Soft clay area basement supporting and protection structure
Technical field
The present invention relates to a kind of supporting and protection structure, particularly soft clay area basement supporting and protection structure.
Background technology
Along with the propelled at high velocity that Chinese Urbanization's is built, there has been great development in basement engineering field.The factors such as foundation depth and scale strengthen, surrounding enviroment are tending towards complexity, the construction period is more urgent bring opportunity to the renewal of basement support technology, also bring engineering safety problem simultaneously.Particularly soft clay area, special geological conditions makes these engineering safety problems more complicated.How can ensure basement construction safety can reduce costs again be engineers and technicians will faced by problem.
Summary of the invention
The present invention is to provide a kind of soft clay area basement supporting and protection structure, solves the problem of prior art.
For this reason, basement supporting arranges twice and puts slope, first puts slope and second puts top, slope laying mixed concrete board, and concrete slab thickness is 12mm, and it is 35 ° ~ 45 ° that first puts the slope gradient, it is 1.5m ~ 2m that first puts slope height, first is put slope outboard end and is arranged water-stop curtain, and water-stop curtain adopts double deep-mixed pile, and deep-mixed pile lap length is 200mm, the deep-mixed pile degree of depth is 15m, and cement mixing content is 15%.First is put slope angle position, slope and is arranged channel-section steel gear weir, channel-section steel gear weir thickness is 12mm, channel-section steel gear height of weir degree is 1.2 ~ 1.3 times that first puts slope height, channel-section steel gear weir arranged outside concrete tube, the internal diameter of concrete tube is 400 ~ 500mm, paving geotextiles inside concrete tube, in the middle of concrete tube, gutter is set, gutter diameter is 50mm, bottom gutter, gauze wire cloth is set, geotextiles is wrapped up below gauze wire cloth, filling cobble in space between gutter and concrete tube, it is 30 ° ~ 40 ° that second puts the slope gradient, it is 1.5 ~ 2m that second puts slope height, second is put in the middle of the horizontal segment of slope and is arranged negative pressure well, second is put slope slope angle and is arranged gutter, depth of drainage ditch is 30 ~ 35mm, slope protection pile adopts bored pile, bored pile diameter is 800 ~ 1000mm, the slope protection pile degree of depth is the basement degree of depth 1.5 ~ 2.5 times, slope protection pile top arranges capping beam, first anchor pole is fixed on capping beam by ground tackle, the anchor pole gradient is 25 ° ~ 30 °, free lengthes of bolt is 6m, anchorage length is 10m, capping beam buries pre-embedded steel slab underground, pre-embedded steel slab thickness is 20mm, upper diagonal brace welds with pre-embedded steel slab, upper diagonal brace level interval is 5 ~ 7m, upper diagonal brace adopts seamless steel pipe, upper diagonal brace is by being fixed on above angle steel after jack tension, angle steel and the Plate Welding being embedded in concrete buttress.Capping beam arranges and hangs muscle, arranges middle girder inside slope protection pile, and middle girder is connected with slope protection pile by embedded bar on the one hand, connects on the other hand by hanging muscle with capping beam.Middle girder is bearing in above concrete buttress by lower diagonal brace.Second anchor pole is fixed on middle girder by ground tackle, and the anchor pole gradient is 25 ° ~ 30 °, and free lengthes of bolt is 6m, and anchorage length is 10m.Arrange inside slope protection pile by stabilization zone of breaking ground, stabilization zone of being broken ground adopts rotary churning pile, and stabilization zone width of being broken ground is 1.2 ~ 1.5m, and the degree of depth is 1.1 ~ 1.2 times of basement cutting depths.
Construction sequence comprises:
(1) construction water-stop curtain.
(2) construction slope protection pile.
(3) construction is by stabilization zone of breaking ground.
(4) earth excavation, does first and puts slope, often excavates one section of earthwork and synchronously inserts channel-section steel gear weir.
(5) install concrete tube, centre arranges gutter, filling cobble in space between gutter and concrete tube.After this concreting plate, then discharges water by gutter, dewatering.
