The effects of shearing strain rate on mechanical behavior of Zhanjiang strong structured clay have been investigated systematically by means of triaxial test.It is discovered that the strong structured clay has special mechanical effect of shearing strain rate;and the CU shear strength increases at first then decreases with the increase of strain rate

and a critical rate exists.The effect of strain rate on pore pressure is not so significant under the low confining pressure condition

whereas with the increase of confining pressure

the effect gradually becomes significant.Furthermore

the cohesion and internal friction angle entirely decreases and increases with the increase of strain rate

respectively

which show turning points when the strain rate increases to a certain value

but the latter lags behind to the former.The above-mentioned phenomena are resulted from the breakage behavior of clay structure related to the strong and weak structure of soil

which provides a help to understand the engineering properties of structured clay further.