CN109706940A - Foundation pit servo support system setting method - Google Patents
Foundation pit servo support system setting method Download PDFInfo
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- CN109706940A CN109706940A CN201910145578.9A CN201910145578A CN109706940A CN 109706940 A CN109706940 A CN 109706940A CN 201910145578 A CN201910145578 A CN 201910145578A CN 109706940 A CN109706940 A CN 109706940A
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Abstract
The invention discloses a kind of foundation pit servo support system setting methods, belong to technical field of building construction.The foundation pit servo support system setting method is configured by the way of setting one every two, so-called to set as first of concrete support, second and third road bracing members, the 4th concrete support, the five, the six bracing members ... according to foundation depth and so on every two.The foundation pit servo support being configured using this kind of method, deformation control effect is preferable, after bracing members failure, every two set gone along with sb. to guard him under one set-up mode deformation increase it is minimum, rely on Practical Project, influence of the axle power servo-system difference set-up mode to deformation control of foundation pit is analyzed, the deformation control effect and structure shearing, moment of flexure situation of change of bracing members failure front and back building enclosure have been comprehensively considered, it is final to determine that setting one every two is all best selection.
Description
Technical field
The present invention relates to technical field of building construction more particularly to a kind of foundation pit servo support system setting methods.
Background technique
The using effect of steel support shaft force servo system is largely dependent upon the application dynamics and setting of axial force of the supports
Mode.In the value of bracing members axle power, adaptation to local conditions particular problem is on the one hand wanted to make a concrete analysis of, on the other hand can also referred to
The stress changing rule of conventional steel brace.In the case where axle power applies effectively, axial force of the supports has significantly foundation pit deformation
Effect of contraction.But deep basal pit often has multiple tracks bracing members, the deformation effect of foundation pit and the set-up mode of support are related.
Axle power servo-system is due to can effectively control axial force of the supports thus be widely applied, but working as can not be whole
Servo-system is set or there are foundation pit servo support system when multiple tracks concrete support, how is arranged to go along with sb. to guard him lateral deformation
Control effect is a good problem to study well.
Summary of the invention
The purpose of the present invention is to provide a kind of foundation pit servo support system setting methods, go along with sb. to guard him after bracing members failure
The lateral deformation control effect of structure is preferable.
To achieve the above object, the following technical schemes are provided:
The present invention provides a kind of foundation pit servo support system setting method, the step of the method includes: foundation pit by upper
It is concrete support that first of support is set gradually under, and second support and the support of third road are bracing members, the 4th support
For concrete support, the 5th support and the 6th support are bracing members, and so on.
Further, at least one of bracing members uses automatic servo system.
Further, the automatic servo system is axle power servo-system.
Further, the axle power for taking dual control method to obtain using the bracing members of automatic servo system does not use automatic servo system
The axle power that the bracing members of system take design to provide is pre- value added.
Further, the dual control method includes the following steps:
S1, selection Deformation control value；
S2, it determines construction operating condition, establishes excavation models；
S3, it is predicted according to excavation models, determines building enclosure Amoebida scale value by analyzing, and determine each support
Axle power limit value；
S4, deformation and axial force of the supports coupling, determine and adjust each road and Ge Gen axial force of the supports setting value；
S5, stage excavation simultaneously close off upper layer and correspond to axial force of the supports automatic compensation function；
S6, judge whether each layer deformation meets the requirements, if being unsatisfactory for requiring, enter S7 and enter if meeting the requirements
S9；
S7, this road axial force of the supports is adjusted；
S8, judge whether axial force of the supports has reached axial force of the supports limit value, if not up to, returning to S5, if reaching, entering
S9；
S9, using current axle power value as this road axle power controlling value, using the axle power after the bracing transform of upper layer as upper layer axle power
Controlling value；
S10, axial force of the supports automatic compensation function is opened, until this layer excavates successfully, is excavated into lower layer；
S11, judge whether excavation of foundation pit excavates on earth, if excavating on earth, enter S12 and returned if not excavating on earth
S5；
S12, excavation of foundation pit are completed.
Compared with prior art, foundation pit servo support system setting method provided by the invention, sets one using every two
Mode is configured, it is so-called every two set one be first of concrete support, second and third road bracing members, the 4th concrete branch
Support, the five, the six bracing members ... are according to foundation depth and so on.The foundation pit servo branch being configured using this kind of method
Support, deformation control effect is preferable, after bracing members failure, sets every two and goes along with sb. to guard him deformation under one set-up mode and increase minimum, rely on real
Border engineering analyzes influence of the axle power servo-system difference set-up mode to deformation control of foundation pit, has comprehensively considered bracing members mistake
The deformation control effect and structure shearing, moment of flexure situation of change of effect front and back building enclosure, it is final to determine that it is all best for setting one every two
Selection.
