Device at the bottom of injection forming expanded bore pile and construction method thereof and expansion
Technical field
The present invention relates to the realm of building construction, is construction method at the bottom of a kind of expansion of applicable bored pile and expansion end device.
Background technology
Existing Post Grouting Technique is, by burying high-pressure slip-casting flexible pipe underground on different depth place, stake side reinforcing cage, after bored pile concreting, by pre-buried pipe, cement mortar is injected Pile side soil layer to improve a kind of technology of pile side friction.According to the result of some tests, think and can reach reasonable effect after post jacking process, can 30% ~ 70% be improved to the bearing capacity of single pile in fine grained soils; To the stake in coarse-grained soil, amplification can reach 60% ~ 120%.The shearing rigidity that side frictional resistance effect after mud jacking shows as side friction raising and Pile side soil improves; Thus after shift value when making frictional resistance give full play to moves, this just means that the toughness of stake increases.But stake rear flank slurry injection technique also Shortcomings part, i.e. the flow path of uncontrollable slurries, easily running pulp phenomenon occurs, Reliability comparotive is poor.
Existing expanded bore pile often needs to adopt special plant equipment to carry out pore-forming at the bottom of expansion, thus reach the object improving pile body uplift resistance, but expand the complex process at the end, construction cost is high, simultaneously because the collapse hole phenomenon caused after soil body reaming causes pile quality instability to be also cause existing expanded bore pile to be difficult to the major reason promoted.
Although, open on 07 25th, 2012, document number is the Chinese invention patent of CN102605773, disclose construction method and the extruding-spreading device thereof of injection forming bell-out bored pile, this a kind of extruding-spreading device, comprise flange, this flange is vertically arranged the some distributing bars distributed ringwise, on this flange, also vertical welding one velamen is trapped among the steel pipe between described distributing bar, the outer wall being close to described steel pipe is wound with grouting tube, steel pipe outward also cover have one between steel pipe and distributing bar, and grouting tube bottom is wrapped in interior cylindrical geotechnological cloth bag, these upper and lower two ends of geotechnological cloth bag are all fixed on steel pipe by larynx hoop.As can be seen here, in this technical scheme, need a steel pipe, need first by steel-pipe welding on the bottom of reinforcing cage, and then be enclosed within outside steel pipe by geotechnological cloth bag, complicated structure, construction technology is also more loaded down with trivial details.
Therefore, how to provide a kind of construction technology simple, convenient, stake soil interlocking can be increased substantially, improving device at the bottom of the injection forming expanded bore pile of bearing capacity and construction method thereof and expansion is those skilled in the art's technical problems urgently to be resolved hurrily.
Summary of the invention
The object of the present invention is to provide device at the bottom of a kind of injection forming expanded bore pile and construction method thereof and expansion, its construction technology is simple, stake soil interlocking can be increased substantially, improve bearing capacity.
To achieve the above object, the present invention adopts following technical scheme:
A kind of expansion end device, comprise geotechnological cloth bag and Grouting Pipe, described geotechnological cloth bag is sheathed on the bottom outside of reinforcing cage, the upper and lower end of described geotechnological cloth bag fixes with the bottom of described reinforcing cage respectively, the middle part of described geotechnological cloth bag is tightened with some roads elastic cord, described geotechnological cloth bag entirety is in hollow cylinder, described geotechnological cloth bag is at least double-decker, upper lower sealing and at least have for holding the inner chamber of injection slurry, one end of described Grouting Pipe is connected with described geotechnological cloth bag, the external slip casting source of the other end of described Grouting Pipe.
Preferably, in device at the bottom of above-mentioned expansion, cuff cloth bag is offered on the top of described geotechnological cloth bag, and the top of described cuff cloth bag has opening, the bottom of described cuff cloth bag and the inner space of described geotechnological cloth bag that the one end for described Grouting Pipe is inserted.
Preferably, in device at the bottom of above-mentioned expansion, the quantity of described cuff cloth bag is two.
