JPS58528B2 - Pile sinking and consolidation equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for firmly installing cylindrical concrete piles in the soil.

Traditionally, cylindrical piles with open ends have been used with diesel hammers, vibrating type hammers, and in the case of resonant type hammers, which cause impact noises and vibrations that cause pollution. After digging a hole using a screw auger, etc., piles are installed, or while the piles are being installed, a medium excavation is performed, and the piles are sunk one after another.However, unlike driven piles, However, since the frictional force between the outer surface of the pile and the ground and the supporting force due to the driving into the supporting layer cannot be expected, if the hole is previously excavated with a screw auger, cement is added to the bottom of the hole before the pile is erected. After filling the milk and stirring it with the earth and sand at the bottom of the hole using a screw auger, insert the pile until the cement milk hardens, penetrate the bottom end of the pile into the cement milk, and as the cement hardens, the tip of the pile will be mixed with the cement milk. Although the cement milk and soil are mixed to increase the bearing capacity by bonding with the ground, it is not possible to increase the bearing capacity as much as a driven pile due to uneven mixing of the cement milk and soil.
In particular, the amount of initial settlement is significant and a large number of piles are required.
It is uneconomical.

Furthermore, the construction method itself is tedious and involves digging holes, pouring cement milk, and erecting piles.

Recently, a grout rod is inserted into a cylindrical pile built to a predetermined depth, and the grout rod is penetrated further into the ground below the cylindrical pile to penetrate into the ground near the tip of the cylindrical pile. announced a method to integrally connect the pile and the mixed area of grout and earth and sand by spraying grout material horizontally at high pressure, mixing the cloud material and earth and sand in an area larger than the outside diameter of the pile, and then solidifying the mixture. However, the digging or driving of holes for erecting piles and the injection of grouting material are performed in separate processes using completely different equipment, which is time-consuming, inefficient, and uneconomical.

The present invention provides a pile sinking and consolidation device that allows a series of operations from excavating pile holes, erecting piles, and injecting grouting material to be performed with one device without removing the auger. is the primary purpose.

The second purpose is to use a hollow shaft to pump drilling fluid at medium and low pressure, and to inject the drilling fluid from each drilling fluid injection nozzle, with the drilling fluid from the downward injection nozzle, First, a pilot hole with a relatively small diameter is drilled, and then the earth and sand below the lower end of the cylindrical pile is excavated to about the outer diameter of the pile by the drilling fluid injected from the horizontal injection nozzle, and then the soil is excavated by the auger head. The excavation is agitated to fluidize the earth and sand together with the excavation fluid, and the soil is removed from the top of the pile using earth removal blades attached to the outer circumferential surface of a rotating hollow shaft in a cylindrical pile, while being applied vertically to the pile. Once the load is applied and the concrete is sunk to the specified depth,
The injection of drilling fluid is stopped, and then using the hollow shaft, a grout material made of cement milk is injected horizontally at high pressure from the grout injection nozzle at the tip, forcing the earth and sand around the pilot hole and the grout material. The auger is mixed in the soil at the bottom of the cylindrical pile, and a cylindrical body with a diameter larger than the diameter of the cylindrical pile is poured into the soil at the bottom of the cylindrical pile. An object of the present invention is to provide a pile setting and consolidation device that can be used to consolidate and form piles.

In the present invention, a bit, a downward drilling fluid injection nozzle, and a horizontal grout injection nozzle are provided at the tip of the hollow shaft, and a predetermined space is provided between the downward drilling fluid injection nozzle and the horizontal grout injection nozzle. A valve body is installed to close the downward drilling fluid injection nozzle when pressure grout is injected, and an auger head is fixed around the hollow shaft at a position slightly above these nozzles. A horizontal drilling fluid injection nozzle that communicates with the gap between the hollow inner pipe inserted into the hollow shaft and the hollow shaft,
It is located close to the auger head, and the hollow shaft above these is equipped with earth removal blades (including screws) with a lead angle, and the upper end of the hollow shaft is movable relative to the machine frame. It is rotatable by a drive motor installed in the movable frame, and the upper end of the hollow shaft has a drilling fluid filling port that communicates with the gap between the hollow shaft and the hollow inner tube. The pile setting and consolidation apparatus is characterized in that a drilling fluid and grout filling port are provided which communicate with a fluid injection nozzle and a horizontal grout injection nozzle, respectively.

