JPH0663239B2 - Izutsu for landslide prevention and its construction method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a well structure for restraining a landslide area and a method for constructing the well.

[Conventional technology]

Conventionally, various methods are known as landslide prevention measures. Of these, the deep foundation work is to provide a large-diameter concrete structure that penetrates the landslide surface in the ground to resist the horizontal force acting on the slip surface with a large bending rigidity and shear rigidity. It is used in relatively large landslide areas.

This deep foundation work is usually an underground structure in which a large hole with a diameter of about 5 m is excavated until it reaches the ground below the slip surface, and the wall surface of the hole is rolled up with reinforced concrete. Its construction is mainly done manually. It is done by.

That is, while excavating a large diameter hole from the ground surface, the hole wall is supported by a steel liner plate or segment panel, then an excavator such as a backhoe is carried into the bottom of the hole excavated from the ground surface, and the operation is performed. A person drives the excavator to dig a hole, wraps a liner plate or segment panel around the digged hole, supports the hole wall, and digs a deep large-diameter hole. After excavating to a predetermined depth, a rebar frame is assembled in the hole and concrete is poured into this to form a large diameter well cylinder. When a liner plate is used, generally, a hole in which concrete is poured and wound up is formed between the liner plate and the hole wall.

Some of these conventional methods are mechanized, but basically, excavation, scrap discharge, liner plate or segment panel assembly, rebar assembly, concrete pouring, etc., are carried out by working inside the hole and at the bottom of the hole. I am doing it.

[Problems to be Solved by the Invention]

Since the conventional deep foundation works work at the bottom of the excavation hole, it is necessary to take safety measures against spouting groundwater, collapsing the hole wall on unstable ground, and falling objects from the ground. Although it is partially mechanized, it is difficult to increase the construction speed because the input work is mainly performed in a narrow work space.

In order to solve the above-mentioned problems, it is conceivable to construct a well made of reinforced concrete underground by using the underground continuous wall method.
However, with this method, it is necessary to use mudwater to protect the hole wall from collapsing when excavating the planned continuous wall construction in a groove shape.In the landslide area, the strata are unstable, so the mudwater escapes. And due to the increase of excess pore water pressure due to this, there is a risk of landslide inducing. Therefore, the underground continuous wall method could not be adopted.

Moreover, a hole is excavated by overlapping in the ground, an H-shaped steel pile or a steel pipe pile is inserted into the hole, and then a grout material is filled in the gap between the pile and the hole wall to construct an underground wall. The column row construction method is also known, but this column row construction method is only inserted into a straight wall, and the piles in each adjacent hole are not joined by joints, so the column row integration is insufficient. Met.

This invention has a cross-sectional rigidity equal to or higher than that of reinforced concrete, and it is possible to secure the safety of work by performing all the work on the ground, and it is possible to prevent the induction of landslides during construction, and with high efficiency. It is an object of the present invention to provide a landslide-preventing well that can be constructed and a method of constructing the well.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, in the landslide suppressing well of the first invention, a large number of vertical holes 2 penetrating the slip surface 1 are bored so as to be arranged in a circle at intervals in the ground of the landslide area, A steel pile 3 with a joint is inserted into the vertical hole 2, and a curable grout material 4 is filled between the vertical hole 2 and the steel pile 3 with a joint so as to connect to the adjacent vertical holes 2. The intermediate steel pile 6 with a joint is inserted into the provided intermediate vertical hole 5, and the intermediate steel pile 6 with a joint and the steel piles 3 with joints on both sides thereof are connected by the engagement of the joint, and the intermediate vertical hole 5 and The hardenable grout material 7 is filled between the jointed intermediate steel pile 6 and the intermediate steel pile 6.

Further, in the landslide suppressing well of the second invention, a large number of vertical holes 2 penetrating the slip surface 1 are formed in the ground of the landslide area.
Are arranged so that they line up in a circle and connect to each other,
A steel pile 3 with a joint consisting of a pile body 9 and joints 10 made of slit pipes fixed to both side surfaces of the pile main body 9 is inserted into each vertical hole 2 and hardened between the vertical hole 2 and the steel pile 3 with a joint. Grouting material 4 is filled, both side portions of the steel intermediate joint member 8 are meshed with the slit pipe joints 10 in the adjacent steel piles 3 with joints, and the intermediate joint member 8 is embedded in the hardenable grout material. In addition, the curable grout material 11 is filled in the slit pipe joint 10.

