KR100750640B1 - Gravel compaction pilling method reform ground and apparatus thereof - Google Patents

Abstract

A sand and gravel compaction pile method for ground improvement is provided to form a compaction pile in the earth regardless of the property and condition of stratums by oscillating a vibrating pipe vertically and spraying water jet in the earth to form a perforation, placing filler in the perforation and compacting the filler. The sand and gravel compaction pile method for ground improvement comprises the steps of: installing a hopper(H) on a construction site and installing a vibrating pipe(4) equipped with many vibrating wings(8) vertically on the surface of the earth; perforating the surface of the earth by supplying pressure water to a vibrating pipe and a non-freezing pipe(12) through water supply pipes, oscillating the vibrating pipe vertically from the center of the non-freezing pipe using a vibration hammer and jetting out water jet(W), and inserting the non-freezing pipe to the earth; placing filler such as sand, gravel, etc. through the hopper; and oscillating the vibrating pipe vertically and pulling up gradually, and then compacting the filler to form a compaction pile in the earth.

Description

Sand compaction compaction pile method for soil improvement and suitable device {gravel compaction pilling method reform ground and apparatus

1 is a schematic view showing the configuration of a compaction pile device suitable for the method of the present invention.

FIG. 2 is an enlarged cross-sectional view showing the main part configuration of FIG. 1. FIG.

FIG. 3 is a partially extracted perspective view showing a lower configuration of the vibrating tube shown in FIG. 2. FIG.

Figure 4 is a process chart showing an example of sand gravel compaction construction by the device of the present invention.

Figure 5 is a side cross-sectional view showing another embodiment related to the apparatus of the present invention.

<Description of the symbols for the main parts of the drawings>

4: vibrating tube 6: vibratory hammer

8: vibrating wing 10: appendix

12: floating tube 14, 16: water pipe

18. 20: Watering fitting 22, 24: Sprayer

26: stopper 28: cap

Republic of Korea Patent No. 343419, Republic of Korea Patent No. 421540

The present invention relates to a method for improving sand gravel compaction pile and a device suitable therefor, in particular, by constructing sand or gravel piles in the ground of loose sandy ground or soft viscous soil in a lattice structure at regular intervals. The present invention relates to an improved sand gravel compaction method and a suitable device for improving the bearing capacity and reducing the amount of settlement by improving the shape to a composite ground and at the same time suppressing the liquefaction of the sandy ground during an earthquake.

As a method of reinforcing soft ground such as sandy soil, soft silt, and viscous soil layer, the casing is inserted into the ground vertically to a certain depth and excavated, and then a predetermined amount of sand gravel is introduced through a hopper, and the casing is compacted with a vibratory hammer. To the ground by a predetermined length, crushed stone, sand, etc., and repeat the process of compacting with a vibratory hammer to make the compaction pile in the ground. Direct power compaction method to remove the surface of the H pile from the ground by inserting sand gravel through the H pile and then compacting it into compaction piles. Type this myriad of perforated iron plates in the ground with a vibratory hammer For example, the Mueller-type column resonance method (also known as MRC method) is known, which makes the surrounding ground of the iron plate resonant and tightly compacted. Vibro-protrusion techniques are known that apply a horizontal vibration to compact.

In the above-mentioned Vibro Compressor method or direct power compaction method, the casing or H file should be introduced into the ground prior to the ground compaction. Therefore, the required process is long, the construction period is long and cumbersome, and the construction cost is high. In addition to the problem, in particular, the sandy soil layer is effective, but in the soil of the viscous soil has been evaluated to have the disadvantage of disturbing and weakening the surrounding ground.

In addition, casings or H-beams generate a large friction when penetrated into the ground, and contain a lot of wasteful power of construction.

In addition, the Muller type column resonance method of vibrating steel plate type on the ground has the advantage of easy construction, but it is only a method of mixing sand and gravel in the ground, and does not form a compaction pile, so improvement effect to solid ground is expected. It can't be done.

On the other hand, the Vibro projection method is a method that does not need to type a casing or H file in the ground, there is an advantage to fundamentally solve the above problems.

However, in the case of a dense viscous soil layer mixed with gravel at the construction site, it cannot be excavated by a water jet.

Loose sand layer below the groundwater level is required to improve the ground because it acts to promote the collapse by liquefaction in the event of an earthquake, the problem of the loose sand layer can be solved by increasing the density by compaction.

In the case of soft clay layers, loose sandy soils, or grounds in which these layers are alternately distributed, the compacted sand piles compacted in the ground are constructed in a lattice at regular intervals, and the bearings are improved by the composite ground. In addition, it is expected to reduce the settlement, stabilize the excavation slope, and suppress the lateral deformation.

