CN104833593A - Surrounding rock creep rupture warning method applied in soft rock cavern warning system - Google Patents

Abstract

The invention discloses a surrounding rock creep rupture warning method applied in a soft rock cavern warning system. The method is characterized by comprising following steps: (1) reading the stress [sigma] and the strain [epsilon] of surrounding rock in a soft rock cavern (represented as the drawing 1) through a sensor; (2) reading the pre-stored data of a triaxial compression test and a triaxial creep test of a rock sample of the soft rock cavern in which the soft rock cavern warning system is arranged for obtaining physical and mechanical parameters of the soft rock, including: bonding force c, internal friction angle [phi], and Poisson ratio [mu] and stress-strain curve data of a whole triaxial creep process under any stress state being higher than long-period strength; and (3) combining the test curve, obtained through the test, of the whole triaxial creep process under the stress state with the physical and mechanical parameters obtained in the step (2).

Description

Be applied to the Rock Creep damage alarm method of country rock cavern early warning system

Technical field

The present invention relates to a kind of Rock Creep damage alarm method being applied to soft rock hole early warning system.This technology is mainly by theory setting up creep of soft rock constitutive equation based on interior, the size of computational prediction soft rock tertiary creep value, there is the overall process of moment and creep thereof, for tunnel security maintenance provides guidance, and in conjunction with actual conditions, reduced equation is proposed, be easy to be engaged in the numerous designers of underground engineering field and engineering technical personnel understand, grasp, and in addition flexible Application.The proposition of this technology, the moment can destroyed for country rock generation creep rupture and tertiary creep during current country rock cavern excavation, coal excavation tunnel, goaf and operation thereof provides computational prediction more accurately, compensate for the blank of specification.Belong to underground engineering construction and later stage operation to the security implication of engineering itself and Protective strategy field.

Background technology

The creep properties of rock is one of important mechanical characteristic of rock, and a lot of rock engineerings all has substantial connection with the creep of rock.Especially the buried cavern in underground, tunnel and goaf, unstability and destruction are not complete at excavation or occur immediately after Practical Completion, stable rock mass is presented at the beginning of cavitation, pass distortion development in time, after some time, hole body possibility unstability or fall damage, the obvious characteristic that country rock has growth in time and is slowly out of shape, the creeping characteristic of buried soft rock is especially obvious, and secondary creep amount may considerably beyond instantaneous deformation amount.The creep of soft rock brings new challenge to the utilization of China's Deep Underground Space and exploitation, becomes one of the Major Difficulties of underground engineering structure design, Construction control; And underground works, seepage environment complicated in Tunnel Engineering, long duration load periodicity (repeatability) further increase the complicacy that creep studies.Also do not consider this factor of creep in current specification, make to design the deformation allowance adopted and be not often inconsistent with actual conditions, more do not predict for the carrying out in tertiary creep destruction moment, very difficult formulation not only economy but also the maintenance scheme of safety.Therefore, for tunnel excavation process and later maintenance, the research of creep rupture is particularly important.

The most frequently used most effective method at present by setting up rational constitutive model to describe, predicting the process of creep, Xiyuan Model uses the widest creep constitutive model at present, but it cannot the failure stage of simulation accelerated creep, the Xiyuan Model that a lot of scholar started to propose correction in recent years increases the simulation in tertiary creep stage.How the acceleration of creep deformation stage is differentiated also there is dispute with modeling effort, what current major part obtained is all empirical formula, and cannot reflect soft rock intrinsic propesties, theoretical research is inadequate, the a lot of experiment that even needs had could obtain its this structure formula, is difficult to promote the use of.Therefore, in actual underground works, be difficult to the moment that prediction soft rock generation tertiary creep destroys.

This technology proposes a kind of creep constitutive model of simple, strong operability on the basis of creep of soft rock mechanism theory research, quick and precisely can predict size, the time of origin of soft rock tunnel tertiary creep value.First, theory can set up creep of rock constitutive relation equation based on interior, and the triaxial creepage measured by indoor Three axis creep test under any a certain stress state of rock destroys the Complete Curve; Secondly, adopt least square method, carry out matching obtain constitutive model basic parameter in conjunction with constitutive equation to curve, program selects D-P series yield criteria and flow rule to set up three-dimensional constitutive model automatically; Then, the creep rupture curve of secondary development UMAT subroutine simulation under different stress of ABAQUS software programming is utilized; Finally, the stress state in conjunction with actual country rock adopts size and the time of Creep Equation computing method prediction soft rock tertiary creep value, and guiding construction design, security maintenance control.

