CN1779458A - Shear-resistant strength empirical estimation for structural face of rock - Google Patents

Abstract

A method for estimating shear strength of rock mass structure surface includes setting multiple measuring sections with sampling length of 10 cm and 30 cm, measuring fluctuation range Ry10 and Ryso of profilogram, utilizing formulas to calculate out roughness coefficient JRCo and expected value E (JRCo) for 10 cm measuring section and roughness coefficient JRCso and expected E (JRCso) for 30 cm measuring section, using model of JRCo=E (JRCo)(Ln / Lo)-D to convert out roughness coefficient JRCn value of rock mass structure surface, utilizing a formula to obtain a relation curve and using tilt angle of obtained curve as shear strength parameter of said structure surface.

Description

Shear-resistant strength empirical estimation for structural face of rock

(1) technical field

The present invention relates to shear-resistant strength empirical estimation for structural face of rock, being applicable to directly provides rock mass structural plane shearing strength parameter in the evaluation of engineering rock mass Calculation on stability _PeakThe occasion of value.

(2) background technology

Before the present invention makes, prior art rock mass structural plane shearing strength parameter _PeakThe acquisition methods of value is a direct shear test method, promptly asks for rock mass structural plane shearing strength parameter by the laboratory examination or the field condition test of rock mass discontinuity sample _PeakValue, this technology comprises links such as rock mass discontinuity sampling, transportation, sample processing, test and data compilation, long in time limit, cost is high, can't consider the influence of size effect, and test findings is discrete, is not easy to the rock mass structural plane shearing strength parameter of each matter opposite sex of tool, anisotropy and heterogencity _PeakDetermining of value.

(3) summary of the invention

The objective of the invention is to solve existing test method process complexity, long in time limit, cost is high, test findings is not representative shortcoming, provide a kind of scientific and reasonable, easy to operate, speed is fast, cost is low, the shear-resistant strength empirical estimation for structural face of rock that result of use is good.

Shear-resistant strength empirical estimation for structural face of rock of the present invention comprises following sequential steps:

(1) chooses a plurality of survey sections that sample length is 10cm, 30cm on the rock mass discontinuity surface respectively along assigned direction;

(2) adopt profilograph to draw the contour curve of above-mentioned survey section;

(3) the relief intensity R of the above-mentioned contour curve of measurement _Y0, R _Y30

(4) by formula ${\mathrm{JRC}}_0=49.2114e^{\frac{29}{450}}\arctan \left[\frac{4R_{Y0}}{5}\right]$ Calculating sample length is the roughness coefficient JRC that 10cm surveys section ₀Value;

(5) be that the different roughness coefficient of 10cm survey section calculates JRC according to each sample length ₀Expectation value E (JRC ₀);

(6) by formula ${\mathrm{JRC}}_{30}=49.2114e^{\frac{29\×10}{450\×30}}\arctan \left[\frac{8R_{Y30}}{L_{30}}\right]$ Calculating sample length is the roughness coefficient JRC that 30cm surveys section ₃₀Value;

(7) be that the different roughness coefficient of 30cm survey section calculates JRC according to each sample length ₃₀Expectation value E (JRC ₃₀);

(8) according to rock mass discontinuity physical length L _n, by JRC size effect fractal model ${\mathrm{JRC}}_n=E\left({\mathrm{JRC}}_0\right){\left[\frac{L_n}{L_0}\right]}^{-D}$ Conversion rock structural plane roughness coefficient JRC _nBe worth, be the roughness coefficient value of rock mass discontinuity, wherein D is according to E (JRC ₀), E (JRC ₃₀) try to achieve;

(9) by formula

Drafting obtains σ-τ relation curve;

(10) the above-mentioned drafting pitch angle that obtains σ-τ relation curve is shear strength parameter _Peak

The present invention compared with prior art, shear-resistant strength empirical estimation for structural face of rock is scientific and reasonable, easy to operate, speed is fast, cost is low, and result of use is good, and the estimation result has embodied the size effect influence of rock mass structural plane shearing strength, for the rock mass structural plane shearing strength parameter of each matter opposite sex of quantitative statistical analysis tool, anisotropy, heterogencity and size effect provides effective means, have bigger implementary value and economic results in society.

