Research On Deformation Behavior Of Epimetamorphic Rock And Slope Support Design Method

With the development of expressway construction in western China, a great many cutting slopes pours out. Thus the efficiency and rationality of expressway slope design becomes one of the challenges.Rely ing on expressway slopes in Guizhou,both in progress and completed,a research on support design thoery and method of weathered metamorphic slope was carried out.Through a study of microcosmic and macroscopical properties of weathered metamorphic rock, a complete deformation and strength model of intact rock and jointed rock was established,a method of failure-mode recognition stability calculationand of weathered metamorphic slope as well as a support theory were proposed. Besides,an auto-drawing and analysis computer program was developed.A tentative conclusion that mineral constituent and structure of the rock result in the anisotropy of weathered metamorphic was drawn by X-ray diffraction (XRD) and scanning electron microscopy (SEM) of rock samples.With uniaxial compression and triaxial cyclic loading tests,a research of mechanical properties of plastic deformation of rock mass and failure mechanism was carried out,finding that weathered metamorphic rock shows different elastic plastic coupling features.Based on test results, a transversely isotropic elastic-plastic theory considering elastic-plastic coupling and non-associated flow rule was established.Through complete mechanical properties test of rock and statistical analysis of rock joints geometry and mechanical parameters, a contimuous medium model of rock mass was established and elastic constitutive relation of transversely isotropic layered rock mass was analized.Deformation parameters of equivalent continuum model of the rock mass were estimated according to laboratory test result of rock and in-situ test result of weak structural plane of rock mass.Combined with Xiamen to Chengdu expressway construction, a method of failuer modes recognition was proposed and corresponding anlysis programs were developed through statistic analysis of structure surface's key elements, experiments and back analysis of rock mechanics parameters. Towards cable anchor and anchor frame beam, the most common slope-support style in Guizhou, corresponding support calculation models and formulas were proposed respectively as well as targeted consolidation and protection scheme.Using ActiveX,Office,AutoCAD interface was realized with construction documents generated automatically.It's of great guiding significance, obvious social,economic and environmental benefits to similar designing and reinforcement engineering of slopes,even future expressway slopes in mountain area.