黄骅港淤泥动力特性的三轴试验研究

针对波浪作用的具体特点,对黄骅港海床表层淤泥进行了动模量、动变形及动强度试验。给出了该淤泥的动模量和阻尼比随固结压力和动剪应变的变化关系。通过分析该淤泥的动强度曲线发现,对于一定的固结压力对应于长振次(>1 000)的破坏动剪应力差别很小,可能存在一个门槛动剪应力,在该应力下即使长振次振动也不会发生破坏。该淤泥在波浪作用下的固结不排水剪切动强度约为静固结不排水强度的50%。

Cyclic Triaxial Test Study of Huanghua Harbor'Silt Under Ocean Wave Loading

Cyclic triaxial tests were performed to investigae the cyclic deformation behavior of the silt in the surface of Huanghua Harbor's seabed.The relationships of the change of dynamic modulus and damping ratio with cyclic shear strain amplitude were obtained,as well as undrained cyclic shear strength curve,which was expressed as the cyclic shear stress required to satisfy some failure criterion(5% axial strain)for a specific number of cycles under a certain confining stress vs.the cyclic number.From the cyclic shear strength curve it can be seen that under a certain confining stress the failure cyclic shear stress corresponding to large cyclic number is almost the same.This implies that it may exists a threshold value of cyclic shear stress,and if the cyclic shear stress is lower than it even imposing a very large number of cycles would not cause the sample to damage.The undrained cyclic shear strength of the silt is about 50% of the static undrained shear strength.