CN203346902U - Gravity type composite retaining wall with vertical prestressed anchor rod - Google Patents

Abstract

The utility model relates to a geotechnical engineering calamity prevention and cure technical field. The utility model discloses a compound barricade of vertical prestressed anchorage pole gravity type, including setting up the grout rubble wall body on the basement layer, grout rubble wall body, basement layer and open along same vertical direction and have the anchor eye, are equipped with the stock in the anchor eye, fill cement mortar between stock and the anchor eye, the top of anchor eye is equipped with the concrete anchor beam, and the concrete anchor beam is arranged in the upper end of starching the rubble wall body, is equipped with the concrete anchor head on the concrete anchor beam. The utility model discloses a compound barricade of vertical prestressed anchorage pole gravity type compares with traditional gravity type barricade, utilizes the elasticity of stock to return and to apply prestressing force to the wall body and not only can replace barricade masonry weight, reduces the cross-sectional dimension of barricade, reinforcing barricade wall body wholeness and shear strength.

Description

The compound barricade of vertical prestressing anchor pole gravity

Technical field

The utility model relates to geotechnical engineering diaster prevention and control technical field, be specifically related to integrated use prestressed anchor and the Gravity Retaining Wall antiskid loading characteristic that collapses, set up a kind of vertical prestressing anchor pole and the composite supporting construction method for designing of Gravity Retaining Wall and job practices of this structure of administering instable slope.

Background technology

Landslide is that a kind of distribution is very wide, endangers very large natural calamity.Develop rapidly along with economic construction, all can run into a large amount of slope project stability problems at engineering fields such as water conservancy and hydropower, railway, highway, mine constructions, slope reinforcement has become a common difficulties in China's infrastructure construction, therefore, the slope supporting prevention and cure project is the basic geotechnical engineering of slope project stability control, wherein, barricade is one of the most effective prevention and cure project generally adopted in slope reinforcement, retaining engineering now.

Barricade can be resisted lateral earth pressure because of it, prevent wall after Rock And Soil cave in, especially in Road-slope Project, to stablize embankment and cut slope, reduce the earth and rock works amount, prevent the current scour roadbed and be widely used.Barricade commonly used has Gravity Retaining Wall, weight formula barricade and Cantilever Retaining Wall.Gravity Retaining Wall mainly relies on the deadweight of barnacle bricklaying or cement concrete body of wall to resist the Rock And Soil lateral pressure to reach stability of slope; The gravity that weight formula barricade mainly utilizes weight platform top to banket, make after the body of wall center of gravity in-migration opposing soil body lateral pressure to reach stable side slope; Cantilever Retaining Wall mainly consists of base plate and the cantilevered stalk that is fixed on base plate, by the weight of banketing on base plate, maintains the stable of side slope.

For above traditional barricade: Gravity Retaining Wall is because its application of reason such as its deadweight, wall body stability against overturning are restricted, the body of wall quantity of masonry is large, the wall body is low, construction and self floor space are large, in the engineering of some particular restriction, need to be to the side slope side of being cut to reach the requirement of barricade wall body deadweight, like this can additionally increase engineering quantity and the control expense of slope treatment, simultaneously because reducing the possibility of anti-skid section increasing slope instability of side slope; Weight formula barricade adopts on weight platform top and bankets after making the body of wall center of gravity and move to resist soil pressure, its principle remains the concept of Gravity Retaining Wall, and weight platform bottom is concrete structure, increases to a certain extent expense (comprising cost of materials, labour cost, transport cost etc.), the difficulty of construction of slope project improvement and construct work day; Cantilever Retaining Wall adopts reinforced concrete wall, bankets in base plate toe of wall and wall heel, but all needs to arrange base plate before and after this wall body wall, thereby take up room to banket, to the requirement harshness in place.

Also derive the compound wall-retaining structure that barricade and other technology combine in side slope consolidation projects.Anchored bolt retaining wall is comprised of steel concrete metope and anchor pole, the anchor pole that dependence is anchored in rock stratum provides horizontal pull with opposing soil body lateral pressure, downward-sloping 10 °-15 ° of anchor pole mean level, for main primary structure member, but anchor pole must be anchored in the stable basement rock under the slope sliding face, anchor pole from the bottom of wall more away from, the length of material needed is longer, the exposed material of the anchor pole in side slope inside also can't guarantee its corrosion resistance, and design life also is difficult to guarantee.

As can be seen here, traditional barricade props up gear ruggedized construction, or is that toe is arranged to the space requirement of barricade is larger, that constructing operation is complicated and engineering cost is higher, be the extra side's of cutting disturbance slope stability, its weak point arranged, and for special place, limitation is all arranged.Therefore, on being collapsed in the loading characteristic basis in integrated use prestressed anchor and Gravity Retaining Wall antiskid, set up the composite supporting construction method for designing of a kind of vertical prestressing anchor pole and Gravity Retaining Wall, the deficiency of traditional slope retaining wall will be in the practice of harnessing of instable slope, overcome, and disaster reduction and prevention effect and the benefit of slope retaining wall can be given full play to.