The compaction pile method for such ground improvement should meet the following requirements.

First, even if a solid viscous soil or dense sandy soil layer is mixed in the middle strata of the construction site, it must be easily penetrated.

Second, the excavation and destruction of the surrounding ground should not occur even in construction in viscous soil layer by excluding the use of casing or H pile.

Third, in consideration of the general characteristics of the strata formed in a multi-layered structure and having local differences in density and hardness, it should be possible to construct a compacted pile that has been changed to a pile diameter corresponding to the density and hardness of the strata.

Since the bearing capacity of the compaction pile is related to the restraint pressure of the ground around the pile, if the pile diameter can be changed during construction, it can be improved to a homogeneous composite ground by constructing the compacted pile with a larger diameter in the relatively weaker ground. have.

The present invention synthesizes and considers all the problems seen in the conventional ground improvement sand gravel compaction pile method described above, and provides a ground improvement sand gravel compaction pile method and a device suitable therefor that can fundamentally solve them. There is this.

The compaction pile method of the present invention for realizing the above-mentioned object is a ground improvement sand gravel compaction method for drilling the ground vertically and inserting fillers such as sand gravel and then vibrating with a vibration hammer to compact the compaction pile. In this case, the vibration tube and the floating tube are vertically disposed on the surface of the tube and supplied with pressure water to each tube so that the water jet is ejected through the lower end thereof. When the oscillating up and down in the center of the floating tube is punctured to the depth of water by the water jet ejected from the appendix of the lower part, and can also penetrate the dense gravel layer contained in the strata by the vibration through the appendix, The water jet is ejected through the bottom of the water filled in the perforations in addition to the water jet of the vibrating tube Be around half the perforated portion held in the original position state, and to be as early as the drilling plan additional field added a filler, such as gravel sand in the bores to form a stake compaction the vibration tube in the ground as while pulling up and down vibration.

Moreover, the apparatus of this invention suitable for the above-mentioned method is equipped with the normal vibratory hammer, The hollow vibrating tube body which is vibrated up and down by this vibratory hammer, and the pressure water is supplied inside through a water supply fitting, and the inside of this vibrating tube body The appendages attached to the lower end of the vibrating tube so as to eject the number of pressure supplied to the water jet through a central spraying hole, and are arranged concentrically on a part of the outer periphery of the vibrating tube, and vibrates the vibrating tube up and down And a plurality of radially disposed at a predetermined position on the outer periphery of the vibrating tube surrounded by the floating tube, and a floating tube which ejects the pressure water supplied through the water supply fitting into the water jet at the bottom of the water hole. A stopper defining a lower moving position of the vibrating tube with respect to the vibrating tube, It is at the outer periphery radially arranged on the upper side of the appendix consists of a vibrating blade that defines the upper moving position of the oscillating tube for the floating tube.

In the apparatus of the present invention described above, a cap having a larger diameter can be detachably installed on the outer side of the appendix integrally attached to the lower end of the vibrating tube, and the cap has a diameter larger than that of the appendix. This is useful if you do.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments according to the accompanying drawings.

Figure 1 is a schematic view of the compaction pile device for implementing the sand gravel compaction pile method of the present invention, the compaction pile device is a vibration tube (4), which is installed in the field and installed vertically by a conventional crane (2), the vibration tube It becomes the structure provided with the normal vibration hammer 6 arrange | positioned at the upper end of (4).

The vibrating tube 4 has a plurality of vibrating blades 8 arranged radially on the outer circumferential surface of the lower side, and at the same time, the appendage 10 is fitted to the lower end to be integrally fixed.

On the other hand, the floating tubular body 12 is superposedly arrange | positioned at the outer periphery predetermined position of the said vibration tube 4, and is installed in a double tube type.

These vibrating pipe bodies 4 and the floating pipe bodies 12 are provided with water supply fittings 18 and 20 connected to external water supply pipes 14 and 16, respectively, as shown in FIG. The inside of the vibrating tube 4 connected to 18 is a passage of the pressure water communicating with the central side watering hole 22 of the appended water 10 attached to the lower end, and the floating tube connected to the water supply fitting 20 ( The inside of 12) is provided to the passage of the pressure water in communication with the sprinkling hole 24 which is drilled at the lower end is to eject the water jet, respectively.

In practice, the water injection jetted into the sprinkling hole 22 of the water injection 10 allows the water injection 10 to penetrate to the planned depth, and the water jet that is ejected from the floating tube 12 is in the underground space. Water pressure is added to the water jet of the vibrating tube 4 so that the periphery of the perforated ground is maintained in its original position, thereby preventing the ground from collapsing. It insulates and prevents the ground friction force and the adhesive force generated during the drilling of the ground from being applied to the vibrating tube 4 so that the up and down vibration of the vibrating tube 4 is consumed only in the ground drilling without loss.

