CN209620035U - Active inclination single-row-pile foundation pit bracing - Google Patents

Abstract

The utility model discloses a kind of active inclination single-row-pile foundation pit bracings, including the single support pile being arranged on the inside of foundation pit edge, the single support pile is tilted to cheating, and a jack is arranged in the stake top of the every single support pile, is provided with crown beam on the single support pile.The utility model carries out active control using jack pair inclination Single row pillars displacement, displacement at pile top can largely be reduced in the identical situation of cutting depth, greatly reduce ground deformation after stake, it avoids damaging ambient enviroment, it can reduce bending simultaneously, make the reduction of pile body design strength, to reduce project cost, has a great economic significance；When stake is long and stake design strength is identical as common campshed, cutting depth can be made to increase, there is preferable technological value；Due to excavation face tilt, foundation pit occur overturning a possibility that greatly reduce, it is very big for the security implications of base pit engineering.

Description

Active inclination single-row-pile foundation pit bracing

Technical field

The utility model relates to a kind of foundation pit supporting construction, especially a kind of active inclination Single row pillars pattern foundation pit supporting structure knot Structure.

Background technique

Row of piles supporting is one of widest pattern foundation pit supporting structure form of current domestic application.Row of piles structure and diaphram wall phase Than having many advantages, such as construction technology is simple, at low cost, horizontal layout is flexible.Spaced pile row retaining structure is suitable for No underground water allows the case where cheating outer precipitation, forms continuous wall side by side when setting water-stop curtain or with other hybrid stakes When, it can also be used to weak aquifer water-bearing stratum.When excavation of foundation pit is shallower, geological conditions is preferable, environmental requirement (especially deformation requirements) When not high, cantilever pile support form can be used.Campshed supporting can also carry out anchoring or in foundation pit plus each using anchor pole The support of seed type improves the support capacity of campshed.It, can be with when excavation of foundation pit area is larger, ground is weak, environmental requirement is high Using Internal-shoring Supporting.When foundation pit soil layer condition is preferable, reaches and draw anchor condition, and when surrounding enviroment are of less demanding, can adopt With drawing anchor formula supporting.

The shortcomings that common campshed supporting, stake are Vertical Pile, carry out campshed supporting using Vertical Pile mainly has:

First, the displacement at pile top of identical cutting depth is big, and internal force is big, so that ground after stake is generated moderate finite deformation, jeopardizes surrounding Environment.

Second, it is easy to cause slope protection pile to fracture when the intensity of stake is inadequate and makes instability of foundation pit, and foundation pit can excavate Depth it is smaller, be easy to that overturning occurs when cutting depth is larger, therefore supporting construction needs bigger section and insertion deep Degree.

During deep pit digging, due to the off-load of deep basal pit cause surrounding soil and foundation pit itself displacement field and There is biggish variation and further leads to ground settlement, building enclosure lateral deformation and the foundation pit bottom in hole week in stress field It is the problems such as uplift of soil, excessive so as to cause displacement at pile top.If applying active control to it, so that it may reduce the soil body and stake top Displacement.

A kind of domestic and international relatively advanced technology is " deep foundation ditch steel support shaft force Hydrauservo System " at present.However, this Kind technology relies primarily on horizontally-supported applied hydraulic axle power to carry out active control to foundation pit deformation, and occupied space is big, makes Valence is high, not environmentally also uneconomical.

Therefore, it researches and develops one kind and is suitable for soft clay area ultra-deep, super foundation, while branch economic, quickly, energy saving, safe Protection structure is the urgent need of existing market development.

Summary of the invention

The utility model is to solve technical problem present in well-known technique and provide a kind of active single pile foundation of inclination Pit supporting construction, the structure can largely reduce displacement at pile top, reduce bending, reduce project cost, increase Cutting depth reduces a possibility that overturning occurs for foundation pit.

