CN109060537A - The equivalent area test method of irregular soft rockmass point load strength - Google Patents
The equivalent area test method of irregular soft rockmass point load strength Download PDFInfo
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- CN109060537A CN109060537A CN201811029634.4A CN201811029634A CN109060537A CN 109060537 A CN109060537 A CN 109060537A CN 201811029634 A CN201811029634 A CN 201811029634A CN 109060537 A CN109060537 A CN 109060537A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B21/00—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
- G01B21/28—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring areas
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
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Abstract
A kind of equivalent area test method of irregular soft rockmass point load strength.Its practice is mainly: A, sample prepares: the upper and lower two o'clock for immediate vicinity of materialsing measures and records the mean breadth and load(ing) point spacing of sample smallest cross-sectional as load(ing) point, and the ratio between load(ing) point spacing and mean breadth are 0.3-1.0；B, Point Loading Strength Test: breaking section is efficiency test through entire sample and by two load(ing) points after test；C, A-B operation is repeated, until efficiency test number is more than or equal to 10；D, the point load strength I of the sample of n-th efficiency test the calculating of sample point load strength: is obtained by following formulas n, Is n=Pn/(1.43WnDn)；E, the calculating of soft rockmass point load strength: by each point load strength Is nIn maximum value, secondary maximum value, minimum value, secondary minimum value remove, then find out remaining point load strength Is nAverage value to get.The point load strength value that the method is measured is more reliable, more acurrate.
Description
Technical field
The present invention relates to the equivalent area test methods of irregular soft rockmass point load strength.
Background technique
Uniaxial compressive strength is that rock strength classification, Weathering Zones of Igneous Rock divide the important indicator of band, it is necessary to by laboratory into
Row uniaxial compressive strength test obtains.And the sample of uniaxial compressive strength usually requires core-drilling at the scene, then is transported to reality
Room cutting polishing is tested, preparation process is difficult complicated.For the rock of weak, serious weathering, joints development, due to cannot normally take
It complete core or cannot be processed standard sample out, be difficult to adopt the rock test method measurement intensity of standard.
Face this problem, the method that International Society of Rock Mechanics (ISRM) has formulated Point Loading Strength Test, by sample
It is placed between two load cones of Point Loading Strength Test instrument, applies and point loading is concentrated to destroy sample, find out the point loading of rock
Then intensity is scaled uniaxial compressive strength.Since required failing load is smaller, Point Loading Strength Test instrument is small in size, quality
Gently, easy to carry, outer indoors or scene can be tested.The requirement tested to sample is relatively low, is omited with iron hammer to sillar
Add finishing, greatly reduces the cost of manufacture of sample, improve test efficiency.The rock that can not be carried out to code test is strong
Degree measurement is provided convenience, and is widely applied.
The principle of Point Loading Strength Test method are as follows: compression is only distributed near sample load(ing) point and one depthkeeping of surface
Degree, interior on a large scale is uniform tensile stress, finally in drawing crack destruction.The mechanics of point load strength is substantially sample in two load cones
Between breaking unit area on the maximum tension stress that can bear.Packet sample regular for homogeneous, when sample thickness D and
When mean breadth W is located at specification restriction range, it should be destroyed along the smallest cross-sectional for crossing two load(ing) points under point loading effect, it is real at this time
The area that tensile stress is born on border is equal to the thickness D (the distance between two load cones, load(ing) point spacing) and the smallest cross-sectional of sample
The product of mean breadth W (top width of smallest cross-sectional and the average value of bottom width), thus the calculating formula of point load strength
For Is=P/ (WD)；Wherein IsFor point load strength, P is failing load (when sample destroys, the pressure applied is bored in load).
Packet regular for homogeneous, the stress collection middle section of test was the smallest cross-sectional of two load(ing) points, so that in fact
Border breaking section can be overlapped with smallest cross-sectional；The point load strength that Point Loading Strength Test obtains is accurate and reliable.But it is right
In irregular soft rockmass, practical breaking section can be overlapped with the fragile section crossed near two load(ing) points, and fragile section is often
It is not overlapped with smallest cross-sectional, namely practical breaking section will be generally offset from smallest cross-sectional, its practical breaking section product is caused to be greater than
Minimum sectional area, point load strength IsCalculated value it is bigger than normal, the point load strength I measuredsAs rock strength classification, rock mass wind
Change divide band according to unreliable, inaccurate.
Summary of the invention
The object of the present invention is to provide the equivalent area test method of irregular soft rockmass point load strength, this method is measured
Point load strength value and soft rockmass practical point load strength it is closer, test value is more reliable, accurate, can be rock strength point
Class, Weathering Zones of Igneous Rock a point band provide more reliable, more accurate test basis.
