CN105241510B - The assay method of tunnel surrounding prestressed reinforcement rock-bolt length and radial direction prestress value - Google Patents

The assay method of tunnel surrounding prestressed reinforcement rock-bolt length and radial direction prestress value Download PDF

Info

Publication number
CN105241510B
CN105241510B CN201510767522.9A CN201510767522A CN105241510B CN 105241510 B CN105241510 B CN 105241510B CN 201510767522 A CN201510767522 A CN 201510767522A CN 105241510 B CN105241510 B CN 105241510B
Authority
CN
China
Prior art keywords
msub
mrow
rock
tunnel
mfrac
Prior art date
Application number
CN201510767522.9A
Other languages
Chinese (zh)
Other versions
CN105241510A (en
Inventor
贺可强
潘信梅
张娟
Original Assignee
青岛理工大学
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 青岛理工大学 filed Critical 青岛理工大学
Priority to CN201510767522.9A priority Critical patent/CN105241510B/en
Publication of CN105241510A publication Critical patent/CN105241510A/en
Application granted granted Critical
Publication of CN105241510B publication Critical patent/CN105241510B/en

Links

Abstract

The invention discloses tunnel surrounding prestressed reinforcement rock-bolt length and the assay method of radial direction prestress value, according to country rock elastic plastic theory and Plastic Zone Distribution rule, on the basis of comprehensive determination tunnel plastic circle radius R and pressure from surrounding rock, determine that tunnel surrounding reinforces anchor pole minimum length and radially minimum prestress value.The beneficial effects of the invention are as follows:According to country rock elastic plastic theory and Plastic Zone Distribution rule, on the basis of comprehensive determination tunnel plastic circle radius R and pressure from surrounding rock, determine that tunnel surrounding reinforces anchor pole minimum length and radially minimum prestress value, calculating process definitely, it is terse, the result accuracy surveyed is higher, it is more accurate, it is smaller with actual error, can preferably Guiding Practice.

