A kind of rich water soft clay area deep basal pit covered back-digging construction method
Technical field
The present invention relates to engineering construction technology field, in particular to a kind of rich water soft clay area deep basal pit covered back-digging
Construction method.
Background technique
Deep-foundation pit engineering refers to that earth excavation, the dewatering project of the foundation pit (slot) of cutting depth 5m or more, excavation of foundation pit are
A comprehensive engineering roadblock in foundation construction and high-rise basement construction, many problems being related in soil mechanics, simultaneously
It is related to the collective effect problem of soil with supporting construction, construction method and technology are extremely important.Carrying out excavation
When, open-cut and lid excavation construction are generally included, open-cut refers to first all excavating the rock of tunnel site (soil) body, so
After build barrel, portal, then the construction method backfilled, lid excavation construction is after being excavated to certain depth downwards by ground, will
Top closed, remaining lower part engineering is constructed under closed top cover.
When rich water soft clay area carries out deep foundation pit construction, such as fruit structure design, earth excavation machine drop level of ground water etc.
It is improper to manage, it is easy to cause that the earthwork collapses and wait adverse effects, serious consequence is hardly imaginable.The prior art rich water soft clay area into
When row deep foundation pit construction, have a problem in that
1, it is difficult to determine reasonable, effective construction method, leads to that there are security risks, while construction efficiency is low;
2, since rich water soft clay area includes silt clay layer and farinose argillic horizon, bearing capacity of foundation slab is low, the bottom of at
Support has bad luck, sets up the job very difficults such as support when constructing on plate;
3, soil is filled in foundation pit, lifting when soil carries out cycle operation, since construction method and sequence be not right, causes to make
Industry efficiency is lower.
Summary of the invention
It is an object of the invention to: overcome the prior art when rich water soft clay area carries out deep foundation pit construction due to construction party
The low problem of method incomplete caused security risk and construction efficiency, provides a kind of rich water soft clay area deep basal pit lid digging
Reversed construction method, this method sets up bracing members frame during covering and digging using lid excavation construction, while carrying out construction of bottom plates and mixing
Solidifying soil casting work, and side wall, column and top board construction are carried out, solve safety issue existing in the prior art, this is applied
Work method is fast and effective, constructs especially suitable for rich water soft clay area dell, has biggish application value.
In order to achieve the above-mentioned object of the invention, the present invention provides following technical schemes:
A kind of hydrous fluids soft clay area deep basal pit covered back-digging construction method sets deep basal pit as four-layer structure, wherein bearing
One layer and minus two layers uses open-cut, and minus three layers and minus four layers are lid excavation construction, and ground is provided with the support of the 1st concrete, on ground
Be disposed between face and negative one layer the 2nd support and the 3rd support, negative one layer and it is two layers minus between be disposed with the 4th
Road support and the 5th support, covered back-digging construction includes following multiple steps:
A, when excavation of foundation pit to minus two layers of position, using clay model, minus two layers of underplate concrete, and reserved side wall construction are poured
Seam;
B, after minus two layers of bottom plate reaches design strength requirement, lid digs the earthwork of minus two layers of bottom plate lower position, excavates extremely
The 6th support is set up when setting Support Position, is excavated to negative Tipple Bottom Board position, and be poured negative Tipple Bottom board concrete;
C, after negative Tipple Bottom plate reaches design strength requirement, lid digs the earthwork of negative Tipple Bottom plate lower position, excavates extremely
The 7th support is set up when setting Support Position, is excavated to bottom plate position, and bottom board concrete;
D, after base plate strength reaches design strength requirement, the 7th support is removed, the minus four layers of side wall of construction and minus four layers are stood
Column;
E, after minus four layers of side wall intensity up to after design requirement, removing the 6th support, and it is minus three layers of side wall of constructing, three layers minus
Column;
F, after minus three layers of side wall intensity reaches design requirement, the 4th and the 5th support is removed, minus two layers of side wall of constructing is born
Two layers of column and negative one layer bottom plate;
G, after minus two layers of side wall, negative one layer base plate strength reach design requirement, the 2nd and the 3rd support is removed, construction is negative
One layer of side wall, negative one layer column and top plate;
H, after negative one layer side wall, strength of roof reach design requirement, first of concrete support is removed.
