CN207582473U - Foundation pit supporting construction - Google Patents

Abstract

The utility model provides a kind of foundation pit supporting construction, including：Bored concrete pile, water-stop curtain, rotation cast anchor rope and shaped steel, and the shaped steel is vertically embedded in the water-stop curtain, and top maintains an equal level with ground, and bottom is less than the top of the bored concrete pile, and the top of the bored concrete pile is less than the ground.Foundation pit supporting construction provided by the utility model, shaped steel is embedded in water-stop curtain, it is made to bear the lateral load on ground upper strata, and the height of bored concrete pile is reduced with this, effectively reduces cost.

Description

Foundation pit supporting construction

Technical field

The utility model is related to technical field of building construction, specifically, being a kind of foundation pit supporting construction.

Background technology

Foundation pit belongs to temporary work, and effect is to provide a space, and enable basis builds operation by laying bricks or stones according to design Specified position carries out.With the development of economic construction, the engineering of the big scale of construction such as high-rise building and City complex building Also occur more and more, not only the area of aerial part and height are larger for these big scale of construction engineerings, the area of under ground portion and Depth is also generally all bigger, and these big scale of construction engineering in general can all be located in the bustling location in city, and Floorplanning land used is non- Often nervous, surrounding enviroment also can be more complicated, thus can cause very big influence to the construction of underground engineering, foundation depth is remote Surpass 10 meters, belong to ultra-deep foundation pit, foundation pit is complex, excavates and supporting directly influences engineering construction.To ensure underground knot Structure is constructed and the safety of foundation pit surrounding enviroment, it usually needs to foundation pit side-wall and surrounding enviroment generally use supporting and retaining system, the base of reinforcing Cheat supporting measure.

At present, in foundation pit supporting construction, bored concrete pile play a part of it is main bear lateral load, in general, its top with ground Face height maintains an equal level.

Utility model content

The technical problem to be solved by the present invention is to provide a kind of foundation pit supporting constructions, can reduce the height of bored concrete pile Degree, reduces cost.

In order to solve the above technical problems, the utility model provides a kind of foundation pit supporting construction, including：Bored concrete pile, sealing Curtain revolves cast anchor rope and shaped steel, and the shaped steel is vertically embedded in the water-stop curtain, and top maintains an equal level with ground, bottom Portion is less than the top of the bored concrete pile, and the top of the bored concrete pile is less than the ground.

Further, the shaped steel has multiple, and the bored concrete pile has more, and the shaped steel and the bored concrete pile one are a pair of It should.

Further, the shaped steel is I-steel.

Further, the shaped steel intersects 0.5 ~ 0.7 times of segment length for its overall length with the bored concrete pile.

Further, the shaped steel intersects 0.6 times of segment length for its overall length with the bored concrete pile.

Further, collar tie beam, concrete waist rail and at least one steel wale from top to bottom is further included.

Further, the setting angle for revolving the rope that casts anchor is 25 °.

Foundation pit supporting construction provided by the utility model, shaped steel is embedded in water-stop curtain, it is made to bear ground upper strata Lateral load, the height of bored concrete pile is reduced with this, effectively reduces cost.

Description of the drawings

Fig. 1 is the structural scheme of mechanism of the utility model foundation pit supporting construction；

Fig. 2 is the vertical view of Fig. 1；

Fig. 3 is three axes agitating pile construction punching sequence；

Fig. 4 is three axes agitating pile construction process figure.

In figure, 1. bored concrete piles, 2. water-stop curtains, 3. shaped steel, 4. rotations cast anchor rope, 5. collar tie beams, 6. concrete waist rails, and 7. Steel wale.

Specific embodiment

The utility model is described in further detail in the following with reference to the drawings and specific embodiments, so that those skilled in the art The utility model may be better understood and can be practiced, but illustrated embodiment is not as the restriction to the utility model.

A kind of foundation pit supporting construction, as illustrated in fig. 1 and 2, including：Bored concrete pile 1, revolves cast anchor rope 4 and shaped steel at water-stop curtain 2 3, the shaped steel 3 is vertically embedded in the water-stop curtain 2, and top maintains an equal level with ground, and bottom is less than the bored concrete pile 1 Top, the top of the bored concrete pile 1 is less than the ground.

