Nondestructive prediction combination method for evaluating rock uniaxial compressive strength under freeze-thaw cycle

Abstract

The invention relates to a nondestructive prediction combination method for evaluating rock uniaxial compressive strength under freeze-thaw cycle. The nondestructive prediction combination method comprises the following steps: preparing a plurality of standard rock samples from a complete rock block of a rock to be tested; continuously and repeatedly carrying out freeze-thaw circulation on the plurality of standard rock samples until the standard rock samples are damaged; in the repeated freeze-thaw cycle process, after five freeze-thaw cycles are completed each time, performing a measurementprocess, and according to the mass, the longitudinal wave velocity and the porosity, calculating the limit uniaxial compressive strength of the rock to be measured by using a uniaxial compressive strength formula. According to the nondestructive prediction combination method, the porosity of the rock and the trend of the internal fracture are jointly determined through the ultrasonic technology and the nuclear magnetic resonance technology, the macroscopic integrity of the rock is controlled through the weight, the microcosmic and macroscopic structures of the rock are controlled, and prediction of the uniaxial compressive strength of the rock is more accurate.

Description

technical field [0001] The invention relates to the technical field of cracked rock damage detection, in particular to a non-destructive prediction combined method for evaluating the uniaxial compressive strength of rock under freeze-thaw cycles. Background technique [0002] Damage refers to the phenomenon that the micro-defects (such as micro-cracks and voids) of materials expand and communicate with each other under the action of load, resulting in the attenuation of its mechanical characteristic parameters, and the gradual deterioration of materials and lead to damage. It can be seen that the essence of material damage is the expansion of its internal crack system. Based on this premise, it is possible to quantitatively characterize material damage through the fracture ratio. However, due to the limitation of the test technology level, it is difficult to directly measure the rock fracture ratio. At present, the quantitative characterization methods of rock fracture rati...

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Problems solved by technology

[0004] The invention provides a non-destructive prediction combination method for evaluating the uniaxial compressive strength of rocks under freeze-thaw cycles, which solves the technical problem that the existing methods cannot accurately and non-destructively determine the strength and elastic modulus of freeze-thaw rocks, and realizes freeze-thaw cycles The non-destructive prediction of the damage strength of the lower rock makes the technical effect of predicting the uniaxial compressive strength of the rock more accurate

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