Journal of Cold Regions Engineering

The horizontal earthquake‐induced hydrodynamic pressure acting on the surface of axisymmetric offshore and coastal structures constructed in the freeze area is explored by a special semianalytical and seminumerical approach. The seawater is considered as inviscid and compressible, and the motion of the water is limited to small amplitudes during an earthquake. The surface of the seawater is assumed to be covered by a floating broken ice layer. The numerical examples are presented to illustrate the results obtained from this method. Accuracy of numerical computation is discussed in the paper. Results are provided for the rigid structures with sloping surface and sharp corners in the condition that water surface is covered by a floating ice layer. Attention is given to the effects of the floating ice layer on vertical distribution of the hydrodynamic pressure. The influence of ice layer to the frequency response of hydrodynamic pressure is investigated. The effects of geometrical shape of the structural surface on hydrodynamic pressure and the application of the proposed method to typical offshore structures subject to base motion are also discussed.

Creep tests were conducted on a fine‐grained frozen soil at different salinities ranging from 0 to 20 ppt (parts per thousand), at temperatures between −5°C and −17°C and at two total water contents of around 34% and 52%. The test results indicated that the presence of salinity in the pore water considerably increases the creep strain rates of the frozen soil. This type of behavior is more prominent under high creep‐stress conditions. Unique relationships are found to exist between secondary strain rate and time, initial strain rate and relative creep load (creep stress to peak strength ratio), and initial strain and relative creep load. The relationships developed are not affected by the different salinity, temperature, and total water content conditions of the frozen soil. Similar creep behavior was observed when the frozen soil was subjected to similar relative creep loads under various temperature and salinity conditions. The results obtained in this study suggest a possible way of generalizing the creep characteristics of a frozen soil subjected to changing salinities and temperatures.