JPS6110698A - Crushing method by static crushing agent - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a crushing method using a static crushing agent for crushing objects to be crushed, such as concrete or rocks, using a static crushing agent.

(Prior art) When demolishing and crushing objects to be crushed such as concrete structures and rocks using a static crushing agent, the dominant factor of fracture is the expansion pressure of the static crushing agent in a direction perpendicular to the radial direction of the filling pipe. When the balance between this tensile stress and the tensile strength of the object to be crushed is lost, that is, when the applied tensile stress exceeds the tensile strength of the material, concrete, rocks, etc. will break.

Conventionally, when statically crushing an object to be crushed such as concrete, a filling hole is provided in the object by burying a filling pipe or by drilling, and a static crushing agent is filled into the filling hole. Static crushing is performed. Usually, the shape of the filling hole 3 is circular,
The arrangement is a grid pattern as shown in FIG. 6 or a staggered arrangement as shown in FIG. Furthermore, when the object to be crushed is circular, such as in the head treatment of a cast-in-place concrete pile, the filling hole by the filling pipe may be arranged in a circular, polygonal, or spiral shape.

Conventionally, the direction of crushing has been determined by moving the filling hole design position closer to the free surface of the object to be crushed, increasing the diameter of the filling hole, or narrowing the pitch of the filling hole in the crushing direction. and went on.

The important points in this case, such as the interval between the filling holes, the hole diameter, and the distance to the free surface, are determined empirically based on surrounding constraints and the like.

(Problem to be Solved by the Invention) However, in the past, the shape of the filling hole was circular, so the tensile strength acting on the surrounding area due to the expansion pressure acted equally on each cross section, making it difficult to control the direction of cracks. there were.

In addition, when planning the direction of cracks, it is necessary to narrow the gap between the holes or increase the diameter of the holes relative to the intended crushing direction, which may complicate the construction process or unnecessarily use the crushing agent. This had the disadvantage that the amount of material used increased, making it impossible to crush efficiently. Furthermore, the conventional method has the disadvantage that it is troublesome to select the diameter, spacing, etc. of the filling holes depending on the size and shape of the object to be crushed.

An object of the present invention is to provide a crushing method using a static crushing agent that allows for easy direction of crushing and efficient crushing.

(Means of the present invention for solving the problems) In the present invention, when providing filling holes in the object to be crushed, a plurality of holes are aligned and adjacent to each other in the direction in which crushing cracks are expected to occur, and are concentratedly provided. A static crushing agent is filled into the aligned holes to perform static crushing.

(Operation of the invention) When the filling holes are provided as aligned and concentrated holes in this way, the tensile stress when the static crushing agent is loaded is generated in the aligned direction of the holes,
It becomes easy to direct the fracture cracks.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an example of crushing a body 1 made of concrete, rock, etc. and having a rectangular cross section into hexagonal shapes. When it is desired to crush the object 1 into a hexagonal shape in this way, a plurality of filling holes 3 (in the example So 2
2) are arranged and arranged in a concentrated manner adjacent to each other along the planned fracture direction 2. A well-known static crushing agent is filled into each of the resulting concentration holes 4, and the static crushing agent is expanded to generate static crushing.

When static crushing is performed in this manner, stress concentration occurs in the direction in which the filling holes 3 are arranged, and crushing v1 occurs along the expected crushing crack direction 2, allowing hexagonal crushing.

The filling holes 3 can be filled with circular holes that are arranged in fractions, or two filling holes 3 can be arranged as aligned concentrated holes 4 as in the present invention.
Figure 2 shows the comparative results of crushing experiments when
In the figure, the horizontal axis represents the constraint condition, that is, the ratio of the distance to the free surface and the radius of the filling hole. However, in the case of an elliptical aligned and concentrated hole 4, the radius is determined as an equivalent circle. The vertical axis represents the ratio between the working average tensile stress d at the time of crushing and the tensile strength σ°C of the object to be crushed (concrete) at that time. From the figure, as the constraint condition k increases, the difference between the average acting tensile stress δ and the tensile strength σt is 5/σ
This indicates that t increases and approaches 1. Comparing a single circular hole and an aligned concentrated hole, the aligned concentrated hole has a slope that is about 1/2 gentler (X).This means that the tensile stress of the aligned concentrated hole is It is shown that it is about twice as likely to break as compared to the case of a single circular hole.

