JP2743232B2 - Ground improvement method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The field of the disclosed technology is the field of construction technology for improving soft ground or for facilities built in a predetermined ground area, or for improving ground to restore deformation such as uneven settlement or inclination of the ground surface. Belongs to.

[0002]

2. Description of the Related Art As is well known, in Japan, the effective use of flat terrain and the like is extremely important, and various researches on so-called soft ground improvement technology are not limited to utilization of existing plain areas. It has been developed for practical use.

[0003] However, grounds and the like artificially developed from such soft grounds and the like often cause uneven settlement and liquefaction, which often causes problems such as inclination and unevenness of the ground surface layer.

[0004] Further, such a phenomenon may occur even in a normal ground due to an increase in the weight of ground equipment and occupation of a large area.

[0005] To cope with this, various techniques for increasing the strength of the ground, including work for improving the soft ground, have been variously studied and put to practical use.

In order to reinforce the ground properties, a predetermined area of the ground has been drilled at a set pitch for a long time, and a predetermined solidified material or solidified material has been filled and pressed into the drilled hole. ,
Strength is enhanced through hardening of the ground through self-hardening action of these materials or solidification by chemical reaction with groundwater.

However, when the ground is improved by injecting and filling the consolidated material, it is necessary to be able to quantitatively inject the injected material. After the indentation, the material components are not separated in the indented region.
It is strongly required to maintain a uniform component and to compress the surrounding ground.

However, ordinary materials to be press-filled do not have such properties.

That is, in order to improve the operation efficiency of a press-fitting pump for improving the quantitative filling property into the ground, the slurry concentration of the solidified material or the solidified material is low and high fluidity is required. Highly consolidated and solidified materials decompose due to chemical instability over time after being pressed into the ground and filled,
It may separate or run away or stray in the ground, which may result in non-uniform components or pollution problems such as groundwater pollution that has recently been close-up. However, the compression action on the surrounding ground was also small.

[0010] Such a problem is not only in the soft ground improvement but also in the repair work such as ground restoration due to uneven settlement or deformation of the ground due to liquefaction of the ground.

[0011]

In order to cope with this, recently, a so-called compaction grouting method has been studied, but in the compaction grouting,
For example, in soft ground improvement work as shown in FIG.
Insert the press-fitting pipe 4 into the drilled hole formed from the surface layer 1, 2 to the middle layer 3 'and mix the cement, sand, and gravels, etc. of the solidifying material in a predetermined amount of water in a bottom-up (or top-down) manner. The non-flowable, self-hardening consolidation material 5 having a low slump (0 to 6 cm, etc.) close to 0 is bonded to each other in a block shape through a predetermined number of stages and stacked and filled. The surrounding ground is compressed through self-hardening over time, avoiding runaway or straying of the low-slump consolidated material 5, avoiding groundwater contamination, etc., and components that do not cause separation, etc. There is a demand for a technique that has advantages such as early consolidation and improved construction accuracy over time resulting from stability.

Further, as shown in FIG. 4, the press-fitting pipes 4 reach the support layer 3 '' with respect to the bases 3 'under the grounds 1 and 2 of the surface layer 1', and the top-down system Alternatively, a stack of predetermined low-slump, non-fluid, self-hardening consolidation material blocks 5 formed by a bottom-up method is interconnected by steps of predetermined stages to compress the surrounding soft ground 3 '. There is also an idea of performing a predetermined ground improvement for consolidating with time and horizontal restoration of the surface layer 1 '.

As shown in FIGS. 5 and 6, the non-flowable self-hardening block 5 of the self-hardening material has no dispersibility or fluidity and has shape retention properties. Utilizing the fact that the compressibility of the ground is good,
It is theoretically possible to repair or reinforce the liquefaction or uneven settlement so as to stably maintain the function of the structure 6.

However, the efficient practical use of such a so-called compaction grouting technique is based on the premise that the non-flowable self-hardening consolidated material is injected into the ground 3, 3 'from a ground plant. Pumping has been a bottleneck due to its non-flowability.

[0015] For the press-fitting of the solidified material into the ground, it takes time to transport the solidified material adjusted and manufactured by a plant installed at a long distance from the construction site to the site, and the solidified material with time Although there is a risk that the material may be damaged or deteriorated, it is desirable to procure, mix, and agitate solidified materials such as cement, sand, and gravel at the momentum construction site. There was a drawback that construction using locally procured materials was impossible because of the optimum slump and self-curing properties that matched the characteristics of the mountains 3 and 3 '.

