CN101886362B - Structure method for expansion joint of cement concrete pavement - Google Patents

Abstract

A cement concrete pavement expansion joint construction method in the field of building construction technology. First, meteorological investigation and geological survey are carried out on the construction site to determine the temperature load and the geological conditions of the subgrade; then determine the construction parameters of the ground anchor; and after laying the pavement cushion , carry out ground anchor construction; then determine the horizontal anchorage length c of the end of the reinforced hanging bar around the ground anchor, the horizontal width b of the lower end of the hanging bar according to the design code for reinforced concrete structures, and arrange the reinforced hanging bar net at the row-shaped ground anchor, and the hanging bar net It is welded and connected with the distributed steel bars in the cement concrete pavement; finally, the ground anchor anchor seat is reinstalled, and the anchor seat is welded and connected with the road reinforcement mesh, and the road surface is poured along the construction advancement direction. While maintaining the integrity of the road surface, the invention provides a certain vertical constraint for the road slab to avoid warping of the road surface.

Description

Structure method for expansion joint of cement concrete pavement

Technical field

What the present invention relates to is a kind of method of technical field of building construction, specifically is a kind of structure method for expansion joint of cement concrete pavement.

Background technology

Cement concrete pavement can produce warpage and dilatation under concrete shrinkage effect, temperature gradient day and night temperature and season effect of factors such as the temperature difference, influence the normal use and the safety of road.For avoiding the generation of this situation, select usually various types of transverse joints to be set along road direction.By the difference of effect, generally can be divided into contract seam and expansion joint (E.J.), wherein expansion joint (E.J.) is true seam, and width is bigger, and spacing is bigger, and expansion joint (E.J.) is used to discharge the dilatancy that the rigid pavement causes owing to variations in temperature.Because it has destroyed the globality on road surface, and at seam crossing the stress concentration phenomenon can take place, road slab is prone to destructions such as seam crossing generation faulting of slab ends and fractures but in actual use.Such as the sunk type cement concrete pavement, because it is built in the underground soil layer, avoided sunlight directly to shine, all more conventional road surface of pavement temperature gradient and day and night temperature is little, so the general rigid pavement of the turgor pressure stress of its actual generation is also little.And the sunk type cement concrete pavement often is in below the groundwater table, and under the effect of vehicular load, it is big that want on the also more conventional road surface of relative settlement that produces between each road slab or inhomogeneous deformation, be prone to cause bad phenomenon such as seam crossing generation faulting of slab ends, purt mud.Along with the upwards expansion extension of seam crossing crack, underground water also can pour into the road surface along the crack, quickens the destruction on road surface, shortens the application life on road surface greatly.On the other hand, existing evidence the destruction of cement concrete pavement mainly be not to cause by the swelling stress extruding.Its failure mechanism is because pavement temperature raises, and warpage takes place under the effect of longitudinal dilatation strain, under the effect of carload, produces fracture again.Therefore, at this moment, conventional expansion joint (E.J.) is set not only not necessarily on the cement concrete pavement, also possibly is harmful to.

Through existing technical literature is retrieved; One Chinese patent application numbers 94245838.9; Put down in writing a kind of " cement concrete pavement seam new construction ", this technology provides a kind of can adapt to various adverse weather conditions, have favorable waterproof property, can stop rainwater water leaking-in cement concrete road bed effectively, prevent the cement concrete pavement seam new construction of cement concrete pavement premature failure.But this technology lays particular emphasis on existing seam construction is transformed, just solved the waterproof problem of pavement joint.Do not provide a kind of method of avoiding being provided with expansion joint (E.J.), just can not solve simultaneously yet the destruction road surface globality that seam causes and the problem of stress concentration of seam crossing are set.

Summary of the invention

The present invention is directed to the above-mentioned deficiency that prior art exists, a kind of structure method for expansion joint of cement concrete pavement is provided, when keeping the road surface globality, for road slab provides certain vertical constraint, avoids the road surface that warpage takes place.