Preferably, in device at the bottom of above-mentioned expansion, one end of described Grouting Pipe arranges one with the slurry casting machine of injected hole.
Preferably, in device at the bottom of above-mentioned expansion, described cuff cloth bag is arranged at the middle and upper part of described geotechnological cloth bag.
Preferably, in device at the bottom of above-mentioned expansion, the diameter 200-300mm larger than the diameter of described reinforcing cage of described geotechnological cloth bag.
Preferably, in device at the bottom of above-mentioned expansion, described Grouting Pipe is iron pipe.
The invention also discloses a kind of injection forming expanded bore pile, it forms by being provided with to build as the reinforcing cage of device at the bottom of the expansion in claim 1 ~ 7 as described in any one.
The invention also discloses a kind of construction method of injection forming expanded bore pile, comprise the steps:
Step one, the arranged outside in the bottom of reinforcing cage is as in claim 1 ~ 7 as described in any one
Expansion at the bottom of device, specifically comprise:
Step 1-1, is sheathed on the bottom outside of reinforcing cage by described geotechnological cloth bag, and described geotechnological cloth bag
Bottom and the distance of the reserved 500mm in bottom (i.e. the bottom of the bottom of reinforcing cage) of reinforcing cage;
Step 1-2, adopts rope 5 that the upper and lower end of described geotechnological cloth bag is solid mutually with the bottom of reinforcing cage
Fixed, the middle part of described geotechnological cloth bag adopts some roads elastic cord to tighten, and makes geotechnological cloth bag and steel
The bottom of muscle cage is closely connected;
Step 2, transfers by bottom put in place with the reinforcing cage expanding end device, and concrete perfusion inward;
Step 3, after concrete curing 6h ~ 7h, start slip casting, whole slip casting process is divided and is carried out for 3 times,
Every minor tick 15 ~ 20 minutes, the geotechnological cloth bag expanding end device is formed full under the filling of cement paste
Cylindrical slip casting bag structure, its diameter constantly to expand expansion along with the injection of cement grout, squeezes thereupon
Pressure surrounding concrete also encrypts surrounding soil, final formation stake end enlarged footing.
Preferably, in the construction method of above-mentioned injection forming expanded bore pile, described cement paste adopts P42.5 cement.
Device at the bottom of injection forming expanded bore pile provided by the invention and construction method thereof and expansion, end device is expanded by the arranged outside of the bottom at reinforcing cage, bottom is transferred with the reinforcing cage expanding end device and puts in place, and concrete perfusion inward, Deng starting slip casting after concrete curing, the geotechnological cloth bag expanding end device forms full cylindrical slip casting bag structure under the filling of cement paste, its diameter constantly to expand expansion along with the injection of cement grout, extrude surrounding concrete thereupon and encrypt surrounding soil, final formation stake end enlarged footing, injection forming expanded bore pile not only embodies the advantage of existing expanded bore pile, also be to be applicable to multiple soil layer area, not by the impact of the unfavorable factors such as collapse hole, construction technology is simple simultaneously, without the need to macromechanical squeeze equipment, slip casting good stability, slurries can control, not running pulp, bearing power increase is obvious, a kind of new and effective, economic pile-type reliably.
The invention provides a kind of novel pile-type and construction method thereof, adopt existing Post Grouting Technique, utilize the boundary constraint of geotechnological cloth bag to control slurries simultaneously, can regularly flow, both the space between stake soil had been filled with, produce layer compaction effect and invigoration effect by slurries to surrounding soil again, thus reach the object improving stake anti-pulling capacity, this new pile-type goes for multiple soil layer area.
Accompanying drawing explanation
At the bottom of injection forming expanded bore pile of the present invention and construction method thereof and expansion, device is provided by following embodiment and accompanying drawing.
