Explosions at Christchurch's QEII stadium are part of earthquake tests and the Earthquake Commission says residents have nothing to be concerned about.
Workers are trying to establish what type of repairs are needed to the land categorised as TC3 which is suspectable to liquefaction in an earthquake.
The first of the 25 explosions will be detonated at 11.30am on Tuesday.
A siren will sound five minutes before each blast.
EQC Canterbury events manager Reid Stiven says the work is similar to explosions carried out last year at the stadium.