The utility model is adopted the technical scheme that solve technical problem present in well-known technique: a kind of active Single-row-pile foundation pit bracing is tilted, including the single support pile being arranged on the inside of the foundation pit edge, the single support pile is to hole It is tilted, one jack is set in the stake top of the every single support pile, is provided with crown beam on the single support pile.

On the basis of above scheme, the utility model has also done following improvement:

The tilt angle of the single support pile is greater than 0 degree and is less than or equal to 30 degree.

The stake bottom depth of the single support pile is 2~2.5 times of excavation of foundation pit depth.

The stake spacing of the single support pile is 2~2.5 times of stake diameters.

The diameter of the single support pile is 300~600mm.

The width of the crown beam is more than or equal to the stake diameter or stake section side length of single support pile, and hat depth of beam is more than or equal to 0.6 times of 0.6 times of single support pile stake diameter or section side length.

Both sides respectively expand 1/2 diameter or 1/2 section side length to the crown beam in the width direction.

The utility model has the advantages and positive effects of:

One) active control is carried out using jack pair inclination Single row pillars displacement, it is permissible in the identical situation of cutting depth Largely reduce displacement at pile top, greatly reduce ground deformation after stake, avoids damaging ambient enviroment, while can To reduce bending, makes the reduction of pile body design strength, to reduce project cost, have a great economic significance.

Two) using jack pair inclination Single row pillars displacement carry out active control, when stake is long and stake design strength and commonly arrange When stake is identical, cutting depth can be made to increase, there is preferable technological value；Since excavation face tilts, foundation pit topples brokenly Bad a possibility that, greatly reduces, very big for the security implications of base pit engineering；

Three) active control is carried out using jack pair inclination Single row pillars displacement, due to tilting the excellent of Single row pillars supporting above Point may need originally using Internal-shoring Supporting or draw the base pit engineering of anchor formula supporting, at this time can merely with cantilever pile supporting To meet design requirement, to keep design and construction easier, and material is saved, to reduce engineering cost.

In conclusion the utility model can be suitable for carrying out pattern foundation pit supporting structure using campshed it is expected to reduce displacement at pile top again, Increase cutting depth, reduce campshed overturning possibility or reduces campshed design strength to reduce the foundation pit support of cost Journey.

Detailed description of the invention

Fig. 1 is the structural schematic diagram of the utility model.

In figure: 1, foundation pit edge；2, crown beam；3, bottom is cheated；4, single support pile；5, jack.

Specific embodiment

For the invention, features and effects that can further appreciate that the utility model, the following examples are hereby given, and cooperates Detailed description are as follows for attached drawing:

Referring to Fig. 1, a kind of active inclination single-row-pile foundation pit bracing, including what is be arranged on the inside of foundation pit edge 1 Single support pile 4, the single support pile 4 is tilted to cheating, very heavy in the stake top setting one of the every single support pile 4 Top 5, is provided with crown beam 2 on the single support pile 4.

The utility model is the improvement to common row of piles supporting, with inclination Single row pillars replace vertical campshed, according to calculating with And site condition, it makes pattern foundation pit supporting structure campshed whole and is tilted a certain angle to foundation pit inside, while jack is set in stake top, to stake Body applies axial control force.

The basic principle of the utility model is:

On the one hand, it is well known that grade of side slope is more stable when small bigger than the gradient, more difficult to topple and monolithic stability Destruction.Similarly there are the side slope of certain slope to stablize than vertical side slope, thus supporting get up it is simpler, to supporting The requirement of structure is lower.The utility model is based on this thought, in the case where place allows, using with constant slope Campshed to foundation pit carry out supporting.Meanwhile when carrying out pattern foundation pit supporting structure with taper pile, the sphenoid after stake with tendency toward sliding is than stake Sphenoid when vertical is small, the reason is that sphenoid is because the gradient has lacked a part after stake.Therefore, the soil body can be big to the active force of stake Width reduces, and such displacement at pile top and pile body stress can all reduce very much.