Next, the present invention will be explained based on typical embodiments shown in the drawings.

1st embodiment (see FIGS. 1 to 7) 10 is a hollow shaft, and a drilling fluid injection nozzle 11 is provided on the lower end surface, and a drilling bit 12 is provided around this shaft.
It is equipped with a removable device.

The drilling fluid injection nozzles 11 may face straight down, or two or three nozzles may be provided that are slightly inclined.

The inside of the drilling fluid injection nozzle 11 is a valve seat 13, and the valve body 14 closes against the force of a spring 15 when the internal fluid pressure exceeds a predetermined pressure. It is designed to open due to the repulsive force.

Reference numeral 16 designates a grout material injection nozzle that is provided through the peripheral wall slightly above the lower end of the hollow shaft 10, and is opened in the X′ horizontal direction. Set up at different heights.

An auger head 17 is fixed to the outer periphery of the hollow shaft 10 at a slightly upper position, and several digging bits 19 are fixed to each arm 18 extending in the radial direction.

On the outer periphery of the hollow shaft 10 above the auger head, a soil removal blade 20 with a lead angle is provided.In FIG. 1, it is a screw 20a, and in FIG.
The discontinuous blades 20b protrude in the radial direction of the soil and play the role of stirring and removing soil.

These radial dimensions are of the same order of magnitude as the radial dimensions of the auger head 17.

A hollow inner pipe 21 is inserted into the hollow shaft 10 located above the auger head with a slight gap, and the inside thereof communicates with the drilling fluid injection nozzle 11 and the grouting material injection nozzle 16. The gap 33 between the hollow shaft 10 a and the hollow inner tube 21 above the auger head does not communicate with the injection nozzles 11 and 16 , and a radial (horizontal) drilling fluid injection nozzle 22 is provided close to the auger head 17 . is connected to.

The upper part of the hollow shaft 10 is mounted on a leader 23 so as to be movable up and down, is rotatably supported on a movable frame 24, and is rotated by a motor 31 mounted on the movable frame 24.

The hollow shaft 10a and the hollow inner pipe 21 protruding from the upper end of the hollow shaft 10 are each equipped with a rotatable cap 25. Drilling fluid and grout filling ports leading into the interior of the pipe 21 are provided, and these filling ports are connected to the hose 2.
6.27 is connected to the hollow shaft 10a and the hollow inner tube 2.
A drilling fluid feeder 28 is connected to the hose 27 that communicates with the gap 33 between the hollow circular pipe 21, and a drilling fluid feeder 28 and a grout feeder 29 are connected to the hose 26 that communicates with the inside 32 of the hollow circular pipe 21. , are connected via a switching valve 30.

Second embodiment (see FIGS. 8 and 9) The same reference numerals as in the first embodiment indicate the same components.

The difference is that a hollow inner tube 21 is inserted from the upper end of the hollow shaft 10 up to the grout injection nozzle 16 portion, and therefore the grout injection nozzle 16 is different from the hollow shaft 10.
An air injection nozzle 34 is provided on the hollow shaft 10 near the nozzle 16 and communicates with the gap 33.

A common vertical slide valve 35 is provided on the inner surface of the air injection nozzle 34 and the drilling fluid injection nozzle 22 which is opened in the vicinity of the auger head.
There is a tsuba 36 with an area equivalent to 3, and the weight is approximately 100 kg.
/cm2 or less, it does not move, only the upper drilling fluid injection nozzle 22 is open and the air injection nozzle 34 is closed, and when the internal pressure exceeds about 100kg/cm2, the pressure causes the collar 36 to move downward. When pressed, the upper nozzle 22 is closed and the air injection nozzle 34 is opened.

