JPH08296219A - Method and device for improving shallow bed ground - Google Patents

Abstract

PURPOSE: To accurately improve the shallow bed and soft ground at a low cost by relatively rotating an outer sleeve and an inner sleeve, and injecting the improving material from nozzles, which are provided in both the sleeves in the axial direction with a phase difference. CONSTITUTION: A rotary stabilizer 5' is suspended form the tip of an arm extended from a truck, and a sprocket 17" is rotated through chains 18, 18 of the rotary stabilizer 5' so as to rotate a rotary shaft 9'. An outer sleeve fixed to the sprocket 17" is relatively rotated to an inner sleeve, which is provided on the same shaft with the outer sleeve. When nozzles of both the sleeves, which are provided in the axial direction with the predetermined pitch and with a phase difference in the circumferential direction, coincide with each other, the improving material 5 is intermittently injected. The improving material 15 can be thereby evenly injected without unevenness, and while clogging of the nozzle can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The disclosed technology belongs to a technical field in which surface soil such as soft soil is scattered with an improving material such as cement and mixed and stirred with the surface soil to be improved.

[0002]

2. Description of the Related Art As is well known, in a country with a narrow land area and in a terrain condition in which many mountainous forest areas are close to a complicated coastline, it is used for various industrial facilities and houses. Since the plains to be served are limited, it is necessary to improve and effectively use the soft ground such as shallow beaches, rivers and basins of lakes and marshes. Are being offered to people.

In the conventional technology, the so-called chemical solution injection method was mainly used. However, the chemical solution injection method injects a liquid chemical solution into the ground, which causes pollution problems such as groundwater contamination. In addition, there is a problem that the reaction speed is slow because it is a liquid-liquid reaction between groundwater and the injected chemical liquid, and the gel time of the reaction time is remarkably delicate in the equivalence relation, and its management control is complicated. In addition, the so-called powder injection stirring method in which powder improving materials such as cement are recently injected into the ground via transportation means such as air and solidified over time has been researched and developed, and many achievements will be made. Is becoming.

However, such a powder injection stirring method is used for the middle layer of several tens of meters or hundreds of meters from the ground surface.
Alternatively, it is extremely effective for ground improvement in the deep layer, but it has a negative point that it is unsuitable for soft ground improvement of so-called surface ground of large land such as exercise facilities, parking lots, and vacant lots. Despite this, the need for ground improvement of such surface ground has become more demanding than in recent years.Therefore, a pontoon type bogie is set in the surface soft ground to set cement, etc. on the surface ground. Shallow ground improvement technology has been developed in which the improvement material is sprayed and mixed with the soil in the ground by stirring.

[0005] The outline of the conventional shallow layer ground improvement construction will be briefly described with reference to the drawings starting from FIG. 7, and as shown in FIGS. 7 and 8, a pontoon type is provided on the shallow ground 1 of the soft ground. An arm 4 having a Yumbo type carriage 3 having a float type crawler 2 loaded therein and extending from above the carriage 3.
Operate the rotary stabilizer 5 that can be moved up and down and left and right at the tip of the pilot from the cockpit 6, and then improve the cement or other improved material that has been sprayed on the shallow ground 1 in a predetermined thickness. The soft ground of the shallow ground was improved by mixing and stirring the ground at a depth of 2 to 3 m from the surface ground to disperse the ground in the ground.

[0006]

By the way, in the rotary stabilizer 5, as shown in FIGS. 9 and 10, the rotary shaft 9 pivotally supported by the bearing 8 provided at the lower end of the frame 7 is provided at the upper part. Is rotated by a drive device 10 provided in the sprocket / chain mechanism or the like, and a predetermined number of mixing fins 11, 11 ... The sprayed improving material is pushed into and mixed with the shallow ground, and the arm 4 is moved left and right by the cockpit 6 so that the soil in the shallow ground 1 and the improving material are mixed and stirred in a scattered manner.

