Cloth bag grouting pile-forming method
Technical field:
The present invention relates to ground processing in the building field, relate in particular to a kind of cloth bag grouting pile-forming method that is applicable to reinforced soft soil ground.
Background technology
Technical scheme that ground is handled and stake type have a variety of, need very high drilling cramp and broader place as agitation pile, CFG stake etc.When the soft or hard soil layer was the alternating layers shape, other conventional ground stabilization means existed reinforcement depth limited, the technological deficiency that hard formation is difficult to penetrate.
Summary of the invention
The objective of the invention is in order to solve the deficiency that the above-mentioned background technology exists, propose the cloth bag grouting pile-forming method and the special slip casting pipe thereof of a kind of controlled investment well and solution settlement stability problem.
For achieving the above object, the present invention adopts following technical scheme: cloth bag grouting pile-forming method is characterized in that this method may further comprise the steps:
1) in soil layer, uses boring machine pile hole;
2) cloth bag is enclosed within outside the Grouting Pipe, with cloth bag with the merogenesis colligation vertically of soft band on Grouting Pipe, cloth bag two ends respectively colligation are tight, the Grouting Pipe lower end closed is provided with injected hole on the Grouting Pipe tube wall;
3) Grouting Pipe that will be with cloth bag is inserted in the stake hole;
4) pursue joint slip casting in cloth bag from bottom to top by Grouting Pipe, after every joint is annotated design pressure, pour down a joint,, form a complete pile body until cloth bag is filled with.
In such scheme, in described step 2, described Grouting Pipe is made up of Grouting Pipe body, tube end locating piece and neck positioning sleeve, described neck positioning sleeve is enclosed within on the Grouting Pipe tube wall, described end locating piece is positioned at Grouting Pipe body bottom, the colligation of cloth bag lower end is on the locating piece of Grouting Pipe end, and cloth bag upper end colligation is on Grouting Pipe neck positioning sleeve; In described step 3, Grouting Pipe neck positioning sleeve is placed the design elevation place of bag pile in the hole, Grouting Pipe end locating piece is placed a bottom, hole.
Seal with plug in described Grouting Pipe body lower end, this plug can be blocked Grouting Pipe neck positioning sleeve.
In such scheme, in described step 2, described Grouting Pipe can also be by the Grouting Pipe body, guide pipe and slip casting rifle head are formed, merogenesis is provided with injected hole vertically on the guide pipe tube wall, described slip casting rifle head comprises the short tube of an external diameter less than above-mentioned guide pipe internal diameter, short tube inserts in the guide pipe, on the tube wall of short tube, be provided with rifle head injected hole, what seal between being provided with guide pipe body and short tube on the short tube tube wall on rifle head injected hole both sides only starches piston, described short tube lower end closed, the upper end is connected with the Grouting Pipe body, cloth bag is enclosed within outside the guide pipe, and merogenesis colligation vertically is on the tube wall between adjacent two injected holes, and tighten respectively on the guide pipe body at the cloth bag two ends; In described step 4, slip casting rifle head pursues joint slip casting in cloth bag from bottom to top by the injected hole of guide pipe body, after every joint is annotated design pressure, promotes slip casting rifle head, pours down a joint, until cloth bag is filled with, forms a complete pile body.
Preferably be with the elastic tape that injected hole can be blocked in the injected hole position of above-mentioned guide pipe.
The present invention utilizes Grouting Pipe slip casting in cloth bag, slurries should adopt the Portland cement slurries, label is not less than PO32.5, also a certain proportion of flyash can be gone into disastrously,, an amount of swell soil can be added during stirring for preventing slurries premature disengagement and precipitation, the key property of slurries should reach: viscosity 30 "~35 ", proportion 1.4~1.5, bleed rate<3%, uniaxial compressive strength>2.4~2.8MPa (be 7 days the length of time).
Grouting pressure is mainly considered factors such as the buried depth, soil body confined pressure of grouting pile, is generally 0.2~0.5Mpa, adopts low pressure when buried depth is shallow, adopts big value when buried depth is big, should strict control grouting pressure in the slip casting process; The slurries injection rate should be according to the control of factors such as expanded diameter and eyelet quantity, size, and the injection rate of general minor diameter, shallow embedding stake is controlled at 10~12L/min, and the injection rate of major diameter, buried stake is controlled at 50~75L/min, must guard against blindly excessive.