The present invention realizes through following technical scheme, the present invention includes following steps:

Step 1, meteorological survey and geological mapping are carried out in the construction plant, confirm temperature load size and roadbed geological conditions, concrete steps are:

1.1) according to the maximum day and night temperature T in location, road surface _d, road slab maximum temperature gradient T _g, utilize the concrete stiffness equations to calculate swelling stress σ _Te, calculate warping stress σ through the Wei Sitekade formula _Tg

1.2) scene gets some holes point, boring extracting soil carries out laboratory test.Use core cutter method to measure soil body severe γ, use oven drying method to measure subgrade soils moisture content W, calculate the dry unit weight γ of subgrade soil _d, pass through cohesion C and the angle of friction φ that direct shear test of reiteration is measured the soil body again;

1.3) frictional resistance characteristic value q through the single earth anchor of uplift pile test determination _s

Step 2, confirm the construction parameter of earth anchor according to step 1:

2.1) row's shape earth anchor spacing L _a: with swelling stress σ _TeWith warping stress σ _TgReduction is carried out by certain reduction coefficient in the stack back, obtains the total moisture content compression stress ot _t, suppose that it vertically evenly distributes along road.Confirm the spacing L of adjacent rows dress earth anchor again according to its value size _a, can combine on-site actual situations and requirement of engineering suitably to adjust.

2.2) earth anchor length H: according to design anchored force inverse earth anchor length H, H gets two calculating formulas (1) result of calculation H ₁And formula (2) H ₂In big value:

F _a＝q _s×A _s＝πq _sD ₂H ₁(1)

$F_a=W_a+W_s=W_a+{\mathrm{\&gamma;}}_d\&times;\left(\frac{1}{3}\mathrm{\&pi;}{R}^2{H}_2\right)=W_a+\frac{1}{3}\mathrm{\&pi;}{\mathrm{\&gamma;}}_{\mathrm{<figure-callout\; id="2"\; label="d\; H"\; filenames="HDA0000023726280000012.png"\; state="\{\{state\}\}">d</figure-callout>}}{H_{}}^{}{{}_2}^3{\mathrm{<figure-callout\; id="2"\; label="tan"\; filenames="HDA0000023726280000012.png"\; state="\{\{state\}\}">tan</figure-callout>}}^2\mathrm{\&phi;}---\left(2\right)$

In the formula, F _aBe single earth anchor design anchored force; A _sBe the anchoring pile side surface area; W _aBe earth anchor weight (comprising anchor pole weight and slip casting weight); W _sSoil body weight in the earth anchor action cone; R is the earth anchor operating radius.

2.3) rule of thumb reach field condition, confirm the anchoring part length d _mAnd casing diameter D;

2.4) adjacent earth anchor spacing d ₁And d _p: through type (3), (4) are confirmed respectively:

$d_1=\frac{4}{3}H\tan \mathrm{\&phi;}=1.33H\tan \mathrm{\&phi;}---\left(3\right)$

$d_p=\frac{2\sqrt{3}}{3}H\tan \mathrm{\&phi;}=1.15H\tan \mathrm{\&phi;}---\left(4\right)$

2.5) anchoring part is apart from the distance h on top, road surface _t: h _tBe taken as 1/4h～1/3h, h is a road crust thickness.

2.6) the cement paste match ratio: cement: sand=1: 1～1: 2, water intaking gray scale are 0.38～0.45 cement mortar.

Step 3, laid bed course after, carry out earth anchor construction:

3.1) confirm the anchor position according to the result of calculation of step 2, and on the anchor position placement positioning sleeve pipe;

3.2) earth anchor and pore-forming sleeve pipe are vertically put into the pore-forming sleeve pipe, squeeze into the projected depth that earth anchor and pore-forming sleeve pipe to step 2 are confirmed;

3.3) unload anchoring part, connect grouting equipment;

3.4) return and pull out the pore-forming sleeve pipe, and slip casting;

Repeating step 3.2)～3.4), pile driver and grouting equipment displacement by the order of first intermediate and then both sides, are all accomplished until the construction of row's shape earth anchor.

Step 4, confirm that by reinforced concrete structural design specification (GB50010-2002) reinforcement around the earth anchor hangs the terminal horizontal anchorage length c of muscle; Hang muscle lower end horizontal width b; Layout is strengthened hanging the muscle net at row's shape earth anchor place, and the distribution reinforcement that hangs in muscle net and the cement concrete pavement is welded to connect.

