JPH0359208B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for adjusting the lodging speed of a undulating weir made of a flexible membrane.

(Prior art) In a flexible membrane relief weir, an envelope (bag-like body) made of a flexible membrane (for example, rubber-coated cloth) forming the weir body is attached to at least the river bed in the direction across the river, and the envelope is A fluid, such as air or water, as an expansion medium is sent through an inlet/exhaust (water) pipe communicating with the inside to cause the enclosure to expand and stand up, and the fluid is discharged from the inside of the envelope to cause the enclosure to contract and fall down. (See No. 11702, Special Publication No. 44-2371).

If this type of undulating weir is an air expansion type, for example, when raising the weir as shown in Figure 1, the blower 1
is operated to inject air into the envelope 4 forming the weir through the air intake pipe 2 and the air intake/exhaust pipe 3 to erect the envelope 4 (see Figure 1a), and to form the envelope 4. When the water level upstream of the weir reaches the planned lodging water level 5, water enters the bucket 7 through the communication pipe 6 communicating with the upstream side of the weir (see Figure 1b), and when a predetermined weight is reached, the bucket 7 lowers and the rope Exhaust pipe 8 through 16
The weir formed by the envelope 4 was lowered by opening the lever-type valve 9 that communicated with the weir (see Fig. 1c).

(Problems to be Solved by the Invention) The discharge speed of air within the envelope 4 forming this weir is determined by the internal pressure of the weir formed by the envelope and the diameter of the exhaust pipe, and the discharge speed is not controlled. When the pressure inside the weir is high in the initial stage of lodging, the air inside the weir is discharged at high speed. For this reason, the weir height decreases significantly in the early stages of lodging, and the amount of water flowing downstream of the weir increases rapidly, which may cause damage to downstream river structures.

Especially in the case of air-inflatable weirs, V during the lodging process
Notch phenomenon (During the lodging process when the air inside the weir escapes, when the internal pressure of the weir falls below a certain value, a part of the weir top suddenly drops in a V-shape. 15 is a V-notch.)
This occurs (see Figure 2), and as shown in Figure 3, there is even more concern about water flowing downstream of the weir due to the V-notch phenomenon. In Fig. 3, the ○ mark indicates the internal pressure of the weir, the △ mark indicates the upstream water depth, the ▽ mark indicates the downstream water depth, A indicates the start of lodging, and B indicates the V-notch (right bank side).

Therefore, the present invention adjusts the discharge speed when discharging the air inside the envelope during the lodging process.
An object of the present invention is to provide an undulating weir made of a flexible membrane capable of controlling the lodging speed of the envelope and preventing a sudden increase in water flowing downstream of the weir.

(Means for Solving the Problems) That is, the method for adjusting the lodging speed of a flexible membrane undulating weir of the present invention involves moving the flexible membrane sheath forming the weir across the river at least to the river bed. In a weir that is installed in the direction of the envelope and is designed to send air into the interior of the envelope to cause it to expand and stand up, and to discharge air from the interior of the envelope to cause it to collapse, the weir is caused to lodge at a low speed during the initial stage of lodging of the envelope, and at the later stage of lodging. In order to adjust the lodging speed so that the lodging occurs at a high speed and prevent a sudden rise in water depth downstream of the weir at the time of lodging, a planned lodging water level detector, a weir internal pressure detector, and an electric motor installed in the middle of the discharge pipe linked to these were installed. It is equipped with a valve or electromagnetic valve, and at the early stage of lodging, the planned lodging water level is detected by a planned lodging water level detector, and the valve is half-opened to collapse the weir, and at the later stage of lodging, the weir internal pressure is detected by a weir internal pressure detector, and its value is detected. This system is characterized in that when the internal pressure near the V-notch phenomenon normally falls below 0.6 x weir height [mAq], the valve is fully opened to quickly complete the weir collapse.

The present invention will now be described in detail with reference to the embodiment shown in FIG.

In the case of the air expansion type, the one shown in Figure 4 is equipped with a detector for an abnormal collapse water level that is higher than the planned collapse water level and an electric valve or electromagnetic valve in the middle of the discharge pipe that is linked to this as an emergency collapse device in the event of an abnormal water outflow. The above-mentioned valve is used in common with the planned collapse water level gauge and the valve installed in the middle of the discharge pipe that is linked to the weir internal pressure detection. That is, in FIG. 4, the blower 1 is operated to inject air into the envelope 4 forming the weir through the air intake pipe 2 and the air intake/exhaust pipe 3 to make the envelope 4 stand up. When the upstream water level of the weir to be formed reaches the planned collapse water level 5, a solenoid valve or an electric valve 17 provided in the exhaust pipe 8 which is linked to the planned collapse water level detector 14 is opened to cause the weir to collapse. The inlet/exhaust pipe 3 and the exhaust pipe 8 connected thereto are relatively large diameter pipes, and the valve 17 is opened half-open in conjunction with the planned collapse water level detector.

On the other hand, the solenoid valve or electric valve 17 provided in the large diameter exhaust pipe 8 is connected to the weir internal pressure detector 11 provided in the envelope 4.
It also communicates with the abnormally collapsed water level detector 12, allowing the valve 17 to be fully opened.

