JPH0821176A - Soft ground improvement device - Google Patents

Abstract

(57) [Summary] [Purpose] To construct a compact soft ground improvement device equipped with a long soft soil solidification machine. [Structure] The soft soil solidifying machine 11 is provided in a yagura 12 which is erected substantially in the center of a self-propelled base 13 provided with a crawler 19. The soft soil layer solidifying machine 11 is held at the base of the yagura 12 and penetrates into the ground 14. A holding, guiding, and elevating device 20 is provided at the base, and the elevating cylinder 25 pushes the soft soil layer solidifying machine 11 into the ground 14 and pulls it out of the ground 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft ground improvement apparatus used for preventing ground subsidence when constructing a structure on soft ground.

[0002]

2. Description of the Related Art Conventionally, various construction methods have been used for improving soft ground. As a typical example, for example, "Construction Machinery" magazine, March 1981 issue, pages 59 to 6
A jet agitation method and the like, which are described on page 3 as "New ground improvement method by pneumatic feeding of powder material", are known.

FIG. 10 shows the work sequence of the jet agitation method. As the mechanical equipment used for the spraying method, equipment provided with a soft soil layer solidifying machine 1 elongated in the vertical axis direction is used. In this equipment, the soft soil layer solidifying machine 1 becomes considerably taller when it is pulled out, so a tall yagura 2 which is taller than the soft soil layer solidifying machine 1 in the pulled out state is set up at one end of the base 3. To do. The base 3 is installed on the surface of the soft ground 4. The soft soil layer solidifying machine 1 has a rotating shaft 5 and the rotating shaft 5
A stirring blade 6 is provided at the lower end of the. After installing the soft soil layer solidifying machine 1 as shown in FIG. 10 (1),
Drilling is performed as shown in FIG. When the stirring blade 6 is rotationally driven while inserting the soft soil layer solidifying machine 1 into the ground 4 by its own weight, the drilled holes 7 are formed in a columnar shape in the soft ground 4. As shown in FIG. 10 (3), when the drilling to the predetermined depth is completed, the rotary shaft 5 is pulled up along the tower 2.
When the pulling up of the rotary shaft 4 is completed, as shown in FIG. 10 (4), a powdery improver such as cement is injected into the hole-drilling portion 7 in the ground 4 by compressed air to be solidified to improve the solidification. The pillar 8 is formed.

A more detailed description of the soft soil solidifying machine is disclosed in, for example, Japanese Utility Model Publication 58-35705. This publication shows an example of mounting a soft soil solidifying machine on a work boat to improve the soft soil layer on the seabed. In order to improve the soft ground, it is necessary to form a plurality of improved consolidation columns 8 at narrow intervals as shown in FIG. 10 (4). For this reason, for land use, a self-propelled soft ground improvement device is often used with the same configuration as the crawler type pile driving and swinging yard 9 as shown in FIG.

[0005]

In a self-propelled soft ground improvement device used on land, a crawler-type traveling device has a guide hole at a front end thereof for lifting and lowering a soft soil solidifying machine. The soft soil solidifying machine is moved up and down at the front end of the traveling device. For this reason, the yagura for suspending the soft soil solidifying machine needs to be erected from the traveling device to a height higher than the machine length of the soft soil solidifying machine. In addition, when the soft soil layer solidifying machine is lowered into the soil by its own weight and when the soft soil layer solidifying machine is raised from the soil, the directions of the loads acting are opposite. Further, since the load acts on the tip of the traveling device, it is difficult to control the trajectory of the soft soil solidifying machine when descending and when ascending. Further, since the soft soil solidifying machine is generally only suspended by a winch or the like, it is impossible to cope with a load exceeding the dead weight of the machine when it penetrates into the ground. Further, it is necessary to move the crawler type traveling device every time the ground improvement work is performed, and it is difficult to perform a precise improvement work, that is, to secure a lap amount when wrapping and improving the already improved portion.

[0006] In particular, in the improvement of deep deep soft ground on land, if the conventional apparatus and method are applied as they are, the following problems will become apparent.

The mechanical guide device and the suspension device become long and large.

In order to cope with the eccentric load, a larger counter weight or out trigger is required.

In order to secure stability, the size of the device becomes large.