By the way, as shown in FIGS. 9 and 10,
The improving material 15 such as cement is extended along the frame 7 and is fed from the feeding port 14 at the upper part to be stirred blades 12, 12
Between the mixing fins 11 and 1
1 is mixed and agitated with the soil in the shallow ground 1 to be scattered.

Therefore, in order to uniformly mix the soil in the shallow ground 1 in a plane (lateral direction), the arm 4 must be moved from the cockpit 6 to the left and right, and the ground resistance is large. However, there is a difficulty that the right and left movement is difficult, and as a result, it is difficult that the average mixed state is revealed.

Further, since the nozzle 16 is fixedly disposed at the tip of the frame 7 and is interposed between the stirring blades 12, 12, clogging or unevenness may occur depending on operating conditions. There was a drawback that jetting occurred, and mixing and stirring with the soil of the shallow ground 1 could not appear.

Although it is conceivable that a plurality of nozzles 16 are provided at the tip of the frame 7, the frame 7 is concerned.
There is an inconvenience that the degree of freedom in design is small due to the complexity of the structure of the tip part of the ground, so that the ground improvement in such a mode in the Yumbo type shallow ground 1 as a result is There is a negative point that it can not be done as designed, and there is a negative point that the truck 3 must be reciprocated over the shallow ground 1 and the predetermined work must be repeatedly executed, resulting in a decrease in construction efficiency. However, there was a demerit that it caused high costs.

[0011]

OBJECT OF THE INVENTION The object of the invention of the present application is to realize the lateral unevenness by the conventional Yumbo type construction device in the improvement construction of the surface ground of the shallow soft ground, which is potentially in great demand based on the above-mentioned prior art. A technical issue that should solve the problems of incompatibility of soil and soil, clogging of nozzles, and uneven injection, and while allowing the arm to move left and right, the injection amount of the improver in the axial direction An even shallower ground improvement method that is beneficial to the field of civil engineering applications in the construction industry by ensuring that construction is performed as designed without causing clogging in the nozzles, etc. And an apparatus for direct use in the method.

[0012]

In order to solve the above-mentioned problems, the structure of the invention of the present application, which is based on the above-mentioned object, is intended to solve the above-mentioned problems when the surface ground of the soft ground is improved. , Carrying in a Yumbo type trolley with a float type crawler, etc., and hanging a rotary stabilizer vertically on the tip of the arm,
A lower driven sprocket is rotated by a chain via a sprocket of a drive mechanism such as an upper hydraulic motor, and a rotation shaft is provided on the lower sprocket, and the rotation shaft is an outer sleeve and the outer sleeve is concentric with the outer sleeve. An inner sleeve is provided to fix at least one of the sleeves, or a relative rotation is allowed by rotating the sleeve, and one side of the sleeves has a predetermined pitch in the axial direction.
And, opening a plurality of nozzles having a phase difference in the circumferential direction,
By the relative rotation of both sleeves through the sprocket, an improved material such as cement, which is air-fed to the inner sleeve from a nozzle in a downward direction at a position where the nozzles coincide with each other, is jetted into the soil of the shallow ground, Along with a plurality of nozzles, the scattered state of the improving material and the soil which is averaged as much as possible in the axial direction appears, and the mixing fins provided at a predetermined pitch in the chain mix and stir the improving material and the soil. Also, the transport air is pumped, and the axial pitch of the nozzle between the outer sleeve and the inner sleeve and the phase difference in the circumferential direction are initially set, or the rotation is provided on the upper sprocket. The improvement material is fed to the outer sleeve and the inner sleeve of the shaft through a plurality of nozzles in the axial direction having a predetermined axial pitch and a phase difference in the circumferential direction similar to the above. Similarly, the improvement material is ejected laterally as uniformly as possible through a nozzle provided on the lower rotary shaft via a hose or a passage such as a pipe, and is ejected into the ground by a mixing fin provided in the chain. The improved material such as cement is pushed into and mixed with the soil in the shallow ground, and the transport air is pumped out, so that no clogging or uneven ejection is generated at the part where the nozzle is fixed, Lateral movement of the arm in the lateral direction is suppressed as much as possible, the shallow layer ground improvement as designed is efficiently performed, and technical measures are taken to shorten the construction period and reduce the cost. Is.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the invention of this application will be described with reference to FIGS.
The explanation is based on the following.

