Research On Long-term Deformation Properties Of Reclamation Soft Soil Under Complex Cyclic Loading

With the development of land reclamation projects,the reclamation materials gradually change from early non-sticky silt into content-based soft clay.For the different sedimentary history and formation cause,the engineering properties of these reclamation soft soils have great difference with normal soft clays.Under long-term cyclic load,reclamation soft soils will produce long-term deformation for their unique ?three high and one low? engineering properties.As more and more infrastructures were constructed on reclamation soft soil foundation,such as high-speed railways and highways,it is of theoretical significance and practical value to have a system research on the long-term deformation of reclamation soft clay under long-term cyclic loading.In this paper,a series of consolidation and secondary consolidation tests are carried out on reclamation soft soil and normal soft clay.The properties of consolidation and secondary consolidation were compared.Combined with the vacuum preloading model tests,surface-layer vacuum preloading treatment of reclamation soft soil is simulated.A series of long-term deformation tests on processed reclamation soft soil under static and dynamic loads are conducted.The deformation model of reclamation soft soil is proposed.In the model,the change and experience formula of elastic modulus EH?EK with the change of the principle stress difference is analyzed.According to the strain failure curve of soft soil,the strain damage range of reclamation soft soil is produced.It is in the range from 0.99% to 1.6%.The study finds that there is one minimum value of the deformation of reclamation soft soil with changing frequency,under the same condition.When the vibration frequency is 3Hz,the deformation of soil is the smallest.Meanwhile,the boundary value of the degradation index is influenced by vibration frequency.The combination of vibration frequency of cyclic loading has a big effect on the deformation of reclamation soft soil.Under the condition of high-frequency and lower frequency,the deformation increases obviously.