Field disturbance of structured clay and its effect on settlements of soil foundation

Natural soil was prone to be disturbed.The structural strength consequently was reduced and the engineering properties changed.The field disturbance during construction,such as the installing of vertical drain,was distinct from the sample disturbance.Based on the mechanism of field disturbance,a new method for modifying the compression curve of disturbed soil was developed.Then,the evaluation of the field disturbance degree was discussed associated with the results of the vane test in situ.Furthermore,the additional settlement due to the field disturbance and the compression behavior of disturbed soil were analyzed considering the varied structural strength with depth and varied compressibility during the process of loading.The computed results of typical examples indicated that settlements due to field disturbance could be predicted by the proposed method and the field disturbance had a significant influence on the compressibility of natural soils,which should be emphasized in practice.