JP2002294684A - Improving method and device for ground under existing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device effective as a countermeasure against liquefaction for maintaining functions of an existing structure of which functions need to be constantly maintained. SOLUTION: A small diameter excavation hole is formed in a runway 2 on the ground 1 of an airfield (airport) where a compaction grouting Denver system is applied by means of an on-vehicle type boring machine 14. Next, a solidified and stacked body 41 of soil mortar of no fluidity and low slump is continuously fed under pressure to be laminated by an on-vehicle special pressure-feeding pump. Peripheral ground is compacted and hardened to be compressed and tightened for reducing gaps in the ground 1 for improving strength and rigidity. Generation of irregularities or liquefaction in the runway 2 by an earthquake such as a severe earthquake to cause trouble in aviation security facilities is thus prevented to achieve functions of the security facilities.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The disclosed technology takes measures such as prevention of liquefaction of the ground below existing structures, such as airfields (airports), highways and quays, which have a function of being used semi-permanently on a daily basis. It belongs to the technical field of ground improvement construction technology.

[0002]

2. Description of the Related Art As is well known, in Japan, where the land is narrow and there are many mountainous forests, and where there are special terrain conditions approaching a complicated and long coastline, homes, of course,
The effective use of flat lands for various corporate facilities is extremely important. It is not limited to the use of flat lands that have a relatively small area, but has been used for a long time since landfilling and dredging of rivers, lakes and marshes and shallow coasts. In recent years, ground improvement techniques have been proactively implemented, in which soft ground improvement works are actively carried out through the injection of improving materials such as cement and cement milk into the ground. However, in the ground improvement technology based on this kind of conventional technology, the improvement material injected into the ground runs away in the ground, strays, and contaminates the groundwater. There is a possibility that uniformity may be seen or a pollution problem may occur. In addition, in the case of a sand drain or a chemical pipe pile method, the embankment is filled on the upper part of the improved material filled in the ground, and furthermore, drainage is performed by a load on the ground. In addition, there is a problem that the construction accuracy is not uniform, and that the size of the construction machine is not suitable for the construction directly under the existing structure such as an airfield runway. Was.

[0003] In addition, Japan is one of the world's leading earthquake nations. In rare cases of severe earthquakes, the permeability of groundwater in soft ground, which has been improved by the above-mentioned conventional construction method, changes once, causing severe liquefaction. There is a disadvantage that a phenomenon occurs, and the meaning of the initial ground improvement is lost.

[0004] In particular, in a large-scale existing structure of a facility which is used semi-permanently in an ordinary daily life such as an airfield (airport), a highway, a quay, etc., the liquefaction phenomenon is functionally fatal. There was a risk of becoming.

[0005]

On the other hand, one of the applicants has a non-flowable, self-curing, low slump (0 to 0).
5cm etc.) is intermittently pressed into the ground, and a ground improvement method is devised to make a solid-structured laminated structure.
Gradually, the results have been good and the number of works has increased, and it has been widely used as a so-called compaction grouting Denver system.

[0006] The construction method of the compaction grouting Denver system is described in, for example, Japanese Patent Laid-Open No. 6-10844.
No. 9 (Japanese Patent No. 27432232), which has attracted great attention in the civil engineering industry.

[0007] In the above-mentioned permanent existing structures such as airfields (airports), highways and quays, even if the primary ground improvement method by sand or crushed stone is injected into the ground. When an earthquake such as a severe earthquake occurs with a small number of times over time,
Due to liquefaction phenomenon, uplift or subsidence, the existing structure is damaged to the extent that it cannot fulfill its original function, cannot be used and cannot be used. Repairing has the disadvantage that the number of construction steps such as repairing the re-asphalt coating increases and also has the disadvantage that the cost is extremely high.

Thus, the existing structure is important in its use as a permanent existing structure under the terrain conditions of Japan where the plain area where the national land can be effectively used is limited as described above, It goes without saying that its integrity is extremely remarkable.