Description

The assay method of tunnel surrounding prestressed reinforcement rock-bolt length and radial direction prestress value
Technical field
The present invention relates to tunnel surrounding stress determination and Analyses of Tunnel Wall Rock Stability is evaluated and liner support reinforcement design side Method field, and in particular to the assay method of tunnel surrounding prestressed reinforcement rock-bolt length and radial direction prestress value.
Background technology
In recent years, with increasing Tunnel Engineering construction, China is in infrastructure such as traffic, water conservancy and hydropower, municipal administrations Field achieves the achievement to attract people's attention, particularly nearly ten years, more achieves the development advanced by leaps and bounds, while in underground engineering Design and construction technique level there has also been large increase.
Currently in order to keeping the use headroom of tunnel cave section, the various loads being likely to occur are born, ensure tunnel cave country rock Stable and security, usually need to set supporting construction during tunnel excavation.Support structure design for a long time often uses steel Yoke and concrete lining, although with sufficiently large rigidity and cross dimensions, the intensity of itself is completely dependent on, passive The powerful broken-rock pressure of country rock is born to maintain the stabilization of chamber so that using these traditional supportings although spending substantial amounts of work Journey expense, preferable Expected Results is but extremely difficult to, simultaneously because its slow, structure of construction and country rock phase separation etc. are intrinsic weak Point, the destruction of supporting construction and the slump of country rock are often what is be difficult to avoid that.With the popularization of New Austrian Tunneling Method, we, which can be found that, encloses The appropriateness deformation of rock has certain benefit for the resistance to overturning of tunnel structure, so in the construction of modern tunnel, shotcrete Supporting can carry out supporting in time as one kind, limit country rock excessive deformation and loosen, and it is certain that and can allows country rock to occur Deformation, the new support pattern for the features such as making full use of surrouding rock deformation and increasing the stability in tunnel, have started to extensive It is applied to modern tunnel support conceptual design.The support pattern for the main use that bolt-spary supports is constructed as New Austrian Tunneling Method, its Function is the important component for promoting country rock to be changed into supporting construction from load thing, plays making certainly for country rock to greatest extent With safeguarding the stabilization of chamber with less supporting drag.
The general design method of bolt-spary supports includes following several method at present:(1) engineering analog method.This method is mainly It is directly true with reference to the experience of built engineering according to country rock grade and tunnel specification on the basis of classifying to country rock Determine shotcrete parameter and construction method;(2) information design method.This design method be using live measured information as design considerations, its The characteristics of maximum is while the result of measurement is fed back in design and construction, to make plan while carry out various measurements in construction When design, construction become to more conform to live actual, finally determine supporting parameter;(3) theoretical calculation.This method is to survey On the premise of obtaining rock mass and supporting mechanics parameter, according to coffer mechanics feature founding mathematical models, pass through and calculate determination supporting ginseng Several methods.This method is the development based on rock mass mechanics, considers country rock and supporting collective effect and gradually forms and develop Get up.Its specific mechanical model and computational methods currently have approximate mainly depending on rock mass attribute and structure type Analytical algorithm and by means of numerical solutions such as the finite element of computer, boundary elements.Though above-mentioned Forecasting Methodology is general in bolt-spary supports Design in played important function, but process is established by analyze above-mentioned design method, it can be found that the above method is present The deficiency of following several respects:Engineering analog method is with the data that information design method mainly measures using practical experience or actually as design Foundation, but often influenceed by objective practice condition, measurement accuracy, measuring method and survey tool, and cause it in reality Border use on larger error be present, while lack theoretical calculation according to and so that the above method really can not be effectively used in In engineering construction;Although theoretical calculation development is ripe, what is used is this computational methods and few, this be mainly because Changeable for wall rock geology complex, its mechanical model and Mechanics Parameters of Rock Mass are not easy accurate test and determined, so typically only As a calculation means in design, mutually checked with other design methods.
Being analyzed more than to obtain, and the design both at home and abroad for underground chamber bolt-spary supports form at present does not have complete set Theoretical calculation system, existing theoretical calculation method and be difficult effectively accurately be applied to support structure design, therefore, The present invention determines tunnel plastic circle radius R and pressure from surrounding rock according to country rock elastic plastic theory and Plastic Zone Distribution rule comprehensive On the basis of, determine that tunnel surrounding reinforces anchor pole minimum length and radially minimum prestress value.