Cloth bag is selected φ 300~400mm roll type for use, generally selects unit area 230g/m for use
2, CRB bursting strength 〉=5.5KN, effective aperture O
900.07~0.5mm, tearing strength 〉=0.9KN, coefficient of permeability K=1 * 10
-2~10
-3Cm/s.
The present invention adopts bag pile to reinforce weak soil layer for sleeping in down, well controlled investment and solution settlement stability problem.Because the buffer action of cloth bag is arranged, and cement paste reaches the compacted peripheral soil body by the expansion cloth bag, separates out moisture, form the column pile body of rule, and strength of the mixing pile is higher, controlled.
The present invention has following characteristics:
1, the cement grout cloth bag that expands under pressure, the compacted soil body forms the vertical drainage passage, plays vertical reinforced action, improves the bearing capacity and the composite modulus of foundation soil;
2, grouting pressure and slurries injection rate etc. can be controlled by metering device;
3, pile body length, intensity, stake footpath etc. are controlled, can implement to reinforce in the designated depth scope;
4,, be mainly used in and reinforce homogeneous, alternating layers shape soft foundation as vertical reinforcement; Also can be used as transversal reinforcement, be used for the slope reinforcement of loose ground;
5, look working environment, geologic setting condition, optional majority kind construction equipment pore-forming pile;
6, cloth bag size and correlation technique parameter should be purpose to satisfy grouting pressure and slurries controlled.
Description of drawings
Fig. 1 is embodiment 1 a pile schematic diagram.
Fig. 2 is embodiment 2 pile schematic diagrames.
Fig. 3 is embodiment 2 Grouting Pipe generalized sections.
The specific embodiment
Embodiment 1: referring to Fig. 1, Fig. 1 has shown the forming process of buried bag pile in the alternating layers weak soil.
The method of present embodiment may further comprise the steps:
1) in soil layer, uses boring machine pile hole 5.Boring machine adopts general geology rig, circle round rig or vibration sinking tube machine, can suitably dispose slurry coat method as required.When adopting the rig pore-forming, opening diameter 〉=91mm, general clear water circulation for the stratum, hole that easily collapses, is used mud circulation instead when creeping into.When adopting vibration sinking tube machine pore-forming, the aperture is generally greater than 100mm, and assurance bagging Grouting Pipe can be put into by immersed tube; Can adopt the construction of lantern ring type immersed tube when the construction super long pile, it is excessive to avoid the hole body to tilt;
2) cloth bag 1 is enclosed within outside the Grouting Pipe 2, prick one Cowhells button or thin galvanized wire along the Grouting Pipe length direction every 30~50cm, with the cloth bag colligation on Grouting Pipe, to guarantee that cloth bag enters in the hole smoothly, Grouting Pipe 2 lower ends are by plug 6 sealings, cloth bag 1 lower end colligation is on Grouting Pipe end locating piece 3, the upper end colligation is on Grouting Pipe neck positioning sleeve 4, Grouting Pipe neck positioning sleeve 4 is enclosed within on Grouting Pipe 2 outer walls, Grouting Pipe end locating piece 3 is positioned at Grouting Pipe 2 bottoms, is provided with injected hole on Grouting Pipe 2 bottom tube walls.
3) Grouting Pipe and the Grouting Pipe positioning element that will be with cloth bag inserts in the stake hole, Grouting Pipe neck positioning sleeve 4 is placed the design elevation place of bag pile in the hole 5, Grouting Pipe end locating piece 3 places 5 bottoms, a hole, to cloth bag 1 internal pressure slip casting, grouting pressure is generally 0.2~0.5Mpa from Grouting Pipe 2.
