CN1556402A - Method of calculating and idontifying influence of temperature against deep part displacement using side slope rock body temerpature displace ment field - Google Patents

Abstract

The method includes following steps: boring deep holes on side slope of rock body; monitoring opening or deep part of rock body and drawing their displacement procedure lines and distributing lines of displacement along depth; determining thermodynamic parameters of rock body, boundary condition of temperature field at side slope; calculating quasi-stable temperature field and displacement field for side slope by equation of heat conduction; making displacement and temperature procedure lines and distributing lines of displacement along depth; comparing the said calculated lines with monitored lines determine whether temperature influences displacement at deep part of rock body, and how large the influence is. Thus, the invention can obtain regular rule of temperature and displacement fields.

Description

Utilize the slope rock mass temperature-displacement field to calculate the method for identification temperature to the deep displacement influence

Technical field

The invention belongs to the geology monitoring technology, be specifically related to a kind of slope rock mass temperature-displacement field that utilizes and calculate the method for identification temperature the deep displacement influence.

Background technology

In the stable safety monitoring on artificial side slope and natural landslide (hereinafter to be referred as slope, limit (cunning)), the deep displacement that generally adopts clinograph to measure the sloping rock mass in limit (cunning) at present changes.But, one of problem that puzzled for a long time people do not understand is, why after limit (cunning) slope excavation finishes, can aperture displacement-time course line with the tiltmeter actual measurement also constantly rise and fall in time? the very natural suspection temperature of people may be to influence the reason that horizontal shift rises and falls, it is the influence of temperature actually? is there there great influence? which type of rule does influence have? the open source literature record is not arranged at present as yet, in the stable safety monitoring on artificial side slope and natural landslide (hereinafter to be referred as slope, limit (cunning)), utilizing the slope rock mass temperature-displacement field to calculate the identification temperature influences deep displacement, to solve the influence relation of variation of temperature to the slope rock mass deep displacement of explaining.

Summary of the invention

The object of the present invention is to provide a kind of slope rock mass temperature-displacement field that utilizes to calculate the method for identification temperature, to address the above problem to the deep displacement influence.

Technical scheme of the present invention is: utilize the slope rock mass temperature-displacement field to calculate the method for identification temperature to the deep displacement influence: drilling deep hole on the side slope of rock mass, utilize clinograph but be not limited to the clinograph monitoring and draw the displacement graph in slope rock mass aperture and/or deep and/or displacement along the distributing line of the degree of depth; Collect or monitoring of environmental temperature and drafting thermograph; Collect or measure the thermodynamic parameter of slope rock mass; Determine the boundary condition in rock mass slope temperature field; Utilize heat-conduction equation to calculate the slope rock mass quasi stationary temperature field; Change the slope rock mass displacement field that causes according to the quasi stationary temperature field accounting temperature; Utilize temperature-displacement field result of calculation, put out the graph of displacement and temperature and displacement, temperature distribution curve in order, the slope rock mass displacement graph that temperature movement graph that relatively calculates and monitoring obtain along the degree of depth.By temperature, displacement graph and the temperature that calculates, displacement draws temperature-displacement field along the distribution curve of the degree of depth rule.

By temperature movement graph that relatively calculates and the slope rock mass displacement graph that monitoring obtains, judge whether variation of temperature is influential to the variation of slope rock mass deep displacement, influence has problems such as much.By temperature, displacement graph and the temperature that calculates, displacement draws temperature-displacement field along the distribution curve of the degree of depth rule.This scheme is that the inventor proposes in the stable safety monitoring on artificial side slope and natural landslide (hereinafter to be referred as slope, limit (cunning)) first.

Description of drawings

Fig. 1 is every He Yan power station CX240-1 measured displacements time course line

Fig. 2 is every He Yan power station actual measurement CX110-1 displacement time course line

Fig. 3 is every river rock factory building side slope I-I section and tiltmeter arrangenent diagram

Fig. 4 is every rock key water control project dam, river district temperature conditional curve

Fig. 5 slope displacement-temperature field computational grid figure

Fig. 6 240m aperture absolute displacement, thermograph

Fig. 7 210m aperture absolute displacement, thermograph

Fig. 8 150m aperture absolute displacement, thermograph

Fig. 9 128m aperture absolute displacement, thermograph

Figure 10 110m aperture absolute displacement, thermograph

Figure 11 100m aperture absolute displacement, thermograph

Figure 12 displacement-depth curve

Temperature under the high temperature of Figure 13-depth profile curve

Temperature-depth profile curve under the low temperature of Figure 14

Embodiment

As shown in Figure 3, we at its I-I section boring and layout tiltmeter, detect the displacement graph (as Fig. 1,2) of also drawing the slope rock mass aperture to be example every river rock factory building side slope, measure and draw temperature graph (as Fig. 4).

