CN107587511B - For preventing and administering the long-short pile ruggedized construction and reinforcement means of foundation pit bottom heave - Google Patents
For preventing and administering the long-short pile ruggedized construction and reinforcement means of foundation pit bottom heave Download PDFInfo
- Publication number
- CN107587511B CN107587511B CN201710962053.5A CN201710962053A CN107587511B CN 107587511 B CN107587511 B CN 107587511B CN 201710962053 A CN201710962053 A CN 201710962053A CN 107587511 B CN107587511 B CN 107587511B
- Authority
- CN
- China
- Prior art keywords
- long
- foundation pit
- short
- piling bar
- depth
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Piles And Underground Anchors (AREA)
Abstract
The present invention provides a kind of for preventing and administering the long-short pile ruggedized construction and reinforcement means of foundation pit bottom heave.The method is suitable for the foundation pit that depth is no more than 5m, and there are weak substratums for bottom of foundation ditch.The method carries out the reinforcing of basement weak subjacent bed using short stakes and the spaced apart mode of long piling bar, and short stakes reinforce first layer weak substratum, and long piling bar reinforces remaining one or more layers weak substratum；The short stakes, long piling bar are fully inserted into Foundation Pit bottom, and lower end passes through and is embedded in the good soil layer of closest weak substratum to be reinforced after reinforcing weak substratum, and the foundation bearing capacity of good soil layer embedded by short stakes and long piling bar bottom end is greater than 80kPa.The present invention can either improve basal heave stability, the prevention and treatment problem of effective solution foundation pit bottom heave, and not need large area earth excavation, the influence by adverse weather is avoided, and easy for construction efficient, the construction period is shorter, project cost is low, is worthy of popularization.
Description
Technical field
The present invention relates to Soft Deep Foundation Pits, slope reinforcement field, and in particular to one kind is for preventing and administering Foundation Pit
The long-short pile of bottom protuberance reinforces framework and reinforcement means.
Technical background
Due to geologic origin, such as the deposition in history lake, river；Or the selection due to construction project base position, make
Substrate location may be fallen on the crust layer with weak substratum；Or when soft clay area carries out excavation of foundation pit, it is easy hair
Raw building enclosure sidesway and foundation pit bottom heave, so having to consider foundation pit stable problem, wherein pit accident stabilization is tested
Very the key link at last.
In processing soft soil foundation excavation, substrate there are when weak substratum, salvage of foundation pits, Steel-bar Pile, coagulation can be often used
The methods of native stake, sand pile, lime pile, chemical grouting or piling prepressing, wherein the most commonly used with deal pile and fir pile.Pine sheet
Body rosin rich in, these rosin can prevent well underground water and bacterium from corroding to it, be suitable for level of ground water with
Lower work is particularly suitable for the processing of south muck soil soft foundation, and slope displacement is controlled in deep foundation pit support and has been risen very greatly
Effect, compensates for the rough sledding that soil nail wall works in soft mud.Deal pile has good anti-bending strength in the soil body,
Deal pile, which is squeezed into, according to certain length and reasonable spacing in the middle part of excavation slope forms one of earth-retaining barrier, it can be effectively
Reduce soil body lateral pressure, to achieve the purpose that keep stability of slope.
In fact, for the foundation pit of depth 3m~5m, widely applying deal pile+soil in the engineering practice of pattern foundation pit supporting structure
It follows closely (anchor pole) and is used as fender body.The timber that two kinds of specifications would generally be used, one is 4m~6m long, diameter 150mm~200mm
Short stakes, 20 yuan of every radical valence lattice are relatively common；Another kind is the timber of 9m long, more rare.Timber played in fender body with
Lower effect (1) earth-retaining effect；(2) horizontal pressure force is born；(3) prevent foundation pit from integrally destroying；(4) reduce crater wall displacement；(5) it prevents
Bottom heave.After timber is arranged, on the one hand the self weight of the crater wall soil body can be transmitted downwards by timber, while timber also blocks
The channel of soil body movement, plays good resistant function to bottom heave, while also reducing ground settlement, increases crater wall
Stabilization.However the case where multilayer weak substratum is existed below for foundation pit bottom surface, piling bar, mixing pile, perfusion are used merely
Stake is reinforced, and there is the problem that construction is inconvenient, speed is slow, cost is higher.
