JP3571997B2 - Mud water supply and drainage device in propulsion method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sheet HaiSo location mud in jacking method, particularly, among the jacking method utilized for laying construction of sewage pipe, mud and supplying muddy water to the excavating surface excavated earth and sand is discharged together with the muddy water directed to a equipment to be used for supply and discharge of the mud in the jacking method.
[0002]
[Prior art]
The muddy water propulsion method facilitates excavation by supplying muddy water to the ground to be excavated by the leading conductor. In addition, by mixing the excavated earth and sand with muddy water, the fluidity is improved and the water can be efficiently discharged. By applying the muddy water pressure to the excavated surface of the ground, the ground of the excavated surface can be collapsed, and groundwater can be prevented from flowing into the leading conductor, thereby stabilizing the face.
In a general muddy water propulsion method, a muddy water tank for storing muddy water is provided on the ground surface, and a muddy water supply pipe is extended from the muddy water tank to a buried pipe through a shaft. The muddy water supply pipe which extends the inside of the buried pipe to the leading conductor is opened to the pressure chamber from a partition arranged in front of the leading conductor. A drilling machine that rotates with a drilling bit and the like is arranged in front of the pressure chamber. A pump driven by a motor or the like is mounted in the middle of the muddy water supply pipe to pump muddy water. A muddy water discharge pipe is connected to the partition wall of the leading conductor, and sediment excavated by the excavator is taken in together with the muddy water. The mud discharge pipe is arranged from the shaft to the mud tank on the ground surface through the inside of the buried pipe, and the sediment and mud return to the mud tank. A pump is also installed in the middle of the muddy water discharge pipe to pump soil and muddy water. The mud tank is provided with a mud treatment device for separating mud and sediment, and the mud from which the sediment is separated is sent back to the mud supply pipe.
[0003]
[Problems to be solved by the invention]
In the above-described muddy water propulsion method, it becomes difficult to supply and discharge muddy water as the propulsion distance increases.
For example, when discharging muddy water with a muddy water discharge pipe, the muddy water and sediment are sucked up from the front of the tip conductor, which is the tip of the muddy water discharge pipe, through a muddy water discharge pipe inside the buried pipe by a pump installed on the ground surface. In such a case, the suction pressure (negative pressure) of the pump becomes extremely large. As a characteristic of the pump, since it is difficult to generate a large negative pressure, the ability to suck in muddy water and sediment on the excavated surface of the leading conductor is weakened. In particular, if muddy water alone is not a serious problem, the presence of earth and sand in addition to the muddy water increases the passage resistance in the muddy water discharge pipe, so that the pump pressure or capacity must be further increased.
[0004]
Note that there is a practical limit to the magnitude of the negative pressure that can be generated by pumps and pipes. Even if used, the discharge of muddy water and sediment becomes virtually impossible.
Therefore, a pump for discharging muddy water should be placed at the leading end of the conductor or buried pipe line, and the muddy water and sediment sucked into the muddy water discharge pipe should be pumped under positive pressure to the mud tank on the ground via the buried pipe at the back. Can be considered. In the case of positive pressure, there is no limitation as in the case of the negative pressure, so that muddy water and sediment can be discharged only by using a large-capacity pump.
[0005]
However, the internal space of the buried pipe and the leading conductor in the propulsion method is extremely narrow, and it is difficult to install a large-capacity or large-sized pump.
Therefore, by disposing a large number of relatively small pumps at intervals inside the buried pipe, it is possible to discharge muddy water and sediment over long distances even if the capacity of each pump is low. Has been proposed. The installation intervals of the pumps vary depending on conditions such as soil conditions, muddy water concentration, and pipe diameter, but are usually provided at intervals of about 200 to 300 m. Since the total length of the muddy water propulsion method may exceed 1000 m, pumps must be installed in several places or more in the total length of the buried pipe row.
[0006]
However, no matter how small the pump is, if a large number of pumps are arranged in a narrow space inside the buried pipe at intervals, workers who inspect, operate, survey, etc. the tip conductor will move inside the buried pipe In such a case, it is necessary to move over the positions of a large number of pumps, so that the burden on the operator becomes excessive. In addition, it is troublesome to check and repair a large number of pumps that are scattered in the buried pipe. Further, when the buried pipe is added with the progress of the propulsion method, it is necessary to sequentially install a pump together with the muddy water discharge pipe, which greatly reduces the workability of the propulsion method.