Aforesaid way is taken, by taking above-mentioned covered back-digging construction method, i.e. erection bracing members frame during covering digging,
Construction of bottom plates and concrete casting work are carried out simultaneously, and carries out side wall, column and top board construction, are solved and are deposited in the prior art
Safety issue, the construction method is fast and effective, especially suitable for rich water soft clay area dell construct.
It preferably, include earthwork construction in rich water soft clay area deep basal pit covered back-digging construction method, earthwork construction includes
Following steps:
I1, foundation pit is divided into four units along foundation pit length direction, including first unit, second unit, third unit and
Unit the 4th, and soil outlet is set in each unit, it is included in first unit and the first soil outlet is set, in second unit setting the
Two soil outlets are arranged third soil outlet in third unit, and configure crawler type grabbing arrangement, and the third soil outlet is from third list
Member extends to Unit the 4th;
I2, longitudinal layered excavation, including the 9th layer, the tenth layer, eleventh floor, Floor 12, the 13rd are carried out to foundation pit
Layer and the 14th layer, described 9th layer, the tenth layer and eleventh floor are located at minus two layers and minus between three layers, the Floor 12,
13rd layer and the 14th layer is located at minus three layers and minus between four layers, multiple flowing water ranges correspond to after each unit layering, including flow
The 12nd range of water, the 13rd range of flowing water, the 14th range of flowing water, the 15th range of flowing water and the 16th range of flowing water;
The minus two layers of construction of bottom plates of i3, first unit is completed, and intensity carries out the 9th layer of soil by the first soil outlet up to after 90%
Side is excavated, and after bracket groove is excavated in completion the 12nd range of flowing water, laterally opens up side, is set up first unit the 6th and is supported;
I4, after the completion of the minus two layers of construction of bottom plates of second unit, continue to dig bracket groove to center mileage to the second soil outlet position
End is set, the first soil outlet is back to and carries out laterally opening up side, the earthwork has bad luck to the second soil outlet handling, and sets up second unit in time
6th support, the materials such as bracing members are hung in by the second soil outlet, are installed, and are carrying out the 9th layer of the 13rd model of earthwork flowing water
When enclosing excavation, the tenth layer of the 13rd range earth excavation of earthwork flowing water should be carried out simultaneously;
I5, after the completion of the minus two layers of construction of bottom plates of third unit, continue to excavate bracket groove to center mileage to third soil outlet
Terminate, is back to the second soil outlet and carries out laterally opening up side, the earthwork has bad luck to third soil outlet handling, and bracing members are by third soil outlet
It hangs in and is installed, when carrying out the 14th range of the 9th laminar flow of water excavation, while carrying out the 14th range of the tenth laminar flow of water soil
It excavates side;
I6, after the completion of the 15th range of eleventh floor flowing water and the 16th range earthwork of flowing water are excavated, carry out minus three
Layer first unit construction of bottom plates, carries out lower road earth excavation after reaching 90% intensity;
I7, the tenth layer and the 13rd layer of earthwork can be excavated directly longitudinal divisions since depth of seam division is shallower.
Aforesaid way is taken, soil, lifting, when soil carries out cycle operation, due to construction method and sequence are filled in foundation pit
Effective and reasonable, operating efficiency is higher.
Preferably, in the step b and step c, when the earthwork to every layer of bottom plate lower position carries out lid digging, each
The underplate concrete of unit reaches earth excavation under the laggard andante of design strength, and sequence of excavation is that vertical layering from top to bottom is opened
It digs, longitudinal layered formation step, laterally first digs the intermediate soil body, then dig soil at both sides.
Preferably, when constructing minus two layers of bottom plate and negative Tipple Bottom plate, the construction of concrete floor clay model is carried out, including following
Aspect:
F1, middle stringer, the construction of side wall stock mould;
F2, clay model concrete construction;
F3, assembling reinforcement and casting concrete.