[0016]

SUMMARY OF THE INVENTION The object of the invention of this application is to provide a low slump for compaction grouting based on the prior art described above.
It is a technical issue to solve the problems of practical application of improvement, such as soft ground improvement using a non-flowable, self-hardening consolidated material, restoration and restoration of sloping ground, and is injected into the ground. It is possible to locally procure non-fluid and self-hardening consolidated material, and to provide an excellent soil improvement method that can benefit the civil engineering application field in the construction industry by making it possible to perform optimum construction on the ground to be improved. It is assumed that.

[0017]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the construction of the invention of the present application for solving the above-mentioned problems is to improve soft ground and to improve the ground of existing structures. In order to improve the ground by the compaction grouting method to cope with the function deterioration caused by uneven settlement and liquefaction of the ground, the base ground was drilled by the drilling plant when the local procurement and adjustment of the cement used in the ground area to be improved. Drilling to reach the supporting layer of the cement, and then, at a non-fluid, self-hardening compaction plant injection plant, a predetermined solidifying material such as cement, a soil component such as silt, and a powder such as sand and gravel. The mixing and stirring with the particles are adjusted so that the supply amount of each of these powder and granular materials and the press-fitting pressure of the compacted material are set to the optimum conditions, and the compacted material press-fitted into the ground is No runaway or stray, no quality change, no pressure Technical measures were taken to maintain the press-fit state in the original site over time, form a consolidated mass, compress the side ground, and ensure that the ground improvement was as designed. .

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

4, 5, and 6 are described using the same reference numerals.

In the embodiment shown in FIG. 3, reference numeral 8 denotes a ground improvement system used for carrying out the invention of this application, and the hardware configuration as a subsystem thereof is, as shown in FIGS. A drilling plant 9 to be installed on the ground 12 to be improved, and a non-fluid self-hardening consolidated material by a predetermined solidified material and another powder material described later with respect to the ground in the ground 12. The plant comprises a fixed-quantity mixing plant 10 and a consolidated material press-fitting plant 11. Each plant will be described in detail. In the embodiment shown in FIG.
The drilling operation is performed in a predetermined manner.

On the side of the drill 13, a drilling water tank 16 for assisting drilling and a pump 1
7 is connected, and further, a compressor 18 is connected.

On the other hand, in the fixed-quantity mixing plant 10 with a solidified material such as cement and other powdery and granular materials, cement 2 as a solidified material carried in by a dump truck 19 is used.
0 and soils such as silt (lubricating material for pumping) 21 and sand and fine gravel 22 which are carried in at predetermined intervals are supplied to hoppers 24, 25 and 25 'by backhoe 23 in a fixed amount. Further, in the mixing plant 10, a water tank 26 is provided, and a control vehicle 27 equipped with a generator is carried in and set along with the water tank 26, and has a predetermined control function as shown in FIG. It has been like that.

In the press-fitting plant 11, a screw-type mixer 30 is interposed between the pump hopper 29 of the pump car 28 and the quantitative mixing plant 10, and from the pump hopper 29 to the press-fitting pipe 4 of the press-fitting device 32. The non-fluid self-hardening solidified material mixed and stirred in a predetermined manner through the hose 31 is press-fitted in a predetermined manner.

A hopper 24 for storing the cement 20 of the solidified material, a hopper 25 for storing the soil 21 such as silt, and a hopper 25 'for storing the fine gravel 22'.
As shown in FIG. 3, each is supported by a frame (not shown) via a well-known load cell 34, together with each gate 35, an electromagnetic valve 35 ', and a flow meter 34' of the water tank 26.
Is electrically connected to a computer 36 and is a non-flowable, self-curing solid with a low slump (0-6 centimeters slump) close to 0 at a predetermined ratio according to a setting program 37 and a pre-bored data program 38. The mixture is supplied to a screw-type mixer 30 for performing a predetermined blending to be a binder, and is uniformly dispersed, kneaded and stirred by a driving device 42.

