CN111945715A - Prefabricated pipe pile for construction of ultra-long stiff composite pile and construction method - Google Patents

Abstract

The invention discloses a prefabricated pipe pile and a construction method for the construction of super-long composite piles. Flange plate and convex part, the two flange plates are respectively arranged at the butt joints of two adjacent pile sections, the two pile sections are connected by the flange plate, and the convex part is connected to one of the two adjacent pile sections. One end of the segment is connected and inserted into the inner ring at one end of the other pile segment. The invention has the advantages of simple and convenient operation, high construction speed, better bearing performance, and firmer connection and fixation.

Description

A kind of prefabricated pipe pile and construction method for super-long composite pile construction

technical field

The invention relates to the technical field of building construction, in particular to a prefabricated pipe pile and a construction method for the construction of super-long composite piles.

Background technique

When constructing buildings (structures) on soft soil foundations, the natural foundation bearing layer often cannot meet the requirements of foundation strength and structural deformation, so it is necessary to take certain strengthening measures for soft soil foundations, and stiff composite piles are one of them. A widely used pile foundation form.

Stiff composite piles are a kind of piles composed of scattered piles (piles formed from scattered materials such as gravel, sand, steel slag, slag or brick and tile fragments), flexible piles (generally cement-soil mixing piles) and rigid piles (generally It is a new type of pile composed of two or three kinds of reinforced concrete precast piles or bored piles. It combines the advantages of scattered piles, flexible piles and rigid piles, so that the rigid piles of the pile core bear all the vertical loads, and then transfer the load to the surrounding flexible piles, and then the flexible piles use the larger friction surface to transfer the piles to the piles. Therefore, the single pile has high ultimate bearing capacity, and has the advantages of low cost, convenient construction, stable and reliable pile quality and no pollution. It is a new type of pile with great development prospects.

During the construction of stiff composite piles, it is necessary to insert rigid piles into loose piles or flexible piles. For super-long composite piles, when the rigid piles are in the form of bored cast-in-place piles, the construction technology is relatively mature and there is no major technical difficulty; and when the prefabricated piles are used, due to the limitation of the pile length, it is necessary to Take the method of first section production, and then on-site connection. At present, the main methods of connecting segmented prefabricated piles in China are: hoop welding, expansion bolt connection, pin connection, etc. The hoop welding method is time-consuming and labor-intensive, and the quality of the simple welding is difficult to control, which is easy to cause the problem of insufficient connection strength of the pile body. Expansion bolt connection and pin connection have problems such as difficult alignment of screw holes and pin holes, insufficient horizontal shear strength, and low safety. Therefore, a simpler and more reliable pile section connection method is needed, which can overcome the above technical problems. Ensure that the prefabricated pile can reach the predetermined design length and play a bearing role.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a prefabricated pipe pile and a construction method for the construction of super-long composite piles in view of the above-mentioned defects in the prior art, which are simple and convenient to operate, fast in construction, and have better performance. The load-bearing performance is better, and the connection and fixation are more firm.

The technical scheme adopted by the present invention for solving the above-mentioned technical problems is:

A prefabricated tubular pile used for construction of super-long composite piles, comprising a plurality of pile sections spliced in sequence from bottom to top, connecting devices are connected between the pile sections; the connection between the pile sections is realized through the connecting device;

The connecting device includes two flanges and a convex part, the two flanges are respectively arranged at the butt joints of two adjacent pile sections, the two pile sections are connected by a flange, and the convex part is connected to the two adjacent piles. One of the segments is connected at one end and inserted into the inner ring at one end of the other.

According to the above technical solution, the convex portion is a circular steel cylinder.

According to the above technical solution, the wall thickness of the annular steel cylinder is 1.5 cm to 3 cm, of which 2 cm is preferred.

According to the above technical solution, the insertion length of the convex portion is 35-45 cm.

According to the above technical solution, a plurality of bolt holes are distributed on the flange along the circumferential direction, and the two butted flanges are connected by bolts, and the bolts penetrate into the corresponding bolt holes.

According to the above technical solution, the two butted flanges are an upper flange and a lower flange respectively.

According to the above technical solution, a steel ferrule is connected between the flange and the pile section, and the flange and the steel ferrule of the pile section are pre-welded as a whole.

A construction method using the above-mentioned prefabricated tubular pile for construction of super-long composite piles, wherein the plurality of pile sections are respectively bottom pile sections, middle pile sections and top pile sections connected in sequence from bottom to top; segment is one or more;

The construction method specifically includes the following steps:

1) Press the bottom pile section into the cement-soil mixing pile;

2) Lift the middle pile section and connect the bottom pile section through the connecting device, and then continue to press the middle pile section into the cement-soil mixing pile;

3) Lift the top pile section and connect the middle pile section through the connecting device, and then continue to press the top pile section to the design depth in the cement-soil mixing pile.

According to the above technical solution, in the steps 2) and 3), before the two pile sections are connected by the connecting device, high-strength resin is applied to the corresponding two butt flanges and the convex part; The protrusions are inserted and the two flanges are tightly connected with bolts.