It should be noted that parts that are the same as those in FIG. 7 and thereafter will be described using the same symbols.

In the embodiment shown in FIGS. 1 to 4, A is a shallow ground improvement device which is one of the gist of the invention of the present application, and is loaded into a predetermined soft ground 1 and set for operation. On the trolley 3'supported by a pair of pontoon type crawlers 2 and 2, a so-called whirling type cockpit 6 can extend and retract the link type arm 4 and freely rotate (movable left and right). ), And a rotary stabilizer 5'is suspended from the tip of the arm 4 via a link.

In the rotary stabilizer 5 ', as shown in FIGS. 2 to 4, a drive device 10' such as a hydraulic motor is installed from the upper stage on a frame 7'suspended by a pin pivotally supported by a tip link of the arm 4. Drive sprocket 1 installed in
7. Intermediate sprocket 17 'Chain 1 having lowermost driven sprockets 17''fixedly mounted on rotating shafts 19 and 19' and having mixing fins 12 ', 12' ... at a predetermined pitch
The rotational force can be transmitted via the motor.

In the illustrated embodiment, one chain 18 is stretched from the drive sprocket 17 of the drive device 10 ', but the intermediate sprocket 17' and the driven sprocket 1 are provided.
Two other chains 18, 18 are further stretched between the 7 '' and the intermediate sprocket 17 '.
And the driven 17 '' between the desired mixing fins 12 ', 12
3 chains 18,18,1 having '... at a predetermined pitch
8 is stretched so that the rotational force can be transmitted synchronously.

Then, as shown in FIG. 3, an air transportation pipe 13 of cement as an improving material is arranged near one side of the frame 7 ', and a feeding port 14 is provided on an upper portion of the intermediate sprocket 17'. , Rotary shaft 9 of driven sprocket 17 ''
It is connected to the inner sleeve 21 of the '.

Thus, the lowermost driven sprocket 17 ''
The outer sleeve 2 fixed to each driven sprocket 17 '' in the rotating shaft 9'integrally provided in the
0 is coaxially mounted on the inner sleeve 21 with a mechanical seal 23 so as to be rotatable relative to the inner sleeve 21.

In the outer sleeve 20, the nozzles 16 ', 16''are installed in a predetermined plural axial directions (two in the embodiment, two at the top and the bottom at a predetermined pitch), and the inner sleeve 21 is provided. A circumferential phase difference (for example, 180 °) with respect to the nozzles 16 ′ and 16 ″ of the outer sleeve 20.
°) In the process in which the outer sleeve 20 relatively rotates with respect to the inner sleeve 21 by the driven sprockets 17 '' having the different nozzles 22, 22, the nozzle 22 of the inner sleeve 21 makes the nozzle 16 'of the outer sleeve 20. , 16 ″, the improved material 15 pneumatically transported can be ejected from the nozzles 16 ′, 16 ″ of the outer sleeve 20 into the shallow ground.

In the illustrated embodiment, the nozzle 16 '' of the outer sleeve 20 is blindly closed through the blind plug 24 at the time of initial setting so that the nozzle 22 of the inner sleeve 21 matches the nozzle 16 ''. The material 15 is adjusted so as not to be ejected.

Therefore, in the rotating shaft 9 ', the axial pitch and the circumferential phase difference of the inner sleeve 21 with respect to the outer sleeve 20 are initially set, so that the rotating shaft 9'is asynchronous at different axial positions. The nozzle 22 of the inner sleeve 21 is the outer sleeve 2
Only when the nozzles 16 ′ and 16 ′ of 0 coincide with each other through the phase difference, the improving material 15 is selectively ejected, and therefore, the average improving material is ejected in the axial direction of the rotating shaft 9 ′, so that each chain is ejected. 18. The mixing fins 12 'make the mixing state even on average, so that the ubiquitous mixing and stirring is not performed.