On the other hand, during deep pit digging, since the variation of displacement and stress fields will lead to surrounding soil Deform, it is excessive so as to cause the soil body and displacement at pile top, if pile body can be given to apply a thrust, thrust direction and the soil body and The direction of displacement of stake top is on the contrary, then can effective limiting displacement.The utility model is based on this thought, is arranged thousand in stake top Jin top applies axial control expansive force by jack pair pile body, so that horizontal thrust component can be generated, using jack pair in The soil body and displacement at pile top carry out effective control in real time, to largely reduce displacement.

For theoretically, the gradient of stake is bigger, and the stress and displacement at pile top of stake are smaller, thus it is more economical, but stake is oblique Degree unconfined cannot increase, because due to the limitation of construction site, the gradient of stake may be kept too big without enough spaces, On the other hand, when the gradient of stake is big, foundation depth stake below is due to reaching foundation pit inner space hereinafter, stake may be will affect The construction of base.In addition the inclination of stake can make the long increase of stake, offset a part because pile strength reduces bring economy, and make Single support pile difficulty of construction increases.Therefore in actual application, the determination of gradient should fully consider respectively for taper pile supporting The factor of aspect.

Under the same conditions, single support pile tilt angle can reduce using the utility model, shortens single support pile Stake it is long, shorten stake spacing, reduce stake diameter.It is needed before construction according to site condition and calculates analysis, determine optimal single branch Fender pile rake angle, it is long to stake to be designed with pile strength.The utility model is only applicable in cantilever pile support pattern.The utility model Recommend the tilt angle of single support pile 4 to be greater than 0 degree and is less than or equal to 30 degree；The stake bottom depth of single support pile 4 is 2~2.5 times Excavation of foundation pit depth；The stake spacing of single support pile is 2~2.5 times of stake diameters；The diameter of single support pile 4 is 300~600mm.

The concrete construction method of the utility model:

One) single support pile 4 uses prefabricated pile, is squeezed into using pile construction method is jumped, and 1~2 pile of interval is pressed into next Prefabricated pile.Cement mixing pile water proof is being set at single supporting stake top 0.2L (L is that the stake of single support pile is long) position The mixing pile stake bottom absolute altitude of curtain, water seal curtain is identical as single support pile stake bottom absolute altitude.

The construction method of above-mentioned cement mixing pile water seal curtain:

1) position: deep mixer arrival refers to fixed pile, centering.

2) it stirs sinking in advance: after the cooling water of deep mixer circulation is normal, starting mixer motor, loosen blender and hang Rope makes blender cut native sinking along leading truck stirring.

3) it prepares cement slurry: when deep mixer sinks to certain depth, that is, starting to stir by the determining match ratio of design Cement slurry is mixed, pours into cement slurry in aggregate bin before mud jacking.

4) it promotes whitewashing stirring: after deep mixer sinks to projected depth, opening slurry pump for cement slurry and be pressed into ground In, and side whitewashing, Bian Xuanzhuan, while deep mixer is promoted in strict accordance with the determining promotion speed of design.

5) upper and lower stirring: cement slurry when deep mixer is promoted to the top surface absolute altitude of projected depth, in aggregate bin is repeated It should just empty.For when weak soil and cement slurry stir evenly, can again by blender while rotation while sink in soil, until design reinforcement is deep Blender is lifted out ground again after degree.

6) it cleans: cleaning cement slurry remaining in whole pipelines, and the weak soil for being adhered to stirring-head is cleaned up.

7) it shifts: deep mixer being moved into next position, is repeated the above steps.

Two) one jack 5 is set in the stake top of every single support pile 4, jack control route is connected to scene and applies Work control centre can control pile body displacement by jack at any time by the detection soil body and displacement at pile top.