Length pile supporting system is a kind of safe and reliable support system.Micro- weathered rock formation buried depth is shallower, big rise and fall
Stratum have and save the duration, reduce the advantages such as difficulty of construction, be widely applied in the foundation pits such as subway, building, industry, and
It is developed for handling some special broken piles, achieves good economic benefit.In long-short pile foundation pit supporting system, cantilever
The mechanism that Length discrepancy foundation pit supporting pile cooperates are as follows: mainly build-in and antidumping by long stake finally carries soil pressure；
Stub only plays the role of earth-retaining and transmitting soil pressure.In general, the maximum of stub is curved in long-short pile foundation pit supporting system
Length stake in the isometric pile supporting system of moment ratio tradition is small, and the long stake in the maximal bending moment pile supporting system more isometric than tradition for growing stake
It is big by about one time.The overall stability of foundation pit is by growing stake control, and stub meets bending resistance requirement, therefore the construction method of long-short pile is filled
The shearing resistance effect of the soil body has been waved in distribution, and the soft soil foundation pit of less demanding to Deformation control has good practicability.It is overall and
Speech, length pile supporting system has no significant difference compared with the isometric pile supporting system of tradition on support capacity, but long-short pile
Support system can generally reduce project amount, and can obtain significant economic benefit.
Summary of the invention
The present invention is insufficient according to prior art to be provided a kind of long-short pile for preventing and administering foundation pit bottom heave and adds
Gu framework and reinforcement means, when this method has two layers or two layers or more for foundation pit bottom surface weak substratum below, in slope foot
The long-short pile that interval is laid is squeezed into, first layer weak substratum (i.e. shallow-layer weak substratum) is reinforced with short stakes, with long piling bar
The second layer and second layer weak substratum below (i.e. deep layer weak substratum) are reinforced, improves foundation pit Resistant heave to reach
The purpose of stability, the present invention utilize the collective effect of long-short pile, can either improve basal heave stability, make up to rule
Model requirement, and large area earth excavation is not needed, the influence by adverse weather is avoided, can be accelerated construction progress, work is reduced
Journey investment.
A kind of technical solution provided by the invention: long-short pile reinforcing knot for preventing and administering foundation pit bottom heave
Structure, including foundation pit just have two layers or two layers or more of weak substratum, it is characterised in that: the reinforcing under the hole of foundation pit
Structure further includes along the more short stakes and long piling bar at the slope foot interval insertion Foundation Pit bottom of foundation pit slope slope surface, the short wood
Stake is fully inserted into Foundation Pit bottom, and first layer weak substratum square under lower end perforation Foundation Pit, and is embedded in first layer weakness
Below subjacent bed in the viscous soil horizon of closest first layer weak substratum, the long piling bar passes through and is fully inserted into Foundation Pit bottom,
Its lower end passes through all weak substratums, and is embedded in closest bottom weak substratum below bottom weak substratum
In viscous soil horizon；The foundation bearing capacity of viscous soil horizon embedded by the short stakes and long piling bar bottom end is greater than 80kPa.
The present invention preferably technical solution: the short stakes are the deal pile of length 4m~6m, diameter 150mm~200mm
Or fir pile, complete appearance is lossless, and the smooth zero defect of pile body, upper and lower even thickness after peeling, the insertion end of short stakes are in
It is cone-shaped；The long piling bar is I-steel or channel steel, and insertion end is wedge shape.
The present invention preferably technical solution: the depth of the foundation pit is no more than 5m, short stakes and long piling bar lower end insertion ground
Depth in viscous soil horizon of the base bearing capacity greater than 80kPa is greater than 1m.
The present invention preferably technical solution: the short stakes and long piling bar are equidistantly uniformly distributed, and adjacent short stakes and
Spacing between long piling bar is 0.5-1m.
