| The land resources are in great demand owing to the increasing construction of coastal cities.Land reclamation has become one of the most important ways to develop land resources of coastal cities in China.By 2020,it has more than 1,100 square kilometers of land reclamation,which has been put into use or is about to be put into use.The creep in primary consolidation of the recently formed dredger fill foundations with no or short stress history cannot be ignored.The existing calculation methods for settlement of clay foundations do not take into account creep during the primary consolidation,which can lead to small calculation results and easily lead to engineering accidents.For example,the settlement in the dredger fill area,uneven settlement of roads and buildings,etc.It is therefore necessary to conduct a study on the primary consolidation and creep characteristics of dredger fill,and the main contents and results are as follows:(1)The primary consolidation and creep characteristics of dredger fill were investigated by GDS equipment,and the e-lgt curve and e-lg P curve were obtained,and the relationships between the compression coefficient,secondary consolidation coefficient and the consolidation stress are analyzed.(2)A one-dimensional consolidation and creep model for soft clay was developed and validated by means of numerical methods.By studying the deformation characteristics of the soil units at different depths,a real-time separation method of creep during primary consolidation is proposed.The primary consolidation and creep deformation of soil units at different depths were separated in real time to reveal the creep development law in primary consolidation,and the effects of consolidation stress and drainage path factors on creep in priamry consolidation were studied.(3)The general form of the creep model was obtained by analyzing a typical creep model,which can be written as a strain-stress-time dependent function.The influence of consolidation coefficient,secondary consolidation coefficient and drainage path on creep in primary consolidation was considered comprehensively,and the creep influence coefficient in priamry consolidation was introduced as a dimensionless parameter.A creep calculation model in primary consolidation was developed.(4)The long-term deformation calculation model of super soft soil foundation considering the coupling effect of consolidation and creep was established.The method was verified by comparing results with the FE calculations and engineering measurements. |
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