KR20020043484A - Concrete Filled Thin Tube Pile--CFTTP - Google Patents

Abstract

PURPOSE: Provided is a process for forming a thin pipe pile called CFTTP in order to eliminate disuse of used piles and to use temporary pile to fill concrete into a hole formed to produce a stem support when determining it is proper to utilize ground friction due to deep and hard ground. CONSTITUTION: The process for forming CFTTP(1) comprises standing a short thin pipe(2) galvanized on a soft ground; inserting a temporary pile applied with an insertion support band(10) at upper hole of the pipe(2); hammering then recovering the temporary pile; introducing concrete into the hole. If the depth digged by the pile is too deep, the pile is extracted then being provided the concrete to form the stem support. If it was not ensured desirable force for supporting the pile, the temporary pile should be inserted to reach a desirable depth after removing a perforated bolt from the insertion support band(10).

Description

Concrete Filled Thin Tube Pile--CFTTP}

If the ground of foundation floor is soft, it is designed as pile foundation instead of direct foundation. However, when the pile length is less than 6m, it is common to apply methods such as foundation of foundation, conversion of soil, soil improvement, ground compaction, etc.

However, all of these construction methods are difficult to construct and the construction cost is low, so they remain the blind spot of the basic construction method.

Since less than 6m long piles are not produced, there is a way to take the waste of cutting off the old product stakes in the ground where the hard ground level is jagged, but no one is trying this method.

Even if the ground condition is roughly grasped beforehand by the ground survey, it is difficult to know the scope and volume of the construction in advance because the pile length that secures the required bearing capacity is not the same.

Therefore, to overcome this problem, the CFTTP (1) of the present invention was developed with an indirect base designation of less than 6 m.

CFTTP (1) is a method of embedding a short tube (2) in the ground or soft ground that has not been filled and filling the inside with concrete, and then, if necessary, to form a mandrel (3).

Place a pipe (2) with a galvanized inner diameter of 255 mm and a thickness of 2-3 mm at the position to be piled, insert a temporary pile (6) with an outer diameter of 250 mm through the upper hole, and then drive the pile with a hammer. The tube 2, which is blocked by the penetration support band 10 settled in position, is driven into the ground at the same time as the temporary pile 6, and when the temporary pile 6 is recovered, the hollow tube 2 remains in the ground.

In the process of driving the temporary pile (6) in spite of the penetration of all the tube (2), if the predetermined pile support force is not secured, continue piling in the state of removing the through bolt 13 of the penetration support band (10) CFTTP (1) is generated by injecting concrete into a hole formed by injecting only the temporary pile 6 to a predetermined depth while leaving the tube 2 in place.

However, if the depth of driving the temporary pile (6) is too deep to be burdened, draw on the way, fill the concrete inside and chop the concrete into the temporary pile (6), the concrete from the end of the tube (2) to the soft ground To penetrate and seep the mandrel base (3) is formed.

After the compaction, the empty space in the tube 2 is filled with concrete to complete the reinforced CFTTP 1.

In this case, if the bearing capacity of the pile is not secured in the process of driving the temporary pile (6), it is checked by load test whether the frictional resistance of the mandrel support (3) and the bearing capacity increase due to the increase in the cross section satisfy a predetermined value.

The length of the tube (2) is 2-3m. If the length remains, remove the temporary pile (6), depending on the situation, cut it out or put only the tube (2) with a hammer.

The tube (2) is a temporary pile (6) due to the nature of the buried ground or soft ground to form a pile hole to prevent the soil from collapsing in the process of pouring concrete, and when the pile acts as a lateral force to the tensile stress generated in the cross section Correspondingly, the compacting pressure is lost to the upper soft ground in the process of compacting the concrete to prevent the concrete is ejected. The thin pipe (2) is infiltrated only to the upper soft layer only, and since most of the pile-type energy is infiltrated by the temporary pile (6) without any large resistance, the galvanized film is not damaged very much, and if the damaged door is rusted, the pile strength is insufficient. Efficiently estimate the concrete cross section so as not to.

The long-term permissible bearing capacity of CFTTP 1 having a diameter of 255 mm (concrete 28 days compressive strength 240 kgf / cm 2) is about 30 tf.

The penetration support band 10 is provided with a through bolt 13, a filling bolt 12, and a through bolt 13 at a point where the temporary pile 6 is embedded in 2m and 3m, but when the construction quantity is large, 2m each. , The temporary pile (6) fixedly welded to the penetration support band 10 in the position of 3m length, and the temporary pile (6) dedicated for compaction without the penetration support band 10 of about 6m in length may be prepared and installed separately have.

If the ground is not deep or the soft ground is deep, the basic approach is rather tricky. It's wasteful to cut the pile and cut it if it's left, but it doesn't even produce anything less than 6m long.

Therefore, in case of installing the pile instead of a ready-made product, a method of pouring concrete after pre-excavation with an auger drill is generally applied, but this has a disadvantage in that the bearing capacity cannot be determined without a load test. Moreover, when the pile length is different due to uneven ground conditions, it is equally unstable unless the load test is performed by length.