[0009]

The object of the invention of this application is based on the above-mentioned prior art, which is based on the above-mentioned prior art, in the narrow country of Japan, which makes effective use of limited plains, and which has an existing semi-permanent permanent function. Technical issues to be solved such as loss of function due to liquefaction phenomenon etc. due to earthquakes etc. of the structure, and after improving the ground under the existing structure that was subjected to primary construction based on the conventional technology, In general or partly, the above compaction grouting denver system is used to perform solid ground improvement by stacking, so that even if liquefaction occurs, the function of existing structures will not be lost, and in the construction industry It is an object of the present invention to provide an excellent method for improving the ground of a lower part of an existing structure, which is advantageous in the field of application of the existing structure function retention technology, and an apparatus directly used in the method.

[0010]

SUMMARY OF THE INVENTION In accordance with the above-mentioned object, the construction of the invention of the present application, which has the scope of the above-mentioned claims, solves the above-mentioned problems by constructing a lower ground of an existing structure by a compaction grouting denver system. A method of improving the ground by performing a drilling of a small size and a predetermined diameter at predetermined intervals on the surface of the lower ground of the existing structure,
A non-flowable, self-curing, low-slump soil mortar is statically press-fitted into the drilled hole to form a block-shaped solidified stack in a laminated shape so as to compress and strengthen the surrounding ground, Drilling is performed on the ground below the existing structure at predetermined intervals, and the compaction grouting Denver system is constructed within the restrained time of the existing structure. In particular, the compaction grouting is performed on the runway of an airport (airport). To do it. In addition, in equipment that performs compaction grouting work on the ground below the existing structure, the boring machine is mounted on the unit UNIK, and the special pump on the vehicle is also mounted on the vehicle via the flexible hose, and the special pump is mounted on the special injection plant. The slime storage box may be provided as a pit in the boring machine, and the special pump may be selectively connected to a plurality of special plants in a predetermined manner. In addition, a technical measure is taken such that the lid is sealingly disposed at the hole drilling position by the boring machine.

[0011]

[Function] Ground improvement work based on the conventional technology for the semi-permanent existing structure, such as airfields (airports), highways and quays, which are scattered in the flat area where Japan can be effectively used in the narrow land area In general, if the liquefaction phenomenon occurs in the ground due to an earthquake such as a strong earthquake, attention should be paid to the lower ground of the existing structure in order to maintain the function of the existing structure and maintain it constantly. In order to carry out ground improvement work by the compaction grouting Denver system that has been carried out, a boring machine or the like equipped with on-board drilling holes with a diameter of 7 cm etc. at predetermined intervals on the surface of the lower part of the existing structure at regular intervals such as in the longitudinal direction Drilling, and for the drilling,
Non-flowable, self-curing and low slump (0-5c
m) is intermittently pressed into the ground using a special on-vehicle type pump, and the surrounding ground is compressed and strengthened by the press-fitting, causing a consolidation phenomenon, which may cause groundwater fluctuation. Actively in the ground so as not to increase the strength and rigidity of the ground under the existing structure,
The liquefaction phenomenon is reliably prevented, the function of the existing structure is sufficiently maintained, and the low-slump injection material is statically injected. By having no adverse effect on incidental structures such as communication facilities, and by performing nighttime construction work at airfields (airports),
The next morning, the facilities of the Denver system, such as boring machines and special pumps, were mounted on-board so that they could be set and reset mutually at the construction site so that the functions of the airfield (airport) could be restored again. In order not to be an obstacle.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. 1 to 11 as embodiments of the present invention.

The appearances of the various plants in the figures are not exactly the same because they are deformed.

In the embodiment shown in FIG. 1, FIG. 1 shows an embodiment of an airfield (airport) which is constantly used. A work yard 3 is provided, and a part of the work yard 3 is provided so that a fixed work plant 4 which is almost permanently installed does not hinder the construction of the compaction grouting denver system by installing the generator 5 behind. The stationary work plant 4 is provided with a hopper 6 ′ in which the press-fitting material 6 is used, and a special press-fitting plant 7 movable to a compaction grouting portion of the runway 2 is connected to a front portion thereof. A 4-ton unic truck-type boring machine plant 8 slides from the work yard 3 so that it can move and retreat in front of the UNIC of the special press-in plant 7. It is freely carried set and removed easily to 2.

In addition, an injection pipe injection rod lift device 9 is set together with a weight pressure monitoring device 10 at an intermediate portion of the boring plant 8 and the special press-fitting plant 7.

