| In rock slope engineering, the tensile fracture of rock slope is more complicated than usual by discontinuous structure surface such as bedding and faults and joints. Currently, the determination methods of tensile strength of rock are used of the direct tensile and splitting test. As gripping and warranties tensile load axis coincides with the axis of the specimen has some difficulties, the more common method is the use of splitting (Ie Brazil test method) indirect determination of the tensile strength of the rock. The research relies on the Huaihua to the Tongdao (Huai Tong) highway project, in this layered rock slate for the study, the Brazilian splitting test as a measure, combined with theoretical analysis, it researched on the transversely isotropic rock of elastic parameters, tensile strength, failure criteria, constitutive and tensile failure and slope stability. The main results are as follows:1) Based on analysis of mineral composition, it observed the slate of cementation type and structure by electron microscopy; it tested the compressive strength and tensile strength of slate under different bedding angles by the Uniaxial and Triaxial apparatus, and it obtained strength distribution curve under the different bedding angles, it revealed the relationship between strength and bedding angles.2) It tested the rock mass of five transversely isotropic elastic parameters. It verified by compared the result of test and S-Venant empirical formula that the five transversely isotropic elastic body parameters are mutually independent, and there is no functional relationship.3) Based on the disc plane anisotropic elasticity theory, by used of Fourier series transform, it solved the anisotropy disc plane of the stress field and intensity factor and gives the anisotropic disc intensity factor expression. The expression contained five elastic parameters and bedding angle components. Analysis of the different of values of parameters on the intensity factor, it obtained intensity factor parameter curve form.4) It derived the tensile strength formula of disc change with the bedding angle (3based on weak surface theory and Heok-Brown strength criterion and combined plane stress of analytical Solution of the elastic mechanics for disc on Brazilian splitting test. The derivation of the tensile strength formula can explain the relationship of tensile strength and the bedding angle. The several failure modes of splitting test had been studied for transversely isotropic rock. When0°≤β<25.2°or72.6°＜β≤90°time, it is pure tensile failure; When25.2°≤β<72.6°time, it belong to shear failure along the level.5) Based on the elastic theory, combined with the numerical method, it studied the isotropic plate of thickness to diameter ratio, load angle and the poisson’s ratio on Brazilian splitting test. The method ever closer to actual situation, and got the reasonable of load Angle and the thickness to diameter ratio for Brazilian splitting test disc. It better realize the transverse isotropic body the application of the improved Hoek-Brown yield criterion in the Brazilian splitting test.6) Slip-cracking and dumping-cracking of layered rock slope stability against sliding of upper bound solution was deduced. Analyzed the heavy rock mass, slope height and slope foot to slip-cracking the slope of the stability, it got the curve of stability coefficient changes with the slope parameter. at the same time, it studied the failure mechanism of dumping-cracking layered rock slope, and analyzed the different parts of the steady state, and got the reasons of dumped-cracking layered rock slope. |
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