JPS5858492B2 - Method of penetrating a pipe using strain energy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (7) The invention relates to a method of penetrating a body into a body to be penetrated by a tube using strain energy.

Conventionally known methods for penetrating objects such as piles and sheet piles into objects to be penetrated, such as the ground, include impact driving methods using various hammers, vibration driving methods, press-in methods, and embedding methods.

Each of these methods has its own advantages and disadvantages; for example, the hammer driving method has the disadvantages of generating noise and vibration, and not being able to perform horizontal or diagonal driving.

The vibration driving method has the problem of insufficient driving ability and the inability to perform horizontal and diagonal driving, and the press-in method lacks penetration ability and requires a large reaction force device.

Furthermore, the embedding method has drawbacks such as a decrease in supporting capacity because the object to be penetrated is excavated first.

In order to improve these drawbacks of the conventional method, the applicant has already filed Japanese Patent Publication No. 49-5403 and Japanese Patent Application No. 52-5160.
No. 3 c% 1986-137509), patent application 1984-5
No. 1604 (Japanese Unexamined Patent Publication No. 137511/1989), patent application No. 1973
No. 2-82452 (Japanese Unexamined Patent Publication No. 54-18107) and Japanese Patent Application No. 53-90939 (c% Unexamined Patent Publication No. 55-19336) propose a construction method and device using strain energy.

This invention further develops these inventions described in E, and in particular, develops a method of penetrating the tube body symmetrically.A rib is provided inside the lower end of the tube body in advance, and a taper is provided inside the L@ portion of the tube body. One member is bitten into the other member to be coupled by frictional holding force, and a power device is interposed between the rib and the tapered member to apply a tensile load in the axial direction to give a tensile strain to the tube body, Furthermore, a tensile load exceeding the frictional holding force is applied to break the connection between the tapered member and the end of the tube body, and the tensile strain is applied to the hi portion of the tube body and is rapidly released. .

FIG. 1 explains one embodiment of the present invention, in which as a preliminary operation to impart tensile strain energy to the penetrating body itself,
This shows a state in which it is compressed in the opposite direction without any residue to maintain friction.

1 is a pipe body such as a steel pipe pile, and 2 is a penetrated body such as the ground.

A reaction force receiving rib 3 is provided in advance at the lower end of the tube body 1.

A high-rigidity adapter 4 is added to the outer periphery of the upper end of the head of the old tube body 1.

This adapter 4 is configured to be removable with bolts or the like, and is removed after the reed has been penetrated.

A strain energy applying and releasing mechanism 5 is placed on the head of the placing body 1.

This rock groove 5 consists of a piston 6, a rod 7, a tapered portion 8, and a hydraulic power unit 9.

A tapered portion 8 is formed in the lower part of the piston 6, and a portion of the tapered portion 8 enters into the tube 1 when the mechanism 5 is placed on the tube 1.

A tension grate 7a and a compression plate 7b are provided at the lower end of the rod 7, respectively, so that the reaction force receiver engages with the rib 3 when the tube body 1 is compressed by the piston 6 and during tension. It is composed of

PLAY) The distance between 7a and 7b is required to cover the jump of the mechanism 5 when strain energy is released.

In FIG. 2, the reaction force receivers are an example of ribs 3, and a plurality of ribs are provided at regular intervals in the circumferential direction of the tube body 1.

In this case, if the outer periphery of the compression plate 7b is cut out in a manner corresponding to the spacing between the ribs 3, the plate 7b can be cut into the ribs 3.
After loading from the bottom side, the plate 7b can be engaged with the rib 3 by appropriately rotating the rod I.

The strain energy applying and releasing mechanism 5 utilizes friction at a portion of the taper as a friction holding mechanism as described above, and therefore has a simple structure and low manufacturing cost.

Since friction retention and strain accumulation can be performed using a single spun cylinder, the cycle time is shortened and there are advantages such as not having to worry about variations in friction retention force.