Next, each plant will be described in detail with reference to FIG. 2 and the following figures.
2 and the generator 13 and the boring machine 14 can be used freely. In the above-described configuration, the boring machine 14 can be drilled at predetermined intervals in the longitudinal direction of the runway 2 via the crane 15 with the help of an operator 16. ,
Set as required.

The boring machine 14 is provided with a slime collection box 17 having an injection rod hole 22 and a box 23 for setting a submersible pump water as shown in FIG. As shown in FIG. 4, a metal crown 24 and a stabilizer 25 to be drilled can be set at the front end of the runway 2 at a predetermined pitch in the longitudinal direction thereof.

As shown in FIG. 7, a special press-fitting pump 46 is selectively connected to a 20-ton Unic special press-fitting plant 7 by an injection mixing auger 45.

A schematic diagram of the arrangement per one drilling hole and the arrangement of workers will be described. A circulating hose, a water supply hose and a water supply pump from the generator 13 and the water supply pump 26 of the 4-ton unic 11 of the cap tire are explained. Are connected, and a special worker 16 and a normal worker 16 'are arranged.

The boring machine 14 is provided with a circulating submersible pump and a watering vehicle.

A vehicle 30 equipped with a boring machine 14 and a generator 13 is disposed on the opposite side of the cap tire.

Next, a special plant 7 for press-fitting compaction grouting is a 20-ton truck special denver system vehicle 33 with a water sprinkler and a rod washing station set on both sides. The vehicle 33 has a generator 13 'and a small-sized special Denver system. , Two special pumps connected and towed, worker 1
6 and 16 are arranged on both sides, and the caretaker is also arranged appropriately,
An operator 16 is also arranged and connected to the injection rod lifting devices 9,9.

The connection of the special press-fitting plant 46 to the pump 27 is continuously performed by the operator 16 through a selective operation using an injection mixing hose.

As shown in FIG. 10, a semi-trailer type 20-ton UNIC 35 includes a generator 13 ″ and a distribution board 36.
, A special plant 32 ', a cement silo 37,
8 is mounted by being raised.

As shown in FIGS. 3 and 4, the boring machine 14 is lowered from the 4-ton unic 11 to a predetermined hole in the runway 2 by a crane 15 and a worker 16, and the injection rod lift device is moved from a special press-fitting pump. When the mortar was pressed into the solidified pile 41,
From the cement silo 27 of the 0 ton Unic 35, the worker 1
6 connects a vent pipe (with an analog type pressure gauge) 48 to the injection rod 21, and presses the press-in material freely and repeatedly through the flexible hose 50 by continuously and repeatedly operating the special pump 46. The solidified stack 41 is pressed into the ground, the surrounding ground is compressed and tightened to reduce the porosity, thereby preventing the occurrence of the liquefaction phenomenon.

8 and 9, reference numeral 50 denotes a flexible hose, reference numeral 51 denotes an injection head having a tapered thread on the lower side, and reference numeral 52 denotes a clamp.

To make a hole in the runway 2, a hole having a diameter of about 10 cm is made in the runway 2 as shown in FIG. Is inserted and set, and the runway road surface protection cap 40 is covered with a concrete bond in preparation for an unexpected takeoff and landing of the working aircraft to complete the construction.

When the drilling is performed and the compaction grouting operation is once completed, the next drilling and compaction grouting are performed in a reversible manner and repeated.

The holes 22 are formed not only at regular intervals in the longitudinal direction of the runway 2 but also at predetermined intervals in the width direction.

At the time of starting work, the boring machine 14 and the special press-fit pumps 46 are mounted on the vehicle, so that they can move from the work plant 4 to the work site of the runway 2 quickly. After the completion of the construction, the removal to the predetermined site of the work preparation yard 3 is smoothly performed, and there is no obstacle to takeoff and landing of the aircraft.

In addition, as for the takeoff and landing of the aircraft during the work, the runway surface protection cap 40 is fixed to the upper part of the injection lot 21 as shown in FIG. Is maintained and does not cause any obstacles.