It is provided by the invention a kind of for preventing and administering the long-short pile reinforcement means of foundation pit bottom heave, it is characterised in that
Steps are as follows for Specific construction:
(1) according to geological survey and surveying determine the size of foundation pit, depth, Foundation Pit bottom weak substratum position,
The depth of the number of plies and every layer of weak substratum, when foundation depth is no more than 5m, there are two layers or two layers or more of weaknesses at hole bottom
When subjacent bed, start to carry out long-short pile consolidation process；
(2) the resistance to chloride ion check formula according to specified in " JGJ120-2012 building foundation pit supporting technical regulation "
It calculates when meeting basal heave stability requirement, short stakes and long piling bar are respectively embedded into the depth D1 and D2 at hole bottom most
Then small value obtains first layer weak substratum according to the data surveyed in step (1), first layer weak substratum lower section is most faced
Below viscous soil horizon of the close and foundation bearing capacity greater than 80kPa, bottom weak substratum and bottom weak substratum most
It closes on and foundation bearing capacity is greater than the viscous soil horizon depth value of 80kPa, and calculated short stakes and long piling bar is combined to distinguish
The value range of insertion hole bottom depth determines that the stake of short stakes and long piling bar is long, and wherein the length of short stakes is greater than short stakes insertion hole
The minimum value of bottom depth D1, and be greater than or equal to below Foundation Pit bottom surface to first layer weak substratum closest to foundation bearing
The depth of the position 1m in viscous soil horizon of the power greater than 80kPa；The length of long piling bar is greater than long piling bar insertion hole bottom depth D2 most
Small value, and be greater than or equal to below Foundation Pit bottom surface to bottom weak substratum closest to foundation bearing capacity be greater than 80kPa
Viscous soil horizon in the position 1m depth；Then begin preparing short stakes and long timber, the short stakes using length 4m~6m,
The deal pile or fir pile of diameter 150mm~200mm, complete appearance is lossless, and the smooth zero defect of pile body after removing the peel, thick up and down
It is thin uniformly, and be inserted into be whittled into it is cone-shaped；The long piling bar uses I-steel or channel steel, and insertion end is cut into using oxy-acetylene
Wedge shape；
(3) it layouts the insertion positions of determining short stakes and long piling bar along the scribing line of foundation pit slope foot edge, then starts to construct
Short stakes, when every short stakes are constructed, tip cone end downward, using hydraulic crawler excavator be completely forced into soil layer, really
Its lower end of every short stakes is protected across Foundation Pit bottom underlying first layer weak substratum, and is inserted into below first layer weak substratum
Closest to viscous soil horizon of the foundation bearing capacity greater than 80kPa in the position below 1m, every 3~5min is pressed into a short wood
Stake；
(4) after short stakes are all pressed into, start the construction for carrying out long piling bar, long piling bar is hung to by stake by crane first
Position, and after centering, straightening, it is squeezed into using hammer driven, vibration, static(al) is pressed into or shakes any one mode in hammer driven
It is completely forced into soil layer, it is ensured that every root long piling bar lower end passes through square bottom weak substratum under Foundation Pit, and is inserted into
Below bottom weak substratum closest to soil layer of the foundation bearing capacity greater than 80kPa in the position below 1m, every pile
Construction time be 2~5min；The long piling bar that construction is completed is spaced apart from each other with short stakes, and between adjacent long piling bar and short stakes
Spacing be 0.5-1m.
When carrying out Stability Checking to long-short pile in step (2) of the present invention, using " JGJ120-2012 building foundation pit supporting
Technical regulation " specified in resistance to chloride ion check formula it is as follows:
q1=0.5 γ1H0+γ2D ④
q2=γ1H0+γ2D+q ⑤
In formula: Ks--- Resistant heave safety coefficient；Security level is second level, the supporting construction of three-level, is no less than respectively
1.6,1.4；
H0--- foundation depth (m)；
D --- supporting construction building-in depth (m) when having weak substratum below soil blocking component bottom surface, takes foundation pit bottom surface
To the soil thickness of weak substratum top surface；
γ1--- more than the outer soil blocking component bottom surface of foundation pit native average severe (kN/m3)；
γ2--- average severe (kN/m more than soil blocking component bottom surface native in foundation pit3)；
C --- native cohesive strength (kPa) below soil blocking component bottom surface；
φ --- native internal friction angle (°) below soil blocking component bottom surface；
Nc、Nq--- coefficient of bearing caoacity；
Q --- ground evenly load (kPa)；
d1--- soil nail wall slope surface width (m)；
d2--- the calculating width (m) of ground evenly load can use d2=H0。
When every short stakes in step (3) of the present invention are constructed: using manually stake is helped in place, by the bucket of hydraulic crawler excavator
It turns around and withholds short stakes, short stakes are first pressed into ground certain depth from steady, then allows and a people is helped to leave, it will be short by excavator
Timber is pressed onto projected depth.
When every root long piling bar construction in step (4) of the present invention: long piling bar is sling using 3t crane, human assistance centering,
Straightening is first allowed and a people is helped to leave, then long piling bar is pressed onto design using pile press machine using pile press machine indentation certain depth from after surely
Depth.
Deal pile used in the present invention, the deal pile market price of general long 4m are 20 yuan/root, and specification is A48 δ 3.3
100 yuan/the root of floral tube price of long 4m, the I of 9m long22aAbout 1300 yuan/root of type I-steel, wherein A represents diameter, and δ represents floral tube wall
The cost ratio of thickness, three kinds of stakes is about timber: floral tube: I-steel=1:5:10, therefore apparent using the economy of timber.
The present invention is easy for construction, and the raw material such as timber used, I-steel are easily obtained, construction using excavator indentation side
Method, it is easy for construction, it will not be to the raw excessive interference of substrate local products.Scheme of the present invention combines the excellent of timber and steel H pile
Gesture carries out timber and piling bar arranged for interval, not only can effectively solve the prevention and treatment problem of foundation pit bottom heave, but also the side of can reduce
Case cost, while also convenience and high-efficiency of constructing.
