Experimental Study Of The Application Performance Of Improved Silty Fine Sand In Da-ma Railway

Based on a large number of investigate information about silty fine sand embankmentconstruction abroad and home， Combined with the actual situation of the geographicallocation of the Da-ta to Ma Chang-hao railway construction in-progress， Study theengineering properties of Cement improved silty fine sand as the filler of the underlying ofsubgrade bed，Based on monitoring of the test section，the deflection of the actual silty finesand roadbed are studied，And targeted for the durability of silty fine sand roadbed，Mainwork is as follows：(1) From the perspective of economic costs，the feasibility of Cement improved silty finesand as the filler of the underlying of subgrade bed is analyzed，and design the improvedprogram.(2) Based on the laboratory experiments, the physics properties and the mechanics of thecement improved silty fine sand are analyzed. Based on the heavy compaction test, thecompacting property of the cement improved silty fine sand is studied. Based on theunconfined compressive strength test, factors influencing the strength of the cement improvedsilty fine sand are analyzed. Based on compression tests, compression level for the cementimproved silty fine sand is understood. Based on triaxial compression test, shear strengthparameters of the cement improved silty fine sand is understood. Based on Wet and dry cycletest and freeze-thaw cycle test, the durability of cement improved silty fine sand areunderstood.(3) Based on the laboratory experiments, relying on engineering test section asbackground, conduct on-site monitoring of the stress-strain law of Silty fine sand Subgrade,Including the changes in the earth pressure at different locations, horizontal displacement ofSubgrade, subsidence of the whole section of the subgrade and at different depths. And withthe finite element computational method, simulate the deformation law of the model which issimilar to the silty fine sand subgrade. And then analysis the similarities and differencesbetween the field measured data and finite element simulation. Summarized the deformationlaw of silty-fine sand subgrade.(4) Based on monitoring the test section and the laboratory test, to discuss the durabilityof the Silty fine sand Subgrade, analysis the influencing factors for subgrade durability，according to the existing engineering problems then propose appropriate measures to improveits durability.