The content of the invention
The shortcomings that in above-mentioned traditional underground chamber liner Design Method of Reinforcing and deficiency, according to country rock elastic plastic theory And Plastic Zone Distribution rule, circular tunnel pressure from surrounding rock and plastic circle radius are studied and determine, and it is basic according to above-mentioned two Anchor pole minimum length and radially minimum reinforcing prestress value are reinforced in parametric synthesis determination, are ensureing circular tunnel stabilization to reach Under the premise of more save engineering cost with shortening the purpose of construction period, there is good practical valency in subterranean tunnel reinforcing engineering Value.
In order to reach above-mentioned purpose, the present invention adopts the following technical scheme that:
The assay method of tunnel surrounding prestressed reinforcement rock-bolt length and radial direction prestress value, including:
The first step:Determine the natural stress of Rock Mass;
Second step:Determine the physical and mechanical parameter of Rock Mass;
3rd step:Tunnel surrounding section plastic circle radius is determined according to the natural stress and physical and mechanical parameter of rock mass;
4th step:According to the natural stress of rock mass, physical and mechanical parameter, tunnel excavation radius of circle and tunnel plastic circle radius Determine Tunnel Surrounding Rock Pressure;
5th step:The horizontal spacing and longitudinal pitch of Tunnel Surrounding Rock Pressure, adjacent anchor pole in the 4th step determine tunnel Road reinforces anchor pole radial direction prestress value;
6th step:The optimal design length of tunnel reinforcement anchor pole is determined according to anchor rod anchored section of optimization length.
Further, the natural stress σ of Rock Mass is determined in the first step using drilling set core stress contact methodZ, Comprise the following steps that:
1) at tunnel surrounding reconnaissance, drill and beat measured hole in bottom hole;
2) strain gauge is loaded in measured hole, strain gauge is connected with deformeter;
3) deformeter record initial reading, contact stress is bored by covering, record strain-ga(u)ge reading Ua、Ub、UcUntil stress is complete Complete solution removes;
4) fracture core, is tried to achieve according to formula (1)
In formula:σ1Maximum principal stress in-cell cube, σ3Minimum principal stress in-cell cube, the compression strength of E-rock; R*The radius of-measured hole;Ua、Ub、UcShift value measured by-deformeter a, b, c;2 θ-determined according to tan2 θ calculated values;
5) the natural stress σ of rock mass is tried to achieve according to formula (6)Z
Further, the physical and mechanical parameter of country rock includes country rock internal friction angle parameter in the second stepInterior friction Angular dimensions is equal to the reduction coefficient that sillar internal friction angle standard value is multiplied by setting, and reduction coefficient determines according to cranny development degree, (crack agensis, crack are relatively developed, cranny development, and reduction coefficient corresponding to cataclastic texture is 0.90~0.95,0.85 respectively~ 0.90,0.80~0.85,0.75~0.80).
Further, the physical and mechanical parameter of country rock includes country rock internal cohesion parameter c, internal cohesion in the second step Parameter is multiplied by the reduction coefficient of setting by country rock internal cohesion standard value, and reduction coefficient is 0.2~0.3.
Further, tunnel surrounding section plastic circle radius R obtains according to formula (3) in the 3rd step:
In formula:R-tunnel plastic circle radius;Ro- relaxation zone radius (takes Ro=r).
Further, Tunnel Surrounding Rock Pressure σ is tried to achieve according to formula (4) in the 4th stepw
In formula:R-tunnel excavation radius of circle.
Further, in the 5th step, according to ground anchorage and concrete spraying support engineering legislation, between anchor pole Away from not be preferably greater than rock-bolt length 1/2, when wall rock condition is poor, crustal stress is higher or adit digging size is larger, anchor pole cloth Putting spacing should suitably encrypt.For the suitable 0.50m~1.00m of anchor pole spacing in IV, V grade of country rock, and it is true to cannot be greater than 1.25m The horizontal spacing of fixed adjacent two anchor poleAnd longitudinal pitch Sb
Further, in the 5th step, tried to achieve according to formula (5) and reinforce anchor pole radial direction prestress value fy
Further, according to ground anchorage and concrete spraying support engineering legislation, anchor pole is calculated by formula (6) The optimization length Δ l of anchoring section:
In formula:D-anchorage body diameter;fmsUltimate bond stress between-anchoring body surface and surrounding Rock And Soil; η-anchoring body bonds safety coefficient;The radical of n-reinforcing bar or steel strand wires;The adhesion strength at ξ-interface reduces coefficient, takes 0.7- 0.85;Influence coefficient of the ψ-anchoring strength to adhesion strength.
Further, in the 6th step, tunnel reinforcement anchor pole optimal design length L calculates according to formula (7):
L=R-r+ Δs l (7).
In above formula (7), R-r is exactly the length of free section.
The present invention operation principle be:
