| For the upper soft and lower hard double layer soft clay foundation land reclamation works of coastal area in Tianjin,complicated physical properties and engineering characteristics often make buildings appear many engineering problems.However,so far the consolidation deformation mechanism of soft clay double foundation is deficient,and the theory is behind the practice.It is necessary to study the consolidation properties of soft clay double foundation.Using the modified oedometer,this paper studied on the behaviors of consolidation with different water contents and soil relative thickness of dredger soft double foundation.The main conclusions consist of:(1)The final stable deformation of bilayer specimen and upper soft increases along with moisture content;Load increasing to a certain extent,the impact of moisture content on soil deformation will gradually decrease.On the basis of the test data,to consider the vertical effective stress and the moisture content,the upper soft and the lower the soil were established hyperbolic compression model.(2)The final stable deformation increases along with the increasing of thickness of the homogeneous sample and thickness ratio of bilayer specimen.Double foundation thickness ratio increasing to a certain extent,the impact on soil deformation will gradually decrease.On the basis of Mitchell’ strain rate and time double logarithmic curve,a one-dimensional consolidation strain experience model was proposed,simulating deformation characteristics of double ground.(3)When surcharge preloading duration is longer than primary consolidation time,the foundation deformation and secondary consolidation coefficient significantly reduces after removing the overload.For the upper soft and lower hard double layer soft clay foundation land reclamation works of coastal area in Tianjin,the suitable surcharge ratio is 0.5 or less and the best surcharge preloading duration should be controlled in 1 to 3 times the primary consolidation time. |
PDF Full Text Request