Detailed description of the invention
Fig. 1 is Pudong, station, South Road subway foundation pit floor map in the embodiment of the present invention；
Fig. 2 is Pudong, station, South Road subway foundation pit schematic cross-sectional view in the embodiment of the present invention；
Fig. 3 be the embodiment of the present invention in two layers of underground station pit difference operating condition under wall sidesway figure；
Fig. 4 be the embodiment of the present invention in F3/B3 station pit difference operating condition under wall sidesway figure；
Fig. 5 a is that the concrete support in the foundation pit servo support system in the embodiment of the present invention sets one set-up mode every one；
Fig. 5 b is that the concrete support in the foundation pit servo support system in the embodiment of the present invention sets a set-up mode every two；
Fig. 5 c is that the concrete support in the foundation pit servo support system in the embodiment of the present invention sets one set-up mode every three；
Fig. 6 is to go along with sb. to guard him deformation pattern under the different set-up modes of three kinds of concrete support in the embodiment of the present invention；
Fig. 7 is to go along with sb. to guard him deformation under the different set-up modes of three kinds of concrete support after the bracing members in the embodiment of the present invention fail
Figure；
Fig. 8 a is the building enclosure that concrete supports under three kinds of different set-up modes before the bracing members in the embodiment of the present invention fail
Shear diagram；
Fig. 8 b is the building enclosure that concrete supports under three kinds of different set-up modes after the bracing members in the embodiment of the present invention fail
Shear diagram；
Fig. 9 a is the building enclosure that concrete supports under three kinds of different set-up modes before the bracing members in the embodiment of the present invention fail
Bending moment diagram；
Fig. 9 b is the building enclosure that concrete supports under three kinds of different set-up modes after the bracing members in the embodiment of the present invention fail
Bending moment diagram；
Figure 10 is dual control method schematic diagram in the embodiment of the present invention；
Figure 11 is deep basal pit active control flow chart in the embodiment of the present invention；
Figure 12 a is the floor map of the mechanical model figure in the embodiment of the present invention；
Figure 12 b is the diagrammatic cross-section of the mechanical model figure in the embodiment of the present invention；
Figure 13 a is the plan view of the foundation pit space-load state in the embodiment of the present invention；
Figure 13 b is the sectional view of the foundation pit space-load state in the embodiment of the present invention；
Figure 13 c is the plan view of the foundation pit plane strain state in the embodiment of the present invention；
Figure 13 d is the sectional view of the foundation pit plane strain state in the embodiment of the present invention；
Shear stress schematic diagram when Figure 14 a is space-load in the embodiment of the present invention between building enclosure；
Shear stress schematic diagram when Figure 14 b is space-load in the embodiment of the present invention between the soil body；
Figure 15 a is the shear stress schematic diagram in the embodiment of the present invention under plane strain between building enclosure；
Figure 15 b is the shear stress schematic diagram in the embodiment of the present invention under plane strain between the soil body；
Figure 16 is that the flood axial force of the supports in the embodiment of the present invention based on deformation adjusts schematic diagram.
Appended drawing reference: the area 1-A-1 foundation pit；The area 2-B foundation pit；The area 3-A-2 foundation pit；First of 4- support；The support of 5- second；
The support of 6- third road；7- the 4th is supported；8- the 5th is supported；9- the 6th is supported.
Specific embodiment
To keep the technical problems solved, the adopted technical scheme and the technical effect achieved by the invention clearer, below
It will be described in further detail in conjunction with technical solution of the attached drawing to the embodiment of the present invention, it is clear that described embodiment is only
It is a part of the embodiment of the present invention, instead of all the embodiments.Based on the embodiments of the present invention, those skilled in the art exist
Every other embodiment obtained under the premise of creative work is not made, shall fall within the protection scope of the present invention.
Present embodiments provide a kind of foundation pit servo support system setting method, the support that foundation pit is arranged from top to bottom are as follows:
First is concrete support, and second and third road are bracing members, and the 4th is concrete support, and the 5th and the 6th is
Bracing members, and so on.
Further, at least one of bracing members use automatic servo system, and so-called automatic servo system is axle power servo system
System.Specifically, the axle power for taking dual control method to obtain using the bracing members of automatic servo system does not use the steel branch of automatic servo system
The axle power that support takes design to provide is pre- value added.
The using effect of steel support shaft force servo system is largely dependent upon the application dynamics and setting of axial force of the supports
Mode.In the value of bracing members axle power, adaptation to local conditions particular problem is on the one hand wanted to make a concrete analysis of, on the other hand can also referred to
The stress changing rule of conventional steel brace.
In the case where axle power applies effectively, axial force of the supports has apparent effect of contraction to foundation pit deformation.But deep base
Often there are multiple tracks bracing members in hole, and the deformation effect of foundation pit is also related to the set-up mode of support, at present there has been no correlation analysis, because
It is necessary to study the deformation control of foundation pit effects under different set-up modes for this.
(1) model foundation
By taking the foundation pit of Shanghai City Pudong, station, South Road as an example, the application for carrying out steel support shaft force servo system is illustrated.