Since rich water soft clay area includes silt clay layer and farinose argillic horizon, bearing capacity of foundation slab is low, in bottom plate
Support has bad luck, sets up the job very difficults such as support when upper construction, takes aforesaid way, is applied by carrying out against making floor clay model
Work improves foundation bearing capacity, keeps concrete surface smooth.
Preferably, when carrying out erection bracing members, bracing members are set up with digging with support, and apply axial prestress, bracing members
Erection should ensure that bracing members are vertical with metope, after holding out against using gad support measure fixation.
Preferably, set up bracing members when specifically includes the following steps:
J1, installation steel binder;
J2, installation bracing members,;
J3, apply prestressing force, and according to axle power monitoring data situation, it is determined whether additional prestressing.
Above-mentioned operation and step are taken, guarantees the stability of deep basal pit, since bracing members set up great timeliness, bracing members
Time, position and the prestressed size of application of erection are directly related to deep basal pit and stablize.Bracing members are set up with digging with support, and are applied
Add axial prestress, so that building enclosure is received reaction of bearing effect in advance, reduce the deformation of building enclosure.The erection of bracing members is answered
Guarantee bracing members it is vertical with metope, after holding out against using gad support measure fixation, prevent bracing members because deformation of wall with
Construction is collided and is fallen off.
Preferably, when carrying out side wall construction, following multiple steps are taken:
H1, waterproof construction is carried out to twice construction joint on plate and under plate respectively;
H2, cleaning Full-face pouring pipe, Grouting Pipe nozzle are placed in except template, and carry out binding and fixing with tied silk;
H3, side wall template is installed;
H4, concreting is carried out using steel truss formwork jumbo;
H5, it vibrates, and uses secondary vibration between new-old concrete joint face and dust inlet.
Preferably, in the step h1, construction joint carries out waterproof construction formula on to plate, using galvanized steel plain sheet waterstop,
And the mode of pre-buried Full-face pouring pipe later period slip casting carries out reinforcement water-proofing treatment, construction joint position is stopped using water-swellable under plate
Glue and Full-face pouring pipe combination carry out waterproof construction.
Preferably, in the step h3, when installing side wall template, template at the top of trolley is adjusted to spacious by closely connected mode
The oblique mould of 30~40cm high is arranged in evolution formula on trolley punching block top, and oblique template top surface is higher by construction joint 10cm.
For pouring concrete after avoiding concrete that from can not filling up side wall and the inverse seam for doing the side wall poured under plate, take above-mentioned
Mode had not only facilitated concrete to enter mould, but also can be sufficient filling with the wall top gap that concrete is generated during making firm by ramming due to slump,
Guarantee that construction joint is closely knit.
Preferably, in step h4, side wall uses high fluidity pea gravel concreten, and top area uses microdilatancy coagulation
Soil.This mode is taken, shrinkage of the microdilatancy compensation later period concrete of concrete in hardening process is utilized.
Compared with prior art, beneficial effects of the present invention:
1, by taking above-mentioned covered back-digging construction method, i.e., bracing members frame is set up during covering and digging, while carrying out bottom
Plate construction and concrete are poured work, and carry out side wall, column and top board construction, solve safety existing in the prior art
Problem, the construction method is fast and effective, constructs especially suitable for rich water soft clay area dell, has biggish popularization and application valence
Value;
2, since rich water soft clay area includes silt clay layer and farinose argillic horizon, bearing capacity of foundation slab is low, the bottom of at
Support has bad luck, sets up the job very difficults such as support when constructing on plate, improves ground against the construction of floor clay model is made by carrying out and holds
Power is carried, keeps concrete surface smooth;
3, by setting up bracing members, guarantee the stability of deep basal pit, since bracing members set up great timeliness, bracing members frame
If time, position and apply prestressed size and be directly related to deep basal pit and stablize, bracing members are set up with digging with support, and are applied
Axial prestress makes building enclosure receive reaction of bearing effect in advance, reduces the deformation of building enclosure, the erection of bracing members should be protected
The measure fixation that bracing members are vertical with metope, support after holding out against using gad is demonstrate,proved, prevent bracing members because of deformation of wall and is applied
Work is collided and is fallen off.