In addition, even if a dense gravel layer exists in the strata, the water jet sprayed through the spraying holes 22 makes the soil mixed with the gravel layer suspended and separated from the gravel. The up and down vibration of the appendix 10 dissociates the gravel, so the appendix 10 can easily penetrate the dense gravel layer, and thus can be easily drilled to the planned depth.

A stopper 26 is attached to a predetermined position of a portion overlapping with the floating tube 12 on the outer circumferential surface of the vibrating tube 4, and the vibration tube 4 slides on the inner wall of the floating tube 12. When you define the limit of the downward movement position.

On the contrary, the limit of the upward movement position of the vibrating tube 4 is defined by the vibrating blade 8.

The stopper 26 has a structure arranged radially on the outer periphery of the vibrating tube 4 so as not to block a passage of the pressure water supplied to the floating tube 12 through the water supply pipe 16.

The appendix 10 has a funnel-shaped appearance, and the radius thereof is preferably set to a diameter close to the arrangement radius of the vibrating blade 8.

As shown in Fig. 3, the vibrating blade 8 disposed radially on the lower side of the vibrating tube 4 has an angle α of the upper hypotenuse 8a at an acute angle of about 30 degrees, and the lower hypotenuse 8b is 45 degrees or It is formed at an obtuse angle more than that.

The reason for setting the upper and lower hypotenuses 8a and 8b of the oscillating wing 8 at different angles is that the oscillating wing 8 when the oscillating tube 4 vibrates up and down to perform the compacting action of the sand gravel in the ground. The upper hypotenuse 8a formed at an acute angle in the process of rising in the sand gravel acts to receive a small resistance. Gives birth to the effect that it works efficiently.

Fig. 4 is a process diagram showing an example of sand gravel compaction pile construction by the apparatus of the present invention, in which a hopper (H) of a suitable shape is installed at a construction point, and is viewed on the surface of its center using a crane (2). The device of the invention is arranged vertically and then constructed.

Initially, when the oscillation hammer 6 is operated by supplying pressure water to the vibrating tube 4 and the floating tube 12 through the water supply pipes 14 and 16, the floating tube 12 is initially opened. When the vibration tube 4 is stopped at the ground surface and the oscillation tube 4 vibrates up and down, puncturing is started with a water jet, and when the vibration tube 4 oscillates up and down, the stopper 26 may contact the inner lower end of the floating tube 12. Each time the floating tube 12 also receives a load and gradually penetrates into the ground at the surface.

As described above, the vibrating tube 4 jets the water jet W through the sprinkling hole 22 of the appendage 10 to vertically puncture the surface.

Most soft ground can be perforated with water jets, but hard viscous or dense sandy soils cannot be perforated with water jets alone.

In the present invention, the solid viscous soil layer or the dense sandy soil layer can penetrate by breaking up a small stone lump or hard clay mass mixed in the strata by the vertical vibration of the appendix 10 added to the puncturing action by the water jet.

During this drilling process, the water jet ejected through the sprinkling hole 24 of the floating tube 12 supplies water pressure to the perforated space until the sand gravel is formed as a compaction pile, thereby maintaining the ground around the perforation part. Therefore, the frictional force and the adhesion of the ground do not act on the vibrating tube 4 at the center thereof.

When the infiltration of the appendage 10 is made by the vertical depth of the vibrating tube 4 as described above by the planned depth, the filler F such as sand gravel is introduced through the hopper H disposed on the surface, and the vibrating tube 4 ) Is slowly pulled up and down while compacting the filler (F). At this time, the water jet through the floating tube 12 is continuously supplied so that the vibrating tube 4 is inserted into the compacted filler F, so that resistance is not received at the time of drawing.

Compaction of the filling material (F) is carried out by pulling up the vibrating tube (4) at a slow speed up and down while vibrating the filling tube (F) in an appropriate amount, or slowly rotating the vibrating tube (4) to a certain height Crushing while pulling up, stopping for a while and putting a predetermined amount of filler (F), and then proceeding to chop up while slowly pulling up the vibrating tube (4), in any way the filler (F) in the ground It can be formed into a compaction pile.

On the other hand, in the method of the present invention, since the vibrating tube 4 is supported at the center of the floating tube 12 so that the vibration tube 4 is insulated from the ground, the vibration load generated from the vibratory hammer 6 is entirely lost without losing the vibrating tube 4. There is a characteristic added to). For this reason, it is also possible to detect the fragility of the strata by the change of the current value consumed for the operation of the vibration hammer 6.

That is, if the current value consumed by the vibration hammer 6 is higher than normal, the fragility of the strata is low and can be determined as a solid strata. On the contrary, if the current value is low, it can be determined as a strata with a high degree of softness.

