Study on Physical Parameters and Mechanical Characteristics of Tertiary Mud Stone in Baoji-Lanzhou High-speed Railway
Research purposes:Tunnel construction in expansive strata is a difficult engineering problem.Based on the expansion and groundwater test of the Beiershilipu tunnel in Baoji-Lanzhou High-speed Railway,an in-depth study of soil expansion characteristics of mud stone is conducive to determining the influence of mud stone expansion on the track deformation of tunnel and improving tunnel design theory.Research conclusions:(1)Tertiary mud stone has weak expansibility.(2)The elastic modulus,uniaxial compressive strength,uniaxial tensile strength and triaxial compressive strength of expansive rock decrease significantly after soaking,and the decreasing rates of each strength gradually decrease with the increase of soaking time.(3)The uniaxial compression tests show that the average uniaxial compressive strength decreases from 29.18 MPa to 4.65 MPa,decreasing by 84％ ,and the average elastic modulus decreases from 2.32 GPa to 0.85 GPa,decreasing by 63％ .The Brazilian splitting tests show that the average tensile strength of the expansive rock decreases from 2.66 MPa to 0.36 MPa,decreasing by 86.5％ .The triaxial compression tests show that the cohesive force of the expansive rock decreases significantly with the increase of immersion time,especially in the initial stage of immersion,from 5.82 MPa to 1.34 MPa,which decreases by 77％ .However,the internal friction angle of the expansive rock decreases,but the decrease is not large,and the total decrease is 4.07％ within 15 days of immersion.(4)The research results can provide reference for the design of railway tunnels similar to expansive mud stone.
万方数据
维普