Summary of the invention

Goal of the invention: the object of the present invention is to provide a kind of Rock Creep damage alarm method being applied to soft rock hole early warning system.

Technical scheme: the Rock Creep damage alarm method being applied to soft rock hole early warning system of the present invention, comprises the following steps:

1) described soft rock hole early warning system reads stress σ and the strain stress of monitoring point in the country rock of soft rock hole by sensor;

2) triaxial compression test of the rock sample in the soft rock hole at the early warning system place, described soft rock hole of reading pre-stored and Three axis creep test data, thus obtain the physical and mechanical parameter of described soft rock: cohesive force c, angle of internal friction and Poisson ratio μ and higher than the triaxial creepage overall process stress-strain curve data under arbitrary stress state of long-term strength;

3) Binding experiment obtain stress state under triaxial creepage overall process empirical curve and step 2) experiment obtain physical and mechanical parameter, adopt least square method, set up experiment strain value and constitutive equation (4), (5), (6) the strain error objective function of strain value is calculated, the program of simplicial method optimization method establishment is adopted to ask the minimum value of objective function, thus determine constitutive equation (4), (5) the unknown parameter E, in (6) ₀, E ₁, η ₁, η ₂, η ₃, obtain the Creep Equation of this rock.

$\left\{\mathrm{\ϵ}\left(t\right)\right\}=(\frac{1}{E_0}+\frac{1}{E_1^{\′}})\left[A\right]\left\{\mathrm{\σ}\right\},\stackrel{\‾}{\mathrm{\σ}}\≤{\stackrel{\‾}{\mathrm{\σ}}}_{s-\mathrm{long}}---\left(4\right)$

$\left\{\mathrm{\ϵ}\left(t\right)\right\}=(\frac{1}{E_0}+\frac{1}{E_1^{\′}})\left[A\right]\left\{\mathrm{\σ}\right\}+{\mathrm{\η}}_2\·\⟨\frac{F}{{\stackrel{\‾}{\mathrm{\σ}}}_0}\⟩\·\left\{m\right\}\·t,\stackrel{\‾}{\mathrm{\σ}}>{\stackrel{\‾}{\mathrm{\σ}}}_{s-\mathrm{long}}$ And ${\mathrm{\Γ}}_{\mathrm{ca}}^{{\mathrm{vp}}^{*}}>W\≥{\mathrm{\Γ}}_c^{{\mathrm{vp}}^{*}}---\left(5\right)$

$\left\{\mathrm{\ϵ}\left(t\right)\right\}=(\frac{1}{E_0}+\frac{1}{E_1^{\′}})\left[A\right]\left\{\mathrm{\σ}\right\}+{\mathrm{\η}}_2^{\′}\·\⟨\frac{F}{{\stackrel{\‾}{\mathrm{\σ}}}_0}\⟩\·\left\{m\right\}\·{\mathrm{\τ}}_2+{\mathrm{\η}}_2^{\′}\·{\mathrm{\η}}_3^{\′}\·{(t-{\mathrm{\τ}}_2)}^{\left(\frac{F}{{\stackrel{\‾}{\mathrm{\σ}}}_0}\right)}\·\⟨\frac{F}{{\stackrel{\‾}{\mathrm{\σ}}}_0}\mathrm{\σ\σ}\⟩\·\left\{m\right\}\·t,W\≥{\mathrm{\Γ}}_{\mathrm{ca}}^{{\mathrm{vp}}^{*}}---\left(6\right)$

Wherein, E ₀, E ₁, η ₁, η ₂, η ₃for Creep Equation parameter, obtain by a certain tertiary creep empirical curve matching; σ is principle stress; ε is overall strain; σ _s-longfor long-term strength (being obtained by Three axis creep test); for σ _s-longthe strain value that tertiary creep initial time desirable under condition is corresponding; for crossing yield-stress ratio; T is creep T.T., τ ₀for tertiary creep generation initial time, yield strength calculated value corresponding under bringing the expression three-dimensional situation of line, F represents yield function; for non-zero constant rate creeep critical strain energy density value; for tertiary creep critical strain energy density value; W is strain energy density value;