Detailed description of the invention
Fig. 1 is the ruggedized construction schematic diagram of the embodiment of the present invention；
Fig. 2 is the ruggedized construction diagrammatic cross-section of the embodiment of the present invention；
Fig. 3 is the ruggedized construction top view of the embodiment of the present invention；
Fig. 4 is the bottom heave sliding surface schematic diagram of the embodiment of the present invention；
Fig. 5 is the bottom heave Stability Checking schematic diagram in the present invention；
Fig. 6 is length pile constructing process figure of the invention.
In figure, 1-foundation pit slope top of the slope, 2-foundation pit slope slope surfaces, 3-short stakes, 4-long steel H piles, 5-foundation pits
Cheat bottom, 6-first layer weak substratums, 7-bottom weak substratums, 8-top of the slope loads, under 9-hole bottom first layers are weak
The Character On The Multiple Slide Plane of sleeping layer top surface and circular sliding surface composition, 10-cross the circular sliding surface at stub bottom, the 11-hole bottom second layers
The Character On The Multiple Slide Plane of weak substratum top surface and circular sliding surface composition, the circular sliding surface at 12-too long stake bottoms, 13-foundation pits
Slope surface width, the calculating width of 14-ground evenly loads, 15-foundation depths, 16-foundation pit bottom surfaces to Resistant heave Calculation Plane
Between the thickness of the layer, 17-foundation pit bottom surfaces to the natural density of soil layer between Resistant heave Calculation Plane and respective thickness multiply
Machine, native distributed load in the above slope surface width range of 18-Resistant heave Calculation Planes, 19-Resistant heave Calculation Planes are with Shangdi
Face evenly load calculates the distributed load of figure in width range.
Specific embodiment
The present invention will be further described with reference to the accompanying drawings and examples.One kind as shown in Figure 1 to Figure 3 is for preventing
With the long-short pile ruggedized construction for administering foundation pit bottom heave, including foundation pit, just have under the hole of foundation pit two layers or two layers or more
Weak substratum, it is characterised in that: the ruggedized construction further include along foundation pit slope slope surface 2 slope foot interval be inserted into foundation pit
The more short stakes 3 and long piling bar 4 at bottom 5 are cheated, the depth of the foundation pit 2 is no more than 5m., the short stakes 3 be length 4m~6m,
The deal pile or fir pile of diameter 150mm~200mm, complete appearance is lossless, and the smooth zero defect of pile body after removing the peel, thick up and down
Thin uniform, the insertion end of short stakes 3 is in cone-shaped；The long piling bar 4 generally uses the I-steel or channel steel of length 6m~10m,
Its insertion end is wedge shape.The short stakes 3 are fully inserted into Foundation Pit bottom 5, and the first layer of 5 lower section of lower end perforation Foundation Pit bottom is soft
Weak subjacent bed 6, and be embedded in the viscous soil horizon of the 6 closest first layer weak substratum 6 in lower section of first layer weak substratum, it is described
Long piling bar 4, which passes through, is fully inserted into Foundation Pit bottom 5, and lower end passes through all weak substratums, and is embedded under bottom weakness and crouches
In the viscous soil horizon of the 7 closest bottom weak substratum 7 in lower section of layer；It is glued embedded by 4 bottom end of the short stakes 3 and long piling bar
Property soil layer foundation bearing capacity be greater than 80kPa.And short stakes 3 and 4 lower end of long piling bar insertion foundation bearing capacity are viscous greater than 80kPa
Property soil layer in depth be greater than 1m.The short stakes 3 and long piling bar 4 are equidistantly uniformly distributed, and adjacent short stakes 3 and long piling bar
Spacing between 4 is 0.5-1m.
Embodiment: the present invention is embodied for the reinforcing of a certain Deep Foundation Pit, and project profile: place is located at elder brother
Bright city Guandu District, projects awaiting construction plan total 52020.60 ㎡ of land area, foundation pit vertical cut line Zhou Changyue 849m, are equipped with one layer
Basement section and two layers of basement section, 3.6~7.7m of excavation of foundation pit depth.The supporting scheme of use are as follows: (1) slope+length
Auger boring pouring pile+recoverable prestressed anchor cable scheme；(2) slope+grouting tube scheme.
