EXPERIMENTAL STUDY OF NONLINEAR CREEP PROPERTY OF SOFT SOIL IN LITTORAL AREA
LEI Huayang1，2，JIA Yafang1，LI Xiao1
(1. Department of Civil Engineering，Tianjin University，Tianjin 300072，China；2. Key Laboratory of Coast Civil Engineering Structure and Safety of Ministry of Education，Tianjin University，Tianjin 300072，China)
Abstract：Reasonably describing creep law of coastal soft soil is very important for the long-term stability and running safety of buildings in soft soil area. By the unidirectional oedometer and improved direct shear creep apparatus，the creep tests in different loading methods are conducted. The relationships of stress，strain and time are got，the structural effect and influencing factor of creep character are also analyzed，and the relevant creep model is established. The test result indicates that the soft soil in littoral area of Tianjin has obvious nonlinear creep character and the creep evolutional characteristics are influenced by the structure. At low stress level，the creep deformation is very small，and there is an obvious transition in curve of consolidation test. At high stress level，creep rate and creep deformation are high enough. When the pre-consolidation is carried out，the creep deformation turns low and the boundary of primary consolidation and secondary consolidation is influenced. The modified logarithm function can describe the transient elastic strain，attenuation creep and steady creep of soft soil in littoral area of Tianjin. The shear creep deformation assumes double line at low stress level and linear at high stress level. Shear modulus decreases over time and increases-before-decreases with the increasing stress，coefficient of viscosity increases over time and with the increasing stress.
2013, Vol. 32 