According to the above technical scheme, the connection and pressing work between the pile sections need to be completed within 3 hours after the completion of the cement-soil mixing pile construction.

The present invention has the following beneficial effects:

The invention simplifies the connection method of the pipe piles and accelerates the construction speed through prefabricated sections and on-site connection. At the same time, the connection of the pile body is made firmer through the convex part and the flange plate, so as to obtain better horizontal and vertical bearing performance.

Description of drawings

1 is a schematic structural diagram of a jacking section in an embodiment of the present invention;

Fig. 2 is the structural schematic diagram of the middle pile section in the embodiment of the present invention;

Fig. 3 is the structural schematic diagram of the bottom pile section in the embodiment of the present invention;

Fig. 4 is the structural representation of the upper flange plate in the embodiment of the present invention;

Fig. 5 is the structural representation of the lower flange plate in the embodiment of the present invention;

In the figure, 1-bottom pile section, 2-middle pile section, 3-top pile section, 4-steel ferrule, 5-upper flange, 6-convex, 7-lower flange, 8-bolt hole .

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

Referring to Figures 1 to 5, a prefabricated tubular pile for construction of an ultra-long composite pile in an embodiment provided by the present invention includes a plurality of pile sections spliced sequentially from bottom to top, and each pile section is connected There is a connecting device; the connection between each pile section is realized through the connecting device;

The connecting device includes two flanges and a convex part 6, the two flanges are respectively arranged at the butt joints of two adjacent pile sections, the two pile sections are connected by the flange, and the convex part 6 is connected to the two adjacent pile sections. One of the adjacent pile segments is connected at one end and inserted into the inner ring at one end of the other pile segment.

Further, the convex portion 6 is a circular steel cylinder.

Further, the wall thickness of the annular steel cylinder is 1.5cm-3cm, wherein the wall thickness is preferably 2cm.

Further, the insertion length of the convex portion 6 is 35-45 cm, and the insertion length is preferably 40 cm, which can enhance the horizontal shear resistance of the pile body connection.

Further, a plurality of bolt holes 8 are distributed on the flange along the circumferential direction, and the two butted flanges are connected by bolts, and the bolts penetrate into the corresponding bolt holes 8 .

Further, the two butted flanges are the upper flange 5 and the lower flange 7 respectively.

Further, a steel ferrule is connected between the flange and the pile section, and the flange and the steel ferrule 4 on the pile section are pre-welded as a whole.

A construction method using the above-mentioned prefabricated tubular piles for the construction of super-long composite piles, the plurality of pile sections are respectively bottom pile section 1, middle pile section 2 and top pile section 3 connected sequentially from bottom to top ; One or more intermediate pile sections 2;

The construction method specifically includes the following steps:

1) Press the bottom pile section 1 into the cement-soil mixing pile;

2) Lift the middle pile section 2 and connect it with the bottom pile section 1 through the connecting device, and then continue to press the middle pile section 2 into the cement-soil mixing pile;

3) Lift the top pile section 3 and connect it with the middle pile section 2 through the connecting device, and then continue to press the top pile section 3 to the design depth in the cement-soil mixing pile.

Further, in the steps 2) and 3), before the two pile sections are connected by the connecting device, high-strength resin is smeared on the corresponding two butt flanges and the convex part 6; Section 6 is inserted, and the two flanges are tightly connected with bolts.

Further, the bolt holes 8 of the flange plate are evenly distributed along the disk, and their diameter and spacing can be customized in advance according to actual construction needs.

Further, it is necessary to complete the connection and pressing work between the various pile sections within 3 hours after the completion of the construction of the cement-soil mixing pile.

The working principle of the present invention: the connecting device includes an upper flange 5, a lower flange 7 and bolts, and the upper flange 5 and the lower flange 7 are pre-welded with their corresponding steel ferrules 4 as a whole. The upper flange 5 is provided with bolt holes 8 and a convex portion 6, the convex portion 6 is a circular steel cylinder, which is pre-welded with the upper flange 5 and can be inserted into the lower flange 7. . The lower flange 7 is provided with bolt holes 8, which correspond to the bolt holes 8 of the upper flange 5 one-to-one. Said bolts connect the upper and lower flanges 7 .

The insertion of the convex part 6 into the lower flange 7 will greatly enhance the horizontal bearing capacity of the connection of the pile body, and the flange plate will greatly improve the vertical bearing capacity of the pile body.

The present invention also provides a prefabricated pipe pile connection method for super-long composite pile construction, wherein the upper flange 5 is located at the bottom of the upper pile section, and the lower flange 7 is located at the lower pile section the top of. In actual construction, firstly press the lower pile section into the cement-soil mixing pile, stop the pile pressing when its top is 1 meter above the ground, lift the upper pile section to a vertical state, and coat the upper section with high-strength resin. The flange plate 5, the lower flange plate 7 and the convex part 6 are lowered slowly, and the convex part 6 of the upper flange plate 5 is inserted into the lower pile section, and the bolt holes of the upper flange plate 5 and the lower flange plate 7 are inserted. 8 correspond one by one, and finally lock them tightly with bolts, and the connection between the pile sections is completed at this time.