$E_1^{\′}=\frac{E_1}{1-\exp (-\frac{E_1}{{\mathrm{\η}}_1^{\′}}t)};\left\{m\right\}=\frac{\∂F}{\∂\mathrm{\σ}}$ For creep strain flow direction;

$\left[A\right]=\left[\begin{array}{cccccc}1& -\mathrm{\μ}& -\mathrm{\μ}& 0& 0& 0\\ -\mathrm{\μ}& 1& -\mathrm{\μ}& 0& 0& 0\\ -\mathrm{\μ}& -\mathrm{\μ}& 1& 0& 0& 0\\ 0& 0& 0& 2(1+\mathrm{\μ})& 0& 0\\ 0& 0& 0& 0& 2(1+\mathrm{\μ})& 0\\ 0& 0& 0& 0& 0& 2(1+\mathrm{\μ})\end{array}\right]$

4) adopt field measurement strain-stress curve to the parameter (E in the constitutive equation obtained ₀, E ₁, η ₁, η ₂, η ₃) carry out revising { the same step 3) of method, just step 3) in laboratory experiment strain-stress curve change the measured curve at scene into, obtain the Creep Equation of actual rock, thus under prediction different designs, arrangement and method for construction there is moment τ in tertiary creep _pif the tertiary creep destruction generation moment of prediction does not meet design requirement, i.e. τ _p>=τ ₀(τ ₀for moment controlling value occurs in the tertiary creep allowed), then send alarm signal, return step 1) carry out design proposal improvement.

Compared with prior art, its beneficial effect is in the present invention:

(1) propose the computing method of a kind of new physical mechanics clear concept, prediction country rock cavern country rock tertiary creep time of origin that is simple to operate, that easily grasp for numerous engineering technical personnel and designer and creep compliance thereof, compensate for the domestic blank about cavern con struction design specifications.

(2) the method is from the mechanism of interior energy angle analysis soft rock generation creep, meet soft rock strain feature, based on strain energy theory, Perzyna visco-plastic theory is adopted to combine with western former positive husband's component models, establish a kind of creep sand stone concrete that can describe soft rock weakening creeping, steady creep and tertiary creep three phases overall process, and the Creep Mechanics behavior of non-zero body strain can be described.

(3) the tertiary creep generation moment predicted can not only reflect the impact that accumulation creep strain damages, and effectively can reflect the impact of stress state on tertiary creep, more tally with the actual situation, possibility is provided for realizing the tertiary creep of prediction soft rock, and experimental quantities can greatly reduce, for practice provides conveniently, also increase along with experimental quantities increases precision of prediction, can carry out according to the different design stage such as primary design, job design feature substep, there is the engineer applied being very easy to promote and be worth.

Accompanying drawing explanation

Fig. 1 is a certain stress state schematic diagram in sandstone deep cavern vault district;

Fig. 2 is Three axis creep test curve and constitutive model fitting curve;

Fig. 3 is Three axis creep test curve and ABAQUS simulation and forecast curve;

Fig. 4 is the triaxial creepage damage curve under prediction different stress;

Embodiment

Below technical solution of the present invention is described in detail, but protection scope of the present invention is not limited to described embodiment.

Embodiment 1:

The present embodiment occurs based on interior energy theoretical research creep process, development mechanism, sets up the operation valve value calculating method of Creep Mechanics behavior sudden change and concrete equation; For the concrete soft rock of Practical Project, obtain the tertiary creep of soft rock under any a certain confined pressure according to indoor Three axis creep test and destroy the Complete Curve, adopt least square method, determine corresponding constitutive parameter, comprise D-P series yield criteria coefficient and corresponding flow rule, set up three-dimensional constitutive model; Then the creep rupture process of ABAQUS software secondary development UMAT subroutine simulation and forecast under different stress is utilized, tertiary creep time of origin under effective prediction country rock different parts different stress and creep compliance thereof, can control to provide reference for engineering safety accordingly, process in time, form a kind of creep of soft rock destruct limit new technology of practicality, Guiding Practice.

For deep cavern or goaf, when different depth, the stress state of cavern's vault can increase with buried depth, for same country rock, calculate different creep processes and tertiary creep generation possibility time thereof, in advance according to a small amount of creep test data, can predict that its different tertiary creep moment guiding construction supporting or later maintenance control to same country rock, and according to creep compliance difference, for the design of amendment deformation allowance makes reference.