The technical scheme adopted by the invention for realizing the object of the invention is, a kind of irregular soft rockmass point load strength etc.
Imitate area test method, comprising the following steps:
A, sample prepares:
Choose strip thickness direction perpendicular to stratification irregular soft rock mass as sample, center of materialsing is attached
Close upper and lower two o'clock measures and records mean breadth and load(ing) point that sample crosses the smallest cross-sectional of two load(ing) points as load(ing) point
Spacing measures accurately to 0.1mm；And load(ing) point spacing is less than or equal to 15mm, is more than or equal to 100mm, load(ing) point spacing and is averaged
The ratio between width is 0.3-1.0；
B, Point Loading Strength Test:
The sample of A step is subjected to Point Loading Strength Test, records failing load；Breaking section runs through entire sample after test
And passing through two load(ing) points is efficiency test；
C, the operation of A step, B step is repeated, until efficiency test number N is more than or equal to 10；
D, the calculating of sample point load strength:
The point load strength I of the sample of n-th efficiency test is obtained by following formulas n,
Is n=Pn/(1.43WnDn)
In formula, subscript n indicates the serial number of efficiency test, n=1,2,3 ..., N；PnFor the destruction lotus of n-th efficiency test
It carries, WnFor n-th efficiency test sample cross two load(ing) points smallest cross-sectional mean breadth, DnFor the examination of n-th efficiency test
The load(ing) point spacing of sample；
E, the calculating of soft rockmass point load strength:
By the point load strength I of the sample of each secondary efficiency tests nIn maximum value, secondary maximum value, minimum value, secondary minimum value
Remove, then finds out the point load strength I of the sample of remaining efficiency tests nAverage value, the point lotus of as irregular soft rockmass
Carry intensity Is。
Compared with prior art, the beneficial effects of the present invention are:
Applicants have found that for irregular soft rockmass, when Point Loading Strength Test, practical breaking section will not be with
Smallest cross-sectional is overlapped；Practical breaking section product is greater than minimum sectional area, practical breaking section product and the ratio of minimum sectional area
Desired value is 1.43；The equivalent area coefficient 1.43 of irregular soft rockmass Point Loading Strength Test in other words.And then it will be irregular
The expression formula of the point load strength of soft rockmass Point Loading Strength Test is by Is=P/ (WD) is modified to Is=P/ (1.43WD).Amendment
The reference area 1.43WD in expression formula is closer to practical breaking section product afterwards, the point load strength I measuredsBe worth it is more acurrate,
Band can be divided to provide more reliable, more accurate test basis for rock strength classification, Weathering Zones of Igneous Rock.
The invention will be further described With reference to embodiment.
Specific embodiment
Embodiment
A kind of specific embodiment of the invention is a kind of equivalent area test side of irregular soft rockmass point load strength
Method, comprising the following steps:
A, sample prepares:
Choose strip thickness direction perpendicular to stratification irregular soft rock mass as sample, center of materialsing is attached
Close upper and lower two o'clock measures and records mean breadth and load(ing) point that sample crosses the smallest cross-sectional of two load(ing) points as load(ing) point
Spacing measures accurately to 0.1mm；And load(ing) point spacing is less than or equal to 15mm, is more than or equal to 100mm, load(ing) point spacing and is averaged
The ratio between width is 0.3-1.0；
B, Point Loading Strength Test:
The sample of A step is subjected to Point Loading Strength Test, records failing load；Breaking section runs through entire sample after test
And passing through two load(ing) points is efficiency test；
C, the operation of A step, B step is repeated, until efficiency test number N is more than or equal to 10；
D, the calculating of sample point load strength:
The point load strength I of the sample of n-th efficiency test is obtained by following formulas n,
Is n=Pn/(1.43WnDn)
In formula, subscript n indicates the serial number of efficiency test, n=1,2,3 ..., N；PnFor the destruction lotus of n-th efficiency test
It carries, WnFor n-th efficiency test sample cross two load(ing) points smallest cross-sectional mean breadth, DnFor the examination of n-th efficiency test
The load(ing) point spacing of sample；
E, the calculating of soft rockmass point load strength:
By the point load strength I of the sample of each secondary efficiency tests nIn maximum value, secondary maximum value, minimum value, secondary minimum value
Remove, then finds out the point load strength I of the sample of remaining efficiency tests nAverage value, the point lotus of as irregular soft rockmass
Carry intensity Is。
Verification experimental verification
Using with batch of irregular soft phyllite sample, its lotus is measured by existing Point Loading Strength Test method
Load intensity is 2.00MPa, is 0.76MPa by the point load strength that the method for the present invention measures；Meanwhile to the reality of the sample after test
Breaking section product in border carries out precise measurement, its practical breaking section product value is calculated obtains in fact as load receiving area
The point load strength on border is 0.69MPa.Compared with actual point load strength, the error of the method for the present invention be (0.76-0.69)/
0.69=10.1%, and existing Point Loading Strength Test method error is (2.00-0.69)/0.69=189.9%, the present invention
The error of method is far below existing Point Loading Strength Test method.