But it is worth noting that the outer diameter of the flange is larger than the outer diameter of the cylindrical pile body. Although it will provide better vertical bearing performance, it will also affect the pressing speed of the pipe pile. Therefore, it should be used in cement and soil. The connection and pressing of the pile sections are completed within 3 hours after the construction of the mixing pile is completed. At this time, the cement and soil still have a certain fluidity. The side friction resistance support function can still be well exerted.

Stiff composite piles are used as the building foundation in the silty clay development area. The flexible piles are cement-soil mixing piles with a diameter of 900 mm and a design length of 40 meters. The rigid piles are prefabricated PHC pipe piles with a design length of 39 meters and an outer diameter of 600 meters. mm, wall thickness 130 mm.

Referring to Figures 1 to 5, the construction sequence is to first apply the cement-soil mixing pile, and press the bottom pile section 1 vertically within 3 hours after the construction is completed. When the top of the bottom pile section 1 is 1 meter from the ground, stop pressing. Then lift the middle pile section 2 vertically, apply high-strength resin evenly to the contact position of the upper flange 5 and the lower flange 7, and insert the convex part 6 of the middle pile section 2 into the flange 7 of the bottom pile section 1 and make the bolt holes 8 of the upper and lower flanges correspond one by one, and then use bolts to connect them tightly.

Continue to press in the middle pile section 2, when its top is 1 meter from the ground, stop pressing in. Lift the top pile section 3 vertically, apply high-strength resin evenly to the contact position of the upper flange 5 and the lower flange 7, and insert the convex part 6 of the top pile section 3 into the flange 7 of the middle pile section 2 , and make the bolt holes 8 of the upper flange and the lower flange correspond one by one, then use bolts to connect them tightly, and continue to press the top pile section 3 to the design depth.

The present invention mainly provides a prefabricated pipe pile connection device and connection method for stiff composite pile construction. Compared with the traditional prefabricated pile connection method, the construction is more convenient and faster, and the safety risk is smaller. The existence of the ring-shaped steel plate makes the joint of the pile body bear a certain horizontal tangential load, and the whole body of the pile body is firmer, and the flange plate will make the side of the pile body appear concave and convex shape, which will enhance the vertical ultimate bearing capacity of the pile body. Reduce pile top settlement. Therefore, the invention has certain practical application value for improving the bearing performance of the stiff composite pile.

The above are only the preferred embodiments of the present invention, of course, the scope of the rights of the present invention cannot be limited by this, so the equivalent changes made according to the scope of the patent application of the present invention still belong to the protection scope of the present invention.

Claims (9)

1. a prefabricated pipe pile for super-long stiffness composite pile construction, is characterized in that, comprises a plurality of pile sections spliced sequentially from bottom to top, and is connected with connecting device between each pile section; The connecting device includes two flanges and a convex part, the two flanges are respectively arranged at the butt joints of two adjacent pile sections, the two pile sections are connected by a flange, and the convex part is connected to the two adjacent piles. One of the pile segments is connected at one end and inserted into the inner ring at one end of the other pile segment. 2 . The prefabricated tubular pile for construction of super-long composite piles according to claim 1 , wherein the convex portion is a circular steel cylinder. 3 . 3 . The prefabricated tubular pile for construction of super-long composite piles according to claim 2 , wherein the wall thickness of the annular steel cylinder is 1.5 cm to 3 cm. 4 . 4 . The prefabricated tubular pile for construction of super-long composite piles according to claim 1 , wherein the insertion length of the convex portion is 35-45 cm. 5 . 5. The prefabricated pipe pile for construction of super-long composite piles according to claim 1, wherein a plurality of bolt holes are distributed along the circumferential direction on the flange, and between the two butted flanges By bolting, the bolts are inserted into the corresponding bolt holes. 6. The prefabricated pipe pile for construction of super-long composite piles according to claim 1, characterized in that, a steel ferrule is connected between the flange plate and the pile section, and the flange plate and the steel sleeve of the pile section are connected with each other. The hoop is pre-welded into one piece. 7. A construction method using the prefabricated tubular pile for super-long composite pile construction according to claim 1, wherein the plurality of pile sections are respectively bottom pile sections and intermediate piles connected sequentially from bottom to top segment and top pile segment; The construction method specifically includes the following steps: 1) Press the bottom pile section into the cement-soil mixing pile; 2) Connect the middle pile section and the bottom pile section through the connecting device, and then continue to press the middle pile section into the cement-soil mixing pile; 3) Connect the top pile section and the middle pile section through the connecting device, and then continue to press the top pile section to the design depth in the cement-soil mixing pile. 8. The construction method according to claim 7, wherein, in the steps 2) and 3), before the two pile sections are connected by the connecting device, high-strength resin is applied to the corresponding two butt joints on flanges and bosses. 9 . The construction method according to claim 7 , wherein the connection and pressing work between the pile sections need to be completed within 3 hours after the completion of the cement-soil mixing pile construction. 10 .

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