Detailed description of the invention:
Structural schematic diagram when Fig. 1 is lower two layers of construction of bottom plates.
Fig. 2 be negative Tipple Bottom plate construction when structural schematic diagram.
Fig. 3 is structural schematic diagram when setting up support.
Structural schematic diagram when Fig. 4 is lower four layers of side wall and the construction of lower four layers of column.
Fig. 5 is negative the structural schematic diagram of three layers of side wall and minus three layers of column when constructing.
Fig. 6 is negative the structural schematic diagram of two layers of side wall and minus two layers of column when constructing.
Structural schematic diagram when Fig. 7 is negative one layer side wall and the construction of negative one layer column.
Fig. 8 is the structural schematic diagram for removing first of concrete.
Fig. 9 is the structural schematic diagram that lid digs section longitudinal direction excavation in layers machine slope.
Marked in the figure: the first soil outlet of 1-, the second soil outlet of 2-, 3- third soil outlet, the 12nd range of 4- flowing water, 5- stream
The 13rd range of water, the 14th range of 6- flowing water, the 15th range of 7- flowing water, the 16th range of 8- flowing water, minus two layers of 9-, 11-
9th layer, the tenth layer of 12-, 13- eleventh floor, minus three layers of 14-, the minus two layers of bottom plate of 15-, the negative Tipple Bottom plate of 16-, 17- bottom plate,
The minus four layers of side wall of 18-, the minus four layers of column of 19-, the minus three layers of side wall of 20-, the minus three layers of column of 21-, the minus two layers of side wall of 22-, 23- minus two
Layer column, 24- negative one layer bottom plate, 25- negative one layer side wall, 26- negative one layer bottom plate, 27- top plate, first of concrete support of 28-, 29-
13rd layer, x- first unit, y- second unit, z- third unit, t- Unit the 4th.
Specific embodiment
Below with reference to test example and specific embodiment, the present invention is described in further detail.But this should not be understood
It is all that this is belonged to based on the technology that the content of present invention is realized for the scope of the above subject matter of the present invention is limited to the following embodiments
The range of invention.
Embodiment 1
Rich water soft clay area deep basal pit covered back-digging construction method, sets deep basal pit as four-layer structure, wherein negative one layer and
Minus two layers use open-cut, and minus three layers and minus four layers are lid excavation construction, and ground is provided with the support of the 1st concrete, on ground and negative
Be disposed between one layer the 2nd support and the 3rd support, negative one layer and it is two layers minus between be disposed with the 4th support
With the 5th support, covered back-digging construction includes following multiple steps:
A, as shown in Figure 1, when excavation of foundation pit to minus two layers of position, using clay model, it is poured 15 concrete of minus two layers of bottom plate, and
Reserved side wall construction joint;
B, as shown in Fig. 2, after minus two layers of bottom plate 15 reaches design strength requirement, lid digs 15 lower position of minus two layers of bottom plate
The earthwork, excavate to setting Support Position when set up the 6th support, be excavated to negative 16 position of Tipple Bottom plate, and be poured minus three layers
16 concrete of bottom plate;
C, as shown in figure 3, after negative Tipple Bottom plate 16 reaches design strength requirement, lid digs negative 16 lower position of Tipple Bottom plate
The earthwork, excavate to setting Support Position when set up the 7th support, be excavated to 17 position of bottom plate, and 17 concrete of bottom board;
D, as shown in figure 4, after 17 intensity of bottom plate reaches design strength requirement, the 7th support is removed, minus four layers of side wall of constructing
18 and minus four layers of column 19;
E, as shown in figure 5, after 18 intensity of minus four layers of side wall reaches design requirement, the 6th support is removed, and construct minus three layers
Side wall 20, minus three layers of column 21;
F, as shown in fig. 6, after minus three layers of side wall intensity reaches design requirement, the 4th and the 5th support is removed, construction is negative
Two layers of side wall 22, minus two layers of column 23 and negative one layer bottom plate 24;
G, as shown in fig. 7, after minus two layers of side wall 22,24 intensity of negative one layer bottom plate up to after design requirement, removing the 2nd and the
3 supports, construction negative one layer side wall 25, negative one layer column 26 and top plate 27;
H, as shown in figure 8, after after negative one layer side wall 25,27 intensity of top plate reach design requirement, first of concrete branch is removed
Support 28.
