fracture export command

Syntax

fracture export keyword <range>

Primary keywords:

file    intersect-with-plane    property-file    template-file

Export fractures to file. By default, fractures are exported in the Itasca DFN data file format (see DFN-Related File Formats) and the ‘.dat’ extension is added to the file name if an extension is absent. FISHLab and FracMan formats are also supported. The associated fracture generation template (if unique) can be exported in a fracture generation template file, and fracture properties can be exported in a property file (see DFN-Related File Formats). These files can be imported with the fracture import command.

file s keyword

Fractures are exported to the file with name s. If no extension is provided, then the appropriate extension is added.

format keyword

Specify the format to be output. By default the Itasca format is used.

itasca

The itasca format is as specified in DFN-Related File Formats.

fishlab (3D ONLY)

The fishlab format is the flowplane format used in FISHLab with the ‘.flab’ file extension.

fracman (3D ONLY)

The fracman format follows the FracMan ASCII output format with the ‘.fab’ file extension.

intersect-with-plane <keyword> (3D only)

Specify that a 2D set of fracture traces be output corresponding with the intersection of a plane. Area intersections are not delineated. The resulting 2D DFN must be opened in a 2D Itasca program (i.e., PFC2D). The Itasca DFN data file format is used (see DFN-Related File Formats).

Note

The output intersections are centered at the location specified with the origin keyword. The \(x\)-components of the intersections are in the direction of strike of the plane, and the \(y\)-components of the intersections are in the down-dip direction of the plane.

dip f

Specify the dip of the intersection plane.

dip-direction f

Specify the dip direction of the intersection plane.

origin v

Specify the Origin of the intersection plane.

property-file s

Fracture property sets are exported to the file with name s. If no property file is exported, the corresponding property set numbers of all fractures in the exported files containing fractures are set to 1. The property file format is specified in DFN-Related File Formats.

template-file s

The corresponding fracture generation template (if unique) is exported to the file with name s, and the ‘.idt’ file extension is appended to the file name if no extension is given. The template file format is specified in DFN-Related File Formats. Note that a template file will not be exported when the intersect keyword is used.

Usage Example

The following example illustrates how the fracture export command can be used: first, to generate a DFN from a single template but with two different property sets; second, to export the DFN geometry, properties and template. 3 Files are generated:

• example.dat with the fracture geometries;
• example_prop.dat with the fracture properties; and
• example_temp.idt with the template description used to generate the fracture.

model new
model random 10000
model domain extent -5 5
;Range definition
fish define mylarge(dummy,frac)
	mylarge=0
	if fracture.area(frac)>4
		mylarge = 1
	endif
end
;Create a fracture template
fracture template create 'ex_temp' size power-law 3 size-limit 0.5 100
;Generate fractures using the template
fracture generate dfn 'example' template 'ex_temp' fracture-count 500
;Assign properties
fracture property 'jcohesion' 50 'jkn' 50e9 'jks' 5e9 range fish @mylarge
fracture property 'jcohesion' 20 'jkn' 10e9 'jks' 1e9 range fish @mylarge not
;Export the fractures, properties and templates to files
fracture export file 'example.dat' property-file 'example_prop.dat' template-file 'example_temp'
return   

The following example applies only in 3D, and illustrates how the fracture export command can be used to export a 2D cut of a 3D DFN for further analyses in a 2D code. Here, example.dat will contain the traces of the 3D DFN on the plane centered on (1,0,0) with a dip of 90° and a dip direction of 50°.

model new

model domain extent -5 5
;Range definition
fish define mylarge(dummy,frac)
	mylarge=0
	if fracture.area(frac)>1
		mylarge = 1
	endif
end
;Create a fracture generation template
fracture template create 'ex_temp' size power-law 3 size-limits 0.5 100
;Generate fractures with the template
fracture generate dfn 'example' template 'ex_temp' fracture-count 500
;Assign properties
fracture property 'jcohesion' 50 'jkn' 50e9 'jks' 5e9 range fish @mylarge
fracture property 'jcohesion' 20 'jkn' 10e9 'jks' 1e9 range fish @mylarge not
;Export intersections with the plane 
fracture export file 'example' property-file 'example_prop' intersect-with-plane dip 90 dip-direction 50 origin (1,0,0)
return   

See Also: fracture import | fracture property | fracture template create