Research On Effect Of Silt Particle Content On Dynamic Characteristics Of Saturated Silt

The Yellow River Delta is rich in oil and gas resources,is the second largest oil field in China-Shengli Oilfield and the location of Dongying City.This area is dominated by silt,and is prone to liquefaction under the action of earthquake,which can cause many kinds of geological disasters.Therefore,it is very necessary to study the dynamic characteristics of saturated silt in the Yellow River Delta,especially the liquefaction characteristics.In this paper,based on the particle composition of the silt in the Yellow River Delta,the reconstituted soil samples with different silt content were prepared.The influence of silt content,effective confining pressure and dry density on dynamic stress-strain relation,dynamic strength and pore water pressure of saturated silt was analyzed by dynamic triaxial test.Establish the calculation model of dynamic pore water pressure,the model is incorporated into the FLAC3 D program and the numerical simulation of natural saturated silt foundation is carried out.Finally,based on the dynamic pore pressure calculation model,the simplified calculation formula of dynamic settlement of saturated silt foundation is established.The main conclusions of this paper are as follows:(1)In the case of other conditions remaining unchanged,the dynamic elastic modulus of saturated silt increases with the increase of silt content,effective confining pressure and the dry density.With the increase of the dynamic strain,the effect of the silt content and dry density on the dynamic elastic modulus gradually decreases.(2)In the case of other conditions being certain and silt content of not less than 50%,the liquefaction potential of saturated siltl was decreased by the increase of silt content.The dynamic strength of saturated silt increases with the increase of silt content and effective confining pressure,and it is linear with the logarithm of initial liquefaction vibration frequency.(3)According to the test results,the calculation model of dynamic pore water pressure of the saturated silt and the related parameters are given.The numerical analysis shows that the liquefaction of natural saturated silt foundation is mainly concentrated in the middle of the foundation.The pore water pressure ratio of the foundation is gradually decreased with the increase of silt content.