JPS6295413A - Measuring method for crack variation - Google Patents

Abstract

PURPOSE:To grasp the shape of a crack accurately by measuring gaps among >=3 opposite surfaces by two measurement bases which are fixed to structure lumps bordered with a crack. CONSTITUTION:For example, a construction structure, etc., has a crack 10 and two structure lumps 12 and 14 are bordered with the crack. The 1st gate- shaped measurement base 16 which has an aperture part 18 is fixed tightly to one structure lump 12 with a bolt 16 and the 2nd measurement base 22 which is so structured as to enter the aperture part 18 of the 1st measurement base 16 with a margin is fixed to the other structure lump 14 tightly with a similar bolt, etc. Fitting holes 34x-34z for a displacement measuring instrument are bored in the raised part 24 of the 1st measurement base 16, the vertical piece 30 of the 2nd measurement base 22, and the lateral rack part 26 of the 1st measurement base 16, and tip measurement parts of dial gauges 32x-32z are inserted into those holes.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for measuring fluctuations in cracks that occur and progress due to various causes in various civil engineering and architectural structures.
More specifically, by attaching measuring bases that face each other on three or more different sides to each of the two structural blocks bordering the crank, and measuring the distance between them at any time, we can accurately measure three-dimensional fluctuations in cracks. It relates to methods that can be measured.

[Conventional technology] In structures such as civil engineering or architecture, new cracks may occur due to earthquakes, ground subsidence, water pressure, deterioration of materials such as concrete, or poor construction, or existing cracks (gaps or (including seams, etc.) may expand. Monitoring how these deformations progress and performing maintenance management to prevent structures from being destroyed is an extremely important issue in civil engineering. To this end, it is important to be able to measure crack fluctuations with extremely high accuracy of about 1/100 mm or less.

The conventional method for measuring the fluctuation of two structural blocks with the crank as a boundary is to fix bolts, etc. that serve as standards to both horizontal blocks, and to stretch Imphal wire, etc. between them. There is a method of measuring the relative displacement between the two points to which the bolt is attached based on the change in height. This method is based on the same principles as those used, for example, in landslide monitoring.

[Problems to be Solved by the Invention] The two structural blocks in a civil engineering building structure with a crank as a boundary do not move only in the direction in which the crank expands, but move three-dimensionally. Therefore, if the three-dimensional behavior of the structural block cannot be accurately known, appropriate maintenance and management of the structure cannot be performed.

However, the conventional method described above can only measure linear relative distance fluctuations between both reference points of two structural blocks. Therefore, there is a drawback that it is not possible to measure how much the structural block relatively moves in which direction.

In addition, the method of measuring the relative distance between two points by stretching wire rods has disadvantages such as the wire rods constantly appearing on the surface of the structure, which tends to cause troubles such as getting caught on something, and that management is troublesome. There is also.

The purpose of the present invention is to eliminate the drawbacks of the prior art as described above, to be able to accurately measure the three-dimensional relative displacement of two structural blocks bordering on a crack, and to provide stable measurement over a long period of time. An object of the present invention is to provide a method for measuring rack fluctuations that makes it possible to do so.

[Means for Solving the Problems] The present invention, which can achieve the above-mentioned objects, has two
A measurement base of a specific shape is fixed to each of the two structural blocks, and the system is characterized by the fact that no wires or the like are used.

Here, one measuring base is shaped with a recess or an opening, whereas the other measuring base is shaped like a recess or an opening.
It has a structure that allows it to enter the four parts or openings of the measurement base with plenty of room. The two measurement bases are in a relationship such that three or more different sides face each other, and are attached to two structural blocks with the crank as a boundary, as described above. The three-dimensional relative displacement of the two structural blocks is determined by measuring the spacing between the three or more opposing surfaces at any time, and crack fluctuations are measured.

[Operation] Since the two measurement bases are each fixed to two structural blocks bordered by a crack, if the structural blocks are displaced, the measurement bases will also be displaced accordingly. Since the two measurement bases face each other with a distance between them on three or more different sides, it is possible to accurately grasp the relative three-dimensional fluctuations of the two structural blocks by determining their relative distances. .

