JPH05306599A - Decision method of stripping time of pressure welding concrete lining form device and stripping instruction device - Google Patents

Abstract

PURPOSE:To promote work efficiency and to reduce a construction period by making use of the fact that the strength of lined concrete bears the positive, interrelation with an integrating temperature of a form, and automating stripping time by a stripping instruction device. CONSTITUTION:A stripping instruction device 26 is constituted of an instrument 27, a memory operator 28, a controller 29 and an alarm 30. A tunnel peripheral temperature sensor 20 and form temperature sensors 21 and 25 are provided, and their lead wires are connected to the instrument 27 of the stripping instruction device 26. After that, an integrating temperature is calculated by the memory operator 28 on the basis of temperature data of the instrument 27. In addition, interrelation between the integrating temperature and the strength of concrete is derived in advance, and when it reaches the compressive strength of concrete lined from a correlative table, stripping of the form is instructed by the alarm 30. According to the constitution, decision on stripping time is automate<d, and work can be efficiently carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for accurately determining a demolding time of a formwork apparatus used for primary lining of a tunnel such as a mountain tunnel, and an apparatus used for the method.

[0002]

2. Description of the Related Art Conventionally, in a primary lining on an excavated wall surface of a mountain tunnel, a movable formwork device equipped with a crawler has been put into practical use instead of the spraying method. This formwork device uses a steel formwork along the excavation cross section along the excavation cross section for the reasons such as suppressing the generation of dust, which is a drawback of the spraying method, and eliminating the economic loss due to the rebound of aggregate etc. The mold is placed and filled with fresh concrete by pouring and filling in the gap between the ground and the mold, and the mold is demolded after the required strength is developed to form a smooth lining surface.

As a crimping concrete lining method for making a primary lining on the excavated wall surface of a tunnel using this formwork device, the applicant of the present invention has already disclosed JP-A-3-235899, JP-A-3-235898, and JP-A-4-23598. No. 64696. An example of the formwork apparatus 1 will be described with reference to FIGS. 4 to 5. A turntable 3 is rotatably mounted on a self-propelled crawler 2, and the turntable 3 includes a left-right jack 4 and an up-down direction. A directional jack 5 is provided, and at the rod tips of the jacks 4 and 5, form frames 6, 7 and 8 which can be expanded by the expansion and contraction of the jacks are hinged 9.
It is provided through.

The molds 6, 7 and 8 are provided with a required earth pressure gauge 10, a vibrator 11, a sample-collecting mold 12 and a pin 13 for early strength measurement. The strength development of the fresh concrete cast from the casting pipe 6a into the gap 15 between the excavation wall surface 14 and the surface of the mold is controlled.

[0005]

However, the strength of the above-mentioned cast concrete is measured, and after the predetermined strength is exhibited, the molds 6, 7 and 8 are removed from the excavation wall surface 14 of the natural ground 16 at the time of demolding. In order to determine, the concrete strength was measured by applying a load P to the early strength measuring pin 13 shown in FIG. 5 with a small jack or the like to repel a part of the lining concrete, and therefore the primary lining concrete However, there are drawbacks that some of them are destroyed and the work for pulling out the early strength measuring pin is troublesome.

The present invention has been made in view of the above problems, and provides a crimping concrete lining form device that does not destroy the primary lining concrete and can easily perform the work of inspecting the demolding time. It is an object of the present invention to provide a method for determining a demolding time and a device used therefor.

[0007]

The object of the present invention to solve the above problems and to achieve the above objects is to provide at least one temperature sensor for measuring the temperature of lining concrete on a formwork of a formwork apparatus. , Providing a temperature sensor for measuring the ambient temperature in the mine at the place where the lining concrete is placed, and calculating the integrated temperature from the numerical values of the temperature sensors,
When the integrated temperature reaches a numerical value corresponding to a predetermined compressive strength derived from the correlation table of the compressive strength and the integrated temperature, the mold releasing instruction is instructed. In addition, as described in claim 2, numerical data of at least one temperature sensor provided in the formwork of the formwork device and ambient temperature inside the mine at the place where the lining concrete is placed by the formwork device. Each of the numerical data of the temperature sensor for measuring is read by the measuring instrument, the integrated temperature is calculated by the storage arithmetic unit based on the numerical data from the measuring instrument, and the calculated numerical value of the integrated temperature is taken into the controller. This is because the demolding instructing device emits a trigger signal from this controller when the value reaches a value preset in the controller, and a signal for instructing demolding by the trigger signal is issued by an annunciator.