Get a certain stress state in sandstone deep cavern vault district, this stress state is axle pressure 61MPa, confined pressure 6MPa, the rock Three axis creep test machine of the miniature control of RLM-2000 is adopted to carry out creep test to this type of sandstone, adopt least square method, matching obtains corresponding constitutive parameter, the physical and mechanical parameter of rock and fitting parameter are in table 1, Fig. 1 is a certain stress state in sandstone deep cavern vault district, Fig. 2 is the creep Parameters of constitutive model adopting least square method to obtain this rock, Fig. 3 works out constitutive equation subroutine for utilizing ABAQUS software secondary development UMAT subroutine platform, the creep rupture conditional curve of simulation and forecast under this stress state, analog result and actual conditions basically identical.

Table 1 constitutive model calculating parameter

When under actual measurement axial compression 61MPa, moment (τ occurs in tertiary creep ₀=36.2h) tertiary creep strain energy density value be 0.169J/m ³.There is moment (τ in prediction axial compression 61MPa tertiary creep ₀=36.0h) basically identical with measured data.

Excavation hole shape, get hole edge stress state, based on above-mentioned Constitutive Models in Predicting different buried depth (during corresponding different stress) Rock Creep amount, creep process, there is the possibility time in tertiary creep, Fig. 4 is prediction confined pressure 6MPa, the creep rupture conditional curve under axially different stress state.The creep rupture overall process under various stress state can be predicted according to the method, can effectively guiding construction design.

As shown in Figure 1, the present invention, first in conjunction with the finite element numerical model that the design phase can set up, calculates the stress state in vault district; As shown in Figure 2, by the stress state calculated, in conjunction with indoor Three axis creep test, obtain the Three axis creep test curve of country rock under a certain stress state, on the basis of creep test curve and soft rock physical and mechanical parameter, adopt least square method, select respective flow rule, matching obtains corresponding constitutive parameter; Then as shown in Figure 3, utilize the ABAQUS software secondary development UMAT subroutine platform establishment constitutive equation Fortran subroutine developed, the creep rupture conditional curve of simulation and forecast under this stress state, the accuracy of checking constitutive model, obtain size and the time of soft rock tertiary creep value simultaneously, calculate tertiary creep critical strain energy density in creep rupture process last as shown in Figure 4, by effectively can predict soft rock of the same race Rock Creep amount, creep process when different buried depth (during corresponding different stress) based on above-mentioned constitutive model, tertiary creep occurs may the guiding construction design such as time.

Simplification practical one dimension creep constitutive model based on the interior tertiary creep process that can describe that can be theoretical is as follows:

$\mathrm{\ϵ}\left(t\right)=\frac{\mathrm{\σ}}{E_0}+\frac{\mathrm{\σ}}{E_1}[1-\exp (-\frac{E_1}{{\mathrm{\η}}_1}t)],\stackrel{\‾}{\mathrm{\σ}}\≤{\stackrel{\‾}{\mathrm{\σ}}}_{s-\mathrm{long}}---\left(1\right)$

$\mathrm{\&epsiv;}\left(t\right)=\frac{\mathrm{\&sigma;}}{E_0}+\frac{\text{\&sigma;}}{E_1^{\&prime;}}[1-\exp (-\frac{E_1}{{\mathrm{\&eta;}}_1}t)]+{\mathrm{\&eta;}}_2\&CenterDot;\&lang;\frac{\mathrm{\&sigma;}}{{\mathrm{\&sigma;}}_0}\&rang;\&CenterDot;t,\mathrm{\&sigma;}>{\mathrm{\&sigma;}}_{s-\mathrm{long}}$ And $\mathrm{\&sigma;}\&CenterDot;\mathrm{\&epsiv;}<{\mathrm{\&sigma;}}_{s-\mathrm{long}}\&CenterDot;{\mathrm{\&epsiv;}}_s^{\mathrm{ap}}---\left(2\right)$

$\mathrm{\&epsiv;}\left(t\right)=\frac{\mathrm{\&sigma;}}{E_0}+\frac{\text{\&sigma;}}{E_1^{\&prime;}}[1-\exp (-\frac{E_1}{{\mathrm{\&eta;}}_1}t)]+{\mathrm{\&eta;}}_2^{\&prime;}\&CenterDot;\&lang;\frac{\mathrm{\&sigma;}}{{\mathrm{\&sigma;}}_0}\&rang;\&CenterDot;{\mathrm{\&tau;}}_0+{\mathrm{\&eta;}}_2\&CenterDot;{\mathrm{\&eta;}}_3\&CenterDot;\&lang;\frac{\mathrm{\&sigma;}}{{\mathrm{\&sigma;}}_0}\&rang;\&CenterDot;{(t-{\mathrm{\&tau;}}_0)}^{\frac{\mathrm{\&sigma;}}{{\mathrm{\&sigma;}}_0}}\&CenterDot;t$

