JPH0639775B2 - Inclined drainage reinforcement pile in sandy ground - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention prevents the sandy ground from particularly tensile failure, has a drainage function, and resists vibration in any direction of the ground. A sloped drainage reinforcement pile having strength.

2. Description of the Related Art Conventional methods for improving sandy ground include a sand compaction method, a gravel compaction method, a vibro flotation method, a deep layer mixing method, and a sheet pile method.

Problems to be Solved by the Invention However, the gravel compaction construction method is expected only for the drainage effect, and the sand compaction construction method and the vibro flotation construction method have only the effect of simply compacting the sandy ground, and the vertical direction. I was only able to set up.

Furthermore, the deep-mixing method is only a method of hardening the ground with an improver such as cement.If it is used on sandy ground, defective work occurs and the load concentrates on the defective work part during an earthquake. There is a risk of destruction, and the sheet pile method was only a method of temporarily tightening. Moreover,
With the exception of the sheet pile method, only the newly constructed ground can be improved, and when the sandy ground is liquefied by the earthquake and tensile force acts on the ground and the ground is destroyed, the gravel pile or sand pile resists the above tensile force. There was a problem that there was no power to do it.

The present invention was made in order to solve the problems of the above conventional construction method, and the purpose thereof is to effectively prevent tensile failure of the ground caused by liquefaction of the sandy ground during an earthquake, Providing sloping drainage reinforcement piles that can not only prevent residual settlement after an earthquake but also effectively cope with existing structures such as tanks, river dikes, embankments, buried objects, semi-underground structures Especially.

[Structure of the Invention] Means for Solving Problems The inclined drainage reinforcement pile in the sandy ground of the present invention has an uneven surface in a long hole diagonally drilled in the sandy ground. Arrange a deformed PC rod, or a basket rebar composed of a plurality of hoop muscles and a main bar that connects these hoop muscles, fill the gaps between these deformed PC rods or basket rebars and the long holes with crushed stone, and sand It is characterized in that it is configured to resist the tensile force and compressive force of the ground, and is characterized in that the upper end portion of the pile is fixed to the surface ground by means of ground fixing means such as concrete cement.

Embodiment Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 is a sandy ground in which a buried object 2 such as a box-type buried pipe and a semi-underground structure 3 such as an excavated road are constructed.

In the liquefaction risk area A of the ground around these buried objects 2 and semi-underground structures 3, the small-diameter drainage reinforcement pile 4 of the present invention is driven in the inclined direction or the vertical direction with respect to the ground surface. .

The upper end of the drainage reinforcement pile 4 is exposed on the ground surface,
It is connected to the catchment mass 5. Therefore, the drainage reinforcement pile 4
The interstitial water that has been absorbed by and risen by the
It is collected in and drained. The upper end portion of the drainage reinforcement pile 4 is fixed to the surface ground by means of ground fixing means such as concrete cement.

The structure of the drainage reinforcement pile 4 is, for example, as shown in FIG. 2, a deformed PC rod 4 in which a long hole drilled in the ground 1 has an inner diameter of 100 mm and a node diameter of about 150 mm is formed in an uneven surface.
A is arranged and crushed stones 4b having a size of about 25 mm or less are densely packed around the structure a to have a pile diameter of about 250 mm.

Therefore, the crushed stone 4b meshes with the surrounding sandy ground 1 and also with the deformed PC rod 4a.
When a tensile force acts on the deformed PC rod 4a via the crushed stone 4b, the deformed PC rod 4a is transferred to the ground 1
Resist the tensile force of.

Further, even if a compressive force acts on the ground 1, the deformed PC rod 4a similarly receives a resistance force by the crushed stone 4b.

Further, since there are voids between the crushed stones 4b, the pore water in the surrounding ground 1 is absorbed and rises therein, and is collected by the water collecting mass 5 on the surface of the ground.

Furthermore, since the drainage reinforcement pile 4 of the present embodiment is an inclined drainage reinforcement pile cast in an inclined state with respect to the ground surface,
For example, even if the vibration in the longitudinal direction or the vibration in the lateral direction occurs during an earthquake, the compressive force and the tensile force in the horizontal or vertical direction are the compressive component force and the tensile component in the inclined axis direction of the drainage reinforcement pile 4. It acts as a force on the drainage reinforcement pile 4 and receives the resistance force of the drainage reinforcement pile 4.

