黄河冲积粉土动三轴试验与动力特性研究

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中图分类号：TU411文献标志码：A

Abstract：To research dynamic characteristics of saturated Yellow River aluvial siltunder cyclic loading，a dynamic triaxial testof silt in aconstruction site near Jinan sectionof theYelow River wascarriedout byusing ahydraulically controlleddynamic triaxial test system.Taking relativedensity and cyclic stress rateasvariables，development laws of pore water pressure ratio，axial strain， stress -- strain，and dynamic strength of saturated Yellow River alluvial silt samples under cyclic loading wereanalyzed.The results showthat growth modes of pore water pressre ratio timehistory curves of soil samples during vibration are early sudden increase modes，and growth modes of axial strain time history curves are single strain growth modes.Growth rates of pore water pressure ratio time history curves and axial strain time history curves of soil samples under vibrationloadare greatlyafectedbyrelative densityand cyclic stressrate.Whentherelative densityislargerandthecyclicstressrate issmaler，thesoilsamplesarelesslikelytobeliquefied.Hystereticloopsare generated in the processof vibration loadingof soil samples，and the number of hysteretic loops increaseswith the increaseofrelativedensity.Intheinitial stageofvibration，hystereticloopsareconcentratedand theareadiferenceis small.With the increase of loading times，transverse waveforms of stress-strain curves change more and more，and he energydissipationof soil samples inthe processof vibration shows atrendof stable inearlystage，rising inmiddle stage， anddecreasing in later stage.The dynamic strength of soilsamples is related totherelativedensityandthecyclic stress rate.The dynamic strength curves are similar to polylines，and graduallshift upwardwiththe increaseof relative density. Keywords： laboratory soil test；dynamic strength;theYelow River alluvial silt；dynamic triaxial test；axial strain；pore water pressure ratio

土体在振动荷载作用下发生液化导致孔隙水压力增大，有效应力减小，从而导致地面沉陷、建筑物倒塌、地下结构破坏等事故发生[1-3]，给人们的生命财产安全带来严重的损失。（剩余7347字）