CN102409638B - Low water resistance anchoring piece - Google Patents

Abstract

The invention provides a low water resistance anchoring piece, which comprises an anchor rod and an anchor head. The invention relates to a concrete anchoring piece, in particular to low water resistance anchoring equipment for temporary structures in hydraulic engineering and belongs to the field of hydraulic engineering construction. An upper half part of a buttock line of the anchor head is an elliptic curve, and the ratio of a short axis to a long axis of the elliptic curve is 0.5 to 0.6. The anchoring piece has lower water resistance, and can be used for constructing temporary spillways, particularly for fixing geotextile during emergency rescue.

Description

A kind of low water drag power anchoring piece

Technical field

A kind of low water drag power of the present invention anchoring piece relates to a kind of concrete anchor, and especially a kind of anchoring device than low water drag power of having for the hydraulic engineering temporary construction belongs to the water conservancy project building field.

Background technology

Anchoring usually is used for hydraulic architecture underground chamber, the ground of various hydraulic structures, the reinforcing of various types of side slopes in hydraulic engineering, and to the reinforcing of various hydraulic structures, the prestressing force gate pier that bears high hydraulic thrust and hydraulic tunnel ring anchor pre-stress lining anchor Design, construction and prestress anchoraging engineering.Anchoring its essence is and changes country rock or earth stress state, increases confined pressure, thereby improves the mechanics parameter of rock, changes by the mechanical property of Bolted Rock Masses, the soil body.Mostly existing anchoring piece is to design from soil mechanics, rock mechanics angle.For the emergent flood spillway erosion control material anchoring piece that the present invention relates to, because anchoring piece will be subjected to the high flow rate current and directly dash effect in the top, must consider the reasonability of its structure build from the hydraulics angle, consider that so far the rational emergent flood spillway erosion control material anchoring piece of hydraulics build do not see that as yet report is arranged.The erosion control material anchoring piece that the present invention relates to is with the difference of general anchoring piece maximum: the anchor head operated by rotary motion of erosion control material anchoring piece is in water environment, and the direct top that is subjected to the high flow rate current dashes, the anchor pole operated by rotary motion is in the more weak medium of soil layer or adhesion stress, work progress does not need boring, the modes of ramming that adopt more, therefore require this type of anchoring piece to reduce impact force of water flow, the anchor pole of avoiding ramming is deviate from because of water flow impact pressure as far as possible; And the anchor head operated by rotary motion of general anchoring piece is in air, the anchor pole operated by rotary motion runs through severely-weathered layer and weak weathered layer in rock stratum or the soil body, will realize the fixing of anchor by boring when construction, therefore require this type of anchoring piece to have strong anchored force, anchor head is avoided weathering.

Summary of the invention

The purpose of this invention is to provide a kind of low water drag power anchoring piece, current are reduced to minimum to the top impulse force of anchor head, this anchoring piece is mainly used in the fixing of erosion control material, is arranged in the water.

A kind of low water drag power anchoring piece comprises anchor pole and anchor head, it is characterized in that comprising: the first half of described anchor head buttocks is elliptic curve; The short major axis ratio of above-mentioned elliptic curve is 0.5～0.6.Draw through numerical simulation, the above-mentioned resistance of vertical section elliptic curve in water is less than rectangle, less than circular curve.

Above-mentioned anchor head center is provided with three holes, and anchor pole is trident, passes three holes of anchor head and is the state of immersing oneself at anchor head.Three holes that arrange are for supporting with anchor pole, be connected because the anchoring purpose is generally the fixture that adhesion stresss such as the moving object of light weight and the soil body is loose, so the anchored force of its single anchor are lower, can improve anchored force with the design of many anchor poles.

The ring set that links before and after above-mentioned anchor head is provided with, this type of anchoring piece are through being usually used in continuous anchoring, and the ring set that links before and after therefore arranging helps the overall fixed of continuous anchor body.

The tenon of overlap joint before and after above-mentioned anchor head is provided with, effect and the ring set of tenon are similar.

Beneficial effect of the present invention is:

1, provides a kind of brand-new low water drag power anchoring piece;

2, this type of anchoring piece can be used for the construction of interim flood spillway, fixing geotextile when being particularly useful for emergency repair.

Description of drawings

Fig. 1 has the low water drag power anchoring piece schematic side view of ring set;

Fig. 2 has the low water drag power anchoring piece side-looking platoon schematic diagram of ring set;

Fig. 3 has the low water drag power anchoring piece of ring set and overlooks the platoon schematic diagram;

Fig. 4 has the low water drag power anchoring piece schematic side view of tenon;

Fig. 5 has the low water drag power anchoring piece side-looking platoon schematic diagram of tenon;

Fig. 6 has the low water drag power anchoring piece of tenon and overlooks the platoon schematic diagram;

Fig. 7 is used for constructing the low water drag power anchoring piece schematic diagram of interim flood spillway.

