A Method for Determining the Velocity of Acoustic P-wave in Fresh Intact Rock Block

Abstract

The invention discloses a simple and convenient method for determining a longitudinal sound wave velocity value of a fresh integral rock block. The method comprises the steps of testing longitudinal sound wave velocity values of rock masses through hole drilling; analyzing changes of the longitudinal sound wave velocity values of the various lithological rock masses along with rock weathering types; performing statistical analysis on a maximum longitudinal sound wave velocity value of the various lithological fresh integral rock masses of each drilled hole, wherein it is required that the thickness of a rock stratum is greater than 1m, the number of actual measurement points of a sound wave is not less than 5, an average relative error of the longitudinal sound wave velocity values is less than 5%, and a range does not exceed 10% of an average longitudinal sound wave velocity value; and comparing the maximum longitudinal sound wave velocity value of the various lithological fresh integral rock masses of each drilled hole, and taking the maximum longitudinal sound wave velocity value of the various lithological fresh integral rock masses as the longitudinal sound wave velocity value of the fresh integral rock block. By accurately obtaining the longitudinal sound wave velocity value of the fresh integral rock block, the calculation precision of a rock mass integrity coefficient and a weathering coefficient is improved.

Description

technical field [0001] The invention relates to the quality evaluation of hydraulic engineering rock mass, in particular to a method for determining the sound wave longitudinal wave velocity value of fresh intact rock blocks. Background technique [0002] The acoustic P-wave velocity value of fresh intact rock blocks is an important parameter for calculating the integrity coefficient and weathering coefficient of rock mass. The weathering coefficient is an important parameter for the division of rock mass weathering zones and unloading zones. The rock mass integrity coefficient is an important index for evaluating the integrity of rock mass, detailed classification of underground cavern surrounding rock, and engineering geological classification of dam foundation rock mass. [0003] The current "Water Conservancy and Hydropower Engineering Geophysical Prospecting Regulations" SL326-2005, "Hydropower and Water Conservancy Engineering Geophysical Prospecting Regulations" DL / T5...

AI Technical Summary

Problems solved by technology

The main reasons are: ① After the rock blocks are taken out, the closed cracks open, the stress will be released, and even some lithological rock blocks will decompose within a few hours after being taken out; ② The rock blocks lose moisture; ③ The site does not have the conditions for processing and cutting rock blocks , resulting in unevenness at both ends of the rock block, and the planar transducer cannot be tightly coupled with the rock block, which affects the propagation of sound waves, etc.

[0005] Due to the inability to accurately determine the wave velocity of the rock mass, the calculated rock mass integrity coefficient and weathering coefficient cannot truly reflect the integrity and weathering degree of the rock mass, which in turn affects the accurate evaluation of the rock mass quality

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