When penetrating, Shirorad 7 is first moved by piston 6 without cutting.
is driven upward, the compression plate 7b and the rib 3 are engaged, and the tapered part 8 is further bitten into the upper end of the tube body 1, and the tube body 1 and the taper part 8 are separated by frictional force. Hold friction.

The high-rigidity adapter 4 is used to prevent deformation of the penetrating body 1 at this time, and at the same time to instantaneously release the frictional force, which will be described later.

Next, the piston 6 is reversely driven to extend the rod 7 downward, and the tension plate γa is engaged with the reaction force receiving rib 3 to apply a tensile load and accumulate tensile strain energy.

When this tensile load exceeds the frictional holding force between the taper part 8 and the end of the tube 1, the friction between the taper part 8 and the upper end of the tube 1 is released, and the tube 1 is moved to the upper end. The stress is released toward the lower end, and the accumulated strain energy is converted into velocity energy of the penetrating body, which applies an impact force to the tip of the tube body 1.

The tube 1 thereby penetrates into the body 2 to be penetrated.

At this time, the strain energy U accumulated in the tube body 1 is given by the following equation.

Here, P is the axial force 1 of the rod 7, the effective length e of the tube 1 is the elastic modulus of the tube 1, all'i, and the effective cross-sectional area of the tube 1. On the other hand, in this embodiment, the compressive strain energy U is also accumulated in the rod 7. This is given by 2LU=EA.

Here, the effective length E of the IJ rod is the elastic modulus A of the rod, the effective cross-sectional area of the rod The repulsive energy of the above u0U is distributed in inverse proportion to the mass M of the mechanism 5 and the mass m of the tube body 1 after stress release. It will be done.

Assuming that there is no resistance from the body 2 to be penetrated, the kinetic energy u' possessed by the tube 1 after release is given by u=cU+u )X M+m.

By continuously performing the above-described operations, the object to be penetrated is penetrated.

As explained above, in the present invention, since strain energy is accumulated in the tube body itself, the impact force of kinetic energy is directly applied to the tip of the penetrating body, and only the necessary minimum stress reflection according to the ground occurs, and furthermore, Since there is no striking surface, this is very advantageous in terms of energy efficiency and noise.

Furthermore, since the strain accumulation portion is the tube itself, the longer the tube, the more the amount of strain energy increases and efficiency increases.

Furthermore, since a dedicated strain energy storage body is not used, the height protruding above the tube body 1 is small and workability is good.

Since the impact stress generated in the splintered tube does not exceed the maximum stress at the time of strain accumulation, the tube itself is not damaged and can be driven in directions other than vertically.

Furthermore, since the upper and lower ends of the tube are restrained and a power device is interposed between them to apply a tensile load, a large tensile strain can be accumulated.

Since the upper end portion of the tubular body having a small diameter is held by frictional force, there is an effect that strain energy can be rapidly released and that strain can be imparted and released efficiently.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment of the method of the present invention, and FIG. 2 is an explanatory diagram of the structure of an embodiment of the reaction force receiving rib. In the figure, 1 is a pipe body, 2 is a penetrated body, 3 is a reaction force receiver is a rib, and 4
is a high-rigidity adapter, 5 is a strain energy imparting and releasing mechanism, and 6 is a high-rigidity adapter.
is a piston, 7 is a rod, 7a is a tension plate, 7b
8 is a compression plate, 8 is a tapered portion, and 9 is a hydraulic power unit.

Claims (1)

[Claims] 1 A rib is provided in advance inside the lower end of the tube, and a tapered member is inserted into the upper end of the tube and connected by frictional holding force, and a power device is interposed between the rib and the tapered member. By applying a tensile load in the axial direction, a tensile strain is applied to the tubular body, and by further applying a tensile load that exceeds the frictional holding force, the connection between the tapered member and the upper end of the tubular body is broken, and the tensile strain is applied. A method for penetrating a tube body using strain energy, characterized in that the bowing strain energy is suddenly released at the upper end of the tube body, thereby converting the bowing strain energy into interlocking energy and penetrating the body to be penetrated.