Circular tunnel plastic circle radius refers to that country rock is plastically deformed and the boundary point of elastic deformation to the circular tunnel center of circle Distance.The determination of plastically deforming area and elastic deformation area's boundary point is related to the determination of suspension roof support anchoring section initial point position, So the determination of plastic circle radius is related to the determination of whole combined bolting and shotcrete design parameter.And the sarifying section of surrounding rock is top layer after excavating Country rock gradually extends with the generation of displacement with development, destruction to depths, the part rock for being destroyed its continuity and integrality Stone region, because sarifying section of surrounding rock radius is directly connected to the safety of Tunnel Engineering, so strictly to control country rock not produce pine Dynamic area, i.e. Ro=r.
1. use elastic and plastic properties theoretical calculation pressure from surrounding rock, it is assumed that a horizontal circle is excavated in natural stress field rock mass Tunnel cave, caused surrouding rock stress τ=0, then σb、σθIt is principal stress.According to mole-coulomb strength condition as country rock The condition of palsticity, then when country rock produces plastic zone, there is the redistribution figure (such as Fig. 5) of stress behind plastic zone, in its plastic zone Stress σbAnd σθFollowing formula will be met:
I.e. all regions for meeting above formula will all produce plastic deformation, plastic circle occurs.If geologic feature is neglected to enclosing The influence of rock stress distribution, because surrouding rock stress distribution is axisymmetric, therefore plastic circle is also axisymmetric.The rock in plastic circle The cohesive force c of stone, internal friction angleIt will be reduced with elastic modulus E.The ungratified region of stress, it is still elasticity in country rock Deformed area.Its stress-strain relation still obeys Hooke's law.In plastic zone, the equilibrium condition that every bit stress must meet is i.e.:
The stress of plastic zone can be tried to achieve by above-mentioned formula (9):
From above formula, the stress σ of plastic zoneb、σθOnly it is radius vector b function, it changes with b change.In plastic zone Tangential stress σθReduce a lot, the degree of reduction is relevant with the size being plastically deformed, and plastic deformation is maximum on cave wall, therefore σθDrop Low is most, but and is not zero.Because rock also has certain bearing capacity after generating plastic deformation.In answering for elastic region Power but slightly raises, and this is due to a part of stress release in plastic zone, and a part of stress then imputes to the knot of elastic region Fruit.
The stress of elastic region is calculated as follows:
In formula:
The radius vector of b-calculating point;
σRThe borderline radial stress in-elastic and plastic properties area (can be regarded as active force of the plastic circle to elastic ring);
The radius of R-plastic circle;
σbThe radial stress of-rock mass
σθThe tangential stress of-rock mass.
For bullet, the modeling borderline any unit in area, it had both belonged to elastic region unit, belonged to plastic zone unit again, thus The unit should meet the condition that above-mentioned plastic zone and elastic region unit should meet simultaneously.(the r=i.e. on elastic and plastic properties area border R formula (14)) below is set up:
bθ)Bullet=(σbθ)Modeling (14)
The plastic zone radius R under the conditions of non-support is can obtain by above formula (14):
The radius of plastic zone is maximum in this case.
If wanting to make plastic region not formed, be i.e. during R=r, obtained by pressure from surrounding rock formula (see principle 2) and do not form plastic zone Required Support Resistance:
The maximum Support Resistance needed for elastic stress field is in here it is tunnel is maintained.Its size only with primary stress field And lithological indicators are relevant, and it is unrelated with tunnel size.Above formula σwIt is actually consistent with the stress expression formula on Elastic-Plastic Boundary, say Bright Support Resistance can change the stress in the size and plastic zone of plastic zone, and can not change the stress of Elastic-Plastic Boundary.It is actual Upper supporting is built after tunnel excavation in certain time, plastic region and its deformation occurrence and development.Needed for therefore The numerical value that Support Resistance will be determined less than above formula.
According to our definition to relaxation zone, i.e. the borderline tangential stress of relaxation zone is primary stress, i.e. στz, can :
Relaxation zone radius can be obtained:
It can be seen that there is certain relation in relaxation zone radius and plastic zone radius.
2. pressure from surrounding rock refers to cause underground excavation spatial peripheral rock mass and Support Deformation or the active force of destruction.With new The flexible support forms such as extensive use of the method difficult to understand in constructing tunnel, bolt-spary supports use it is also more and more, pressure from surrounding rock Result of calculation necessarily determines that the formal character of supporting construction, parameter are chosen.The present invention is carried out using following pressure from surrounding rock principle Pressure from surrounding rock calculates:
As R=b, σbR, obtained by calculus principle solving plastic zone mechanical equilibrium condition formula:
By:
Then:
The borderline radial stress σ in elastic and plastic properties area can be tried to achieveRFor:
In derivation, consider the influence of cohesive force c on Elastic-Plastic Boundary, can obtain:
When making r=b, σrw, then above formula be changed into:
Above formula is pressure from surrounding rock solution formula.σ in formulawTo act on the interior pressure on cave wall, can be regarded as here Supporting construction is to the active force of country rock, and its numerical value is equal to shoulder bed effects in the power in supporting construction, therefore σwFor required country rock pressure Power.The size of its pressure from surrounding rock is except the natural stress σ with rock massz, country rock intensive parameter c,And the size of tunnel cave is relevant Outside, also controlled by the size of plastic zone, its change into opposite with the size of plastic zone radius.When R is maximum, country rock Pressure σwFor minimum.When not allowing plastic zone occur.Even during R=r, pressure from surrounding rock σwFor maximum, its value can substitute into R=r, Try to achieve:
The beneficial effects of the invention are as follows:
1) according to country rock elastic plastic theory and Plastic Zone Distribution rule, tunnel plastic circle radius R and country rock are determined comprehensive On pressure-based, determine that tunnel surrounding reinforces anchor pole minimum length and radially minimum prestress value, calculating process definitely, letter Practice, the result accuracy surveyed is more accurate, smaller with actual error.
2) according to knowable to calculating, rock-bolt length obtained by assay method of the invention has higher accuracy, for circle Tunnel Rock Bolt protection has preferable practical value.
Brief description of the drawings
Fig. 1 is flow chart of the present invention;
Fig. 2 is the horizontally disposed figure of measured hole deformeter;
Fig. 3 is anchor pole interplanar spacing schematic diagram;
Fig. 4 is anchor pole section layout drawing;
Fig. 5 is the redistribution figure for occurring stress behind plastic zone.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete Whole description.
The method that the present invention is now illustrated by taking certain circular tunnel engineering as an example is used as optimum embodiment.Utilize this method The design of bolt-spary supports structural anchor bar length optimization is carried out to the circular tunnel engineering.Specific implementation step is as follows:
Step 1:The natural stress σ of tunnel surroundingZDetermination
The natural stress σ of rock massZRefer to the stress being present in before Human dried bloodstains in rock mass, according to tunnel excavation section Radius r and edpth of tunnel and Rock Mass property, the natural stress σ of synthesis measuring tunnel surrounding rock massZWith physical and mechanical parameterThe circular tunnel depth is about 100m, excavates chamber radius r=3m, country rock severe γ=18kN/m3
(1) the natural stress σ of this circular tunnel engineering rock masszFor:
According to record strain-ga(u)ge reading Ua=14.8, Ub=13.0, Uc=8.5, and the E=of rock is asked for indoors 47.90, measurement pore radius R*=130.Under the conditions of strain gauge is using mutual placement at 45 °, then σ1、σ3It can be asked by formula once Solution:
The natural stress σ of rock mass that can then askZFor:
Step 2:Physical and mechanical parameterIt is determined that:
Rock mass physical physical and mechanical parameter can determine that according to experimental dataFor:Internal friction angleIt is interior viscous Poly- power c=0.2MPa
Step 3:The determination of tunnel surrounding section plastic circle radius
Circular tunnel plastic circle radius refers to that country rock is plastically deformed and the boundary point of elastic deformation to the circular tunnel center of circle Distance.Circular tunnel plastic circle radius R is calculated using (formula 3):
This circular tunnel engineering plasticity circle radius R is:
R=3.67m
Step 4:The determination of circular tunnel pressure from surrounding rock
Pressure from surrounding rock refers to cause underground excavation spatial peripheral rock mass and Support Deformation or the active force of destruction, the present invention to adopt Pressure from surrounding rock σ is determined with below equationWSize.
Step 5:Reinforce the determination of anchor pole radial direction prestress value
1) the transverse direction and longitudinal direction spacing of anchor poleSbIt must determine
By《Ground anchorage and concrete spraying support engineering legislation》In GB50086-2011 the 7.3.2.2 articles can Know, anchor pole spacing is not preferably greater than the 1/2 of rock-bolt length.When wall rock condition is poor, crustal stress is higher or adit digging size is larger When, anchor pole arrangement spacing should be encrypted suitably.For the suitable 0.50m~1.00m of anchor pole spacing in IV, V grade of country rock, and must not be big In 1.25m.The spacing of anchor pole is can determine that according to above-mentioned regulation and engineering experienceSb=0.8m.
2) determination of anchor pole radial direction prestress value is reinforced
The supporting reaction provided according to hypothesis suspension roof support structure tunnel cave wall is generally evenly distributed in the model of support action In enclosing, then the anchor rod prestress power to be balanced is pressure from surrounding rock sum in the sphere of action of this anchor pole.Can be in the hope of every The limit pre-stress design value f provided needed for root anchor poley
Step 6:The determination of rock-bolt length in combined bolting and shotcrete
1) determination of anchor rod anchored length
According to《Ground anchorage and concrete spraying support engineering legislation》The 4.6.11 articles of GB50086-2011 takes anchor It is 1.6 that solid, which bonds safety coefficient K, the ultimate bond stress f between anchoring body surface and surrounding soilms=1000KPa, ξ= 0.85, ψ=1.6, anchor rod body diameter is selectedReinforcing bar.Try to achieve Δ l:
2) in bolt-spary supports rock-bolt length determination
Anchor pole free end length:
Δ L=R-r=3.67m-3.0m=0.67m
Rock-bolt length in bolt-spary supports:
L=R-r+ Δs l=3.67m-3.0m+4.08m=4.75m
Described above is only the preferred embodiment of the present invention, it is noted that for the ordinary skill people of the art For member, under the premise without departing from the principles of the invention, some improvements and modifications can also be made, these improvements and modifications also should It is considered as protection scope of the present invention.