Foundation pit west side uses supporting scheme (2), and according to geology prospecting report, the depth of foundation pit is 3.5m, deposits below bottom
In two weak substratums, length is about 200m, and the depth of first layer weak substratum is 4.5m, second layer weak substratum
Depth is 9m；If not using reinforcement measure to prevent and treat bottom heave, the sliding surface of resistance to chloride ion checking computations is to include weakness
The Character On The Multiple Slide Plane of subjacent bed top surface and circular sliding surface, respectively Fig. 4 bottom heave sliding surface illustrate graph laplacian 9 and label
11, then can the resistance to chloride ion calculation formula according to specified in " JGJ120-2012 building foundation pit supporting technical regulation "
Obtain hole bottom first layer, second layer weak substratum stability against heave property coefficient, respectively K1=1.53 and K2=1.46, and be somebody's turn to do
The deep pit monitor grade of construction work is second level, takes Ks=1.6, then there is K1<KsAnd K2<Ks, it is unsatisfactory for the stability against heave of specification
Property require, it is therefore desirable to reinforced.
The specific method is as follows for its reinforcing:
(1) the resistance to chloride ion check formula according to specified in " JGJ120-2012 building foundation pit supporting technical regulation "
And the numerical value of exploration is determined and is laid out pile using the timber interval 1m of diameter 150mm, length 4m, is carried out first layer weak substratum and is added
Gu；Using the I of length 9m22aSteel H pile interval 1m lays out pile, and carries out the reinforcing of second layer weak substratum；
(2) it layouts the insertion positions of determining short stakes and long piling bar along the scribing line of foundation pit slope foot edge, then starts to construct
Whether intact short stakes need to check timber appearance before the construction of every short stakes, and check after peeling whether is pile body
Smooth zero defect, upper and lower even thickness, to guarantee the quality of timber, then the insertion end of deal pile 3 is whittled into it is cone-shaped, so as to
In in piling, smoothly pile body is finally all pressed into soil energy by injection ground, reduction resistance, protection pile crown；When Specific construction,
Using manually stake is helped in place, tip cone end downward, the bucket of hydraulic crawler excavator is turned around and withholds short stakes, first by short stakes pressure
Enter ground certain depth from steady, then allow and a people is helped to leave, short stakes are pressed by excavator and are completely forced into soil layer, it is ensured that is every
Its lower end of root short stakes passes through Foundation Pit bottom underlying first layer weak substratum, and is inserted into below first layer weak substratum and most faces
The position below 1m in viscous soil horizon of the close foundation bearing capacity greater than 80kPa, every 3~5min are pressed into a short stakes；
(3) after short stakes are all pressed into, start the construction for carrying out long piling bar, institute deep in view of weak soil soil property in place
To use static press piling here；Pile crown with oxy-acetylene is cut into wedge shape by piling bar insertion end before constructing, then measure, unwrapping wire it is fixed
Steel H pile is sling with 3t crane in stake position, and worker assists centering, straightening, is pressed into piling bar with crawler type pile press machine, certain depth is certainly
After steady, allow and a people is helped to leave, steel H pile pressure is completely forced into soil layer by crawler type pile press machine, it is ensured that every root long piling bar lower end
The square bottom weak substratum under Foundation Pit, and be inserted into below bottom weak substratum closest to foundation bearing capacity
Greater than the position below 1m in the soil layer of 80kPa, the construction time of every pile is 2~5min；Construct complete long piling bar with
Short stakes are spaced apart from each other, and the spacing between adjacent long piling bar and short stakes is 1m.
After excavation slope bottom is pressed into long-short pile, basal heave stability checking computations, resistance to chloride ion are carried out again
The sliding surface of checking computations is the circular sliding surface by stake bottom, respectively the 10 and 12 of Fig. 4 bottom heave sliding surface schematic diagram, checking computations
Process is as follows:
1, it is directed to first layer weak substratum, is laid out pile using the timber interval 1m of diameter 150mm, length 4m, carries out first
Layer weak substratum is reinforced.Timber pile top is embedded in the cohesive soil that foundation bearing capacity below first layer weak substratum is greater than 80kPa
1.2m in layer, thus may determine that following parameter: foundation depth H0=3.5m, hole bottom is away from soil blocking component bottom distance D=4m, viscosity
Soil layer cohesive strength c=34kPa, internal friction angleTop of the slope distributed load is set to q=20kPa.
Coefficient of bearing caoacity:
The soil body is averaged severe on the outside of foundation pit:
The soil body is averaged severe on the inside of foundation pit:
Soil body load within the scope of soil nail wall:
Soil body load in the evenly load computer capacity of ground:
q1=15.82 × 3.5+14.45 × 4+20=133.17kPa
Substituting into formula has basal heave stability coefficient:
Because of K1'=3.94 > Ks=1.6, so, the resistance to chloride ion of first layer weak substratum is met the requirements.