Aforesaid way is taken, by taking above-mentioned covered back-digging construction method, i.e. erection bracing members frame during covering digging,
Construction of bottom plates and concrete casting work are carried out simultaneously, and carries out side wall, column and top board construction, are solved and are deposited in the prior art
Safety issue, the construction method is fast and effective, especially suitable for rich water soft clay area dell construct.
In covered back-digging work progress, carries out the inverse floor clay model that does and construct.
Minus two layers of bottom plate, negative Tipple Bottom plate are located at silt clay layer, farinose argillic horizon, and bearing capacity of foundation slab is low, minimum
Only 65KPa, though take high-pressure rotary jet grouting pile to be reinforced in design, since reinforcement depth is deeper, most as deep as arrive 26.7m, and
For the weak reinforcing of 3m stripping, foundation bearing capacity is not still high.If meeting the rainy day, excavator walks back and forth and is supported down in addition
Fortune is set up, and substrate soil is even more a piece of miriness, and personnel's walking is all very painstaking.Therefore consider that one layer of bamboo plate+20cmC20 element is mixed
Solidifying soil+separation layer (PVC board or epoxy glass fabric are laminated insulation board) is used as clay model layer.Construction content include:
(1) stringer, the construction of side wall stock mould in
Minus two layers, it is three layers minus in stringer and abutment wall use the brick stock mould at 24cm thickness, the cement sand plaster of 5cm.For
Guarantee the line style and structure size of middle stringer after demoulding, stock mould must be longitudinal straight, and vertical vertical, headroom size, which has to comply with, to be set
Meter requires.
(2) clay model concrete construction
Clay model concrete is the C20 concrete of 20cm, and top of concrete absolute altitude improves 2cm than structural slab bottom absolute altitude, as
The anticipated settlement of top board structure.To guarantee that concrete surface is smooth, no concave-convex injustice phenomenon, each unit clay model concrete is pressed
Lateral framing construction carries out absolute altitude control in the channel steel of every width two sides setting 15cm, after concrete construction, uses aluminium alloy level
It strikes off, press polish plastering is carried out before concrete initial set.For avoid carry out it is inverse make earth excavation under plate when, blinding concrete is in blocks
It falls and mechanical, personnel is damaged.
To guarantee that clay model smoothly demoulds, separation layer (PVC board or epoxy glass fabric lamination insulation are set on concrete cushion
Plate).
(3) reinforcing bar binding and concreting
Reinforcing bar former material steel bar meter field on foundation pit processes, and semi-finished product hang in foundation pit, this engineering steel using truck crane
Muscle connection is using two kinds of forms of the thread rolling bar connection and welding.
Because inwall, frame column lid are dug along doing, in the binding of plate (beam) reinforcing bar, it is necessary to by the pre-buried upper and lower level of design requirement
Chemise and frame column reinforcing bar connector, when embedded ribs are installed, main reinforcement exposed length should be lower than oblique construction joint lowest part under plate
1.5m, reserved steel bar length is the above 1.5m at plate or back on plate, connecing when column of constructing after guarantee is connected with side wall main reinforcement
Head is staggered length.Plate lower contact, which is taken, need to carry out effective protection to steel bar head when mechanical connection, prevent from not carrying out after excavating
Effectively connection.
Earthwork construction the following steps are included:
(1) soil outlet is arranged
Consider effective use this engineering structure reserving hole, along foundation pit direction be staggered 10 be unearthed, feed openings.
(2) device configuration
Two 10T gantry cranes and a 50T crawler type grab bucket are configured, crawler type grab bucket in shield Jing Chu for being unearthed and in advance
It is unearthed when staying soil outlet by ground-connecting-wall side;Gantry crane is carried out unearthed using the stair hole reserved on floor.Grab bucket is equipped with two
PC120 digging machine, every gantry crane are equipped with two PC120 digging machines.
