JP2023152471A - Sludge measurement system - Google Patents

Abstract

To provide a sludge measurement system capable of measuring a sludge amount in realtime with less error.SOLUTION: A sludge measurement system of the present invention comprises: an excavator 1 including a cutter chamber 3 having a cutter 2 for drilling sediment at a tip, a high concentration slurry supply tube 11 for pneumatically feeding high concentration slurry to the cutter chamber 3, a pinch valve 5 for intermittently discharging mud including excavated soil from the cutter chamber 3, a sludge receiving 6 for storing sludge M discharged from the pinch valve 5, a suction tube 13 connected to the sludge receiving 6 and for discharging the sludge M from the sludge receiving 6 to the outside of the pit, and a load cell 24 provided at the sludge receiving 6 and for measuring a weight of the sludge M discharged from the pinch valve 5; and an operation part electrically connected with the road cell 24 and for integrating the sludge weight of the number of times when a sludge valve is opened until reaching a predetermined excavation length and calculating the sludge weight at the predetermined excavation length.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present invention relates to a sludge measurement system that is applied to a mud thickening propulsion method for constructing pipes by underground excavation.

The mud-concentrated propulsion method involves pumping high-concentration mud into the cutter chamber of an excavator whose front part is sealed with a bulkhead, and then stirring and mixing the excavated soil and the high-concentration mud in the cutter chamber. By acting on the surface, the cutter stabilizes the face by maintaining mud pressure that opposes the earth pressure and water pressure, and the propulsion pipe is propelled and press-fitted by the driving force of the main push jack installed in the shaft. This is a method of constructing a culvert by using the pipes (Patent Document 1).

The excavated soil that has become mud in the cutter chamber is normally discharged to a mud receiving tray at the rear of the excavator using the pressure inside the cutter chamber. Next, the waste sludge is vacuum-transferred from the sludge receiver to the waste earth storage tank on the starting shaft and stored by a sludge suction and removal device installed on the ground.

In the mud propulsion method, if too much sludge is taken into the excavator during excavation, there is a risk of ground subsidence, so the amount of sludge must be appropriately managed. Generally, management is performed by measuring the amount of sludge stored in the sludge storage tank.

Patent No. 5537850

When the waste sludge in the sludge receiver is sent to the waste soil storage tank by vacuum transport, the sludge often remains in the pipe without being discharged, which causes an error in the amount of sludge removed. Furthermore, since the waste sludge in the waste earth storage tank is collected and carried out by a vacuum truck during construction, it is difficult to accurately determine the amount of removed sludge in real time.

An object of the present invention is to provide a sludge measuring system that has few errors and can measure the amount of sludge in real time.

The drainage measuring system of the present invention for solving the above problems includes a cutter chamber having a cutter at the tip for excavating earth and sand, a high concentration mud water supply pipe for pumping high concentration mud water to the cutter chamber, and excavated earth and sand. A sludge valve that intermittently discharges mud from the cutter chamber; a sludge receiver that receives the sludge discharged from the sludge valve; An excavator equipped with a sludge draining pipe for discharging the sludge, and a weight measuring device installed in the sludge receiver and measuring the weight of the sludge discharged from the sludge valve; electrically connected to the weight measuring device. and a calculation unit that measures and integrates the amount of sludge removed each time the sludge valve is opened, and calculates the amount of sludge removed in a predetermined excavation length.

According to the present invention, since the amount of sludge is measured at the time it is discharged from the cutter chamber to the sludge receiver, there is little error and the amount of sludge can be managed in real time, thereby reducing the possibility of taking in too much sludge. You can figure it out in time. Therefore, it is possible to prevent ground subsidence and perform safe construction.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing an example of a mud thickening propulsion method to which a sludge measurement system according to an embodiment of the present invention is applied. FIG. 2 is a cross-sectional view of the excavator showing a closed state of the sludge valve in the sludge measurement system according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of the excavator showing a state in which the mud removal valve is open. (a) and (b) are a plan view and a side view showing the mounting structure of the load cell provided in the mud receiving tray. (a) is an enlarged view of section A in FIG. 4(b), and (b) is a side view seen from direction B in FIG. 5(a). It is a flowchart which shows the measuring method of the amount of sludge using the sludge measuring system concerning one embodiment of the present invention.