The utility model content

Technique effect of the present utility model can overcome above-mentioned defect, provides a kind of vertical prestressing anchor pole gravity compound barricade, and gravity and floor space that it has greatly reduced the barricade body of wall, have the ability of well preventing and treating the side slope disaster.

For achieving the above object, the utility model adopts following technical scheme: it comprises the cemented rock body of wall be arranged on horizon d, cemented rock body of wall, horizon d have anchor hole along same vertical direction, be provided with anchor pole in anchor hole, filling concrete mortar between anchor pole and anchor hole, the top of anchor hole is provided with the concrete anchor beam, and the concrete anchor beam is placed in the upper end of cemented rock body of wall, and the concrete anchor beam is provided with the concrete anchor head.

The compound barricade of vertical prestressing anchor pole gravity of the present utility model, in support engineering of cutting slope, due to the restriction of Slope placement of foot construction space, under the condition that meets the barricade deadweight, traditional Gravity Retaining Wall is set, and construction space can not meet its wall section size, be under the reasons such as wall body thickness, the compound barricade of choice for use vertical prestressing anchor pole gravity, according to job practices, calculate the prestressing force size that need to apply to reach the barricade body of wall gravity that should compensate when barricade body of wall deadweight is not enough on vertical anchor pole, then carry out the side slope hazard management according to the anchoring construction principle of prestressed anchor.

Anchor hole is spaced along the highway direction.Anchor pole adopts high-strength fine rail screw-thread steel, and the part that anchor pole is placed in the cemented rock body of wall is free segment, and it twines the layers of asphalt glass-fiber-fabric, and outer cover twines pvc pipe.

Another purpose of the present utility model is to provide the job practices of the compound barricade of a kind of vertical prestressing anchor pole gravity, deficiency for above-mentioned traditional slope retaining wall, particularly for not putting the narrow and small slope of highway of slope and left and right construction space etc., the barricade limited space is set, adopt its construction plant of traditional Gravity Retaining Wall can not meet under the condition of traditional slope retaining wall design condition and requirement, the side slope compound support method that a kind of vertical prestressing anchor pole of special proposition combines with Gravity Retaining Wall.

The compound barricade design and construction of vertical prestressing anchor pole gravity of the present utility model method, comprise the steps:

Determining of the compound barricade basic parameter of (I) side slope gravity: according to Gravity Retaining Wall design specifications and side slope domatic to be administered, slope Gao, slope body thickness and place steric requirements, determine the compound barricade bottom width of prestressed anchor gravity B, end face width D and wall height H;

(II) location unwrapping wire and foundation trench excavation: according to the compound barricade basic parameter of side slope gravity, at the Slope placement of foot, retain the working face width, determine the bottom width of cemented rock body of wall, the toe place, along parallel highway direction lime unwrapping wire, marks the width of foundation trench excavation, and is excavated;

Determining of the prestressed anchor position of the compound barricade of (III) unit length and prestressing force size:

(1) be greater than while meeting the required prestressing force of antiskid the prestressing force F that anchor pole applies and the position Z of anchor pole when meeting the required prestressing force of overturning or slip resistance analysis _ffor:

$F=[\frac{B}{3}(K_0+1)Y_{E}E\cos \mathrm{\α}+\frac{B}{2}[\mathrm{\σ}]-(E\sin \mathrm{\α}+G)],$

$Z_F=\frac{K_{0}E\cos \mathrm{\α}{Y}_E-E\sin \mathrm{\αB}-{\mathrm{GZ}}_G}{\frac{B}{3}(K_0+1)Y_{E}E\cos \mathrm{\α}+\frac{B}{2}\left[\mathrm{\σ}\right]-(E\sin \mathrm{\α}+G)};$

(2) be greater than while meeting the required prestressing force of overturning or slip resistance analysis the prestressing force F that anchor pole applies and the position Z of anchor pole when meeting the required prestressing force of antiskid _ffor:

$F=\frac{{\mathrm{EK}}_c\cos \mathrm{\α}}{\mathrm{\μ}}-(E\sin \mathrm{\α}+G),$

$Z_F=\frac{K_{0}E\cos \mathrm{\α}{Y}_E-E\sin \mathrm{\αB}-G{Z}_G}{\frac{{\mathrm{EK}}_c\cos \mathrm{\α}}{\mathrm{\μ}}-E\sin \mathrm{\α}-G};$

Wherein, K ₀for barricade overturning or slip resistance analysis integral stability factor, K _cfor barricade along substrate Against Sliding Stability coefficient, the bottom width that B is barricade, Y _efor the height of Thrust application point to the barricade bottom, E is the Thrust on landslide, and G is the barricade deadweight, Z _gattach most importance to point of force application to the distance of toe of wall, and α is Thrust and horizontal angle, and [σ] is the substrate allowable bearing, and μ is the substrate friction factor;

(3) determining of compound barricade anchor rod prestress design load F ' and longitudinal pitch:

(a) the anchor rod prestress value is carried out to the safety factor correction; correcting method is according to the consequence of the importance of slope project and scale, slope instability and integrates the complexity composite factor; and determine Side Slope Safety Coefficient K ' according to industry standard; K '=1.30～1.35 wherein; get the safe correction factor of Side Slope Safety Coefficient K ' to be administered as anchor rod prestress; determine the compound barricade anchor rod prestress of unit length design load with this, i.e. F '=K ' * F;

(b), according to uplift resistance N ' and the compound barricade anchor rod prestress of the unit length design load F ' of anchor pole, determine the longitudinal pitch d of anchor pole:

$d=\frac{N^{\′}}{F^{\′}};$

(IV) armature boring and grout body of wall: holed by the position of above-mentioned prestressed anchor along the inboard of barricade at foundation trench excavate, after armature boring completes, after the piece stone of taking is nearby slightly done to polish, start to build by laying bricks or stones by cement mortar;

(V) inserts boring, the anchoring of being in the milk by anchor pole;

(VI) anchor rod prestress stretching and locking: when body of wall reaches design strength 100%, anchoring section intensity reaches 80%, after layers of concrete reaches 100% design strength, carry out the stretching and locking of prestressed anchor, guarantee that in stretching process body of wall is stressed evenly, adopting deformation joint is that unit implements the stretch-draw operation, anchor pole in each deformation joint section is carried out to stretch-draw simultaneously, unified command, the stretch-draw of every grade and final locking are controlled and are completed at one time, be pulled to and be greater than the anchor rod prestress design load at prestressing force, after stable, unload again pulling force to design load, after stable, fastening nut is locked, locked and with concrete, anchor head has been sealed afterwards.

This compound barricade by arranging the vertical prestressing anchor pole in existing barricade, and the anchoring prestress with prestress application on barricade compensates barricade weight, reduces barricade thickness, to meet structural support standard and the requirement of its barricade under above-mentioned engineering specifications.This barricade adopts the cemented rock body of wall of traditional Gravity Retaining Wall, anchor pole adopts high-strength fine rail screw-thread steel, and retaining wall foundation is placed among basement rock, and easy construction is quick, expense is cheap, because anchor pole can anchor among middle weathered rocks, anchor rod anchored high efficiency and good endurance, the prestressing force of anchor pole can increase the vertical force of barricade, strengthen barricade antiskid and resistance to capsizing, also can increase the stiction at Tu Yan interface, improve the stability of side slope, very applicable for the above-mentioned slope of highway of mentioning.

The concrete steps of its construction technology are as follows: 1) at the Slope placement of foot, carry out native stone and remove processing, improvement place vertical cut is the following 30cm of Slope Sliding face place to stablizing bedrock surface; 2), on the working face cleared, according to anchor pole position definite in the utility model step 3, excavate the vertical anchor hole of a row (comprising boring and clear hole); 3) the vertical vertical HRB335 screw-thread steel that inserts the φ 18-32 millimeter of choosing in anchor hole, and build the micro-expansion cement mortar and carry out anchoring section grouting; 4) masonry of cement mortar rubble barricade.Choose rubble around in the slope treatment district and build use by laying bricks or stones in order to barricade, use masonry of cement mortar to guarantee the globality of barricade, anchoring should be built by laying bricks or stones in rubble while building barricade by laying bricks or stones, choose the distance at body of wall edge by structural requirement; 5) lay ground tackle.After barricade has been built by laying bricks or stones, on the wall head piece, the anchoring extended position is placed ground tackle.6) prestressed anchor stretch-draw, and carry out free segment cement mortar perfusion in the anchor pole body of wall simultaneously; 7) when the cement mortar initial set, anti-tensile locking prestressed anchor.

Its process also can be described as:

Soil stone cleaning-→ boring-→ anchor pole is embedding-→ cast of prestressed anchor anchoring section-→ barricade builds by laying bricks or stones-→ the security protection ground tackle-→ stretch-draw prestressing force, free segment grouting-→ the anchoring locking.

The load acted in step (III) on the compound barricade of unit length vertical prestressing anchor pole gravity has: Thrust of Landslide Е, body of wall self gravitation G, prestressed load F and substrate frictional resistance f, and the horizontal thrust acted on barricade is:

In ∑ T=Ecos α formula, α is Thrust of Landslide position and horizontal angle;

The skid resistance acted on barricade is substrate frictional resistance, and it is:

∑ N=f=μ (Esin α+G+F), in formula, μ is the substrate friction factor;

The prestressing force F that in step (III), definite anchor pole applies and the position Z of anchor pole _fconcrete steps are as follows:

(1) stability against sliding of anchor pole Gravity Retaining Wall:

The whole antiskid of anchored bolt retaining wall moves stability calculation:

$K_c=\frac{\mathrm{\ΣN}}{\mathrm{\ΣT}}=\frac{\mathrm{\μ}(E\sin \mathrm{\α}+G+F)}{E\cos \mathrm{\α}},$

Can release from above formula the prestressing force F that unit length barricade prestressed anchor need apply

$F=\frac{E{K}_c\cos \mathrm{\α}}{\mathrm{\μ}}-(E\sin \mathrm{\α}+G);$

(2) overturning or slip resistance analysis of anchored bolt retaining wall is stable:

The whole overturning or slip resistance analysis stability calculation of vertical prestressed anchor pole spacing wall:

$K_0=\frac{E\sin \mathrm{\αB}+G{Z}_G+{\mathrm{FZ}}_F}{E\cos \mathrm{\α}{Y}_E},$

Can obtain the prestressing force F that unit length barricade prestressed anchor need to apply from above formula,

$F=\frac{K_{0}E\cos \mathrm{\α}{Y}_E-E\sin \mathrm{\αB}-{\mathrm{GZ}}_G}{Z_F},$ In formula, Z _ffor the distance of prestressing force to toe of wall;

(3) the barricade base pressure is calculated:

The point of resultant force of substrate:

$C=\frac{E\sin \mathrm{\αB}+G{Z}_G+{\mathrm{FZ}}_F-\mathrm{Ecox\α}{Y}_E}{E\sin \mathrm{\α}+G+F}$

Eccentric throw:

$e=\frac{B}{2}-C$

Substrate two edges point, the Normal compressive stress σ of toe and heel ₁, σ ₂be respectively:

$\begin{array}{c}{\mathrm{\σ}}_1\\ {\mathrm{\σ}}_2\end{array}=\frac{{\mathrm{\ΣN}}_1}{A}\±\frac{\mathrm{\ΣM}}{W}=\frac{G+F+E\sin \mathrm{\α}}{B}(1\±\frac{6e}{B});$

In formula: the moment sum of ∑ M-each power centering axle, ∑ M=∑ N ₁* e,

∑ N ₁-act on suprabasil total vertical force,

W-substrate section modulus, to the barricade of unit linear meter(lin.m.), W=B ²/ 6,

A-substrate section area, to the barricade of unit linear meter(lin.m.), A=B,

The basis compressed stress must not be greater than substrate allowable bearing [σ];

(4) design of anchor pole:

The bore position of anchor pole should arrange toward barricade is inboard under the prerequisite that meets substrate allowable bearing [σ], and prestressed anchor can provide maximum anchorage;

The calculating of bore position:

Wall heel place stress is σ to the maximum ₂should be less than or equal to substrate allowable bearing [σ], that is:

${\mathrm{\σ}}_2=\frac{G+F+E\sin \mathrm{\α}}{B}(1+\frac{6e}{B})\≤\left[\mathrm{\σ}\right],$

According to above-mentioned formula, draw in the situation that meet the bore position Z of maximum base pressure anchor pole _f:

$Z_F=\frac{1}{F}(\frac{B}{3}(E\sin \mathrm{\&alpha;}+G+F)-(E\sin \mathrm{\&alpha;B}+{\mathrm{GZ}}_G+Y_{E}E\cos \mathrm{\&alpha;})-\frac{{\mathrm{<figure-callout\; id="2"\; label="B"\; filenames="HDA00003505891100021.png,HDA00003505891100031.png"\; state="\{\{state\}\}">B</figure-callout>}}^2}{6}[\mathrm{\&sigma;}\left]\right)$

Can obtain:

$Z_F=\frac{K_{0}E\cos \mathrm{\&alpha;}{Y}_E-E\sin \mathrm{\&alpha;B}-{\mathrm{GZ}}_G}{\frac{B}{3}(K_0+1)Y_{E}E\cos \mathrm{\&alpha;}+\frac{B}{2}\left[\mathrm{\&sigma;}\right]-(E\sin \mathrm{\&alpha;}+G)},$

The requirement that now position of anchor pole can meet net foundation pressure can meet the requirement of overturning or slip resistance analysis again, and the anti-prestressing force that pushes away prestressed anchor and can provide is:

$F=[\frac{B}{3}(K_0+1)Y_{E}E\cos \mathrm{\&alpha;}+\frac{B}{2}[\mathrm{\&sigma;}]-(E\sin \mathrm{\&alpha;}+G)],$

Be greater than while meeting the required prestressing force of overturning or slip resistance analysis when meeting the required prestressing force of antiskid, recalculate the position of anchor pole:

$Z_F=\frac{K_{0}E\cos \mathrm{\&alpha;}{Y}_E-E\sin \mathrm{\&alpha;B}-G{Z}_G}{\frac{{\mathrm{EK}}_c\cos \mathrm{\&alpha;}}{\mathrm{\&mu;}}-E\sin \mathrm{\&alpha;}-G}.$

In step (III):

In step (b), pitch-row is greater than 20 times of bore diameters.

In step (b), during boring, must guarantee following condition:

(1) the anchor hole deviations must be less than 20mm, and the anchor hole degree of skewness must be less than 1%;

(2) drilling depth empties residual core in hole after completing, and the former clear hole again of anchoring section grouting is also rinsed boring;

(3) drilling depth surpasses rock-bolt length 500mm;

(4) after having holed, in aperture, reserved pvc pipe is to planning to build the barricade top, and barricade is afterwards built by laying bricks or stones along pvc pipe and reserved boring.

