Most natural clays have structural property

so the disturbance of foundation treatment changes engineering property of soft clay ground. Upper and lower limits of compression and settlement characteristics of structured soft clay are analyzed by comparing in-situ compression curve of disturbed soft clay with its experiment curve. Soft clay settlement calculation formula considering influence of disturbance is presented. The examples show that the construction disturbance enlarges settlement of structured soft clay ground between initial void ratio e0 and void ratio 0.42e0. Additional settlement is related to stress level and disturbance degree

whose value is in the range from 0.1 to 0.3 under the general stress level. The influence of disturbance becomes negligible with the increase of stress level finally. Relational conclusions are used for the project.