JP2000320294A - Sedimentary state monitoring method for earth and sand in sludge withdrawal pipe and stoppage prevention method for sludge withdrawal pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect whether or not there is an earth and sand sediment in a sludge withdrawal pipe and, at the same time, to facilitate the specification of a sedimentary place. SOLUTION: Electromagnetic flowmeters 4 and 5 are respectively arranged at the end positions of an earth and sand sedimentary state monitoring section of a sludge withdrawal pipe 2, at the same time, pressure gauges 61-6E for measuring pressure in the pipe are arranged n a sludge withdrawal pipe section held between the electromagnetic flowmeters 4 and 5, detection is made whether there is an earth and sand sediment in the sludge withdrawal pipe 2 based on relative difference of measured value information from the electromagnetic flowmeters 4 and 5 and measured value information from the pressure gauges 61-6E and, at the same time, the specification of an earth and sand sedimentary place is made.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to real-time monitoring of the sediment accumulation state of a mud pipe provided for transporting earth and sand excavated by a shield machine outside a mine in ground excavation such as shield excavation. The present invention also relates to a method for monitoring a sediment accumulation state in which sedimentation locations can be easily specified, and a method for preventing obstruction of a sludge pipe in order to prevent obstruction of the sludge pipe.

[0002]

2. Description of the Related Art For example, in tunnel construction using a full-section excavator such as a shield machine, a fluid transport pipeline for carrying excavated earth and sand out of a pit is provided along the pit. For example, in the case of a muddy shield or a muddy water shield, a mud pipe (water pipe) and a mud pipe (discharge pipe) are installed along the rear side of the tunnel while gradually extending as the shield machine excavates. It is connected to a mud (mud) treatment facility installed on the ground through a shaft.

[0003] In the former example of the muddy water shield, the muddy water sent from the muddy water treatment equipment to the shield machine by a mud pipe is composed of coarse particles from the excavated muddy water sent to the muddy water treatment equipment through a mud discharge pipe. After being classified, it is muddy water prepared and adjusted by bentonite, CMC (sodium carboxymethylcellulose), etc. Blockage in the pipe does not cause much problem, but the mud drainage pipe that transports muddy water containing excavated earth and sand Is larger than the diameter that is difficult to transport, such as 5
Gravel of 0 to 70 mm or more is removed in advance by a gravel separator or crushed to a diameter that can be transported, but other gravel is transported together with other excavated earth and sand and muddy water in the drainage pipe.

[0004]

In the case of shield excavated soil, besides the above-mentioned gravel, it is composed of various substances such as sand, silt, clay, water, air and other substances. The composition ratio changes drastically with the shield excavation, and the specific gravity, particle size composition, water content, etc. of the excavated soil inside the drainage pipe path differ for each pipe part, and further vary in the course of pumping and moving . And especially when the content of gravel is high, gravel is easy to separate inside the mud pipe route, and as a result, relatively large particles first settle and stay at the bottom of the pipe. In the worst case, there was a case where a pipe line was blocked. Once the pipeline is blocked, hundreds to thousands of meters
It became difficult to identify the blockage site from the exhaust pipes extending to a large extent, and it took a great deal of time and effort to recover.

Accordingly, a first object of the present invention is to monitor the state of sediment accumulation in a drainage pipe, to easily detect the presence or absence of sediment accumulation in a pipeline, and to easily identify the accumulation location. It is an object of the present invention to provide a method for monitoring the sedimentation state of sediment in a drainage pipe, which can be performed.

A second object of the present invention is to provide a method for preventing blockage of a drainage pipe, which prevents the blockage of a drainage pipe by applying the method of monitoring the state of sediment accumulation.

[0007]

According to a first aspect of the present invention, a flow meter based on a change in flow velocity is provided at least at a plurality of locations of a drain pipe at a distance. The present invention is characterized in that the presence or absence of sediment accumulation in the exhaust pipe is monitored based on the relative difference of the measurement value information by the meter.

[0008] For example, in an example using an electromagnetic flow meter typified by a flow meter based on a change in flow velocity, the electromagnetic flow meter measures an induced current generated in proportion to the flow velocity of a conductor passing through the inside of the flow meter. This is a flow measurement device that measures the flow rate by measuring the flow rate.If the muddy water is moving uniformly and uniformly in the drainage pipe, the flow rate value will be constant regardless of where the flow meter is installed in the pipeline. Become. However, once sedimentation occurs at a predetermined location in the drainage pipe, mud water, which has relatively low fluidity and is difficult to flow at the deposition site, flows down the surface of the sediment at a relatively slow speed, while relatively Mud water that has high fluidity and easily flows tends to preferentially flow down the upper part of the pipeline at a relatively high speed, so electromagnetic waves installed downstream of the section where the sedimentation occurs and the sedimentation point The measured value of the flow meter increases.