1, calculate principle:

Be in the rock mass slope under the temperature effect for a long time, any point temperature in the rock mass changes to make simple harmonic quantity with one-period, and its luffing and phase place are different with coordinate (being x, y under the two-dimensional case).By heat transfer theory, quasi stationary temperature field T (x, y) satisfies following heat-conduction equation in the side slope scope:

$\frac{\∂T}{\∂\mathrm{\τ}}=a(\frac{{\∂}^{2}T}{\∂x^2}+\frac{{\∂}^{2}T}{\∂y^2})+\frac{\∂\mathrm{\θ}}{\∂\mathrm{\τ}}----\left(1\right)$

And boundary value condition:

For first kind boundary condition, the Temperature Distribution on promptly known side slope surface then should satisfy

T=T ₀+ Asin ω τ (2) or

For the second class boundary condition, the heat flow density on promptly known side slope surface should satisfy when the surface is thermal insulation

$\frac{\∂T}{\∂n}=0----\left(3\right)$ Or

For third boundary condition, when promptly there is heat interchange on the side slope surface with surrounding medium, then should satisfy

$\mathrm{\λ}\frac{\∂T}{\∂x}{l}_x+\mathrm{\λ}\frac{\∂T}{\∂y}{l}_y+\mathrm{\β}(T-T_0)=0----\left(4\right)$

In the formula: T-temperature;

T ₀-be given border temperature;

τ-time;

θ-adiabatic temperature rise;

A=λ/c ρ-thermal diffusivity;

λ-coefficient of heat conductivity;

ρ-unit weight;

A-temperature luffing;

ω-temperature Change frequency;

β-surface heat transfer coefficient;

N-is the outer normal direction on border;

l _x, l _y-be the normal direction cosine on border;

X, y-are planimetric coordinates.

2, computing method:

We adopt two-dimensional finite element method to find the solution.

(1) computing grid and boundary value condition

Computing grid is given in Fig. 5, computer capacity shown in Figure 5 increases to some extent than the actual side slope scope that Fig. 1 provides, wherein 80m is all strengthened in left and right sides and bottom, purpose is to make relevant border to satisfy adiabatic condition, the boundary condition of side slope boundary condition and dam is not quite similar, there is not the situation of third boundary condition in the side slope here, and to Fig. 5 side slope each the section boundary condition is given is described as follows:

BC: be adiabatic face, free boundary;

CD: be adiabatic face, fixed boundary;

DE: be adiabatic face, can displacement along the y direction, but can not be along the displacement of x direction;

EF, FA, AB: be temperature boundary surface, free boundary.

Wherein x to: along aspect, "+" is direction displacement outside the slope

Y to: vertical to, "+" on lift.

(2) calculating parameter

Calculating parameter sees Table 1, and the various parameters in the table 1 provide according to the assembly average of the test determination value of relevant rock.

(3) the initial temperature condition provides temperature graph such as Fig. 4.Then under year temperature border effect, the initial temperature condition that the temperature when 1980 calculate 2000 is calculated as displacement.

(4) subregion (grey petrographic province and shale district) had been considered the different physical and mechanical parameters and the thermal property of rock mass during calculated in the temperature field, had considered the coefficient of heat emission on basement rock surface.

Table 1 calculates thermodynamic parameter every river rock factory building high slope temperature deformation

Rock	Coefficient of heat conductivity	Thermal diffusivity	Specific heat	Unit weight	Heat storage coefficient	Hot thermal expansivity	Play mould
								Unit	W/λ(m. ℃)	??M 2.a/h	????J/Kg. ????℃	??kg/m 3	????W/m 2.℃	???×10 -6/ ???℃	??Gpa
Limestone	2.92	??0.00449	????951.34	??2.65× ????10 3	????22.16	???8.36	??10
								Shale	2.24	??0.0032	????930	??2.55× ????10 3	????20.17	???7.0	??3

Computing method

In numerical solution, adopt implicit difference equation to the time backward difference.The temperature of arbitrary node with the shape function interpolation is in the unit: T ^e=[N] { T} ^e(5)

For unstable heat conduction problem, calculate in the temperature field need satisfy heat-conduction equation, starting condition and boundary condition.According to variational principle, its extreme-value problem that turns to functional is carried out the temperature field calculate, carry out obtaining implicit difference equation and find the solution this system of equations obtaining t+ Δ t temperature field constantly after the minimization.

