JPH0634421Y2 - Device for measuring the tip position of tremie pipe when pouring concrete in water - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a tip position measuring device for a tremie pipe when pouring concrete into water, and particularly to a top end of concrete mixed with a separation reducing agent. The present invention relates to an apparatus for measuring the distance between the tip of a tremie tube for placing this and the position of the tip.

<Prior art> As is well known, for example, when constructing a concrete structure such as a continuous underground wall or a bridge leg, a tremie pipe is used as a method for placing concrete in the water or in the muddy water. There is a construction method.

In this construction method, it is an important requirement to obtain a high-quality concrete structure that the concrete to be poured is washed with water and the construction is performed without separating the constituent substances such as cement and aggregate.

By the way, in recent years, a special polymer compound has been added to concrete to increase the viscosity of the concrete, and underwater concrete in which constituent substances are hardly separated even when the concrete is washed with water has been developed and actually used.

When pouring this kind of underwater concrete by the tremie method, the viscosity of the concrete is large, so the tip of the tremie pipe was separated from the top surface of the already poured concrete, unlike the conventional method. It is possible to carry out continuous casting in a wide range because it can be carried out in a state.

However, in this type of underwater concrete, the separation is suppressed, but if the falling distance in water becomes too large, the constituent substances are separated and become a defect of the structure.

Therefore, it is desirable that the tremie pipe and the top end surface of the cast concrete be placed while maintaining a predetermined distance.

For this reason, conventionally, for example, as seen in Japanese Utility Model Laid-Open No. Sho 60-85332, an ultrasonic sensor is attached to the tip of the tremie tube, ultrasonic waves are projected onto the poured concrete, and the reflected waves are received. Although the distance between the tremie pipe and the top surface of the cast concrete was measured by, the measuring device like this had the following problems.

<Problems to be solved by the invention> That is, in the measuring device of the above publication, the ultrasonic sensor is arranged on the lower surface of the tip of the tremie pipe, but since the concrete discharged from the tremie pipe becomes mountain-shaped, its slope It was necessary to measure the part of, and the top surface could not be measured accurately.

In addition, the concrete discharged from the tip of the tremie pipe was discharged in a state in which some constituent substances were separated, which caused turbidity and bubbles in water, which hindered accurate top end measurement.

Furthermore, as the depth of casting concrete increases, the tremie pipe tilts due to the influence of tidal currents, etc.Therefore, if only the tip of the tremie pipe and the top of the cast concrete were measured, the intervals between them could be determined accurately. I couldn't do it.

The present invention has been made in view of such problems, and an object thereof is to provide an apparatus capable of accurately measuring the distance between the tremie pipe and the top end surface of the cast concrete.

<< Means for Solving Problems >> In order to achieve the above object, the present invention is directed to a top end of concrete to which a separation reducing agent is added and a tip position of a tremy pipe for pouring concrete. In a device for measuring the distance between and, an inclinometer installed on the side surface of the tremie tube, installed near the tip of the tremie tube, and inclined outward by a predetermined angle with respect to the axis of the tremie tube. An ultrasonic sensor that projects an ultrasonic signal, and receives a reflection signal from the concrete, and an output signal of the inclinometer and the ultrasonic sensor, receives the output signal of the tremie pipe and the concrete placed. The calculation device calculates the distance from the top surface.

<Operation> According to the measuring device having the above-described configuration, the ultrasonic sensor that projects ultrasonic waves on the placed concrete surface and receives the reflected signal thereof is inclined outward by a predetermined angle with respect to the tremie tube axis. Since it is installed as a result, it is not affected by the concrete discharged from the tremie pipe, turbidity, or bubbles.

Moreover, since the tremie pipe is provided with an inclinometer, its inclination angle is detected, and the detected value can be used to correct the distance between the tremie pipe and the top end face of the cast concrete.

<< Embodiment >> Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 to 4 show an embodiment of a tip position measuring device for a tremie pipe when pouring concrete in water according to the present invention.

The measuring device shown in the figure is used for concrete C that is placed through a hollow cylindrical tremie tube 10 to which a polymer-based separation reducing agent is added. Equipped with a plurality of two-axis inclinometers 12,12 installed at intervals along the axial direction, and a plurality of ultrasonic sensors 14,14 installed at intervals in the circumferential direction near the tip. There is.

The inclinometer 12 and the ultrasonic sensor 14 are connected to an arithmetic unit 15 installed on the ship.

The ultrasonic sensor 14 has a predetermined frequency, for example, 40
Ultrasonic waves with a frequency of ~ 400KHZ are transmitted in a predetermined cycle, for example, 200c
A transmitter / receiver 17 for transmitting the reflected wave from the concrete C is connected thereto so as to project the ultrasonic signal s with a predetermined angle outward with respect to the axis of the tremie tube 10. It is installed in.

As the ultrasonic sensor 14, a pressure resistant type is used, and the details of its mounting structure are shown in FIG.

The ultrasonic sensor 14 has a main body 14a formed in a cylindrical shape, and a mounting band 19 is attached to the outer periphery of the main body 14a with a cylindrical rubber protective plate 16, 16 interposed therebetween. The bracket 18 for mounting is fixed.