Additionally, a grout injection nozzle 16 is provided at the upper end of the valve body 14.
A slide valve 14a that opens and closes the inner end of the valve body 14a is integrally attached to the slide valve 14a so that when the valve body 14 is in the upper position, the grout injection nozzle 16 is closed, and when it is in the lower position, it is opened. is equipped with.

The operation of the present invention constructed as described above will be explained below along with its pile sinking and consolidation method.

First, erect a cylindrical pile P to be erected on the ground surface, then insert the auger from the upper end of the pile, and with the bit 12 at the lower end of the hollow shaft 10 in contact with the ground, 5 kg of drilling fluid (usually water) is poured into the pile. When the drilling fluid is fed from both the hoses 26 and 27 at a pressure of about 100 kg/cm2 to 100 kg/cm2, the drilling fluid fed into the hollow inner pipe 21 reaches the hollow shaft 10 at the lower end of the auger head 17 and touches the valve seat 13. The drilling fluid passes through and is ejected as a downward jet from the drilling fluid nozzle 11, rotating the hollow shaft 10, sequentially drilling pilot holes, and lowering the entire auger.

Next, when the auger head 17 reaches the ground surface, the bit 19 of the auger head 17 expands the already wet shoulder of the pilot hole to the outer diameter of the auger head 17, mixes it with the drilling fluid, and turns it into a soft mud state. do.

As the excavation progresses, the drilling fluid injected from the hose 27 is injected from the drilling fluid injection nozzle 22 provided near the auger head 17, breaking up the earth and sand at the lower end of the pile P, and further reducing the diameter of the excavation hole to a diameter equivalent to the outer diameter of the pile P. The pile P sinks due to its own weight and the added load.

The light muddy soil is agitated by the auger head 17, passed through the pile P by the earth removal blades 20 above it, and is discharged to the outside from the upper end of the pile P.

In this way, the excavation is carried out sequentially and the piles P are deposited one after another until the bit 11 at the lower end of the hollow shaft 10 and the piles have sufficiently penetrated into the supporting layer, and then the injection of drilling fluid is stopped and the piles P
Then, using the hose 26, a grouting material such as cement milk is passed through the hollow inner tube 21 and applied to the lower end of the hollow shaft 10 at a weight of 100 kg/cm2 to 500 kg.
When press-fitting with a pressure of /cm2, this pressure causes the valve body 14 to
is pressed against the valve seat 13, the entire amount of grout is injected in a horizontal direction from the grout injection nozzle 16, the earth and sand in the support layer and the grout are mixed, and the entire device of the present invention is gradually lifted up. By turning the soil and grout mixture around the hollow shaft 10, a cylindrical body having a diameter considerably larger than the outer diameter of the pile P is formed from the mixture of earth and sand, and when the position of the nozzle 16 reaches the lower end of the pile P, , grout pressure 5
kg/cut to 50 &/cni, the valve body 14 separates from the valve seat 13 again, and the grout material flows through the nozzle 11.
Injecting the grout further downward and then pulling up the hollow shaft 10 a little further fills the inside of the lower end of the pile P with grout, and then stops the injection of grout, and rotates the hollow shaft 10 in the opposite direction to the direction of excavation. Remove it from the pile P while doing so.

In the device of the second embodiment, when the grout material is fed into the hollow circular pipe 21 under high pressure, the valve element 14 descends due to the pressure, closes the valve seat 13, and closes the grout material injection nozzle 16. The slide valve 14a, which had been closed, opens and the grout is injected from the nozzle 16.

