JPH10280398A - Landslide preventive steel pipe pile having box-shaped truss or ring truss type pile head connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pile head connection head capable of providing a large yielding bending stress at a satisfactory extent even at the point of time wen sliding deformation has progressed in a pile head connection structure of steel pile driving work. SOLUTION: A landslide preventive steel pipe pile having a truss type pile head connection structure is provided with a plurality of steel pipe piles 26, a plurality of cylindrical cap structures 23 connected to the top of the pile head of the steel pipe pile 26 and a plurality of recessed onsite welding joints 24 which are welded and connected to the side surface of this pile cap structure 23 and comprises a plurality of pile head connection materials 25 incorporated into the truss type between these onsite welding joints 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to the construction of deterrent piles, which are often used as landslide countermeasures against landslides, dams and roads, in deterrent structures such as kui, shaft and anchor works. This is related to landslide deterrence works that attempt to counter landslide thrust with rigid force. This is an area where the establishment of future technology is desired.

[0002]

[Prior Art] There are two types of pile work: driving method and insertion method.
The former method is a method of hitting and driving the pile head in the same way as a foundation pile.In order to prevent landslides, it is necessary to drive into the foundation rock and a movement that causes a sudden collapse of part of the landslide When it is shown, it is better to limit to temporary construction work for the purpose of emergency earth retaining, the latter is a method of excavating the planned depth up to the rooting part by large diameter boring and inserting pile material into the hole by drilling After that, the inside and the outer periphery are carefully checked with concrete or mortar. Pile materials include concrete and steel (H-shaped steel, steel pipe).

[0003] The effect of the pile depends on the installation position, the properties of the soil mass, and the like. In the tension zone at the head of the landslide, a cantilever beam is used to receive the load of the sliding mass behind, which is a so-called bent pile. Is supported by the mass of soil, the strength of the mass is sufficient,
When the pile is considered to be rigid, the pile becomes a so-called shear pile. However, in many cases, the landslide mass is a collapsed soil layer, and the landslide mass is deformed and becomes a so-called elastic pile.

Also, the arrangement of the piles should be perpendicular to the direction of the landslide operation as much as possible. However, since the landslide mass is soft and there is a risk of falling out, design it so that it does not exceed a maximum of 4 m, and determine the required number of piles,
The allowable strength is calculated by dividing the landslide planning deterrent.

[0005] For this reason, the pile structure includes not only reinforced concrete piles and steel pipe piles, but also composite piles, and the connection of the pile heads has a rigid frame structure in which rigid connection is made with reinforced concrete to prevent erosion between the piles. FIGS. 1, 2 and 3 show a prior art example of a landslide-preventing steel pipe pile of rigid rigid structure type.

Here, FIG. 1 is a general view of a truss-shaped pile head connection structure of a landslide prevention steel pipe counterpart according to a conventional example, FIG. 2 is a truss-type pile head connection rigid connection structure diagram, FIG. 3 is a side view of a truss-type pile head connection rigid connection structure. FIG. 4 is an embodiment diagram of a landslide prevention steel pipe piler according to a conventional example.

[0007] This prior art is a landslide prevention steel pipe pile with a tension tie rod inserted and installed by a pile construction method in a landslide compression zone, in a very small number in the technical field related to landslide prevention. At the initial stage of sliding, a steel pipe pile that receives shearing force on the sliding surface, and the pile head of the steel pipe pile and the connecting member of the H-shaped steel are connected from above and below the pile head with the connecting member receiver of the disc steel with a reinforcing plate. Hold it down, hold it down, assemble it into a truss shape at the pile head, connect the pile head rigidly, eliminate the deformation with tension tie rods, make the steel pipe pile rigid,
A truss-type rigid connection structure with truss-type pile heads and so-called shear piles, and a pile-head-connection rigid structure with multiple truss-type pile heads connected horizontally on the ground surface A truss type is connected to the pile head, and the landslide mass below this is soft and supplements the deterrent of piles where there is a danger of hollowing out (where there is a multi-level slip). A landslide prevention steel pipe piler with a tension tie rod of a rigid rigid frame structure characterized by comprising a pile head connection structure assembled in an H-shaped steel truss-type for preventing erosion of steel.

This prior art pile head connection structure is a pile head connection rigid connection structure composed of a steel pipe pile head, an H-shaped steel connection member, and a connection member receiver of a disk steel with a reinforcing plate. It is a simple pile head connection rigid structure to supplement the deterrent force of the pile by simply adding the deterrent force of the pile of the rear pile and the primary pile in the place where there are multiple slips. To ensure that each stake of the front stake and the back stake for secondary slip control is safe even if primary slip or secondary slip occurs one by one.
This is an emergency simple rigid connection structure that transmits shear forces to each other at the pile head and complements the shear resistance.

However, the front pile and the rear pile are connected firmly to the pile head, and the bending moments of both piles in the deep underground are all 9 at the pile head.
By changing the direction to 0 ° and transmitting smoothly to both piles, the deformation is exemplarily cleaned, the bending moment acting on the piles is reduced, and the horizontal rigidity of the piles is basically increased, It is not intended to increase the horizontal resistance of the pile.

Furthermore, the conventional rigid connection structure of the pile head of the prior art, whether it is the primary slip or the secondary slip, if only one of the slips, it can withstand the initial stage of the slip, but the pile head can withstand the initial slip. Even if a tension tie rod is attached to the stake, if the slide advances and the pile is deformed, especially if the pile head undergoes rotational deformation, the deformation of the front and rear stakes will be horizontal before and after staggering. Due to the large difference in the bearing force, the pile heads are greatly different, and the shear force is not transmitted to each other by the anti-head, and the addition of the deterrent force between the front and rear piles cannot be expected. The pile has a large deformation, the bending moment increases, and the pile does not function as a shear pile.

At present, a method of rigidly connecting the front and rear piles to each other is not adopted in principle, and there is a great need to withstand the bending moment when deformation occurs. There are no cases where the front and rear piles are rigidly connected to the pile head except in special cases, and this case is a very special case that was implemented urgently to suppress primary slip and secondary slip simultaneously. This is an example, and there are only two locations in Japan, and they are simply connected simply and quickly.

[0012] The pile body 16 of the conventional landslide prevention steel pipe piler
Is a rigid section 20 having a thick wall and a maximum cross-sectional area composed of the H-section steel 8, the steel pipe pile 9, the reinforcing steel pipe 10, and the poured concrete 11, and is very expensive and very uneconomical.

Next, the secondary slip surface 18 is almost in a balanced state at present, and if the primary slip surface 17 is moved and the lower earth mass is removed, the secondary slip surface is prevented. The safety factor is less than 1.0, which is dangerous.

[0014]

[Problems to be solved by the invention]

(1) The pile head connection rigid structure composed of the steel pipe pile head, the connection member of the H-shaped steel, and the connection member of the disk steel with the reinforcing plate is H
The end of the connecting member of the mold steel is rigidly connected to one side of the cylinder of the steel pipe pile head,
It is not rigidly connected to one side of the other cylinder, but is pinched with disc steel with a reinforcing plate from above and below the pile head and pressed down, but with a tension tie rod attached. However, it can withstand only the initial shearing force of sliding, and is very weak to the bending moment when deformation (especially rotational deformation) occurs due to sliding, and cannot be resisted. When a pile comes out, a bending moment acts on the pile, and the pile head of the steel pipe pile breaks.

(2) In the truss type pile head connection rigid connection structure, even if a tension tie rod is attached, there is no deformation in the initial stage of sliding, only horizontal force acts, and a shear force acts on the pile. Is considered to be rigid, but when the sliding progresses and deformation (especially rotational deformation) comes out, a large bending moment acts on the pile and the pile becomes rigid. The pile head connection is no longer rigid because it is no longer considered to be a pin connection, and the steel pipe pile pile head is peeled off.

(3) The truss-type rigid connection structure of the pile head has a large bending property even if a tension tie rod is attached to the pile when deformation (especially rotation deformation) occurs due to sliding. Moment acts, and a bending stress concentration is generated on one side of the cylinder of the pile head, and the pile head of the steel pipe pile immediately breaks down.

(4) Therefore, the truss-type pile head connection rigid structure hardly resists the bending moment generated by the landslide even if the magnitude of the force is not large.

(5) Further, even if a bending moment is generated on the pile head connection structure constructed in the same truss shape of H-shaped steel, it is hardly transmitted to the pile head.

(6) Further, as in the case of a pile head reinforcing pile connected by an underground beam which is usually called a rigid rigid frame structure, a sufficiently strong and smooth bending moment is transmitted at the pile head, and the It does not do. The pile head connected by this underground beam is a non-truss-type pile head connection rigid structure composed of an outer shell steel tube, an underground beam reinforcing bar, and a filling concrete.

(7) A truss-type pile head constructed by constructing a truss-type connecting member of the same H-shaped steel for a plurality of steel pipe pile heads with the same pile head connection rigid structure. In order to fix the pile with the axial force of the truss-type pile head connecting material, the pile structure should be as perpendicular to the landslide operation direction as possible, but the piles should be arranged at regular intervals. If the piles need to be dense, the piles must be spaced widely to prevent the immovable bedrock from breaking as a bird, and high pile strength is required. The pile head connection structure is also required to have high axial strength, and even with a tension tie rod, there is a large amount of rotational deformation of the pile even in the initial stage of sliding, and the pile must be rigid. Shear stiffness is required to allow The shear stiffness must be very large, and the more the steel structure, the larger the thickness of the pile and the pile head connection structure assembled in the same truss type and the larger the cross-sectional structure of the maximum cross-sectional area, Very uneconomical.

(8) If the landslide mass is installed in a place where the landslide mass is soft and slips through (in a place where there are multiple slips), no ground reaction force can be expected on the piles within that range. Very large ground reaction force is required for piles outside this range, and very high axial force strength is also required for the pile head connection structure constructed in the same truss type. However, in order to prevent the landslide mass from working, it is necessary to take a sufficiently large shear resistance that does not allow deformation, so the shear rigidity must be very large,
The more the steel structure is used, the more the pile and the truss-type pile head connection structure have a very thick wall and a large cross-sectional area, which is very uneconomical.