(6) negative pressure precipitation.
Negative pressure well adopts separate filter, and separate filter is double-decker.Outer filter device is that tunneling boring is permeable, can guarantee the same with common negative pressure well the water in soil layer to be entered in dewatering well fast; Internal layer strainer is only provided with water inlet in bottom, guarantees that the water and air in soil layer can only enter internal layer strainer in bottom.During precipitation, sealing internal layer strainer well head adopts negative pressure pump to deflate formation negative pressure, make to form head difference outside interior pipe and pipe, simultaneously in internal layer strainer, installing submersible pump draws water and reduces this head difference, and the water between such ectonexine strainer and in soil layer is entered internal layer strainer from internal layer filter bottom water inlet and discharged by submersible pump constantly under differential pressure action.Gas leakage can not be caused under water because internal layer filter bottom water inlet is embedded in all the time.In pump process, common negative pressure well is usually when groundwater table drops to lower than top treatment hole, and in soil layer, air is entered in well by top treatment hole, thus makes vacuum degree in well produce decay, affects negative pressure vacuum effect.And negative pressure well internal layer filter bottom water inlet can remain under water in the technical program, thus the air completely cut off in soil layer enters internal layer strainer by bottom water inlet, and then avoids the vacuum degree decay of internal layer strainer.How groundwater level no matter outside negative pressure drop well declines, as long as internal layer filter bottom water inlet keeps water seal, can remain a larger negative pressure in internal layer strainer.
(7) earth excavation, does second and puts slope, puts concreting plate after slope, arranges gutter and carries out draining.
(8) earth excavation supports to the 3rd road and arranges position.
(9) build capping beam, and bury pre-embedded steel slab underground and hang muscle.
(10) first anchor pole is installed.
Anchor bolt construction improves conventional art by the following technical programs: the sand of the weight such as the low-alkali concrete expansion agent replacement with 14%, two Grouting Pipe are entered at present together what cast anchor, article one, Grouting Pipe is the foraminate pre-buried floral tube of band, and with friction tape, aperture is closed, another Grouting Pipe is pulled out after having carried out a normal pressure grouting.Reach after 5.0MPa intensity until slurry, then carry out fracture grouting by the pre-buried floral tube high pressure being greater than 2.5MPa, make slurries to hole wall surrounding soil diffusion extruding, the corresponding expansion of anchoring body.Use waste cement paper bag by aperture fast sealing after slip casting at once.
(11) earth excavation is to middle girder position, cuts open the surface concrete from slope protection pile, is welded by middle beam main tendon with the main muscle of slope protection pile, welds the main muscle of slope protection pile simultaneously and hangs muscle.
(12) second anchor pole is installed.
(13) the excavation local earthwork is to base plate position, arranges concrete buttress, and concrete buttress periphery reserves earthen platform as back-pressure soil, and it is 40 ° ~ 45 ° that the slope gradient is put in earthen platform.
(14) diagonal brace is installed.Upper diagonal brace upper end is welded with the pre-embedded steel slab being embedded in capping beam, and prestressed stretch-draw is carried out in upper diagonal brace lower end, is fixed on the angle steel connected with concrete buttress after prestressed stretch-draw.Prestressing force pull-up values adjusts in real time according to maximum soil body deep soil movement value.When maximum soil body deep soil movement value is greater than 10mm, prestressing force pull-up values adopts 800kN, when maximum soil body deep soil movement value is more than or equal to 10mm and is greater than 6mm, prestressing force pull-up values adopts 600kN, when maximum soil body deep soil movement value is less than or equal to 6mm, prestressing force pull-up values adopts 400kN.
(15) lower diagonal brace is installed.Upper diagonal brace upper end is welded with the pre-embedded steel slab being embedded in capping beam, and upper diagonal brace lower end is fixed on concrete buttress.
(16) surplus earth is excavated to base plate position, concreting base plate.
(17) concreting sidewall.