The specific embodiment

Embodiment one

A kind of emergent flood spillway erosion control material low water drag power anchoring piece is seen Fig. 1, Fig. 4, comprises anchor pole 1 and anchor head 2, and it is characterized in that comprising: the first half of described anchor head 2 buttocks is elliptic curve; The short major axis ratio of above-mentioned elliptic curve is 0.5～0.6.Draw through numerical simulation, under the equal conditions, the above-mentioned resistance of vertical section elliptic curve in water is less than rectangle, and result of calculation sees Table 1.

Numerical simulation adopts the Three-dimensional Turbulent Flow Mathematical Modeling, and equal continuity equation and the equation of momentum when governing equation comprises, turbulent fluctuation can equation (K equation) and turbulent fluctuation energy dissipative shock wave equations (ε equation), and concrete form is as follows:

Continuity equation: $\frac{\∂\mathrm{\ρ}}{\∂t}+\frac{\∂\left(\mathrm{\ρu}\right)}{\∂x}+\frac{\∂\left(\mathrm{\ρw}\right)}{\∂z}=0$

The equation of momentum:

$\frac{\∂\left(\mathrm{\ρu}\right)}{\∂t}+\frac{\∂\left(\mathrm{\ρuu}\right)}{\∂x}+\frac{\∂\left(\mathrm{\ρuw}\right)}{\∂z}=\frac{\∂}{\∂x}(\mathrm{\μ}\frac{\∂u}{\∂x}-\stackrel{\‾}{{\mathrm{\ρu}}^{\′}{u}^{\′}})+\frac{\∂}{\∂z}(\mathrm{\μ}\frac{\∂u}{\∂u}-\stackrel{\‾}{{\mathrm{\ρu}}^{\′}{w}^{\′}})-\frac{\∂p}{\∂x}+S_w$

$\frac{\∂\left(\mathrm{\ρw}\right)}{\∂t}+\frac{\∂\left(\mathrm{\ρwu}\right)}{\∂x}+\frac{\∂\left(\mathrm{\ρww}\right)}{\∂z}=\frac{\∂}{\∂x}(\mathrm{\μ}\frac{\∂w}{\∂x}-\stackrel{\‾}{{\mathrm{\ρu}}^{\′}{w}^{\′}})+\frac{\∂}{\∂z}(\mathrm{\μ}\frac{\∂w}{\∂u}-\stackrel{\‾}{{\mathrm{\ρu}}^{\′}{w}^{\′}})-\frac{\∂p}{\∂x}+S_w$

The K equation: $\frac{\∂\left(\mathrm{\ρk}\right)}{\∂t}+\frac{\∂\left(\mathrm{\ρ}{\mathrm{ku}}_i\right)}{{\∂x}_i}=\frac{\∂}{{\∂x}_j}\left[(\mathrm{\μ}+\frac{{\mathrm{\μ}}_t}{{\mathrm{\δ}}_k})\frac{\∂k}{{\∂x}_j}\right]+G_k+G_b-\mathrm{\ρ\ϵ}-Y_M+S_k$

The ε equation: $\frac{\&PartialD;\left(\mathrm{\&rho;\&epsiv;}\right)}{\&PartialD;t}+\frac{\&PartialD;\left({\mathrm{\&rho;\&epsiv;u}}_i\right)}{{\&PartialD;x}_i}=\frac{\&PartialD;}{{\&PartialD;x}_j}\left[(\mathrm{\&mu;}+\frac{{\mathrm{\&mu;}}_t}{{\mathrm{\&delta;}}_k})\frac{\&PartialD;\mathrm{\&epsiv;}}{{\&PartialD;x}_j}\right]+{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000088516200000011.png"\; state="\{\{state\}\}">C</figure-callout>}}_{1\mathrm{\&epsiv;}}+\frac{\mathrm{\&epsiv;}}{k}-(G_k+{\mathrm{<figure-callout\; id="3"\; label="C"\; filenames="HDA0000088516200000011.png"\; state="\{\{state\}\}">C</figure-callout>}}_{3\mathrm{\&epsiv;}}{G}_b)-C_{2\mathrm{\&epsiv;}}\mathrm{\&rho;}\frac{{\mathrm{\&epsiv;}}_2}{k}+S_{\mathrm{\&epsiv;}}$

In standard k～ε turbulent flow model, according to relevant scholar's experimental verification, suggestion model constants C _{1 ε}, C _{2 ε}, C _{3 ε}, C _ε, C _μ, δ _k, δ _εValue be:

C _1ε＝1.44，C _2ε＝1.92，C _3ε＝0，C _μ＝0.99，δ _k＝1.0，δ _ε＝1.3

Under the same terms, be subjected to flow action to carry out numerical simulation to the anchoring block, calculate and adopt the Three-dimensional Turbulent Flow model, the fluid table adopts the VOF method to handle, adopt k～ε turbulent flow model to seal equation group, the wall function method of the mobile employing standard of near wall, the pressure-speed coupling is found the solution and is adopted the PISO algorithm, the time step 0.001s that adopts, the required time step is set at 50000, greatest iteration calculation times in each time step is 20, considers residual error less than 10e-6 and stable, thinks that calculating restrains.Flow resistance is the active force parallel with coming flow path direction that flows and to produce with the borderline phase mutual effect, for the border, drag direction with flow to identical, for current, drag direction with come flow path direction opposite.Be in a fixed object in flowing, this body surface forms mobile inner boundary.Get a small area dA on the boundary face, fluid acts on the dA face by shearing stress τ ₀And normal stress p ₀, therefore the shear force that acts on the dA is τ ₀DA, pressure are p ₀DA, if the regulation flow direction is the x direction, u ₀Be the component of incoming flow in the x direction, then shear force and pressure being projected as at flow direction:

dFx＝τ ₀dAcos（τ ₀,u ₀)+p ₀dAcos（p ₀,u ₀) （1）

To whole boundary face integrations, the expression formula that gets resistance is:

$\mathrm{Fx}=\underset{A}{\&Integral;}{\mathrm{\&tau;}}_0\cos ({\mathrm{\&tau;}}_0,u_0)\mathrm{dA}+\underset{A}{\&Integral;}{p}_0\cos (p_0,u_0)\mathrm{dA}---\left(2\right)$

As can be seen from the above equation, flow resistance comprises two parts: the frictional resistance that is caused by shearing stress and the pressure resistance that is formed by normal stress.

The resistance to water-flow of the different anchoring pieces of table 1

	The rectangle anchoring piece	The dome-type anchoring piece	The spheroid shape anchoring piece
				Along water (flow) direction resistance (N)	1392	1769	1170
Area (m 2）	0.1	0.138	0.1
				Flow velocity (m/s)	1.47	2.35	2.41
Resistance coefficient	12.85	4.64	4.03

Table 1 shows that the resistance coefficient of rectangle anchoring piece is three times of other two kinds of concrete anchors, and the size of dome-type and spheroid shape anchoring piece is comparatively approaching, and the spheroid shape resistance to water-flow is littler.In order to simplify the calculating of required anchored force, suppose that drill rod inserts at the middle part of anchoring piece, under current and weight effect, anchoring piece is along downstream and the domatic contact point destruction of toppling, along the moment size of contact point, result of calculation is as shown in table 2 under flow action for the calculating object:

The required anchored force of table 2 difformity anchoring piece is calculated

	The rectangle anchoring piece	The dome-type anchoring piece	The ellipsoid anchoring piece
				Structure bottom and domatic contact point moment (Nm)	283.5	260.6	223.3
Need anchored force (N)	268.4	274.1	44.7

Calculate the required anchored force minimum of demonstration ellipsoid anchoring piece, namely under square one, the ellipsoid anchoring piece is partial to safety.

Above-mentioned anchor head 2 centers are provided with three holes, and anchor pole is trident, pass three holes of anchor head and are the state of immersing oneself at anchor head.Three holes that arrange are for supporting with anchor pole, be connected because the anchoring purpose is generally the fixture that adhesion stresss such as the moving object of light weight and the soil body is loose, so the anchored force of its single anchor are lower, can improve anchored force with the design of many anchor poles.The ring set 3 that links before and after above-mentioned anchor head is provided with, this type of anchoring piece is seen Fig. 2,3,5,6,7 through being usually used in continuous anchoring, the ring set that links before and after therefore arranging helps the overall fixed of continuous anchor body.

Embodiment two

A kind of emergent flood spillway erosion control material low water drag power anchoring piece comprises anchor pole 1 and anchor head 2, and it is characterized in that comprising: the first half of described anchor head buttocks is elliptic curve; The short major axis ratio of above-mentioned elliptic curve is 0.5～0.6.

The tenon of overlap joint before and after above-mentioned anchor head is provided with, the effect of tenon is identical with ring set.

Claims (5)

1. a low water drag power anchoring piece comprises anchor pole and anchor head, it is characterized in that comprising: the first half of described anchor head buttocks is elliptic curve; The short major axis ratio of described elliptic curve is 0.5～0.6, and the surface area of spheroid shape anchoring piece is 0.1m ²

2. a kind of low water drag power anchoring piece according to claim 1 is characterized in that described anchor head center is provided with three holes.

3. a kind of low water drag power anchoring piece according to claim 1 is characterized in that described anchor pole is trident, passes three holes of anchor head and is the state of immersing oneself at anchor head.

4. according to the arbitrary described a kind of low water drag power anchoring piece of claim 1～3, it is characterized in that the ring set that links before and after described anchor head is provided with.

5. according to the arbitrary described a kind of low water drag power anchoring piece of claim 1～3, it is characterized in that the step of overlap joint before and after described anchor head is provided with.

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