Shaped steel 3 is embedded in water-stop curtain 2, it is made to bear the lateral load on ground upper strata, bored concrete pile 1 is reduced with this Height, effectively reduce cost.

In one optional embodiment of this implementation, the shaped steel 3 has multiple, and the bored concrete pile 1 has more, the shaped steel 3 It is corresponded with the bored concrete pile 1.Rotation is cast anchor in the gap that rope 4 is set between two shaped steel 3.

In one optional embodiment of this implementation, the shaped steel 3 is I-steel.

In one optional embodiment of this implementation, it is its overall length that the shaped steel 3, which intersects segment length A with the bored concrete pile 1, 0.5 ~ 0.7 times, it is preferred that the shaped steel 3 intersects 0.6 times that segment length is its overall length with the bored concrete pile 1.

In one optional embodiment of this implementation, the water-stop curtain 2 is three axes agitating pile, is used in present embodiment 850@, 600 three axes agitating piles, using " two sprays two are stirred ", set punches construction technology.Sequence carries out as shown in Figure 3 for construction, wherein Dash area is bored to repeat set, to ensure the construction quality of the continuity of wall and connector.

As shown in figure 4, its construction method is：

1. barrier is cleared up

Because the engineering method requires continuous construction, therefore should be carried out clearly to going along with sb. to guard him construction area underground obstacle and pipeline before construction Reason or displacement, to ensure that construction is smoothed out.

2. surveying setting-out

Before construction, first according to design drawing and the coordinate basis point of owner's offer, calculate and go along with sb. to guard him centerline angles point coordinates （Or corner point coordinates）, go out to go along with sb. to guard him center line using the accurate setting-out of measuring instrument, and carry out coordinate data review, while carry out shield Stake carries out engineering survey review list, Party A is submitted to check and accept.

3. excavate groove

According to foundation pit enclosure side control line, groove is excavated, and remove underground obstacle using digging machine, groove dimensions 1200X1200.When underground obstacle is met in place, underground obstacle is abolished totally using pick machine, was generated after such as abolishing Big cavity then needs to be backfilling and compacted, excavates groove again.Soil answers timely processing more than excavation groove, to ensure three axes agitating pile just Often construction, and reach Civilization Worksite requirement.

4. it positions shaped steel to place

Two positioning shaped steel are placed in vertical trench direction, specification is 200 × 200, length 2.5m, then in parallel groove side Be 300 × 300 to two positioning shaped steel specifications are placed, be about 8~12m, corner H profile steel take with building enclosure center line into 45 ° of insertions, H profile steel positioning is using H profile steel positioning card.

5. three axes agitating pile hole position positioning

According to design drawing and control point releasing stake position is measured, stake bit plane deviation is not more than 5cm.This engineering use three Axis blender stake diameter is 850mm, distance of shaft centers 600mm, mixing pile overlap joint 250mm.Three axes agitating pile punches technique using set, Therefore the stake heart is away from for 1200mm.Shaped steel is positioned in groove both sides using 1200mm as spacing, is marked with red paint, ensures to stir Stake is mixed to be accurately positioned every time.

6. machine corrects in place with verticality

Job position is reached, and adjust pile frame verticality and reach more than 0.5% with hoist engine and manpower movement mixing pile machine. The iron ring that Radius is 5cm is welded on stake machine, one plummet of 10m high-altitude suspensions is straightened drilling rod verticality using theodolite, makes lead Hammer is just by iron ring center.Drilling rod must be suitably adjusted before construction every time, plummet is made to be located in iron ring, i.e., drilling rod verticality Control errors are in 0.5%.

Stake machine displacement is assumed unified command of by captain on duty, must examine field condition before mobile, displacement to accomplish it is steady, Safety.After position of p ile machine, it is responsible for checking stake machine stake position by captain on duty, deviation is not greater than 20mm.

It for ease of the control of pile depth, should be marked on drilling rod before construction, mixing pile stake is long cannot be less than for control Designing pile length wipes old label when the long variation of stake, carries out new label.