Hereinafter, a sludge measurement system according to an embodiment of the present invention will be described. FIG. 1 shows an example of a mud thickening type propulsion method to which a sludge measurement system according to an embodiment of the present invention is applied.

In FIG. 1, reference numeral 1 indicates an excavator, and a cutter 2 (face) is attached to the tip of the excavator 1, and the cutter 2 excavates underground. A cutter chamber 3 sealed with a partition wall is provided at the tip of the excavator 1 in order to pressurize and fill with highly concentrated muddy water and dig while stabilizing the cutter 2. The excavator 1 excavates underground using the propulsion force of a main push jack 40 provided in the shaft 4, and presses a propulsion pipe 41 into the ground from a starting shaft mouth 42 to construct a culvert.
The high-concentration mud water is made by a mud-making device 9 outside the shaft 4, and is pumped to the cutter chamber 3 via a high-concentration mud water supply pipe 11 by a pump 10.

The excavated earth and sand is stirred and mixed with high-concentration muddy water in the cutter chamber 3 at the tip, plastically fluidized, and becomes high-concentration muddy water. Using the pressure difference between the cutter chamber 3 pressurized by this highly concentrated mud water and the excavator 1, the pinch valve 5 (sludge removal valve) is intermittently opened and closed, and the soil is removed into the mud removal receiver 6. Ru. As the pinch valve 5, for example, an air pressurized pinch valve can be used, and compressed air is injected into the valve body from the compressor 7 through the air hose 8, presses the rubber sleeve 51, and releases the fluid. Configured to block the flow. For example, by attaching a solenoid valve, a pressure reducing valve, etc. to the air hose 8, the pinch valve 5 can be remotely controlled.

The sludge discharged into the sludge receiver 6 is carried out to the outside of the shaft 4 by the sludge suction and discharge device 12 (vacuum generator) through the suction pipe 13 (suction hose) connected to the sludge receiver 6, and is discharged. The soil is sent from the soil container tank 14 to the waste soil storage tank 15. The waste mud stored in the waste soil storage tank 15 is carried out by a vacuum truck or the like, or transported and disposed of by a truck after being solidified. Exporting is normally carried out at appropriate times during construction.

A lubricant injection device 16 is provided outside the shaft 4, and the tail void (excess The excavated space (not shown) is filled with lubricant. Thereby, the frictional resistance between the excavator 1 and the ground can be reduced. Examples of the lubricant include conventionally used two-component solidified lubricants.

2 and 3 show the pinch valve 5 in the excavator 1 in a closed state and an open state, respectively. The cutter chamber 3 is connected to one end of a mud discharge pipe 19 for discharging the mud M in the cutter chamber 3, and the other end is connected to the pinch valve 5.
2 and 3, reference numeral 20 indicates a cutter motor for driving (rotating) the cutter. Further, reference numeral 21 indicates a bending jack for controlling the attitude and correcting the direction of the excavator.

As described above, the pinch valve 5 has the sludge pipe 19 connected to one end (sludge inflow side), and the emergency gate 22 and the discharge port 23 connected in this order to the other end (sludge outflow side). The emergency gate 22 is automatically closed during a power outage or emergency to prevent sludge from flowing in.
The discharge port 23 has a cylindrical shape, and is used to throw the waste mud M into the waste mud receiver 6 when the pinch valve 5 is open (see FIG. 3). The outlet 23 may have a downwardly curved elbow shape.
The sludge receiver 6 that receives the sludge falling from the discharge port 23 is constructed of a container with an open top surface, and a suction pipe 13 is connected to the side surface for discharging the stored sludge outside the mine. ing.

Next, a method for discharging the sludge M and a method for measuring the amount of sludge M will be explained based on FIGS. 2 and 3. As shown in FIG. 2, excavation by the excavator 1 is continued while supplying highly concentrated muddy water into the cutter chamber 3 with the pinch valve 5 closed. As a result, when the earth pressure inside the cutter chamber 3 reaches the upper limit, this is detected by a sensor (not shown), and the supply of compressed air is stopped by closing the solenoid valve attached to the air hose 8 of the compressor 7, and the pinch Open the sleeve 51 of the valve 5 and start discharging the waste mud M (see FIG. 3). The above-mentioned upper limit range of earth pressure refers to an area including the upper limit value of the earth pressure within the cutter chamber 3 and a value close to the upper limit value.