Moreover, FIG. 3 shows the experimental results of the relationship between the diameter of the filling hole 3 and the expansion pressure. As shown in the figure, it is 1, and the horizontal axis is time (
h), the vertical axis shows the pressure (kg/cm2 >), and the O mark indicates the pore diameter is 261111111△ the pore diameter is 20
Mark 110 indicates the state of intraocular pressure when the pore diameter is 16 mP, and the broken line indicates temperature. As is clear from the figure, it was found that there was almost no difference in the expansion pressure due to the difference in the size of the filling hole 3.

Therefore, by arranging and adjoining a plurality of small diameter holes, an effect equivalent to that of a conventional hole having an inner diameter equal to the sum of the diameters of the holes can be obtained.

FIGS. 4 and 5 show examples of the installation positions and orientations of the alignment concentration holes 4 when crushing the head of the cast-in-place concrete pile 5 by applying the present invention. In the figure, 6 is the reinforcing bar, 7t is the planned cutting surface, 8 is a concrete adhesion prevention pipe that prevents concrete from adhering to the reinforcing bar 6, and 9I is the tremie pipe insertion part.

(Effects of the Invention) As explained above, in the present invention, the filling holes are aligned and adjacent to each other along the expected direction of crushing cracks and are provided as aligned concentrated holes, so that the Fj F pressure of the static crushing agent is This causes a concentration of tensile stress due to this, and fracture cracks occur in that direction, making it easy to direct the fracture cracks. Further, according to the present invention, since stress is concentrated only in the direction of crushing and cracking, there is no concern that the expansion pressure will cause a negative shadow field in other parts of the object to be crushed. Furthermore, according to the present invention, not only can an aligned concentrated hole be evaluated as one circle equivalent to the sum of the inner diameters of its constituent holes, but also the pitch can be increased by twice the number of aligned holes, so static It is possible to save on crushing agent and shorten the time for forming holes. Further, according to the present invention, since it is only necessary to provide holes adjacent to each other, construction is simple, and by selecting the direction in which the holes are aligned, it is possible to crush any shape.

[Brief explanation of drawings]

Figure 1 is a plan view showing an example of the installation position and installation direction of aligned concentrated holes when hexagonal crushing is performed using the method of the present invention, and Figure 2 is the results of a crushing experiment using a single circular hole and an aligned central hole. Figure 3 is a diagram showing the relationship between expansion pressure and hole size, Figures 4 and 5 are diagrams showing the arrangement positions of aligned concentrated holes when the method of the present invention is applied to cast-in-place concrete piles. A plan view and a longitudinal sectional view showing examples of directions, and FIGS. 6 and 7 are plan views showing two examples of conventional filling holes. 1... object to be crushed, 2... intended direction of fracture cracking, 3... filling hole, 4... aligned concentrated holes. Patent applicant: Pentayo Construction Co., Ltd. Figure 1 Time (h)

Claims (1)

[Claims] In a crushing method using a static crushing agent, in which a filling hole is provided in the object to be crushed, a static crushing agent is filled in the hole, and the object to be crushed is crushed by the expansion pressure of the static crushing agent, the filling hole is used to prevent crushing cracks. The static crushing agent is characterized in that a plurality of static crushing agents are arranged and adjacent to each other along a predetermined direction, and a plurality of static crushing agents are provided in a concentrated manner, and the static crushing agent is filled into the resulting aligned concentrated holes to perform static crushing. A method of crushing using a crushing agent.