7. mixing speed and grout injection control

（1）Three axis cement mixing piles are sinking and should all inject cement grout, while stringent sinking control in lifting process With promotion speed.Stir two sprays using two, mixing speed >=30 turn/min, first stirs subsidence velocity≤1m/min, promoted speed≤ 0.4m/min；Second stirs sinking≤1m/min, promotes speed≤0.8m/min.Suitably continue mixing-filling in stake bottom point, do The original record of good each pile；

（2）Prepare cement grout and slurries injection：Arrangement mixes slurry construction platform automatically at the construction field (site), should be into before booting Row slurries stir system, and work of telling somebody what one's real intentions are is carried out to mixing slurry staff before spudding in.The cement mixed weight of cement mixing method takes 15% ~ 25%, the cement mortar ratio of mud is 0.6 ~ 0.8, and the soil cement unconfined compressive strength >=1.0MPa of 28 days, constructed in mud Spray pressure is more than 1.5MPa in journey, and pump discharge requirement is constant.Using 42.5 Portland cements.

8. cleaning, displacement

Proper amount of clear water will be added in aggregate bin, opens slurry pump, mud jacking pipeline and other equipments used is cleaned, then shifts The construction of next pile is carried out again.

Tri-axial deep stirring pile sealing should ensure the continuity of construction as possible, be usually no more than 10 hours, ensure adjacent studs Overlap joint effect, and then ensure its water-stagnating effect.If encountering special circumstances, the construction interval time of adjacent two lag pile is more than 24 Hour, then should handle according to cold seam, the processing method of cold seam be constructed it is cold stitch both sides tri-axial deep stirring pile after, with cold Centered on seam, increase a set of three axis water-seal pile on the outside of foundation pit, to ensure the continuity of entire water-stop curtain.

Meet the treatment measures of the barriers such as boulder：

A, boulder is when barriers buried depth≤3 meter and when more universal（The indivedual barriers encountered in work progress, are applied Working hour removes in time）, the region constructed using common digging machine to needs is removed obstacles, i.e., is in advance dug whole barriers in advance Go out, ensure that construction is continuously smoothed out.

B, boulder is when barriers buried depth≤5 meter and when more universal（The indivedual barriers encountered in work progress, are applied Working hour removes in time）, the region constructed using long-armed digging machine to needs is removed obstacles, i.e., is in advance dug whole barriers in advance Go out, ensure that construction is continuously smoothed out.

C, boulder cannot be dug out barrier using long-armed digging machine as 5 meters of barriers buried depth ＞ and when more universal, The advantages of this part will use dual-pipe high-pressure churning instead instead of tri-axial deep stirring pile, this is not limited by barrier, is carried It is preceding to use geology drill hole, then carry out rotary-spraying construction using two pipe churnings, to ensure water-stagnating effect, use it is in situ constructed with Afterwards, in the row that constructs on the outside of it, and the overlap joint of two edge connectors is carried out.

There is the remedial measure after leakage stake：

If it will be remedied what omitting occurred in three axes agitating pile boundary of works area using single valve high-pressure chemical churning pile.

In one optional embodiment of the present embodiment, designed using four churning anchor cables 4, as shown in Figure 1, from top to bottom Collar tie beam 5, concrete waist rail 6 and two steel wales 7 correspond to one of churning anchor cable 4 respectively.Wherein, anchorage cable design length 15m ~ 22m, Anchor cable uses the beam intensity of 3 beams ~ 4 as 1860MPa high strength low relaxed steel strand wires, and anchor cable incident angle is 25 degree.Anchor cable is not according to Different design values and lock value with section design.Anchor cable tension design value is the KN of 250KN ~ 395, anchor cable lock value（In advance should Power）For the KN of 100 KN ~ 150.Anchor cable is divided into free segment and anchoring section, and freedom length is 5m ~ 9m, anchoring depth for 10m ~ 13m, anchoring body diameter 450mm.

The construction method of churning anchor cable 4：

Before anchoring pile construction, anchoring pile construction fundamental test should be carried out, experiment anchoring pile quantity should not be less than 2 to examine work of constructing The adaptability of skill and construction equipment, and assist determining anchoring pile axial tension design ultimate bearing capacity.