Pudong, station, South Road is located in Lujiazui nucleus, and foundation pit is laid along Pudong Avenue East and West direction, rides i.e. ink road.It is proposed
Station distribution of strata is as follows: 1. 1 miscellaneous fill, 2. 1 silty clay, 3. very soft sill clay, 3. presss from both sides sandy silt, 4. Muddy Bottoms
Clay, 5. 1 silty clay, 6. silty clay, 7. 1-2 sandy silt, 7. 2 flour sand.Station main body Foundation Pit bottom is located at 5. 1 layer of powder
In matter clay, enclosure wall toe of wall bottom is located at the 7. in 2 layers of flour sand.
Foundation pit enclosure form is the diaphram wall of 1.0m thickness 46m depth.Standard paragraphs 6 support, first of support 4 and the 4th
Road support 7 is concrete support (1000*800,1500*1200), and the 5th support 8 is supportted for 800*20 steel pipe, second support 5,
Third road support 6 and the 6th support 9 are 609*16 steel pipe support (Fig. 2).
Environment locating for foundation pit is complicated, and north side is parallel to the building of going on board of foundation pit arrangement, development of Pudong exhibition hall etc. and builds
Build object, southern side is parallel to the jug spring cell of foundation pit arrangement, buildings such as Hua Da tall building forever；And AT STATION south and north flanks have it is numerous
Big inch line is closely close to foundation pit.
In view of station main body foundation pit is longer, and across being ink road, three foundation pits of Pudong's South Road station owner's body point are applied respectively
Work is followed successively by the area A-1 foundation pit 1, the area B foundation pit 2, the area A-2 foundation pit 3 (such as Fig. 1) from West to East.Due to 3 surrounding enviroment of the area A-2 foundation pit
The most complicated, difficulty of construction is maximum, therefore the construction area B foundation pit 2, then the construction area A-1 foundation pit 1 in advance, the area A-2 base of finally constructing
It cheats in the construction of the area 3, Bing A-2 foundation pit 3 and uses axle power servo-system, to meet Deformation control requirement.
For comparing calculation, it is assumed that separately have two layers of underground station, go along with sb. to guard him depth 33m, foundation depth 18m；In digging process
If five supports, first of support is that C40 concrete supports, second and third road is the support of 609 × 16 steel pipes, and fourth, fifth is 800 × 20
Steel pipe support, geologic parameter is the same as the Pudong's South Road area A-2 foundation pit 3.Using native constitutive model is hardened, basic calculating model, soil layer are established
Parameter is as shown in table 1, table 2.
(2) under different servo system set-up mode two layers of underground station deformation control effect
In order to simulate use bracing members automatic servo system after on the issuable influence of building enclosure sidesway, the above section
Imaginary foundation pit is to rely on, and selection establishes finite element model with the different operating conditions that axial force of foundation pit steel support compensates respectively:
(1) 1-bracing members of operating condition all use automatic servo system；
(2) 2-half of operating condition bracing members use automatic servo system, are respectively there are four types of sub- operating condition, sub- operating condition 1: the second,
Three supports use automatic servo；The sub- support of operating condition 2: fourth, fifth uses automatic servo；Sub- operating condition 3: the second, five supports
Using automatic servo；Sub- operating condition 4: the support of third and fourth road uses automatic servo；
(3) 3-bracing members of operating condition interval uses automatic servo system, is respectively there are two types of sub- operating condition, sub- operating condition 1: the second,
Four supports use automatic servo；Sub- operating condition 2: third, five supports use automatic servo；
(4) certain single road bracing members of operating condition 4-use automatic servo system, there are four types of sub- operating condition: be respectively second and third,
Four, five supports compensate axle power respectively；
(5) operating condition 5-does not use automatic servo system.
In above-mentioned various operating conditions, the axle power (as shown in table 1) for taking dual control method to obtain using the support of automatic servo system, not
The axle power that the support of use takes design to provide is pre- value added.
1 axial force of the supports table of table
| Dual control method axle power/kN/m | Pre- value added/kN/m | |
| First of concrete support | / | / |
| Second bracing members | -420 | -310 |
| Third road bracing members | -550 | -310 |
| 4th bracing members | -800 | -370 |
| 5th bracing members | -900 | -200 |
The ground wall sidesway for obtaining various situations is as shown in Table 2 and Fig. 3.Obviously, whole bracing members use automatic servo system
Operating condition under, the sidesway of building enclosure can be substantially reduced；Half is using under the operating condition of automatic servo, and twice support in bottom is using certainly
The reduction of sidesway becomes apparent from when dynamic servo；Interval uses two kinds of operating conditions of automatic servo, and third, five bracing members are used and watched automatically
The reduction of sidesway becomes apparent from when taking；And used on certain single road bracing members in four kinds of operating conditions of automatic servo, in the 5th steel
It is relatively smaller that sidesway is gone along with sb. to guard him when in support using automatic servo.On the whole, bracing members all use the effect of automatic servo system
Fruit is best, and what half used takes second place, and is spaced existing again of using, the effect that certain single road uses is worst.