(Function) With the above configuration, when the water depth upstream of the weir reaches the planned collapse water level 5 due to a flood, etc., the valve 17 of the exhaust pipe 8
Weir 4 is opened half-open to drain the fluid inside the weir.
The internal pressure detector 11 gradually collapses and prevents a sudden flow of water downstream, and after the collapse progresses and the weir reaches a V-notch state (internal pressure at Vnotch is usually 0.6 × weir height [mAq]), the internal pressure detector 11 The internal pressure is detected, and the valve 17 linked to this is fully opened to promptly lower the weir.

Furthermore, if a flood occurs suddenly and the lodging speed due to the exhaust from the half-open valve 17 cannot keep up with the increase in upstream water depth, the valve 17 is connected to a detector 12 that detects an abnormal lodging water level 13 higher than the planned lodging water level 5. Therefore, when the abnormal lodging water level 13 is reached, the valve 17 is fully opened to exhaust the air inside the weir and cause the weir to lodge. This results in
This prevents overflow floods caused by incomplete collapse of the weir upstream of the weir. Note that 10 in the figure is an air blow-off tank.

(Effects of the Invention) As described above, the flexible membrane undulating weir of the present invention is capable of adjusting the lodging speed so that the cover is lodged at a low speed in the initial stage of lodging, and at a high speed in the late stage of lodging. This structure prevents a sudden rise in water depth downstream of the weir when it collapses, and prevents damage to downstream river structures.

[Brief explanation of drawings]

Figure 1 is a schematic diagram showing a conventional undulating weir made of flexible membrane. Figure a is when the weir is erected, Figure b is when the weir upstream water level reaches the planned collapse water level, and Figure c is when the weir is collapsed. The figure shows the V that occurs when an undulating weir made of an air-inflatable flexible membrane collapses.
A front view to explain the notch, Fig. 3 is a diagram showing the internal pressure of the weir and fluctuations in upstream and downstream water levels during the weir collapse process of an air-inflatable flexible membrane undulating weir, and Fig. 4 is a diagram showing the fluctuation of the weir internal pressure and upstream and downstream water levels of the inflatable flexible membrane undulating weir of the present invention. Explanatory diagrams of undulating weirs are shown as examples. 1...Blower, 2...Air injection pipe, 3...Injection/exhaust pipe, 4...Encasing, 5...Planned collapse water level, 8...Exhaust pipe, 10...Air blow-off tank, 11...
...Weir internal pressure detector, 12...Abnormal lodging water level detector,
13... Abnormal lodging water level, 14... Planned lodging water level detector, 15... V notch, 17... Solenoid valve or electric valve.

Claims (1)

[Scope of Claims] 1. A flexible membrane envelope forming a weir is attached to at least a riverbed in a direction across the river, air is fed into the envelope to cause it to rise, and air is pumped out from inside the envelope. In a weir that is designed to discharge, contract, and lodge, the lodging speed is adjusted so that the cover is lodged at a low speed in the initial stage of lodging, and at a high speed in the late stage of lodging. In order to prevent the planned lodging water level from rising, the planned lodging water level detector is equipped with a planned lodging water level detector, a weir internal pressure detector, and an electric or electromagnetic valve installed in the middle of the discharge pipe linked to these.In the early stage of lodging, the planned lodging water level detector is used to detect the planned lodging water level. The valve is half-opened to allow the weir to collapse, and in the later stages of collapse, the weir internal pressure is detected by a weir internal pressure detector, and when the value falls below the internal pressure near the V-notch phenomenon (usually 0.6 x weir height [mAq]), the valve is fully opened. A method for adjusting the lodging speed of a flexible membrane undulating weir, characterized in that the lodging of the weir is completed promptly. 2. A flexible membrane envelope forming a weir is attached to at least the river bed in a direction across the river, and air is fed into the envelope to expand and raise it up, and air is exhausted from the interior of the envelope to cause it to contract and fall down. In order to prevent a sudden rise in water depth downstream of the weir at the time of lodging, the lodging speed of the weir is adjusted so that the weir is lodged at a low speed in the early stage of the cover lodging, and at a high speed in the late stage of lodging. It is equipped with a planned lodging water level detector, a weir internal pressure detector, and an electric valve or electromagnetic valve installed in the middle of the discharge pipe linked to these, and at the initial stage of lodging, the planned lodging water level is detected by the planned lodging water level detector and the valve is opened halfway. The weir is collapsed, and in the latter stages of collapse, the weir internal pressure is detected by a weir internal pressure detector, and if the value falls below the internal pressure near the V-notch phenomenon (usually 0.6 x weir height [mAq]), the valve is fully opened and the weir is collapsed immediately. In addition, an abnormal collapse water level detector higher than the planned collapse water level and an electric valve or electromagnetic valve in the discharge pipe linked to this are installed in the middle of the discharge pipe linked to the planned collapse water level detector and weir internal pressure detector. A flexible membrane undulation, which is provided separately or in common with the weir, and is characterized in that during an emergency period in the event of an abnormal water outflow, an abnormal collapse water level detector detects the abnormal water level and fully opens the valve to promptly complete the weir collapse. How to adjust the lodging speed of a weir.