In the time of in slurries enter into cloth bag, along with entering of slurries, the cloth bag of bottommost begins to expand, and rise Cowhells button or the galvanized wire of colligation disconnected on the Grouting Pipe surface, the soil body around the extruding, slowly promote Grouting Pipe after reaching 0.2~0.5Mpa pressure, in cloth bag, be injected into the slurries of design flow, Grouting Pipe is proposed, rely on ground, Grouting Pipe bottom plug 6 and the neck positioning sleeve 4 that is enclosed within outside the Grouting Pipe to peg graft, return on the slurries in the shutoff cloth bag, guarantee that slurries are controlled at formation pile body 7 in the cloth bag effectively.
Embodiment 2: referring to Fig. 2, Fig. 2 has shown the forming process of shallow embedding bag pile in the homogeneous weak soil.
The method of present embodiment is substantially the same manner as Example 1, difference is, in described step 2, described Grouting Pipe is by Grouting Pipe body 21, guide pipe 22 and slip casting rifle head are formed, merogenesis is provided with injected hole vertically on guide pipe 22 tube walls, described slip casting rifle head comprises the short tube 10 of an external diameter less than above-mentioned guide pipe 22 internal diameter of tube body, short tube 10 inserts in the guide pipe 22, on the tube wall of short tube 10, be provided with rifle head injected hole 11, sealing only starches piston 12 between being provided with guide pipe 22 bodys and short tube 10 on the short tube tube wall on rifle head injected hole 11 both sides, described short tube 10 lower end closed, the upper end is connected with Grouting Pipe body 21.Cloth bag 1 is enclosed within outside guide pipe 22 bodys, and merogenesis colligation vertically is on the tube wall between adjacent two injected holes, tighten respectively on guide pipe 22 bodys at the cloth bag two ends.
In described step 4, slip casting rifle head pursues joint slip casting in cloth bag 1 from bottom to top by the injected hole of guide pipe 22 bodys, along with entering of slurries, the cloth bag of bottommost begins to expand, the soil body around the cloth bag of expansion begins to push, and just colligation is risen disconnected at the Cowhells button or the galvanized wire 9 on Grouting Pipe body surface, after every joint is annotated design pressure, promote slip casting rifle head, pour down a joint, until cloth bag is filled with, form a complete pile body.
Select for use about φ 50mm at described guide pipe 22 bodys of present embodiment, wall thickness 3.5~4.0mm, compressive strength is not less than the high-quality pvc pipe of 1.0Mpa, pvc pipe is cut a hole the injected hole of 6~9 φ 3~5mm vertically on tube wall every 30~50cm, be with the elastic tape 8 that injected hole can be blocked in the injected hole position, during slip casting, slurries enter in the cloth bag from injected hole, and slip casting is when finishing, because the existence of elastic tape 8 is arranged, slurries also can not backflow in the Grouting Pipe body.
The cloth bag of above-mentioned two embodiment is selected φ 300~400mm roll type for use, generally selects unit area 230g/m for use
2, CRB bursting strength 〉=5.5KN, effective aperture 0
900.07~0.5mm, tearing strength 〉=0.9KN, coefficient of permeability K=1 * 10
-2~10
-3Cm/s.
The problem of noting during slip casting of the present invention:
1) from bottom to top by joint slip casting, every joint can slowly promote Grouting Pipe body 21 when annotating design slurry amount and satisfying pressure condition, pours down a joint.For buried major diameter bag pile, when grouting amount surpasses 3m and grouting pressure and reaches designing requirement, can slowly promote Grouting Pipe body 21, put forward pipe speed and be controlled at 0.4~0.6m/min.
2) grouting pressure is generally 0.2~0.5Mpa, in case surpass design pressure, carries Grouting Pipe body 21 on should be in time.Carry on should stopping when grouting pressure descends in putting forward the pipe process, treat to continue slowly to promote Grouting Pipe body 21 after grouting pressure returns to designing requirement.
3) the slurries injection rate should be according to the control of factors such as expanded diameter and eyelet quantity, size, and the injection rate of general minor diameter, shallow embedding stake is controlled at 10~12L/min; The injection rate of major diameter, buried stake is controlled at 50~75L/min.
When 4) grouting amount and pressure all meet design requirement, can extract Grouting Pipe, flushing grouting pipeline and relevant device use to get hole slip casting ready.The slip casting of every hole finishes, and should open return valve before the dismounting Grouting Pipe, to discharge the pressure of filling system.