Despite the above problems, it is possible to expand and apply the conventional apparatus and method as they are to manufacture and realize a deep-depth soft ground improvement apparatus. However, the mechanical device becomes extremely large, and there are drawbacks in terms of construction, such as the mobility of the equipment required for land construction and the accuracy and precision required for ground treatment. There is a strong demand for a new configuration of the device that reduces these drawbacks.

It is an object of the present invention to provide a stable and accurate ground improvement efficiently even if a long soft soil solidifying machine for a large depth is installed without increasing the size. It is to provide an improved device.

[0012]

DISCLOSURE OF THE INVENTION The present invention provides a soft soil solidifying machine for inserting a soft soil solidifying machine extending in the vertical axis direction from the surface of the soft soil to strengthen the soil layer. Generally installed in the center, a base that can move in the horizontal direction, and a stand that stands upright on the base and that surrounds the soft soil solidifying machine and guides it vertically, and that is installed on the base of the tower. And a holding mechanism that holds a load of the soft ground solidifying machine and holds the soft ground solidifying machine.

Further, the height of the yagura of the present invention is characterized in that it is up to the vicinity of the center of gravity of the soft soil layer solidifying machine when it is pulled up.

The holding mechanism of the present invention is characterized in that it is provided with a plurality of lifting jacks, and the expansion and contraction of the jacks allows the soft soil layer solidifying machine to be pushed into or pulled out of the ground.

Further, the soft soil layer solidifying machine of the present invention is characterized in that it can move in a plane in the yagura.

[0016]

According to the present invention, the soft soil layer solidifying machine is mounted substantially at the center of the base. A yagura is installed upright on the base to surround the soft soil solidifying machine, and a holding mechanism for holding the load of the soft soil solidifying machine is held at the base of the yagura. The soft soil solidification machine is inserted into the ground from the center of the base and is pulled out from the ground, so even if a long soft soil solidification machine for large depth is installed, the base Since an eccentric load is not applied to the device, it is not necessary to provide a counterweight or an out-trigger to correct the eccentricity, and stable operation and downsizing of the device are possible.

Further, according to the present invention, the soft ground solidifying machine is held by the base of the tower and it is not necessary to suspend it from the top of the tower. For this reason, when the soft soil solidification machine is pulled up, the soft soil solidification machine can be held in a substantially vertical state if the height of the tower is close to the center of gravity thereof. As a result, the size of the soft soil improvement device can be made smaller than the length of the soft soil layer solidifying machine.

Further, according to the present invention, the pushing of the soft soil layer solidifying machine into the ground and the pulling up from the ground are performed by a plurality of lifting jacks, so that stable work can be performed.

According to the invention, the soft soil layer solidifying machine is
Since it can be moved in a plane in the yagura, it is possible to improve the ground at multiple places with the base installed at the same place.
Since it is not necessary to horizontally move and position the entire apparatus on the soft ground, efficient and accurate work can be continued.

[0020]

1 and 2 show a schematic structure of a soft ground improvement apparatus according to an embodiment of the present invention. 1 shows a front view and FIG. 2 shows a right side view. The long soft soil solidifying machine 11 is inserted into the yagura 12 and guided.
The tower 12 is erected substantially in the center of the base 13. The base 13 is installed on the surface of the soft ground 14 to be improved. The soft soil layer solidifying machine 11 has a rotating shaft 15 extending in the vertical direction, and a stirring blade 16 is provided at the lower end of the rotating shaft 15. At the upper end of the rotating shaft 15, a casing 17
And a motor 1 for driving the rotary shaft 15 to rotate.
8 are provided. In the casing 17, the motor 1
A mechanism and the like for decelerating the rotational drive of 8 and transmitting it to the rotary shaft 15 are housed. Crawler 19 on the base 13
Is provided, and can run on the surface of the ground 14.