Therefore, on the basis of this, the upper and lower vibration widths of the vibrating tube 4 are shortened and the construction is performed with a perforation having an expanded diameter. On the contrary, in the lower soft layers, the vertical vibration width of the vibrating tube 4 is increased. It is possible to construct compaction piles with the same bearing capacity for each depth by varying the diameter of the narrowed excavated tunnel.

The present invention described above has a structure in which the floating tube body 12 is disposed in duplicate on the outer circumference of the vibrating tube 4 and the vibrating tube 4 vibrates up and down, so that there is no friction between the inner periphery of the perforated surface and the vibrating tube 4, Therefore, the vibration energy of the vibration hammer 6 is transmitted to the appendage 10 of the tip with little loss.

In the drawings for explaining an embodiment of the present invention, the vibrating blades 8 are shown for example, arranged in a row in the axial direction for convenience, but may be arranged in two or three rows depending on the diameter and depth of the tunnel.

The diameter of the compaction pile formed in the ground by the present invention is correlated with the arrangement radius of the vibrating blade 8 and the arrangement number and the diameter of the appendage 10.

For example, a perforation having a diameter in the range of 400 to 600 mm can be easily installed by setting the diameters of the vacuum blade 8 and the appendage 10, and a larger range of 800 to 1000 mm corresponds to a vibrating wing 8 having a size corresponding thereto. And replace with the appendage 10, or may be installed and installed a removable cap 28 having a larger diameter to the lower side of the appendage 10 as shown in FIG.

The present invention as described above is to perforate into the ground by the jet of the water jet through the lower end simultaneously with the up and down vibration of the vibrating tube, so that the soil constituting the strata by the water jet becomes a suspension, Since the up and down vibrations act, it is possible to easily penetrate through the solid viscous soil layer or dense sandy soil layer, there is an advantage that can form a compaction pile in the ground regardless of the nature of the layer.

In particular, when the construction site is sandy soil, the density of compacted piles and the surrounding ground is increased, and this underground structure becomes a dissipation path for excess pore water pressure during the earthquake to prevent liquefaction. Will be.

In the case of the viscous soil layer, the compaction pile acts as a pile that transfers the upper load to the lower side, and the dispersion effect of the upper load can be expected, and the role of sand drain and improvement of the composite ground can be expected.

The method of the present invention has the following uses, that is, compaction to prevent liquefaction of loose sand layers, compaction of soft soils, improvement of composite soils for improving the bearing strength of viscous soil layers, and the role of sand drain in the ground layers, excavation slope This method is particularly suitable for improvement of suppression of arc activity destruction, suppression of lateral deformation of soft viscous soil layer.

Claims (3)

In the ground improvement sand gravel compaction method, in which a filler such as sand gravel is inserted into a tunnel which is perforated perpendicularly to the ground, and the filler is vibrated with a vibratory hammer to be compacted with a compaction pile. The vibration body and the floating body are vertically disposed on the surface of the ground vertically and the oscillating body is oscillated up and down at the center of the floating body with a conventional vibration hammer while the water jet is ejected to the bottom thereof to form a perforated part and the floating part. The water jet is also ejected to the lower end of the tube to allow the ground around the perforated portion formed by the vibrating tube to be drilled to a predetermined depth while maintaining the original position, and then a normal filler is put into the perforated portion and the vibrating tube 4 Sand gravel compaction pile method for improving the ground, characterized in that to form while the compaction pile is compacted into the ground while pulling up and down. Conventional vibratory hammers; A hollow vibrating tube vibrated up and down by the vibrating hammer and supplied with pressure water through the water supply fitting; An appendage having an outer diameter attached to a lower end of the vibrating tube and ejecting the pressure water supplied through the water jet from a central sprayer to a water jet to form a perforation in the ground and define the diameter of the perforation; A floating tube for supporting the vibrating tube to be vibrated up and down and insulated between the vibrating tube and the perforated part by ejecting the pressure water supplied through the water supply fitting into the water jet at the lower sprayer; A stopper disposed radially in a position surrounded by the floating tube at an outer circumference of the vibrating tube to define a lower movement position of the vibrating tube relative to the floating tube; A vibrating blade arranged radially on an upper side of the appendix to define an upward movement position of the vibrating tube with respect to the floating tube, and to squeeze the filling material injected into the punching portion with the compaction pile by piggybacking up and down of the vibrating tube; Sand gravel compaction pile device for ground improvement consisting of. The method according to claim 2, Sand gravel compaction pile device for ground improvement, characterized in that the cap having a larger diameter is detachably installed on the outside of the appendix integrally attached to the lower end of the vibrating tube.

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