If two structural masses bordering on a crack change by a relatively small distance, it can be considered that there is only a relative translational change. The three-dimensional relative displacement can be determined by measuring the distance between the two.

However, if the fluctuations of the structural blocks are severe, the measurement base installation surfaces of the two structural blocks may undergo angular displacement due to uplift, subsidence, etc. with the crank as the boundary. In such cases, for example, it is possible to measure the inclination of the measurement base with respect to the vertical line, or to measure at three or more different points on opposing surfaces so that changes in angle between the opposing surfaces can also be measured.
It becomes possible to accurately grasp such intense movements of structural blocks.

[Embodiment] FIG. 1 is an explanatory view showing an example of a crack gauge to which the method of the present invention is applied, and FIG. 2 is an explanatory view showing the state during measurement. It is assumed that a crack 10 exists in a civil engineering structure or the like, and the crack 10 is divided into two structural blocks 12 and 14 with the crack as a boundary.

A concave first measuring base 16 with an opening 18 is firmly fixed to one structural mass 12 by bolts 20, and a concave first measuring base 16 with an opening 18 is firmly fixed to the other structural mass 14 in the opening 18 of the first measuring base 16. The second section has a structure that allows for easy entry.
22 is similarly firmly fixed with bolts or the like. When these first and second measurement bases 16 and 22 are installed in a place where temperature changes are severe, it is preferable to make them from a material with a small coefficient of thermal expansion, such as an amber alloy or ceramic. If it is installed in a place where temperature changes are small, such as deep underground, it may be made of ordinary metal.

The first measurement base 16 has a concave structure in which the upper ends of the two upright parts 24 are continuous with a horizontal frame part 26, and the second
The measurement base 22 includes an L-shaped part 28 whose tip enters into the opening within one day, and a hanging piece 3 erected from the tip.
It is of Ill structure with 0. These two measurement bases 16.22 face each other in three different directions. That is, the inner surface of one upright portion 24, the side surface of the L-shaped portion 28, and the horizontal portion 26.
, the surface of the hanging portion 30, the lower surface of the horizontal portion 26, and the upper surface of the L-shaped portion 28. For these 3 m long opposing surfaces, a displacement measuring device mounting section is formed in advance on one of the members.

Here, the upright part 24 of the first measurement base 16, the vertical piece 30 of the second measurement base 22, and the first measurement base 16
The displacement measuring device is installed in the hole 34x on the horizontal frame 26 of the
34y and 34z are provided, each with dial gauge 3
2x.

32)' and 32z are configured to penetrate. Therefore, in the above mounting, the holes correspond to the xyz rectangular coordinate axes shown in FIG.

Figure 2 shows a situation in which dial gauges are attached to the corresponding parts for measurement.

The distance between the inner surface of the upright portion 24 and the side surface of the L-shaped portion 28 (displacement in the X direction) is measured by the dial gauge 32x, and the distance between the side surface of the horizontal portion 26 and the surface of the hanging piece 30 is measured by the dial gauge 32y. The interval (displacement in the X direction) is measured,
Further, the distance (displacement in two directions) between the lower surface of the horizontal frame section 26 and the upper surface of the L-shaped section 2 is measured by the dial gauge 32z. Therefore, over time two structural masses12.
14 causes relative displacement, it becomes possible to accurately measure the three-dimensional variation of the crack.

If the crack fluctuations are relatively small, such measurements can be used to determine the relative fluctuations of the two structural masses with sufficient accuracy. However, if the crack progresses further and the surfaces of the two structural blocks, that is, the mounting surfaces of the two measurement bases, change so as to cause a relative angular displacement, errors in measurement will occur due to the influence of the rotation angle. . In such a case, as shown in Fig. 2, an angle detection mechanism 36 should be provided at one step 14.22 for each measurement, and the inclination of each measurement base surface with respect to the vertical direction should be measured in advance. For example, it is possible to grasp the angular displacement of the installation surfaces of both measurement bases, thereby making it possible to obtain accurate three-dimensional fluctuations.