(9) Further, in the pile head connection structure assembled in the truss type, when the sliding progresses and the deformation starts, a large bending moment acts on the pile, whereby the truss type assembly is formed. A large fixed bending moment also acts on the pile head connection structure, but the direction is the direction of the slanted material and the direction of twisting of the pile head connection structure assembled in the same truss type. A large torsion moment is simultaneously generated in the chord member of the pile head connection structure assembled in the truss type, and the H-shaped steel has a warp deformation characteristic with respect to the torsion moment. A large relative warp deformation occurs with the lower chord material, and the slanted chord material leads the warp deformation, so that the pile head connection structure assembled in the same truss type has to be warped in the horizontal direction, As well as the rigid frame structure The torsion moment is combined with the large bending moment, the warp is deformed. First, the rigid connection part is twisted and does not withstand torsion. The truss type pile head connection structure is the pile head. It can hardly resist the bending moment. This is a major problem with the rigid frame structure composed of an H-shaped steel in a truss shape. In summary, the problem is that the H-shaped steel is warped.

(10) According to the results, a pile head connection structure composed of a steel pipe pile head, a connection member of H-shaped steel and a connection member of a disk steel with a reinforcing plate, and a pile head connection rigid structure. Therefore, for a plurality of steel pipe pile heads, a truss-type pile head connection structure composed of a truss-type connecting member made of the same H-shaped steel is provided at the pile head on the ground surface. Is
There is no deformation, only in the initial stage of sliding, the shear force is transmitted to the pile head to make the pile rigid, and it can only resist the horizontal force of the landslide.

(11) In order to prevent erosion between piles, the steel pipe pile has a truss-type pile head connection structure and a pile head connection rigid structure attached to the pile head. As a piler, the landslide mass is deterred from starting to move.In order to increase the deterrent of the piler, the pile head has a pile head connection structure and a pile head connection rigid connection structure. It does not prevent the landslide mass from starting to move. When the landslide thrust is very strong compared to the strength of the pile, or when the landslide thrust is a weak force, the landslide mass is soft (there is a place with multiple slips). When there is no resistance and no deterrent is exerted between the pile and the pile head connection structure, the pile head connection rigid structure does not play any role of transmitting the shear force and does not use anything. This is to prevent erosion between piles.

Although the pile and the landslide mass are slightly allowed to deform (rotational deformation is allowed to be large), the pile head connection structure and the pile head connection rigid structure not only have the elastic strength but also the yield strength. The pile work has been increased to increase the deterrent, and the landslide has been surely suppressed. The connection structure and its pile head connection rigid structure have utility.

In summary, the pile head connection structure and the pile head connection rigid connection structure are for preventing erosion between piles.

Therefore, in the present invention, in the connection of the pile head of the steel pipe piler, the bending moment generated on the pile head connection structure of the H-shaped steel assembled in the truss type is smoothly transmitted to the pile head. However, even if deformation due to sliding comes out, there is no warpage deformation, the pile head becomes a rigid rigid frame structure that does not twist or bulge, and the steel pipe pile with the pile head connection rigid structure becomes a so-called bending pile In order to minimize the bending moment that occurs, the bending moment is simultaneously and smoothly transmitted to both sides of the pile head cylinder, the compressive stress and the tensile stress are equal on both sides of the pile head cylinder, and the deformation is also It is uniform, the pile head does not twist or bulge, and the box-shaped section steel has a rigid rigid frame structure without warpage of the pile head, greatly reducing the bending moment that occurs. The truss-type pile head connection structure and the pile head connection rigid connection structure must be provided, and since it is a box-shaped cross-sectional steel, it has three-dimensional strength characteristics and withstands torsional moment, It is an object of the present invention to provide a truss-type pile head connection structure and a pile head connection rigid connection structure capable of obtaining a sufficiently large yielding bending strength even at the time when the deformation of sliding has progressed.

[0028]

SUMMARY OF THE INVENTION A landslide-preventing steel pipe pile having a truss-type pile head connection structure according to the present invention comprises a plurality of steel pipe piles and a plurality of cylindrical pile cap structures connected to the pile tops of the steel pipe piles. And a plurality of concave field welded joints which are welded and connected at an angle to the side surface of the pile cap structure, and the gap between the pile cores between these field welded joints is aligned and incorporated into a truss type. And a plurality of box-shaped steel pile head connecting members. In addition, landslide prevention steel pipe piles having a ring truss type pile head connection structure,
A plurality of steel pipe piles arranged in a plurality of rows, a plurality of cylindrical pile cap structures connected to the pile tops of the steel pipe piles, and a plurality of concave field weldings which are welded and connected at an angle to the sides of the pile cap structure. It comprises a joint and a plurality of box-shaped steel pile head connecting members which are aligned and incorporated into a ring truss type with respect to the displacement between the pile cores between these field welded joints.

Incidentally, the plurality of box-shaped steel pile head connecting members are:
It forms a polygon of a regular pentagon or more, and the angle between the outer chord material and the oblique chord material is 1/3 of the inner angle.

The cylindrical pile cap structure comprises a cylindrical main body having a relatively large cross section, an upper small diameter having two kinds of diameters for fixing the pile head, ie, a cut pipe having the same diameter as the pile head, and a lower large diameter pipe. A cut pipe having a diameter into which a pile head is inserted, three horizontal flat steel plates welded to the cylindrical main body, that is, an upper closing flat steel plate, an intermediate flat steel plate interposed between the cut pipes, and And a lower flat steel plate having an insertion hole for the pile head.

In addition, the concave type field welding joint is vertically divided into two parts so that the end of the pile head connecting member is inserted and aligned with the gap between the pile cores. After the angle is adjusted to the mold pile cap structure, the entire circumference is finally welded only from above to be integrally welded.

The method of constructing the landslide prevention steel pipe pile is as follows.
At the site, before inserting the steel pipe pile into the pile hole of the landslide ground, first insert and weld the cylindrical pile cap structure to the pile head of the steel pipe pile, and then connect the box-shaped steel pile head connecting material to the concave field weld joint. It is characterized in that it is inserted and positioned relative to the gap between the cores of the piles, and the concave field welding joint is angle-aligned and welded to the cylindrical pile cap structure from above all around. .

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION

(Claim 1) A truss-type pile head connecting structure of box steel according to the present invention comprises a plurality of cylindrical pile cap structures, a concave field welded joint having a plurality of arc joining surfaces, and a plurality of box-shaped steel piles assembled in a truss shape. It is composed of a head connection material and a plurality of steel pipe piles.

With a plurality of cylindrical pile cap structures and a plurality of box-shaped steel pile head connecting members assembled in the same truss shape,
The steel pipe pile pile heads are firmly fixed to the ground surface of the moving layer,
The fixed bending moment is smoothly transmitted from the plurality of steel pipe pile pile heads to the same pile body via the plurality of box-type steel pile head connection members assembled in the truss type, and the truss type rigid connection and rigid connection In order to greatly reduce the bending moment acting on the steel pipe pile body deep underground due to the ramen effect, [1] the ends of the pile head connecting members of a plurality of box-shaped steels assembled in the same truss type have a cylindrical pile cap structure. With a set of concave field welded joints having a plurality of arc-jointed surfaces, it is possible to easily and quickly perform field welding (fillet welding or piercing butt welding) on a plurality of cylindrical pile cap structures only from above. The entire ends of the piles are connected to each other without any alignment between the cores of the piles. Easy connection and rigid connection In order to prevent the ends of the plurality of box-shaped steel pile head connecting members assembled in the same truss shape from the steel pipe pile pile head having the cylindrical pile cap structure from being bent at all, the concave-shaped field welded joint is By connecting one set to a box shape that is one size larger and double-layered on the outer shell side of the end of the pile head connection material of the same box type steel, sandwiching it, and welding on site only from above, the connection rigid connection structure By making the wall thickness, cross-sectional area and second moment of area extremely large and connecting and stiffening significantly with high strength, the pile heads of multiple steel pipe piles composed of multiple cylindrical pile cap structures , Box-type steel truss-type pile head connection structure can be easily and quickly constructed only from above.
[2] By this construction method, the truss type pile head connection structure of the box type steel is composed of a plurality of cylindrical pile cap structures on the surface of the landslide moving layer easily and quickly. [3] Furthermore, a plurality of cylindrical pile cap structures apply a fixed bending moment from the plurality of steel pipe pile pile heads to the same pile body. Because of the very smooth transmission, the box-type steel truss-type pile head connection structure is used for the landslide-preventing steel pipe pile with the box-type steel truss-type pile head connection structure. In this case, [4] the box-shaped steel of the truss-type pile head connection structure of the box-shaped steel has very little horizontal deformation and has no tertiary deformation. With original strength characteristics Until the point of yielding, the deformation is normal and exhibits a typical P-δ curve, and stress is transmitted smoothly as usual, so that stress transmission is very normal and sufficiently smooth, [5] The box steel of the box steel truss-type pile head connection structure does not collapse under the shear stress from the plurality of steel pipe pile heads, nor does it collapse under the bending stress until it yields. By transmitting the combined bending stress and the torsional stress, the fixed bending moment can be transmitted sufficiently smoothly on the ground surface of the transfer layer. [6] The truss-type pile head connection structure of the box-shaped steel slides out. In addition to the initial stage, even if sliding occurs and deformation occurs, the deformation is regarded as a normal and exemplary P-δ curve, and [7] the box-type steel truss-type pile head connection structure has a soft hollow portion. (There is a place where there are multiple slips) When installed on a high-risk landslide-moving ground, the piles in that area cannot be expected to react to the ground, but they are arranged in a truss-shaped dried bird-like shape, and are arranged in parallel with the landslide laterally in a truss-type. Even if deformation occurs due to the truss-type rigid connection and the continuous rigid connection rigid frame effect between four consecutive front and rear and right and left steel pipe piles, the deformation of the plurality of steel pipe pile heads is very small from the beginning. Even in the deep underground where the landslide surface is present, the deformation of the pile body in the vertical and horizontal direction of the landslide is also restrained to the same rigidity, and the deformation of the pile body is reduced to the same level over the deep underground. When the ground reaction force is reduced to the same value and [8] the plurality of steel pipe piles are inserted and installed according to the truss-type pile head connection structure of the box steel, the pile arrangement of the plurality of steel pipe piles is a bird-like arrangement. Therefore, the horizontal load of the pile differs greatly, and the horizontal load of the rear pile is large. Therefore, the bending moment acting on the back pile is greatly reduced by the truss-type rigid connection and the continuous rigid connection rigid frame effect because the bending moment acting on the pile body greatly differs over the deep underground. Therefore, the bending moment acting on the front pile is also equalized and greatly reduced,

