the vertical offset at 10m as total bench height about 20m. Correct?
    4. After created changed surface properties 'Unwrap from Top' to yes which seems to work best for pit/canyon surfaces

     

    Cheers

     

    Gareth



  • 10.  Re: How can you draft projected surfaces as cross sections?

    Posted 02-11-2020 23:37

    Alignment, plotline and filler the corners or linestring works and then convert to an alignment - just make sure that all the change points are truly curvilinear and have no deflections

     

    Alan