The vertical pvc pipe that will guarantee the hell plant in step (IV) in building process is vertical, and the pvc pipe diameter is greater than bar diameter 3-4mm, and length is got 1.2-1.5 times of cutting depth, and mouth of pipe sealing, in case cement paste flows into.

In step (V), the anchor pole that is positioned at the cemented rock body of wall is open die forging, and what be positioned at horizon d is anchoring section, anchoring section and free segment segmenting slip casting, and slurry adopts cement mortar, intensity M30; Anchoring section adopts the back-grouting technology, is normal pressure grouting for the first time, and at the bottom of the employing hole, the method perfusion, be in the milk for the second time and carry out after Grouting Cement mortar consolidating strength reaches 5.0MPa for the first time, grouting pressure 1.5-2MPa; Free segment perfusion maltha, heat into semi liquid state by pitch, then with pump, pitch sent in hole, and pitch overflows aperture naturally can be finished.

In sum, the compound barricade of vertical prestressing anchor pole gravity of the present utility model is compared with traditional Gravity Retaining Wall, utilize the elastical retraction of anchor pole to apply prestressing force to body of wall and not only can replace barricade bricklaying weight, reduce the sectional dimension of barricade, better be applicable to and overcome deficiency and the restriction of special construction site condition, can also strengthen barricade wall body globality and shear strength thereof, there is the bricklaying of the body of wall of saving simultaneously, gather materials on the spot, cheap, the advantage of easy construction and the minimizing toe side of cutting, greatly reduce the cost of quantity of masonry and slope treatment, also fully guaranteeing under the prerequisite of the unlikely destruction of side slope safety, make the slope retaining wall design reach optimum engineering control effect and rational economical plan.

The accompanying drawing explanation

Fig. 1 is the utility model vertical prestressed anchor pole spacing wall calculation diagram;

Fig. 2 is the utility model vertical prestressed anchor pole spacing wall construction schematic diagram;

Fig. 3 is the vertical sectional schematic diagram of the utility model vertical prestressed anchor pole spacing wall.

In figure: E is the Thrust on landslide; The deadweight that G is barricade; F is prestressed size; F is the substrate frictional resistance; The height that H is barricade; The bottom width that B is barricade; The upper width that D is barricade; Y _efor the height of Thrust application point to the barricade bottom; Z _gthe distance of point of force application to toe of wall of attaching most importance to; Z _ffor the distance of prestressing force to toe of wall; α is Thrust and horizontal angle.Wherein each unit of force is newton, and the unit of length is rice.

1-concrete anchor head; 2-concrete anchor beam; The 3-landslide is domatic; 4-cemented rock body of wall; The 5-slide plane; The 6-anchor pole; The 7-cement mortar; The 8-horizon d; The 9-anchor hole.

The specific embodiment

The compound barricade of vertical prestressing gravity of the present utility model, comprise the cemented rock body of wall 4 be arranged on horizon d 8, cemented rock body of wall 4, horizon d 8 have anchor hole 9 along same vertical direction, be provided with anchor pole 6 in anchor hole 9, filling concrete mortar 7 between anchor pole 6 and anchor hole 9, the top of anchor hole 9 is provided with concrete anchor beam 2, and concrete anchor beam 2 is placed in the upper end of cemented rock body of wall 4, and concrete anchor beam 2 is provided with concrete anchor head 1.

Anchor hole 9 is spaced along the highway direction.Anchor pole adopts high-strength fine rail screw-thread steel, and the part that anchor pole is placed in cemented rock body of wall 4 is free segment, and it twines the layers of asphalt glass-fiber-fabric, and outer cover twines the diameter pvc pipe.

Cemented rock body of wall 4 is arranged on the front end on landslide domatic 3, plays the effect stopped, can effectively prevent from coming down domatic 3 along geological disasters such as slide plane 5 generation landslides.

The job practices of the compound barricade of vertical prestressing gravity of the present utility model, the prestressing force size that main contents comprise the stretch-draw anchor of prestressed anchor and are applied to the anchor pole in the cemented rock body of wall, main construction course and step principle are as described below:

The main working procedure of the utility model comprises boring (boring, clear hole, anchoring section grouting), inserts anchor pole (installation), builds the sheet masonry stone by laying bricks or stones, lays ground tackle and stretching anchor rod, and its basic utility model step is as follows:

Step 1: the determining of the compound barricade basic parameter of side slope gravity

According to Gravity Retaining Wall design specifications and side slope domatic to be administered, slope Gao, slope body thickness and place steric requirements, determine the compound barricade bottom width of prestressed anchor gravity, end face width and wall height.

Step 2: location unwrapping wire and foundation trench excavation

According to the compound barricade basic parameter of side slope gravity, at the Slope placement of foot, retain suitable working face width, determine the bottom width of cemented rock body of wall, the toe place is along parallel highway direction lime unwrapping wire, the width of mark foundation trench excavation, the pedestrian's work of going forward side by side excavation.