Ground wall sidesway situation under the station pit difference operating condition of two layers of 2 underground of table
(3) under different servo system set-up mode F3/B3 station deformation control effect
It is to rely on the F3/B3 station at Pudong, station, South Road, the different operating conditions point compensated for same axial force of foundation pit steel support
Do not establish finite element model:
(1) operating condition 1 --- bracing members all use automatic servo system；
(2) operating condition 2 --- half bracing members use automatic servo system, are respectively sub- operating condition 1: the there are four types of sub- operating condition
Two, three supports use automatic servo；The sub- support of operating condition 2: the five, six uses automatic servo:；Sub- operating condition 3: third, five
Support uses automatic servo；The sub- support of operating condition 4: the second, six uses automatic servo；
(3) operating condition 3 --- bracing members interval uses automatic servo system, is respectively sub- operating condition 1: the there are two types of sub- operating condition
Two, five supports use automatic servo；Sub- operating condition 2: third, six supports use automatic servo；
(4) operating condition 4 --- certain single road bracing members use automatic servo system, and there are four types of sub- operating conditions: respectively second,
Three, five, six supports compensate axle power respectively.
In above-mentioned various operating conditions, the axle power for taking dual control method to obtain using the support of automatic servo system, the support not used
The axle power for taking design to provide is pre- value added (table 3).
3 axial force of the supports table of table
| Dual control method axle power/kN/m | Pre- value added/kN/m | |
| First of concrete support | / | / |
| Second bracing members | -420 | -250 |
| Third road bracing members | -550 | -385 |
| The support of 4th concrete | / | / |
| 5th bracing members | -1000 | -560 |
| 6th bracing members | -900 | -340 |
Calculated result under different operating conditions is arranged into such as table 4, Fig. 4.It is obvious that being still support all using automatic servo system
The effect of system is best.
Ground wall sidesway situation under 4 F3/B3 station pit difference operating condition of table
(4) set-up mode is supported based on the servo of system safety and Deformation control
(1) subregion setting principle
As the above analysis, the control effect of servo-system and its setting method, setting quantity are closely related, participate in adjusting
The whole more control effects of resilient support amount are better；Change can also be improved by optimal setting mode in the case where set amount is certain
Shape control effect.
It is contemplated that the reliability of bracing members, a certain number of concrete supports of setting are generally required in ultra-deep foundation pit, are adopted
The region for being divided into several relatively independent the bracing members being continuously arranged is supportted with concrete, subregion setting is formed, improves base
The degree of safety of hole system.But concrete Construction of Supporting will increase and go along with sb. to guard him deformation, while as rigid constraint point, concrete axial force of the supports cannot
It is adjusted, cannot be formed with adjacent supports and cooperate with load, this affects deformation control effect again.Therefore bracing members and concrete support
Subregion set-up mode be conflict for deep pit monitor and Deformation control, it is necessary to establish watching of both can taking into account
Dress system subregion setting principle.
The subregion setting principle of ultra-deep foundation pit servo-system be can by multiple tracks servo support system it is continuous arrangement come
Effectively control foundation pit deformation, and can ensure that the peace of foundation pit and surrounding enviroment after the servo-system whole failure between the support of twice concrete
Quan Xing.The Deformation control and deep pit monitor that will be discussed respectively under different subregions set-up mode below.
(2) subregion set-up mode
1) concrete support sets one every one
For deep basal pit, must be provided with concrete support first, every one set one be first of concrete support,
Second bracing members, third road concrete support, the 4th bracing members ... are shown in Fig. 5 a according to foundation depth and so on.
2) concrete support sets one every two
For deep basal pit, must be provided with concrete support first, every two set one be first of concrete support,
Second and third road bracing members, the 4th concrete support, the five, the six bracing members ... are shown in figure according to foundation depth and so on
5b。
3) concrete support sets one every three
For deep basal pit, must be provided with concrete support first, every three set one be first of concrete support,
Second and third, four bracing members, the 5th concrete support, the six, the seven, eight bracing members ... according to foundation depth with such
It pushes away.See Fig. 5 c.
Concrete support sets a collaboration load for being unfavorable for bracing members every one, and deformation control effect is worst；Concrete support sets one every two
It is preferable with a deformation control effect is set every three, it needs to comprehensively consider foundation pit actual depth with depth is gone along with sb. to guard him in practical application to select.
In terms of Deformation control angle, concrete support it is fewer deformation it is smaller, but bracing members failure after instability of foundation pit risk it is also bigger.
From the angle controlled risk, the setting standard of concrete support can set about from control deep pit monitor and surrounding enviroment protection,
Foundation pit is still safe when bracing members i.e. between concrete supports all fail, and surrounding enviroment are controllable.For 1m wall, every
Two set first is that contradictory equalization point；And for 1.2m wall, it is also feasible for setting one every three.
Still by taking three layers of station as an example, it is respectively calculated in a model to setting one every one, set one every two and set one every three, it is right
Than the deformation of foundation pit under different set-up modes.For comparison three kinds of set-up modes under foundation pit deformation control effect, every two
It is specific as shown in table 5 if applying axle power on the basis of one axial force of the supports:
Axial force of the supports/kN/m under the different set-up modes of table 5
| One is set every one | One is set every two | One is set every three | |
| 1# support | / | / | / |
| 2# support | -420 | -420 | -420 |
| 3# support | / | -550 | -550 |
| 4# support | -550 | / | -1000 |
| 5# support | / | -1000 | / |
| 6# support | -1000 | -880 | -880 |
It is as shown in Figure 6 that deformation is gone along with sb. to guard him under three kinds of set-up modes.