2, it is directed to second layer weak substratum, using the I of length 9m22aSteel H pile interval 1m lays out pile, and it is soft to carry out the second layer
Weak subjacent bed is reinforced.Foundation bearing capacity is greater than below steel H pile pile top insertion timber pile top insertion second layer weak substratum
The viscous soil horizon 1.4m of 80kPa, thus may determine that following parameter: foundation depth H0=3.5m, hole bottom away from soil blocking component bottom away from
From D=9m, viscous soil horizon cohesive strength c=28.6kPa, internal friction angleTop of the slope distributed load is set to q=20kPa.
Coefficient of bearing caoacity:
The soil body is averaged severe on the outside of foundation pit:
The soil body is averaged severe on the inside of foundation pit:
Soil body load within the scope of soil nail wall:
Soil body load in the evenly load computer capacity of ground:
q1=15.552 × 3.5+14.84 × 9+20=207.992kPa
Substituting into formula has basal heave stability coefficient:
Because of K'2=5.86 > Ks=1.6, so, the resistance to chloride ion of second layer weak substratum is met the requirements.
Grouting tube, steel H pile, long screw auger is respectively adopted also directed in the anti-protuberance reinforcing scope of 200m in inventor
Hole pouring pile, length piling method of the present invention reinforce pair cost calculate.Wherein grouting tube is designed as 3.3@500 of A48 δ,
Every meter of cement consumption 50kg, then slip casting be floral tube price 230+243=468 member/root, totally 400,18.92 ten thousand yuan of total price；I-shaped
Piling bar is designed as I22a@1000, every 1300 yuan, totally 200,26.00 ten thousand yuan of total price；Long screw auger drilling deposited pile is designed as
A600@1200, every 3500 yuan, totally 167,58.45 ten thousand yuan of total price；The mentioned long-short pile design of the present invention are as follows: timber A100
2400, every 20 yuan, common root 84,0.168 ten thousand yuan of timber total price, piling bar is designed as I22a@2400, every 1300 yuan, common root 84,
10.92 ten thousand yuan of steel H pile total price, 11.088 ten thousand yuan of scheme total price.So the cost ratio of four kinds of schemes are as follows: long-short pile of the present invention
Scheme: grouting tube scheme: steel H pile scheme: long screw auger drilling deposited pile scheme=11.088 ten thousand yuan: 18.92 ten thousand yuan:
26.00 ten thousand yuan: 58.45 ten thousand yuan, the economic advantages of the mentioned long-short pile Scheme of Strengthening of the present invention clearly, and are saved the duration, are applied
Work is convenient.
It can see by analysis above, Foundation Pit bottom will lead to there are when weak substratum without slope reinforcement
Cheating bottom, there are biggish protuberance risks.The floral tube generally used is reinforced, concrete-pile is reinforced, simple piling bar is reinforced, and all has one
Fixed problem, such as the problems such as inconvenient, speed is slow, cost is higher of constructing.And the mentioned reinforcement means of the present invention, timber used,
The raw material such as I-steel are easily obtained, method of the construction using excavator indentation, high construction efficiency, will not be raw to substrate local products excessive
Interference.The collective effect that the method for the invention is filled using short stakes and long steel, can either improve basal heave stability, have
The prevention and treatment for solving the problems, such as foundation pit bottom heave of effect, reaches code requirement, and do not need large area earth excavation, avoids incident
It is influenced, can be accelerated construction progress by adverse weather, and the present invention suggests plans with obviously economic sexual clorminance, is worth
It promotes and applies.