Step 3: the determining of the prestressed anchor position of the compound barricade of unit length and prestressing force size

According to the design principles of the compound barricade of prestressed anchor gravity, should meet the stable condition of barricade antiskid, overturning or slip resistance analysis and substrate simultaneously, the definite prestressed size and location of the compound barricade of unit length of the utility model are as follows:

1) be greater than while meeting the required prestressing force of antiskid the prestressing force F that anchor pole applies and the position Z of anchor pole when meeting the required prestressing force of overturning or slip resistance analysis _ffor:

$F=[\frac{B}{3}(K_0+1)Y_{E}E\cos \mathrm{\&alpha;}+\frac{B}{2}[\mathrm{\&sigma;}]-(E\sin \mathrm{\&alpha;}+G)]$

$Z_F=\frac{K_{0}E\cos \mathrm{\&alpha;}{Y}_E-E\sin \mathrm{\&alpha;B}-{\mathrm{GZ}}_G}{\frac{B}{3}(K_0+1)Y_{E}E\cos \mathrm{\&alpha;}+\frac{B}{2}\left[\mathrm{\&sigma;}\right]-(E\sin \mathrm{\&alpha;}+G)}$

2) be greater than while meeting the required prestressing force of overturning or slip resistance analysis the prestressing force F that anchor pole applies and the position Z of anchor pole when meeting the required prestressing force of antiskid _ffor:

$F=\frac{{\mathrm{EK}}_c\cos \mathrm{\&alpha;}}{\mathrm{\&mu;}}-(E\sin \mathrm{\&alpha;}+G)$

$Z_F=\frac{K_{0}E\cos \mathrm{\&alpha;}{Y}_E-E\sin \mathrm{\&alpha;B}-G{Z}_G}{\frac{{\mathrm{EK}}_c\cos \mathrm{\&alpha;}}{\mathrm{\&mu;}}-E\sin \mathrm{\&alpha;}-G}$

Prestressing force F and anchor pole position Z _fconcrete derivation see the compound barricade design principle 4 of the utility model prestressed anchor: the design of anchor pole and Fig. 1, Fig. 2.

3) determining of compound barricade anchor rod prestress design load F ' and longitudinal pitch:

A), after considering that Gravity Retaining Wall grouts, in anchor pole is applied to prestressed process, the distortion of its barricade can cause prestressing force to produce a certain amount of loss in loading procedure, therefore, carry out the safety factor correction to the anchor rod prestress value.Correcting method is according to the consequence of the importance of slope project and scale, slope instability and integrates the composite factor such as complexity, and determines Side Slope Safety Coefficient K ' (K '=1.30～1.35) according to " Technique Code for Building Slope Engineering " (GB50330---2002).Get the safe correction factor of Side Slope Safety Coefficient K ' to be administered as anchor rod prestress, with this, determine the compound barricade anchor rod prestress of unit length design load, be i.e. F '=K ' * F.

B), according to uplift resistance N ' and the compound barricade anchor rod prestress of the unit length design load F ' of anchor pole, determine the longitudinal pitch d of anchor pole:

$d=\frac{N^{\&prime;}}{F^{\&prime;}}$

The funnel sizes that test forms when destroying according to resistance to plucking, and bolthole is overstocked causes stress in rock stratum to concentrate in order to avoid, pitch-row should be greater than 20 times of bore diameters.In experimental project, the normal hole interval adopted is more than 1 meter.

The aperture of anchor pole is mainly determined by the required prestressing force applied of anchor pole and execution conditions, and in rock foundation, aperture is generally 50 millimeter.

Step 4: armature boring and grout body of wall

At the foundation trench excavated, along the inboard of barricade, by the position of above-mentioned prestressed anchor, holed.Must guarantee following condition during boring:

(1) the anchor hole deviations must be less than 20mm, and the anchor hole degree of skewness must be less than 1%;

(2) drilling depth empties residual core in hole after completing, and the former clear hole again of anchoring section grouting is also rinsed boring;

(3) drilling depth surpasses rock-bolt length 500mm.

(4) after having holed, in aperture, reserved pvc pipe is to planning to build the barricade top, and barricade is afterwards built by laying bricks or stones and can be reserved boring along pvc pipe, does not need body of wall is holed again.

After armature boring completes, after the piece stone of taking is nearby slightly done to polishing, by cement mortar, start to build by laying bricks or stones.The vertical pvc pipe that will guarantee the hell plant in building process is vertical, and the pvc pipe diameter should be greater than bar diameter 3-4mm, and length is got 1.2-1.5 times of cutting depth, and mouth of pipe sealing, in case cement paste flows into.

Step 5: anchor pole is made

Anchor pole adopts high-strength fine rail screw-thread steel, and the anchor rod body spreading adopts socket wrench specially adapted for it to connect, and the steel of sleeve should be identical with the body of rod.Free segment twines 2 layers of pitch glass-fiber-fabrics, and outer cover twines diameter 40mmPVC pipe; Anchor head adopts thread anchorage, and nut, nut all adopt the type the same with the body of rod with the steel of connector.