Then, the kneaded material is mixed with the mixer 30.
Is supplied to a reciprocating pump 43 driven by a motor 44 of a pump hopper 29, and is press-fitted into the ground 12 via a press-fitting pipe 4 of a press-fitting plant 32. The data of the supply amount, which is the weight difference before and after opening the gate 35 of each load cell 34, is input to the computer 36, and the processing data in the computer 36 is recorded in the memory 40. , The pressure measured by the pressure gauge 34 '', and, compared with the slump measured separately at a predetermined timing, and, at the same time, to serve as reference data for the subsequent and subsequent construction processing, and at the same time the drilling diameter, as well as,
The instruction data 39 such as the compounding amount and the press-in pressure, which are fed back to the compounding amount and are in accordance with the program 37 in advance from the computer 36 and the program from the pre-bored on-site data program 38, can be printed out and used at any time. It has been like that.

In the above-described system, when performing ground improvement work such as soft ground improvement work or, as described above, restoration work for uneven settlement or liquefaction of the ground on which the building is installed, etc. Is provided with a record data program 37 of the work performed so far including the experiments and the like, which is the most suitable data for the improvement work of the ground 12, and is prepared by preboring the ground 12 manually inputted. Local data program 3
8 is prepared and input to the computer 36 in advance.
At the same time, a dump truck 19 or the like is used to set cement 2
, And sediment sediment 21, such as silt, sand,
The debris 22 is also stored.

Depending on the design, fly ash, bentonite and the like may be carried in as other powder and granular materials and stored in a predetermined manner, and the corresponding hoppers 24, 2 of the fixed quantity mixing plant 10 may be stored.
5, 25 ', and a predetermined amount of water 33 is stored in the water tank 26.

The hoppers 24, 25, 2
The stored weight of each of the 5 'is input to and recorded in the computer 36 via the load cell 34, and the used amount is measured by the weight loss calculation through the computer 36.

The amount of water 33 used in the water tank 26 is input to a computer 36 via a flow meter 34 '.

First, the computer 36 totally programs the ground improvement work process by using all the inputted programs and starts operation.
The drilling data 39 is printed out, the drilling drill 13 is operated based on the data 39, and a predetermined drilling is performed on the ground 12.

Of course, the drilling is performed at predetermined intervals.

Then, in the post-drilling press-fitting plant 11,
With the press-fitting pipe 4 of the press-fitting device 32 facing the borehole, the mixing plant 10 is operated, and the computer 36 operates the hopper 24 of the cement 20, the hopper 25 of the soil 21, and
The gates 35 of the hopper 25 ′ for the sand and debris 22 are opened, and the material from these is supplied to the mixer 30.

In this case, each of the gates 35 and the electromagnetic valves 35 ′ are opened at a set opening according to the programs 37 and 38 for a set time, so that each cement 20, the soil 21, the sand, the debris 22, and Water 33 is set amount mixer 3
0 is supplied.

Then, the motor 42 of the mixer 30 is driven, and the cement 20 and the sand 2 are
1. Gravel 22 and water 33 are mixed and stirred in a uniformly dispersed state,
A non-flowable, self-curing consolidated material having a predetermined low slump (0 to 6 centimeters slump) close to the above is formed and supplied to the reciprocating pump 43 of the pump hopper 29, and the motor 44 is operated by a command of the computer 36. As a result, the press-in pump 43 is operated, and the ground 12 is press-filled into the ground 12 from the tip of the press-in pipe 4 of the press-in device 32 of the press-in plant 11.

The above process is performed at a predetermined ground level after injection,
Alternatively, the process is repeated until the pressure or the injection amount is reached, and when the predetermined level, pressure, or injection amount is achieved, the process proceeds to the next stage.

In this case, the bottom-up method is mainly used for the press-fitting in the ground improvement mode, and the top-down method is used for the ground inclination restoration and the liquefaction prevention. The bulb-shaped blocks 5 are press-filled in a stacked manner in a mutually joined state to compress the side ground.

The injection pressure is detected by a pressure gauge 34 ″ and input to a computer 36.

In this case, the amount of press-fitting material from the press-fitting pump 43 at each stage is input to the computer 36 by measuring the supply amount of each material by each load cell 34 and flow meter 34 '. The reference numeral 36 designates a set flow rate and a set pressure for each stage in accordance with a setting program, and instructs up / down of the stage.