The sludge M discharged from the open pinch valve 5 due to the pressure inside the cutter chamber 3 passes through the emergency gate 22 and is thrown into the sludge receiver 6 from the discharge port 23. The thrown sludge M is discharged outside the mine through the suction pipe 13. When the earth pressure inside the cutter chamber 3 reaches the lower limit range, a sensor detects this and starts supplying compressed air by opening a solenoid valve, etc., and presses the sleeve 51 of the pinch valve 5. Close. The above-mentioned lower limit region of earth pressure refers to a region including the lower limit value of the earth pressure in the cutter chamber 3 and a value close to the lower limit value.

The pinch valve 5 can be opened or closed by an operator's operation or by an instruction signal from a control unit. The control unit detects earth pressure within the cutter chamber 3 and opens and closes the pinch valve 5. The amount of sludge discharged from the cutter chamber 3 is measured based on the opening and closing of the pinch valve 5, and it is managed whether the amount of sludge discharged is appropriate. This is because if the amount of sludge increases, there is a risk of ground subsidence due to the uptake of too much sediment.

In this embodiment, in order to manage the amount of sludge removed in real time, a load cell 24 (weight measuring device) is provided in the sludge receiver 6, as shown in FIGS. 2 and 3, for example.
FIGS. 4(a) and 4(b) are a plan view and a side view showing the mounting structure of the load cell 24 provided in the sludge receiver 6. FIG. As shown in the figure, the load cells 24 are attached to the four corners of the bottom of the mud receiving tray 6, which has a rectangular plane, and are electrically connected to the calculation section in the control section.
5(a) is an enlarged view of section A in FIG. 4(b), and FIG. 5(b) is a side view seen from direction B in FIG. 5(a).

5A and 5B show an example in which a beam type load cell is used as the load cell 24. In FIG. The load cell 24 is installed on the swivel foot 60. The swivel foot 60 is placed on a base 65 on which the mud receptacle 6 is installed, and is fixed with bolts 62 via an adjuster pad fixing plate 61. The load cell 24 is fixed by a bolt 64 to one part of the angle 63 which is fixed to the mud receiving tray 6 . The load cell 24 is connected to one end of a cable 66 for electrical connection to the calculation section.
Note that the load cells 24 are not limited to the four corners of the bottom of the mud receiving tray 6, and may be provided at, for example, three corners, two corners, the center of the bottom, etc. of the mud receiving tray 6, as long as they can receive the load of the mud receiving pan 6. It's okay.
Further, the load cell 24 is not limited to a beam type, and for example, a strain gauge type, a platform type, an S-shaped beam type, a canister type, a tension/compression type, etc. can be adopted.

Next, a method for measuring the amount of sludge in this embodiment will be explained with reference to FIG. 6. When the earth pressure in the cutter chamber 3 reaches the upper limit due to the excavation of the excavator 1, the solenoid valve of the pinch valve 5 is opened and a signal is sent. In response to a signal indicating that the solenoid valve is in the open state, weight measurement is started using the load cell 24 attached to the mud receiving tray 6. In the measurement, first, the weight (w1) of the sludge receiver 6 is measured when the pinch valve 5 is opened (before the start of charging of the sludge M). Since some sludge M remains in the sludge tray 6 that is the object of measurement without being discharged from the previous sludge removal operation, it is not possible to accurately calculate the amount of sludge removed using only the weight of the sludge tray 6 itself. Because you can't.

The calculation unit for measuring the volume of sludge basically uses the weight (w1) of the sludge receiver 6 measured before the start of charging the sludge M and closes the pinch valve 5 from the start of charging the sludge M. The weight (w2) of the sludge receiver 6 is measured, and the amount of sludge is calculated from the formula: w2-w1.

However, immediately after the pinch valve 5 is opened, the earth and sand (sludge) falls all at once into the sludge receiver 6, which may cause an impact load. Therefore, after opening the pinch valve 5, the measurement of the weight of the waste sludge M is started after waiting until the fall of the waste sludge M has calmed down (that is, excluding the initial stage of the start of feeding). Specifically, for example, the pinch valve 5 is opened and measurement is started after a predetermined period of time has elapsed (for example, after 2 to 5 seconds) from the start of inputting the sludge M, and all of the sludge M is in the sludge receiver 6. Measure the weight (w21) of the sludge receiver 6 when it enters.
The amount of increase in the sludge M is determined by the weight of the sludge receiver 6 when the pinch valve 5 is opened (w21) than the weight of the sludge receiver 6 when all the sludge M has entered the sludge receiver 6 (w21). The weight is obtained by subtracting w1). That is, the increased amount of sludge = w21 - w1. However, it is necessary to consider the weight of sludge carried out in 2 to 5 seconds (w22).