Temperature stress and calculation of displacement are to adopt finite element method to calculate at times.

Looking basement rock is line elastomer, and the strain-stress relation of certain any arbitrary period is in the unit:

{Δσ}＝[D]·[{Δε}-{Δε ^T}]??????????????????(6)

In the formula: Δ σ-stress increment [D]-elastic matrix Δ ε-strain increment

{ Δ ε ^T}=α [Δ T, Δ T, Δ T, 0,0,0] ^TBe the temperature strain increment

Δ T-temperature increment

According to the principle of virtual work, each unit is obtained equation:

[k] ^e·{Δδ} ^e＝{ΔR} ^e??????????????????(7)

Wherein: ${\left[k\right]}^e=\underset{v}{\∫}{\left[B\right]}^T\·\left[D\right]\·\left[B\right]\mathrm{dv}$

${\left[\mathrm{\ΔR}\right]}^e=\underset{v}{\∫}{\left[B\right]}^T\·\left[D\right]\·\left\{\mathrm{\Δ}{\mathrm{\ϵ}}^T\right\}\mathrm{dv}$

[Δ δ] ^eBe unit node nodal displacement increment

Gather all unit, [K] { Δ δ }={ Δ R} (8) is then arranged

Solve { Δ δ } from (8) formula, superpose then, try to achieve total displacement.

3, result of calculation and comparison

Calculate according to temperature-displacement field, put out displacement and variation of temperature graph in order and along the curve of depth profile.

The face of land (being the tiltmeter drilling orifice) is subjected to having the greatest impact of temperature, existing with maximum temperature July each elevation aperture horizontal shift be given in Fig. 6-11 with the graph of temperature.

3.1 see that by Fig. 6-11 horizontal shift has following rule with temperature Change:

(1) temperature Change is influential to horizontal shift, but the amount of influence is very little.Influence to I-I section side slope (limestone and shale) displacement is the millimeter level, but the displacement variable of surveying with clinograph is centimetre-sized (Fig. 2～3); Find out that from the temperature movement Changing Pattern different with the actual measurement graph, it is to become simple harmonic curve to change in the cycle to see Fig. 6 and Figure 11 that temperature movement changed with the year, but the period of change of measured displacements and undulations and simple harmonic curve differ greatly all.As seen, temperature variation exists the influence of deep displacement, but is not main factor, necessarily has other factor main than influence of temperature change.

(2) horizontal shift varies with temperature to be periodically and changes, and period of change is consistent with year temperature Change cycle, and displacement and the temperature relation of being proportionate.

(3) increase (being that side slope is to sloping outer displacement) with temperature rising displacement, reduce displacement with temperature and reduce (being that side slope moves) in the mountain

(4) change in displacement and temperature variation are asynchronous, the variation of change in displacement temperature hysteresis, and retardation time is relevant with near the Slope Shape lithology, elevation and the position, and the shortest time that lags behind is about 35 days, occurs in the 240m aperture; About 75 days of hysteresis maximum duration occurs in the 128m aperture.Ash petrographic province about 35-60 retardation time days, about 50-75 days shale district retardation time.

3.2 the rule that displacement changes with drilling depth:

Provide displacement-change in depth curve at the bottom of the boring each point relative opening in Figure 12.See by Figure 12:

, increase displacement with the degree of depth and generally reduce during apart from the aperture degree of depth greater than 10m; In the degree of depth 10m of aperture, except that 240m boring, all there is a displacement to reduce process, have only the 240m full hole of holing to increase with hole depth, displacement reduces all the time, the reason that this placement property occurs, be since about the plain stage of slope at each boring place the different institute of the different temperature difference regularities of distribution that caused of the Slope Shape (or gradient) of (or about) cause.

3.3 the rule that temperature changes along drilling depth

Temperature is given in Figure 13～14 with the distribution curve of the degree of depth in each elevation deviational survey hole.See from figure:

(1) under the high temperature, in hole depth 7～11m scope, Kong Wen drops sharply to 16～16.5 ℃ earlier with the hole depth increase from aperture (face of land), increases with hole depth then, slowly is increased to 17 ℃ of equilibrium temperatures respectively.Promptly along hole depth sharply temperature drop is arranged earlier, the back is the process (referring to Figure 13) of temperature rise slowly.

(2) under the low temperature, in hole depth 7～11m scope, Kong Wen increases elder generation with hole depth and sharply rises to 17.3～17.8 ℃, increases with hole depth then, slowly drops to 17 ℃ of equilibrium temperatures respectively from aperture (face of land).Promptly along hole depth sharply temperature rise is earlier arranged, the back is the process (referring to Figure 14) of temperature drop slowly.