On the other hand, a fixed band 20 is mounted on the outer circumference of the tremie tube 10, and a pair of holding pieces 22 are provided on the fixed band 20 so as to project.

The ultrasonic sensor 14 is swingably attached so that the bracket 18 is inserted between the holding pieces 22 and the projection angle of the ultrasonic signal s can be changed by the bolt nut 24.

As shown in FIG. 1, the projection angle θ of the ultrasonic signal s is, for example, about 30 degrees if the mounting length l ₁ from the tip position of the tremie tube 10 is about 0.5 to ₁ m. In this case, , Directivity of the ultrasonic signal s from the central axis O of the tremie tube 10
When the angle was set to about 6 degrees, which spreads out to about 20 cm at a position of 1 m, a reflected wave with sufficient intensity to measure the tip position of the tremie tube was obtained.

Details of the arithmetic unit 15 are shown in FIG.

The computing device 15 includes A / D converters 26, 26 connected to the inclinometer 12 and the transceiver 17, respectively, a tilt angle signal θ ₁ converted into a digital signal by the A / D converters 26, and an ultrasonic sensor 14 and an arrangement. as an input signal and a signal t ₁ of time ultrasound reciprocates between the concrete C, tremie pipe 10 shown in FIG. 4
A microcomputer 28 for calculating the distance x between the tip of the concrete and the top surface of the cast concrete C and a display 30 for displaying the calculation result are provided.

The microcomputer 28 calculates the interval x by the procedure shown in FIG. 3 (b).

First, when the program starts, in step S1, the tilt angle signal θ ₁ and a plurality of reception signals t ₁ corresponding to the tilt angles are read, and in step S2, noise processing of each reception signal t ₁ , for example, the ultrasonic sensor 14 is performed. After emitting the ultrasonic signal s, the received signal is set to 0 level until a certain time,
Or cut the size of the received signal at a certain level,
Furthermore, after performing processing such as superimposing received signals to reveal noise signals and removing them, the waveforms of all received signals t1 are averaged in step 3 and correspond to the maximum output value of the averaged received signals. Then, the one-way time t obtained by halving this time is calculated.

Next, in step S4, the velocity v calculated based on the frequency of the ultrasonic signal s is multiplied by the one-way time t, and the ultrasonic sensor 14 and the top surface of the concrete C on which the signal s emitted from the ultrasonic sensor 14 are cast are applied. The distance l ₂ to the projected position is calculated.

In step S5, the distance l ₂ and the projection angle θ of the ultrasonic signal s
Then, the vertical distance l ₃ of the mounting position of the ultrasonic sensor 14 is obtained based on the tilt angle θ ₁ .

Then, in step S6, l ₁ cos θ ₁ is subtracted from the vertical distance l ₃ to calculate the interval x, and in step S7 the calculation result is output to the display unit 30 and the process returns to the start.

Now, in the tip position measuring device of the tremie pipe 10 configured as described above, the ultrasonic wave connected to the transceiver 17 which projects the ultrasonic signal s onto the cast concrete C surface and receives the reflected signal. Since the sensor 14 is installed so as to be inclined outward by an angle θ with respect to the axis O of the tremie pipe 10, the effect of concrete discharged from the tremie pipe 10 and turbidity,
Not affected by bubbles.

Further, since the inclinometer 12 is installed in the tremie pipe 10, its inclination angle θ ₁ is detected, and the detected value is used to measure the distance between the tip of the tremie pipe 10 and the top surface of the cast concrete C. It is possible to correct x so that the exact distance x can be measured.

<Effect of Device> As described in detail in the above embodiments, according to the device for measuring the tip position of a tremie pipe when pouring concrete in water according to the present invention, a separation reducing agent is added to the concrete to be poured. When added, it is not affected by turbidity or bubbles,
Also, since the inclination of the tremie pipe can be corrected, the distance between the tremie pipe and the top face of the concrete can be measured accurately.

[Brief description of drawings]

FIG. 1 is an overall explanatory view of the usage state of the device of the present invention, FIG. 2 is a detailed view of the mounting state of the ultrasonic sensor, FIG. 3 is a configuration diagram of the arithmetic unit and a flow chart diagram showing its processing procedure, and FIG. FIG. 4 is an explanatory diagram showing a relationship between a tip portion of a tremie pipe and a concrete top surface. 10 …… Tremy tube 12 …… Inclinometer 14 …… Ultrasonic sensor C …… Placement concrete s …… Ultrasonic signal θ …… Inclination angle

Claims (1)

[Scope of utility model registration request] 1. A device for measuring a distance between a top end of concrete to which a separation reducing agent is added in water and a tip position of a tremie pipe for placing concrete is installed on a side surface of the tremie pipe. And an inclinometer, installed near the tip of the tremie tube, projecting an ultrasonic signal by inclining outward by a predetermined angle with respect to the axis of the tremie tube, and
An ultrasonic sensor that receives a reflection signal from the concrete, an operation that receives the output signals of the inclinometer and the ultrasonic sensor, and calculates the distance between the tip of the tremie pipe and the top surface of the cast concrete. A device for measuring the tip position of a tremie pipe when pouring concrete in water, characterized by comprising a device.