JPH03224992A - Concrete placement method - Google Patents

Abstract

PURPOSE:To make execution of work easy by a method wherein sensor heads and reflecting boards are installed on both sides of a form timbering and on fixed points corresponding to them, and displacements measured with the above- mentioned instruments are displayed and concrete is placed according to the displayed displacements. CONSTITUTION:Sensor head 10, 10A, numbered five in total, are fixed to two positions on the underside on both the right and the left sides of a gantry 5 and to a position on the gable side of a tunnel. Reflecting boards 11, 11A are then provided, facing each of the sensor heads, and are fixed to the ground GL. Laser beams emitted from the sensor heads 10, 10A are reflected with the reflecting boards 11, 11A and the distance between each of the sensor heads and each of the reflecting boards is measured out of the time required for returning of the reflected beam. According to displacements confirmed by the above-mentioned measurement, quantity of concrete to be placed and the measured displacement of a form timbering are shown on a CRT, and speed and positions for concrete placement is then adjusted by visual observation of the display so that the displacements become roughly identical on both the right and the left sides of the form timbering.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a concrete pouring method for pouring concrete inner surfaces of substantially semicircular cross sections such as tunnel linings and arch bridges using formwork supports. It is something.

[Conventional technology]

Conventionally, when pouring concrete for a structure with a substantially semicircular cross section such as the one described above, as in the example of tunnel lining shown in Figure 1O, the concrete pouring space 2 in the excavated tunnel shaft 1 is
The formwork 3 is placed along the tunnel shaft 1.
Concrete is placed in the placing space 2 while supported by a formwork consisting of a gantry 5 and a turnbuckle 6 which are movably provided on rails 4 inside.

At that time, the amount of displacement of the formwork 3 and the above-mentioned formwork supports during concrete pouring is measured using the dial gauge 7, and the left and right pouring heights are visually checked using the inspection window 8 provided in the formwork 3. By doing so, a management method was used in which the concrete placement speed and placement position were adjusted.

However, the dial gauge 7 is very sensitive;
There are problems in that if a person or object touches the concrete during pouring work, measurements cannot be taken, it takes time and effort to read the gauge, and accurate control cannot be obtained.

[Problem to be solved by the invention]

The present invention was made in order to solve the above-mentioned conventional problems, and it is possible to reduce the amount of displacement of the formwork or formwork support when pouring the inner surface of concrete with a substantially semicircular cross section using the formwork support. The problem to be solved is to provide a concrete pouring method that allows concrete to be poured while reliably measuring and checking.

[Means to solve the problem]

As a means for solving the above-mentioned problems, the concrete placing method of the present invention includes a sensor head provided facing at least each point on both left and right sides of a concrete form support and a corresponding fixing point. Concrete is poured while displaying the amount of displacement of the formwork support measured by the reflector and confirming with a CRT and alarm device that these displacements are within the preset allowable displacement amount. The concrete placement speed and placement position can be adjusted as appropriate so that the amount of displacement of the formwork supports is approximately the same.

In addition, the sensor head fixed to the formwork support and the reflective plate provided corresponding thereto can be provided not only on both the left and right sides of the formwork support, but also on the toe side, the center, etc.
By providing a large number of photoelectric sensor devices each consisting of a sensor head and a reflector, highly accurate concrete placement can be achieved.

〔Example〕

Each embodiment of the present invention will be described below with reference to the drawings, and in each embodiment and the conventional example shown in FIG. 10, the same parts are indicated by the same part numbers.

First, in Embodiment 1 shown in the front view of FIG. 1, the plan view of FIG. 10 shows an example in which the method of the present invention is applied to concrete placement in a concrete placement space of a tunnel lining, similar to the conventional example shown in FIG.

Therefore, in this embodiment 1, as shown in FIG. 1, FIG. 2, and FIG. The sensor head 10.
Fix the IOA and these sensor heads 10.10A
For example, corresponding to the front of the d-50 to 70 fuselage in Fig. 3,
Each reflecting plate 11 is fixed on the ground G and L. IIA has been established.

For the sensor heads io and IOA, a distance-measuring photoelectric sensor composed of, for example, a semiconductor laser and a position detection element is used, and the sensor head 10. The distance d is measured by reflecting the IOA's laser beam and measuring the time it takes for it to return.

Next, as shown in FIG. 4, the sensor head 10.
A control box 12 that can arbitrarily set the allowable displacement amount of the formwork support measured by IOA, a display box 13 that displays these displacement amounts, and a printer 14 are provided. light 1
5 and alarm devices such as a buzzer 16, and a CRT 17 that displays the correlation between the amount of concrete placed and the amount of displacement of the formwork 3 or formwork support.