[0007]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a muddy water propulsion method as described above, which can solve problems such as a decrease in workability due to installing a large number of pumps in a buried pipe, and can efficiently supply and discharge muddy water. .
[0008]
[Means for Solving the Problems]
A muddy water supply / discharge device according to the present invention is a leading method in a propulsion method in which a ground is excavated with a leading conductor to form a burial hole, and the leading conductor and a buried pipe connected behind the leading conductor are propelled into the burial hole. It is a device that supplies muddy water to the excavated surface of the ground by the body, and discharges excavated earth and sand together with muddy water, and the muddy water supply pipe laid from the outside of the buried hole through the inside of the buried pipe to the excavated surface of the leading conductor A muddy discharge pipe laid from the excavated surface of the leading conductor to the outside of the buried pipe through the inside of the buried pipe, and a pump means that is disposed in the middle of the muddy water supply pipe and the muddy water discharge pipe and pumps the muddy water, at least A pump means arranged in the muddy water discharge pipe has a base arranged inside the buried pipe, a plurality of sets of pumps arranged in front and rear on the base and motors for driving the pumps, and an upstream side Connect the pump outlet to the downstream A tandem pump device having a connection pipe for connecting the inlet of the pump.
[Muddy water propulsion method]
In the propulsion method, while excavating the ground with a leading conductor to form a buried hole, the leading conductor and a buried pipe connected behind the leading conductor are propelled into the buried hole.
[0009]
In the muddy water propulsion method, muddy water is supplied to the excavated surface of the ground by the leading conductor, and the excavated earth and sand is discharged together with the muddy water.
Basic working equipment, working procedures, working conditions, and the like of the muddy water propulsion method may be the same as those of the ordinary muddy water propulsion method.
The leading conductor used in the muddy water propulsion method is provided with a bulkhead behind the excavator arranged on the front side, muddy water is supplied to the pressure chamber, which is the space between the bulkhead and the excavator, and the excavated earth and sand is muddy. It is discharged with.
The muddy water supply pipe is arranged from the outside of the burial hole to the excavation surface of the leading conductor, that is, the pressure chamber through the inside of the buried pipe. The muddy water discharge pipe is arranged from the excavated surface of the leading conductor, that is, the pressure chamber, to the outside of the buried pipe through the inside of the buried pipe.
[0010]
The muddy water supply pipe and the muddy water discharge pipe are connected to muddy water treatment equipment installed on the ground surface or in a shaft, outside the buried pipe. The muddy water treatment equipment can be provided with a muddy water treatment device that separates only muddy water from a mixture of muddy water and earth and sand sent from a muddy water discharge pipe, a storage tank for storing processed muddy water, and the like.
In the middle of the muddy water supply pipe and the muddy water discharge pipe, pump means for pumping muddy water is provided.
As the pumping means, as long as muddy water or muddy water containing earth and sand can be pumped, a pumping means in a usual muddy water propulsion method can be used in combination. A tandem pump device is used as a part of this pump means.
[0011]
[Cascade pump device]
As long as the base can support a plurality of sets of pumps and drive motors and has a dimensional structure that can be installed inside a buried pipe, a structure similar to a support plate or a base in a normal mechanical device can be adopted. . Usually, it can be configured by combining a steel plate or a shaped steel material.
On the base, a plurality of sets of pumps are arranged adjacent to each other in front and rear. Each pump is provided with a motor for driving the pump. If the rotation centers of a plurality of sets of pumps and drive motors are arranged on the same axis, the overall outer diameter can be made approximately the same as the outer diameter of a single pump and drive motor.
[0012]
As the pump, a normal muddy water pump or a sand pump is used. However, when the pump pressure generated in the whole cascade pump device becomes high, it is preferable to make the withstand pressure of the pump high. Specifically, it is effective to mount a high pressure-resistant mechanical seal at a position where the liquid and the rotating shaft slide in the pump. A mechanical sheet that can be used at a pressure of, for example, 0 to 1 MPa is used. It is desirable that the upstream pump of the plurality of pumps has a higher withstand pressure than the downstream pump.