Claims (10)

1. the assay method of tunnel surrounding prestressed reinforcement rock-bolt length and radial direction prestress value, it is characterised in that including:
The first step:Determine the natural stress of Rock Mass;
Second step:Determine the physical and mechanical parameter of Rock Mass;
3rd step:Tunnel surrounding section plastic circle radius is determined according to the natural stress and physical and mechanical parameter of rock mass;
4th step:Determined according to the natural stress of rock mass, physical and mechanical parameter, tunnel excavation radius of circle and tunnel plastic circle radius Tunnel Surrounding Rock Pressure;
5th step:The horizontal spacing and longitudinal pitch of Tunnel Surrounding Rock Pressure, adjacent anchor pole in the 4th step determine that tunnel adds Gu anchor pole radial direction prestress value;
6th step:The optimal design length of tunnel reinforcement anchor pole is determined according to anchor rod anchored section of optimization length.
2. assay method as claimed in claim 1, it is characterised in that using drilling set core stress contact method in the first step Determine the natural stress σ of Rock MassZ, comprise the following steps that:
1) at tunnel surrounding reconnaissance, drill and beat measured hole in bottom hole;
2) strain gauge is loaded in measured hole, strain gauge is connected with deformeter;
3) deformeter record initial reading, contact stress is bored by covering, record strain-ga(u)ge reading Ua、Ub、UcUntil stress solves completely Remove;
4) fracture core, is tried to achieve according to formula (1)
<mrow> <mfenced open = "{" close = ""> <mtable> <mtr> <mtd> <mrow> <msub> <mi>&amp;sigma;</mi> <mn>1</mn> </msub> <mo>=</mo> <mfrac> <mi>E</mi> <mrow> <mn>4</mn> <msup> <mi>R</mi> <mo>*</mo> </msup> </mrow> </mfrac> <mo>&amp;lsqb;</mo> <msub> <mi>U</mi> <mi>a</mi> </msub> <mo>+</mo> <msub> <mi>U</mi> <mi>c</mi> </msub> <mo>+</mo> <mfrac> <mn>1</mn> <msqrt> <mn>2</mn> </msqrt> </mfrac> <msqrt> <mrow> <msup> <mrow> <mo>(</mo> <msub> <mi>U</mi> <mi>a</mi> </msub> <mo>-</mo> <msub> <mi>U</mi> <mi>b</mi> </msub> <mo>)</mo> </mrow> <mn>2</mn> </msup> <mo>+</mo> <msup> <mrow> <mo>(</mo> <msub> <mi>U</mi> <mi>b</mi> </msub> <mo>-</mo> <msub> <mi>U</mi> <mi>c</mi> </msub> <mo>)</mo> </mrow> <mn>2</mn> </msup> </mrow> </msqrt> <mo>&amp;rsqb;</mo> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <msub> <mi>&amp;sigma;</mi> <mn>3</mn> </msub> <mo>=</mo> <mfrac> <mi>E</mi> <mrow> <mn>4</mn> <msup> <mi>R</mi> <mo>*</mo> </msup> </mrow> </mfrac> <mo>&amp;lsqb;</mo> <msub> <mi>U</mi> <mi>a</mi> </msub> <mo>+</mo> <msub> <mi>U</mi> <mi>c</mi> </msub> <mo>-</mo> <mfrac> <mn>1</mn> <msqrt> <mn>2</mn> </msqrt> </mfrac> <msqrt> <mrow> <msup> <mrow> <mo>(</mo> <msub> <mi>U</mi> <mi>a</mi> </msub> <mo>-</mo> <msub> <mi>U</mi> <mi>b</mi> </msub> <mo>)</mo> </mrow> <mn>2</mn> </msup> <mo>+</mo> <msup> <mrow> <mo>(</mo> <msub> <mi>U</mi> <mi>b</mi> </msub> <mo>-</mo> <msub> <mi>U</mi> <mi>c</mi> </msub> <mo>)</mo> </mrow> <mn>2</mn> </msup> </mrow> </msqrt> <mo>&amp;rsqb;</mo> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <mi>tan</mi> <mn>2</mn> <mi>&amp;theta;</mi> <mo>=</mo> <mfrac> <mrow> <mn>2</mn> <msub> <mi>U</mi> <mi>b</mi> </msub> <mo>-</mo> <msub> <mi>U</mi> <mi>a</mi> </msub> <mo>-</mo> <msub> <mi>U</mi> <mi>c</mi> </msub> </mrow> <mrow> <msub> <mi>U</mi> <mi>a</mi> </msub> <mo>-</mo> <msub> <mi>U</mi> <mi>c</mi> </msub> </mrow> </mfrac> </mrow> </mtd> </mtr> </mtable> </mfenced> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>1</mn> <mo>)</mo> </mrow> </mrow>
In formula:σ1Maximum principal stress in-cell cube, σ3Minimum principal stress in-cell cube, the compression strength of E-rock;R*— The radius of measured hole;Ua、Ub、UcShift value measured by-deformeter a, b, c;2 θ-determined according to tan2 θ calculated values;
5) the natural stress σ of rock mass is tried to achieve according to formula (2)Z
