JP2590008B2 - Automatic displacement measurement method for structures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial application field> The present invention relates to an automatic displacement measuring method for a structure for measuring the displacement of a structure, and more specifically, for example, measuring displacement when a bridge girder is erected, or completing a bridge girder. Management measurement with load test later,
The present invention also relates to an automatic displacement measurement method for a structure, which is suitable for measurement of settlement during preloading of ground improvement, or measurement of settlement of a large structure such as a storage tank or a large machine installation foundation.

<Prior Art> At present, there are various methods for measuring the displacement during the construction of various structures and the displacement after completion, but they are roughly classified as follows.

Contact measuring method A method of measuring the displacement of various structures using a dial gauge, tension meter, or other instrument.

Non-contact collimation measurement method Using a level, transit, and staff, the displacement of the structure or the structural or ground deformation by the cooperation of an assistant who moves or fine-adjusts the staff and a surveyor who collimates the level or transit How to measure subsidence.

C.C.D camera measurement method Measurement method using C.C.D camera.

<Problems to be Solved by the Present Invention> The above-described conventional measurement techniques have the following problems.

In the measurement method in <a>, an immovable place for mounting the instrument near each measurement point (hereinafter referred to as "immobile point")
is necessary.

Therefore, when it is difficult to obtain a fixed point, measurement becomes impossible.

In the case of <b>, the measurement method requires at least a plurality of workers.

Therefore, it is difficult to make the silicon work unattended, and it takes a relatively long time to obtain a measured value.

The measurement method of <c> is an expensive CCD for one measurement point.
Requires one camera.

 Therefore, as the number of measurement points increases, the measurement cost increases.

In the measurement method of <d>, a large number of measurement points cannot be measured simultaneously.

<Object of the present invention> The present invention has been made in order to solve the above-mentioned problems. The automatic displacement of a structure enables unmanned measurement and economical simultaneous measurement of many measurement points. It is intended to provide a measurement method.

<Configuration of the Present Invention> Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In this embodiment, a method of measuring the displacement of a bridge girder during construction will be described, taking as an example a case where the invention is applied to the construction of a cable-stayed bridge.

 First, the equipment used will be described.

<A> Laser Light Emitting Device The laser light emitting device 1 can use a known laser level or the like that emits a horizontally rotating laser beam.

Only one laser light emitter 1 needs to be installed at a fixed point.

<B> Light-Receiving Position Detecting Device The light-receiving position detecting device 2 is a combination of a large number of optical fibers and sensors. When a laser beam is received, it is detected as coordinates, and the detected data is output electronically. is there.

 One light receiving position detecting device 2 is installed at each measurement point.

<C> Measured value display means The wired area is wirelessly connected between the plurality of light receiving position detecting devices 2 and the management office near the site, and the data output from the two light receiving position detecting devices 2 is used as necessary for the CRT. Configure so that it can be displayed and printed out.

 These power transmission methods and display devices are based on known devices.

<Operation> The method of measuring the displacement of the bridge girder will be explained together with the construction of the cable-stayed bridge.

<A> Installation of laser emitter Figure 1 shows the construction site of the cable-stayed bridge.

First, in order to measure the displacement of the bridge girder to be erected, the laser emitter 1 is installed on the ground or at a fixed point such as a nearby pier or an existing girder.

When installing the laser light emitter 1, if the installation height is adjusted and installed so that the horizontally rotating laser light coincides with the planned erection line of the main girder, no special operation is required thereafter.

<B> Installation of girder 3 is a pier that has been assembled, and a main girder 4 is installed between the upper part of this pier 3 and neighboring piers 31 and 32.

For example, when a known cantilever method is adopted as a method of erection of the main girder 4, the blocks of the main girder 4 are sequentially extended symmetrically with respect to the blocks constituting the main girder 4 in a cantilever manner, and the main girder 4 is extended with the top of the pier 3. The oblique cable 5 is stretched between the blocks of each main girder 4.

When the block of the main girder 4 is extended with the cantilever, the free end of the main girder 4 is lowered by its own weight, and when the oblique cable 5 is tensioned at a certain interval, the free end of the main girder 4 is lifted.

 The main girder 4 is extended while repeating this.

<C> Installation of the light receiving position detecting device During the work of erection of the main girder 4, the light receiving position detecting device 2 is mounted vertically on each block of the main girder 4 requiring a measuring point.

<D> Displacement measurement When measuring the displacement of the main girder 4, the laser light emitting device 1 emits a horizontally rotating laser beam.

Then, a group of light receiving position detecting devices 2 attached to each block of the main girder 4 receives the laser beam.

Each position detecting device 2 receives a laser beam, converts it into an electric signal, and calculates the height of each measurement.

Then, the measured value of each measurement point is input to a computer or the like at a site or an office near the site.

The operator grasps the measured value of each measuring point displayed by the CRT display or the printout, that is, the displacement of the entire main girder 4 or the specific measuring point.

Based on the measured values, the main girder 4 along each design line is constructed.

As shown in FIG. 2, when the main girder 4 is finally extended, after adjusting the tension of the oblique cable 5, the both span end blocks 41 are constructed by suspending supports.

<Other Examples> The above-described example describes the case where the displacement of the bridge girder is measured.However, in addition to the above, the management measurement accompanying the load test after the completion of the bridge girder, or the settlement measurement during the preloading of the ground improvement, or the storage tank It can be applied to measurement of settlement of large structures such as foundations for installing large machinery and large machinery.

In the case of this embodiment, the laser light emitting device 1 is installed at a fixed point,
The measurement by installing the light receiving position detecting device 2 at each measurement point is the same as in the above-described embodiment.

When the installation direction of the light receiving position detecting device 2 is the vertical direction, the displacement in the horizontal direction may be measured by installing and measuring the laser light emitting device 1 so as to emit the laser light rotating in the vertical direction. Can also.

<Effects of the Present Invention> The present invention has the following effects.

<B> With the conventional non-contact measurement technology, it was impossible to measure a large number of measurement points at low cost.

According to the present invention, a large number of measuring points can be measured instantaneously and inexpensively while being non-contact type.

<B> No personnel are required for displacement measurement, and measurement values can be obtained at any time simply by turning the power on and off.

 Therefore, unmanned measurement can be achieved.

<C> Measurement values of many measurement points can be obtained instantaneously, and it does not take much time to obtain the measurement values.

<D> Since the measured values are electrically output, the measured values can be obtained anywhere, such as on the spot or in an office near the spot.

[Brief description of the drawings]

Fig. 1 is an explanatory view of one embodiment according to the present invention, and is an overall view of a measurement state when a bridge girder is overhanging. Fig. 2 is an overall view of a bridge when completed.

Continuation of the front page (56) References JP-A-48-14351 (JP, A) JP-A-63-219725 (JP, A) JP-A-62-232511 (JP, A) JP-A-61-239113 (JP) , A) Actually open sho 61-10512 (JP, U)

Claims (1)

(57) [Claims] When a laser light emitting device is installed at a fixed point in the vicinity of a structure that is displaced or deformed with time, the laser light emitting device scans horizontally to form a horizontal plane. At each measurement point on the side of the structure to be measured for displacement, a light receiving position detecting device that calculates the vertical light receiving position of the laser light and electrically outputs the light is installed, and emits light from the laser emitter. Automatic displacement measurement method for structures by receiving the rotating laser light in the horizontal plane with multiple light-receiving position detectors and instantaneously measuring the vertical displacement at many measurement points of the structure with respect to the fixed point