Make the method for PHC tubular pile in soft soil region through chambering and grouting
Technical field
The present invention relates to the technical field on the work basis in the civil works, particularly a kind of mode by reaming forms hole at the high-strength Prestressed Pipe Pile periphery, adopts along with pile tube sinks to adopting surplus slurry, cement paste, cement mortar grouting and the method for the making PHC tubular pile in soft soil region through chambering and grouting of the high-bearing capacity, high uplift resistance, high horizontal force resistant and the good seepage-proof property that form.
Background technology
Along with The development in society and economy, pre-tensioning system high-strength prestressed concrete pipe pile (being called for short the PHC pile tube) is a kind of stake type commonly used, as shown in Figure 1.The annual production in the whole nation in 2008 surpasses 300,000,000 meters, has been widely used in all kinds of buildings.Advantage such as that the PHC pile tube has is high-strength, economy, duration are fast, its pile strength can reach 80MPa, far above other foundation piles.The bearing capacity of stake is got the low value of following two factors: the one, and pile strength, the 2nd, but the frictional resistance of stake and soil, the PHC pile strength can reach 80MPa, far above the frictional resistance of stake with soil, so pile strength fails effectively to bring into play.To this problem, adopt kinds of processes both at home and abroad, in the hope of improving its bearing capacity, the employing high-pressure rotary jet grouting pile lock pin that has, the deep-mixed pile lock pin that has, the pile sinking grouting behind shaft or drift lining that has and first reaming be technology such as pile sinking and then slip casting again.Though like that having certain effect often needs plurality of devices to form a complete set of, working procedure is complicated and the construction effect is low, is difficult to obtain the good social economic benefit.So, how to adopt better simply construction technology to improve the mechanical property of PHC pile tube in soft clay area, become a stubborn problem.
Summary of the invention
For solving the problem that exists in the above-mentioned technology, the invention provides a kind of method of making PHC tubular pile in soft soil region through chambering and grouting, adopt the mode of grouting to improve the bearing capacity of PHC pile tube by structure more easily, be beneficial to reach the purpose that improves effect, saves investment.
For achieving the above object, the technical solution used in the present invention provides a kind of method of making PHC tubular pile in soft soil region through chambering and grouting, and this method includes following steps:
Bottom stake end at construction sinking PHC pile tube is provided with the enlarged footing plate, and the area of enlarged footing plate is greater than the sectional area of PHC pile tube, and employing is connected in the bottom stake end of HC pile tube greater than the steel plate of the sectional area of PHC pile tube;
Form the space by the enlarged footing plate in the middle of all soil of stake and PHC pile tube in construction sinking PHC pile tube process, by the Grouting Pipe of grouting grouting equipment grouting agent is injected the space then, Grouting Pipe is buried following 2 meters;
In construction sinking PHC pile tube process, reserve and be connected with grout pipe with grout pipe, grout pipe is in the outside of PHC pile tube, and sink synchronously with the PHC pile tube, after treating that grouting agent final set has preliminary intensity, then utilize the grouting grouting equipment once more by reserving the grout pipe secondary grouting, the grout hardens layer that forms with the compactness of strengthening grouting agent.
Effect of the present invention is to provide a kind of resistance to compression, resistance to plucking of better simply raising PHC pile tube, the method for horizontal force resistant in soft clay area; give full play to tubular pile body intensity; and can reduce native friction in the pile driving process to pile body; the anticorrosive paint of protection pile body; the pile body fine fisssure is sewed with the seepage flow protective effect, improves impervious effect.The bearing capacity of PHC pile tube can bring up to 150% ~ 300%, and comprehensive cost can save 20 ~ 60%.Obviously improved the bearing capacity of PHC pile tube, given full play to the high-strength performance of the pile shaft material of PHC pile tube, reduced investment outlay and improve economic results in society.
Description of drawings
Fig. 1 is conventional PHC pile tube schematic diagram;
Fig. 2 is a reaming schematic diagram of the present invention;
Fig. 3 is a grouting schematic diagram of the present invention;
Fig. 4 is four folding segment structure schematic diagrames of grout pipe of the present invention;
Fig. 5 is the connection diagram of end plate of the present invention and welding steel;
Fig. 6 is a secondary grouting schematic diagram of the present invention;
Fig. 7 is the structure chart of square enlarged footing of the present invention;
Fig. 8 is the structure chart of triangle enlarged footing of the present invention;
Fig. 9 is the structure chart of circular enlarged footing of the present invention;
Figure 10 is the structure chart of oval enlarged footing of the present invention.