Construct jet mixing soil cement anchoring pile, construction should use drilling, slip casting, stirring, joint bar method.Anchoring pile uses Secondary multiple spray, enlarged footing use four construction technologies sprayed again, and a diameter of Φ 450 of anchoring pile, level inclination is 25 degree, length is 15~22m.By drilling rod hollow hole, inside churning cement grout, the ratio of mud 0.8, general section rotary jet grouting pressure value for 25 ~ 30Mpa；It is 30 ~ 35Mpa to expand head section grouting pressure value；By the hollow channel of above-mentioned drilling rod, the mixing-filling in drilling, into Steel strand wires and anchor head structural member are brought into projected depth after hole, and slip casting is also answered in insertion process.Dowel uses 3 ~ 4 Φ 15.2 prestress wires make, and every steel strand wires tensile strength standard value is 1860Mpa, and every steel strand wires are twisted by 7 steel wires It closes, 0.7m is stayed so as to tensioning outside stake.

Anchoring pile construction is completed, before lower floor's earth excavation, should carry out anchoring pile acceptance test, anchoring pile experiment quantity should be less than 5%.Churning anchor cable construction must be excavated according to staged and layered, and section length is not preferably greater than 35.0m, and lift height is not preferably greater than 2.0m, during lower floor's earth excavation, the piled anchor on upper strata must have the curing time of 15 days or more and complete tensioning fixation.It is slotting Collision steel strand wires are prevented during earth excavation.

Positioning：

After earth excavation groove, absolute altitude should be measured, and bracing wire is marked on fender post.Should be accurate when drilling machine is in place, Pedestal should be leveled up, and the angle of inclination of drilling rod is checked using compass, and drilling hole position horizontal departure should not exceed 20mm, and vertical missing is not 100mm is should be greater than, degree of skewness should not exceed 3%.In place Zhong Wahao gutters and stock tank should be recycled before drilling construction, to avoid It influences to construct due to mud arbitrarily discharges.

Pore-forming：

Soil cement anchoring pile uses special drilling machine pore-forming.It is used if hard soil layer is met in construction and is repeated once drawing bore method, Remaining soil layer uses one-step pore-creating.Steel strand wires are sent to projected depth, carry out slip casting, treat the mud returned out in aperture without sand grains and soil When, it exits drilling rod steel strand wires placement simultaneously and finishes.

Dowel, which makes, to be placed：

Dowel body is made of 3 ~ 4 15.2 steel strand wires materials of Ф, and material therefor need to reach the standard of this kind of strength of materials Value.

Enlarged footing is constructed：

The advance and retreat number of the jet mixing of enlarged footing increases by 2 times than pile body, and to ensure the diameter of enlarged footing, when construction expands Using 30 ~ 35MP pressure operations, enlarged footing is 300~350kg per linear meter(lin.m.) cement consumption on head point.

Stretching construction is the same as common prestress anchorage cable.

Reinforced cement earth anchoring pile construction point；

A, position is determined by construction drawing unwrapping wire, mark before drilling；

B, drilling machine selection should meet requirement of the design of its support to design parameter；

C, the muscle body of reinforced cement earth anchoring pile uses 15.2 steel strand wires of Φ, and dilling angle is 25 degree（Angle with horizontal plane）, The stringent dilling angle for pressing design requirement, stake is long and stake diameter is constructed；

D, dowel body is inserted into general interval time no more than 3h, and should be placed on the center of pile body；

E, dowel should will lock on capping beam and waist rail, be applied per pile anchor lock value in strict accordance with design requirement Add；

F, injecting paste material selects 42.5R grades of Portland cements to starch only, the ratio of mud 0.8；Cement mortar answers uniform mixing, anchor Stake uses secondary multiple spray, and pile body is 200~220kg per linear meter(lin.m.) cement consumption；Enlarged footing is using four multiple sprays, and enlarged footing is per linear meter(lin.m.) Cement consumption is 300~350kg；With mixing with the cement mortar once mixed and stirred should be finished before initial set；

G, general section rotary jet grouting pressure value is 25 ~ 30Mpa, and it is 30 ~ 35Mpa to expand head section grouting pressure value；

The easy problem and its treatment measures in construction：

A, stop to bore in time, after Solve problems in construction, re-start note if there is disconnected slurry phenomenon during construction slip casting Slurry.