The weight (w22) of the waste sludge discharged from the suction pipe 13 during the predetermined time (for example, 2 seconds) from the start of the introduction of the waste sludge M is experimentally determined in advance. The weight (w2) can be obtained by adding the weight (w22) of the removed mud to the weight (w21) of the mud receptacle 6. That is, the formula: w21+w22=w2, and overall, the amount of sludge discharged can be measured by the formula: w21+w22-w1.

The time from opening the pinch valve 5 to starting weight measurement is sufficient time to avoid the influence of impact loads, and should be determined after checking the implementation status of the construction work. In other words, the time from opening the pinch valve 5 to starting weight measurement may vary slightly depending on the target soil quality, groundwater pressure, muddy water material, etc., so it is preferable to set it at the time of measurement. . Normally, it is appropriate to start measuring the weight (w21) 2 to 5 seconds after opening the pinch valve 5.

The weight (w22) of the waste sludge M is determined in advance. That is, since the sludge is always being carried out from the sludge receiver 6 through the suction pipe 13, it was experimentally carried out in advance to remove the sludge from the sludge receiver 6 through the suction pipe 13 at the beginning of the introduction of the sludge M (for example, for 2 seconds). The weight (w22) of the discharged sludge M is measured in advance. That is, the weight (w22) of the sludge M carried out from the sludge receiver 6 by the suction pipe 13 is, for example, when the pinch valve 5 is opened and all of the sludge M is in the sludge receiver 6. (Therefore, the opening and closing of the pinch valve 5) is stopped, and while suctioning and transporting the sludge M from the sludge tray 6 through the suction pipe 13, the amount of decrease in the weight of the sludge tray 6 every second is measured, and from now on the sludge is removed. The average weight reduction of the receiver 6, that is, the suction amount of sludge per second (kg/second) is determined. It is best to take measurements during actual construction. In this way, it is possible to know the weight (w22) of the waste sludge M at the initial stage of starting the introduction of the waste sludge M. For example, the weight (w22) of the sludge M for 2 seconds from the start of the introduction of the sludge M can be determined from the above-mentioned sludge suction amount (kg/sec) x 2 seconds.
Note that the removal of the sludge from the sludge receiver 6 may be linked to the opening and closing of the pinch valve 5. That is, when the pinch valve 5 opens, the removal of sludge from the sludge receiver 6 may be stopped, and when the pinch valve 5 closes, the removal of sludge from the sludge receiver 6 may be started. .
In addition, the weights (w1), (w2), and (w21) explained above all include the weight of the sludge tray 6, but after subtracting the weight of the sludge tray 6 from these weights, , the amount of sludge discharged may be calculated using the above formula.

While excavation continues while pumping highly concentrated mud water to the cutter chamber 3, the earth pressure reaches the lower limit area and the pinch valve 5 is closed, and then the earth pressure inside the cutter chamber 3 rises again and reaches the upper limit area. When this point is reached, the operation of opening the pinch valve 5, discharging the earth and sand (sludge) into the sludge receiver 6, and measuring its weight (w2) is repeated in the same manner as described above (see FIG. 6).
In this way, the continuous amount of sludge discharged as the excavator 1 excavates can be measured in real time. Therefore, a calculation unit electrically connected to the load cell 24 integrates the amount of sludge discharged each time the pinch valve 5 is opened. Then, the excavation length of the excavator 1 during that time is determined by measuring the jack stroke of the main push jack 40, and calculating the amount of sludge removal at a predetermined excavation length from the formula: cumulative sludge removal amount/excavation length. Able to control quantity. The measurement results of the amount of sludge can be displayed on a management monitor (not shown).
The predetermined excavation length is, for example, the length of one propulsion pipe or the length of one segment ring in the shield construction method, but may be other than that (for example, per 1 m of excavation length).

Moreover, it is preferable to convert the amount of sludge (weight) into volume and manage it. In the mud concentration method, (amount of excavated soil + amount of mud water injection - remaining amount of tail void) x 50% = amount of sludge removed, and the amount of sludge removed is often managed by volume. In order to convert into a volume, the specific gravity of the sludge is determined using a mud water hydrometer (mud balance), etc., and the sludge volume is obtained from the sludge weight/specific gravity in the calculating section.