[9] In the box-type steel truss-type pile head connection structure, the plurality of steel pipe pile-heads are connected and rigidly connected at four ends of the box-type steel truss-type pile head connection structure. And that the deformation of the plurality of steel pipe piles is restrained equally to the rigidity in the horizontal and vertical directions of the landslide by the truss type continuous rigid connection ramen effect and becomes smaller, and furthermore, the truss type pile head of the box steel is further reduced. Since the deformation of the connection structure is a normal one that exhibits a typical P-δ curve, the fixed bending moment of the pile head in the horizontal direction on the ground surface of the landslide transfer layer is very normally and sufficiently smoothly. To communicate,
[10] The truss-type pile head connection structure of the box-type steel is such that the pile arrangement of the plurality of steel pipe piles is a bird-like arrangement in the horizontal direction of the landslide, so that the horizontal load force of the piles is slightly different in the horizontal direction. In parallel, the fixed bending moment of the pile head in the horizontal direction of the landslide is reduced in parallel by sharing in parallel, and the fixed bending moment of the pile head in the horizontal direction of the landslide is also reduced in parallel by greatly reducing the The fixed bending moment of the head is greatly reduced. [11] In addition, the box-type steel truss-type pile head connection structure is made of box-type steel, which reduces axial force, bending moment and torsion moment. And the box-shaped steel pile head connecting member is assembled in a truss shape, and the plurality of steel pipe pile pile heads having a cylindrical pile cap structure according to the invention are connected to each other by a three-dimensional rigid frame. Truss type A sealing rating point structure, and, 4 the plural steel pipe pile pile head of truss pile head connection structure of the box-steel
The landslide of the same steel pipe pile pile head with strong rigidity of four front, rear, left and right parallel to the landslide horizontally and horizontally in a truss type by being concentrated and connected rigidly at the end of the book The steel pipe pile heads are fixedly connected to the truss type on the ground surface of the transfer layer by concentrating and connecting the steel pipe piles horizontally and horizontally in a horizontal and horizontal direction. Because the connection rigid structure of the pile head is a strong pile cap structure, it is strongly reinforced and protected so that the same plurality of steel pipe pile heads are not lifted. [12]
The truss-type pile head connection structure of the box-type steel has a truss-type rigid connection and rigid-frame effect, and the pile cap structure has a smooth cross-sectional stress transmission effect, which reduces the bending moment acting on the pile body deep underground in the vertical direction. Smoothly transmitted, greatly equalized and reduced, all of the steel pipe piles were changed from so-called shear piles to bent piles, and the bending moment acting on the steel pipe pile bodies deep underground was greatly increased To
It significantly increases the horizontal resistance of the pile.

[13] The rigidity of the plurality of steel pipe piles changes from a so-called shear pile to a bent pile, and the plurality of steel pipe piles changes from free pile head to fixed pile head, resulting in high rigidity. By reducing the acting section force and greatly increasing the horizontal resistance of the pile, the cross section of the plurality of steel pipe piles is thinned and the cross section of the small cross section is relatively small, so that the plurality of steel pipe piles are inexpensive. In any case, the landslide prevention steel pipe pile having the box-type steel truss-type pile head connection structure of the present invention is economical.

(Claims 2 and 3) Another ring truss-type pile head connecting structure of box-shaped steel according to the present invention comprises a plurality of cylindrical pile cap structures, a concave type field welded joint fitting having a plurality of arc joining surfaces, and a ring. It is composed of a plurality of box-shaped steel pile head connecting members assembled in a truss shape and a plurality of steel pipe piles.

The plurality of box-shaped steel pile head connecting members are polygons having a regular pentagon or more, and the angle between the outer chord member and the oblique chord member is one-third of the inner angle. Ring truss type.

Then, the plurality of steel pipe pile heads are firmly fixed to the ground surface of the moving layer with a plurality of cylindrical pile cab structures and a plurality of box-shaped steel pile head connecting members assembled in the ring truss type, The fixed bending moment is smoothly transmitted from the piles of steel pipe piles to the pile body, and the ring truss-type rigidity and continuous rigidity ramen effect allows the pile piles and piles of the steel pipe piles to slide. [1] A plurality of box-shaped steel pile heads assembled in the same ring truss type so as to integrally resist the sliding motion in a tubular shape and greatly reduce the bending moment acting on the steel pipe pile body deep underground Matching the end of the connecting material to the intersection angle with the plurality of cylindrical pile cap structures of the invention, with a set of concave field welded joints having a plurality of arc joining surfaces, for a plurality of cylindrical pile cap structures, Easy and quick Welding of multiple box-type steels that are assembled in the same ring truss type is performed only from above by field welding (full-round welding or through-butt butt welding) without any adjustment of the gap between pile cores. The end of the pile head connection material is easily connected and rigidly connected to a plurality of cylindrical pile cap structures, and a plurality of box-type steels assembled into the same ring truss shape from the same steel pipe pile pile head consisting of a cylindrical pile cap structure In order to prevent the end of the pile head connection material from coming off at all, a pair of the concave spot welded joints is formed into a box shape having a size larger than that of the box type steel welded joint, and the end is connected to the outer shell side of the end of the pile box connection material. By superimposing, sandwiching and welding only from above, the thickness of the connecting rigid structure, the cross-sectional area, and the second moment of area are greatly increased, and the connecting rigid connection is significantly increased in strength. This allows for multiple cylindrical pile cabs A box truss-type ring truss-type pile head connection structure is constructed and constructed simply and quickly from above only for the plurality of steel pipe pile pile heads made of steel. [2] With this construction method, it is simple and quick. To
On the ground surface of the landslide moving layer, the box-shaped steel ring truss-type pile head connection structure is composed of a plurality of cylindrical pile cap structures, and the same plurality of steel pipe pile pile heads, like a steel caisson foundation head, Structurally, it is constructed and constructed so as to be extremely firmly fixed. [3] Further, a plurality of cylindrical pile cap structures transmit the fixed bending moment very smoothly to the steel pipe pile pile head and the pile body. Therefore, the landslide prevention steel pipe pile with the box-type steel ring truss type pile head connection structure is very useful due to its ring truss type rigid connection and continuous rigid connection ramen effect. [4] The box steel of the ring truss type pile head connection structure of the box steel has very little horizontal deformation, and
Since it has a three-dimensional strength characteristic without warping, the deformation is normal and exhibits an exemplary P-δ curve until yielding, and the stress is transmitted smoothly as usual,
The transmission of stress is very normal and sufficiently smooth. (5) The box steel of the ring truss type pile head connection structure of the box steel is not collapsed by the shear stress from the plurality of steel pipe pile heads, and , Without crushing until yielding to bending stress,
Combining bending stress with axial stress and torsional stress and transmitting,
On the ground surface of the moving layer, the fixed bending moment can be transmitted very normally and sufficiently smoothly even in the case of sliding operation of landslides. The ring truss type pile head connection structure is not only in the initial stage of sliding, but also when sliding occurs and deformation occurs,
The deformation is regarded as a normal and exemplary P-δ curve. [7] The ring truss-type pile head connection structure of the box-shaped steel has a risk of recurrence of a soft hollow part (where multiple slips are present) and the like. When installed on a high landslide transfer ground, the piles in that range cannot be expected to have any ground reaction force, but the ring truss-shaped, bird-shaped, continuous front, rear, left and right four steel pipe pile heads However, even if deformation occurs due to the ring truss type rigid connection and continuous rigid connection rigid frame effect, the deformation of the pile heads of the steel pipe piles is extremely small, but also in the deep underground where the landslide surface exists. In addition, the deformation of the plurality of steel pipe piles is also restrained to be extremely rigid in the direction of the ring truss, and the plurality of steel pipe pile heads and the piles are formed into a tubular shape for landslide sliding operation. The piles are to be resisted together, and the same deformation of the pile is The horizontal reaction force acting on the pile body in the range of the primary sliding surface is greatly reduced by the rear piles in the rows, and the ground sliding force is extremely small. Expect the total ground reaction force of the piles in the range of piles in the range of the piles in the range, and [8] insert and install the plurality of steel pipe piles according to the box truss type ring truss type pile head connection structure. Since the pile arrangement of multiple steel pipe piles is a ring-shaped and dried bird-like arrangement, the horizontal load of the piles varies greatly, but the landslide transfer direction is not constant, and the landslide can be moved in any direction according to the strength of the moving layer. Even if the direction of movement changes arbitrarily, the spacing between the front and rear piles in the shape of a bird in a ring is virtually the same as that in the horizontal, vertical and diagonal directions of the landslide. Is larger than the distance between the front and rear piles, so the horizontal load on the rear pile is greatly reduced. Therefore, the bending moment acting on the piles arranged in a ring like a bird over the whole deep underground is greatly different from the ring like a bird.
The bending moment acting on the rear pile is greatly reduced,

[9]
In the box-type steel ring truss-type pile head connection structure, the plurality of steel pipe pile heads are connected and rigidly connected at the four ends of the box-type steel ring truss-type pile head connection structure. And, the deformation of the plurality of steel pipe piles, due to the ring truss type rigid connection and the continuous rigid connection rigid frame effect, is extremely rigidly constrained in the direction of the ring truss and integrated into a well shape and becomes extremely small, Furthermore, the deformation of the box steel of the ring truss-type pile head connection structure of the box steel is a deformation that exhibits a normal and exemplary P-δ curve, so that the fixed bending moment on the ground surface of the moving bed is greatly reduced. [10] Furthermore, the box truss-type ring truss-type pile head connection structure of the box-type steel has a structure in which the pile arrangement of the plurality of steel pipe piles is a bird-like arrangement in the ring truss direction. , Horizontal load of pile Significantly different in the direction of the ring truss closed in a ring shape, the fixed bending moment of the pile head in the truss unit is continuously shared between the ring truss type continuous four front and left and right steel pipe pile heads. And reduce
In addition, in the entire ring truss closed in a ring shape, the fixed bending moment of the pile head is continuously equalized and reduced in the ring direction, and the fixed bending moment of the pile head is reduced in the horizontal and vertical directions of the landslide. Since the pile arrangement of the plurality of steel pipe piles is arranged in a ring shape and a bird-like arrangement, the bending moment acting on the rear pile is greatly reduced, and the fixed bending moment of the pile head is extremely reduced. [11] Since the ring truss-type pile head connection structure of the box-shaped steel is made of box-shaped steel, it can withstand both axial force, bending moment, and torsional moment. The pile head connecting member of the mold steel is assembled in a ring truss type, and the connection rigid connection structure of the plurality of steel pipe pile heads composed of the cylindrical pile cap structure is a three-dimensional ramen ring truss type seal. The landslide horizontal direction due to the point structure and the plurality of steel pipe pile pile heads being concentrated and rigidly connected at the four ends of the box truss type ring truss type pile head connection structure The four or more steel pipe pile pile heads are connected and rigidly connected to the ring truss type in the horizontal direction with four extremely strong rigidity of the front and back and left and right in a ring truss shape. A plurality of steel pipe pile heads are fixed in a ring truss shape on the ground surface of the moving layer in the form of a ring truss and are extremely firmly fixed. [12] Further, the ring truss type pile head of the box-shaped steel is used. Due to the ring truss type rigid connection and continuous rigid connection rigid frame effect, and the smooth sectional stress transmission effect of the pile cap structure of the invention, the bending moment acting on the pile body deep underground in the vertical direction is extremely large. Equalized to In other words, all of the steel pipe piles are not so-called shear piles, but are not so-called rigid piles such as super shafts, deep foundation piles, well pipe foundations and caisson foundations, but are so-called bending piles. The bending moment acting on the steel pipe pile body is greatly reduced, and the horizontal resistance of the pile is greatly increased.