In view of the muddy water transport situation at the time of the sedimentation described above, if one electromagnetic flow meter installed downstream of the mud pipe is continuously monitored, the measured value of the electromagnetic flow meter becomes high. Can detect the accumulation in the pipeline,
Actually, the measured value of the electromagnetic flow meter fluctuates depending on the properties of muddy water transported in the mud pipe, and it is difficult to determine the presence or absence of accumulation based on the measured value of only one electromagnetic flow meter. That is, muddy water is gravel,
As described above, the material composition of sand, silt, etc. constantly changes.From the viewpoint of transportability, relatively large-sized earth and sand that easily accumulates at the bottom of the pipeline and relatively small-sized particles that easily flow at the bottom. The composition ratio is constantly changing depending on the nature of the excavated ground because of the mixture of earth and sand. The electromagnetic flow meter is affected by a substance having a relatively small particle size and a high flow velocity flowing through the upper part of the pipeline, and even if the actual flow rate is the same, the measurement value changes depending on the properties of the excavated earth and sand. It was difficult to determine the presence or absence of deposition based on the measurement value of one electromagnetic flow meter installed downstream of the pipe.

Therefore, in the present invention, a plurality of electromagnetic flowmeters are arranged at positions spaced apart from the drainage pipe, and the measurement value information from these flowmeters is compared to reduce the measurement error due to the muddy water condition. It is possible to accurately determine the presence or absence of accumulation in the pipe by canceling each other. For example, an arrangement mode as described below,
In other words, considering the case where a flow meter is installed at the end of the sediment accumulation monitoring section of the mud pipe, if the sedimentation in the pipe occurs, the measurement of the electromagnetic flow meter installed on the downstream side for the above-mentioned reason Higher values appear. At this time, since muddy water of the same nature is transported in the pipe, if the flow rate measurement value rises due to the influence of the muddy water state, the measurement value of the electromagnetic flow meter installed on the upstream side also Since the measured value of the electromagnetic flow meter installed on the downstream side should have risen, it is determined whether the reason for the increase due to the muddy physical properties or the multi-pipe sedimentation is on the upstream side. This is made possible by comparing the measured values with the installed electromagnetic flowmeter. That is, when there is a relative difference between the flow rate measurement values, it can be determined that the accumulation in the pipe has occurred, and when there is no relative difference, it can be determined that the influence is due to the muddy state.

Next, according to a second aspect of the present invention, there is provided a pressure gauge for measuring the pressure in the pipe at predetermined intervals along the drain pipe,
It is characterized in that the presence / absence of sedimentation and / or the location of the sedimentation in the mud pipe are specified based on the information measured by these pressure gauges. Assuming that sedimentation occurs in the drainage pipe, the downflow cross-sectional area in the pipe becomes smaller at this deposition point, and if the same amount of muddy water continues to be pumped, the pipe area decreases with the decrease in the pipe area at the point where deposition occurs. The pipe pressure increases. Therefore, by comparing and examining the pressure fluctuations of each pressure gauge installed in the mud pipe, the presence or absence of sediment accumulation in the mud pipe can be detected, and the location where sediment is accumulated can be quickly identified. become able to.

According to a third aspect of the present invention, a flow meter based on a change in flow velocity is provided at an end position of a sediment accumulation monitoring section of a drainage pipe, and the flow meter is sandwiched between the flow meters. A pressure gauge for measuring the pressure in the pipe at predetermined intervals is provided in the drain pipe section, and the sediment in the pipe is measured based on the relative difference between the information measured by the flow meters and the information measured by the pressure gauge. It is characterized in that the presence or absence of sedimentation and the location of sedimentation are specified. According to the third aspect of the present invention, the presence or absence of accumulation in the pipe is determined based on a relative difference of measurement value information obtained by the respective flow meters disposed at the end positions of the sediment accumulation status monitoring section, and identification of the accumulation location when accumulation occurs Is performed based on the measurement value information obtained by the pressure gauge. In this aspect, the number of installed flow meters can be minimized.