(3) influenced by temperature darker than the boring in the shale for the boring in the limestone; Boring near the temperature border is influenced than dark away from the boring on temperature border by temperature.

(4) be 8～10m for the degree of depth that influences, be no more than 1 ℃ greater than the variation of this degree of depth every river rock engineering factory building side slope I-I section slope rock mass.

4, conclusion:

By the temperature-displacement field every river rock diversion tunnel and factory building side slope I-I monitoring section slope rock mass is calculated, we can obtain following some conclusion:

(1) temperature Change is influential to the slope rock mass deep displacement, but temperature Change is less to the influence of slope displacement, and influence displacement and be the millimeter level, therefore, the other factors that physical presence is main than temperature effect.

(2) displacement is periodic variation with temperature Change, and its period of change is consistent with the temperature Change cycle, and displacement and the temperature Change relation of being proportionate.

(3) change in displacement lags behind temperature variation, to every He Yan power station I-I section slope rock mass being retardation time not wait in 35～75 days.

(4) temperature Change is relevant with slope excavating shape (or gradient) and lithology to the influence of the boring in the slope rock mass.Limestone and darker than the shale neutralization away from the boring on temperature border near the influence on temperature border.For I-I section slope rock mass, influence the about 11m of the degree of depth, be changed to about 1.0 ℃ greater than the temperature maximum of the 11m degree of depth.Therefore, generally be subjected to the influence of temperature Change only about 1.0 ℃ greater than the tiltmeter measuring point of 11m apart from the aperture degree of depth.

Claims (3)

1, utilize the slope rock mass temperature-displacement field to calculate the method for identification temperature to the deep displacement influence, its method is: drilling deep hole on the side slope of rock mass, utilize clinograph but be not limited to clinograph monitoring and draw the displacement graph in slope rock mass aperture and/or deep and displacement along the distributing line of the degree of depth; Collect or monitoring of environmental temperature and drafting thermograph; Collect or measure the thermodynamic parameter of slope rock mass; Determine the boundary condition in rock mass slope temperature field; Utilize heat-conduction equation to calculate the slope rock mass quasi stationary temperature field; Change the slope rock mass displacement field that causes according to the quasi stationary temperature field accounting temperature; Utilize temperature-displacement field result of calculation, put out the graph of displacement and temperature and displacement, temperature distribution curve in order, the slope rock mass displacement graph that temperature movement graph that relatively calculates and monitoring obtain along the degree of depth; Judge whether variation of temperature is influential to the slope rock mass deep displacement, by temperature, displacement graph and the temperature that calculates, displacement draws temperature-displacement field along the distribution curve of the degree of depth the regularity of distribution.

2, utilize the slope rock mass temperature-displacement field to calculate the method for identification temperature according to claim 1, it is characterized in that described heat-conduction equation is the deep displacement influence:

$\frac{\∂T}{\∂\mathrm{\τ}}=a(\frac{{\∂}^{2}T}{{\∂x}^2}+\frac{{\∂}^{2}T}{{\∂y}^2})+\frac{\∂\mathrm{\θ}}{\∂\mathrm{\τ}}---\left(1\right)$

Boundary condition is:

For first kind boundary condition, the Temperature Distribution on promptly known side slope surface then should satisfy

T=T ₀+ Asin ω τ (2) or for the second class boundary condition, the heat flow density on promptly known side slope surface is when the surface should be satisfied when adiabatic

$\frac{\∂T}{\∂n}=0---\left(3\right)$ Or, when promptly there is heat interchange on the side slope surface with surrounding medium, then should expire for third boundary condition

$\mathrm{\λ}\frac{\∂T}{\∂x}{l}_x+\mathrm{\λ}\frac{\∂T}{\∂y}{l}_y+\mathrm{\β}(T-T_0)=0---\left(4\right)$

In the formula: T-temperature;

T ₀-be given border temperature;

τ-time;

θ-adiabatic temperature rise;

α=λ/c ρ-thermal diffusivity;

λ-coefficient of heat conductivity;

ρ-unit weight;

A-temperature luffing;

ω-temperature Change frequency;

β-surface heat transfer coefficient;

N-is the outer normal direction on border;

l _x, l _y-be the normal direction cosine on border;

X, y-are planimetric coordinates.

3, utilize the slope rock mass temperature-displacement field to calculate the method for identification temperature according to claim 1, it is characterized in that finite element model for solving is adopted in the calculating of slope displacement field the deep displacement influence.

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