Among the figure:
1, PHC pile tube 2, grout hardens layer 3, enlarged footing plate
4, all soil 5 of stake, space 6, Grouting Pipe
7, grouting agent 8, grout pipe 11, prestressed reinforcement
12, end plate 14, pile end grouting hole 15, stake side injected hole
16, grouting grouting equipment
The specific embodiment
Reaching embodiment in conjunction with the accompanying drawings is illustrated the method for making PHC tubular pile in soft soil region through chambering and grouting of the present invention.
Stake end at construction sinking PHC pile tube 1 adopts enlarged footing plate 3, and the area of enlarged footing plate 3 is greater than the sectional area of PHC pile tube, adopts the bottom stake end that is connected in HC pile tube 1 greater than the steel plate of the sectional area of PHC pile tube, as shown in Figure 2.
The shape of enlarged footing plate 3 according to the difference of formation properties, can have multiple shapes such as square, circular, triangle or ellipse, the area of enlarged footing plate 3 can be PHC pile tube 1 cross-sectional area 1.5-3 doubly.Described enlarged footing plate 3 can adopt the area that strengthens end plate 12 or directly will be greater than two kinds of forms of steel plate welding of PHC pile tube 1 cross-sectional area, and the enlarged footing plate 3 of two kinds of forms is connected with prestressed reinforcement 11 or end plate 12 in the PHC pile tube 1 respectively; When described increasing end plate is made at PHC pile tube 1, substitute the end plate 12 of PHC pile tube 1 one ends, be connected with the end plate preformed hole that strengthens end plate by the prestressed reinforcement in the PHC pile tube 1 11, as shown in Figure 5.Described welding steel is when PHC pile tube 1 pile sinking, and the welding steel by end plate in the PHC pile tube 1 12 and enlarged footing plate 3 is welded to connect.
In construction sinking PHC pile tube 1 process, in the middle of stake week native 4 and PHC pile tube 1, form space 5, by the Grouting Pipe 6 that is communicated with grouting grouting equipment 16 grouting agent 7 is injected space 5, as shown in Figure 3 by enlarged footing plate 3.Grouting Pipe 6 is buried following 2 meters and is connected with grout pipe 8, and Grouting Pipe 6 materials can adopt polyethylene pipe or galvanized pipe, and this Grouting Pipe 6 can reuse, and grouting pressure is not limit, as long as guarantee that injecting paste material can normally flow out.Grouting agent 7 can be cement paste, cement mortar or surplus slurry waste material, and cement adopts the normal silicate or the portland slag cement of 32.5 or 42.5 strength grades all can.
Reserving grout pipe 8 in construction sinking PHC pile tube 1 process is communicated with Grouting Pipe 6, the material of grout pipe 8 can adopt two kinds of polyethylene pipe or galvanized pipes, grout pipe 8 is located at the outside of PHC pile tube 1, and sink synchronously with PHC pile tube 1, along the stake limit per 4 meters fixing with steel wire and stake, note colligation again after need wait weld bond to cool off in PHC pile tube welding pile extension process as adopting polyethylene pipe, with non-ironing broken Grouting Pipe, and the bottom grouting port taked safeguard measure, avoid being full of in the filling process mud; Grout pipe 8 becomes four bendings at foot, reserves four grouting ports 14, as shown in Figure 4.Along in the length of PHC pile tube 1, reserve a stake side injected hole 15 every 1 meter below 6 meters at height of pile top; After treating that grouting agent 7 final set have preliminary intensity, once more with grouting agent 7 secondary groutings, as shown in Figure 6.Grouting pressure is 1-3MPa, with the compactness of strengthening grouting agent 7 and the influence that reduces the sclerosis drying shrinkage, solidifies the back and forms grout hardens layer 2; Secondary grouting after finishing by grouting in the pile driving process of PHC pile tube 1 and pile sinking, grout hardens layer 2 solidify back intensity can reach 3-15MPa.
That the shown PHC of the being pile tube 1 bottom enlarged footing plate 3 of Fig. 7-10 is respectively is square, triangle, circle and elliptical shape, the phantom drawing of sinking PHC pile tube 1 construction.