1. Geotechnical spring specification

The geotechnical spring is described in Geotechnical spring.

A detailed description of the input file is given below.

1.1. Data group identifier, one input line

GEO SPRINg SPECification

1.2. Number of geotechnical springs, one input line

NGEOSPR

  • NGEOSPR: integer > 0: Number of geotechnical springs

The following input lines are repeared NGEOSPR times.

1.3. Spring ID

SPRING-ID

  • SPRING-ID: character(8): Spring ID. Must be unique.

1.4. Spring location and properties

4 or 5 input lines, depending on the damping model selected

LINE-ID ISEG INOD

  • LINE-ID: character(8): Line identifier

  • ISEG: integer: Local segment number within line

  • INOD: integer: Local node number within segment

RLEN

  • RLEN: real, default: 0: Relative length, currently not used

FORCE1 DISP1 .... FORCEn DISPn

  • FORCE1: real: Force corresponding to DISP1. First value must be zwero. \([\mathrm {F}]\)

  • DISP1: real: Horizontal displacement corresponding to FORCE1. First value must be zwero. Values must be given in increasing order. \([\mathrm {L}]\)

  • FORCEi: real > 0: Force corresponding to DISPi. \([\mathrm {F}]\)

  • DISPi: real > DISP_i-1: Horizontal displacement corresponding to FORCEi. \([\mathrm {L}]\)

IDMP EXPDMP

  • IDMP: integer >= 0: Damping coefficient code

    • = 0: No damping

    • = 1: Constant damping coefficient

    • = N: Table with N pairs of damping coefficient / displacement to be specified.

  • EXPDMP: real >= 1.0: Exponent for displacement velocity. Dummy if IDMP = 0.

No more input for this spring if IDMP = 0

1 line of input if IDMP = 1:

DAMPGEO

  • DMPGEO: real > 0: Displacement independent damping coefficient

1 line of input with IDMP pairs of damping values if IDMP > 1:

DAMPGEO1 DISP1 ... DAMPGEOidmp DISPidmp

  • DMPGEO1: real: Damping coefficient corresponding to DISPL1

  • DISPL1: real: Horizontal displacement corresponding to damping coefficient DMPGEO1. \([\mathrm {L}]\)

  • DMPGEOi: real: Damping coefficient corresponding to DISPLi

  • DISPLi: real: Horizontal displacement corresponding to damping coefficient DMPGEOi. \([\mathrm {L}]\)

The unit of the damping coefficients depends on the value of the exponent EXPDMP. In general, the unit is \(\mathrm{F/(L/T)^{EXPDMP}}\)