In this ground improvement construction work, although the degree of non-fluidity and slump of the compacted material naturally differs depending on the properties of the ground 12, the experiments up to that point need to be dealt with. The optimum blending amount to give a desired slump is inputted by a computer 36 by a database 36 including a database including a pre-boring process and a data program 38 by pre-boring prior to the construction. By controlling the supply amount of other powdery material such as fly ash or bentonite to the mixer 30, it is possible to set a low-slump self-curing compaction material having an optimal blending and press-fill it. It is possible to program the top-down or bottom-up stage pitch, etc. for the press-fitting. It can be is a matter of course.

Thus, in each embodiment, the press-fitted consolidating material solidifies with time, compresses and compacts the surrounding soil, and performs predetermined ground improvement and uneven settlement, restoration, and liquefaction prevention. Etc. are performed as designed over time.

In this case, the bottom end of the press-fitting pipe 4 reaches the support layer regardless of the bottom-up method or the top-down method.

It should be noted that the embodiments of the invention of this application are not limited to the above-described embodiments. For example, not only the improvement of the ground but also the improvement of the general soil layer in the deep underground, the underpinning and the shielding tunnel Of course, it can be applied to peripheral protection.

As for the design change, it is a matter of course that the construction with the optimum consolidation material for the ground can be appropriately performed by changing the data by the computer.

[0044]

As described above, according to the invention of this application, a non-flowable and self-hardening solidified material having a low slump of 0 to 6 cm into the ground is basically press-filled into the ground. Is performed via a reciprocating pump, maintains the original position of press-fit filling in self-curing over time, does not become a consolidated mass, there is no stray or runaway in the ground, the uniformity of components does not change, In ground improvement methods such as soft ground improvement and uneven settlement settlement using superior compaction grouting to compress the surrounding ground, and solidification materials attached to the drilling plant for the ground, etc. By adjusting the compounding of the material by a quantitative mixing plant with the powder and granular material, and adjusting the injection pressure through a computer, it is non-fluid and self-curing according to the delicate and complicated properties of the ground. Optimal press-fitting of consolidated material An excellent effect that Rukoto can be achieved.

[0045] The reliable ground improvement and restoration, etc., by compaction grouting can be performed by using locally procured materials for the delicate properties of the ground.
The excellent effect that the kneading by the optimal quantitative blending of the powder material is performed as designed is achieved.

Therefore, not only the effective use of the land by the improvement of the soft ground, but also the improvement of the ground for repairing the collapsed ground due to the unequal settlement of the ground having the existing structure, the inclination or the liquefaction due to the earthquake, etc. An excellent effect of performing in an optimal state is exhibited.

There is also an effect that the ground improvement can be extended to the deep ground.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a drilling plant used in an embodiment of the present invention.

FIG. 2 is a schematic longitudinal sectional view of a press-fitting plant and the mixing plant.

FIG. 3 is a solidification system diagram of a fixed-quantity supply mechanism of each material in a mixing plant.

FIG. 4 is a schematic sectional view of the improvement construction.

FIG. 5 is a schematic cross-sectional view of ground improvement work by compaction grouting based on the prior art.

FIG. 6 is a schematic cross-sectional view of unequal settlement repair work based on the conventional technology.

[Explanation of symbols]

 Reference Signs List 12 ground 20 solidified material 21, 22 other powder material 10 mixing plant 32 press-in plant 13 drilling plant 8 ground improvement system

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Samson W. Bandeimiya 11575 Waazworth Street, North Bloomfield, Colorado, United States of America (56) References JP-A-63-32016 (JP, A) JP-A-62-65727 ( JP, A) JP-A-57-205612 (JP, A) JP-A-63-22913 (JP, A) JP-A-62-38944 (JP, U)

Claims (4)

(57) [Claims] 1. A ground improvement method in which a consolidated material is press-filled into a ground to be improved. A solidified material and another powder material are mixed and mixed in a set amount to obtain a low-slump, non-flowable and self-hardening material. A soil improvement method comprising: preparing a solidified solid material; laminating blocks that are joined to each other at a predetermined stage via a hole to compress the surrounding ground. 2. The method for improving a ground according to claim 1, wherein the press-fitting of the non-flowable, self-setting hardening material is used for ground improvement. 3. The method according to claim 2, wherein the press-fitting of the consolidated material into the ground is performed by a bottom-up type, a top-down type, or a combination of both types. The ground improvement method described. 4. The ground improvement method according to claim 1, wherein the press-fitting of the consolidated material is used for restoring the surface change.