Big width foundation pit supporting construction in the case of artesian water
Technical field
The present invention relates to big width foundation pit supporting construction is it is adaptable to the realm of building construction in the case of a kind of artesian water.
Background technology
If foundation ditch width is larger, support beam axle power can be very big, and some support beams not can be destroyed due to load.Separately
Outward, the shearing of support beam adjacent edges is very big, and engineering practice central branch supports the concrete of beam adjacent edges because of shearing strength not
Enough destroyed.Support beam span very big in the case of foundation ditch width is larger, middle part moment of flexure can be very big, some ergonomic support
Can curved crush bad in the middle part of beam.When deep basal pit bottom is with the presence of artesian aquifer, excavation pit can reduce water-bearing layer upper confining bed
Thickness, when impermeable layer thickness reduces to a certain extent, the head pressure energy capping of artesian water or the foundation ditch foundation soil that destroys by rush of water, give
Construction brings very big difficulty.
Content of the invention
The technical problem to be solved is to provide big width foundation pit supporting construction in the case of a kind of artesian water, the party
The method easy stress destruction of support beam, the asking of pressure-bearing water destruct bottom of foundation ditch foundation soil in solving big width foundation pit support construction
Topic.
Outside support pile in the technical scheme providing for this present invention, water-stop curtain is set, if place has artesian water
Layer, water-stop curtain depth is 25~30m, and using three axle cement mixing pile water stopping curtains, cement mixing pile adopts three rows.If not yet
There is artesian aquifer, water-stop curtain depth is 15~20m, and using two axle cement mixing pile water stopping curtains, cement mixing pile adopts two
Row.
For the protuberance that prevents from being broken ground inside support pile, broken ground inside support pile and reinforced using water under high pressure mud,
Reinforcing position is 1~1.2 times of the following excavation of foundation pit depth of foundation ditch bottom absolute altitude, and reinforcing width is 1~1.5m.
The present invention, according to the feature of big width foundation ditch, using engineering pile as the strong point of support beam, makes support beam become even
Continuous beam, thus reduce the span of support beam.Electric heat prestressing is carried out to presstressed reinforcing steel, makes jointly holding of deformed bar and concrete
Power effect more preferably, can bear bigger bending moment and axle power.Deformed bar is turned up near supporting-point, can effectively suppress to cut
Cut through bad generation.
Support pile top arranges Guan Liang, and Guan Liang concrete strength is more than or equal to C30, and Guan Liang height is 700~1000mm,
Support beam and engineering pile connection, engineering pile reinforcing bar is bent into right angle after stretching into support beam and is anchored, and anchorage length is 40 times of works
Journey stake bar diameter, support pile becomes two hold-down supports of support beam, and engineering pile becomes the bearing support of support beam, supports
Beam becomes beam structure, and this just alleviates the moment of flexure that support beam is born significantly.Support beam adopts deformed bar, prestressing force
Reinforcing bar adopts broken line tensioning, and broken line point is arranged on 2/3 position of 1/3 and single span of single span in beam structure, due to continuous
In girder construction, between supporting-point and 1/3 point of single span, position is based on hogging moment load, and the present invention agrees with this feature and propping up
Hold a little and 1/3 point of single span between reinforcing bar adopt diagonally disposed, so that reinforcing steel bar bear efficiency is given full play to.Anchoring piece is by deformed bar
It is fixed on billet.
Oblique section of middle part setting ejection device of deformed bar, controls oblique section of angle by an ejection device height.For subtracting
Little frictional resistance, an ejection device top surface does in the arc-shaped, the thick poly- trifluoro-ethylene plate of 1 5mm of stickup in the cambered surface of an ejection device, with
Reduce the frictional resistance propping up between ejection device and deformed bar.