Thus, by opening the other nozzles 16 ", 16" of the outer sleeve 20 with the lateral pitch and circumferential phase difference different from the nozzle 16 'by the initial setting, the rotary shaft It can be adjusted to ensure an average ejection of the 9'widthwise, i.e. axial, intermittent improver 15.

Therefore, by performing the above adjustment depending on the condition of the soft ground 1 and the depth of the shallow layer,
It is possible to surely prevent the nozzles 16 ', 16''and 22 from being clogged.

Therefore, in this embodiment, it is not necessary to previously spray an improving material such as cement on the surface layer of the ultra-soft ground 1, so that the solidification phenomenon does not appear only on the surface of the surface layer at an early stage. Over the entire shallow layer including the surface of the surface layer, that is, the mixed state with the soil of the improved material averaged over the entire shallow layer such as 3 m from the surface layer appears, and moreover, from the initial stage of operation, the nozzle 16 '' The shallow ground improvement work will be carried out as designed without the occurrence of clogging or uneven ejection.

It is needless to say that the improving material is not limited to a powder improving material such as cement, but may be a slurry.

In the above-mentioned structure, the shallow ground improvement apparatus A is loaded and set on the surface layer of the predetermined soft ground 1, and the arm 4 is extended forward by a predetermined angle through the rotating seat 6 to rotate the rotary stabilizer 5 '. Driven sprocket 1 at the tip
7 ″ is brought into contact with the surface layer of the soft ground 1 to feed a predetermined improvement material 15 such as cement from the improvement material supply port 14 of the pipe 13, and the rotary shaft 9 ′ of the driven sprocket 17 ″ at the tip.
When the inner chain 21 is fed to the inner sleeve 21, the three chains 18, 18, 18 are rotated between the intermediate sprocket 17 'and the driven sprocket 17''by the drive of the drive device 10' such as a hydraulic motor. The force is transmitted, and in the lowermost driven sprocket 17 ″, the outer sleeve 20 of the rotary shaft 9 ′ rotates via the mechanical seal 23 to the inner sleeve 21 concentrically provided,
The nozzles 16 ′ and 16 ′ of the outer sleeve 20 whose initial positions are set are the nozzles 22 of the inner sleeve 21,
The improved material 15 pneumatically transported at a position corresponding to 22 is jetted into the shallow ground 1 as evenly as possible in the width direction, during which,
The transport air is pumped by the mixing fins 12 'of the chains 18, 18 and 18 that rotate in a circulating manner, uniformly mixed and mixed with the soil in the shallow ground 1 and solidified with time to a predetermined value. The shallow ground improvement will be carried out.

Of course, during this time, the blind plugs 24, 2 of the nozzles 16 ", 16" of the outer sleeve 20 are initially set.
4 is opened, the nozzle 22 of the inner sleeve 21 becomes the nozzles 16 ′, 1 of the outer sleeve 20.
6'is nozzles 16 '', 16 '' with different circumferential phase difference
From the above, it will be jetted into the soil in the shallow ground 1, and the mixing and stirring of the improving material will appear as uniformly as possible.

Of course, since the nozzles 16 ', 16'', 22 which are initially set depending on the condition of the shallow ground 1 are adjusted and set without causing phase difference or parts of the nozzles 16', 16 '', 22 to be constructed, Clogging of each nozzle does not occur.

During this time, depending on the condition of the shallow ground 1, the arm 4 is moved from the cockpit 6 to the left and right and up and down to improve the material 15 from the nozzle 16 'in the shallow ground 1 of the rotary shaft 9'. Try to achieve a uniform jet.

In this way, the shallow ground improvement work for the predetermined area can be completed within the predetermined construction period as designed.

