I am an abaqus user and developer. Recently, I want to simulating the liquefaction phenomenon with abaqus/standard or abaqus/explicit. As I know, this cannot be realized using the internal program because solution of the u-p formulation is not supported. Does that mean I have to write an UEL or VUEL program to solve it ? As the postprocessing of UEL/VUEL is unconvenient, is there other simple way to solve this problem? like using umat or vumat subroutine. Any advice would be greatly appreciated.