σ > σ _s-longand $\mathrm{\&sigma;}\&CenterDot;\mathrm{\&epsiv;}\&GreaterEqual;{\mathrm{\&sigma;}}_{s-\mathrm{long}}\&CenterDot;{\mathrm{\&epsiv;}}_s^{\mathrm{ap}}---\left(3\right)$

Wherein, E ₀, E ₁, η ₁, η ₂, η ₃for Creep Equation parameter, obtain by a certain tertiary creep empirical curve matching; σ is principle stress; ε is overall strain; σ _s-longlong-term strength; for σ _s-longthe strain value that tertiary creep initial time desirable under condition is corresponding; for crossing yield-stress ratio; T is creep T.T., τ ₀for tertiary creep generation initial time.

It is as follows that one dimensional constitutive equations is rewritten into three-dimensional matrice form:

$\left\{\mathrm{\&epsiv;}\left(t\right)\right\}=(\frac{1}{E_0}+\frac{1}{E_1^{\&prime;}})\left[A\right]\left\{\mathrm{\&sigma;}\right\},\stackrel{\&OverBar;}{\mathrm{\&sigma;}}\&le;{\stackrel{\&OverBar;}{\mathrm{\&sigma;}}}_{s-\mathrm{long}}---\left(4\right)$

$\left\{\mathrm{\&epsiv;}\left(t\right)\right\}=(\frac{1}{E_0}+\frac{1}{E_1^{\&prime;}})\left[A\right]\left\{\mathrm{\&sigma;}\right\}+{\mathrm{\&eta;}}_2\&CenterDot;\&lang;\frac{F}{{\stackrel{\&OverBar;}{\mathrm{\&sigma;}}}_0}\&rang;\&CenterDot;\left\{m\right\}\&CenterDot;t,\stackrel{\&OverBar;}{\mathrm{\&sigma;}}>{\stackrel{\&OverBar;}{\mathrm{\&sigma;}}}_{s-\mathrm{long}}$ And ${\mathrm{\&Gamma;}}_{\mathrm{ca}}^{{\mathrm{vp}}^{*}}>W\&GreaterEqual;{\mathrm{\&Gamma;}}_c^{{\mathrm{vp}}^{*}}---\left(5\right)$

$\left\{\mathrm{\&epsiv;}\left(t\right)\right\}=(\frac{1}{E_0}+\frac{1}{E_1^{\&prime;}})\left[A\right]\left\{\mathrm{\&sigma;}\right\}+{\mathrm{\&eta;}}_2^{\&prime;}\&CenterDot;\&lang;\frac{F}{{\stackrel{\&OverBar;}{\mathrm{\&sigma;}}}_0}\&rang;\&CenterDot;\left\{m\right\}\&CenterDot;{\mathrm{\&tau;}}_2+{\mathrm{\&eta;}}_2^{\&prime;}\&CenterDot;{\mathrm{\&eta;}}_3^{\&prime;}\&CenterDot;{(t-{\mathrm{\&tau;}}_2)}^{\left(\frac{F}{{\stackrel{\&OverBar;}{\mathrm{\&sigma;}}}_0}\right)}\&CenterDot;\&lang;\frac{F}{{\stackrel{\&OverBar;}{\mathrm{\&sigma;}}}_0}\mathrm{\&sigma;\&sigma;}\&rang;\&CenterDot;\left\{m\right\}\&CenterDot;t,W\&GreaterEqual;{\mathrm{\&Gamma;}}_{\mathrm{ca}}^{{\mathrm{vp}}^{*}}---\left(6\right)$

Wherein: yield strength calculated value corresponding under bringing the expression three-dimensional situation of line, F represents yield function; for non-zero constant rate creeep critical strain energy density value; for tertiary creep critical strain energy density value; W is strain energy density value.

