Research Of Cumulative Deformation Of Bucket Foundation Under Cyclic Load

The bucket foundation was forced to bear cyclic loads such as waves,winds,etc.The effect of these loads on the deformation is remarkable,for accumulative deformation will affect the bearing capacity of bucket foundation.It is easy to calculate the cyclic cumulative deformation by using the method of calculating creep.If the times of the cyclic vibration is analogous to the time,the cyclic accumulative deformation can be regarded as a irreversible deformation,which is similar to creep.On the basis of model tests,the time history curve of the cumulative deformation was analyzed and by theory of creep.In order to measure the cyclic deformation by a standard,the concept of neutral axis was introduced.According to the geometric principle,the data processing formula is deduced,which could be used as a standard to measure the cyclic deformation.The numerical analysis shows that the cyclic deformation increases as cyclic load proceeds,and eventually it will reach to a stable value,introduction of neutral axis was effective to correct errors and convenient for studying the relationship between different variables;The cyclic horizontal load has a significant positive effect on the cumulative deformation.The vertical static load is much less effective on promoting cumulative deformation than the cyclic horizontal load,but the vertical static load limits the effects of cyclic horizontal load.In the same load condition,the cyclic accumulative deformation.The subdivision form is effective on the influence of cumulative deformation.In the same loading condition,the cyclic accumulative deformation of subdivided bucket foundation is less than that of non-subdivided bucket foundation;the subdivided bucket foundation takes a longer period to reach the stable value.There is a maximum cyclic horizontal load for the subdivided bucket foundation and a maximum cumulative deformation for non-subdivided bucket foundation,which makes the final cyclic accumulative deformation no longer changes with the increase of the cyclic horizontal load,so it is more suitable for the subdivided bucket foundation to control the cumulative deformation.Soil pressure is the essential reason for compaction of soil,and the compaction of soil is the key reason for the development of cyclic cumulative deformation.