Three) crown beam 2 is set on single support pile 4, is connected all single support piles 4 using crown beam 2 integral；Recommend The width of crown beam 2 is more than or equal to the stake diameter (circle stake) or stake section side length (square pile) of single support pile 4, is highly more than or equal to single 0.6 times (circle stake) of support pile stake diameter or 0.6 times (square pile) of stake section side length；Preferable design is: 2 width direction two of crown beam Side respectively expands 1/2 diameter (circle stake) or 1/2 section side length (square pile).The construction of above-mentioned crown beam 2:

1) the crown beam earthwork is excavated using mechanical subregion, is first excavated the first layer earthwork to single support pile and is designed stake top absolute altitude, Starting to abolish pile crown laitance to designed elevation after removing remaining soil, the concrete of stake core top surface wants dabbing to handle, stake top dross is removed, If design requirement is not achieved in designed elevation pile crown concrete strength, must continue to abolish until concrete quality reaches design requirement, insufficient absolute altitude Pouring molding together when section pours crown beam concrete.

2) inter-pile soil is manually flattened to hat bottom elevation, and rams packing reality.

3) reinforcement fabrication can be carried out by crown beam section arrangement of reinforcement after pile crown is abolished.Steel Reinforcing Bar Material, binding error ensure to meet Design and construction code requirement.

4) check simultaneously installation template to crown beam absolute altitude.Must ensure when template support form stable, securely, to prevent pouring Template deformation when concrete, template sectional dimension are made by crown beam section.

5) reinforced bar engineering is completed.Muscle is indulged preferably with HRB335 grades or HRB400 grades of reinforcing bars, stirrup and tension rib should use HPB300 grades and HRB335 grades of reinforcing bars.

6) concreting and maintenance are completed.Strength grade of concrete is not lower than C25, and single support pile main reinforcement anchors into hat Beam is no less than 35d (d is bar diameter).

Four) the enclosed soil body of single support pile to hole 3 designed elevation of bottom is excavated to adopt during excavation or before excavating Apply control expansive force with the single support pile of jack pair, to reduce the soil body and displacement at pile top.It can use and " first control and open afterwards Dig " and " being controlled when excavating " two methods, first method, which first applies pile body, controls pre-expansion power, excavates the soil body afterwards； Second method is each stage in digging process, according to the soil body and displacement at pile top, applies control expansive force, thus to soil Body generates a certain size pre- thrust, can be carried out the excavation of soil layer after stablizing.

For the foundation pit of stage excavation, above-mentioned construction procedure is repeated until being excavated to the bottom of foundation pit.

Although being described above in conjunction with preferred embodiment of the attached drawing to the utility model, the utility model is not It is confined to above-mentioned specific embodiment, the above mentioned embodiment is only schematical, is not restrictive, ability The those of ordinary skill in domain is not departing from the utility model aims and claimed under the enlightenment of the utility model In the case where range, many forms can also be made, these belong within the protection scope of the utility model.

Claims (7)

1. a kind of active inclination single-row-pile foundation pit bracing, which is characterized in that including the list being arranged on the inside of foundation pit edge Support pile is arranged, the single support pile is tilted to cheating, and a jack, In is arranged in the stake top of the every single support pile Crown beam is provided on the single support pile.

2. active inclination single-row-pile foundation pit bracing according to claim 1, which is characterized in that the single supporting The tilt angle of stake is greater than 0 degree and is less than or equal to 30 degree.

3. active inclination single-row-pile foundation pit bracing according to claim 1, which is characterized in that the single supporting The stake bottom depth of stake is 2~2.5 times of excavation of foundation pit depth.

4. active inclination single-row-pile foundation pit bracing according to claim 1, which is characterized in that the single supporting The stake spacing of stake is 2~2.5 times of stake diameters.

5. active inclination single-row-pile foundation pit bracing according to claim 1, which is characterized in that the single supporting The diameter of stake is 300~600mm.

6. active inclination single-row-pile foundation pit bracing according to claim 1, which is characterized in that the width of the crown beam Degree is more than or equal to the stake diameter or stake section side length of single support pile, and hat depth of beam is more than or equal to the 0.6 of single support pile stake diameter Times or 0.6 times of stake section side length.

7. active inclination single-row-pile foundation pit bracing according to claim 6, which is characterized in that the crown beam is along wide Degree direction both sides respectively expand 1/2 diameter or 1/2 section side length.