Step 6: the grouting anchoring of anchor pole

Grout stop is set, anchoring section and free segment segmenting slip casting, slurry adopts cement mortar, intensity M30; Anchoring section adopts the back-grouting technology, is normal pressure grouting for the first time, and at the bottom of the employing hole, the method perfusion, be in the milk for the second time and carry out after Grouting Cement mortar consolidating strength reaches 5.0MPa for the first time, grouting pressure 1.5-2MPa; Free segment perfusion maltha, heat into semi liquid state by pitch, then with pump, pitch sent in hole, and pitch overflows aperture naturally can be finished.

Step 7: anchor rod prestress stretching and locking.

Reach 80% when body of wall reaches design strength 100%, anchoring section intensity, after layers of concrete reaches 100% design strength, carry out the stretching and locking of prestressed anchor.Guarantee that in stretching process body of wall is stressed evenly, adopting deformation joint is that unit implements the stretch-draw operation, the anchor pole in each deformation joint section is carried out to stretch-draw simultaneously, unified command, and the stretch-draw of every grade and final locking basic controlling complete at one time.Be pulled to and be a bit larger tham the anchor rod prestress design load at prestressing force, after stablizing 5 minutes, then unload pulling force to design load, stable rear fastening nut is locked.Locked and with the C30 concrete, anchor head has been sealed afterwards.

The compound barricade design principle of the utility model vertical prestressing anchor pole gravity is as follows:

The load acted on the compound barricade of unit length vertical prestressing anchor pole gravity has: Thrust of Landslide Е, body of wall self gravitation G, prestressed load F and substrate frictional resistance f(are shown in Fig. 1).

The horizontal thrust acted on barricade is:

∑T=Ecosα （1）

In formula, α is Thrust of Landslide position and horizontal angle.

The skid resistance acted on barricade is that substrate frictional resistance is:

∑N=f=μ(Esinα+G+F) （2）

In formula, μ is the substrate friction factor, and the DIFFERENT SOIL layer can be chosen by Code for design of building table 6.7.5-2 the substrate friction factor of barricade, in particular cases can determine by on-the-spot friction test.

1, the stability against sliding of anchor pole Gravity Retaining Wall

The whole antiskid of anchored bolt retaining wall moves stability calculation:

$K_c=\frac{\mathrm{\&Sigma;N}}{\mathrm{\&Sigma;T}}=\frac{\mathrm{\&mu;}(E\sin \mathrm{\&alpha;}+G+F)}{E\cos \mathrm{\&alpha;}}---\left(3\right)$

In formula, K _c, choose according to " Code for design of building " GB50007-2011 regulation along substrate Against Sliding Stability coefficient for barricade, generally get 1.3.

Can find out from (3) formula, work as K _cone regularly, and the substrate frictional resistance that the prestressed load that the vertical prestressing anchor pole provides can improve barricade carrys out the Thrust on balance landslide, thereby reach balancing gravity formula barricade, because of cross section, reduces the problem that causes gravity deficiency.

Can release from formula (3) the prestressing force F that unit length barricade prestressed anchor need apply

$F=\frac{E{K}_c\cos \mathrm{\&alpha;}}{\mathrm{\&mu;}}-(E\sin \mathrm{\&alpha;}+G)---\left(4\right)$

2, the overturning or slip resistance analysis of anchored bolt retaining wall is stable

The whole overturning or slip resistance analysis stability calculation of vertical prestressed anchor pole spacing wall:

$K_0=\frac{E\sin \mathrm{\&alpha;B}+G{Z}_G+{\mathrm{FZ}}_F}{E\cos \mathrm{\&alpha;}{Y}_E}---\left(5\right)$

In formula, K ₀for barricade overturning or slip resistance analysis integral stability factor, according to " Code for design of building " GB50007-2011 regulation, choose, generally get 1.6, other symbolic significances are shown in figure (1).

Can find out that from formula (5) prestressed load that the vertical prestressing anchor pole provides has increased the whole stability against overturning of barricade.

Can obtain the prestressing force F that unit length barricade prestressed anchor need to apply from formula (5)

$F=\frac{K_{0}E\cos \mathrm{\&alpha;}{Y}_E-E\sin \mathrm{\&alpha;B}-{\mathrm{GZ}}_G}{Z_F}---\left(6\right)$

3, the barricade base pressure is calculated

The point of resultant force of substrate:

$C=\frac{E\sin \mathrm{\&alpha;B}+G{Z}_G+{\mathrm{FZ}}_F-\mathrm{Ecox\&alpha;}{Y}_E}{E\sin \mathrm{\&alpha;}+G+F}---\left(7\right)$

Eccentric throw:

$e=\frac{B}{2}-C---\left(8\right)$

The eccentric throw that substrate is made a concerted effort, earthen foundation should not be greater than B/10, and rock foundation should not be greater than B/4.

Substrate two edges point, i.e. the Normal compressive stress σ of toe and heel ₁, σ ₂be respectively:

$\begin{array}{c}{\mathrm{\&sigma;}}_1\\ {\mathrm{\&sigma;}}_2\end{array}=\frac{{\mathrm{\&Sigma;N}}_1}{A}\&PlusMinus;\frac{\mathrm{\&Sigma;M}}{W}=\frac{G+F+E\sin \mathrm{\&alpha;}}{B}(1\&PlusMinus;\frac{6e}{B})---\left(9\right)$

In formula: the moment sum of ∑ M-each power centering axle, ∑ M=∑ N ₁* e;

∑ N ₁-act on suprabasil total vertical force.