3 to 9 show a more detailed structure of the soft ground improvement apparatus of the embodiment shown in FIGS. 1 and 2. 3 is a front view of a main portion, FIG. 4 is a front view of an upper portion, FIG. 5 is a front view showing a drilled state, FIG. 6 is a sectional view taken along the section line AA of FIG. 2, and FIG. 2 is a sectional view taken along section line B-B of FIG. 2, FIG. 8 is a sectional view taken along section line C-C of FIG.
Shows enlarged views of the D portion of FIG. 3, respectively. In these figures, a holding / guide / elevating device 20 is provided at the base of the yagura 12. Guide devices 21 and 22 are provided at an intermediate portion and a top portion of the yagura 12, respectively. Holding / guide / elevating device 20 and guide device 2 for these
The columns 1 and 22 guide a column 23 that supports the rotary shaft 15 to approximately the center of the yagura 2. The soft soil layer solidifying machine 11
It is possible to move horizontally within the range 11a. The rotating shaft 15 is rotatably supported by a bearing 24 provided around the column 23. The column 23 is displaced up and down by an elevator jack 25 provided on the holding / guide / elevator 20.

On the crawler 19, there are provided an operation chamber 26 for operating the soft soil solidifying machine 11 shown in FIG. 2, a hydraulic unit 27 for supplying pressure oil to hydraulic actuators such as the lifting jack 25, and the like. To be The supply of power to the motor 18 for rotating the rotating shaft 15 and the supply of powder of cement or the like for ground improvement are prevented by the guide reels 28 and 29 shown in FIG. Via 30.

As shown in FIG. 6, in the holding / guide / elevating device 20, a pair of lifting jacks 25 are provided so as to face each other.
It can be moved in the X direction by the moving jack 31,
Further, in the upper guide devices 21 and 22, there is no device to which the lifting jack 25 and the moving jack 31 are attached (FIG. 7), but the prop 23 can be planarly moved in the X direction by the X-direction moving jack 34. A Y-direction moving jack 32 is provided in the Y-direction, and the support column 23 can move in a plane within the tower 12. The lifting jack 25, the X moving jack 31 and the Y moving jack 32 are
Are supported by sliding jacks 33 that are slidable on the horizontal beams.

As shown in FIG. 7, the bearing 24 is composed of the columns 23.
It is provided around the. The support guide 3 is provided on the column 23.
5 is also provided and receives a lifting drive force from the lifting jack 25.

As shown in FIG. 8, four rotary shafts 15 are provided, and the planar loci of the respective stirring blades 16 overlap each other and wrap. When the ground 14 is drilled and then solidified, an improved consolidated column having the cross-sectional shape of the contour line 16a is obtained.

As shown in FIG. 9, a support guide 35 is provided on the support column 23 at intervals in the axial direction. Each support guide 35 engages with the clevis 36 at the tip of the rod of the lifting jack 25, and vertically displaces the column 23 in response to expansion and contraction of the rod. When moving the clevis 36 from one bearing guide 35 to the next bearing guide 35, the other lifting jack 25 needs to be engaged with the bearing guide 35. Therefore, a plurality of lifting jacks 25 are required. With such a mechanism, the soft soil layer solidifying machine 11 can be forcibly pushed into the ground 14 by the jack force without depending on its own weight. Since it is possible to generate a penetration force equal to or more than its own weight, even if there is a penetration resistance in the middle of the ground 14, the soft soil layer solidifying machine 11 can be forcibly lowered against the resistance.

When one improvement process is completed, each of the horizontal moving jacks 25, 31, 32, 33 is moved by a predetermined span to improve the soft soil solidifying machine 1 as an improved machine.
1 is moved horizontally, and ground improvement work is continued in the second and subsequent treatments. In this way, the horizontal movement controls the stroke of each jack and positions it mechanically in detail, so construction accuracy such as management of the amount of lap with the improved part, and mechanical movement of the guide when moving up and down. It is also possible to control the posture of the improved machine body and to perform accurate construction. By repeating the construction, it is possible to continuously perform the ground improvement work a plurality of times within a range where the soft soil layer solidifying machine 11 does not hinder the movement in the yagura 12. After that, the crawler 19 moves to the next adjacent improvement area, and the same ground improvement work is sequentially repeated to perform the ground improvement work in a predetermined area range.