FIG. 3 shows another embodiment of the drainage reinforcement pile of the present invention. For example, a rebar of about 13 mm having an outer diameter of about 150 mm is placed in a small-diameter long hole drilled in the sandy ground 1. A basket reinforcing bar 4c composed of a plurality of hoop muscles and a main bar connecting these hoop muscles is built, and crushed stones 4b having a size of about 25 mm or less are filled therein to form a pile diameter of about 200 to 250 mm.

The drainage reinforcement pile 4 of this embodiment also has resistance to pulling and compressing the ground 1 and a drainage function similarly to the piles of the above-mentioned embodiments, and since it is cast in the ground 1 at an angle, It has resistance to vibration in either direction.

FIG. 4 shows an example of construction in which the drainage reinforcement pile 4 of the present invention is placed in the liquefaction risk area A of the ground 1 of the tank 7 in an inclined state.

Further, the drainage reinforcement pile 4 of the present invention can be applied to a shallow (solid) foundation structure such as a retaining wall in addition to a tank.

FIG. 5 shows a construction example in which the drainage reinforcement pile 4 of the present invention is cast in an inclined state in the liquefaction risk area A of the support ground 1 of the structure 8 having the support pile 7.

As described above, since the sloped drainage reinforcement pile of the present invention is diagonally driven directly below the existing structure, it is possible to promptly drain excess pore water generated immediately below the structure to strengthen the ground. it can.

FIG. 6 shows an example of construction on a river embankment or road embankment 9, in which the drainage reinforcement piles 4 are laid in a state substantially orthogonal to the slope, that is, in an inclined state, and the corrugated pipe is exposed at the slope. Water is collected in the water collecting mass 5 by 10.

[Advantages of the Invention] 1) A deformed PC rod having an uneven surface, or a plurality of hoop muscles and main muscles connecting these hoop muscles, in a long hole drilled in a sandy ground Place the basket rebar,
Crushed stones were filled in the gaps between these deformed PC bars or cage rebars and the above long holes to resist the tensile and compressive forces of the sandy ground, so that earthquakes, etc. may occur and When the compressive force acts, the tensile force of the ground is transmitted to the deformed PC rods and cage rebars through the crushed stone, and these deformed PCs
The rods resist the tensile force etc. to restrain the sandy ground, suppress the generation of excess pore water pressure, and even if the excess pore water pressure rises, the drainage function of the crushed stone is exerted and the ground restraint is again performed. There is an effect that the function is restored.

2) Since it was constructed in a long hole diagonally drilled in the sandy ground, it has resistance to vibration in any direction and can not only strengthen the ground, but also above ground or underground. It can be easily constructed directly under or around the existing structure of, or in the ground with slopes such as river embankments and embankments.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of construction of a sloped drainage reinforcement pile on the ground of an underground buried object or a semi-underground structure, FIGS. 2 and 3 are diagrams showing various configuration examples of the sloped drainage reinforcement pile, and FIGS. FIG. 6 is a diagram showing another construction example of the inclined drainage reinforcement pile. 1 ... Sandy ground, 2 ... Buried object, 3 ... Semi-underground structure, 4 ... Drainage reinforcement pile, 4a ... Deformed PC rod, 4b ... Crushed stone, 4c ... Basket rebar, 5 ... Water collecting mass, 6 ... Tank, 7 … Support piles, 8… Structures, 9… Road embankments, 10… Corrugated pipes.

Front page continued (72) Kenzo Ochi 3-22-9-108 Kirigaoka, Midori-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Osamu Endo 2-13-12 Miyazaki, Miyazaki-ku, Kawasaki-shi, Kanagawa Prefecture (56) Reference Reference JP-A-60-250122 (JP, A) JP-B-56-47327 (JP, B2)

Claims (2)

[Claims] 1. A long hole diagonally drilled in a sandy ground,
A deformed PC rod with an uneven surface, or a cage rebar composed of multiple hoop muscles and a main bar that connects these hoop muscles is arranged, and crushed stones in the gap between these deformed PC rods or cage rebars and the long holes. A sloped drainage reinforcement pile for sandy ground, which is configured to resist tensile force and compressive force of sandy ground by being filled with. 2. The inclined drainage reinforcement pile for sandy ground according to claim 1, wherein the upper end portion is fixed to the surface ground by means of ground fixing means such as concrete.