<mrow> <msub> <mi>&amp;sigma;</mi> <mi>z</mi> </msub> <mo>=</mo> <mfrac> <mn>1</mn> <mn>2</mn> </mfrac> <mrow> <mo>(</mo> <msub> <mi>&amp;sigma;</mi> <mn>1</mn> </msub> <mo>+</mo> <msub> <mi>&amp;sigma;</mi> <mn>3</mn> </msub> <mo>)</mo> </mrow> <mo>+</mo> <mfrac> <mn>1</mn> <mn>2</mn> </mfrac> <mrow> <mo>(</mo> <msub> <mi>&amp;sigma;</mi> <mn>1</mn> </msub> <mo>-</mo> <msub> <mi>&amp;sigma;</mi> <mn>3</mn> </msub> <mo>)</mo> </mrow> <mi>c</mi> <mi>o</mi> <mi>s</mi> <mn>2</mn> <mi>&amp;theta;</mi> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> <mo>.</mo> </mrow>
3. assay method as claimed in claim 1, it is characterised in that the physical and mechanical parameter of country rock includes in the second step Country rock internal friction angle parameterInternal friction angle parameter is equal to the reduction coefficient that sillar internal friction angle standard value is multiplied by setting, reduction system It is several to be determined according to cranny development degree.
4. assay method as claimed in claim 1, it is characterised in that the physical and mechanical parameter of country rock includes in the second step Country rock internal cohesion parameter c, internal cohesion parameter are multiplied by the reduction coefficient of setting by country rock internal cohesion standard value.
5. assay method as claimed in claim 1, it is characterised in that tunnel surrounding section plastic circle radius in the 3rd step R obtains according to formula (3):
In formula:R-tunnel plastic circle radius;Ro- relaxation zone radius, takes Ro=r, r-tunnel excavation radius of circle,In-country rock Rub angular dimensions.
6. assay method as claimed in claim 5, it is characterised in that tunnel is tried to achieve according to formula (4) in the 4th step and enclosed Rock pressure power σw
In formula:R-tunnel excavation radius of circle, σZThe natural stress of-Rock Mass, c-country rock internal cohesion parameter.
7. assay method as claimed in claim 1, it is characterised in that mixed with injection according to ground anchorage in the 5th step Native support engineering technical specification is coagulated, for the suitable 0.50m~1.00m of anchor pole spacing in IV, V grade of country rock, and cannot be greater than 1.25m, determine the horizontal spacing of adjacent two anchor poleAnd longitudinal pitch Sb
8. the assay method as described in claim 1 or 7, it is characterised in that in the 5th step, tried to achieve and added according to formula (5) Gu anchor pole radial direction prestress value fy
σw- Tunnel Surrounding Rock Pressure,The horizontal spacing of-adjacent two anchor pole, SbThe longitudinal pitch of-adjacent two anchor pole.
9. assay method as claimed in claim 8, it is characterised in that mixed with injection according to ground anchorage in the 6th step Native support engineering technical specification is coagulated, anchor rod anchored section of optimization length Δ l is calculated by formula (6):
<mrow> <mi>&amp;Delta;</mi> <mi>l</mi> <mo>=</mo> <mfrac> <mrow> <msub> <mi>Kf</mi> <mi>y</mi> </msub> </mrow> <mrow> <msub> <mi>n&amp;pi;d&amp;xi;f</mi> <mrow> <mi>m</mi> <mi>s</mi> </mrow> </msub> <mi>&amp;psi;</mi> </mrow> </mfrac> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>6</mn> <mo>)</mo> </mrow> </mrow>
In formula:D-anchorage body diameter;fmsUltimate bond stress between-anchoring body surface and surrounding Rock And Soil;K-anchor Solid bonds safety coefficient;The radical of n-reinforcing bar or steel strand wires;The adhesion strength at ξ-interface reduces coefficient, takes 0.7-0.85; Influence coefficient of the ψ-anchoring strength to adhesion strength.
10. the assay method as described in claim 1 or 9, it is characterised in that in the 6th step, tunnel reinforcement anchor pole is most Excellent design length L is calculated according to formula (7):
L=R-r+ Δs l (7)
Wherein, R-tunnel plastic circle radius;R-tunnel excavation radius of circle, anchor rod anchored section of optimization length Δ l.
CN201510767522.9A 2015-11-11 2015-11-11 The assay method of tunnel surrounding prestressed reinforcement rock-bolt length and radial direction prestress value CN105241510B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201510767522.9A CN105241510B (en) 2015-11-11 2015-11-11 The assay method of tunnel surrounding prestressed reinforcement rock-bolt length and radial direction prestress value