If the measured amount of sludge discharged is higher than the desired setting range, the amount of earth and sand excavated is too large, so it is better to stop excavation and perform chemical injection. In addition, if the amount of mud discharged is lower than the desired setting range, the highly concentrated mud water sent to the cutter chamber 3 has penetrated into the ground and is evacuated, so take measures such as changing the material of the mud water. It is good to lecture.

The sludge M placed in the sludge receiver 6 is sucked and discharged outside the mine via the suction pipe 13 by the sludge suction and removal device 12.

According to the present embodiment, as described above, since the amount of sludge can be measured and managed in real time, it is possible to quickly determine whether too much sludge has been taken in or the like. Therefore, it is possible to prevent ground subsidence and perform safe construction.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various changes and improvements can be made within the scope of the present invention. For example, although the above-described embodiment is based on the thick mud propulsion method, it is similarly applicable to the thick mud shield method, the earth pressure propulsion method, and the earth pressure shield method. Further, in the above embodiment, the load cell 24 is used as a weight measuring device, but the present invention is not limited to the load cell 24, and various weight measuring devices can be used.

1 Excavation machine 2 Cutter 3 Cutter chamber 4 Shaft 5 Pinch valve (sludge removal valve)
51 Sleeve 6 Sludge receiver 7 Compressor 8 Air hose 9 Sludge making device 10 Pump 11 Sludge supply pipe 12 Sludge injection device 13 Suction pipe (sludge draining pipe)
14 Discharge container tank 15 Discharge storage tank 16 Slipping material injection device 17 Pump 18 Slipping material supply pipe 19 Sludge removal pipe 20 Cutter motor 21 Center bending jack 22 Emergency gate 23 Sludge removal port 24 Load cell (weight measuring device)
40 Main push jack 41 Propulsion pipe 42 Starting wellhead 60 Swivel foot 61 Fixing plate 62, 64 Bolt 63 Angle 65 Base 66 Cable M Sludge removal

Claims (5)

a cutter chamber having a cutter at its tip for excavating earth and sand;
a high-concentration muddy water supply pipe that pumps high-concentration muddy water to the cutter chamber;
a mud discharge valve that intermittently discharges mud containing excavated soil from the cutter chamber;
a sludge receiver for accommodating sludge discharged from the sludge valve;
a sludge drain pipe connected to the sludge receiver for discharging the sludge from the sludge receiver to the outside of the mine;
a weight measuring device installed in the sludge receiver and measuring the weight of sludge discharged from the sludge valve;
An excavator equipped with
A calculation that is electrically connected to the weight measuring device and calculates the weight of sludge at the predetermined excavation length by integrating the sludge weight of the number of times the sludge valve is opened until the predetermined excavation length is reached. A sludge measurement system equipped with a section and a. 2. The cutter chamber according to claim 1, further comprising a control unit that opens the mud removal valve when the earth pressure in the cutter chamber reaches an upper limit range, and closes the mud removal valve when the earth pressure reaches a lower limit range. Described sludge measurement system. When the calculation unit receives a signal indicating that the sludge valve is open, the calculation unit calculates the weight (w1) of the sludge receiver measured before the start of introducing the sludge, and the weight (w1) of the sludge receptacle measured before the start of introducing the sludge, and the operation of the sludge valve from the start of the introduction of the sludge. The sludge measuring system according to claim 1 or 2, wherein the weight (w2) of the sludge receiver is measured until it is closed, and the sludge weight is calculated from the formula: (w2)-(w1). The weight of the sludge receiver (w2) is the weight of the sludge at the initial stage of starting to add the sludge (w22), and the weight of the sludge during the period from the start of charging until closing the sludge valve, excluding the initial stage of starting the sludge charging. It is the sum of the weight of the sludge put into the mud tray (w21), and the weight of the sludge at the initial stage of the feeding start (w22) is the sum of the weight of the sludge thrown into the mud tray during the period at the beginning of the feeding start, which is measured in advance. The sludge measurement system according to claim 3, wherein the sludge measuring system is the weight of sludge discharged from the mud tray. 5. The sludge measuring system according to claim 4, wherein the initial period of starting to add the sludge is within a range of 2 to 5 seconds after the start of sludge feeding.

Images