[0008]

According to the method for determining the demolding time of the crimping concrete lining formwork apparatus of the present invention, the measured data of the integrated temperature is collected, and it is covered with the desired compressive strength from the correlation table of the compressive strength and the integrated temperature. The non-destructive test can be used to judge that the work concrete has reached. Therefore, when the integrated temperature reaches a predetermined value, the mold device can be demolded. Also,
By using a microcomputer to issue a mold release instruction, the programming can be performed so that a signal is emitted when the integrated temperature reaches a predetermined value, so that the time of mold release can be automatically known. It will not be costly.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a demolding instruction device according to the present invention, and FIG. 2 is a perspective view showing a part of a temperature sensor attached to a mold. FIG. 3 is a correlation table of compressive strength and integrated temperature. In the figure, reference numeral 20 is a temperature sensor for measuring ambient temperature, 21, 22 ... 25 are temperature sensors for molds, 2 respectively.
6 is a demolding instruction device, 27 is a measuring instrument, 28 is a memory computing unit,
Reference numeral 29 is a controller of the computer, and 30 is an alarm.

In the method for determining the demolding time of the crimp concrete lining formwork device of the present invention, the strength of the primary lining concrete is estimated from the integrated temperature to determine the demolding time of the formwork of the formwork device. It is what Hereinafter, the apparatus and the like will be specifically described, and a method for determining the demolding time will be described.

First, as shown in FIG. 2, a mold temperature sensor 21 for measuring the temperature of the lining concrete is provided on the molds 6, 7 and 8 of the mold device 1 shown in FIG. For example, the mold temperature sensor is attached to the mold 6.
One for each of the left and right molds 7, 7 and one for each of the left and right molds 8, 8. In this way, a total of five mold temperature sensors 21 are attached to the molds 6, 7, and 8 which are developed in a substantially semicircular shape along the excavation wall surface 14.

Next, an ambient temperature measuring temperature sensor 20 (not shown) for measuring the ambient temperature inside the mine at the place where the lining concrete is placed is provided at an arbitrary position in the formwork apparatus 1. The outline of the demolding instruction device 26 will be described with reference to FIG. 1. One end of the lead wire of each of the temperature sensors 20 and 21 is connected to a connection terminal of a measuring instrument 27 of the demolding instruction device 26. The measuring device 27 converts the temperature measured by the temperature sensor into numerical data.

A storage computing unit 28 is connected to the latter stage of the measuring unit 27, and based on the temperature numerical data from the measuring unit 27, the storage computing unit 28 programmed with the following formula is used to calculate the integrated temperature. To calculate.

[0014]

[Equation 1]

In the above formula, Mx is the integrated temperature (° C.min) at the time of the x-th temperature data measurement, and Ti is i.
The temperature (° C) of the poured concrete at the time of the temperature data measurement, Toi is the ambient temperature (° C) at the time of the i-th temperature data measurement, and Δt is the time interval (mi) for measuring the temperature data.
n).

The integrated temperature calculated by the storage / calculation unit 28 is sent to the controller 29 connected to the subsequent stage of the storage / calculation unit 28 as data for each temperature measurement. Then, the controller 29 compares the preset integrated temperature (denoted by Ms) with the integrated temperature (Mx) from the storage calculator 28, and the integrated temperature Mx of the x-th time becomes Mx ≧ Ms for the first time. It is designed to emit a trigger signal when it is turned on.

The trigger signal is transmitted to the annunciator 30 connected to the subsequent stage of the controller 29, and the annunciator 30 is activated by the trigger signal to indicate that it is time to release the mold, for example, by blinking an annunciator lamp or The operator is informed by broadcasting from the speaker via the voice synthesizer, "It's time to leave the mold." In this way, the demolding instruction device 26 is configured.

Further, the setting of the integrated temperature in the control device 29 corresponds to the integrated temperature when the placed lining concrete has a desired strength from the compression strength-integrated temperature correlation table shown in FIG. The integrated temperature Ms is obtained. The vertical axis of this correlation table is the compressive strength σ (kgf / cm
² ), the horizontal axis is the integrated temperature M (° C · min).

The above-mentioned correlation table shows that, in a preliminary experiment, rapid-hardening concrete to be used for the primary lining of a tunnel was placed under predetermined conditions (ambient temperature 20 ° C.), and the concrete at each accumulated temperature up to 90 minutes was used. The compressive strength was prepared by collecting a cylindrical test piece (φ10 · 20 cm), measuring it with a compression tester, and plotting the compressive strength in a table. In the correlation table shown in FIG. 3, σx = 0.074
A linear correlation of Mx is obtained, and the correlation coefficient r ²
A high correlation of = 0.938 is recognized.
The numerical value of 0.074 shows the regression coefficient,
Depends on the hardening rate of concrete such as mixing conditions.