According to the present embodiment, on the moving device such as the crawler 19 which travels on the improved ground surface, there is provided equipment for holding, guiding and lifting the improved machine at the central portion, and the holding, guiding and lifting device is a crawler. It is possible to move the improvement surface to some extent without moving the device, and the holding / guide / elevating device is placed in the tower 12 on the crawler device, the improved machine is held by a hydraulic jack, etc., and the improved machine penetrates into the ground. Since the penetration force at this time is suppressed or a penetration force more than the weight of the improved machine is generated to penetrate into the ground 14 and the working goat is short, the posture control of the improved machine can be easily and accurately performed. . Further, since the improvement of the crawler traveling device can be performed a plurality of times by positioning the crawler traveling device once, the construction speed can be increased, and the economical efficiency of construction can be improved. Further, since the plane movement can be performed accurately and easily, the ground can be improved accurately by ensuring the precise amount of lap. Further, since it is not always necessary to provide the tower 12 having a length equal to or longer than the length of the soft ground solidifying machine 11, it can be economically realized as a construction apparatus using the long soft soil solidifying machine 11 especially for large depth. Moreover, since the penetration force of the soft soil layer solidifying machine 11 can be freely controlled to be equal to or more than its own weight and less than its own weight, stable operation is performed without being affected by the presence or absence of obstacles in the ground 14, etc. be able to.

In the present invention, although jacks are used for raising and lowering the improved machine, although not particularly shown, racks are attached to both side surfaces of the pillars 23 instead of the support guides 35 on the side surfaces of the pillars 23, and instead of the lifting jacks. By using a pinion that engages with a rack, the soft soil layer solidifying machine 1 is driven by driving the pinion.
It is also possible to insert and elevate 1.

[0030]

As described above, according to the present invention, since the soft soil solidifying machine is installed in the center of the base, the base is not subjected to an eccentric load, and stable operation is possible. Can be done efficiently.

Further, according to the present invention, since the height of the tower is shorter than the length of the soft soil solidifying machine, the apparatus can be made compact as a whole.

Further, according to the present invention, since the lifting jack is expanded and contracted to push the soft soil layer solidifying machine into the ground and pull it out of the ground, the weight of the soft soil layer solidifying machine and the softness of the ground are reduced. It is possible to move up and down stably without being affected by the degree.

Further, according to the present invention, the soft soil layer solidifying device can move in a plane in the yagura. After the soft ground improvement device is installed once, the ground can be improved multiple times at the same position, so that the ground improvement can be efficiently advanced.

[Brief description of drawings]

FIG. 1 is an overall front view of an embodiment of the present invention.

FIG. 2 is a right side view of the embodiment of FIG.

FIG. 3 is a front view of the main part of the embodiment of FIG.

FIG. 4 is a front view of the upper portion of the embodiment of FIG.

FIG. 5 is a simplified front view showing a state where the embodiment of FIG. 1 is improving the ground.

6 is a cross-sectional view taken along the section line AA in FIG.

FIG. 7 is a cross-sectional view taken along section line BB of FIG.

8 is a cross-sectional view taken along the section line C-C in FIG.

FIG. 9 is a partially enlarged view of a portion D in FIG.

FIG. 10 is a simplified front sectional view for explaining a conventional soft ground improvement method.

FIG. 11 is a simplified front view showing the configuration of a conventional crawler type pile driving and ladle.

[Explanation of Codes] 11 Soft soil solidifying machine 12 Yagura 13 Base 14 Ground 15 Rotating shaft 16 Stirring blade 19 Crawler 20 Holding / guide / elevating device 21, 22 Guide device 23 Strut 24 Bearing 25 Elevating jack 31 31 X moving jack 32 Y-moving jack 35 Bearing guide 36 Clevis

Claims (4)

[Claims] 1. A soft soil improvement device for inserting a soft soil solidifying machine extending in the vertical axis direction from the ground surface of the soft soil to strengthen the soil layer, wherein the soft soil solidifying machine is generally installed at the center part. , A horizontally movable base, and a yag which stands upright on the base and surrounds the soft soil solidification machine and guides it vertically, and is installed at the base of the yagura to support the load of the soft ground solidification machine. A soft ground improvement device comprising a holding mechanism for receiving and holding the ground. 2. The soft ground improvement apparatus according to claim 1, wherein the height of the yagura is up to near the center of gravity of the soft soil layer solidifying machine when the soft soil layer solidifying machine is pulled up. 3. The holding mechanism comprises a plurality of lifting jacks, and the expansion and contraction of the jacks allows the soft soil layer solidifying machine to be pushed into the ground or pulled out from the ground. Or the soft ground improvement device according to 2. 4. The soft ground improvement apparatus according to claim 1, wherein the soft soil layer solidifying machine is movable in a plane in the yagura.