Also, in order to construct an economical landslide well with a reasonable cross-sectional rigidity, the cross-sectional rigidity of the well in the predetermined vertical section sandwiching the slip surface 1 of the ground is greater than that of other parts of the well. To do.

Furthermore, in order to achieve the above-mentioned object, in the method for constructing a well for landslide prevention of the present invention, in the ground of the landslide area, vertical holes 2 penetrating the slip surface 1 are arranged in the circumferential direction of the planned location of the well. A steel pile 3 with a joint, which is drilled and made of a steel pile main body 9 and a slit pipe joint 10 fixed so as to extend along both side surfaces of the pile main body 9, is inserted into each vertical hole 2, and A hardenable grout material 4 is filled between the vertical hole 2 and the steel pile 3 with a joint, and the adjacent steel pile 3 with a joint is provided.
The slit pipe joints 10 are meshed with each other or are connected to each other through the steel intermediate joint member 8, and the slit pipe joints 10 are filled with the curable grout material 11.

[Action]

The well 12 which penetrates into the base 13 below the slip surface 1 to a predetermined depth prevents the upper ground 14 above the slip surface 1 from slipping. The steel piles 3 with joints and the intermediate steel piles 6 with joints arranged so as to be arranged side by side in a circle are connected by the engagement of the joints, or the slit pipe joints 10 in the adjacent steel piles 3 with joints are steel intermediate joints. The steel pile with joint 3, the intermediate steel pile with joint 6, and the steel intermediate joint member 8 are connected through a member 8 and embedded in a hardenable grout material, and further, a hardenable grout is provided in a slit pipe joint 10. Since the material 11 is filled, the well 12 exhibits great strength against the bending moment, the shearing force, and the like acting on the well 12 by the earth pressure of the upper ground 14.

〔Example〕

 The present invention will now be described in detail with reference to the illustrated example.

FIG. 5 shows a steel pile 3 with a joint used in the first embodiment of the present invention, in which slits extending in the longitudinal direction of the pile body 9 are formed on both side surfaces of the steel pile body 9 made of steel pipe. The pipe joint 10 is fixed by welding, and the angle θ of the straight line connecting the center of the pile body 9 and the center of each slit pipe joint 10 is determined by the angle determined by the curvature of the cylindrical well pipe to be constructed.

FIG. 6 shows an intermediate steel pile 6 with a joint used in the first embodiment of the present invention.
T on both sides of 5 extending in the longitudinal direction of the intermediate pile body
The web in the shaped steel joint 16 is fixed by welding,
The angle θ of the straight line connecting the center of the intermediate pile body 15 and the web of each T-shaped steel joint 16 is determined by the angle determined by the curvature of the cylindrical well pipe to be built.

1 to 4 show a landslide suppressing well 12 according to the first embodiment of the present invention built on the ground of a landslide area, the well 12 penetrating a slip surface 1 of the ground. Inserted to the prescribed depth of insertion in the base 13,
The rooting depth is the upper ground 1 above the slip surface 1.
The depth is set so as to exert a sufficient consolidation force so that the well 12 does not incline in the slipping direction due to the horizontal force acting when sliding.

Explaining the structure of the well 12, the many vertical holes 2
Are excavated so as to be smoothly lined up at regular intervals, the steel piles 3 with joints are inserted into the vertical holes 2, and the steel piles 3 with joints are also inserted.
The slit pipe joint case in is arranged so as to be located in the circumferential direction at the planned Izutsu construction position, and between the hole wall of the vertical hole 2 and the steel pile 3 with joint, a hardenable grout material 4 such as mortar or concrete. Is filled in the intermediate vertical hole 5 which is excavated so as to overlap the adjacent vertical holes 2,
The intermediate steel pile 6 with a joint is inserted, and the flange side portions of the T-shaped steel joints 16 on both sides of the intermediate steel pile 6 with a joint are inserted into the slit pipe joint holder of the steel pile 3 with a joint and meshed with each other. Further, a hardened grout material 7 such as mortar or concrete is filled between the hole wall of the intermediate vertical hole 5 and the intermediate steel pile 6 with joint, and the hardenability of mortar or concrete or the like is set in the slit pipe joint 10. The grout material 11 is filled.

Further, a steel stiffening member 17 made of H-shaped steel is inserted into each pile body 9 and the intermediate pile body 15 over a range of L ₁ upward from the slip surface 1 and L ₂ downward from the slip surface 1. The stiffening member 17 is embedded in a curable grout material 18 such as mortar or concrete filled in the pile body 9 and the intermediate pile body 15.