(18) lower diagonal brace and upper diagonal brace is removed.Lower diagonal brace and upper diagonal brace adopt the disposable dismounting of autogenous cutting.
Construction cost of the present invention is low, and the construction period is short.
Accompanying drawing explanation
Fig. 1 is soft clay area basement supporting and protection structure schematic diagram.
In each accompanying drawing: 1, water-stop curtain, 2, concrete slab, 3, concrete tube, 4, channel-section steel gear weir, 5, geotextiles, 6, gutter, 7, cobble, 8, negative pressure well, 9, anchor pole, 10, slope protection pile, 11, gutter, 12, capping beam, 13, upper diagonal brace, 14, middle girder, 15, muscle is hung, 16, lower diagonal brace, 17, pre-embedded steel slab, 18, concrete buttress, 19, angle steel, 20, by stabilization zone of breaking ground.
Detailed description of the invention
In the present embodiment, basement supporting arranges twice and puts slope, first puts slope and second puts top, slope laying mixed concrete board 2, concrete slab 2 thickness is 12mm, it is 40 ° that first puts the slope gradient, and it is 1.8m that first puts slope height, and first is put slope outboard end and arranged water-stop curtain 1, water-stop curtain 1 adopts double deep-mixed pile, deep-mixed pile lap length is 200mm, and the deep-mixed pile degree of depth is 15m, and cement mixing content is 15%.First is put slope angle position, slope and is arranged channel-section steel gear weir 4, channel-section steel gear weir 4 thickness is 12mm, channel-section steel gear weir 4 is highly for first puts 1.25 times of slope height, channel-section steel gear weir 4 arranged outside concrete tube 3, the internal diameter of concrete tube 3 is 450mm, paving geotextiles 5 inside concrete tube 3, in the middle of concrete tube 3, gutter 6 is set, gutter 6 diameter is 50mm, bottom gutter 6, gauze wire cloth is set, geotextiles 5 is wrapped up below gauze wire cloth, between gutter 6 and concrete tube 3, cobble 7 is clogged in space, it is 35 ° that second puts the slope gradient, it is 1.8m that second puts slope height, second is put in the middle of the horizontal segment of slope and is arranged negative pressure well 8, second is put slope slope angle and is arranged gutter 11, gutter 11 degree of depth is 30mm, slope protection pile 10 adopts bored pile, bored pile diameter is 900mm, slope protection pile 10 degree of depth is the basement degree of depth 2 times, slope protection pile 10 top arranges capping beam 12, first anchor pole 9 is fixed on capping beam 12 by ground tackle, anchor pole 9 gradient is 25 °, anchor pole 9 drift is 6m, anchorage length is 10m, capping beam 12 buries pre-embedded steel slab 17 underground, pre-embedded steel slab 17 thickness is 20mm, upper diagonal brace 13 welds with pre-embedded steel slab 17, upper diagonal brace 13 level interval is 5 ~ 7m, upper diagonal brace 13 adopts seamless steel pipe, upper diagonal brace 13 is by being fixed on above angle steel 19 after jack tension, angle steel 19 and the Plate Welding being embedded in concrete buttress 18.Capping beam 12 arranges and hangs muscle 15, and arrange middle girder 14 inside slope protection pile 10, middle girder 14 1 aspect is connected with slope protection pile 10 by embedded bar, connects on the other hand by hanging muscle 15 with capping beam 12.Middle girder 14 is bearing in above concrete buttress 18 by lower diagonal brace 16.Second anchor pole 9 is fixed on middle girder 14 by ground tackle, and anchor pole 9 gradient is 25 °, and anchor pole 9 drift is 6m, and anchorage length is 10m.Arrange stabilization zone 20 of being broken ground inside slope protection pile 10, stabilization zone 20 of being broken ground adopts rotary churning pile, and stabilization zone 20 width of being broken ground is 1.3m, and the degree of depth is 7m.
Construction sequence comprises:
(1) construction water-stop curtain 1.
(2) construction slope protection pile 10.