Next, a fourth aspect of the present invention for solving the second problem is a method for preventing blockage of a drainage pipe when transporting earth and sand excavated by an excavator together with muddy water. A flow meter and / or a pressure gauge is provided according to the deposition status monitoring method according to any one of claims 1 to 3 to monitor the sedimentation status of the sediment in the mud pipe, and measurement by the flow meter and / or the pressure gauge. At least one of at least one of the mixing amount of mud material mixed into the excavating head surface portion of the excavator, the shield excavation speed, the mud pumping capacity and the water injection amount is variably controlled based on the value. It is. One of the features of the method for monitoring the sedimentation status of the main soil is that it can monitor the sedimentation status in the pipes in real time. By variably controlling the mixing amount of the material and the like, it is possible to prevent the exhaust pipe from being blocked in advance.

It should be noted that the term “deposition” in the present specification includes the meaning of blockage of a pipe as a result of the progress of deposition.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing the arrangement of measuring instruments when the method for monitoring the state of sediment accumulation according to the present invention is applied to shield excavation.

In FIG. 1, excavation is performed at a face S by a shield machine (not shown), and the excavated earth and sand is transported to a mud treatment facility 3 disposed on the ground via a mud pipe 2. Here, after the coarse particles are removed, a part is formed and adjusted with bentonite, CMC (sodium carboxymethylcellulose) or the like, and sent again to the shield machine through a mud pipe. The rest is solidified and then disposed of. Note that the mud pipe is omitted in the figure.

The sediment excavated by the shield machine, after the gravel of a large diameter is removed by a not shown gravel classifier, installed in transportation starting end a discharge intermediate mud pumps P ₁ and the Haidorokan 2 Hydro pipe 2 by serially the installed plurality of discharge mud pump P ₂ to P _E at predetermined intervals
It is to be transported inside. Incidentally, as the discharge mud pump P ₁ to P _E, such as a centrifugal pump or Fukuren piston pumps 2-3 bladed is used to allow transport mud containing gravel coarse size in the normal high viscosity .

[0018] In this sedimentation condition monitoring system 1, the electromagnetic flow relative to multiple locations Haidorokan 2, a position near the transport starting end Hydraulic pumps P ₁ is installed in the specifically illustrated examples In addition to installing the electromagnetic flowmeters 4 and 5 at the position near the shaft,
The measured flow rate is input to the computer 10 installed in the management office 8 via the signal cable 7. Reference numerals 4A and 5A denote A / Ds for converting and amplifying analog amounts to digital amounts.
It is a conversion / amplification device.

Further, the electromagnetic flow meter pressure transmitter ₆ at predetermined intervals in the waste sludge pipe section flanked by 4, 5 1 to 6 _E
Is arranged, and the in-pipe pressure measured by each of the pressure transmitters 6 _{1 to} 6 _E is input to the computer 10 installed in the management office 8 via the signal cable 7. Further, the drainage pipe 2 has the pressure transmitters 6 _{1 to} 6.
_E Separately worker who is in underground directly from the pressure gauge 9 ₁ to 9 _n are arranged so as to be able visually measured value of the pressure in the Haidorokan 2. When the arrangement pitch of the pressure transmitter 6 and the pressure gauge 9 is small, the location of deposition in the sludge pipe 2 can be specified with high accuracy if the arrangement pitch is small. Are preferably arranged at intervals of about 100 to 200 m.

In the deposition status monitoring system 1,
If as shown in FIG. 2, when sedimentation occurs between the waste sludge pump P _n and the waste sludge pump P _E, of the drilling mud fraction is this the sedimentation point A transport, relative Since the mud water having the property of being easy to flow is almost liquid and flows down the upper part of the pipeline at a high speed, the flow velocity of the mud becomes higher at the downstream side than the sedimentation point A, and it is installed at the downstream side. The measured flow value of the electromagnetic flow meter 5 is increased. As described above, since the measured values of the electromagnetic flow meters 4 and 5 also change depending on the muddy water transported, the measured values are compared with those measured by the electromagnetic flow meter 4 installed on the upstream side. Similarly, when the flow rate measurement value is increasing, it is determined that the influence is due to the muddy state, and when only the downstream electromagnetic flow meter 5 is increasing compared to the measurement value of the upstream electromagnetic flow meter 4, It is judged that sedimentation has occurred in the middle of the pipeline.