[13] Further, the plurality of steel pipe piles change from so-called shear piles to bending piles, and the plurality of steel pipe piles change from free pile head to fixed pile head. Changed to one that resists landslides in a well-shaped manner against the sliding motion of the landslide, and has extremely high rigidity, so that the acting sectional force is extremely small and the horizontal resistance of the pile is greatly increased. The cross section of the plurality of steel pipe piles is made thinner and has a relatively small cross-sectional area with a smaller cross-sectional area to make the plurality of steel pipe piles more inexpensive, and the landslide having the box truss type ring truss type pile head connection structure of the present invention of the present invention. Prevention steel pipe pile work is made more economical.

(Claim 4) The cylindrical pile cap structure for connecting a truss-type or ring-truss-type pile head of box-type steel according to the present invention is one of a cylindrical steel having a relatively large cross section and two types for fixing a pile head. Two cut pipes having a diameter of
It consists of three horizontal flat steels. At the factory, one horizontal flat steel with a hole of the same steel pipe pile diameter is factory-welded to the lower open section of one relatively large-section cylindrical steel, and fixed to the inside of the pile head. Two cut pipes having two kinds of diameters for fixing are factory-welded in two steps above and below with one horizontal flat steel sandwiched between them, and a cap hole outer shell structure for inserting a pile head is manufactured and placed. One horizontal flat steel plate without a hole in the upper open section of the cylindrical steel is factory-welded to easily manufacture the cylindrical pile cap structure, which is a closed structure of two cylindrical bodies, at the factory. .

This makes it possible to mass-produce the cylindrical pile cap structure at low cost. Then, at the site, before inserting the steel pipe pile into the pile hole of the landslide ground, By simply inserting the steel pipe pile head into the pile cap structure and simply welding the pile head to the pile head, the cylindrical pile cap structure can be easily constructed and constructed at the pile head.

In terms of construction, one lower cut pipe II inside the cylindrical pile cap structure has an inner diameter equal to that of the steel pipe pile, and the height of the steel pipe pile pile head is raised only by inserting the steel pipe pile pile head. The other upper cut pipe has an outer diameter equal to that of the steel pipe pile, and the steel pipe pile head is pressed down firmly from above just by inserting the steel pipe pile head. Fixed, and one horizontal flat steel inside the cylindrical pile cap structure,
With its horizontal strength, simply insert the steel pipe pile head and weld the steel pipe pile head easily in the field, at the center between two upper and lower cut pipes, Is fixed firmly horizontally, thereby, the cylindrical pile cap structure, even in a cylindrical inner hollow section of a relatively large steel section, from the outer shell side to the steel pipe pile pile head, It can be easily constructed and constructed on site so that cross-sectional forces such as axial force and bending moment can be transmitted smoothly in the horizontal direction.

Furthermore, since the cylindrical shape is convex around the vertical axis, the four ends of the box-shaped steel pile head connecting member assembled in the truss shape have a long circumferential length of the cylindrical shape. It is easily and quickly welded from above only with a sufficient clearance angle without overlapping, and is rigidly connected from above, so that the box-shaped steel torus-type pile head connection structure is very easily and quickly connected to the pile head. In addition, it can be constructed and constructed at low cost.

From a structural point of view, the cross-sectional shape of the cylindrical pile cap structure is a box-shaped closed cross section around the X axis and the Y axis, and a cylindrical closed cross section around the Z axis. The three-dimensional strength characteristics are superior for bending moment, torsional moment and axial force because the cylindrical type has a larger second moment of area than the box type for the same amount of steel. It is very strong and does not cause any bending, torsional or compressive deformation with respect to the bending moment, torsional moment and axial force of the box-shaped steel pile head connecting member assembled in a truss shape. Furthermore, the cylindrical pile cap structure has a cylindrical closed cross section around the Z axis, and a box around the X axis and the Y axis at the four ends of the box-shaped steel pile head connecting member assembled in a truss shape. The stresses (bending stress, torsion stress and axial stress) from the mold closed section are all turned 90 ° from the outer shell side,
Since it is a so-called three-dimensional rament lath with closed point structure and pile cap structure that transmits stress very smoothly to the steel pipe pile pile head whose cross section is a cylindrical closed cross section, bending stress on both sides of the pile head cylinder (Bending tensile stress and bending compressive stress) are very smooth and uniform, and their deformation is also very uniform, and the bending stress is smoothly transmitted to the box-shaped steel truss-type pile head connecting material. , The steel pipe pile head is firmly captured and protected, and even if the sliding progresses and the deformation comes out, the steel pipe pile pile head is completely distorted by the cross-sectional force and deformation of the box-type steel truss-type pile head connecting material. With the effect of reinforcing the pile head, the steel pipe pile can be changed from a so-called shear pile to a bending pile during rigid rigid frame construction, as well as the initial shear force of sliding. , The sliding To the bending moment and deformation when, firmly to allow exert horizontal resistance, furthermore,
The fixed bending moment is smoothly transmitted from multiple steel pipe pile pile heads to the pile body via the box-type steel truss-type pile head connection material, and a large bending moment acting on the steel pipe pile body deep underground is obtained. One relatively large cross-section cylindrical steel, two cut pipes with two different diameters for fixing the pile head, and three horizontal, so as to greatly reduce with its smooth sectional force transmission effect It is a cylindrical pile cap structure for connecting a truss-type or ring-truss-type pile head made of box steel composed of various flat steels.

(Claim 5) A concave in-situ welded fitting having an arc-joined surface according to the present invention is a set of two-pieces having an arc-joined surface.
It is composed of two concave spot welding fittings, and its arc joining surface is a joining surface for connecting and rigidly connecting the outer surface of the cylindrical pile cap structure by field welding only from above with an arbitrary changing joint angle. For the deviation of the intersection angle between the center axes of the two pile cores, the welding angle is changed arbitrarily according to the intersection angle error of the center axis between the pile cores, and the field welding is performed only from above. (Penetration butt welding) to connect and rigidly connect, and when the distance between the pair of two pile cores is displaced, a pair of concave field welding joint fittings having the arc-joined surfaces are vertically opposed. In addition, by sandwiching from above and below and overlapping and welding on site only from above,
In addition, at the time of construction, the pile head connecting material of the same box type steel is lifted by a mobile crane, and the concave field welding having the lower arcuate joining surface of one of the lower side parts already welded on the outside surface of the cylindrical pile cap structure. Place it on top of the fittings,
After that, the other upper part of the concave field welding joint fitting is sandwiched from above and overlapped and welded in place only from above, so that the length of the box-shaped steel pile head connecting material assembled into a truss type is large. In order to adjust the distance between the cores of the piles, the time and labor was spent to eliminate difficult on-site alignment work (on-site cutting work) and on-site welding work from the gap below, This makes it easy and quick to connect the box-type steel pile head connecting members assembled in a truss type to the field easily and quickly. In addition, for the level error between a pair of two pile heads, Is adjusted vertically by the outer surface of the cylindrical pile cap structure to perform on-site welding only from above, and corrects. Connection rigidity With regard to the box-shaped steel which is assembled into the same truss type, the cross-sectional shape is made into a box-shaped closed cross-sectional shape by vertically facing one set of concave field welding joint fittings having the arc-joined surface. By being slightly larger than the box-shaped dimensions of the pile head connecting material, the end of the box-type steel pile head connecting material assembled in the truss shape has a concave in-field welding joint fitting having the circular arc joining surface, By being overlapped doubly, the welding extension of the set of two such concave in-situ welded fittings is lower inner fillet weld to
A completely closed full-length weld extension extending from the side penetration butt weld to the upper outer fillet weld, and from the top only, allows the connection rigidity structure with the cylindrical pile cap structure to be thicker and shorter. The area and the moment of inertia of the cross section are made very large in comparison with each other, and the connection rigidity is greatly increased, whereby a plurality of pile heads of the same steel pipe pile having a cylindrical pile cap structure are provided. Therefore, labor and labor hours of the construction and construction method of the box-type steel truss-type pile head connection structure or the ring truss-type pile head connection structure are reduced.

(Claim 6) A method for constructing a box-type steel truss-type or ring-truss-type pile head connection structure according to the present invention includes the steps of: before inserting a steel pipe pile into a pile hole of a landslide ground at a site;
First, a cylindrical pile cap structure is inserted and welded to the pile head of the steel pipe pile, and then, a box-shaped steel pile head connecting member is inserted into the concave field welding joint to align the pile core with the gap between the pile cores. A method for constructing a landslide prevention steel pipe pile, characterized in that the concave field welding joint is angle-aligned and is welded to the cylindrical pile cap structure from above only all around. Here, since the cylindrical pile cap structure is a cylindrical type having a convex shape around the vertical axis, the four end portions of the box-shaped steel pile head connecting member assembled in the truss type are connected to the circumferential shape of the cylindrical type. Since the length is long, there is a margin without overlapping, the intersection angle is actually larger than 30 °, and furthermore, the box-type steel pile head connecting material assembled in the truss type is made of outer chord material, oblique chord material and As a lower chord material, a set of concave field welding joint fittings with arcuate joint surfaces are used to form a complex truss shape or ring truss shape on the outer surface of the cylindrical pile capping structure, making it easy and quick. Field welding is performed only from above (full circumference welding of fillet welding and penetration butt welding).

In order to prevent the steel pipe pile from having a large gap between the cores of the pile for the landslide prevention pile, the transfer crane was used to attach the steel pipe pile to the upper side of the lower side of the concave field welding joint fitting. A pile of box-shaped steel pile head connecting members assembled in a truss shape is placed on top of each other, and one set of the concave spot welding fittings is sandwiched from above on the outer shell side of the box-shaped steel pile head connecting material to form a box-shaped same shape. By double dominating, the end of the box-shaped steel pile head connecting material assembled in the same truss type can be easily and quickly eliminated without the need for on-site cutting such as on-site cutting. It is a construction method of connecting and rigidly connecting to the cap structure.

