Study On Cyclic Softening Characteristics Of Coastal Structural Soft Soil

There are structural softness of natural soft clay.There are some inconsistencies in the experimental results and engineering construction of undisturbed soil and remolded soil.In this paper,the dynamic triaxial and hollow torsional shear tests are carried out for the structural properties of coastal structural undisturbed soil.Based on the test results,the cyclic softening characteristics were studied,and the results of the two experiments were simply compared.Finally,the empirical model was established and compared based on the dynamic triaxial experimental data.(1)Due to the structural nature of the soil,the key preparation technology of the soft clay sample was improved.Three different specifications of the drill were used to drill holes in succession.The original hollow cylindrical sample was successfully prepared,and the soil was sampled during the preparation process.The sample disturbance is small,that is,the structurality of the sample is ensured,and the inner and outer walls of the sample are ensured to be smooth,which can well meet the indoor test requirements and ensure the uniformity of the test results.(2)The undrained cyclic triaxial test of saturated soft clay in Zij ingang,Hangzhou was carried out by GDS dynamic triaxial apparatus.The dynamic stress-strain and pore pressure of saturated soft clay were discussed systematically by cyclic stress ratio,vibration frequency and effective confining pressure,cumulative strain,cyclic softening and other indicators,and a reasonable analysis of the test results.(3)The undrained cyclic triaxial test of Hangzhou Zijingang soft clay was carried out by GCTS hollow torsion shearing instrument to study the dynamic stress-strain,pore pressure,cumulative strain of saturated soft clay,such as principal stress deflection,cyclic stress ratio and vibration frequency.The effects of cyclic softening and other indicators were analyzed,and the test results were analyzed reasonably.The results of dynamic triaxial and hollow torsional shear tests were compared and analyzed.(4)According to the existing pore pressure,softening index and strain model,combined with the dynamic triaxial test data,the empirical model of cumulative pore pressure,softening index and cumulative axial strain is obtained by fitting the model to the construction.Suggest.Figure 105 table 5 references 106...