At this time, when air is forced into the upper end of the gap 33 at a medium-high pressure, the air injection nozzle 34 opens, and both the grout and air are injected in the same direction, and these jets agitate the earth and sand around the pilot hole together with the grout. , In the same manner as above, the piles are deposited and consolidated.

The pile sinking and consolidation device according to the present invention configured and operated as described above has the following effects.

In the present invention, a bit 12, a downward drilling fluid injection nozzle 11, and a horizontal grouting material injection nozzle 16 are provided at the lower end of the hollow shaft 10, and these nozzles 11
, auger head 1 around the hollow shaft located slightly above 16.
A horizontal drilling fluid injection nozzle 22 is provided close to the auger head 17 and communicates with the gap between the hollow inner pipe 21 inserted into the hollow shaft 10 located above the auger head 17 and the hollow shaft 10a. Since the hollow shaft 10a above these is equipped with earth removal blades (including screws) 20 with a lead angle, in the medium excavation process of pile sinking work, first, the pilot hole with a relatively small diameter is drilled downward. The injection of drilling fluid from the drilling fluid injection nozzle 11 and drilling by the bit 12 and then the auger head 17
The diameter of the hole is further enlarged by the drilling fluid injection nozzle 22 in the horizontal direction, and the diameter of the hole is expanded to a portion corresponding to the outer diameter of the pile P. It becomes easy to remove soil through the inside of the pile P, and there is no fear that the pile P will be destroyed due to internal pressure due to being compacted inside the pile P as in the past, and the excavation can be performed by horizontally injecting the excavation fluid from the horizontal drilling fluid injection nozzle 22. The hole diameter can be expanded to a portion corresponding to the outer diameter of the pile P by the pressure of the fluid, and the pile P can be easily and quietly settled up to this portion.

Using the hollow shaft 10 of the auger for excavation (including the hollow inner pipe provided therein), the cement milk grout is applied to the grout injection nozzle 1 near the bit 12.
By simply changing the injection fluid between digging and grouting, the auger can be used as is, and the grout can be injected very efficiently following digging. Ru.

Furthermore, in the case of medium excavation, the lower end surface of the pile P can be easily excavated due to the pressure of the drilling fluid and the cooperative action of the auger. There is no need to use any equipment, the structure can be simplified, and the pile can be set with low noise while exhibiting the same pile support capacity as conventional methods.

An experimental example of the above noise effect is shown in FIG. 10 in comparison with a conventional example.

From this figure, when the noise is measured at a distance of 30 meters from the sound source, it is approximately 70 horns when this device is used, approximately 100 horns when using a conventional diesel hammer striking device, and 85 horns when this device is used. Conforms to the Noise Control Law, which has a regulation value of 75 horns, and the Tokyo Metropolitan Ordinance, which has a regulation value of 75 horns.

In addition, the injection and injection of grouting material was carried out at 100km in the horizontal direction.
When carrying out the process under high pressure of g/cm2 to 500 kg/cm2, the earth and sand in the supporting layer are mixed very uniformly, and a cylindrical body with a diameter considerably larger than the outer diameter of the pile P is formed at the lower end of the pile P. It has a strong bonding effect.

In particular, in the ground where the grout is injected, only a small pilot hole with a diameter small enough to insert the hollow shaft 10 below the auger head 17 is drilled, and the ground around it is not disturbed at all by the auger head 17. Since the ground is dense, it becomes denser due to the compaction of the grout material, and once the earth and sand in this area and the grout material are mixed, even before the grout hardens, the two will hardly be mixed due to the difference in specific gravity. By using this device, a strong improved ground is formed without separation, or the integration with the supporting layer is made strong, and the initial settlement of the pile P after the grout hardens and the pile P with very little settlement over time are constructed using this device. It is possible.

Furthermore, the injection pressure of drilling fluid is 5kg/cm2 to 100k.
g/cm2, it is particularly effective for excavating in clay layers and sand layers, and even in gravel-containing layers, it is possible to efficiently excavate the pilot hole and under the lower end surface of the pile P.