Then, the concave field welded joints are formed so that the ends of the plurality of box-shaped steel pile head connecting members assembled in the same truss shape from the steel pipe pile pile head having the cylindrical pile cap structure do not swell at all. Into a box-like shape that is slightly larger
By double-overlapping and pinching the outer shell side of the end of the box-shaped steel pile head connecting material, and by on-site welding only from above,
The thickness, cross-sectional area, and second moment of area of the connection rigid connection structure are extremely large, and the connection rigid connection is significantly increased, thereby forming a plurality of steel pipe pile piles comprising a plurality of cylindrical pile cap structures. A truss-type or ring-truss-type pile of the box-type steel whose shape is formed into a complex truss-type or ring-truss-type by the outer chord, the oblique chord, and the lower chord of the box-type steel pile head connection member at the head This is a construction method to easily and quickly and inexpensively construct the head connection structure. With this method, the truss type pile head connection structure of the box-shaped steel is connected to the plurality of steel pipe piles on the ground surface of the landslide moving layer. The pile head is structurally
This is the method of constructing the box-type steel truss-type or ring-truss-type pile head connection structure that is to be firmly fixed.

The method of constructing the cylindrical pile cap structure according to the present invention is as follows. Before the steel pipe pile is inserted into the pile hole of the landslide ground at the site, the cylindrical pile cap is mounted on the steel pipe pile pile head. By simply inserting the structure and simply welding the neck of the pile head in place, the connection method can be easily and quickly connected to the pile head of the steel pipe pile and rigidly connected. Box-shaped steel truss-type or ring-truss-type pile head connection structure is easily and quickly field-welded from the top only to the outside surface with a set of concave field welding joint fittings having an arc-joint surface, and high-strength connection This is a construction method before the rigid connection, and is a cylindrical type for easily and quickly and inexpensively building and constructing a box-type steel truss type or ring truss type pile head connection structure to the steel pipe pile head. Pile cap It is the elephant of construction methods.

Due to the construction, one lower cut pipe inside the cylindrical pile cap structure has an inner diameter equal to that of the steel pipe pile, and the steel pipe pile pile head is inserted with high precision simply by inserting the steel pipe pile head. The other upper cut pipe has the same outer diameter as the steel pipe pile, and just inserts the same steel pipe pile head to firmly hold the steel pipe pile head firmly from above and fix it vertically. In addition, one horizontal flat steel inside the cylindrical pile cap structure has the horizontal reinforcing performance, and simply inserts the steel pipe pile pile head and welds the steel pipe pile pile head easily by field welding. It is a construction method of a cylindrical pile cap structure to fix the steel pipe pile pile head horizontally and firmly in the center between the two cut pipes of the upper and lower two stages, so that the cylindrical pile cap structure is made of steel Relatively large section Easy and quick construction at the site so that the cross section force such as axial force and bending moment can be smoothly transmitted in the horizontal direction from the outer shell side to the steel pipe pile pile head even in the cylindrical inner hollow section.・ Can be constructed.

Furthermore, since the cylindrical shape is convex around the vertical axis, the four ends of the box-shaped steel pile head connecting member assembled in the truss shape have a long circumferential length of the cylindrical shape. It is a method of constructing a cylindrical pile cap structure that is easily and quickly welded and rigidly connected at the site with a sufficient clearance angle without overlapping, so that the box type steel truss type pile head connection structure is It can be constructed and constructed very simply and quickly on the pile head only from above, and at low cost.

At the time of construction, the box-shaped steel pile head connecting member is lifted by a mobile crane, and a concave site having a lower circular arc-joined surface which has been already site-welded to the outer surface of the cylindrical pile cap structure. A box-shaped steel pile that is assembled into a truss shape by placing it on top of the welded fittings, then sandwiching the other upper concave welded fittings from above and superimposing them and welding them only from above. To adjust the length of the head connection material to the distance between the pile cores, which are also misaligned, it takes time and labor to perform difficult on-site alignment work (on-site cutting work) and on-site welding work from the gap below. In addition to eliminating the need to carry out the work, the on-site connection and stiffening work of a large number of box-shaped steel pile head connection members assembled in the same truss type can be made simple and quick.
For level error between pile heads, concave in-situ welded fittings with a pair of upper and lower arc-joint surfaces are adjusted up and down on the outer surface of the cylindrical pile cap structure and on-site welded only from above, In addition, regarding the rigidity of connection between a pair of two pile heads, the cross-sectional shape of the joint is box-shaped closed by vertically facing one pair of concave field welding fittings having an arc-shaped joint surface. The box shape is a metaphysical shape, and this box shape is slightly larger than the box size of the box steel connection material of the box steel that is assembled in the truss shape. The end of the material is double overlapped with the concave spot welding fitting having the arc joining surface, and the welding extension of the set of two concave spot welding fittings is the lower inner fillet. Weld to side penetration butt fusion Thickness, cross-sectional area, and cross-section of the rigid connection structure that is connected to the cylindrical pile cap structure by being a completely closed full-length weld extension extending only from above through the upper to outer fillet welds It is a method of constructing the cylindrical pile cap structure, which makes the second moment very large by comparison and makes the connection rigidity significantly high, thereby making the box-type steel truss-type pile head connection structure or ring This aims to save labor and shorten working hours in the construction and construction method of the truss-type pile head connection structure.

The permanent landslide prevention steel pipe pile having a box-type steel truss-type pile head connection structure according to the present invention comprises:
Permanent landslide prevention steel pipe pile with a box-type steel truss-type pile head connection structure permanently connected with a box-type steel truss-type pile head connection structure. (Where the next slip is located), etc., it is not possible to expect a ground reaction force on the piles in the range of the primary slip surface when the landslide is moving at high risk of recurrence. Even if deformation occurs due to the truss-type rigid connection and continuous rigid-frame effect of the box-type steel truss-type pile head connection between the steel pipe piles connected in parallel to the truss-type, the piles are laid horizontally and vertically in the landslide. The deformation of the pile is also restrained to the same rigidity, and the deformation of the pile is reduced to the same extent, and the ground reaction force is reduced to the same extent. The horizontal load acting on the piles in the range is greatly reduced by the rear piles,
Expecting ground reaction force on piles in the range of the next sliding surface, and
As a so-called bent pile that allows permanent deformation of the pile body, it reduces bending moment, increases horizontal resistance, and has a soft hollow part with prefectural roads along with piers and roadside works ( In addition to permanently preventing landslides that have a high risk of recurrence (where there are multiple slips), the H-shaped steel, steel pipe piles, reinforced steel pipes, etc. From box-shaped steel, which changes from a rigid section made of poured concrete to an elastic section made of steel pipe piles and reinforcing steel pipes that allow deformation, and makes the section thin and inexpensive with a small section, This is a permanent landslide prevention steel pipe pile with a truss-type pile head connection structure.

The permanent landslide prevention steel pipe piler having a box-type steel ring truss-type pile head connection structure according to the present invention is permanently connected with the box-type steel ring truss-type pile head connection structure. A landslide-preventing steel pipe pile with a box-type steel ring truss-type pile head connection structure. As a result, no ground reaction force can be expected on the piles in the range of the primary sliding surface, and a ring truss type rigid structure with a box-shaped steel ring truss type pile head connection structure Even if deformation occurs due to the stiffening and continuous rigid-connection ramen effects, the deformation of the piles of steel pipe piles is extremely small, and the deformation of the piles is extremely strong in the direction of the ring truss. Multiple steel pipes constrained to the same rigidity The pile head and the pile body are to be integrally resisted to the sliding movement of the landslide in a well shape, and the deformation of the pile body is extremely small like a well shape, and the ground reaction force is extremely small as well. However, the horizontal load acting on the pile in the range of the primary sliding surface is greatly reduced by the plurality of rows of rear piles by the ring-shaped pile-shaped pile, and the secondary sliding surface is provided. The pile body in the range of is expected to have a total ground reaction force with the multiple rows of front piles, and the pile body acts as a so-called bending pile that allows permanent deformation, forming a ring-shaped bending moment Very much reduced,
The horizontal resistance is extremely large in the shape of a cylinder, and together with the pier and roadside works, permanent prevention of landslides with a high risk of recurrence, such as soft hollow areas with prefectural roads (where multiple secondary slips are present), etc. In addition, the cross section of the pile body is changed from a rigid cross section made of conventional H-section steel, steel pipe pile, reinforced steel pipe and poured concrete which does not allow deformation to an elastic cross section made of steel pipe pile and reinforced steel pipe which allows deformation. In other words, it is a permanent landslide prevention steel pipe piler with a box-shaped steel ring truss-type pile head connection structure that makes the cross-section significantly thinner and smaller inexpensive and more economical.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 5 is an embodiment diagram of a permanent landslide prevention steel pipe piler having a box-type steel truss-type pile head connection structure permanently connected with a box-type steel truss-type pile head connection structure. is there.

When the landslide prevention steel pipe pile is installed on a landslide moving ground having a high risk of recurrence, such as a weak hollow portion (where there are multiple slips, 17 and 18), the primary slip surface. No ground reaction force can be expected in the piles 16 in the range 17, and the box-type steel truss-type pile head connection structure 14 is formed between the steel pipe piles 20 that are connected in parallel to the truss type 19 in the landslide laterally arranged in a bird-like configuration. Truss type rigid connection 19 and continuous rigid connection rigid frame 2
Due to the 1 effect, even if the deformation occurs, the deformation of the pile 16 is also restrained to the same rigidity in the horizontal and vertical directions of the landslide, the deformation of the pile 16 is reduced to the same extent, and the ground reaction force is reduced. The horizontal load acting on the pile body 16 in the area of the primary sliding surface 17 is greatly reduced by the rear pile with the pile body 16 of the bird-like arrangement, but the area of the secondary sliding surface 18 is reduced. The pile 16 is a so-called bent pile that expects a ground reaction force and allows the permanent deformation of the pile body 16. Along with the roadside construction 13, the landslide with a high risk of recurrence such as a soft hollow part having a prefectural road 22 (where there are multiple slips 17 and 18) is permanently prevented, and the pile 1
H-section steel 8, steel pipe pile 9, reinforcing steel pipe 10, and cast concrete 1
1 to a resilient cross section 20 consisting of a steel pipe pile 9 and a reinforcing steel pipe 10 allowing deformation,
The cross section is made economical by making it thin and inexpensive with a small cross section.

FIG. 6 shows the implementation of a permanent landslide prevention steel pipe piler having a box-type steel ring truss-type pile head connection structure permanently connected with a box-type steel ring truss-type pile head connection structure. FIG.

