Physical and Mechanical Properties of Cement Sandy Gravel Material Research and Finite Element Analysis
|School||Xinjiang Agricultural University|
|Course||Water Resources and Hydropower Engineering|
|Keywords||cementitious sand and gravel dam mixture ratio mechanical properties triaxial tests finiteelement analysis|
Cementitious sand and gravel dam referred to as CSG dam, dam material is in the gravel stone andwater mixed with a certain amount of cement materials simple mixing of Cementitious sand and gravelmaterials, this material has many advantages that widely drawn materials, low cost etc. Basic section of thedesign of dam is symmetrical isosceles trapezoid on upstream and downstream, the slope ratio scopebetween1:0.5and1:1, the dam control seepage on the upstream panel, simultaneously, it has concrete facerockfill dam and concrete gravity dam type, the advantages of it has the very good safe reliability andeconomical efficiency, at the same time, it also known as "pollution-free dam", it has great competitive andapplication prospect.In this paper, the research results that basis on the summarizing of domestic and overseas, the systemresearch of cementitious sand and gravel material related physical and mechanical properties test and finiteelement analysis, obtain the following conclusions:(1) Through the three factors and five levels orthogonal test, using the range analysis and projectionpursuit regression analysis, the Cementitious sand and gravel material of influence weight of compressivestrength is amount of gel, water-binder ratio and fines content; The more amount of gel, the greatercompressive strength of material, the best water-binder ratio is1.2and when the fines content at25%~30%, the maximum compressive strength of material; The optimal mixing ratio for the gel dosage is60kg/m3, fines content is30%and water-binder ratio is1.2.(2) Gelling of sandy gravel material increased with the prolongation of the compressive strength anddecreases with the increase of silt content by the ages, silt content and size effect test, when the silt contentis more than5%, the compressive strength obviously decreased; Specimen size is250mm and maximumdiameter is80mm is less than the compressive strength of the specimen size is150mm and maximumdiameter of40mm of compressive strength.(3) According to the experimental research for the optimal mixing proportion get material Poisson’sratio is0.21, the uniaxial compressive strength is1.43MPa, the elastic modulus is7133MPa, thecoefficient of permeability at10-4orders of magnitude, between concrete and gravel stone material, itsmechanical properties is closer to the concrete.(4) The material is obtained by the scale triaxial tests of the stress-strain curve is linear, nonlinear andsoften the three stages, the strength of the material is obviously affected by confining pressure with theincrease of confining pressure and the destruction of the material strength also increase; In volumetricstrain and axial strain the relationship curve of the shear shrinkage after dilatancy characteristics; Materialof cohesive force and internal friction angle change with the material stress state, and has greatanti-shearing strength.(5) To formulate three different slope ratio that using ABAQUS two-dimensional finite elementanalysis was carried out on the cementitious sand and gravel dam, the dam is calculated in the completionperiod and storage period of displacement, stress, strain and stress level changed laws, namely all increasewith the increase of the slope ratio; And emphatically analyzes the slope ratio is1:0.65dam body size anddistribution of the stress and strain, comparative analysis is made of the advantages of gelled gravel dam,provide a reference basis for engineering design.