The nozzle 16 'of the outer sleeve 20.
, 16 ″ and the nozzle 22 of the inner sleeve 21
The axial pitch and the phase difference in the circumferential direction are initially set. However, by providing an appropriate drive device such as a hydraulic motor on the rotary shaft 9 ′, the pitch in operation in the remote control system from the cockpit 6, And, it is easy for those skilled in the art to be able to adjust the phase difference,
Further, changing the size of each nozzle such as the width to intermittently eject the improvement material from each other, or allowing the improvement material to be ejected in an overlapping manner is only a range of design change.

Thus, in the embodiment shown in FIGS. 5 and 6, during the operation of the rotary stabilizer 5'in the shallow ground 1, the phase difference of each nozzle of the rotary shaft 9'is initially set and the rotary stabilizer 5'is operated. This is a mode in which the improvement material 15 can be hand-distributed in the upper part so as to cope with the fact that the inside cannot be performed, and a drive device 10 'such as a hydraulic motor provided at the uppermost end of the frame 7'. A rotary shaft 9 ″ is provided immediately below the outer sleeve 20 ′ and three nozzles 161,
Three 161 are provided with a circumferential phase difference of 120 ° at a predetermined pitch in the axial direction, a nozzle 22 ′ corresponding to the axial direction is provided in the inner sleeve 21 ′, and a hose (not shown) is provided from each nozzle 161 of the outer sleeve 20 ′. Alternatively, the inner sleeve 21 ′ of the upper rotary shaft 9 ″ is connected to each fixed nozzle of the rotary shaft 9 ′ at the lowermost end through a pipe, and the drive device 10 ″ is connected to the inner sleeve 21 ′ of the rotary shaft 9 ″.
The sprocket 171 midway by the
'Rotate the inner sleeve 21' by 120 °
The nozzles 22 ′ having a phase difference between the outer sleeve 20 ′ and the nozzles 161 of the outer sleeve 20 ′ are intermittently and sequentially arranged on the lower rotating shaft 9
In this embodiment, the improved material is uniformly ejected in the width direction and the mixing and stirring is performed in a uniform mixed state in the shallow ground 1. It is a system that can be adjusted on-the-fly during operation. In addition, the carrier air of the improving material 15 is lifted up and discharged from the gap formed in the back part of the mixing fin 12 'of the chain 18 together.

[0034]

As described above, according to the invention of this application, the powder improving material and the slurry are mixed with the soil in the shallow ground in the basically wide and large potential demand for the shallow ground improvement work. When it is allowed to solidify with time, it is not necessary to spray the powder improving material or the like on the ground surface of the surface layer in advance, so that the improving material does not drift in the wind and may cause environmental destruction or work environment deterioration. However, since the improving material can be directly carried into the shallow ground and uniformly mixed and stirred with the soil, the improvement effect is good, and the excellent effect that the soft ground can be improved as designed is exhibited.

Moreover, in the construction, since the improving material can be uniformly ejected in the lateral direction, there is no latent solidification state only in the upper portion with the passage of time after the construction, and all can be uniformly ejected. Since there is no clogging or ubiquitous jetting in the nozzle of the rotating shaft because it can be improved through, there is no interruption of construction and the construction period can be done as designed.
There is an effect that a high efficiency can be achieved, and as a result, an excellent effect that a cost can be reduced can be achieved.

In order to disperse the improving material in the ground by the rotary stabilizer disposed by suspending it at the tip of the arm extended from the construction carriage, the lower portion of the rotary stabilizer is Non-uniform jetting in the ground, that is, the improved area, is achieved by allowing the improved material to jet into the ground independently of each other through the axial predetermined pitch and the circumferential phase difference in the axial direction of the rotating shaft. The excellent effect that the omnipresence does not occur is exhibited.

