Test Research On The Dynamic Ability Of Silty Soil

In the earlier period, a lot of attention has been paid on the sand liquefaction. Most of research on the liquefaction phenomenon had been done on the estimation of resisting force and remnant strength of pure sand when liquefaction triggers, while it is not enough for the research on the dynamic property of saturated silty soil under earthquake action. After Haicheng and Tangshan Earthquake in China, the liquefaction of silty soil has caused researcher's attention too. By triaxial test and shaking table test, the essay focuses on study of the liquefaction of silty soil, and gets some interesting results. The main content is as follows: ( 1 ) A brief summery is made about the development of earthquake liquefaction on sand and silty soil , and also distinguishing methods to it is generally elaborated。Although some results on the liquefaction of silty soil has been gotten, there are many problems as the liquefaction of silty soil is little rare. (2)Based on the dynamic triaxial test, some research on the liquefaction resisting force of silty soil has been done. The results briefly explore the relationship between fines content and the liquefaction resisting force of silty soil, and also point out that liquefaction resisting force is not monotonously changed with fines content, instead, when the content reaches certain amount, the liquefaction resisting force will reach its lowest. For the kind of silty soil in this essay, the liquefaction resisting force will be at its lowest when the fines content is up to 50%. ( 3 ) According to the theory of similitude law, some liquefaction test has been done on shaking table to analyze the liquefy ability of the silty soil. Some audio-visual experience on the procedure of silty soil liquefaction and soil damage after liquefaction is acquired. The test results indicate that when the density of silty soil is comparatively low, the whole saturated silty soil layers in the model case may be liquefied. (4)Based on the results from dynamic triaxial test, firstly, some research has been done on the increasing regularity of pore water pressure and permanent tendency of saturated silty soil, and some mathematic models have been built correspondingly. Then old and newly-built model are adopted respectively to analyze the increasing regularity of pore water pressure and strain. Finally, the newly-built model is added into a finite element method program. Combining with conditions of large shaking table test, dynamic analysis has been made. Through computation, the result is in accordance with that of the large shaking table test, and it proves the accuracy of conclusion got form the test early days.