The cross-sectional structure of the well 12 may be the same over the entire length in the depth direction, but as in the above-described embodiment, the cross-section rigidity of the well 12 in the upper and lower predetermined sections sandwiching the slip surface 1 has a cross section of other portions. If it is set to be larger than the rigidity, the well can be constructed economically with a reasonable sectional rigidity.

FIG. 7 shows a part of the landslide suppressing well cylinder 12 according to the first embodiment of the second invention, in which the adjacent intermediate steel piles 6 with joints are bored so as to overlap with each other. For slit pipe joint 10 of steel pile 3 with joint,
The flange side portion of the steel intermediate joint 8 made of I-shaped steel is inserted, but the other configurations are the same as those of the well 12 according to the embodiment of the first invention.

FIG. 8 shows a part of the landslide suppressing well 12 according to the second embodiment of the second invention, in which two slit pipe joints 10 are welded to both side surfaces of the steel pile body 9. The steel piles 3 with joints are fixed to each other, and two sets of the slit pipe joints 10 facing each other in the adjacent steel piles 3 with joints are connected to the flange side of the steel intermediate joint member 8 made of I-shaped steel. Although the portion is inserted, the other structure is the same as that of the first embodiment of the second invention.

FIG. 9 shows a part of the landslide suppressing well 12 according to the third embodiment of the second invention, which is composed of two I-shaped steels arranged between adjacent steel piles 3 with joints. The widthwise central portion of the web in the steel intermediate joint member 8 is connected by a steel connecting plate 19 fixed to them by welding, but the other configurations are the same as those of the second embodiment of the second invention. .

FIG. 10 shows a part of the landslide suppressing well 12 according to the fourth embodiment of the second invention, which is composed of two I-shaped steels arranged between adjacent steel piles 3 with joints. Two steel connecting plates 19 arranged at intervals in the web width direction are fixed by welding to an intermediate portion of the steel intermediate joint member 8 in the width direction of the web, and the two connecting plates 19 make two steel connecting plates. The other configuration in which the intermediate joint member 8 is connected is the second
This is similar to the second embodiment of the invention.

In the case of the second embodiment to the fourth embodiment of the second invention, it is possible to remarkably increase the connection strength between the adjacent steel piles with joints. Further, in the case of the third embodiment and the fourth embodiment of the second invention, the joint strength of the adjacent steel piles 3 with joints in the radial direction of the well can be significantly increased.

Next, an example will be described in which the method of the present invention is carried out to construct the landslide suppressing well 12 according to the first embodiment of the present invention.

First, as shown in FIG. 11, a digging method that does not use muddy water, for example, a casing-combined digging machine is used to form a vertical hole 2 penetrating a slip surface 1 in the ground of a landslide area. Since the ground is fragile in the landslide area, if the drilling method using muddy water is adopted, the water that escapes from the hole may accumulate near the slip surface and induce landslides. Is preferably adopted.

Next, the slit pipe joints 10 of the steel piles 3 with joints are arranged in the vertical holes 2 so as to be positioned in the circumferential direction of the planned Izutsutsu construction position, and the length of one steel pile 3 with joints is constructed. If the length of the well is shorter than the length of the well, the steel pile 3 with a joint is added by welding into the vertical hole 2 and then the hardenable grout material 4 is inserted between the hole wall of the vertical hole 2 and the steel pile 3 with a joint. Is injected and filled to build the pillar body 20.

Next, as shown in FIG. 12, the sliding surface 1 is located at a position distant from the pillar 20 in the circumferential direction of the planned Izutsu construction position.
After the vertical hole 2 penetrating the hole is drilled by a drilling method that does not use muddy water as described above, as shown in FIG. 13, the steel pile 3 with a joint is inserted into the vertical hole 2 and the hardenable grout is inserted. The material 4 is injected and filled, the second pillar 20 is built as described above, and the pillars 20 are successively built in the same manner.

Next, as shown in FIG. 14, the hardenable grout material 4 in the slit pipe joint 10 on the opposite side of the adjacent steel piles 3 with joints is excavated by a rotary impact tool (percussion drill) having a cross bit. Then, a space 21 is provided in the slit pipe joint 10, and then an excavator having a guide member that is fitted into the slit pipe joint 10 on the opposite side of the adjacent steel piles 3 with joints.
An intermediate vertical hole 5 that is close to the adjacent slit pipe joint 10 and overlaps the adjacent vertical holes 2 is formed.