B, steel strand wires, which are placed, should be noted that：Steel strand wires are put into before drilling, should check the quality of steel strand wires, it is ensured that steel strand wires group Fill sufficient design requirement.Steel strand wires must not be tapped arbitrarily after placing, and must not hang weight.

C, grouting serous fluid should stir evenly, with stirring with slurries should be finished before initial set, and prevent that stone, sundries are mixed into Slurries.Slip casting operation starts and midway stops the long period, then operation appropriate to the occasion water or thin cement slurry lubrication grouting pump and slip casting Nozzle.When slurries are overflowed in aperture in addition to churning, slip casting can be stopped.

D, arrangement mortar preparation system should make the horizontal pumping distance of mortar be generally no greater than 50 meters, it is ensured that grouting pressure. If pumping distance is more than 50 meters, often increase by 20 meters, grouting pressure accordingly increases 1Mpa.

E, this soil cement anchor pile construction technology profession requirement grade is strong, such as violates construction technology, can cause quality accident, therefore It to require to construct in strict accordance with know-how in work progress.

Anchor cable dynamometry, anchor cable installation dynamometer examine loads change, string formula dynamometer or photoelastic dynamometer etc. can be used.

Dynamometer installation method is as follows：

During anchor dynamometer Embedded installation, the contact surface of dynamometer and each backing plate is smooth, be not allow for crator, welding slag and its He exists foreign matter, reaches all backing plate flat smooths, close with the contact surface of dynamometer.Ensure dynamometer and backing plate and embedded hole Axis it is vertical, gradient and eccentricity value are controlled by related specification and design requirement.Installing rope meter should be influential on its Tensioning loading is carried out before other anchorage cable stretchings of surrounding.When the bearing strength of pressure-bearing base concrete and the anchoring section concrete of anchor cable reaches To after design requirement, interior backing plate, anchor dynamometer, outer backing plate are mounted on to the aperture anchor plate of pressure-bearing base with anchor slab successively On, tensioning is carried out, and frequency meter is connected to monitoring pulling force with sensor.

Tensioning：It pre-tightens after the assay was approved, connects tensioner, before loading tensioning, accurately measure its initial value and environment temperature Degree, it is continuous to survey three times, after the difference of the maxima and minima of reading three times meets design requirement, its average value is taken as monitoring A reference value.Then by technical requirement on design stage loading tensioning, general every grade of load should be estimated once, and afterbody load should Stability monitoring is carried out, three times, the difference of the maximum average value of reading and minimum average B configuration value meets design requirement to continuous measure three times.

Installation locking：Tensile load stabilization locks unloading after meeting design requirement, estimates locking load in time later.Then Stability monitoring after being locked, the interval of monitoring time is determined according to loads change rate, after meeting design requirement, into just Often monitoring.

The protection scope of the utility model is not limited thereto.Those skilled in the art institute on the basis of the utility model The equivalent substitute of work or transformation, are within the protection scope of the utility model.The scope of protection of the utility model will with right It asks subject to book.

Claims (7)

1. a kind of foundation pit supporting construction, which is characterized in that including：Bored concrete pile, water-stop curtain, rotation cast anchor rope and shaped steel, the type Steel is vertically embedded in the water-stop curtain, and top maintains an equal level with ground, and bottom is less than the top of the bored concrete pile, described The top of bored concrete pile is less than the ground.

2. foundation pit supporting construction as described in claim 1, which is characterized in that the shaped steel has multiple, and the bored concrete pile has more Root, the shaped steel are corresponded with the bored concrete pile.

3. foundation pit supporting construction as claimed in claim 2, which is characterized in that the shaped steel is I-steel.

4. the foundation pit supporting construction as described in claims 1 to 3 is any, which is characterized in that the shaped steel and the bored concrete pile phase Hand over 0.5~0.7 times that segment length is its overall length.

5. foundation pit supporting construction as claimed in claim 4, which is characterized in that the shaped steel intersects segment length with the bored concrete pile 0.6 times for its overall length.

6. foundation pit supporting construction as claimed in claim 4, which is characterized in that further include collar tie beam from top to bottom, concrete waist rail with And at least one steel wale.

7. foundation pit supporting construction as claimed in claim 4, which is characterized in that the setting angle for revolving the rope that casts anchor is 25 °.