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 \(\mathrm{F/(L/T)^{EXPDMP}}\) Geotechnical spring Soil layer profile