Step 5, load onto the earth anchor anchoring part again, anchoring part and road surface steel mesh reinforcement are welded to connect, and build the road surface along the construction direction of propulsion.

Compared with prior art, the present invention has following advantage: 1) for the road surface provides bigger vertical constraint, reduce the road slab effective length, prevent that the road surface is owing to the acting in conjunction of temperature load and carload produces warpage destruction; 2) cancel traditional road surface expansion joint (E.J.), strengthened the globality on road surface, can effectively prevent purt mud, the generation of phenomenons such as faulting of slab ends; 3) improve soft soil roadbed rigidity, reduce roadbed subsidence; 4) simple and reliable, economic and practical, prolonged application life of road greatly, reduce the pavement maintenance input.The present invention is applicable to the highway section that all temps load is less or the road pavement globality is had relatively high expectations that comprises the sunk type road.

Description of drawings

Fig. 1 is a sunk type cement concrete pavement sketch map in the present embodiment;

Among the figure: (a) for passing through floor map, (b) for passing through generalized section.

Fig. 2 is an earth anchor layout sketch map.

Fig. 3 arranges sketch map for earth anchor row vertical section.

Fig. 4 is the earth anchor organigram.

Fig. 5 is the locating sleeve sketch map.

Among the figure: 1 earth anchor, 2 earth anchor places strengthen arrangement of reinforcement, 3 anchor poles, 4 anchor heads, 5 anchoring parts, 6 pore-forming sleeve pipes, 7 anchoring part draw-in grooves, 8 anchoring part screwed holes, 9 locating sleeves.

The specific embodiment

Elaborate in the face of embodiments of the invention down, present embodiment provided detailed embodiment and concrete operating process, but protection scope of the present invention is not limited to following embodiment being to implement under the prerequisite with technical scheme of the present invention.

As shown in Figure 1, be embodiment applied environment: 10m wide a cement concrete road and a speedway generation at grade intersection, to intend and adopt the sinkage type structure form to pass through speedway cement concrete road, road surface thickness is 22cm.Distance is 6m to sunk type road lowest part from the face of land, and for guaranteeing the globality on road surface, the road surface does not allow to be provided with expansion joint (E.J.).

Present embodiment practical implementation step is following:

Step 1, through consulting related data and can confirming following parameter value to the on-the-spot prospecting by boring result that carry out in the place:

1.1) confirm that maximum day and night temperature is T _d=15 ℃, road slab maximum temperature gradient T _g=25 ℃, swelling stress σ _Te=2.1MPa calculates warping stress σ with the Wei Sitekade formula _Tg=2.5MPa;

1.2) soil body that will get from the scene carries out laboratory test with core cutter method and obtain the average severe γ of the soil body=18.5kN/m ³, use oven drying method to measure subgrade soils moisture content W=33%, calculate the dry unit weight γ of the soil body by γ and W _d=14kN/m ³, measure soil body cohesion C=21kPa by direct shear test of reiteration, angle of friction φ=25 °;

1.3) frictional resistance characteristic value q through the single earth anchor of uplift pile test determination _s=150kPa.

Step 2, the parameter value that obtains according to step 1 are confirmed the required parameter of earth anchor construction:

2.1) swelling stress σ _TeWith warping stress σ _TgThe total moisture content compression stress ot that obtains after the reduction is carried out in stack _t=3.7MPa is about 8m thereby calculate the earth anchor spacing;

2.2) earth anchor length H gets H ₁And H ₂In big value, consider certain safety factor after, finally get H=2m;

2.3) according to road surface reinforcement placement situation and anchoring requirement, get the anchoring part length d _m=0.8m, casing diameter D=0.6m;

2.4) adjacent earth anchor spacing d ₁=1.2m, d _p=1.0m,

2.5) anchoring part apart from the top, road surface distance h _t=6cm;

2.6) the cement paste match ratio: cement: sand=1: 1.5, water intaking gray scale are 0.4 cement mortar.

