After obtaining ground characteristics from laboratory and field experi-

ments, it is necessary to calculate the primary and secondary stresses in the

ground, in order to assess the stability of the ground and likely loading on

the tunnel lining. This will aid the selection of a suitable tunnelling method,

assess whether ground improvement methods are necessary as well as

provide the input parameters for preliminary analysis and modelling of the

tunnel. This chapter focuses on obtaining the additional information,

especially in soft ground, as well as the preliminary analysis techniques that

may be employed.