It is preferable that the inside space of the pump through which earth and sand and gravel pass has a flow path diameter through which gravel can pass. It is desirable that the protruding portion of the internal space be rounded or cut off. If a relatively large area inspection lid is provided to facilitate the discharge of gravel or the like when the internal space is clogged, it is easy to open the inspection lid and take out the gravel or the like. If the inspection lid is provided at the position of the impeller of the pump, it is easy to take out gravel or the like caught on the impeller.
[0013]
The plurality of sets of pumps are connected by using a connection pipe from a discharge port of an upstream pump to a suction port of a downstream pump. It is desirable that the connecting pipe be arranged along the outer shape of the pump so as not to protrude outside the outer shape of the pump as much as possible.
It is desirable that the total length of the tandem pump device is not longer than the entire length of the buried pipe in which the tandem pump device is installed. Usually, it is preferable that the length of the buried pipe is shorter by about 50 cm than the entire length.
A pair of support bars may be provided on the base of the cascade pump device to facilitate the work of attaching, detaching, and moving the cascade pump device inside the buried pipe. The support bar is arranged at intervals in parallel with the axial direction of the buried pipe, and has a cylindrical shape with both ends rounded. The pair of support bars can be connected by a support frame member disposed therebetween. When the tandem pump device is installed in a buried pipe, the support bar is arranged so as to abut against the inner surface of the buried pipe. Sliding the support bar along the inner surface of the buried pipe facilitates movement and position adjustment of the tandem pump device.
[0014]
Wheels and casters may be attached to the base to facilitate movement of the cascade pump device.
The tandem pump device can be installed in both the muddy water supply pipe and the muddy water discharge pipe. However, if there is no problem even if the pump means is installed outside the buried pipe, an ordinary pump can be used. Therefore, the tandem pump device requires the pump means to be installed inside the buried pipe. Alternatively, it is preferable to adopt a location where performance and workability can be improved by installing a pump means inside the buried pipe.
Specifically, it is preferable to employ a tandem pump device as the pump means of the muddy water discharge pipe. If the tandem pump device is arranged at a location near the excavation surface of the leading conductor in the muddy water discharge pipe, the suction pressure acting from the excavation surface to the tandem pump device can be reduced. A tandem pump device with a high pump pressure can pump muddy water over a long distance through a buried pipe to a muddy water treatment facility installed on the ground surface or the like.
[0015]
When the propulsion distance in the muddy water propulsion method, that is, the number of connected buried pipes increases, the tandem pump device can be installed also in the muddy water discharge pipe in the middle of the buried pipe row. Even in this case, the number of installation points of the pumps is reduced as compared with the case where a large number of single pumps are installed as in the related art, and the operation in the buried pipe is less hindered.
When two pumps are combined as a cascade pump device, the installation interval of the pump means can be extended to about twice or more as compared with the conventional method using the pump alone. For example, an installation interval can be set to only 200 to 300 m with a single pump, whereas an installation interval can be increased to 500 to 800 m with a tandem pump device using two pumps.
[0016]
A protective cover can be attached to the tandem pump device. For the protective cover, a relatively thin metal plate, a metal mesh plate, a synthetic resin material, or the like can be used. By attaching the protective cover, it is possible to prevent a worker from being caught on a member of the tandem pump device inside the buried pipe, and to prevent a work tool or the like from hitting and damaging the tandem pump device.
If a lifting hook is attached to the tandem pump device, the carrying and installation work of the tandem pump device become easy.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
[Muddy water propulsion method]
The embodiment shown in FIG. 1 shows the entire configuration of a muddy water propulsion method employing the muddy water supply / discharge device of the present invention.
In the propulsion method, work is performed in a shaft H excavated from the ground surface to the ground E. The leading conductor 10 is fed from the side wall of the shaft H to the ground E in the horizontal direction. A buried pipe 20 made of a fume pipe or the like is sequentially connected to the rear of the leading conductor 10 and is propelled together with the leading conductor 10.
[0018]
The propulsion of the leading conductor 10 and the buried pipe 20 is performed using a propulsion jack 60 installed in the shaft H. Although not shown, if the tip of the propulsion jack 60 is extended forward in a state where the tip of the propulsion jack 60 is pressed against the rear end of the buried pipe 20, the propulsion jack 60 moves from the propulsion jack 60 to the buried pipe 20 and the tip conductor 10. And propulsion.
