Dynamic Triaxial Experiment Of The Influence Of Diameter And Gradation To Coastal Sandy Liquefaction

Coastal structures such as jetty destroy and collapse under wave action, the survey found sandy soil liquefaction is one of the main reasons causes damage on the coastal structures collapsed, so we should focus on coastal sandy soil liquefaction characteristics. Diameter and gradation of sand is an important factor to influence soil liquefaction, however,the research about the influence of diameter and gradation of sand to liquefaction resistance attention is less in the word, some existing research is mainly qualitative description, so it is necessary to carry out further test and theoretical research.In order to study the effect of particle size and level matching sand liquefaction characteristics, this article through to the field investigation and indoor sand particle size analysis of the Qingdao mainly six natural coast (the First Bathing Beach, the Second Bathing Beach, Shilaoren Bathing Beach, Gold Beach Bathing Beach, Yangkou Bathing Beach and Liuqinghe Bathing Beach), determine the characteristics of diameter and gradation of Qingdao coast beach, and on this basis, made into different diameter and gradation of sand sand samples.By using cyclic dynamic triaxial apparatus to simulate the wave action, with different diameter and gradation to study the sandy soil liquefaction characteristics and based on the analysis of test results of the different diameter and gradation of soil pore water pressure development regularity and development of dynamic strain characteristics, summarizes the different diameter and gradation of sand liquefaction resistance attenuation law. At the same time, the study discusses the influence on sand liquefaction characteristics of different wave cycle.Test results show that the diameter and gradation of sandy soil liquefaction resistance does have some influence, for different particle size of sand, sand particles is fine, the faster development of dynamic strain and pore water pressure, the sandy soil liquefaction resistance is poor, on the other hand, the sand particle the more thick, the slower development of dynamic strain and pore water pressure, the better the sandy soil liquefaction resistance. From the perspective of the gradation of sand particles, the content of coarse particle more sand liquefaction resistance better (the average particle size larger, more coarse particle content, bigger mean particle size) the liquefaction resistance is poorer. The longer the wave load cycles, the smaller the possibility of liquefied sandy soil.