AGSi Guidance / Model¶
Volume models - Worked examples¶
Geological model using surfaces - example¶
An example of a very simple geological model illustrating modelling using top/bottom surfaces is given below.
Note
In the following the JSON data is broken up in to several sections to allow commentary to be provided. The different sections join up to form the full valid JSON data. The sections taken individually may not be valid JSON data by themselves. A copy of the full valid data file can be found here.
Todo
Add link
This first section contains model metadata in the agsiModel object. In practice this would be the same for the different subsets within a model.
{
"agsiModel": [
{
"modelID": "1fb599ab-c040-408d-aba0-85b18bb506c2",
"name": "Example simple geological model",
"type": "Geological model",
"category": "Observational",
"domain": "Engineering geology",
"usageDesc": "Visualisation only",
This next part establishes the model boundary using an agsiModelBoundary object. In this case the boundary is a simple rectangular box defined by limiting coordinates and a base elevation.
"agsiModelBoundary": {
"minEasting": 12000,
"maxEasting": 13000,
"minNorthing": 5000,
"maxNorthing": 6000,
"baseElevation": -25
},
The volume model is defined as a model subset (this is optional, but good practice). This is done using an agsiModelSubset object, which is embedded within the parent agsiModel object.
"agsiModelSubset": [
{
"subsetID": "GEOL-VOL",
"description": "Geological unit volumes (from surfaces)"
}
],
Now for the elements that make up the model, in this case three geological units. Each is defined by an agsiModelElement object. The geometry for each is identified by reference to agsiGeometry objects, defined later, using the geometryID attribute.
"agsiModelElement": [
{
"elementID": "MG",
"description": "Made Ground",
"type": "Geological unit",
"subsetID": "GEOL-VOL",
"geometryForm": "Volume from surfaces",
"geometryID": "Geol-MG"
},
{
"elementID": "RTD",
"description": "Alluvium",
"type": "Geological unit",
"subsetID": "GEOL-VOL",
"geometryForm": "Volume from surfaces",
"geometryID": "Geol-ALV"
},
{
"elementID": "GCC",
"description": "Gotham City Clay",
"type": "Geological unit",
"subsetID": "GEOL-VOL",
"geometryForm": "Volume from surfaces",
"geometryID": "Geol-GCC"
}
]
}
],
The agsiModel object is now complete. We now define an agsiGeometry object as a container for the geometry objects that follow.
"agsiGeometry": {
"geometrySetID": "f402948e-d5f4-4b1c-923b-2ce8578bb5c3",
We now define the geometry objects for the geological units referred to by the relevant model element above.
Each unit is defined as an agsiGeometryVolFromSurfaces object which, in turn, reference geometry objects for top and bottom surfaces (defined in the next part).
"agsiGeometryVolFromSurfaces": [
{
"geometryID": "Geol-MG",
"topGeometryID": "Surface-Geol-MG",
"bottomGeometryID": "Surface-Geol-ALV"
},
{
"geometryID": "Geol-ALV",
"topGeometryID": "Surface-Geol-ALV",
"bottomGeometryID": "Surface-Geol-GCC"
},
{
"geometryID": "Geol-GCC",
"topGeometryID": "Surface-Geol-GCC",
"bottomGeometryID": "Model-base"
}
],
The geometry for the surfaces themselves is provided in external files. Therefore we use agsiGeometryFromFile objects to point to this data. Note that some surface are referenced twice, ie. bottom of one layer and top of another.
An exception here is the final agsiGeometryPlane object which is the bottom surface of the lowest layer for the purposes of this model, ie. bottom of model.
"agsiGeometryFromFile": [
{
"geometryID": "Surface-Geol-MG",
"description": "Top of MG",
"geometryType": "Surface",
"fileFormat": "LANDXML",
"fileFormatVersion": "LandXML-1.2",
"fileURI": "geometry/geom-geol-MG-top.xml"
},
{
"geometryID": "Surface-Geol-ALV",
"description": "Top of ALV / Bottom of MG",
"geometryType": "Surface",
"fileFormat": "LANDXML",
"fileFormatVersion": "LandXML-1.2",
"fileURI": "geometry/geom-geol-ALV-top.xml"
},
{
"geometryID": "Surface-Geol-GCC",
"description": "Top of GCC / Bottom of ALV",
"geometryType": "Surface",
"fileFormat": "LANDXML",
"fileFormatVersion": "LandXML-1.2",
"fileURI": "geometry/geom-geol-GCC-top.xml"
}
],
"agsiGeometryPlane": [
{
"geometryID": "Model-base",
"elevation": -25
}
]
}
}
Simple geotechnical design model using layers¶
Example data illustrating a simple layer model is given below.
Note
Limiting valid areas and links to data/features and some other useful attributes that would normally benefit such a model have been excluded for brevity. A copy of the full data file is included here.
Todo
Add link
This example has three horizontal layers, represented by three model elements which refer, in turn, to three agsiGeometryLayer objects.
{
"agsiModel": [
{
"modelID": "1fb599ab-c040-408d-aba0-85b18bb506c2",
"name": "Example simple geotechnical design model",
"type": "Geotechnical design",
"category": "Analytical",
"domain": "Geotechnical",
"usageDesc": "Design for some specified use case",
"agsiModelElement": [
{
"elementID": "MG",
"description": "Made Ground",
"type": "Geotechnical unit",
"geometryForm": "Layer",
"geometryID": "Vol-MG"
},
{
"elementID": "RTD",
"description": "Alluvium",
"type": "Geotechnical unit",
"geometryForm": "Layer",
"geometryID": "Vol-ALV"
},
{
"elementID": "GCC",
"description": "Gotham City Clay",
"type": "Geotechnical unit",
"geometryForm": "Layer",
"geometryID": "Vol-GCC"
}
]
}
],
"agsiGeometry": {
"geometrySetID": "f402948e-d5f4-4b1c-923b-2ce8578bb5c3",
"agsiGeometryLayer": [
{
"geometryID": "MG",
"topElevation": 22.5,
"bottomElevation": 19
},
{
"geometryID": "ALV",
"topElevation": 19,
"bottomElevation": 14.5
},
{
"geometryID": "GGC",
"topElevation": 14.5,
"bottomElevation": -20
}
]
}
}