In this embodiment, the landslide prevention steel pipe piler has a soft hollow portion (where there is a multiple slip).
7, 18), etc., the ground reaction force cannot be expected on the piles in the range of the primary sliding surface 17 when the landslide moving ground having a high risk of recurrence is present, and the ring-shaped steel pipe piles 20 are arranged in a bird-like shape. Even if deformation occurs due to the ring truss type rigid connection 19 and the continuous rigid connection rigid frame 21 effect of the box truss ring truss type pile head connection structure 14, the deformation of the plurality of steel pipe pile heads does not occur. The fact that it is very small originally restricts the deformation of the plurality of piles 16 equally to the ring truss in the direction of the ring truss so that the plurality of steel pipe pile heads and the piles 16 are prevented from sliding movement of the landslide. And resist together.
Although the deformation of the pile 16 is made extremely small like a well cylinder and the ground reaction force is made extremely small as well, the primary slip surface 1 is formed by the pile 16 having a ring-shaped dried bird-like arrangement.
7, the horizontal load acting on the piles 16 in the range of 7 is significantly reduced by the rear piles in the plurality of rows, and the pile 16 in the range of the secondary sliding surface 18 is combined with the front piles in the rows to reduce the total ground resistance. As a so-called bent pile that expects a force and allows the pile body 16 to be permanently deformed, the acting bending moment is extremely greatly reduced in a ring shape, and the horizontal resistance is extremely large in a well shape. , Along with the dike 12 and the roadside construction 13, permanently prevent landslides with a high risk of recurrence such as soft hollow parts (places 17 and 18 with multiple slips) having prefectural roads 22 and the piles The cross section of the body 16 is a rigid cross section 20 made of H-shaped steel, steel pipe pile 9, reinforcing steel pipe 10, and poured concrete 11 which does not allow deformation, and an elastic cross section 20 made of steel pipe pile 9 and reinforcing steel pipe 10 which allows deformation.
To make the cross section much thinner and inexpensive with a small cross section, making it more economical.

FIG. 7 is a graph showing a change in the load point interval between the corners of the rigid frame structure of the box-shaped steel and the axial load.

In the graph of the change of the load point interval δ shown with respect to the axial load P according to this embodiment, the corner of the rigid frame structure of the box-shaped steel is twisted with respect to the axial load P. It has a moment T, but has little horizontal deformation, and
It has a three-dimensional strength characteristic without warping, deforms normally until yielding, and exhibits a typical P-δ curve. In the early stage of change δ, the load of elasticity theory (torsional load is ignored) It exhibits the same rise as the change line A of the point interval, and the maximum axial load is the maximum axial load of the pipe (P = 52.8).
t) Compared to the change curve B of the load point interval of the combination of the axial force and the bending moment which is the same as Pp, the maximum axial load is reduced without warpage due to the torsional moment T, Even if δ occurs, the deformation is normal and exemplary, so that bending stress is normally synthesized and transmitted until axial rupture is caused by the axial load P, and the bending moment is normally transmitted. The load point of the combination of the axial force, bending moment, and torsional moment that makes the deformation a normal and exemplary P-δ curve not only in the initial stage without any change δ but also in the yield period and rupture period, as well as in the initial stage without any change δ The interval change curve C is used.

FIG. 8 is a plan view in which a box-type steel truss-type pile head connection structure permanently connects a plurality of landslide prevention steel pipe piles to the pile head connection rigidly, and FIG. 9 is a vertical sectional view.

In this example, the box-type steel truss-type pile head connection structure includes a plurality of cylindrical pile cap structures 23, a concave field welded joint 24 having a plurality of arc-joined surfaces, and a plurality of truss-type box-type steel piles. The head connecting member 25 is used.

Then, the ends of the truss-type box head steel connection members 25 having a plurality of truss-type box-shaped steels are connected to the plurality of cylindrical pile-cap structures 23 by the truss-type Field welding according to the central axis 28 of the truss type, and the truss type is connected and rigidly connected to the truss type with high strength, and the plurality of steel pipe pile pile heads 26 are firmly fixed to the ground surface of the transfer layer. The ends of the plurality of box-shaped steel pile head connecting members 25 are prevented from swelling even if landslide transfer progresses and deformation occurs, and the deformation of the corners of the rigid rigid frame structure. And a plurality of steel pipe pile pile heads 26 in which the fixed bending moments are successively arranged in parallel in a plane in a bird-like manner through a plurality of truss-type box pile steel connection members 25 Very smooth transmission between multiple cylindrical pile caps. The pile head 26 of the structure 23 is pile-capped from the upper side of the outer shell according to the pile core axis 29, and is strongly reinforced and protected by on-site welding 37 before being inserted into the pile hole. With the cut pipes 27, 31 and the three horizontal plate steels 30, 32, 33, the pile head 26 is fixed to the pile head 26 with high precision and high strength in two directions of horizontal and vertical directions.

Cylindrical type that changes the cross-sectional stress of the fixed bending moment through a box-type steel truss-type pile head connection structure by 90 ° from the outer shell side and transmits it very smoothly in two directions, horizontal and vertical. Due to the three-dimensional high strength characteristics of the closed cross-section structure,
The truss-type rigid connection and the continuous rigid-connection rigid frame effect of the box-type steel truss-type pile head connection structure are extremely smooth between a plurality of steel pipe pile pile heads 26 arranged in parallel in a horizontal plane. It is transmitted and exerted, and is transmitted very smoothly from the plurality of steel pipe pile pile heads 26 to the piles underground deeply in the vertical direction, and exhibits excellent three-dimensional strength characteristics and three-dimensional sectional stress transmission. Due to the characteristic, the deformation of the pile head of the plurality of landslide prevention steel pipe piles 26 is small, the deformation of the pile body is also reduced, the ground reaction force is reduced accordingly, and the bird-like arrangement is adopted. Primary sliding surface 17 with pile 26
The horizontal load acting on the pile body 26 in the range of 2 is greatly reduced by the rear pile 26, and the ground reaction force is not expected.
In the front pile 26 in the range of 8, a ground reaction force is expected, and the pile body 26 is a so-called bending pile which allows permanent deformation. The horizontal resistance of the piler is increased, and the cross section of the steel pipe pile 26 is made thin and economical with a small cross section.

FIG. 10 is a plan view in which a concave field welded joint having a cylindrical pile cab structure and an arc-jointed surface permanently connects one landslide-preventing steel pipe pile head to a trough-shaped pile head connection. FIG. 11 is a side view thereof, and FIG.
Is a vertical sectional view.

In this embodiment, the cylindrical pile cap structure is composed of one cylindrical steel 23 having a relatively large cross section and two cut pipes 27, 3 having two kinds of diameters for fixing a pile head.
One and three horizontal flat steels 30, 32, 33.

One of the lower cut pipes 27 of the cut pipes 27, 31 has an inner diameter equal to that of the steel pipe pile 26, and the pile pipe head 26 is raised only by pile-capping the steel pipe pile head 26. The other upper cut pipe 31 has an outer diameter equal to that of the steel pipe pile 26 and is pile-capped to the same steel pipe pile pile head 26 so that the steel pipe pile pile head 26 can be attached from above. Hold down firmly and fix vertically.

Then, the inner and outer three horizontal plate steels 30,
32, 33, with its horizontal strength, insert the steel pipe pile pile head 26 and easily weld the fillet weld of the steel pipe pile pile head 3
7 and 2 cut pipes 27, 31
The steel pipe pile pile head 26 is horizontally and firmly fixed at the center between the two.

As a result, the cylindrical pile cap structure allows the axial force or bending in the horizontal direction from the outer shell side to the steel pipe pile pile head 26 even in the cylindrical inner hollow section having a relatively large steel section. This makes it possible to smoothly transmit cross-sectional forces such as moments, and also allows easy construction and construction at the site.

The concave-shaped field welding joint fitting having an arc-joined surface is a box-type steel pile head connecting member assembled in a truss shape because the cylindrical pile cap structure 23 is a cylindrical shape convex around the vertical axis. The four end portions of the truss are provided with a set of concave field welded joint fittings 24 having an arc-joined surface with a sufficient clearance angle without overlapping because of the long circumferential length of the cylindrical shape. The ends of the plurality of box-shaped steel pile head connecting members 25 assembled into a mold are formed into a plurality of cylindrical pile cap structures 2.
In accordance with the angle of intersection with No.3, field welding (full circumference welding 34, 35, 36 and fillet welding 58, 59) is performed simply and quickly only from above according to the central axis 28 from above.
Even if the gap between the pile cores 29 is not adjusted at the site, the truss type can be connected and rigidly connected to the truss type with high strength.

A plurality of box-shaped steel pile head connecting members 25 assembled in the same truss shape from the steel pipe pile pile head 26 having the cylindrical pile cap structure 23 so that the ends of the concave field welding joints are not bent at all. 24 is formed into a box-like shape having a size slightly larger than that of the box-type steel pile head connection member 25, and is overlapped and sandwiched doubly on the outer shell side of the pile head connection member 25, and field welding is performed only from above (through butt welding 34, 35, 36 and fillet welds 58, 5
9) and the welding extension of the set of two of the concave type field welding fittings 24 is formed by the lower inner fillet weld 5.
9 to the side penetration butt weld 34 to the upper outer fillet weld 58, and a completely closed full circumference weld extension only from above, thereby increasing the thickness, cross-sectional area, And (2) The secondary moment of the cross section is made very large, and the connection is rigidly connected with a significantly high strength, and the plurality of steel pipe pile pile heads 26 composed of the plurality of cylindrical pile cap structures 23 are
The box-shaped steel truss-type pile head connection structure 25 is simply and quickly constructed and constructed only from above.

In terms of structure, the above-mentioned cylindrical pile cap structure 2
3 is a box-shaped closed cross section around the X axis and the Y axis;
In addition, it has a cylindrical closed section around the Z axis, and the second moment of area is larger in both the box type and the cylindrical type, and the cylindrical type has a larger second moment of area than the box type with the same amount of steel. It has excellent three-dimensional strength characteristics with respect to bending moment, torsional moment and axial force, and is very strong, and also with respect to bending moment, torsional moment and axial force at the corners of the rigid frame structure. No bending, twisting or compressive deformation occurs at all. Further, with its cylindrical closed cross section around the Z axis, the X-shape of the four ends of the box-type steel truss-type pile head connection structure 25 is obtained. The stress (bending stress, torsion stress, and axial stress) from the box-shaped closed section around the axis and the Y-axis is all turned 90 ° from the outer shell side, and the steel pipe pile pile head whose section is a cylindrical closed section Very smooth stress to 26 Because of the so-called three-dimensional rament lath closed point structure and pile cap structure for transmitting, the bending stress (bending tensile stress and bending compression stress) on both sides of the pile head 26 is very smooth and uniform, and ,
The deformation is very even.