Fig. 1 is the structural representation of device at the bottom of expansion of the present invention;
Fig. 2 is the A-A cross-sectional schematic of Fig. 1;
Fig. 3 A is the structural representation of construction method in step injection forming expanded bore pile for the moment of injection forming expanded bore pile of the present invention;
Fig. 3 B is the schematic top plan view of Fig. 3 A;
Fig. 4 is the structural representation of the injection forming expanded bore pile of construction method when step 2 of injection forming expanded bore pile of the present invention;
Fig. 5 is the structural representation of the injection forming expanded bore pile of construction method when step 3 of injection forming expanded bore pile of the present invention;
In figure, 1-geotechnique cloth bag, 11-internal layer, 12-skin, 2-Grouting Pipe, 3-cuff cloth bag, 4-reinforcing cage, 5-rope, 6-elastic cord, 7-slurry casting machine.
Detailed description of the invention
Below with reference to accompanying drawings the present invention is described in more detail, which show the preferred embodiments of the present invention, should be appreciated that those skilled in the art can revise the present invention described here and still realize beneficial effect of the present invention.Therefore, following description is appreciated that extensively knowing for those skilled in the art, and not as limitation of the present invention.
In order to clear, whole features of practical embodiments are not described.They in the following description, are not described in detail known function and structure, because can make the present invention chaotic due to unnecessary details.Will be understood that in the exploitation of any practical embodiments, a large amount of implementation detail must be made to realize the specific objective of developer, such as, according to regarding system or the restriction about business, change into another embodiment by an embodiment.In addition, will be understood that this development may be complicated and time-consuming, but be only routine work to those skilled in the art.
For making object of the present invention, feature becomes apparent, and is further described the specific embodiment of the present invention below in conjunction with accompanying drawing.It should be noted that, accompanying drawing all adopts the form that simplifies very much and all uses non-ratio accurately, only in order to object that is convenient, the aid illustration embodiment of the present invention lucidly.
Refer to 1 and Fig. 2, and incorporated by reference to Fig. 3 A, present embodiments provide a kind of injection forming expanded bore pile, it is built by the reinforcing cage being provided with expansion end device and forms.Device at the bottom of described expansion, be arranged at the outside of cage at the bottom of the bottom of reinforcing cage 4 and reinforcing bar, device at the bottom of described expansion comprises geotechnological cloth bag 1 and Grouting Pipe 2, described geotechnological cloth bag 1 is sheathed on the bottom outside of reinforcing cage 4, the diameter 200-300mm larger than the diameter of described reinforcing cage of described geotechnological cloth bag, described geotechnological cloth bag 1 upper, lower end is passed through to be iron wire in rope 5(the present embodiment with the bottom of described reinforcing cage 4 respectively) fix, described geotechnological cloth bag 1 entirety is in hollow cylinder, described geotechnological cloth bag 1 is at least double-decker, upper lower sealing and at least have one for holding the inner chamber of injection slurry, that described geotechnological cloth bag is connected to form by upper and lower port sealing by internal layer 11 and outer 12 in the present embodiment.The middle part of described geotechnological cloth bag 1 is tightened with some roads elastic cord 6, because elastic cord 6 is flexible in the process of slip casting, therefore, geotechnological cloth bag 1 can distending, one end of described Grouting Pipe 2 is inserted in described geotechnological cloth bag 1, the external slip casting source of the other end of described Grouting Pipe 2.
Preferably, in the present embodiment, cuff cloth bag 3 is offered on the top of described geotechnological cloth bag 1, and the top of described cuff cloth bag 3 has opening, the bottom of described cuff cloth bag 3 and the inner space of described geotechnological cloth bag 1 that the one end for described Grouting Pipe 2 is inserted.
Preferably, in the present embodiment, the quantity of described cuff cloth bag 3 is two, so arranges and cement paste can be made to flow into more evenly, reposefully in geotechnological cloth bag 1.Preferred further, described cuff cloth bag 3 is arranged at the middle and upper part of described geotechnological cloth bag.So arrange and cement paste can be made further to flow into more evenly, reposefully in geotechnological cloth bag 1.
