Abstract: This disclosure relates to the integrity of a civil structure, and in particular the assessment of the integrity of one or more joints of a civil structure. Two or more sensors (200a) and (200b) are provided on different substructures (102) and (106) that form the structural joint (112), wherein each sensor (200a) and (200b) generates sensor data associated with the substructure that that sensor is provided on. A measure of similarity is determined between the sensor data. The integrity measure of the structural joint is based on the measure of similarity. The method exploits the finding that when a joint is stressed and healthy (and inturn has good structural integrity), sensed movement of each substructure that forms the joint is substantially similar, such as in frequency or amplitude. Other aspects of the invention include software and a computer implemented method.