After accomplishing, step 3, roadbed and cushion construction can carry out the earth anchor construction:

3.1) according to the on-the-spot unwrapping wire of the result of calculation of step 2, the position of earth anchor is positioned, the position confirm the back at the anchor point place placement positioning sleeve pipe.

3.2) earth anchor and pore-forming sleeve pipe are vertically put into the pore-forming sleeve pipe, earth anchor and pore-forming sleeve pipe are depressed into the 2m degree of depth;

3.3) anchoring part is backed out, be ready to grouting equipment;

3.4) return and to pull out the pore-forming sleeve pipe, immediately the cement paste for preparing is injected around the anchor pole with certain pressure then, guarantee that expanded diameter is not less than 0.8m;

Repeating step 3.2)～3.4), pile driver and grouting equipment displacement by the order of first intermediate and then both sides, are all accomplished until the construction of row's shape earth anchor.

Step 4, confirm that according to standard the reinforcement around the earth anchor hangs the terminal horizontal anchorage length c=0.6m of muscle, hang muscle lower end horizontal width b=0.9m, arrange at row's shape earth anchor place and strengthen hanging the muscle net that the distribution reinforcement that hangs in muscle net and the cement concrete pavement is welded to connect.

Step 5, to after the pile-forming effect passed examination, load onto the earth anchor anchoring part again, anchoring part and near road surface steel mesh reinforcement are welded, carry out pavement concrete at last and build.

After construction was accomplished, because the expansion joint (E.J.) that causes adverse effect easily is not set, the road surface globality strengthened; The mode of occupation on road surface is greatly improved; The maintenance cycle ratio is provided with the expansion joint (E.J.) road surface and will prolongs more than 50%, and maintenance cost reduces greatly, and the life-span on road surface can improve more than 30%.

Claims (3)

1. a structure method for expansion joint of cement concrete pavement is characterized in that, may further comprise the steps:

Step 1, meteorological survey and geological mapping are carried out in the construction plant, confirm temperature load size and roadbed geological conditions;

Step 2, confirm the construction parameter of earth anchor according to step 1;

Step 3, laid bed course after, carry out earth anchor construction;

Step 4, confirm that by reinforced concrete structural design specification the reinforcement around the earth anchor hangs the terminal horizontal anchorage length c of muscle; Hang muscle lower end horizontal width b; Layout is strengthened hanging the muscle net at row's shape earth anchor place, and the distribution reinforcement that hangs in muscle net and the cement concrete pavement is welded to connect;

Step 5, load onto the earth anchor anchoring part, anchoring part and road surface steel mesh reinforcement are welded to connect, and build the road surface along the construction direction of propulsion.

2. structure method for expansion joint of cement concrete pavement according to claim 1 is characterized in that, described step 1 is specially:

1.1) according to the maximum day and night temperature T in location, road surface _d, road slab maximum temperature gradient T _g, utilize the concrete stiffness equations to calculate swelling stress σ _Te, calculate warping stress σ through the Wei Sitekade formula _Tg

1.2) scene gets some holes point, boring extracting soil carries out laboratory test, uses core cutter method to measure soil body severe γ, uses oven drying method to measure subgrade soils moisture content W, calculates the dry unit weight γ of subgrade soil _d, pass through cohesion C and the angle of friction φ that direct shear test of reiteration is measured the soil body again;

1.3) frictional resistance characteristic value q through the single earth anchor of uplift pile test determination _s

3. structure method for expansion joint of cement concrete pavement according to claim 1 is characterized in that, described step 3 is specially:

3.1) confirm the anchor position according to the result of calculation of step 2, and on the anchor position placement positioning sleeve pipe;

3.2) earth anchor and pore-forming sleeve pipe are vertically put into locating sleeve, squeeze into the projected depth that earth anchor and pore-forming sleeve pipe to step 2 are confirmed;

3.3) unload anchoring part, connect grouting equipment;

3.4) return and pull out the pore-forming sleeve pipe, and slip casting;

Repeating step 3.2)～3.4), pile driver and grouting equipment displacement by the order of first intermediate and then both sides, are all accomplished until the construction of row's shape earth anchor.

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