The amount of concrete placed in this case is determined by a concrete amount counter 18 that counts the number of concrete agitator trucks.

Therefore, each sensor head 10. If the amount of displacement measured by the IOA exceeds any one of the allowable displacements set in the control box 12, the above-mentioned alarm device is activated, and in this condition, the concrete The pouring will be done.

As a result, as shown in FIG. 5, the amount of concrete placed Q and the measured displacement amount F of the formwork support are displayed on the CRT 17, and by visually observing this, the amount of displacement F on both the left and right sides of the formwork support, The concrete placement speed and placement position are adjusted so that F2 and F2 are approximately the same.

At this time, check the pouring height H through the inspection window 8 of the formwork 3,
It is more preferable if the internal space displacement amount ΔS is measured with a tape measure, inputted, and displayed on the CRT 17 at the same time.

In FIG. 3, the legs of the gantry 5, which supports the formwork, are supported on the rails 4 via hydraulic jacks 9.

Next, the second embodiment shown in FIG. 6 is a front view, FIG. 7 is an enlarged front view of the central part of FIG. 6, and FIG. 8 is an enlarged front view of the main part on the right side of FIG. This is an example in which the method of the present invention is applied to the casting of arch concrete for an arch bridge, etc. In this second embodiment, reflective plates are placed at two points on the upper left and right sides of the form support 20 as shown in FIG. 11B, and sensor heads IOBs are installed at two fixed points on the upper left and right sides of the scaffolding 21 on the corresponding ground G and L, respectively.
Furthermore, a sensor head IOC is provided at a fixed point on the ground G, L below the center of the formwork support 20, and for this sensor head IOC, a sensor head is attached between the center of the formwork support 20 and the surface of the ground G, L. A piano wire 22 is stretched, and a reflection plate 11 is placed at a position facing the sensor head IOC, as shown in FIG.
C is fixed.

Also in the second embodiment having the above configuration, the first embodiment
Similarly, concrete is placed while displaying on the CRT 17 the amount of displacement on both sides and the center of the formwork support 20 obtained by each sensor head 10B and IOC, and the amount of concrete placed. The setting speed and placement position are adjusted. In this case, a relationship diagram between the concrete placement amount Vc displayed on the CRT 17 and the formwork support displacement amount SI is shown in FIG. The amount of displacement at the center is shown as F+ and Fz, and the amount of displacement at the center is shown as C0L.

Note that in the first embodiment, the sensor head 10, the IOA
are installed at each point on both the left and right sides of the gantry 5 that supports the formwork, and corresponding reflectors 11 and IIA are installed on the ground G and L.
On the other hand, in the second embodiment, the sensor head 10B and IOC are provided at the fixed points on the ground G and L, but these sensor heads 10. IOA, 10B
, IOC and reflector 11. IIA, IIB.

11C may be provided on either the formwork support side or the fixing point side.

〔Effect of the invention〕

As explained above, according to the concrete pouring method of the present invention, concrete can be poured while reliably confirming the amount of displacement of the concrete pouring formwork or formwork support. In the event of a problem, the concrete placement speed and placement position can be changed immediately.

In addition, when it is necessary to place concrete evenly on the left and right sides, such as concrete for arch bridges or concrete for tunnel lining, the amount of displacement of formwork or formwork support can be known at the same time, making construction easier. It has the advantage of becoming

[Brief explanation of drawings]

The drawings show various embodiments of concrete placement using the method of the present invention, and FIG. 1 shows embodiment 1 of the method.
2 is a plan view of FIG. 1, FIG. 3 is an enlarged front view of the right main part of FIG. 1, and FIG. 4 is a device configuration in Example I of FIG. 1. Figure 5 is a relationship diagram between the amount of concrete placed and the amount of measured displacement displayed on the CRT in Figure 4, Figure 6 is a front view showing the formwork support in Example 2, and Figure 7 is Fig. 6 is an enlarged front view of the central part of the main part of Fig. 6; Fig. 8 is an enlarged front view of the main part of the upper right part of Fig. 6;
Figure 9 is a relationship diagram between the amount of concrete placed and the amount of formwork support displacement displayed on the CRT in Example 2 of Figure 6. FIG. 3... Formwork, 5... Gantry, 6... Turnbuckle, 10. IOA, IOB, IOC...sensor head, 11. IIA, IIB, IIC...reflector,
17...CRT, 20...Form support, G, L.
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Claims (1)

[Claims] Displays each displacement amount of the formwork support measured by a sensor head and a reflector provided opposite at least each point on both the left and right sides of the concrete formwork support and the corresponding fixing point, and displays them. A concrete placement method in which concrete is placed while confirming that the amount of displacement is within a preset allowable amount of displacement.