Claims (4)
1. a kind of for preventing and administering the long-short pile reinforcement means of foundation pit bottom heave, it is characterised in that Specific construction step is such as
Under:
(1) size, the depth, Foundation Pit bottom weak substratum position, the number of plies of foundation pit are determined according to geological survey and exploration
And the depth of every layer of weak substratum, when foundation depth is no more than 5m, hole bottom is opened there are when two layers or more of weak substratum
Begin to carry out long-short pile consolidation process；
(2) the resistance to chloride ion check formula according to specified in " JGJ120-2012 building foundation pit supporting technical regulation " calculates
Out when meeting basal heave stability requirement, short stakes and long piling bar are respectively embedded into the minimum for cheating the depth D1 and D2 at bottom
Value, then according to the data surveyed in step (1) obtain first layer weak substratum, below first layer weak substratum closest to
And most face below viscous soil horizon of the foundation bearing capacity greater than 80kPa, bottom weak substratum and bottom weak substratum
Close and foundation bearing capacity is greater than the viscous soil horizon depth value of 80kPa, and combines calculated short stakes and long piling bar difference embedding
The value range for entering to cheat bottom depth determines that the stake of short stakes and long piling bar is long, and wherein the length of short stakes is greater than short stakes insertion hole bottom
The minimum value of depth D1, and be greater than or equal to below Foundation Pit bottom surface to first layer weak substratum closest to foundation bearing capacity
The depth of the position 1m in viscous soil horizon greater than 80kPa；The length of long piling bar is greater than the minimum of long piling bar insertion hole bottom depth D2
Value, and be greater than or equal to below Foundation Pit bottom surface to bottom weak substratum closest to foundation bearing capacity greater than 80kPa's
The depth of the position 1m in viscous soil horizon；Then short stakes and long piling bar are begun preparing, the short stakes are using length 4m~6m, straight
The deal pile or fir pile of diameter 150mm~200mm, complete appearance is lossless, and the smooth zero defect of pile body, upper and lower thickness after peeling
Uniformly, and be inserted into end be whittled into it is cone-shaped；The long piling bar uses I-steel or channel steel, and insertion end is cut into using oxy-acetylene
Wedge shape；
(3) it layouts the insertion positions of determining short stakes and long piling bar along the scribing line of foundation pit slope foot edge, then starts short wood of constructing
Stake, when every short stakes are constructed, tip cone end downward, is completely forced into soil layer using hydraulic crawler excavator, it is ensured that every short
Its lower end of timber passes through Foundation Pit bottom underlying first layer weak substratum, and be inserted into below first layer weak substratum closest to
The position below 1m in viscous soil horizon of the foundation bearing capacity greater than 80kPa, every 3~5min are pressed into a short stakes；
(4) after short stakes are all pressed into, start the construction for carrying out long piling bar, long piling bar be hung to by stake position by crane first,
And after centering, straightening, squeezed into using hammer driven, vibration, any one mode in static(al) indentation or vibration hammer driven is incited somebody to action
It is completely forced into soil layer, it is ensured that every root long piling bar lower end passes through square bottom weak substratum under Foundation Pit, and is inserted into most
Below bottom weak substratum closest to viscous soil horizon of the foundation bearing capacity greater than 80kPa in the position below 1m, every
The construction time of stake is 2~5min；The long piling bar that construction is completed is spaced apart from each other with short stakes, and adjacent long piling bar and short stakes it
Between spacing be 0.5-1m.
2. it is according to claim 1 a kind of for preventing and administering the long-short pile reinforcement means of foundation pit bottom heave, it is special
Sign is the resistance to chloride ion check formula described in step (2) are as follows:
q1=0.5 γ1H0+γ2D ④
q2=γ1H0+γ2D+q ⑤
In formula: Ks--- Resistant heave safety coefficient；Security level is second level, the supporting construction of three-level, respectively no less than 1.6,
1.4；
H0--- foundation depth (m)；
D --- supporting construction building-in depth (m), when having weak substratum below soil blocking component bottom surface,
Take foundation pit bottom surface to the soil thickness of weak substratum top surface；
γ1--- more than the outer soil blocking component bottom surface of foundation pit native average severe (kN/m3)；
γ2--- average severe (kN/m more than soil blocking component bottom surface native in foundation pit3)；
C --- native cohesive strength (kPa) below soil blocking component bottom surface；
φ --- native internal friction angle (°) below soil blocking component bottom surface；
Nc、Nq--- coefficient of bearing caoacity；
Q --- ground evenly load (kPa)；
d1--- soil nail wall slope surface width (m)；
d2--- the calculating width (m) of ground evenly load takes d2=H0。
3. it is according to claim 1 a kind of for preventing and administering the long-short pile reinforcement means of foundation pit bottom heave, it is special
When levying the every short stakes construction being in the step (3): it uses and manually helps stake in place,
The bucket of hydraulic crawler excavator is turned around and withholds short stakes, short stakes are first pressed into ground certain depth from steady, are then allowed
It helps a people to leave, short stakes is pressed onto projected depth by excavator.