In this way, the bending stress is smoothly transmitted to the steel pipe pile 26 in the deep underground, and the steel pipe pile pile head 26 is reinforced and protected firmly. Due to the high-precision and high-strength pile head reinforcement / pile head connection rigidity effect, even if the steel pipe pile 26 is changed from a so-called shear pile to a bending pile in a rigid rigid frame structure, only the initial shear force of sliding starts. In addition, the bending moment and deformation at the time when the sliding is advanced, the deformation is normal and clean, so that the horizontal resistance can be firmly exerted. The fixed bending moment is smoothly transmitted in the horizontal direction between the plurality of steel pipe pile pile heads 26 that are arranged in a bird's-eye shape continuously in a plane, and the plurality of steel pipe pile pile heads 26 are simultaneously transmitted from the plurality of steel pipe pile pile heads 26. To the pile Teimage moment smoothly by transmitting the vertical direction, a large bending moment acts in the same steel pipe pile body of groundwater deep, by its smooth three-dimensional cross-sectional stress transmission effect is to greatly reduce.

FIG. 13 is a plan view in which a box-type steel ring truss-type pile head connection structure permanently connects a plurality of landslide prevention steel pipe piles to the pile head connection rigidly, and FIG. 14 is a vertical sectional view. . In this example, the box truss type ring truss type pile head connection structure is composed of a plurality of cylindrical pile cap structures 23, a concave field welded joint 24 having a plurality of arc joining surfaces, and a polygon having a regular pentagon or more, and It is composed of a plurality of ring truss-type box-shaped steel pile head connecting members 25 in which the angle between the outer chord material and the oblique chord material is 1/3 of the inner angle.

Then, with the concave in-situ welded joint structure 24 having a plurality of arc joining surfaces, the end angles of the plurality of box-shaped steel pile head connecting members 25 are actually set to be larger than 30 °,
Its shape is a polygonal pentagon or more, and it is formed and arranged in a ring truss shape in which the angle between the outer chord material and the oblique chord material is 1/3 of the inner angle.

In this way, the plurality of cylindrical pile cap structures 23 are welded on site (through butt welding 35, 36 and fillet welding 37) according to the center axis 28 of the ring truss type, and are connected to the ring truss type with high strength. It is rigidly connected and solidly resists against landslide operation in a wellbore shape. A plurality of steel pipe pile pile heads 26 in a plurality of rows are firmly fixed in a wellbore shape on the ground surface of the transfer layer. Further, the ends of the plurality of box-shaped steel pile head connecting members 25 of the ring truss type are designed so that even if the landslide movement progresses and deformation occurs, no swelling occurs, and a plurality of rows are provided. Of the plurality of steel pipe pile pile heads 26 is extremely small in the same tubular shape, and the deformation of the corner portion of the rigid frame structure is normal and clean. Pile head connection 2
5, a plurality of rows of steel pipe pile pile heads 2 in which a fixed bending moment is continuously arranged in a ring shape in a plane in a bird's-eye manner
6 and the pile head 26 of the plurality of cylindrical pile cab structures 23 is moved from the outer shell upper side to the pile core shaft 2.
9 before the pile cap is inserted into the pile hole, it is strongly welded and protected by in-situ welding 37, and the cut pipes 27 and 31 of the upper and lower inner two stages and the three flat plate steels 30, The pile head 26 is fixed to the pile head 26 with high precision and high strength in two directions, that is, horizontal and vertical directions.

Then, the sectional stress of the fixed bending moment through the box truss type ring truss-type pile head connection structure is changed by 90 ° from the outer shell side from one side in the horizontal direction to two directions of horizontal and vertical directions. Due to the three-dimensional high strength characteristics of the cylindrical closed cross-section structure that transmits very smoothly, the ring truss type rigid connection and continuous rigid connection rigid frame effect of the box truss type ring truss type pile head connection structure can be achieved in a horizontal plane. It is transmitted very smoothly between a plurality of rows of steel pipe pile heads 26 in a plurality of rows arranged in a staggered manner in a continuous manner, and is underground from a plurality of rows of a plurality of steel pipe pile piles 26 in a vertical direction. It is transmitted very smoothly to a deep pile body and is exerted. Due to its excellent three-dimensional strength characteristics and three-dimensional cross-sectional stress transmission characteristics, the deformation of the pile head of the plurality of rows of the plurality of landslide prevention steel pipe piles 26 is small. The thing is that the pile Deformed less of, and smaller ground reaction force in response thereto, and with at pile body 26 of the ring-shaped interference bird-like arrangement, the primary sliding surface pile body 2 range of 17
6 is extremely reduced by the plurality of rows of rear piles 26 and the ground reaction force is not expected, and the piles 26 in the range of the secondary sliding surface 18 are provided by the plurality of rows of front piles. 2
6, the pile body 26 is a so-called bending pile that allows permanent deformation, and the acting bending moment is extremely reduced in a ring shape. The horizontal resistance of the steel pipe pile 26 is made extremely large in the shape of a well and the cross section of the steel pipe pile 26 is made much thinner and more economical with a small cross section.

FIG. 15 shows a plane in which a concave in-situ welded joint having a cylindrical pile cap structure and an arc-joined surface permanently connects one landslide prevention steel pipe pile pile head to a ring truss type pile head connection. FIG. 16 is a side view, and FIG. 17 is a vertical sectional view.

In this example, the cylindrical pile cap structure is composed of one cylindrical steel 23 having a relatively large cross section of 6 and two cut pipes 27, 3 having two kinds of diameters for fixing a pile head.
1 and three horizontal flat steel plates 30, 32, 33.

Then, of the cut pipes 27 and 31,
One lower-stage cut pipe 27 has an inner diameter equal to that of the steel pipe pile 26, and tightly joins the steel pipe pile pile head 26 with high precision only by pile-capping the steel pipe pile head 26,
Further, the other upper cut pipe 31 has an outer diameter equal to that of the steel pipe pile 26 and is vertically fixed by firmly pressing the steel pipe pile pile head 26 from above only by pile capping the steel pipe pile pile head 26. doing.

Further, the inner and outer three horizontal flat steel plates 3
0, 32, and 33 have two horizontal cut-off pipes 27 by inserting the steel pipe pile pile head 26 and simply welding the fillet weld 37 to the steel pipe pile pile head. ,
At the center between 31, the steel pipe pile pile head 26 is fixed firmly horizontally, whereby the cylindrical pile cap structure has a relatively large cylindrical inner hollow section made of steel. Cross-sectional forces such as axial force and bending moment can be smoothly transmitted from the outer shell side from one side in the horizontal direction to the steel pipe pile pile head 26, and can be easily constructed on site.・ Can be constructed.

The concave-shaped field welding joint fitting having an arc-joined surface is a box-shaped steel pile head assembled in the same ring truss shape because the cylindrical pile cap structure 23 is a cylindrical shape convex around the vertical axis. The four end portions of the connecting member 25 are formed into a ring truss type with one set of the concave spot welding fittings 24 having a sufficient clearance angle without overlapping because of the long circumferential length of the cylindrical shape. The ends of the plurality of box-shaped steel pile head connecting members 25 to be assembled have an intersection angle of actually larger than 30 °, a polygonal shape of a regular pentagon or more, and the outer chord material and the oblique chord material. It is formed and arranged in a ring truss shape whose angle is one-third of its internal angle, and is easily and quickly welded from above only in accordance with the central axis 28 in accordance with the intersection angle with the cylindrical pile cap structure 23 from above. (All-around welding of penetration butt welding 34, 5,36 and fillet welding 58,5
9) It is possible to easily connect and rigidly connect the pile truss type to the ring truss type easily without any alignment between the pile cores 29 at the site.
The pair of box-shaped steel pile head connecting members 25 assembled in the same ring truss shape from the steel pipe pile pile head 26 made of In the same large box shape, it is double overlapped and pinched on the outer shell side of the end of the pile head connecting material 25 of the same box type steel and field welded only from above (through butt welding 34, 35, 36 and fillet welding) 58, 59)), and the welding extension of the set of two of the concave in-field welded joint fittings 24 is from the lower inner fillet weld 59 to the side penetration butt weld 3
The thickness, cross-sectional area, and second-order moment of area of the connection rigid connection structure are extremely reduced by being a completely closed, all-around weld extension extending only from above through the upper to outer fillet welds 58. A box-shaped ring truss-type pile head connection of a plurality of steel pipe pile pile heads 26 of the same plurality of rows comprising a plurality of cylindrical pile cap structures 23 The structure 25 is constructed and constructed simply and quickly only from above.

Due to the structure, the cross-sectional shape of the cylindrical pile cap structure 23 is a box-shaped closed cross section around the X-axis and the Y-axis, and a cylindrical closed cross-section around the Z-axis. In addition, the cylindrical type has a larger second moment of area than the box type for the same amount of steel, so it has excellent three-dimensional strength characteristics with respect to bending moment, torsional moment and axial force. It is very strong and does not cause any bending deformation, torsional deformation and compressive deformation against the bending moment, torsional moment and axial force of the corner of the rigid frame structure. With the cylindrical closed cross section around the axis, the X of the four ends of the ring truss type pile head connection structure 25 of box type steel
From the box-shaped closed section around the Y axis and the Y axis (bending stress,
Torsional stress and axial stress) are all turned by 90 ° from the outer shell side from one side in the horizontal direction, and the stress is transmitted very smoothly to the steel pipe pile pile head 26 having a cylindrical closed section. It is a closed point structure and a pile cap structure of a so-called three-dimensional ramen ring truss.

Thus, the bending stress (bending tensile stress and bending compression stress) on both sides of the cylinder of the pile head 26 is very smooth and uniform, and the deformation is also very uniform. In addition to smoothly transmitting the bending stress to the pile 26, the steel pipe pile head 26 is reinforced and protected firmly, and even if deformation occurs due to sliding out, the high precision and high strength pile head reinforcement Even if the steel pipe pile 26 is changed from a so-called shear pile to a bending pile in a rigid rigid frame structure due to the pile head connection rigidity effect, not only the initial shear force of the slide, but also the progress of the slide For bending moment and deformation, make the deformation normal and clean, so that it can firmly exert horizontal resistance,
A fixed bending moment is applied between the plurality of steel pipe pile heads 26 in a plurality of rows arranged in a staggered manner in a ring shape in a horizontal direction through a box-shaped steel ring truss type pile head connection structure 25 in a horizontal direction. Large bending acting on the same steel pipe pile body in the deep underground by transmitting the fixed bending moment smoothly to the vertical direction from the plurality of steel pipe pile pile heads 26 in a plurality of rows to the pile body. The moment is greatly reduced due to its smooth three-dimensional sectional stress transmission characteristics.