At the same time as the propulsion by the propulsion jack 60, the ground E is excavated at the tip of the leading conductor 10 by rotating the excavator 12 having the excavation bit on the front surface. During this excavation work, muddy water is fed into the space between the excavator 12 and the partition wall 14 on the back side thereof, that is, into the pressure chamber 16. The pressure of the mud suppresses the collapse of the ground E and the infiltration of groundwater, and stabilizes the face. Since the earth and sand excavated by the excavator 12 is mixed with the muddy water, the muddy water is discharged from the pressure chamber 16 so that the earth and sand can be discharged together with the muddy water.
[0019]
When one buried pipe 20 is propelled to the ground E, a new buried pipe 20 is sent from the surface to the inside of the shaft H, and a new buried pipe 20 is installed at the end of the buried pipe 20 being propelled. In the same manner as described above, the propulsion work by the propulsion jack 60 is performed. By repeating such operations, the buried pipe 20 fed into the ground E extends. When the leading conductor 10 reaches a target shaft previously set, a series of propulsion methods is completed.
[Supply and discharge of muddy water]
The muddy water supply and discharge will be described in detail.
[0020]
A muddy water supply pipe 40 and a muddy water discharge pipe 30 are provided from the shaft H to the ground surface through the inside of the leading conductor 10 and the buried pipe 20. The distal ends of both the pipes 30 and 40 open from the partition wall 14 of the leading conductor 10 to the pressure chamber 16.
The muddy water discharge pipe 30 extends rearward and is connected to a muddy water treatment device 50 installed on the ground surface. The muddy water treatment device 50 separates the earth and sand contained in the discharged muddy water, and sends the muddy water excluding the earth and sand to the adjusting tank 52. The muddy water is stored in the adjustment tank 52. In the adjusting tank 52, a chemical for adjusting the viscosity and components of the muddy water is added.
The muddy water supply pipe 40 is connected to the adjustment tank 52. A mud feed pump 42 is installed at a position near the adjusting tank 52 of the muddy water supply pipe 40. Since the mud pump 42 is installed on the surface of the ground with a limited space, a pump having a general structure may be used according to the required capacity and capacity. When the mud pump 42 is operated, the mud stored in the adjustment tank 52 is supplied to the pressure chamber 16 of the leading conductor 10 through the mud supply pipe 40.
[0021]
In the muddy water discharge pipe 30, the tandem pump device 100 is mounted inside the buried pipe 20 connected immediately behind the leading conductor 10. The tandem pump device 100 sucks muddy water and earth and sand from the pressure chamber 16 of the leading conductor 10, and sends muddy water and earth and sand to the muddy water treatment device 50 through the muddy water discharge pipe 30. Since the distance between the cascade pump device 100 and the pressure chamber 16 of the leading conductor 10 is short, the cascade pump device 100 does not need to generate a large negative pressure.
In the middle of the muddy water supply pipe 40 and the muddy water discharge pipe 30, valves 34, 44, a bypass pipe, and the like are provided as necessary.
[0022]
[Cascade pump device]
FIG. 2 shows a detailed structure of the tandem pump device.
In the cascade pump device 100, a pair of pumps 110 having the same structure are installed on a base 140. The pump 110 is a centrifugal pump, and has a suction port 114 at a central position and a discharge port 112 at an outer peripheral position. In the structure of the pump, a mechanical seal having a high pressure resistance is mounted at a position where the liquid and the rotary shaft slide, so that application of a high pressure to the pump 110 does not cause any trouble. An inspection lid 116 for observing the inside of the pump is provided on the outer peripheral surface of the pump. Opening the inspection lid 116 is used not only to inspect the inside but also to remove foreign substances such as gravel clogged inside the pump.
[0023]
A drive motor 120 is incorporated on the back side of the pump 110 on a line concentric with the suction port 114. The outer diameter of the drive motor 120 is the same as the outer diameter of the pump 110 but slightly smaller. The drive motor 120 is operated by inverter control, and is capable of freely increasing or decreasing the capacity of the pump 110 to adjust the pumping capacity and pumping distance of the muddy water. This allows the same tandem pump device to be efficiently used for propulsion over relatively short to long distances.
In use, the discharge port 112 of the pump 110 (A) that is upstream and the suction port 114 of the pump 110 (B) that is downstream are connected by a connection pipe 132. An extension pipe 130 extending further downstream is connected to the discharge port 112 of the pump 110 (B) on the downstream side.