By deformation curve figure it is found that every one set one deformation control effect it is worst, every two set one with every three set a control effect
Fruit gap is little, and it is larger that the latter's later period deforms growth.
Deformation is gone along with sb. to guard him after bracing members failure between concrete is supported to arrange in Fig. 7.After bracing members failure, one setting is set every two
Deformation is gone along with sb. to guard him under mode and increases minimum, is set every three and is gone along with sb. to guard him deformation under one set-up mode much larger than setting one every two and set one every one.
By under three kinds of different set-up modes, after bracing members failure the growth pattern of wall maximum distortion arrange in table 6.Every
Three set and go along with sb. to guard him deformation growth rate for the moment up to 128%, far more than every one set one with set one every two.
Deformation growth pattern is gone along with sb. to guard him after the failure of 6 bracing members of table
Bracing members failure front and back concrete axial force of the supports variation under three kinds of different set-up modes is arranged in table 7.Bracing members lose
After effect, concrete support is all pressured state, and pressure increase is significant.It sets every one one close with an amplification is set every two, is set first every three
Amplification is larger.
7 bracing members of table failure front and back concrete axial force of the supports variation/kN/m
The shearing of building enclosure, moment of flexure situation arrange in Fig. 8 a, Fig. 8 b, Fig. 9 a and Fig. 9 b before and after bracing members are failed.
As seen from the figure, under three kinds of set-up modes, the variation tendency of building enclosure shearing is almost the same；One is set every one and sets a moment of flexure every two
Change also almost the same, and sets that building enclosure shearing under one arrangement is maximum, and moment and its variation are also maximum every three.
From analysis it is found that for three layers of station pit in this article, bracing members failure front and back comprehensively considers deformation control
Effect and building enclosure processed shearing, moment of flexure situation of change, setting one every two is all best selection.
Practical Project is relied on, influence of the axle power servo-system difference set-up mode to deformation control of foundation pit is analyzed, it is comprehensive
Consider the deformation control effect and structure shearing, moment of flexure situation of change of bracing members failure front and back building enclosure, it is final determine every
Two to set one be all best selection.
Detailed process is as follows for above-mentioned dual control method:
Since the cost of base pit engineering zero shift control is excessive, allow building enclosure that certain change occurs in practice
Deformation control index has been previously set often according to environmental protection needs in engineering in shape.Currently used bracing members specification simultaneously
Generally diameter 609mm and diameter 800mm, their ultimate bearing capacity can be obtained according to pressure bar stabilization theoretical calculation,
The axle power supported is finite value, in the case where the two all finite values, using floor structure methods in common finite element
The axle power for meeting above-mentioned requirements is acquired using trial and error procedure, and obtains the internal force of building enclosure, to realize pair of intensity and rigidity
Control, this method are referred to as " dual control method " (as shown in Figure 10).First layer earth excavation, the second layer are followed successively by figure from left to right
Earth excavation, third layer earth excavation ... and so on, wherein f < [f], F < [N] are displaced at first of supporting depth and are less than
Deformation control value；f1< [f], F1< [N], f2< [f], F2< [N], displacement is less than Deformation control value at the first and second supporting depth,
First and second axial force of the supports is less than axle power limit value；f1< [f], F1< [N], f2< [f], F2< [N], f3< [f], F3< [N], first~
Displacement is less than Deformation control value at three supporting depths, and the first~tri- axial force of the supports is less than axle power limit value.
Active control process of the present embodiment based on floor structure methods is as follows:
1) since floor structure methods have fully considered the interaction of underground structure and surrounding formation, in conjunction with specific construction
Process can sufficiently simulate underground structure and surrounding formation in the structural internal force and surrounding formation of each construction operating condition
Deformation can more meet engineering reality, therefore can be used for the active control of foundation pit.
2) foundation pit active control includes the following contents: determining analysis software and constitutive model, establishes model-parameter knowledge
Not-correction model, the dbjective state for determining foundation pit, the Dynamic Simulation Analysis based on work progress, control is implemented, analysis is predicted.