(3) earth excavation
Every unit is inverse reach as board concrete design strength 90% after, the earthwork is according to " vertical layered, Zong Xiangfen under plate
The principle of section, intermediate kerve, two sides extension, pretensioned girder ", vertically stage excavation, longitudinal layered formation step are horizontal from top to bottom
The soil body among first digging, then dig soil at both sides.
The every layer of earthwork of each step is excavated by the sequence of " first extending after intermediate grooving to two sides ", i.e., from the east head to
The excavated surface of western end well longitudinally draws slope to excavate bracket groove along foundation pit, and middle groove width first has to meet excavator revolution spoir
It is required that while guaranteeing to stay soil at both sides again as far as possible more.Bracket groove is excavated by 5m, two sides earthwork balance, symmetrical progress
It excavates.Two sides slope ratio of slope 1:2.5.After intermediate kerve is excavated to the distance of 3~4 bracing members, spread from centre to both sides
It digs, the excavation of soil at both sides should be balanced, symmetrically be carried out.
As shown in figure 9, in the deep basal pit covered back-digging construction method of rich water soft clay area earthwork construction specific steps are as follows:
I1, foundation pit is divided into four units, including first unit x, second unit y, third unit z along foundation pit length direction
With the 4th unit t, and each unit be arranged soil outlet, be included in first unit x be arranged the first soil outlet 1, in second unit y
Second soil outlet 2 is set, third soil outlet 3 is set in third unit z, and configure crawler type grabbing arrangement, the third is unearthed
Mouth 3 extends to the 4th unit t from third unit z;
I2, carry out longitudinal layered excavation to foundation pit, including the 9th layer 11, the tenth layer 12, eleventh floor 13, Floor 12,
13rd layer and the 14th layer (not identifying in figure), described 9th layer 11, the tenth layer 12 and eleventh floor 13 are located at minus two layer 9
With minus three layers between 14, the Floor 12, the 13rd layer and the 14th layer are located at minus three layer 14 and minus between four layers, each unit
Multiple flowing water ranges, including the 12nd range 4 of flowing water, the 13rd range 5 of flowing water, the 14th range 6 of flowing water, stream are corresponded to after layering
The 15th range 7 of water and the 16th range 8 of flowing water;
The minus two layers of construction of bottom plates of i3, first unit x is completed, and intensity carries out the 9th layer 11 by the first soil outlet 1 up to after 90%
Earth excavation is completed laterally to open up side, set up bracing members, be first unit the 6th after bracket groove is excavated in the 12nd range 4 of flowing water
Support;
I4, after the completion of minus two layer of 9 construction of bottom plates of second unit y, continue to dig bracket groove to center mileage to the second soil outlet 2
Position terminates, and is back to the first soil outlet 1 and carries out laterally opening up side, the earthwork has bad luck to 2 handling of the second soil outlet, and sets up steel branch in time
Support, the materials such as bracing members are hung in by the second soil outlet 2, are installed, and are opened carrying out the 9th layer of 11 cubic metres of earth of the 13rd range 5 of flowing water
When digging, the tenth layer of 12 cubic metres of earth of 5 earth excavation of the 13rd range of flowing water should be carried out simultaneously;
I5, after the completion of minus two layer of 9 construction of bottom plates of third unit z, continue to center mileage excavate bracket groove to third be unearthed
Mouth 3 terminates, and is back to the second soil outlet 2 and carries out laterally opening up side, the earthwork has bad luck to 3 handling of third soil outlet, and bracing members are by third
Soil outlet 3, which is hung in, to be installed, and when carrying out the 9th layer of the 14th range 6 of 11 flowing water excavation, while carrying out the tenth layer of 12 flowing water
14th range, 6 earth excavation;
I6, after the completion of 8 cubic metres of earth of the 15th range 7 of 13 flowing water of eleventh floor and the 16th range of flowing water are excavated, carry out
Minus three layer of 14 first unit a construction of bottom plates carries out lower road earth excavation after reaching 90% intensity;
I7, the tenth layer 12, the 13rd layers 29 cubic metres of earth due to depth of seam division it is shallower can directly longitudinal divisions excavate.