Next, the intermediate steel pile 6 with a joint is inserted into the intermediate vertical hole 5, and the T-shaped steel joints 16 on both sides of the intermediate steel pile 6 with a joint are inserted into the slit pipe joint 10 of the steel pile 3 with a joint. However, when the length of one intermediate steel pile 6 with a joint is shorter than the length of the well tube to be built, the intermediate steel pile 6 with a joint is added by welding to the inside of the intermediate vertical hole 5 and the slit pipe joint 10. insert. When inserting the intermediate steel pile 6 with a joint, if the vibrator is attached to the intermediate steel pile 6 with a joint, insertion can be performed easily.

Next, as shown in FIG. 4, a curable grato material 7 is injected and filled between the hole wall of the intermediate vertical hole 5 and the intermediate steel pile 6 with a joint, and a T-shaped steel joint 16 is inserted into the slit pipe. The curable grout material 11 is injected and filled into the manufactured joint 10 and, as described above, the intermediate columnar body 22 including the intermediate steel pile 6 with the joint and the curable grout material 7 is provided between the adjacent columnar bodies 20. , The landslide prevention well 12 is built, and then the concrete plate 2 is attached to the upper end of the well 12 if necessary.
Install 3 in one.

When constructing the wells according to the first to fourth embodiments of the second aspect of the invention, the vertical holes 2 are overlapped and bored to construct the continuous columnar body 20, and then the steel with adjacent joints is constructed. An intermediate hole 24 is formed between the opposing slit pipe joints 10 in the pile 3 to form a space, and the grout material in the slit pipe joints 10 is excavated and removed. After inserting the intermediate joint member 8 over the joint 10, the curable grout material is injected and filled into the intermediate hole 24 and the slit pipe joint 10.

After carrying out the present invention to construct a well, the earth and sand in the well can be excavated and removed, or the earth and sand in the well can be left unexcavated.

〔The invention's effect〕

Since the present invention is configured as described above, it has the following effects.

Due to the meshing of the joints, a large number of steel piles 3 with joints arranged so as to penetrate through the slip surface 1 of the ground in the landslide area and the intermediate steel piles 6 with joints interposed between the adjacent steel piles 3 with joints The slit pipe joints 10 of the steel piles 3 with joints and the steel intermediate joint members 8 interposed between the adjacent steel piles 3 with joints are connected by meshing and are mutually connected. Steel piles with connected joints 3
And the intermediate steel pile with joint 6 are hardened grout materials 4, 7
The steel piles 3 with joints and the steel intermediate joint members 8 that are embedded in and integrated with each other, or are connected to each other are embedded in the hardenable grout material 4 and integrated to prevent landslides with large cross-sectional rigidity. Since the well cylinder 12 is configured, the well cylinder 12 can be strengthened against a large bending moment and a large shearing force due to earth pressure of the upper ground 14, and the well cylinder 12 can surely suppress the landslide, and further insert the joint. By filling the curable grout material 11 into the slit pipe joint 10 described above, the cross-sectional rigidity of the well 12 can be further increased.

Further, by making the cross-sectional rigidity of the well 12 in a predetermined vertical section sandwiching the slip surface 1 of the ground larger than the cross-sectional rigidity of other portions of the well 12, the cross-sectional rigidity of the portion of the well 12 on which a large external force acts is increased. As it gets bigger,
Since the cross-sectional rigidity of the portion of the well 12 that is subjected to a small external force can be reduced, the well 12 can be economically constructed with a cross-sectional rigidity of a rational level against the external force.

Furthermore, according to the method for constructing a well for landslide prevention of the present invention, excavation of a vertical hole, insertion of a steel pile 3 with a joint, insertion of an intermediate steel pile 6 with a joint or a steel intermediate joint member 8, and a hardenable grout material. Since all of the injection and filling can be performed from the ground, safety measures such as the conventional deep foundation work are not required, and the landslide prevention well can be constructed with high efficiency.