For compaction grouting, the compaction grouting denver system method disclosed in the above-mentioned Japanese Patent Application Laid-Open No. Hei 6-108449 (Japanese Patent No. 27432232) was directly performed, and the compacted piling was performed. The non-fluid, low slump (0-5 cm) solidified stack 41 (shown in FIGS. 1 and 8) filled by static indentation compresses and strengthens the ground around runway 2,
A special press-fit pump 4 is used to reduce the porosity of the ground and to press-fit the solidified pile without using a vibro hammer or the like.
6 is press-fitted through the flexible hose 50, so that it is extremely static, there is no vibration or noise to the surroundings, and there is no obstacle to peripheral facilities.

There is no influence of vibration or the like on the communication facility.

The slime is removed by the water supply shown in FIGS. 4 and 5 and is sufficiently collected in the slime storage box 17 and can be disposed of without pollution.

It should be noted that the embodiments of the invention of this application are not limited to the above-described embodiments, and may be applied to existing structures such as highways and large buildings. is there.

[0036]

As described above, according to the invention of the present application, a severe earthquake in a state where the air conditioner (airport) or the like of an existing structure, which is basically constantly operating, operates on a daily basis. If there is a risk of liquefaction of the foundation ground due to such earthquakes, statically press the solidified pile into the ground using the compaction grouting Denver system method that has been performed successfully until now. In order to consolidate and compact the surrounding ground, the porosity of the liquefied ground becomes low and the restoration phenomenon does not occur, and the function maintenance of the existing structure is surely achieved.

[0037]

As described above, according to the invention of this application, it is not possible to easily move the plant by mounting various plants on the lower ground of the existing structure by performing the liquefaction prevention function by the compaction grouting Denver system. A flexible working hose is connected to a mobile plant that can be set up in a preparatory work yard by moving a flexible working plant, and if the pavement is temporarily removed, temporary recovery can be performed by the next morning and security facilities, etc. An excellent effect can be achieved that can be easily avoided.

In addition, since the boring machine, the press-fit pump, and the like are mounted on a vehicle, the mobility is enhanced, and an excellent effect that the construction work can be reliably performed within a limited restraint time such as at night is exhibited.

When the compaction grouting denver system is constructed on the lower ground of the existing structure, a hole of 10 cm or the like is formed in the surface of the ground, so that when the surface hardness of the ground is high. In addition, in combination with the fact that the construction can be easily performed and the static construction without vibration noise, an excellent effect that can be performed as designed and responsively is exhibited.

Further, since the ground improvement for preventing the liquefaction phenomenon is performed by the compaction grouting plant method, there is an advantage that unexpected ground subsidence due to consolidation settlement can be performed using various facilities. .

When a boring machine is lowered from a 4-ton unic or a press-fit pump is lowered from a 20-ton unic, it is very easy to handle by an operator, work efficiency is high, and construction as designed can be performed reliably. This has the effect.

As described above, according to the invention of this application, a boring machine is basically used for performing compaction grouting work to prevent liquefaction of the lower ground of an existing structure, such as an airfield (airport), which functions constantly. By installing a special pump and a special pump, the ease of movement is enhanced, and an excellent effect is achieved in that the construction can be performed efficiently during a limited time period from night to early morning.

In each mobile plant,
In general, since the height can be limited because the size can be reduced to a small size, workability is remarkably improved, and an excellent effect that the point efficiency is extremely excellent is exhibited.

By making the plant on-vehicle, the effect of eliminating restrictions on the position of the work yard and not impairing the functions of security facilities and the like can be obtained.

[0045] Since the compaction grouting denver system is uniformly applied to each of the holes, there is also an effect that irregularities on the ground surface can be avoided.

Further, when the pavement or the like is temporarily removed, temporary recovery can be effected in a short time.

Also, since it can be buried in the upper part of the hole by the cap system for protecting the runway road surface, the airfield (airport)
There is also an advantage that unexpected takeoff / departure of the aircraft during the operation can be performed without any obstacle.

In addition, even when there is a possibility that a liquefaction phenomenon may occur due to an earthquake such as a strong earthquake, an excellent effect that its normal functions including peripheral facilities can be maintained.

[Brief description of the drawings]

The drawings show aspects of an airfield (airport) according to an embodiment of the present invention.

FIG. 1 is a sectional view of a general portion of an airfield (airport).