(4) description of drawings

Fig. 1 is σ-τ relation curve

(5) embodiment

A kind of shear-resistant strength empirical estimation for structural face of rock comprises following sequential steps: to the rock mass discontinuity surface respectively sample length be a plurality of surveys section of 10cm, 30cm; Adopt profilograph to draw the contour curve of above-mentioned survey section; Measure the relief intensity R of above-mentioned contour curve _Y0, R _Y30By formula ${\mathrm{JRC}}_0=49.2114e^{\frac{29}{450}}\arctan \left[\frac{4R_{Y0}}{5}\right]$ Calculating sample length is the roughness coefficient JRC that 10cm surveys section ₀Value; According to each sample length is that the different roughness coefficient of 10cm survey section calculates JRC ₀Expectation value E (JRC ₀); By formula ${\mathrm{JRC}}_{30}=49.2114e^{\frac{29\×10}{450\×30}}\arctan \left[\frac{8R_{Y30}}{L_{30}}\right]$ Calculating sample length is the roughness coefficient JRC that 30cm surveys section ₃₀Value; According to each sample length is that the different roughness coefficient of 30cm survey section calculates JRC ₃₀Expectation value E (JRC ₃₀); According to rock mass discontinuity physical length L _n, by JRC size effect fractal model ${\mathrm{JRC}}_n=E\left({\mathrm{JRC}}_0\right){\left[\frac{L_n}{L_0}\right]}^{-D}$ Conversion rock structural plane roughness coefficient JRCn value is the roughness coefficient value of rock mass discontinuity, and wherein D is according to E (JRC ₀), E (JRC ₃₀) try to achieve; By formula Drafting obtains σ-τ relation curve; The pitch angle that above-mentioned drafting obtains σ-τ relation curve is shear strength parameter _Peak

Claims (1)

1, a kind of shear-resistant strength empirical estimation for structural face of rock is characterized in that comprising following sequential steps:

(1) to the rock mass discontinuity surface respectively sample length be a plurality of surveys section of 10cm, 30cm;

(2) adopt profilograph to draw the contour curve of above-mentioned survey section;

(3) the relief intensity R of the above-mentioned contour curve of measurement _Y0, Ry ₃₀

(4) by formula ${\mathrm{JRC}}_0={49.2114e}^{\frac{29}{450}}\arctan \left[\frac{{4R}_{Y0}}{5}\right]$ Calculating sample length is the roughness coefficient JRC that 10cm surveys section ₀Value;

(5) be that the different roughness coefficient of 10cm survey section calculates JRC according to each sample length ₀Expectation value E (JRC ₀);

(6) by formula ${\mathrm{JRC}}_{30}={49.2114e}^{\frac{29\×10}{450\×30}}\arctan \left[\frac{{8R}_{Y30}}{L_{30}}\right]$ Calculating sample length is the roughness coefficient JRC that 30cm surveys section ₃₀Value;

(7) be that the different roughness coefficient of 30cm survey section calculates JRC according to each sample length ₃₀Expectation value E (JRC ₃₀);

(8) according to rock mass discontinuity physical length L _n, by JRC size effect fractal model ${\mathrm{JRC}}_n=E\left({\mathrm{JRC}}_0\right){\left[\frac{L_n}{L_0}\right]}^{-D}$ Conversion rock structural plane roughness coefficient JRC _nBe worth, be the roughness coefficient value of rock mass discontinuity, wherein D is according to E (JRC ₀), E (JRC ₃₀) try to achieve;

(9) by formula Drafting obtains σ-τ relation curve;

(10) the above-mentioned drafting pitch angle that obtains σ-τ relation curve is shear strength parameter _Peak

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