The Experimental Research On The Characteristics Of Hydraulic Fill In Tinjin Binhai New Area Under The Principal Stress Axis Rotation

Tianjin Binhai New Area, located in the center of Tianjin coastaleconomic circle, In the broad Tianjin Binhai coast deposit richsediment resources. Binhai New Area is typical paralic-coastalsedimentary soft soil area. In Tianjin hydraulically-filled soft soil onsuch a large scale traffic engineering, how to reasonably evaluate thesoil traits change under dynamic loads, it is bound to become the keyproblem to be solved of these important projects concerned withinternational people’s livelihood in the survey, design, construction,and other aspects. Aiming at these problems, on the basis of previousstudies, through indoor experiment method, take the soft dredger soil ofTianjin Binhan New Area as the test materials, GCTS hollow cylinderapparatus of Tianjin Insitute of Urban Construction as a platform tostudy the test characteristics under the dynamic load. The maincontents and results are as follows:Application of GCTS hollow cylinder apparatus of TianjinInstitute of Urban Construction, take soft dredger soil of Tianjin as theresearch object to conduct the principal stress axes unidirectionalrotating directional shear and rotation of principal stress axes of sheartest. By experiment on the change of pore pressure development, shearstrength and stress-strain relationship of major conclusion:(1) through Kelvin equation in considering the main stress theoryof pore pressure analysis. Analysis the date of the principal stress axisdirectional shear measured pore pressure, draw the pore pressure andshear stress (U-q) curve, and give the explanation of the developmentrule of soil from the microscopic mechanism and soil anisotropic angles.Application of orange software simulate pore pressure under the principal stress axes directional shear, put forward development of porepressure model; and gives a detailed analysis on the model parameter ofpore pressure development feature.(2) Based on the analysis of the pore pressure failure criterion andthe ultimate failure of standard, ultimately determine the ultimatefailure criteria as for the soil sample failure criterion, and wouldundermine the standard generalized shear strain to express, whose valueis determined as6.5%.(3) Plotted normalized shear strength graph and the measuredshear strength stable, combined with affecting the shear strength:analyzed the law of their impact on the shear strength from twoinfluence factors on rotation angle of principal stress and principalstress coefficient.(4) By drawing a curve to analyze the relationship between stressand strain of hollow cylindrical specimens.