[Brief description of drawings]

1 to 4 show a landslide suppressing well tube according to an embodiment of the first invention, in which FIG. 1 is a vertical cross-sectional side view showing an installed state of the well tube, and FIG. 2 is A in FIG. -A line enlarged sectional view, FIG. 3 is an enlarged sectional view taken along line BB of FIG. 1, and FIG. 4 is a cross-sectional plan view showing an enlarged part of FIG. FIG. 5 is a plan view of a steel pile with a joint, FIG. 6 is a plan view of an intermediate steel pile with a joint, and FIG. 7 is a cross-sectional plan view showing a part of a well tube according to the first embodiment of the second invention. 8 is a cross-sectional plan view showing a part of a well according to the second embodiment of the second invention, FIG. 9 is a cross-sectional plan view showing a part of a well according to the third embodiment of the second invention, and FIG.
The drawing is a cross-sectional plan view showing a part of the well according to the fourth embodiment of the second invention. 11 to 14 are cross-sectional plan views showing the order of construction of the landslide suppressing wells of the present invention. In the figure, 1 is a slip surface, 2 is a vertical hole, 3 is a steel pile with a joint, 4 is a hardenable grout material, 5 is an intermediate vertical hole, 6 is an intermediate steel pile with a joint, 7 is a hardenable grout material, 8 is a Steel intermediate joint member, 9 steel pile body, 10 slit pipe joint,
11 is a curable grout material, 12 is a well, 13 is a base,
4 is an upper ground, 15 is a steel intermediate pile main body, 16 is a T-shaped steel joint, 17 is a steel stiffening member, 18 is a hardenable grout material,
19 is a steel connecting plate, 20 is a column, and 22 is an intermediate column.

Front page continued (72) Inventor Satoshi Yamamoto 5-9-1 Nishihashimoto, Sagamihara City, Kanagawa Prefecture, Nippon Steel Corporation Sagamihara Technical Center (72) Inventor Yasuo Sasaki 2-3-6 Otemachi, Chiyoda-ku, Tokyo No. Shin Nippon Steel Co., Ltd. (72) Inventor Hiroshi Suzuki 3-4 Ichigaya Sadohara-cho, Shinjuku-ku, Tokyo Inside Sabo / Landslide Technology Center (72) Ino Onzo 1-13 Nishishinjuku, Shinjuku-ku, Tokyo No. 12 Nishishinjuku Showa Building inside Teishi Ishii Industry Co., Ltd.

Claims (4)

[Claims] 1. A large number of vertical holes 2 penetrating a slip surface 1 are bored so as to be arranged in a circle at intervals in the ground in a landslide area, and steel piles 3 with joints are inserted into the vertical holes 2. In addition, a hardenable grout material 4 is filled between the vertical hole 2 and the steel pile 3 with a joint, and an intermediate steel pile with a joint is provided in an intermediate vertical hole 5 provided so as to be connected to an adjacent vertical hole 2. 6 is inserted, and the intermediate steel piles 6 with joints and the steel piles 3 with joints on both sides thereof are connected by meshing of the joints, and the intermediate vertical holes 5
A well for preventing landslides, in which a hardenable grout material 7 is filled between the joint and the intermediate steel pile 6 with a joint. 2. A large number of vertical holes 2 penetrating a sliding surface 1 are formed in the ground of a landslide area so as to be arranged in a circle and connected to each other. A steel pile 3 with a joint consisting of a slit pipe joint 10 fixed to both side faces is inserted, and a curable grout material 4 is filled between the vertical hole 2 and the steel pile 3 with a joint, with adjacent joints. Both sides of the steel intermediate joint member 8 are meshed with the slit pipe joint 10 of the steel pile 3, the intermediate joint member 8 is embedded in the curable grout material, and the slit pipe joint 10 is provided in the slit pipe joint 10. Curable grout material 11
Izutsutsu for landslide prevention filled with. 3. The landslide suppressing device according to claim 1 or 2, wherein the cross-sectional rigidity of the well pipe in a predetermined vertical section sandwiching the slip surface 1 of the ground is larger than the cross-sectional rigidity of other portions of the well pipe. Izutsu. 4. A steel pile main body 9 and both side surfaces of the pile main body 9 are formed by arranging vertical holes 2 penetrating the slide surface 1 in the landslide area in the circumferential direction of the planned construction position of the Izutsu. A steel pile 3 with a joint consisting of a slit pipe joint 10 fixed so as to extend is inserted into each vertical hole 2 and the vertical hole 2
Slit pipe joint 1 of adjacent steel piles 3 with joints filled with a curable grout material 4 between the steel piles 3 with joints
A method of constructing a well for landslide prevention in which 0s are meshed with each other or are connected via a steel intermediate joint member 8 and the hardenable grout material 11 is filled into the slit pipe joint 10.