Research On Engineering Properties And Application Of Fluvioglacial Deposits

There is plenty of fluvioglacial depodits widely distributed in area of westernChina,which has been gradually applied in the construction of embankment and subgrade ofthe highway.With the rapid development of highway,the requirement is also higher and higherfor subgrade fillers of the highway.Load-bearing characteristics,stability and deformationproblem will become the main factors in designing on subgrade of highway.The fluvioglacialdepodits coarse grained soil is widely spread along the Leshan-Yaan express way.In order toadapt to the need of engineering development,researched the characteristics of thefluvioglacial depodits coarse will have very important theoretical and practical values.Physical and mechanical properties of the fluvioglacial depodits coarse grained soil whichis distributed in Leshan region,are intensive studied by a lot of soil laboratory test.The basicproperties of the fluvioglacial depodits coarse is a research emphasis,therefore,the studies ofthis dissertation will provide theoretical references for reasonable design and construct of thesubgrade by fluvioglacial depodits.The main contents and conclusions of this dissertation include:(1) By means of water test,screening test,compaction test,CBR test,liquid and placticlimit test of the fluvioglacial depodits coarse,make sure that its road properties is as same asnormal coarse grain filler.(2) By means of large-scale triaxial test,analy the stess-strain curve and strengthcharacteristics of the fluvioglacial depodits coarse.According to the test results,the pattern ofstress-strain curve is always strain-hardening style.Mohr strength envelop of the fluvioglacialdepodits coarse is close to a straight line,the cohesion of the fluvioglacial depodits coarse is65.3kPa.(3) The applicability of Duncan E-B model to the fluvioglacial depodits coarse alsodiscussed,whether the regression results or the simulation result of the molel parameters,wecan see that Duncan E-B model is able to properly reflect the mechanical properties of thefluvioglacial depodits coarse(4) Large-scale consolidation test of the fluvioglacial depodits coarse iscarried,according to the test results,with the increase of axial stress,and the strain rate slowdown.with the increases of the vertical stress,and the compression coefficient decrease,itincrease generally with the increase of the water content.With the increase of the verticalstress,and the compression modulus increase.(5) By analysis grain breakage under the action of shear and compation,found that grainbreakage of the fluvioglacial depodits coarse appears easily under low pressure,under thesame strain,with the increase of the confining pressure,and the grain crushing rateincrease.under the same water content,the grain crushing rate of the cyclic loadin test issmaller than regular compression test.