CN1815183A - Evaluation method for representitiveness of rock structural fece sample - Google Patents

Abstract

Present invention relates to a rock mass structure surface test sample representativity evaluation method. It includes following steps: calibrating test direction respectively on selected rock mass structure surface test sample and in situ rock mass structure surface to make rock mass structure surface test sample direction concordance with in situ rock mass structure surface roughness coefficient measurement, to proceed orient statistics measuring to rock mass structure surface test sample according to calibrating direction to obtain rock mass structure surface test sample roughness coefficient eigenvalue JRC 0, uniformly distributing not less than 30 strip measuring line along calibrating direction according to rock mass structure surface test sample length, to proceed orient statistics measuring to obtain sample size in situ rock mass structure surface roughness coefficient eigenvalue JRC 0 * evaluating structural plane test sample representativity by k=|JRC 0-JRC 0 * |/JRC 0 *. If K=0-0.15, means fine structural plane test sample representativity, if K=0.15-0.4, means better structural plane test sample representativity, if K=0.4-0.7, means intermediate structural plane test sample representativity, if K=0.7-1, means bad structural plane test sample representativity, if K>=1, means very bad structural plane test sample representativity.

Description

The representative evaluation method of rock mass discontinuity sample

(1) technical field

The present invention relates to direct shear test structural plane typical sample evaluation method, be applicable to that the rock mass discontinuity with shearing strength heterogencity estimates the representational occasion of structural fece sample when carrying out the direct shear test interpretation of result.

(2) background technology

Before the present invention makes, still there is not direct shear test structural plane typical sample evaluation method at present.Rock mass structural plane shearing strength has the heterogencity feature, choose structural fece sample arbitrarily and carry out the shearing strength value that shearing strength value that direct shear test obtains can not be represented the original position rock mass discontinuity objectively, owing to do not have the representative evaluation method of structural fece sample, can't estimate the structural fece sample representativeness of direct shear test.

Studies show that, roughness coefficient is the deciding factor (Fig. 1) that influences structural face shear strength, and roughness coefficient increases rule decay and increases the good consistance of rule tool that decays with shearing strength with sampling size with sampling size, so can estimate typical sample by the relation of the roughness coefficient orientation statistical value of the roughness coefficient orientation statistical value of joint straight shear test sample and original position rock mass discontinuity.

(3) summary of the invention

The objective of the invention is to solve owing to there is not direct shear test structural plane typical sample evaluation method, and can't determine the shortcoming that concerns between direct shear test shearing strength value and the original position rock mass structural plane shearing strength value, provide a kind of principle simple, easy to operate, with low cost, result of use is good, is convenient to estimate the method for the joint straight shear test typical sample with shearing strength heterogencity.

For this reason, the present invention is by the following technical solutions:

A kind of representative evaluation method of rock mass discontinuity sample comprises following sequential steps:

(1) on selected rock mass discontinuity sample and original position rock mass discontinuity, distinguishes the rating test direction respectively, the roughness coefficient direction of measurement of rock mass discontinuity sample and original position rock mass discontinuity is consistent;

(2) according to the direction of demarcating, the rock mass discontinuity sample is carried out the directed statistical measurement of roughness coefficient, try to achieve the roughness coefficient eigenwert JRC of rock mass discontinuity sample ₀

(3) in position on the rock mass discontinuity, along the direction of demarcating, arrange the measurement line segment that is no less than 30 equably according to the length of rock mass discontinuity sample, carry out the directed statistical measurement of roughness coefficient, try to achieve the original position rock structural plane roughness coefficient eigenwert JRC of specimen size ₀ ^*

(4) by $K=\frac{|\mathrm{JR}{C}_0-\mathrm{JR}{C_0}^{*}|}{\mathrm{JR}{C_0}^{*}}$ The representativeness of evaluation structure interview sample.K=0～0.15, the structural fece sample representativeness is fine; K=0.15～0.4, structural fece sample is better representative; K=0.4～0.7, the structural fece sample representativeness is medium; K=0.7～1, the structural fece sample representativeness is relatively poor; K 〉=1, the structural fece sample representativeness is very poor.

Employing the present invention have the following advantages: the present invention compared with prior art, direct shear test structural plane typical sample evaluation method principle is simple, easy to operate, with low cost, result of use is good, be convenient to estimate the typical sample of direct shear test structural plane, have bigger implementary value and economic results in society with shearing strength heterogencity.

(4) description of drawings

Fig. 1 is the graph of relation of roughness coefficient, shearing strength and sampling size.

(5) embodiment

(day waste level ground hydroenergy storage station grouan NEE group joint 20cm * 20cm) go up rating test direction respectively with original position rock mass discontinuity (open-air grouan NEE joint) is consistent the roughness coefficient direction of measurement of rock mass discontinuity sample and original position rock mass discontinuity at selected rock mass discontinuity sample; According to the direction of demarcating, (16 contour curves of the upper and lower dish of test direction of day waste level ground hydroenergy storage station grouan NEE group joint 20cm * 20cm) carry out the directed statistical measurement of roughness coefficient, try to achieve the roughness coefficient eigenwert JRC of rock mass discontinuity sample to the rock mass discontinuity sample ₀=6.97; In position on the rock mass discontinuity (open-air grouan NEE joint), along the direction of demarcating, arrange the measurement line segment that 80 sample lengths are 20cm equably according to the length of rock mass discontinuity sample, carry out the directed statistical measurement of roughness coefficient, try to achieve the original position rock structural plane roughness coefficient eigenwert JRC of specimen size ₀ ^*=8.02; It waste level ground hydroenergy storage station grouan NEE group joint 20cm * 20cm direct shear test sample JRC ₀=6.97, $K=\frac{|{\mathrm{JRC}}_0-{{\mathrm{JRC}}_0}^{*}|}{{{\mathrm{JRC}}_0}^{*}}=0.13,$ Be that NEE joint samples representativeness is fine.

Claims (1)

1, a kind of representative evaluation method of rock mass discontinuity sample is characterized in that comprising following sequential steps:

(1) on selected rock mass discontinuity sample and original position rock mass discontinuity, distinguishes the rating test direction respectively, the roughness coefficient direction of measurement of rock mass discontinuity sample and original position rock mass discontinuity is consistent;

(2) according to the direction of demarcating, the rock mass discontinuity sample is carried out the directed statistical measurement of roughness coefficient, try to achieve the roughness coefficient eigenwert JRC of rock mass discontinuity sample ₀

(3) in position on the rock mass discontinuity, along the direction of demarcating, arrange the measurement line segment that is no less than 30 equably according to the length of rock mass discontinuity sample, carry out the directed statistical measurement of roughness coefficient, try to achieve the original position rock structural plane roughness coefficient eigenwert JRC of specimen size ₀ ^*

(4) by $K=\frac{|\mathrm{JR}{C}_0-{{\mathrm{JRC}}_0}^{*}|}{{{\mathrm{JRC}}_0}^{*}}$ The representativeness of evaluation structure interview sample.K=0～0.15, the structural fece sample representativeness is fine; K=0.15～0.4, structural fece sample is better representative; K=0.4～0.7, the structural fece sample representativeness is medium; K=0.7～1, the structural fece sample representativeness is relatively poor; K 〉=1, the structural fece sample representativeness is very poor.

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