Above-mentioned steps and method are taken, the observation of part on the spot is dug to lid, soil is filled in foundation pit, lifting is native, to again
Foundation pit is arrived down, since construction method and sequence are effective and reasonable, operating efficiency is higher, completes this about 8 minutes used time of circulation and (rises
Height 24m~42m drops), 16 hours daily working times, amount of being unearthed daily about 150m3 or so completes one using crawler type grab bucket
It a circulation time about 5 minutes, works daily the identical time, for amount of being unearthed daily about in 260m3 or so, efficiency is much higher than gantry
It when hanging, therefore being related to lid excavation construction, pays the utmost attention to carry out using grab bucket unearthed, needs on floor end bay every certain reserved
Soil outlet.
Embodiment 2
The present embodiment is applied to bracing members and sets up, in demolishing process.
Bracing members, which are set up, excavates the twice critical process that be deep foundation pit construction inseparable, bracing members erection with pit earthwork
Great timeliness, time, position and the prestressed size of application that bracing members are set up are directly related to deep basal pit and stablize.Bracing members
It sets up with digging with support, and applies axial prestress, so that building enclosure is received reaction of bearing effect in advance, reduce the change of building enclosure
Shape.The erection of bracing members should ensure that bracing members are vertical with metope.Using the measure fixation of gad support after holding out against, steel is prevented
Support falls off because of deformation of wall and construction collision.Set up bracing members when specifically includes the following steps:
J1, installation steel binder dig out the pre-buried steel on diaphram wall after soil layer is excavated to support erection design position
Plate welds pallet, installs steel binder;
J2, installation bracing members, bracing members are outside foundation pit according to the width of foundation pit, the length of ground-connecting-wall to steel binder, steel system
Length between beam has spelled tube coupling.Bracing members tube coupling is hung with crane into foundation pit by soil outlet first, it then will by digging machine
Bracing members are transported to installation site.Fixing end is first set up, bracing members are lifted by two digging machines, bracing members one end is held on
On the welded angle iron of pre-embedded steel slab, the other end is shelved on steel binder.Continue to set up the second section, be lifted still through digging machine, it will
Second section one end is connect with first segment by high-strength bolt, and the other end is shelved on another steel binder.Finally set up fixing end
Bracing members are obtained, first pull out segmented head telescopable portion, third section one end and the second section are first passed through high-strength bolt by digging machine lifting
The other end is stably placed on preparatory mounted triangular steel plate by Lian Hao.Pre-embedded steel slab is withstood into movable head pull-out;
J3, prestress application is carried out, and according to axle power monitoring data situation, it is determined whether additional prestressing, it is hydraulic by 2
Jack (according to brace pre axial force size 300T, 500T) is played with digging machine is put into segmented head press position, and pays attention to keeping very heavy
It walks unanimously top row.Connect oil pipe after can turn on pump apply prestressing force, prestress application in place after, in segmented head wedge slot gad plug
Tightly, then jack is unclamped in oil return, unlocks hoisting wirerope, completes the installation of this root support.It should be taken into account when construction prestressing force
Stress loss when operation, construction prestress value should be than designing axle power increase about 10%, and makes a record.
After support applies prestressing force, the anchor ear reinforcing bar of " u "-shaped is close to bracing members, and be securely welded on steel binder
On, two pieces of bolts are filled in the gap of support Yu steel binder, prevent bracing members from being moved left and right by external force.
Axial force of the supports is added with based on axle power monitoring data, supplemented by manual inspection.Axle power monitoring is measurement axle power variation,
If axle power value reduces, it should be added with prestressing force in time.Manual inspection be check support segmented head gag, depending on its loosening whether determine be
It is no to be added with.