[0021] The in section between the electromagnetic flow meter 4 and 5 are disposed a pressure transmitter 6 ₁ to 6 _E at a predetermined interval, the measurement value information of these pressure transmitter 6 ₁ to 6 _E By examining the pressure fluctuation in the pipe based on the above, the sedimentation point A can be specified. That is, as shown in FIG. 2, when sedimentation occurs between the waste sludge pump P _n and P _E, pipe pressure distribution pressure value is larger than the other portions A deposition occurs Therefore, the position of the deposition location A can be specified by finding a section where the pressure in the pipe is rising.

[Embodiment 1] FIGS. 3 to 6 show an actual shield excavation, in which an electromagnetic flow meter 4 is installed near the transport start end of a mud pipe 2 as shown in FIG. The electromagnetic flow meter 5 is installed in the
Pressure transmitter in 300~400m intervals 5 section between the units _{6 1}
Set up to 6 _E, by the electromagnetic flow meter 4 and 5 in parallel to the shield excavating monitors the inlet flow and outlet flow Haidorokan 2, monitors the pressure within the pipe by the pressure transmitter 6 ₁ to 6 _E shows the measurement graph when the verify measured values by the electromagnetic flow meter 4, 5 and the pressure transmitter 6 ₁ to 6 _E when tube deposition occurs how changes.
In addition, the measured pressure value shows only the measured value of the pressure transmitter _6n-1 in which deposition in the pipe actually occurred.

FIG. 3 shows the change over time in the flow rate of the electromagnetic flowmeters 4 and 5 when no accumulation in the pipe occurs, and FIG. 4 shows the change over time in the pressure transmitter 6 _n-1 when no accumulation in the pipe occurs. It shows a change in pressure. In FIG. 3 and FIG. 4, the ring number indicates a sludge pipe of unit length (about 1 m) connected in order from the shaft position (actually connected as a set of five pipes).
Are numbered in order from No. 1 and the measured value is
It shows that it is measurement data at the time of excavation. In addition,
Section of this No1015~1025 is a section of diluvial clay layer D _C2, a soil layer section of hesitation properties cause relatively tube deposition.

In FIG. 4, the "width of the pipe internal pressure value" is indicated on the horizontal axis because the double piston piston pump is used as the drainage pump, the pressure value increases when the piston is pushed in, and the pressure value constantly changes. This is because, due to the tendency, the pressure value is displayed with a difference between the maximum value and the minimum value of the pressure value when the ring number is installed. Of course, a graph may be formed using the maximum value of the measured pressure value.

First, in FIG. 3, the flow measurement value indicated by the bar graph is the measurement value of the electromagnetic flow meter 4 installed on the upstream side, and the flow measurement value indicated by the line graph is the electromagnetic flow meter installed on the downstream side. This is a total of 5 measured values. As can be seen at a glance from the graph, the measured values of the flow rates of the two are almost the same, and it can be seen that the accumulation in the pipe has not occurred. Also, the width of the pipe internal pressure value shown in FIG. 4 is substantially constant, and it can be seen that no pipe internal deposition occurs.

On the other hand, the measurement value data shown in FIGS. 5 and 6 shows the measurement data at the time of drilling prone diluvial sand D _S1 produce relatively tube deposition. As can be seen from the comparison of the flow measurement values of the electromagnetic flow meters 4 and 5 in FIG. 5, this is an example in which it is determined that deposition in the pipe has occurred because only the measurement value of the electromagnetic flow meter 5 installed on the downstream side has increased. . Also,
Looking at the measurement values of the pressure transmitters 6 _{1 to} 6 _E shown in FIG. 6, the pressure measurement data of the pressure transmitter 6 _{n -1} indicates that the width of the pipe internal pressure value has rapidly increased due to the occurrence of pipe internal deposition. depositing a section of the pump P _n to P _E is determined to have occurred.

As described above, when sediment accumulates at an arbitrary position in the mud pipe 2, a relative difference occurs between the measured values of the electromagnetic flow meters 4 and 5, so that the presence or absence of sediment accumulation in the mud pipe can be easily determined. It can be detected, and so deposited by pressure fluctuations of the installation to which the pressure transmitter 6 ₁ to 6 _E at predetermined intervals can be easily identify what locations occur.