FIG. 3 is an explanatory view showing another embodiment of a tarmac gauge to which the present invention is applied, and FIGS. 4A and 4B are a front view and a side view thereof, respectively. The basic idea is the same as in the previous embodiment. A first measurement base 42 is fixed to one structural block 12ζ bordering on the crack 10, and a second measurement base 44 is fixed to the other structural block 14. Here, it is firmly fixed with a weather-resistant adhesive material 46. In the first measurement step 42, an upright part 48 fixed to the structural block 12, a side plate 50 extending from the side surface thereof, and a top plate 52 projecting to cover them are continuously integrated, and a concave part is formed by them. In contrast, the second measurement base 44 is a rectangular parallelepiped block that can fit comfortably within the recess.

Therefore, in this case, the inner surfaces of the three plate-shaped portions constituting the first measurement base 42 and the outer surface of the second measurement base 44 face each other in three different directions. This embodiment is significantly different from the previous embodiment in that holes 54 are provided for mounting displacement measuring devices at three or more points that are not aligned in a straight line on each opposing surface. .

With such a configuration, 3
The distance can be measured point by point, making it possible to measure not only the distance between opposing surfaces but also the angular displacement. Therefore, for example, even if a crack progresses as shown in Fig. 5 and the two structural blocks change not only in parallel but also in an angular manner, as shown in Fig. 6, each of the opposing surfaces By inserting the dial gauge 32 at three or more points and measuring the distance, the distance between the facing surfaces can be determined including angular fluctuations, and all changes can be measured.

In this case, there is no need to provide an angle measuring mechanism as shown in FIG. 2, and changes in angle can be measured using only a displacement measuring device, so the structure of the measuring base is simple and can be said to be extremely preferable.

Although two embodiments of the present invention have been described in detail above, it goes without saying that the present invention is not limited to only such configurations. It goes without saying that the shapes of the first measurement base and the second measurement base can be changed in various ways. For example, the first
In the figure, the first measurement base may not have a gate-shaped structure but may have an inverted-shaped structure or a mouth-shaped structure. In short, it is sufficient to use a combination of measurement bases having portions that face each other in three or more different directions. As a displacement measuring device, in addition to a dial gauge, an actuating transformer, an optical displacement detector, etc. can also be used. In any case, as long as the measurement points on each measurement base are determined in advance, it is possible to simply measure crack fluctuations by bringing in one portable displacement measuring device and sequentially measuring the displacement.

[Effects of the Invention] As described above, the present invention is configured to measure the distance between opposing surfaces on three or more opposing surfaces with one pass to two measuring blocks each fixed to two structural blocks bounded by a wall and a wall. Therefore, it is possible to accurately measure the three-dimensional relative displacement of two structural blocks, and it is possible to accurately grasp the deformation of the crank, and to prevent damage to civil engineering and architectural structures caused by the crank. Since it can be prevented, maintenance management can be carried out appropriately, which is an excellent effect.

In addition, since the present invention only requires two measurement bases to be installed, stable measurement is possible over a long period of time, and measurement troubles are unlikely to occur. Maintenance of the measurement bases is also almost unnecessary, so the cost is low. This method has many excellent effects, such as not requiring any skill for measurement.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing one embodiment of a crank gauge to which the present invention is applied, Fig. 2 is an explanatory diagram showing a measurement situation using the crank gauge, and Fig. 3 is an explanatory diagram showing another embodiment of the tartar gauge according to the present invention. , Figure 4A is its front view, Figure 4B is its side view, Figure 5 is an explanatory diagram showing the state when the crank has expanded, and Figure 6 is an explanatory diagram showing the interval measurement situation at that time. be. 10... Crack, 12.14... Structural block, 16.
...first measurement base, 18...opening, 22...
Second measurement base, 32x, 32y, 32z...dial gauge, 34x, 34y, 34z...holes for mounting the displacement measuring device.

Claims (1)

[Claims] 1. A first measurement base with a recess or opening is fixed to one of the structural blocks bordering the crack, and a second measurement base with a structure that can enter the recess or opening with ample space is attached to a different one. The three-dimensional relative relationship between the two structural blocks can be determined by fixing them to the other structural block with a crack as the boundary so that they face each other on three or more sides, and measuring the distance between the two measuring bases at any time on the three or more sides. A method for measuring crack fluctuations characterized by determining displacement.