$E_1^{\&prime;}=\frac{E_1}{1-\exp (-\frac{E_1}{{\mathrm{\&eta;}}_1^{\&prime;}}t)};\left\{m\right\}=\frac{\&PartialD;F}{\&PartialD;\mathrm{\&sigma;}}$ For creep strain flow direction.

$\left[A\right]=\left[\begin{array}{cccccc}1& -\mathrm{\&mu;}& -\mathrm{\&mu;}& 0& 0& 0\\ -\mathrm{\&mu;}& 1& -\mathrm{\&mu;}& 0& 0& 0\\ -\mathrm{\&mu;}& -\mathrm{\&mu;}& 1& 0& 0& 0\\ 0& 0& 0& 2(1+\mathrm{\&mu;})& 0& 0\\ 0& 0& 0& 0& 2(1+\mathrm{\&mu;})& 0\\ 0& 0& 0& 0& 0& 2(1+\mathrm{\&mu;})\end{array}\right]$

As mentioned above, although represented with reference to specific preferred embodiment and described the present invention, it shall not be construed as the restriction to the present invention self.Under the spirit and scope of the present invention prerequisite not departing from claims definition, various change can be made in the form and details to it.

Claims (1)

1. be applied to a Rock Creep damage alarm method for country rock cavern early warning system, it is characterized in that, comprise the following steps:

1) described soft rock hole early warning system reads stress σ and the strain stress of monitoring point in the country rock of soft rock hole by sensor;

2) triaxial compression test of the rock sample in the soft rock hole at the early warning system place, described soft rock hole of reading pre-stored and Three axis creep test data, thus obtain the physical and mechanical parameter of described soft rock: cohesive force c, angle of internal friction and Poisson ratio μ and at arbitrary stress higher than (σ > σ under the state of long-term strength _s-long) triaxial creepage overall process stress-strain curve data;

3) Binding experiment obtain stress state under triaxial creepage overall process empirical curve and step 2) experiment obtain physical and mechanical parameter, adopt least square method, set up experiment strain value and constitutive equation (4), (5), (6) the strain error objective function of strain value is calculated, the program of simplicial method optimization method establishment is adopted to ask the minimum value of objective function, thus determine constitutive equation (4), (5) the unknown parameter E, in (6) ₀, E ₁, η ₁, η ₂, η ₃, obtain the Creep Equation of this rock.

and

Wherein, E ₀, E ₁, η ₁, η ₂, η ₃for Creep Equation parameter, be respectively: elastic modulus (GPa), viscoelastic modulus (GPa), elastomeric viscous coefficient (GPah), visco-plasticity coefficient of viscosity (GPah)-1, tertiary creep viscous correction coefficient; These unknown parameters adopt least square fitting to obtain by a certain tertiary creep empirical curve; σ is principle stress; ε is overall strain; σ _s-longfor long-term strength (being obtained by Chen Shi hierarchical loading Three axis creep test); for σ _s-longthe strain value that tertiary creep initial time desirable under condition is corresponding; for crossing yield-stress ratio; T is creep T.T., τ ₀for tertiary creep generation initial time corresponding on tertiary creep empirical curve; Adopt corresponding yield strength calculated value under bringing the expression three-dimensional situation of line, F represents yield function; for non-zero constant rate creeep critical strain energy density value, calculated by tertiary creep experimentation curve and obtain; for tertiary creep critical strain energy density value, calculated by tertiary creep experimentation curve and obtain; W is strain energy density value;

for creep strain flow direction;

4) adopt field measurement strain-stress curve to the parameter (E in the constitutive equation obtained ₀, E ₁, η ₁, η ₂, η ₃) revise.In conjunction with on-the-spot measured curve and step 2) test the physical and mechanical parameter obtained, adopt least square method, set up experiment strain value and constitutive equation (4), (5), (6) calculate the strain error objective function of strain value, adopt the program of simplicial method optimization method establishment to ask the minimum value of objective function, thus determine constitutive equation (4), (5) the unknown parameter E, in (6) ₀, E ₁, η ₁, η ₂, η ₃, obtain the Creep Equation of actual rock mass, thus under prediction different designs, arrangement and method for construction there is moment τ in tertiary creep _pif the tertiary creep destruction generation moment of prediction does not meet design requirement, i.e. τ _p>=τ ₀, τ ₀for moment controlling value occurs in the tertiary creep of the permission preset, usually with engineering design tenure of use for controlling value, then send alarm signal, otherwise return step 1).