3) it according to the control method of above-mentioned axial force of the supports, building enclosure internal force and deformation, present embodiments provides a kind of soft
Native subway foundation pit excavation construction method, wherein the active control process of base pit engineering is as shown in figure 11:
S1: the Deformation control requirement of clear protected object, for multiple protected objects, with the protection pair of coverage inner periphery
The most tight of elephant requires to be used as Deformation control value；
S2: it determines construction operating condition, establishes excavation models, according to the actual situation, specify each operating condition in work progress, build
Found corresponding excavation models, it is ensured that excavation models are corresponding with construction operating condition, and can be adapted with practice of construction；
S3: forecast analysis foundation pit deformation determines building enclosure Amoebida scale value and each axial force of the supports limit value, according to foundation pit
Model is predicted, can first be predicted whether support system can satisfy requirement, adjustable if cannot meet the requirements
Support construction, until meeting the requirements；Building enclosure Amoebida scale value is determined by analyzing, and determines each axial force of the supports limit value,
Building enclosure Amoebida scale value determines that axial force of the supports limit value is according to compression bar principle according to periphery protected object and excavation of foundation pit depth
To determine；
S4: deformation and axial force of the supports coupling determine and adjust each road and Ge Gen axial force of the supports setting value；
S5: stage excavation simultaneously closes off upper layer and corresponds to bracing members (if any) axle power automatic compensation function；
S6: judging whether each layer deformation meets the requirements, and if the requirements are not met for each layer deformation, then enters step S7, each layer
If deformation is met the requirements, S9 is entered step；
S7: this road axial force of the supports is adjusted；
S8: judging whether axial force of the supports has reached axial force of the supports limit value, if not up to axial force of the supports limit value, returns to step
Rapid S5 enters step S9 if reaching axial force of the supports limit value；
S9: using current axle power value as this road axle power controlling value, using the axle power after the bracing transform of upper layer as upper layer axle power
Controlling value；
S10: opening axial force of the supports automatic compensation function, completes until this layer excavates, and excavates into lower layer；
S11: judging whether excavation of foundation pit excavates on earth, if excavating on earth, enters step S12, if not excavating on earth,
Return step S5；
S12: excavation of foundation pit is fully completed.
Wherein, the mechanical model of (1) Metro Deep Excavation design is as follows:
For the strips foundation pit such as subway, it is flat that the hypothesis that when design of foundation pit is typically based on plane strain is reduced to it two dimension
Surface model (as shown in Figure 12 a-12b).According to plane strain it is assumed that
τxz=τyz=0；
σZ=μ (σx+σy)；
It is not strained in Z-direction, but its stress σzAnd it is not zero.
(2) the mechanical state variation of weak soil Metro Deep Excavation work progress
Since the earthwork is that piecemeal excavates, support is set up by root, the mechanical state of foundation pit is by initial spatial character
Gradually change (as shown in Figure 13 a-13d) to the mechanical state of plane strain, i indicates the gradient of margin of foundation pit in figure.That is foundation pit
Mechanical model in work progress should be three-dimensional space problem, rather than plane strain problems.
I.e. in the three-dimensional space problem of foundation pit construction, the γ with the soil body is gone along with sb. to guard himxzBe not zero so that building enclosure with
τ can be transmitted between the soil bodyxz(as shown in Figure 14 a-14b), in figure, q is overcharge on ground.
When meeting plane strain hypothesis, the shear stress τ of building enclosure and the soil bodyxz=τyz=0, i.e., the soil body with go along with sb. to guard him
Shear load is not transmitted between structure (as shown in Figure 15 a-15b).
(3) based on the Deformation control strategy of foundation pit construction mechanical model
In three-dimensional space mechanical model, the presence with soil body transverse shear deformation is gone along with sb. to guard him, increases axial force of the supports to soil
The coverage of body deformation, reduces axle power to the control effect of deformation.The axial force of the supports acted in building enclosure is more, more
Close to plane strain state, foundation pit mechanical response by go along with sb. to guard him influenced with soil body transverse shear deformation it is smaller, otherwise it is bigger.That is base
The space mechanics state of hole construction makes the adjustment effect of a small amount of axial force of the supports be less than the adjustment effect of flood axial force of the supports, supports
Axle power is more, notional result with to practice monitoring data closer.Therefore when deformation result in digging process and control target are different
When cause, the control for going along with sb. to guard him deformation can be realized by the adjustment of flood axial force of the supports after this layer of earth excavation completion, support are set up
It makes (as shown in figure 16), wherein the adjustment of flood axial force of the supports meets: N1=N+ Δ N, the adjustment for going along with sb. to guard him deformation meet: δl→
δ1', δl'=δ1-Δδ。
Building enclosure Amoebida scale value is determined in S3 and Ge Gen axial force of the supports limit value is to realize base by influence matrix method
Deformation control is cheated, what influence matrix was calculated by the iteration to linear elasticity state.
For line elastomer, the analysis method that influence of the axle power adjustment to deformation can use structural mechanics carries out essence
True analysis, if influence matrix method is to realize the effective ways of deformation control of foundation pit.When configuration state be in it is non-linear when, can lead to
The continuous iteration to linear elasticity state is crossed to realize the solution of nonlinear problem.
In the calculating process of influence matrix method, it is thus necessary to determine that matrix be respectively modulated vector, apply adjust vector sum influence to
Amount.