Also, the injection pressure of grouting material is 100kg/cm2 to 50kg/cm2.
Since the pressure is as high as 0kg/cm2, there is no auger head at all.
Even if the ground is not stirred in step 7, it is possible to sufficiently mix the soil and grout from the ground, and the pile P
It is possible to reach and mix the grout material to a range considerably thicker than the diameter of the pile, and it has the effect of forming a cylindrical improved ground that is thicker than the outside diameter of the pile.

Technically speaking, the injection pressure of grout material is 1000kg/c.
It can be increased to about m3.

In this case, the diameter of the grout mixing range will be approximately 3 to 5 m.

In addition, if water is used as the drilling fluid, it is inexpensive, and even if it is used once, it can settle mud and be reused. If the drilling fluid is air,
During excavation, it is possible to prevent contamination of the surrounding area by muddy water by removing excess water during excavation, and when it floats in the form of bubbles in the muddy water, it has the effect of assisting the drainage of earth and sand.

As in the device of the second embodiment, when the grout material is injected from the nozzle 16, air is simultaneously injected in the same direction at medium-high pressure from the air injection nozzle 34 provided in the vicinity, which improves the agitation effect of the earth and sand and improves the grouting effect. The reach of the grout material can be significantly improved, and the diameter of the ground mixed with grout can be approximately 1.5 to 3 times larger than when air injection is not used in conjunction with grout injection. Valve 1414a operated by drilling fluid pressure or pneumatic pressure
Since the slide valve 35 is provided, the location of the fluid to be injected can be selected by adjusting the internal pressure, and the fluid can be effectively injected where it is needed.

[Brief explanation of the drawing]

The figures relate to the present invention, and FIGS. 1 to 7 relate to a typical embodiment of the device. FIG. 1 is a schematic side view of the device of the present invention attached to a reader; Second
The figure is a schematic side view of an auger of another shape, Figure 3 is a vertical cross-sectional side view with the lower part of the auger partially cut out, and Figure 4 is a vertical side view of a medium-cut pile being pressed in using this device. Fig. 5 is a vertical side view after the pile has been sunk, Fig. 6 is a longitudinal side view during the injection of grout, and Fig. 8 is a part of the auger in the device of the second embodiment, showing a part during excavation. Fig. 9 is a partial longitudinal side view of the auger shown in Fig. 8 during grout injection;
FIG. 10 is a graph showing the results of a noise experiment. Symbols in the figure, 10...Hollow shaft, 11...Drilling fluid injection nozzle, 12...Bit, 13...Valve seat, 14...Valve body,
15... Spring, 16... Grout material injection nozzle, 17
... Auger head, 18 ... Arm, 19 ... Cutting blade, 20
... Earth removal blade, 21 ... Hollow inner pipe, 22 ... Excavation fluid injection nozzle, 24 ... Movable machine frame, 31 ... Motor.

Claims (1)

[Claims] 1. A bit, a downward drilling fluid injection nozzle, and a horizontal grout injection nozzle are provided at the tip of the hollow shaft, and between the downward drilling fluid injection nozzle and the horizontal grout injection nozzle, there is a grout at a predetermined pressure. A valve body is installed to close the downward drilling fluid injection nozzle during material injection, and an auger head is fixed around the hollow shaft located slightly above these nozzles. A horizontal drilling fluid injection nozzle that communicates with the gap between the hollow inner tube inserted into the auger head and the hollow shaft is installed at a position close to the auger head. ), and the upper end of the hollow shaft is rotatable with respect to the machine frame by a drive motor installed on the movable machine frame. The upper end of the hollow tube is provided with drilling fluid and grouting material filling ports that communicate with the downward drilling fluid injection nozzle and the horizontal grouting material injection nozzle at the tip of the hollow shaft, respectively. Features of pile sinking and consolidation equipment.