FIG. 18 shows that the landslide prevention pile has a free pile head.
It is a bending moment figure shown when it is a main pile.

In this bending moment diagram, when the landslide prevention pile is a single pile with a free pile head 53, the pile head 43 of the landslide prevention pile on the ground surface 38 is free to pile head, and the pile body of the landslide surface 39 is The pile body 44 is a single pile, and the pile tip 45 of the immovable layer deep underground is the tip of an infinite pile. The horizontal load acting on the single pile pile 44 on the landslide surface is very large. The force is 55, so that the pile 4
0 is very large, and the ground reaction force is a very large ground reaction force RA. However, the distribution of the bending moment MA acting on the pile body 40 is zero at the pile head 43 and the landslide surface 39 is a positive maximum (maximum) slightly above the pile 44, passed through the landslide surface 39, is slightly zero below, and the sign of the sign is reversed, and the pile 44 of the landslide surface 39 is reversed. Is somewhat negative below (minimum), and again zero at the pile tip 45 of the immobile layer.
The bending moment MA acting on zero is very large.

As a result, basically, the cross section of the pile body 40 must be a thick-walled, large cross-sectional area and extremely rigid rigid body, and the pile body 40 cannot be deformed. The pile body 40 is very expensive as a so-called shear pile, and is very uneconomical.
Furthermore, in a special case where the pile 40 is installed in the range where the multi-level sliding surface exists, the soil mass on the valley side of the landslide moving layer is deformed first, and the ground reaction force can hardly be expected. Therefore, the cross section of the pile body 40 is not allowed to be deformed at all, and it must be a rigid cross section having an increasingly larger cross-sectional area, and even if a tension tie rod is attached, no deformation is generated at all. Is impossible, the landslide prevention pile is only a temporary emergency, and it becomes very expensive, and it is almost impossible to install a single pile with free pile head. It becomes something.

FIG. 19 is a bending moment diagram in the case where the landslide prevention pile is a rigidly rigid frame type two pile fixed to the pile head.

In this bending moment diagram, when the landslide prevention pile is a two-pile fixed to the rigid head of the rigid frame structure type 54, the pile heads 47, 5 of the landslide prevention pile on the ground surface 38 are shown.
Numeral 0 denotes a rigid-headed rigid-frame-structure-type pile head fixed, a horizontal beam 46 on the ground surface 38 is a rigid-connected rigid-frame-structure-type horizontal beam 46, and a landslide surface 39 with a pile-rigged rigid-frame-type two-pile. The pile tips 49, 52 of the immovable layer in the deep underground are the ends of infinite piles, and the horizontal load acting on the piles 48, 51 of the two piles on the landslide surface is very low. The horizontal burden 56 becomes very large and the horizontal burden 57 becomes very small.

As a result, the deformation of the piles 41, 42 occurs equally small, and the ground reaction force becomes the same small ground reaction force RB, RC.
The distribution of the bending moments MB, MC and MD acting on the landslide surface 39 is the largest negative at the pile heads 47 and 50.
Are slightly above the piles 41, 42 of the landslide surface 39, and have passed the landslide surface 39, and are slightly below zero. Is somewhat negative below, is again zero at the pile tips 49,52 of the immobile layer, is negative maximum at the front end 47 of the cross beam 46, and is positive at the rear end 50 of the cross beam 46. The bending moments MB, MC and MD acting on the piles 41 and 42 and the cross beam 46 are the largest, and the bending moments MB, MC and MD are smaller in the former two and larger in the last one.

Thus, basically, the pile members 41, 42
Can be made thin and elastic with a small cross-sectional area and small rigidity. The piles 41 and 42 can be deformed, and the piles 41 and 42 are inexpensive as so-called bent piles. It is very economical. Furthermore, in a special case where the piles 41 and 42 of the rigid rigid frame structure type are installed in the range where the multi-order sliding surface exists,
Even if the soil mass on the valley side of the landslide transfer layer is deformed first, the ground reaction force RB can be expected on the mountain side of the pile body 42, and the magnitude of the ground reaction force RB is reduced, and Since the ground reaction force RC of 41 is hardly required, it can be applied as a landslide prevention pile in a range where a multi-level sliding surface exists, and the cross sections of the pile bodies 41 and 42 are deformable, and have a small cross-section elasticity. Since it is possible to make elasto-plastic design easy so that it is safe even if deformation occurs, there is no need to attach a tension tie rod, and the landslide prevention pile will be permanent for a long time It is very inexpensive, and it is very useful to install a rigid pile rigid structure type pile head fixed two piles.

[0093]

According to the present invention, a fixed bending moment is smoothly transmitted from a plurality of steel pipe pile pile heads to the pile main body through a plurality of box-shaped steel pile head connecting members assembled in a truss type, and the truss type rigid connection is performed. And the bending moment acting on the steel pipe pile body in the deep underground is greatly reduced by the rigid frame effect.

Further, the cross section of the plurality of steel pipe piles is made thin and has a relatively small cross-sectional area to make the plurality of steel pipe piles inexpensive. Is economical.

Furthermore, the horizontal load acting on the pile body in the range of the primary slip surface such as a place where there is a soft hollow part (where a multi-order slip exists) is greatly reduced by the rear pile, and In anticipation of the total ground reaction force of the pile in the range of the slip surface,
In addition, the pile body is a so-called bent pile that allows permanent deformation, the bending moment is reduced, the horizontal resistance is increased, and there is a soft hollow part (where multiple slippage is present)
Permanently prevent landslides with high risk of recurrence.

[Brief description of the drawings]

FIG. 1 is a general view of a truss type conventional pile head connection structure of a landslide prevention steel pipe piler.

FIG. 2 is a plan view of FIG. 1;

FIG. 3 is a vertical sectional view of FIG. 1;

FIG. 4 is an embodiment view of a landslide prevention steel pipe piler having the pile head connection structure of FIG. 1;

FIG. 5 is an explanatory diagram showing an example of an embodiment of a landslide prevention steel pipe piler having a truss-type pile head connection structure of the present invention.

FIG. 6 is an explanatory view showing an example of an embodiment of a landslide prevention steel pipe pile having a ring truss type pile head connection structure of the present invention.

FIG. 7 is an explanatory diagram of a change in a load point interval at a corner portion of a rigid frame structure formed by a box-shaped steel pile head connecting member with respect to an axial load in one embodiment of the present invention.

FIG. 8 is a plan view showing a state in which the box-type steel truss-type pile head connection structure according to one embodiment of the present invention rigidly connects a plurality of landslide prevention steel pipe piles.

9 is a vertical sectional view of FIG.

FIG. 10 is a plan view showing a state in which a pile head of one landslide prevention steel pipe pile is connected to a truss type pile head in one embodiment of the present invention.

FIG. 11 is a side view of FIG. 10;

FIG. 12 is a vertical sectional view of FIG. 10;

FIG. 13 is a plan view showing a state in which a pile head connection structure rigidly connects a plurality of landslide prevention steel pipe piles to a ring truss type in one embodiment of the present invention.

14 is a vertical sectional view of FIG.

FIG. 15 is a plan view showing a state in which a pile head of one landslide prevention steel pipe pile is connected to a ring truss type in one embodiment of the present invention.

FIG. 16 is a side view of FIG.

17 is a vertical sectional view of FIG.

FIG. 18 is a bending moment diagram when the landslide prevention pile is a single pile with a free pile head.

FIG. 19 is a bending moment diagram in a case where the landslide prevention pile is a rigid pile rigid structure type pile head fixed to two piles.

[Explanation of symbols]

Reference numeral 23: cylindrical pile cap structure, 24: concave in-site welded joint, 25: pile head connecting material, 26: steel pipe pile, 27: lower cut pipe, 30: horizontal intermediate flat steel plate, 31: upper cut pipe, 32 ... lower horizontal flat steel plate, 33 ... upper horizontal flat steel plate.

Claims (6)

[Claims] 1. A plurality of steel pipe piles, a plurality of cylindrical pile cap structures connected to the pile tops of the steel pipe piles, and a plurality of concave sites welded and connected at an angle to the sides of the pile cap structures. A landslide having a truss-type pile head connection structure comprising: a welded joint; and a plurality of box-shaped steel pile head connection members that are aligned with the gap between the pile cores between these field welded joints and incorporated into a truss type. Prevent steel pipe piles. 2. A plurality of steel pipe piles arranged in a plurality of rows, a plurality of cylindrical pile cap structures connected to the pile tops of the steel pipe piles, and welded and connected at an angle to the side surfaces of the pile cap structures. A ring truss-type pile comprising: a plurality of concave type field welded joints; and a plurality of box-shaped steel pile head connecting members which are aligned with the gap between the pile cores between these field welded joints and incorporated into the ring truss type. Landslide prevention steel pipe pile with head connection structure. 3. The plurality of box-shaped steel pile head connecting members form a polygon having a regular pentagon or more, and the angle between the outer chord member and the oblique chord member is one-third of the inner angle. Item 3. A landslide prevention steel pipe pile having the ring truss type pile head connection structure according to Item 2. 4. The cylindrical pile cap structure has a cylindrical main body having a relatively large cross section, an upper small diameter having two kinds of diameters for fixing the pile head, that is, a cut pipe having the same diameter as the pile head, and a lower pipe large. A cut pipe having a diameter, i.e., a bore into which the pile head is inserted, and a pipe 3 welded to the cylindrical body.
4. A flat steel plate comprising: two horizontal flat steel plates, namely, an upper blocking flat steel plate, an intermediate flat steel plate interposed between the cut pipes, and a lower flat steel plate having an insertion hole for the pile head. Landslide prevention steel pipe pile described in Crab. 5. The concave-shaped field welded joint is vertically divided into two parts so that an end of the pile head connecting member is inserted and aligned with a gap between pile cores. The landslide prevention steel pipe pile according to claim 4, wherein after being angle-adjusted to the mold pile cap structure, the entire circumference is finally welded only from above to be integrally welded. 6. At the site, before inserting a steel pipe pile into a pile hole of a landslide ground, first, a cylindrical pile cap structure is inserted into a pile head of the steel pipe pile and welded. Inserted into the concave field welded joint and aligned with the gap between the pile cores, this concave field welded joint is angle-aligned and welded to the cylindrical pile cap structure from the entire circumference only from above to be integrated. Construction method of landslide prevention steel pipe pile characterized by welding.