(3) construction is broken ground stabilization zone 20.
(4) earth excavation, does first and puts slope, often excavates one section of earthwork and synchronously inserts channel-section steel gear weir 4.
(5) install concrete tube 3, centre arranges gutter 6, and between gutter 6 and concrete tube 3, cobble 7 is clogged in space.After this concreting plate 2, then discharges water by gutter 6, dewatering.
(6) negative pressure precipitation.
Negative pressure well 8 adopts separate filter, and separate filter is double-decker.Outer filter device is that tunneling boring is permeable, and internal layer strainer is only provided with water inlet in bottom.During precipitation, sealing internal layer strainer well head adopts negative pressure pump to deflate formation negative pressure, make to form head difference outside interior pipe and pipe, simultaneously in internal layer strainer, installing submersible pump draws water and reduces this head difference, and the water between such ectonexine strainer and in soil layer is entered internal layer strainer from internal layer filter bottom water inlet and discharged by submersible pump constantly under differential pressure action.
(7) earth excavation, does second and puts slope, puts concreting plate 2 after slope, arranges gutter 11 and carries out draining.
(8) earth excavation supports to the 3rd road and arranges position.
(9) build capping beam 12, and bury pre-embedded steel slab 17 underground and hang muscle 15.
(10) first anchor pole 9 is installed.
The sand of the weight such as the low-alkali concrete expansion agent replacement with 14%, two Grouting Pipe are entered at present together what cast anchor, article one, Grouting Pipe is the foraminate pre-buried floral tube of band, and is closed by aperture with friction tape, and another Grouting Pipe is pulled out after having carried out a normal pressure grouting.Reach after 5.0MPa intensity until slurry, then carry out fracture grouting by the pre-buried floral tube high pressure being greater than 2.5MPa, make slurries to hole wall surrounding soil diffusion extruding, the corresponding expansion of anchoring body.Use waste cement paper bag by aperture fast sealing after slip casting at once.
(11) earth excavation is to middle girder 14 position, cuts open the surface concrete from slope protection pile 10, is welded by main for middle girder 14 muscle with the main muscle of slope protection pile 10, welds the main muscle of slope protection pile 10 simultaneously and hangs muscle 15.
(12) second anchor pole 9 is installed.
(13) the excavation local earthwork is to base plate position, arranges concrete buttress 18, and concrete buttress 18 periphery reserves earthen platform as back-pressure soil, and it is 40 ° ~ 45 ° that the slope gradient is put in earthen platform.
(14) diagonal brace 13 is installed.Upper diagonal brace 13 upper end is welded with the pre-embedded steel slab 17 being embedded in capping beam 12, and prestressed stretch-draw is carried out in upper diagonal brace 13 lower end, is fixed on the angle steel 19 connected with concrete buttress 18 after prestressed stretch-draw.Prestressing force pull-up values adjusts in real time according to maximum soil body deep soil movement value.When maximum soil body deep soil movement value is greater than 10mm, prestressing force pull-up values adopts 800kN, when maximum soil body deep soil movement value is more than or equal to 10mm and is greater than 6mm, prestressing force pull-up values adopts 600kN, when maximum soil body deep soil movement value is less than or equal to 6mm, prestressing force pull-up values adopts 400kN.
(15) lower diagonal brace 16 is installed.Upper diagonal brace 13 upper end is welded with the pre-embedded steel slab 17 being embedded in capping beam 12, and upper diagonal brace 13 lower end is fixed on concrete buttress 18.
(16) surplus earth is excavated to base plate position, concreting base plate.
(17) concreting sidewall.
(18) lower diagonal brace 16 and upper diagonal brace 13 is removed.Lower diagonal brace 16 and upper diagonal brace 13 adopt the disposable dismounting of autogenous cutting.
From the overall process of basement excavation, maximum soil body deep soil movement is 10mm, and the soil excavation of this engineering is safe and reliable.Meanwhile, the requirement that construction cost is low and the construction period is short is also met.