FIG. 2 is a side view of a vehicle-mounted 4-ton Unic equipped with a boring machine.

FIG. 3 is a side view of a state in which a boring machine is unloaded and set from a 4-ton unic.

FIG. 4 is a side view of a set boring machine connected to a water supply hose.

FIG. 5 is a schematic diagram of a slime storage box.

FIG. 6 is a view showing a mode of a set of a boring machine.

FIG. 7 is a plan view of a connection mode from a vehicle-mounted pump UNIC to a special pump.

FIG. 8 is a side view of a press-fitting mode of the solidified stack to the inner ground of the runway.

FIG. 9 is an exploded side view of an injection rod lift device and a solidified stack injection mode.

FIG. 10 is a side view of a UNIC of a special press-fit pump plant.

FIG. 11 is a sectional view of a runway road surface protection cap.

[Explanation of symbols]

 Existing structure 1 Ground 14 Boring machine 11 Unic 46 Special press-in pump 50 Flexible hose 17 Slime storage box 40 Lid

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[Procedure amendment]

[Submission date] April 5, 2001 (2001.4.5)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 3

FIG. 5

FIG. 4

FIG. 6

FIG. 7

FIG. 8

FIG. 9

FIG. 10

FIG. 11

 ──────────────────────────────────────────────────続 き Continued on the front page (71) Applicant 391019740 Sanshin Construction Industry Co., Ltd. 1-2-7 Koraku, Bunkyo-ku, Tokyo (72) Inventor Hisaki Kato 3-3-1 Haneda Airport, Ota-ku, Tokyo Country Ministry of Land, Infrastructure, Transport and Tourism Kanto Regional Development Bureau Tokyo Airport Construction Office (72) Inventor Nobuo Matsushita 3-3-1 Haneda Airport, Ota-ku, Tokyo Japan Ministry of Land, Infrastructure, Transport and Tourism Kanto Regional Maintenance Bureau Tokyo Airport Construction Office (72) Inventor Kitazume Masaki 3-1-1 Nagase, Yokosuka City, Kanagawa Prefecture Inside the Port and Harbor Research Laboratory, Ministry of Land, Infrastructure and Transport (72) Inventor Hiroyuki Yamazaki 3-1-1 Nagase, Nagase, Yokosuka City, Kanagawa Prefecture Inside the Port and Harbor Research Laboratory, Ministry of Land, Infrastructure, Transport and Tourism (72) Invention Person Yuzu Murasawa 2-31-1 Nihombashihamacho, Chuo-ku, Tokyo Mitsui Fudosan Construction Co., Ltd. (72) Inventor Takeshi Konishi Japan Chuo-ku, Tokyo 2-3-1 Hamacho Mitsui Real Estate Construction Co., Ltd. (72) Junichi Yamamoto Inventor 2-31-1 Nihonbashi Hamacho Chuo-ku, Tokyo Mitsui Real Estate Construction Co., Ltd. (72) Kazumi Osawa Koraku 1 Bunkyo-ku, Tokyo -2-7 Inside Sanshin Construction Industry Co., Ltd. (72) Inventor Masami Watanabe 1-2-7 Inside Sanshin Construction Industry Corporation (72) Inventor Toshiyuki Akiyama 1-Kuraku 1 Bunkyo-ku, Tokyo 2-7 Sanshin Construction Industry Co., Ltd. F-term (reference) 2D040 AA01 AA06 AB06 AB09 BA13 CA01 CD01

Claims (2)

[Claims] 1. A method for improving the ground by performing compaction grouting work on a lower ground of an existing structure. In the method, a hole having a predetermined diameter is formed at a predetermined interval in a surface portion of the ground of the existing structure. A low-slump, non-flowable, self-hardening soil mortar is statically pressed into the ground to form a solidified stack in a laminated form, and the surrounding ground is compressed and strengthened. A ground improvement method under the existing structure, wherein a ground improvement device suitable for performing the construction within the restraint time is used. 2. A special injection pump mounted on a vehicle is connected to a special injection plant via a flexible hose, a slime storage pit is provided on a boring machine, and the special pump is selectively connected to a plurality of special plants. A ground improvement device at the lower part of an existing structure, wherein a cap for protecting a runway road surface is provided at a drilling position by a boring machine.