W-substrate section modulus, to the barricade of unit linear meter(lin.m.), W=B ²/ 6;

A-substrate section area, to the barricade of unit linear meter(lin.m.), A=B.

The basis compressed stress must not be greater than substrate allowable bearing [σ], and when considering main power system and the combination of additional force system, bearing capacity of foundation soil can improve 20%.

4, the design of anchor pole

The bore position of anchor pole should be tried one's best and be arranged toward barricade is inboard under the prerequisite that meets substrate allowable bearing [σ], and prestressed anchor can provide maximum anchorage.

The calculating of bore position:

Wall heel place stress is σ to the maximum ₂should be less than or equal to substrate allowable bearing [σ], that is:

${\mathrm{\&sigma;}}_2=\frac{G+F+E\sin \mathrm{\&alpha;}}{B}(1+\frac{6e}{B})\&le;\left[\mathrm{\&sigma;}\right]---\left(10\right)$

According to (7), (8), (9), (10) formula, draw in the situation that meet the bore position Z of maximum base pressure anchor pole _f:

$Z_F=\frac{1}{F}(\frac{B}{3}(E\sin \mathrm{\&alpha;}+G+F)-(E\sin \mathrm{\&alpha;B}+{\mathrm{GZ}}_G+Y_{E}E\cos \mathrm{\&alpha;})-\frac{{\mathrm{<figure-callout\; id="2"\; label="B"\; filenames="HDA00003505891100021.png,HDA00003505891100031.png"\; state="\{\{state\}\}">B</figure-callout>}}^2}{6}[\mathrm{\&sigma;}\left]\right)---\left(11\right)$

Wushu (6) is brought formula (11) into and can be obtained:

$Z_F=\frac{K_{0}E\cos \mathrm{\&alpha;}{Y}_E-E\sin \mathrm{\&alpha;B}-{\mathrm{GZ}}_G}{\frac{B}{3}(K_0+1)Y_{E}E\cos \mathrm{\&alpha;}+\frac{B}{2}\left[\mathrm{\&sigma;}\right]-(E\sin \mathrm{\&alpha;}+G)}---\left(12\right)$

The requirement that now position of anchor pole can meet net foundation pressure can meet the requirement of overturning or slip resistance analysis again, and the anti-prestressing force that pushes away prestressed anchor and can provide is:

$F=[\frac{B}{3}(K_0+1)Y_{E}E\cos \mathrm{\&alpha;}+\frac{B}{2}[\mathrm{\&sigma;}]-(E\sin \mathrm{\&alpha;}+G)]---\left(13\right)$

The material of anchor pole should be selected high-strength fine rule screw-thread steel, according to larger prestressing force in (4) and (13) formula, chooses anchor pole, when the prestressing force in (4) formula is greater than (13) formula, (4) formula should be brought into to the position that (6) formula recalculates anchor pole:

$Z_F=\frac{K_{0}E\cos \mathrm{\&alpha;}{Y}_E-E\sin \mathrm{\&alpha;B}-G{Z}_G}{\frac{{\mathrm{EK}}_c\cos \mathrm{\&alpha;}}{\mathrm{\&mu;}}-E\sin \mathrm{\&alpha;}-G}---\left(14\right)$

Anchor pole at bedrock surface place stress undue concentration and cut off, require under bedrock surface the organic cementitious material pitch of perfusion in certain limit, so the anchorage depth of anchor pole should be from counting below pitch under the horizontal thrust effect when preventing that barricade is subjected to displacement.

Apply prestressed load on common barricade after, effectively increased globality and the shear resistance of body of wall itself.In the tensile region of barricade, prestressed anchor has played again the effect of tensile reinforcement.

Claims (3)

1. the compound barricade of vertical prestressing anchor pole gravity, comprise the cemented rock body of wall (4) be arranged on horizon d (8), it is characterized in that, cemented rock body of wall (4), horizon d (8) have anchor hole (9) along same vertical direction, be provided with anchor pole (6) in anchor hole (9), filling concrete mortar (7) between anchor pole (6) and anchor hole (9), the top of anchor hole (9) is provided with concrete anchor beam (2), concrete anchor beam (2) is placed in the upper end of cemented rock body of wall (4), and concrete anchor beam (2) is provided with concrete anchor head (1).

2. the compound barricade of vertical prestressing anchor pole gravity according to claim 1, is characterized in that, anchor hole (9) is spaced along the highway direction.

3. the compound barricade of vertical prestressing anchor pole gravity according to claim 1, it is characterized in that, anchor pole adopts high-strength fine rail screw-thread steel, and the part that anchor pole is placed in cemented rock body of wall (4) is free segment, and after free segment twines the layers of asphalt glass-fiber-fabric, outer cover twines pvc pipe.

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