Claims (1)
1. a kind of equivalent area test method of irregular soft rockmass point load strength, comprising the following steps:
A, sample prepares:
Choose strip thickness direction perpendicular to stratification irregular soft rock mass as sample, immediate vicinity of materialsing
Upper and lower two o'clock measures and records mean breadth and load(ing) point spacing that sample crosses the smallest cross-sectional of two load(ing) points as load(ing) point,
Measurement is accurately to 0.1mm；And load(ing) point spacing be less than or equal to 15mm, be more than or equal to 100mm, load(ing) point spacing and mean breadth it
Than for 0.3-1.0；
B, Point Loading Strength Test:
The sample of A step is subjected to Point Loading Strength Test, records failing load；Breaking section through entire sample and leads to after test
Crossing two load(ing) points is efficiency test；
C, the operation of A step, B step is repeated, until efficiency test number N is more than or equal to 10；
D, the calculating of sample point load strength:
The point load strength I of the sample of n-th efficiency test is obtained by following formulas n,
Is n=Pn/(1.43WnDn)
In formula, subscript n indicates the serial number of efficiency test, n=1,2,3 ..., N；PnFailing load, W for n-th efficiency testn
For n-th efficiency test sample cross two load(ing) points smallest cross-sectional mean breadth, DnFor the sample of n-th efficiency test
Load(ing) point spacing；
E, the calculating of soft rockmass point load strength:
By the point load strength I of the sample of each secondary efficiency tests nIn maximum value, secondary maximum value, minimum value, secondary minimum value go
Fall, then finds out the point load strength I of the sample of remaining efficiency tests nAverage value, the point loading of as irregular soft rockmass
Intensity Is。
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| CN201811029634.4A CN109060537B (en) | 2018-09-05 | 2018-09-05 | Equivalent area test method for load strength of irregular soft rock point |
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| CN201811029634.4A CN109060537B (en) | 2018-09-05 | 2018-09-05 | Equivalent area test method for load strength of irregular soft rock point |
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| CN109060537B CN109060537B (en) | 2020-08-28 |
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Citations (6)
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| KR100825272B1 (en) * | 2007-01-19 | 2008-04-25 | 울산과학대학 산학협력단 | Point loading strength tester |
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| CN203117044U (en) * | 2013-02-27 | 2013-08-07 | 浙江土工仪器制造有限公司 | Mortar masonry point load tester |
| US9432901B1 (en) * | 2015-07-24 | 2016-08-30 | Cisco Technology, Inc. | System and method to facilitate radio access point load prediction in a network environment |
| CN108398331A (en) * | 2018-02-23 | 2018-08-14 | 山东大学 | A kind of rock multiple information acquisition system and test method |
| CN108444825A (en) * | 2018-03-07 | 2018-08-24 | 华北水利水电大学 | Utilize the method for point load strength quantitative identification granite alteration extent |
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2018
- 2018-09-05 CN CN201811029634.4A patent/CN109060537B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100825272B1 (en) * | 2007-01-19 | 2008-04-25 | 울산과학대학 산학협력단 | Point loading strength tester |
| CN102721396A (en) * | 2012-06-28 | 2012-10-10 | 中钢集团马鞍山矿山研究院有限公司 | Novel method for measuring area of rock point load test fracture surface |
| CN203117044U (en) * | 2013-02-27 | 2013-08-07 | 浙江土工仪器制造有限公司 | Mortar masonry point load tester |
| US9432901B1 (en) * | 2015-07-24 | 2016-08-30 | Cisco Technology, Inc. | System and method to facilitate radio access point load prediction in a network environment |
| CN108398331A (en) * | 2018-02-23 | 2018-08-14 | 山东大学 | A kind of rock multiple information acquisition system and test method |
| CN108444825A (en) * | 2018-03-07 | 2018-08-24 | 华北水利水电大学 | Utilize the method for point load strength quantitative identification granite alteration extent |
Non-Patent Citations (3)
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| M. KOHNO ET.AL: "Short communicationFull text access", 《INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES》 * |
| 向桂馥等: "岩石点荷载试验资料的统计分析及强度计算公式的探讨", 《岩土力学与工程学报》 * |
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