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201510767522.9A CN105241510B (en) 2015-11-11 2015-11-11 The assay method of tunnel surrounding prestressed reinforcement rock-bolt length and radial direction prestress value

Publications (2)

Publication Number Publication Date
CN105241510A CN105241510A (en) 2016-01-13
CN105241510B true CN105241510B (en) 2017-11-14

Family

ID=55039237

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201510767522.9A CN105241510B (en) 2015-11-11 2015-11-11 The assay method of tunnel surrounding prestressed reinforcement rock-bolt length and radial direction prestress value

Country Status (1)

Country Link
CN (1) CN105241510B (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107587891A (en) * 2017-08-07 2018-01-16 宁夏建设职业技术学院 A kind of coal mine roadway Design of bolt support method
CN108062436A (en) * 2017-12-04 2018-05-22 中国能源建设集团广东省电力设计研究院有限公司 The pull out force detection method and system of rock-bolt
CN108062439A (en) * 2017-12-08 2018-05-22 西安科技大学 Roadway support quantifying design method based on plastic zone of surrounding rock size
CN108005697B (en) * 2017-12-29 2020-08-11 中铁第四勘察设计院集团有限公司 Tunnel system anchor rod design method based on safety coefficient method
CN108222969B (en) * 2017-12-29 2019-11-05 中铁第四勘察设计院集团有限公司 A kind of Design of Tunnel method based on method of safety coefficients
CN109883779A (en) * 2019-01-21 2019-06-14 绍兴文理学院 Anchor structure face dimensional effect shearing test design method
CN109914242B (en) * 2019-03-18 2020-12-15 中国石油天然气集团有限公司 Method for anchoring main cable of combined tunnel anchor type large-span suspension cable pipeline bridge

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19914973A1 (en) * 1999-04-01 1999-11-18 Tachus Gmbh Process for determination of the earlier forces acting on an area or mountain or earth prior to boring of a tunnel or similar
CN103195453B (en) * 2013-04-16 2015-04-29 中国矿业大学 Parameter determination method for bolt supporting based on roadway bearing structure
CN104653196B (en) * 2015-01-30 2017-02-01 北京交通大学 Initial design method of tunnel engineering considering all-parameter influence
CN104899421A (en) * 2015-05-05 2015-09-09 兖州煤业股份有限公司 Roadway support parameter determining method and supporting method
CN104988918B (en) * 2015-07-24 2016-08-24 青岛理工大学 A kind of assay method of deep basal pit prestressed anchor optimum anchorage length

Also Published As

Publication number Publication date
CN105241510A (en) 2016-01-13

Similar Documents

Publication Publication Date Title
CN102606162B (en) Quick construction method for weak surrounding rock shallowly-buried easily-collapsed area of tunnel
Kang et al. Application of a combined support system to the weak floor reinforcement in deep underground coal mine
CN104790978B (en) The tunnel ring-shaped base tunnel construction method of small interval crossings on different level
CN101761346B (en) Method for constructing metamorphic rock confined water tunnel
CN201401174Y (en) System monitoring broken rock zone by high-density electrical resistivity
CN103198619B (en) Motive power monitoring and warning method of rock mass landslide
CN106285768B (en) CO2Directional blasting crack initiation couples anti-reflection gas pumping method with hydraulic fracturing
CN105401947B (en) The large deformation of high-ground stress Support System in Soft Rock Tunnels controls construction method
CN103344491B (en) Method for simulating roadway rock burst based on coaction of static load and blast load
CN105631102B (en) A kind of numerical simulation of deep high stress tunnel drilling relief parameter determines method
Jiang et al. Stability assessment of a high rock slope by strength reduction finite element method
CN105277993B (en) A kind of sea area Prospecting of Gold Deposits method
CN106499398B (en) Soft Rock Tunnel Excavation method based on rockbolt stress analysis
CN101922985B (en) Measurement method for stress change of rocks during TBM tunneling
CN106481343A (en) A kind of Soft Rock Tunnel Excavation and preliminary bracing method
Lee et al. Rock engineering in underground energy storage in Korea
Zhu et al. The characteristics of deformation and failure of coal seam floor due to mining in Xinmi coal field in China
CN103076119A (en) Method for measuring floor heave main control stress of laneway
CN104390733B (en) Determination method for magnitude and direction of crustal stress
CN102561330A (en) Integrated construction method for artificial dug pile and steel pipe concrete column
CN106245626A (en) A kind of hard formation churning driven enters method
CN107014603B (en) A kind of experimental method obtaining different geology operating condition shield cutter exciting forces
Bian et al. Cause investigation and verification of lining cracking of bifurcation tunnel at Huizhou Pumped Storage Power Station
CN103293560B (en) A kind of method of testing adopting triple stress court
CN105134219B (en) Soft rock strata freezing shaft borehole wall construction technology

Legal Events

Date Code Title Description
PB01 Publication
C06 Publication
SE01 Entry into force of request for substantive examination
C10 Entry into substantive examination
GR01 Patent grant
GR01 Patent grant