Therefore, a correlation table is prepared in advance for each temperature depending on the conditions of the tunnel internal temperature, and the integrated temperature corresponding to the desired compressive strength is obtained from each correlation table,
This integrated temperature value Ms is set in the controller 29. As described above, the present invention can be achieved by applying the integrated temperature method to the early hardening concrete in the primary lining of the tunnel.

Then, the demolding instructing device 26 is used as the formwork device 1.
The method of carrying out the primary lining of the tunnel by equipping with the above is explained. After excavating the natural ground 16 for a predetermined length, the formwork apparatus 1 is moved by itself to a place for primary lining, and along the excavated wall surface 14. The molds 6, 7 and 8 are expanded in a semicircular shape with the jacks 4 and 5. Next, the rapid hardening concrete is poured into the gap 15 from the casting pipe 6a. After the rapid-hardening concrete is filled in the gap 15, the demolding indicator 26 is operated, and the integrated temperature Mx is calculated based on the temperature data obtained from the temperature sensors 20, 21, ... 25, for example, at intervals of 2 minutes.

Then, when the integrated temperature Mx when measured a plurality of times becomes Mx ≧ Ms, the demolding instruction device 26.
A signal is emitted from the alarm device 30. From this, the operator found that the rapidly-hardened concrete that had undergone the primary lining had reached the desired compressive strength, and operated the jacks 4 and 5 of the formwork apparatus 1 to demold the formwork 6, 7 and 8. The formwork apparatus 1 is retracted to another place. It should be noted that the formwork device may be either a movable formwork or a fixed formwork form device.

[0023]

As described above, the method for determining the demolding time of the crimping concrete lining formwork apparatus of the present invention is such that at least one temperature sensor for measuring the temperature of the lining concrete is attached to the formwork of the formwork apparatus. If more than one is provided, a temperature sensor is provided to measure the ambient temperature inside the mine at the place where the lining concrete is cast, and the integrated temperature is calculated from the numerical values of the temperature sensors, and when the integrated temperature reaches a predetermined numerical value. Since it is designed to instruct the demolding of the formwork, it does not require the operator to know the time of demolding without destroying the lining concrete surface as in the past, and the work is efficient and the construction period is It also shortens. Moreover, since the lining concrete surface is not destroyed in part, a clean finish is obtained.

By using the demolding instruction device, it is possible to automatically know the demolding time by setting the integrated temperature in the controller in advance, and the laborious integration calculation work can be completed in a short time. It will improve the efficiency.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a mold release instruction device according to the present invention.

FIG. 2 is a perspective view showing a part of a temperature sensor attached to a mold.

FIG. 3 is a correlation table of compressive strength and integrated temperature.

FIG. 4 is a front view, partly in section, showing a usage state of a formwork apparatus according to a conventional example.

FIG. 5 is a partial cross-sectional view showing a usage state of the early strength measuring pin.

[Explanation of symbols]

20 Ambient temperature measuring temperature sensors 21, 22, ... 25
Mold temperature sensor, 26 mold release indicator, 27 measuring instrument, 28 memory calculator, 29 computer controller, 30 alarm.

Claims (2)

[Claims] 1. A formwork of a formwork apparatus is provided with at least one temperature sensor for measuring the temperature of lining concrete,
A temperature sensor for measuring the ambient temperature inside the mine at the place where the lining concrete is placed is provided, the integrated temperature is calculated from the numerical values of the temperature sensors, and the integrated temperature is derived from the correlation table of the compressive strength and the integrated temperature. A method for determining the demolding time of a crimping concrete lining formwork device, characterized by instructing demolding of a formwork when a numerical value corresponding to a given predetermined compressive strength is reached. 2. Numerical data of at least one temperature sensor provided on the formwork of the formwork device and a temperature sensor for measuring the ambient temperature inside the mine at the place where the lining concrete is placed by the formwork device. Each of the numerical data is read by the measuring instrument, the integrated temperature is calculated by the storage arithmetic unit based on the numerical data from the measuring instrument, and the numerical data of the calculated integrated temperature is taken into the controller and preset in the controller. A demolding instruction device characterized in that a trigger signal is issued from this controller when the specified value is reached, and a signal for instructing demolding by the trigger signal is issued by an annunciator.