If place has artesian aquifer, arrange vent in the range of artesian water, arrange one along the every 10~15m of foundation ditch
Vent, a diameter of 400~600mm of vent, vent includes marine riser, filter pipe, precipitation tube, marine riser, filter pipe, heavy
Shallow lake pipe diameter is identical, a diameter of 200~400mm, and diameter is adjusted according to artesian head, is less than or equal to for artesian head
During 3m, a diameter of 200mm, when artesian head is more than to 3m and is less equal than 8m, a diameter of 250mm, for artesian head
More than 8m and less equal than 12m when, a diameter of 300mm, for artesian head be more than 12m and less equal than 15m when, diameter
For 350mm, when being more than 15m for artesian head, a diameter of 400mm.Marine riser, filter pipe, precipitation tube are all using pipe of concrete
Or steel pipe, pipe of concrete wall thickness is 30mm, and thickness of steel pipe is 6mm, arranges clay outside marine riser, water proof bottom of the tube 0.5~
Outside marine riser in the range of 0.8m, setting ball sealer is used for water proof, is filter pipe below marine riser, and filter pipe is arranged on artesian water
Position, drainage tube wall is dug aperture to intake, hole diameter is 3~5mm, percent opening is 15~20%, drainage pipe outer wall
Parcel filter screen, outside filter screen, setting aggregate chips is used for drainage, a diameter of 2~4mm of aggregate chips, is precipitation tube below filter pipe, precipitation tube
Length is 1~1.2m.Ball sealer adopts rubber to make, and inflates ball sealer, put into decompression in the hole, it is to float over decompression before placing
On the water surface of in the hole.Then start to put clay, clay ball sealer can be depressed into water proof bottom of the tube it is ensured that drainage layer water not to
Upper infiltration.
Construction procedure includes:
(1) construction work stake
The Construction of Engineering Pile shelving support beam to supporting bottom elevation, mark by Other Engineering pile driving construction to basement bottom board bottom
High.
(2) construction supporting stake
Support pile adopts large diameter bored pile, and cast-in-situ bored pile deposit control is within 15cm.
(3) construction water-stop curtain
(4) construction soil cement stabilization zone
(5) pour Guan Liang
(6) Construction Support beam
Install support beam deformed bar, setting ejection device, carry out being energized for the first time before support beam concreting
Heating, electrified regulation 5min, sets up primary stress, then by anchoring piece, deformed bar is fixed on billet, anchoring piece
Fixation finishes after-pouring concrete, carries out second electrified regulation in concrete initial set, electrified regulation 10min, in concrete
Carry out third time electrified regulation after pouring 12 hours, set up prestressing force, with anchoring piece, deformed bar is fixed on billet.
(7) cut the earth
Earth excavation adopts benzvalene form stage excavation, and earthwork lift height is 40~50mm, foundation ditch 2.5~3.5m scope nearby
The interior earthwork is first retained, and slows down support pile with the drag making full use of periphery back-pressure soil and deforms into hole.In the middle part of excavating first
Region, then used in supporting lower subregion, symmetrical shoveling, is finally transferred to the earthwork in the range of 2.5~3.5m near foundation ditch, by digging machine
It is loaded into dump truck and transport foundation ditch.
Brief description
Fig. 1 is foundation pit supporting construction schematic diagram, and Fig. 2 is vent elevational schematic view, and Fig. 3 is vent section 1 schematic diagram,
Fig. 4 is vent section 2 schematic diagram.
In each accompanying drawing:1st, support pile, 2, water-stop curtain, 3, soil cement stabilization zone, 4, Guan Liang, 5, engineering pile, 6, support beam,
7th, deformed bar, 8, ejection device, 9, billet, 10, anchoring piece, 11, marine riser, 12, filter pipe, 13, precipitation tube, 14,
Clay, 15, ball sealer, 16, filter screen, 17, aggregate chips.
Specific embodiment
11 layers on the ground of certain engineering, 1 layer of underground, overall floorage 75400m2, wherein basement construction area 6100m, foundation ditch
Width is larger, reaches 64m, and foundation depth is 5.8m, and using frame shear wall structure, it is stagnant that place groundwater type includes upper strata
Water and porous confined groundwater.The main preservation of perched water, in artificial miscellaneous fill layer, mainly accepts Atmospheric precipitation and earth's surface aproll
Infiltration supply, no unifies table, and the water yield is in close relations with season, periphery Escape condition.Artesian water and surface water and region
Pressure-bearing aqueous systems close relation, the water yield is enriched, and artesian head is 5~7m.
As illustrated, big width foundation pit supporting construction includes setting outside support pile 1 in the case of the artesian water of present invention offer
Put water-stop curtain 2, water-stop curtain 2 depth is 28m, and using three axle cement mixing pile water stopping curtains 2, cement mixing pile adopts three
Row.Broken ground inside support pile 1 and reinforced using water under high pressure mud, reinforcement depth be excavation of foundation pit depth 1 again to 2 times, plus
Gu width is 1~1.5m.Using engineering pile 5 as the strong point of support beam 6, support beam 6 is made to become continuous beam.Presstressed reinforcing steel is entered
Row electric heat prestressing.