Further, by providing nozzles on the lower rotary shaft by changing the pitch in the axial direction through the phase difference in the circumferential direction, the initial set state is always maintained when the ground is constant in construction. However, the improved material is fed to the nozzle of the lower rotary shaft through the circumferential phase difference at a predetermined pitch in the axial direction of the upper rotary shaft with respect to the lower rotary shaft. By doing so, it is possible to adjust the spouting state of the improved material at hand according to changes in the properties of the ground during operation, thus improving the improvement accuracy and avoiding clogging of nozzles and biased spouting. As a result, there is also an effect that the construction can be performed with high accuracy during the construction period and cost can be reduced.

In this way, compared with the powder improvement work in the middle and deep layers, the shallow layer ground improvement work, which had various difficulties, can be performed extremely smoothly and efficiently as designed. Played.

Therefore, the durability of the device is good, and maintenance,
There is also an advantage that complicated maintenance work such as inspection and maintenance becomes unnecessary.

[Brief description of drawings]

1 is an overall schematic side view of an embodiment of the apparatus of the invention of this application.

FIG. 2 is an overall schematic side view of the rotary stabilizer.

FIG. 3 is a front view of the same.

FIG. 4 is an overall schematic vertical sectional view of a lower rotary shaft of the same.

FIG. 5 is an overall schematic vertical cross-sectional view of an upper rotary shaft of another embodiment.

FIG. 6 is a schematic side view of the same.

FIG. 7 is an overall schematic side view of a shallow ground construction device in a conventional manner.

FIG. 8 is a schematic front view of the same.

FIG. 9 is an overall schematic front view of the rotary stabilizer of the same.

FIG. 10 is an overall schematic side view of the same.

[Explanation of symbols]

 1 Shallow Ground 15 Improvement Material 3 Truck 4 Arm 5 Rotary Stabilizer 15 Improvement Material 9'Rotary Shaft 16 'Nozzle 13 Improvement Material Feeding Passage 20 Outer Sleeve 21 Inner Sleeve A Shallow Ground Improvement Equipment 18 Chain 12' Stirring Fin 20 ' Drive

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[Procedure amendment]

[Submission date] May 30, 1995

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

FIG.

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 5]

[Figure 6]

[Figure 7]

[Figure 8]

[Figure 9]

[Figure 10]

Claims (7)

[Claims] 1. A method for improving a shallow ground in which a improving material is mixed and agitated in the ground by a rotary stabilizer disposed at a tip of an arm extending from a bogie with respect to the ground, in the method of improving the rotary stabilizer. A shallow ground improvement method, characterized in that the improving material is jetted into the ground independently from each other at a predetermined pitch in the axial direction of the lower rotating shaft. 2. The improvement material is fed to the nozzle of the lower rotary shaft at a predetermined pitch in the axial direction of the upper rotary shaft. The shallow ground improvement method described. 3. The method according to claim 1, wherein the phase difference in the circumferential direction of the rotary shaft is initially set.
Item 1. A shallow ground improvement method according to any one of the items. 4. A shallow ground improvement device in which a rotary stabilizer disposed at the tip of an arm extending from a trolley is equipped with a improving material feed passage on a rotating shaft having a nozzle, the rotating shaft being an outer sleeve. And an inner sleeve, and a plurality of nozzles are disposed on at least one of the two sleeves with a predetermined pitch in the axial direction, and a rotary shaft is rotatably equipped with a chain having stirring fins. A shallow ground improvement device. 5. The shallow ground improvement apparatus according to claim 4, wherein the nozzle of the outer sleeve is directed downward. 6. A shallow ground improvement apparatus in which a rotary stabilizer disposed at a tip of an arm extending from a trolley has a nozzle having a rotary shaft provided with a improving material feed passage, and the upper rotary shaft has an outer shaft. A sleeve and an inner sleeve are provided, and a plurality of nozzles are disposed in at least one of the sleeves in the axial direction with a predetermined pitch, and the nozzles are connected to the nozzles of the lower rotary shaft by a passage, thus rotating. A shallow ground improvement device characterized in that a shaft is equipped with a chain having a stirring fin so as to be rotatable. 7. The shallow ground improvement apparatus according to claim 6, wherein the upper rotary shaft is made rotatable by a drive unit.