4. it is according to claim 1 a kind of for preventing and administering the long-short pile reinforcement means of foundation pit bottom heave, it is special
When levying the every root long piling bar construction being in the step (4): long piling bar is sling using 3t crane, human assistance centering, straightening,
It first allows and a people is helped to leave from after surely using pile press machine indentation certain depth, then long piling bar is pressed by projected depth using pile press machine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710962053.5A CN107587511B (en) | 2017-10-17 | 2017-10-17 | For preventing and administering the long-short pile ruggedized construction and reinforcement means of foundation pit bottom heave |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710962053.5A CN107587511B (en) | 2017-10-17 | 2017-10-17 | For preventing and administering the long-short pile ruggedized construction and reinforcement means of foundation pit bottom heave |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107587511A CN107587511A (en) | 2018-01-16 |
| CN107587511B true CN107587511B (en) | 2019-06-07 |
Family
ID=61053436
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710962053.5A Active CN107587511B (en) | 2017-10-17 | 2017-10-17 | For preventing and administering the long-short pile ruggedized construction and reinforcement means of foundation pit bottom heave |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107587511B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108333331B (en) * | 2018-02-12 | 2020-06-26 | 广西大学 | Method for evaluating stability of rock and soil on overlying and side wall of shallow tunnel in small-kiln goaf |
| CN108487256B (en) * | 2018-03-07 | 2023-09-12 | 中冶集团武汉勘察研究院有限公司 | Reinforced structure and method for deepening and super-digging foundation pit |
| CN110457636B (en) * | 2018-05-07 | 2022-09-16 | 中铁二院工程集团有限责任公司 | Method for determining base uplift amount of rear road foundation of long and short micro-pile reinforced expansive soil foundation |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002061203A (en) * | 2000-06-09 | 2002-02-28 | Ohbayashi Corp | Uneven settlement controlling foundation of structure |
| CN100549303C (en) * | 2006-10-19 | 2009-10-14 | 杨静明 | Reinforcement method of deep layer soft soil foundation |
| CN102011404B (en) * | 2010-11-24 | 2012-07-04 | 温州中城建设集团有限公司 | Pit supporting structure and construction method thereof |
| CN103352468A (en) * | 2013-04-08 | 2013-10-16 | 温州天然工程勘察有限公司 | Method for laying rigid long piles and rigid short piles in deep foundation pit support engineering in thick-sludge soft soil area |
-
2017
- 2017-10-17 CN CN201710962053.5A patent/CN107587511B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN107587511A (en) | 2018-01-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104612162B (en) | A kind of Deep Foundation Pit of Metro Stations excavation construction method | |
| CN108442382B (en) | In-situ protection and enclosure soil-retaining structure for pressure pipeline crossing deep foundation pit and construction method | |
| CN107587511B (en) | For preventing and administering the long-short pile ruggedized construction and reinforcement means of foundation pit bottom heave | |
| CN102094425A (en) | Foundation pit construction method adopting shallow buried depth Larsen steel plate pile as protective cofferdam | |
| CN104676110A (en) | On-site overhanging protection method of high-voltage cable bailey truss under condition of excavation of foundation pit | |
| CN102979039B (en) | Elevated trestle bridge construction method on covering-free steep bare rock in deepwater and rapid stream | |
| CN102430277B (en) | Coarse grid sunk well for physically processing waste water and construction method thereof | |
| CN106812150A (en) | A kind of mountain area steep slope region Road Bridge Pile Foundation construction method | |
| CN108517877A (en) | Miscellaneous fill ultra-deep foundation pit consolidates slip casting combination double-row steel pipe stake supporting construction method | |
| CN105908625A (en) | Construction method for adding frame bridge under existing railway line based on dragging method | |
| CN108532586A (en) | A kind of construction method of garage parking diaphram wall | |
| CN105714769A (en) | Construction method for anti-sliding cast-in-place pile | |
| CN207878473U (en) | Layer depth foundation pit hangs foot stake supporting construction to Tu Yan in combination | |
| CN203049443U (en) | High level trestle structure arranged on steep bare rock of deepwater torrent unsheathed layer | |
| CN100513705C (en) | Underground Beam-Pile Frame Structure for Slope Reinforcement | |
| CN106869138A (en) | A kind of load retaining wall Retaining Structure with Double-row Piles and its foundation ditch excavation method | |
| CN115595993A (en) | Replacement pile structure of tunnel-passing slope slide-resistant pile and construction method | |
| CN104404979A (en) | H-shaped pile slab wall construction method | |
| CN106096162A (en) | A kind of method determining shield support pressure and mathematical model thereof and construction method | |
| CN107165173A (en) | A kind of foundation pit supporting system and its construction method | |
| CN206385525U (en) | A kind of timber structure for preventing the high backfill earthwork from sinking | |
| CN201459749U (en) | Stable structure for construction platform of deep water steel pipe pile | |
| CN105544597B (en) | Suitable for the combination foundation structure and its construction method under Diarrhea lacustrine facies islands and reefs environment | |
| Mangushev et al. | Modern technologies of foundation building in the conditions of weak soils of St. Petersburg | |
| CN110889235A (en) | Underground pile foundation construction engineering design method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 430080 No. 17 metallurgical Avenue, Qingshan District, Hubei, Wuhan Patentee after: MCC Wukan Engineering Technology Co.,Ltd. Address before: 430080 No. 17 metallurgical Avenue, Qingshan District, Hubei, Wuhan Patentee before: WUHAN SURVEYING GEOTECHNICAL RESEARCH INSTITUTE Co.,Ltd. OF MCC |