Support pile 1 top arranges Guan Liang 4, and Guan Liang 4 concrete strength is C35, and Guan Liang 4 height is 900mm, support beam 6 He
Engineering pile 5 connects, and engineering pile 5 reinforcing bar is bent into right angle after stretching into support beam 6 and is anchored, and anchorage length is 40 times of engineering piles 5
Bar diameter, support pile 1 becomes two hold-down supports of support beam 6, and engineering pile 5 becomes the bearing support of support beam 6, supports
Beam 6 becomes beam structure.Support beam 6 adopts deformed bar 7, and deformed bar 7 adopts broken line tensioning, and broken line point is arranged on
2/3 position of 1/3 and single span of single span in beam structure.Deformed bar 7 is fixed on billet 9 by anchoring piece 10.
Oblique section of middle part setting ejection device 8 of deformed bar 7, controls oblique section of angle by ejection device 8 height.?
Ejection device 8 top surface does in the arc-shaped, the thick poly- trifluoro-ethylene plate of 1 5mm of stickup in the cambered surface of an ejection device 8, is propped up with reducing
Frictional resistance between ejection device 8 and deformed bar 7.
There is artesian aquifer in place, arrange vent, arrange a vent along the every 12m of foundation ditch in the range of artesian water,
The a diameter of 450mm of vent, vent includes marine riser 11, filter pipe 12, precipitation tube 13, marine riser 11, filter pipe 12, precipitation
Pipe 13 diameter is identical, a diameter of 250mm.Marine riser 11, filter pipe 12, precipitation tube 13 are all using pipe of concrete, concrete tube wall
Thick is 30mm, marine riser 11 outside setting clay 14, marine riser 11 outside setting ball sealer in the range of marine riser 11 bottom 0.6m
15 are used for water proof, and marine riser 11 is filter pipe 12 below, and filter pipe 12 is arranged on artesian water position, filter pipe 12 tube wall is dug
To intake, hole diameter is 4mm to aperture, and percent opening is 18%, and filter pipe 12 outer wall wraps up filter screen 16, filter screen 16 outside setting stone
Bits 17 are used for drainage, a diameter of 2~4mm of aggregate chips 17, and filter pipe 12 is precipitation tube 13 below, and precipitation tube 13 length is 1.1m.Close
Blocking 15 adopts rubber to make, and inflates ball sealer 15, put into decompression in the hole before placing, and it is the water surface floating over decompression in the hole
On.Then start to put clay 14, clay 14 ball sealer 15 can be depressed into marine riser 11 bottom it is ensured that drainage layer water not upwards
Infiltration.
Construction procedure includes:
(1) construction work stake 5
The engineering pile 5 shelving support beam 6 is constructed to support beam 6 bottom absolute altitude, and Other Engineering stake 5 is constructed to basement bottom board bottom
Absolute altitude.
(2) construction supporting stake 1
Support pile 1 adopts large diameter bored pile, and cast-in-situ bored pile deposit control is within 15cm.
(3) construction water-stop curtain 2
(4) construction soil cement stabilization zone 3
(5) pour Guan Liang 4
(6) Construction Support beam 6
Install support beam 6 deformed bar 7, setting ejection device 8, carry out before support beam 6 concreting for the first time
Electrified regulation, electrified regulation 5min, sets up primary stress, then by anchoring piece 10, deformed bar 7 is fixed on billet
9, anchoring piece 10 fixation finishes after-pouring concrete, carries out second electrified regulation, electrified regulation in concrete initial set
10min, carries out third time electrified regulation after 12 hours of concreting, sets up prestressing force, with anchoring piece 10 by prestressing force
Reinforcing bar 7 is fixed on billet 9.
(7) cut the earth
Earth excavation adopts benzvalene form stage excavation, and earthwork lift height is 40~50mm, foundation ditch 2.5~3.5m scope nearby
The interior earthwork is first retained, and slows down support pile 1 with the drag making full use of periphery back-pressure soil and deforms into hole.In the middle part of excavating first
Region, then used in supporting lower subregion, symmetrical shoveling, is finally transferred to the earthwork in the range of 2.5~3.5m near foundation ditch, by digging machine
It is loaded into dump truck and transport foundation ditch.
In the excavation and support processes of whole foundation ditch, uninterrupted observation is carried out to 18 observation stations of prior setting, its
The maximal displacement amount of middle measuring point is 6mm, and foundation ditch does not occur gushing native phenomenon in work progress all the time, meets deep pit monitor stable
Needs, also ensure that the safety of surrounding building and urban operating mechanism simultaneously.