Embodiment 3
The present embodiment is constructed applied to side wall, when carrying out side wall construction, comprising the following steps:
H1, waterproof construction is carried out to twice construction joint on plate and under plate respectively;
H2, cleaning Full-face pouring pipe, Grouting Pipe nozzle are placed in except template, and carry out binding and fixing with tied silk;
H3, side wall template is installed;
H4, concreting is carried out using steel truss formwork jumbo;
H5, it vibrates, and uses secondary vibration between new-old concrete joint face and dust inlet.
Concrete operations are as follows:
(1) waterproof construction
According to covered back-digging technological characteristics of construction, ground-connecting-wall is overlapping wall, and there are plate in every layer of side wall and bottom plate, middle plate joint
Twice construction joint under upper, plate, it is therefore necessary to attach great importance to the waterproof quality of construction joint.
Ground-connecting-wall and liner wall construction junction position carry out brushing cement based penetration crystallization type water proofing paint after dabbing processing,
The anti-permeability performance that water reverse osmosis effect improves concrete is met using it.Construction joint position uses galvanized steel plain sheet waterstop on plate,
And the mode of pre-buried Full-face pouring pipe later period slip casting carries out reinforcement water-proofing treatment.Construction joint position is stopped using water-swellable under plate
Glue and Full-face pouring pipe combination carry out waterproof construction, and water-swellable water-stop glue is pasted onto construction seam surface after squeezing out,
Cross dimensions after curing molding is (8-10) mm × (18-20) mm.Galvanized steel plain sheet sealing bandwidth in construction joint position on plate
For 300mm, thickness 4mm, galvanized layer thickness is greater than 30 microns, and construction joint should be located at steel plate middle when steel plate is installed, and connector is adopted
It is docked with welding, it is desirable that steel plate axis is overlapped, and is docked secured, closely knit, waterproof.
Before side wall reinforcement construction, first to construction joint carries out dabbing processing on plate, under plate, it is floating to cut concrete surface
Slurry.Dress watch is carried out to steel plate water stopper pre-buried on plate, guarantees that the height that waterstop exposes is the 1/2 of waterstop height,
Part concrete is dug out to the inadequate position of proud exposure, guarantees the proud exposure of steel plate water stopper, to guarantee construction construction
The position of seam substantially in the half height and position of waterstop, guarantees the effect of sealing.To on the plate cut, concrete laitance under plate
It must clean out, construction joint is rinsed with giant, guarantee construction joint position without residue.
(2) concreting is carried out using steel truss formwork jumbo
The advantages of mobile motor driven walking type steel truss template abutment wall trolley of producer's production: formwork rigidity is big, anti-
Deformability is strong, spells assembly and disassembly without repetition, is mobile in place fast, and short construction period (3~4 days one cycles), every mould pours
Length 12m.After reaching certain intensity after side wall concrete pours, the adjustable bolt of support shuttering rod piece, template are unclamped
After face is entirely detached from concrete surface, start two motors on trolley, driving trolley traveling in orbit to next construction cell
It constructs.
(3) concrete construction
Full-face pouring pipe is cleared up before casting concrete, and Grouting Pipe nozzle is placed in except template, and is carried out with tied silk
Binding and fixing avoid pouring Grouting Pipe nozzle inside side wall in casting process.When installing side wall template, to avoid coagulation
Soil can not fill up pouring concrete and the inverse seam for doing the side wall poured under plate after side wall, by template at the top of trolley by closely connected mode tune
Whole is mode of opening wide, and the oblique mould of 30~40cm high is arranged on trolley punching block top, oblique template top surface is higher by construction joint 10cm.This
Sample had not only facilitated concrete to enter mould, but also can be sufficient filling with the wall top gap that concrete is generated during making firm by ramming due to slump, protected
It is closely knit to demonstrate,prove construction joint.Side wall uses high fluidity pea gravel concreten, and top area utilizes concrete using slightly expanded concrete
Microdilatancy compensates shrinkage of the later period concrete in hardening process.In addition to routinely vibrating, in new-old concrete joint face under
Secondary vibration is used between grey mouth.It cuts for convenience, because the side wall wedge shape coagulation local product for being tiltedly molded as more pouring is at the beginning of concrete
It cuts, and is modified immediately after solidifying.