Preferably, in the present embodiment, one end of described Grouting Pipe 2 is provided with the slurry casting machine 7 of injected hole, evenly flows in geotechnological cloth bag 1 to make cement paste.
Preferably, in the present embodiment, described Grouting Pipe 2 is iron pipe.
Refer to Fig. 1 to Fig. 5, the present embodiment is also supplied to a kind of construction method of injection forming expanded bore pile, comprises the steps:
Step one, the arranged outside in the bottom of reinforcing cage 4 expands end device as above, as shown in Figure 3 A and Figure 3 B, specifically comprises:
Step 1-1, is enclosed within described geotechnological cloth bag 1 on the bottom of reinforcing cage 4, and described geotextiles
The distance of 500mm is reserved in the bag bottom of 1 and the bottom of reinforcing cage 4, is beneficial to follow-up concrete casting
Instead smoothly when building to starch, take pile bottom sediment out of;
Step 1-2, adopts rope 5 by the described upper and lower end of geotechnological cloth bag 1 and the end of reinforcing cage 4
Portion fixes, and the middle part of described geotechnological cloth bag 1 adopts some roads elastic cord 6 to tighten, and makes soil
The bottom of work cloth bag 1 and reinforcing cage 4 is closely connected;
Step 2, utilizes construction process for bored pile that bottom is transferred put in place with the reinforcing cage 4 expanding end device, and concrete perfusion inward, as shown in Figure 4;
Step 3, after concrete curing 6h ~ 7h, starts slip casting, and for preventing geotechnological cloth bag 1 from being burst, whole slip casting process is divided and carried out for 3 times, and every minor tick 15 ~ 20 minutes, is beneficial to dribbling of the grouting pressure in geotechnological cloth bag 1.The geotechnological cloth bag 1 expanding end device forms full cylindrical slip casting bag structure under the filling of cement paste, its diameter constantly to expand expansion along with the injection of cement grout, extrude surrounding concrete thereupon and encrypt surrounding soil, final formation stake end enlarged footing, as shown in Figure 5, thus increased substantially stake soil interlocking, improve the bearing capacity of uplift pile.
Preferably, in the construction method of above-mentioned injection forming expanded bore pile, described cement paste adopts P42.5 cement.PO42,5 refer to Portland cement strength grade, and the 28 days compressive strength standard being exactly Portland cement are not less than 42.5 MPas.
In sum, device at the bottom of injection forming expanded bore pile provided by the invention and construction method thereof and expansion, end device is expanded by the arranged outside of the bottom at reinforcing cage, bottom is transferred with the reinforcing cage expanding end device and puts in place, and concrete perfusion inward, Deng starting slip casting after concrete curing, the geotechnological cloth bag expanding end device forms full cylindrical slip casting bag structure under the filling of cement paste, its diameter constantly to expand expansion along with the injection of cement grout, extrude surrounding concrete thereupon and encrypt surrounding soil, final formation stake end enlarged footing, injection forming expanded bore pile not only embodies the advantage of existing expanded bore pile, also be to be applicable to multiple soil layer area, not by the impact of the unfavorable factors such as collapse hole, construction technology is simple simultaneously, without the need to macromechanical squeeze equipment, slip casting good stability, slurries can control, not running pulp, bearing power increase is obvious, a kind of new and effective, economic pile-type reliably.
The invention provides a kind of novel pile-type and construction method thereof, adopt existing Post Grouting Technique, utilize the boundary constraint of geotechnological cloth bag to control slurries simultaneously, can regularly flow, both the space between stake soil had been filled with, produce layer compaction effect and invigoration effect by slurries to surrounding soil again, thus reach the object improving stake anti-pulling capacity, this new pile-type goes for multiple soil layer area.
Obviously, those skilled in the art can carry out various change and modification to the present invention and not depart from the spirit and scope of the present invention.Like this, if these amendments of the present invention and modification belong within the scope of the claims in the present invention and equivalent technologies thereof, then the present invention is also intended to comprise these change and modification.