Wherein, modulated vector is that column vector composed by m independent element, these elements one on section are concerned about in works
As by component force on cross-section or displacement form, they receive adjustment during tone pitch, to reach certain expectation state,
Modulated vector is denoted as D,
D=(d1, d2..., dm)T；
Tuning amount is applied to specify 1 (1≤m) independent element institute group of the implementable adjustment to change modulated vector in works
At column vector, apply tuning amount and be denoted as X,
X=(x1, x2..., xl)T；
Influencing vector is to apply j-th of element x j in tuning amount unit change occurs, and causes the change vector of modulated vector D,
Vector is influenced to be denoted as:
Aj=(a1j, a2j..., amj)T；
Influence matrix is 1 applies tuning amount and occurs unit change respectively, and caused 1 influences vector and is arranged successively to be formed
Matrix, influence matrix are denoted as:
In influence matrix, element may be one in the mechanical quantities such as internal force, displacement, and influence matrix is these mechanical quantities
Mixing composition；If the n vector for being concerned about that desired internal force on section, displacement form is { E } in structure, it is concerned about existing in section
Corresponding vector is { F }d, adjustment calculation is exactly to reach configuration state at care section by changing the n mechanical quantities for applying tune member
To { E }, at this point, the modulated vector of structure are as follows: { D }={ E }-{ F }d, when structure meets linear superposition, have: [A] { X }={ D }.
For linear structure, influence matrix method computational accuracy is higher.
And the presence of soil spring makes above-mentioned model belong to nonlinear state, in order to solve nonlinear organization, influence matrix
Accurate calculated result can be obtained by iterative technique, iteration specifically calculates that steps are as follows:
1. carrying out first time calculating by linear structure first, acquired according to A by tuning amount { X }0；
2. by { X }0It acts on and carries out forward-analysis method in structure, acquire { X }0Desired value { E } under effect0, to calculate
It adjusts difference value vector { Δ E }={ E }-{ E }0；
3. new influence matrix A is calculated, using { Δ E } as tone pitch vector, by [A] based on the structure formed in 2.
{ Δ X }={ Δ E } acquires { Δ X }；
4. enabling { X }={ X }0+ { Δ X } repeats 2.~calculating 3., when { Δ E } is less than specification error ε { X }0It is exactly real
Border is by the approximate solution of tuning amount { X }.
Influence matrix method is as follows in the adjustment of foundation pit axle power and the application in Deformation control:
In base pit engineering, applying tuning amount is axial force of the supports, and modulated vector can be concerned about for axial force of the supports, building enclosure to be cut
Internal force or displacement at face, that is, the adjustment by applying tuning amount axial force of the supports realize axial force of the supports, building enclosure deformation
With the adjustment of internal force；
Enable { F }dThe internal force respectively supported after applying for a preceding brace pre axial force is 0 when the 1st secondary axes power applies；A is to influence square
Battle array；{ X } is the load that each support need to apply, and the sum of the load and each existing internal force of support are that axle power applies controlling value；{E}
For each axial force of the supports of design requirement, then there is { F }d+ [A] { X }={ E }；
For foundation pit along for building excavation, due to { F }d=0, it is support shaft by { X } that influence matrix iteration acquires
Power, since support system gradually forms in Excavation Process, influence matrix A is upper triangular matrix, when excavation of foundation pit knot
For beam axle power adjusts again, structural system has been basically formed, at this time { F }d≠ 0, influence matrix A are Man Zhen, and element composition can
It is formed in any order, { X } is unrelated with support order in this case, but is at this time axis by { X } that influence matrix A is directly acquired
Power increment rather than the application value of axle power, and axle power application value then needs to be solved again according to sequence of construction.
As long as external load is certain, the displacement target of specified location, internal force target are determined, can be real by influence matrix method
Now the optimization of building enclosure displacement, internal force and axial force of the supports is calculated, to realize the intensity of design of foundation pit, rigidity dual control
System.In the case where building enclosure self-strength is met the requirements, the modulated vector in influence matrix method can be further simplified, i.e.,
Modulated vector only considers the axle power of the displacement and bracing members of the building enclosure at support, and applying tune amount is bracing members axle power.Influence matrix
Method needs, in conjunction with load structure method, to can be used for professional ground calculation procedure by being programmed to.
Note that the above is only a better embodiment of the present invention and the applied technical principle.It will be appreciated by those skilled in the art that
The invention is not limited to the specific embodiments described herein, be able to carry out for a person skilled in the art it is various it is apparent variation,
It readjusts and substitutes without departing from protection scope of the present invention.Therefore, although being carried out by above embodiments to the present invention
It is described in further detail, but the present invention is not limited to the above embodiments only, without departing from the inventive concept, also
It may include more other equivalent embodiments, and the scope of the invention is determined by the scope of the appended claims.
Claims (5)
1. a kind of foundation pit servo support system setting method, which is characterized in that the step of the method include: foundation pit from top to bottom
Setting gradually first of support (4) is concrete support, and second supports (5) and third road to support (6) for bracing members, the 4th
Supporting (7) is concrete support, and the 5th support (8) and the 6th support (9) they are bracing members, and so on.
2. foundation pit servo support system setting method according to claim 1, which is characterized in that at least one of bracing members is adopted
Use automatic servo system.
3. foundation pit servo support system setting method according to claim 2, which is characterized in that the automatic servo system
For axle power servo-system.
4. foundation pit servo support system setting method according to claim 2, which is characterized in that use automatic servo system
Bracing members take dual control method obtain axle power, using automatic servo system bracing members take design provide axle power it is pre- value added.