As described above, the present invention has been described as a system for detecting the presence / absence of sediment accumulation in the sludge pipe 2 and specifying the piled position. However, the present method measures the situation inside the sludge pipe in real time, and Since it can be monitored, the amount of the mud material mixed with the muddy water into the excavation head surface of the shield machine is variably controlled based on the measurement value of the flow meter and / or the pressure gauge, thereby controlling the mud discharge pipe 2. Can be utilized also as a system for preventing the obstruction beforehand. As a specific method, a predetermined threshold value is set for the relative difference between the flow rate measurement values and the pressure measurement value. Improve fluidity and prevent tube deposition. The variable control target may be a shield excavation speed, a drainage pump capacity, a water injection amount, and the like in addition to the mud production amount.

Although the present invention has been described in the present specification by taking shield excavation as an example, in addition to shield excavation, TBM (Tunnel Boring Machining) in mountain tunnel construction may be used.
It can be applied to various kinds of muddy water transportation such as muddy transportation of excavated sediment from e) and muddy transportation of excavated sediment on underground diaphragm wall.

[0030]

As described above, according to the present invention, it is possible to easily monitor the presence or absence of sediment accumulation in the drainage pipe, and to easily identify the location where the accumulation has occurred.

Further, according to the application of the present deposition status monitoring system, according to the present deposition status monitoring method, it is mixed with earth and sand into the excavation head surface based on the measurement value of a flow meter and / or a pressure gauge provided in a drain pipe. By variably controlling the mixing amount of the mud making material or the like, it becomes possible to prevent the exhaust pipe from being blocked.

[Brief description of the drawings]

FIG. 1 is a diagram showing the arrangement of measuring instruments when a method for monitoring the state of sediment deposition according to the present invention is applied to shield excavation.

FIG. 2 is a diagram showing a pressure distribution in a pipe when the pipe deposition occurs.

FIG. 3 is a graph showing measured values over time of the electromagnetic flow meters 4 and 5 in the case where deposition in a pipe does not occur in Example 1.

FIG. 4 is a graph showing time-dependent measured values of a pressure gauge 6 _{n-1 in} the case where deposition in a pipe does not occur in Example 1.

FIG. 5 is a graph showing time-dependent measured values of the electromagnetic flow meters 4 and 5 when deposition in the pipe occurs in the first embodiment.

FIG. 6 is a graph showing time-dependent measured values of a pressure gauge _6n-1 when deposition in a pipe occurs in Example 1.

[Explanation of symbols]

 1. Deposition status monitoring system, 2. Drainage pipe, 3. Mud treatment
Equipment, 4.5, electromagnetic flow meter, 6₁~ 6_E… Pressure transmitter,
7 ... Signal cable, 8 ... Administrative office, 9₁~ 9 _n…pressure
Gauge, 10 ... Computer, P₁~ P_E… Sludge pon
Step

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Manabu Kurata 1-2 term Iwamotocho, Chiyoda-ku, Tokyo F-term (reference) in Kanto branch of Sato Industrial Co., Ltd. 2D054 AC04 AC05 DA12 DA39 GA63 GA73

Claims (4)

[Claims] 1. A flow meter based on a change in flow velocity is disposed at least at a plurality of locations of a drain pipe at a distance, and sediment deposition in the drain pipe is performed based on a relative difference between information measured by the flow meters. A method for monitoring the state of sediment accumulation in a sludge pipe, the method comprising monitoring the presence or absence of waste. 2. A pressure gauge for measuring the pressure in the pipe at predetermined intervals along the drain pipe, and based on information measured by the pressure gauge, whether or not sediment has accumulated in the pipe, and / or Alternatively, a method for monitoring the state of sediment accumulation in a drainage pipe, wherein a sediment accumulation point is specified. 3. A flow meter based on a change in flow velocity is disposed at an end position of a sediment deposition monitoring section of a drain pipe, and a pipe is disposed at a predetermined interval in a drain pipe section sandwiched between the flow meters. A pressure gauge for measuring pressure is installed, and based on the relative difference between the information measured by the flowmeters and the information measured by the pressure gauge, the presence or absence of sediment in the mud pipe and the location of the sediment accumulation are determined. A method for monitoring the state of sediment accumulation in a drainage pipe, characterized in that: 4. A method for preventing clogging of a drainage pipe when transporting earth and sand excavated by an excavator together with muddy water, wherein the method for monitoring a deposition state according to any one of claims 1 to 3 for a drainage pipe. A flow meter and / or a pressure gauge is disposed according to the above to monitor the sediment accumulation state in the exhaust pipe, and based on the measurement value of the flow meter and / or the pressure gauge, at least the excavator is mixed with the excavation head surface portion. A variable amount of at least one of a mixed amount of mud material, a shield excavation speed, a drainage pump capacity, and a water injection amount.