Auger drill is made of piles filled with concrete instead of soil removed in the process of drilling holes in the ground, but the part is composed of hardened piles, but the effect of increasing the frictional force due to the increase of ground density around piles cannot be expected. Therefore, it is safe to allow the pile to be supported by ignoring the frictional resistance of the pile and making it into the hard ground. However, when the hard ground is deep, the construction cost increases.

In addition, the soft ground has a disadvantage that the hole drilled by the auger drill easily collapses, and in order to prevent this from happening, the soil around the hole enters the casing in the process, and the auger drill is operated again. do.

Therefore, to obtain the effect of compacting the ground, while checking the bearing capacity during the pile driving, a cheap and easy in situ pile method to secure a large bearing capacity even in a short length is required.

1 is a cross-sectional view of the CFTTP 1.

2 is a plan view of the foundation using the CFTTP 1.

3 is a side view showing the penetration of the temporary pile 6 for the construction of the CFTTP (1).

4A is an elevation view of the penetration support band 10.

4B is a plan view of the penetration support band 10.

<Brief description of the symbols in the drawings>

1: Concrete Filled Thin Tube Pile--CFTTP

2: Thin Tube

3: Pedestal

4: base plate

5: pillar

6: Temporary Pile

7: Pile Shoe

8: Pile Head

10: penetration support band

11: Ω band

12: Filling bolt

13: Through Bolt

14: sleeve pipe

15: wings

A short support pipe (2) galvanized on the ground to be piled up is placed and the temporary pile (6) is inserted through the upper hole and the pile is hammered into the temporary pile (6). The tube 2 blocked by 10) is driven into the ground at the same time as the temporary pile 6, and when the temporary pile 6 is recovered, the hollow tube 2 remains in the ground.

In the process of driving the temporary pile (6) in spite of the penetration of all the tube (2), if the predetermined pile support force is not secured, continue piling in the state of removing the through bolt 13 of the penetration support band (10) CFTTP (1) is generated by injecting concrete into a hole formed by injecting only the temporary pile 6 to a predetermined depth while leaving the tube 2 in place.

However, if the depth of driving the temporary pile (6) is too deep to be a burden, draw the temporary pile (6) on the way, fill the concrete inside and chop the concrete into the temporary pile (6) from the bottom of the tube (2) In the furnace, concrete gathers and penetrates the soft ground to form a mandrel stand (3).

After the compaction, the empty space in the tube (2) is filled with concrete to complete the reinforced CFTTP (1).

If the bearing capacity of the pile is not secured in the process of driving the temporary pile (6), it is checked by load test whether the frictional resistance of the mandrel support (3) and the pile end bearing capacity increase due to the increased cross section satisfy the predetermined values.

The inner diameter of the tube 2 is about 250 mm and the length is 2-3 m so that the remaining length is cut off or beaten with a hammer while removing the temporary pile 6 to adjust the level.

Bend a thick iron plate in a semicircular shape slightly larger than the inner diameter of 250 mm, and bend both ends in an outward right angle to form a wing 15, and drill a hole for a 50 mm diameter through bolt (13) in the center of two Ω bands 11 and both wings (15) Penetration support band (10) is to drill two 9mm filling bolts (12) on each side to fill the filling bolts (12) facing each other on both sides of the thumb pile, and to fix the through bolts (13) through the sleeve pipe (14). .

The use of CFTTP (1) prevents waste from cutting off the off-the-shelf piles, and ensures the support of each pile in the process of driving the temporary piles (6), and it is reasonable to rely on the ground friction due to the deep hard soil depth. If it is determined that there is an effect that the bearing capacity is increased by forming the mandrel support (3) by the method of compacting the concrete into the temporary pile (6).

Claims (5)

A short pipe tube (2) galvanized on a soft ground is placed, and a temporary pile (6) having a penetration support band (10) is inserted into the upper hole, and the hammer is inserted into the temporary pile (6). CFTTP (1) and its method of filling In the process of driving the temporary pile (6) of claim 1, even if all the pipe 2 is intruded, if the predetermined pile support force is not secured, pile piling in the state of removing the through bolt 13 of the penetration support band 10 CFTTP (1) and the method of injecting concrete into the formed hole by injecting the temporary pile 6 to a predetermined depth while leaving the tube 2 in place. In claim 2, if the depth of driving the temporary pile (6) is too deep to draw the temporary pile (6) in the middle of the way and to fill the concrete inside and compact the concrete with the temporary pile (6) bottom of the tube (2) Reinforced CFTTP (1) that filled the empty space in the tube (2) created by the process of compaction by making the underlying concrete grab and penetrate the soft ground, and the construction method Weld conical support band by welding conical pile shoe (7) at the bottom of thick wall pipe and drilling sleeve at the proper position (6) where welded circular steel pile head (8). (10) Temporary piles (6) for inserting fixing bolts (13) Bend a thick steel plate in a semicircle and bend both ends in the outward right angle to form a wing (15). Penetration support band (10) for drilling holes to fill the filling bolt (12) facing the both sides of the thumb pile and fixed to the through bolt (13) through the sleeve pipe (14)