5. foundation pit servo support system setting method according to claim 4, which is characterized in that the dual control method includes such as
Lower step:
S1, selection Deformation control value；
S2, it determines construction operating condition, establishes excavation models；
S3, it is predicted according to excavation models, determines building enclosure Amoebida scale value by analyzing, and determine each axial force of the supports
Limit value；
S4, deformation and axial force of the supports coupling, determine and adjust each road and Ge Gen axial force of the supports setting value；
S5, stage excavation simultaneously close off upper layer and correspond to axial force of the supports automatic compensation function；
S6, judge whether each layer deformation meets the requirements, if being unsatisfactory for requiring, enter S7, if meeting the requirements, enter S9；
S7, this road axial force of the supports is adjusted；
S8, judge whether axial force of the supports has reached axial force of the supports limit value, if not up to, returning to S5, if reaching, enter S9；
S9, using current axle power value as this road axle power controlling value, using the axle power after the bracing transform of upper layer as upper layer axle power control
Value；
S10, axial force of the supports automatic compensation function is opened, until this layer excavates successfully, is excavated into lower layer；
S11, judge whether excavation of foundation pit excavates on earth, if excavating on earth, enter S12 if not excavating on earth and return to S5；
S12, excavation of foundation pit are completed.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111910648A (en) * | 2020-08-20 | 2020-11-10 | 同济大学 | Intelligent and rapid installation method for foundation pit servo support |
| CN112926110A (en) * | 2021-01-22 | 2021-06-08 | 中铁广州工程局集团深圳工程有限公司 | Real-time visual early warning method for risks in construction process of subway station |
| CN113152476A (en) * | 2021-05-10 | 2021-07-23 | 中铁九局集团第六工程有限公司 | Excavation construction method for soft geological foundation pit of existing line station |
| CN114908769A (en) * | 2022-05-23 | 2022-08-16 | 上海建工一建集团有限公司 | Construction method for actively regulating and controlling concrete support servo axial force of foundation pit |
| CN115094963A (en) * | 2022-08-01 | 2022-09-23 | 上海建工一建集团有限公司 | Servo concrete supporting axial force active optimization method considering spatial effect |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101871214A (en) * | 2009-09-11 | 2010-10-27 | 朱奎 | Foundation pit support and construction method for cement mixing pile inserted with Y type precast pile |
| CN102535479A (en) * | 2012-03-09 | 2012-07-04 | 同济大学建筑设计研究院(集团)有限公司轨道交通与地下工程设计分院 | Design method for controlling deformation of deep foundation pit by using axial force servo system of steel support |
| CN202626999U (en) * | 2012-03-09 | 2012-12-26 | 同济大学建筑设计研究院(集团)有限公司轨道交通与地下工程设计分院 | Foundation trench support system adopting active regulation-control deformable design method |
| CN107142947A (en) * | 2017-04-28 | 2017-09-08 | 上海隧道工程有限公司 | Using displacement as the axial force of the supports servo-drive system and its investigating method of servo target |
-
2019
- 2019-02-27 CN CN201910145578.9A patent/CN109706940B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101871214A (en) * | 2009-09-11 | 2010-10-27 | 朱奎 | Foundation pit support and construction method for cement mixing pile inserted with Y type precast pile |
| CN102535479A (en) * | 2012-03-09 | 2012-07-04 | 同济大学建筑设计研究院(集团)有限公司轨道交通与地下工程设计分院 | Design method for controlling deformation of deep foundation pit by using axial force servo system of steel support |
| CN202626999U (en) * | 2012-03-09 | 2012-12-26 | 同济大学建筑设计研究院(集团)有限公司轨道交通与地下工程设计分院 | Foundation trench support system adopting active regulation-control deformable design method |
| CN107142947A (en) * | 2017-04-28 | 2017-09-08 | 上海隧道工程有限公司 | Using displacement as the axial force of the supports servo-drive system and its investigating method of servo target |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111910648A (en) * | 2020-08-20 | 2020-11-10 | 同济大学 | Intelligent and rapid installation method for foundation pit servo support |
| CN112926110A (en) * | 2021-01-22 | 2021-06-08 | 中铁广州工程局集团深圳工程有限公司 | Real-time visual early warning method for risks in construction process of subway station |
| CN112926110B (en) * | 2021-01-22 | 2024-05-07 | 中铁广州工程局集团深圳工程有限公司 | Real-time visual early warning method for risk in subway station construction process |
| CN113152476A (en) * | 2021-05-10 | 2021-07-23 | 中铁九局集团第六工程有限公司 | Excavation construction method for soft geological foundation pit of existing line station |
| CN114908769A (en) * | 2022-05-23 | 2022-08-16 | 上海建工一建集团有限公司 | Construction method for actively regulating and controlling concrete support servo axial force of foundation pit |
| CN114908769B (en) * | 2022-05-23 | 2024-02-06 | 上海建工一建集团有限公司 | Construction method for actively regulating foundation pit by servo axial force of concrete support |
| CN115094963A (en) * | 2022-08-01 | 2022-09-23 | 上海建工一建集团有限公司 | Servo concrete supporting axial force active optimization method considering spatial effect |
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