[0024]
An extension pipe 130 connected to the discharge port 112 of the downstream pump 110 (B) is connected to the downstream side of the muddy water discharge pipe 30, and the suction port 114 of the upstream pump 110 (A) is connected to the upstream side of the muddy water discharge pipe 30. Connected to the side.
Therefore, in the tandem pump device 100, muddy water and earth and sand sucked from the suction port 112 of the upstream pump 110 (A) are sent out from the extension pipe 130 connected to the discharge port 112 of the downstream pump 110 (B), Pump muddy water and earth and sand.
The pump capacity or pressure of the cascade pump device 100 is a combination of the two pumps 110, and has a pressure or capacity about twice or more as compared with the case where only one pump 110 is used.
[0025]
The base 140 on which the pair of pumps 110 and the drive motor 120 are installed includes a columnar support bar 142 arranged in parallel with a space left and right. Both ends of the support bar 142 are rounded. Between the left and right support bars 142, a section steel material such as a channel steel is laid over to form a thick frame structure as a whole. The pump 110 and the drive motor 120 are mounted on the upper part of the base 140.
[Detailed structure of pump]
As shown in FIG. 3, the pump 110 has an impeller 118 attached to a rotating shaft 117 rotated by a drive motor 120. By rotating the impeller 118 in the internal space of the pump 110, muddy water sucked from the suction port 114 on the center side is passed through the impeller 118 and sent out to the discharge port 112 on the outer peripheral side. The inspection lid 116 is provided at a position corresponding to the outer periphery of the impeller 118. When the inspection lid 116 is opened, gravel or the like caught on the impeller 118 can be easily taken out.
[0026]
The internal space of the pump 110 has a wide flow path so that relatively large gravel can pass through. In addition, it has a smooth inner surface shape so that it will not be damaged when gravels collide. Specifically, the outer shape of the cap 119 that covers the tip of the rotating shaft 117 is spherical. The inner wall at a position facing the cap 119 is angled 115 to widen the gap between the inner wall and the cap 119.
[Protective cover]
FIG. 4 shows a state where the protective cover 150 is attached to the tandem pump device 110. When the cascade pump device 110 is used for the muddy water propulsion method, there is a possibility that an operator may be caught by a member of the cascade pump device 110 or may damage the members of the cascade pump device 110 during work such as installation and removal. is there. In particular, when a worker moves inside the buried pipe 20 with the tandem pump device 110 installed inside the narrow buried pipe 20, there is a high possibility that the worker will come into contact with the tandem pump device 110.
[0027]
Therefore, by covering the entire cascade pump device 110 with a protective cover 150 made of a steel plate, a mesh steel plate, or the like, the above-described problem can be solved.
The protection cover 150 is detachably attached to the tandem pump device 110 using bolts and metal fittings. The protective cover 150 covers almost the entirety of the tandem pump device 110, but the end of the extension pipe 130 serving as a discharge port and the end of the suction port 114 on the upstream side are exposed outside the protective cover 150. . The base 140 is also exposed below the protective cover 150.
[0028]
As shown in FIG. 4B, when the tandem pump device 110 with the protective cover 150 is installed inside the buried pipe 20, the left and right support bars 142, 142 of the base 140 are attached to the inner surface of the buried pipe 20. It is supported in contact. If the support bars 142 are slid along the inner surface of the buried pipe 20, it is easy to move the tandem pump device 110 inside the buried pipe 20. In particular, since both ends of the support bars 142 are rounded, they can be prevented from being caught when sliding along the inner surface of the buried pipe 20.
Hanging hooks 152 are attached to the upper portion of the protective cover 150 at a plurality of positions. If the hanging hooks 152 are lifted by a crane device or the like, the entire tandem pump device 110 can be easily carried together with the protective cover 150.
[0029]
With the protective cover 150 attached, the overall length of the cascade pump device 110 is set to be substantially the same as or slightly shorter than the overall length of the buried pipe 20 to be installed. Specifically, a tandem pump device 110 having a total length of 2772 mm is used for the buried pipe 20 of about 3 m.
[0030]
【The invention's effect】
The muddy water supply / discharge device according to the present invention supplies and / or discharges muddy water using a tandem pump device in which a plurality of pumps are arranged adjacent to each other in front and rear.
As a result, it becomes possible to easily install a pump means having a higher pressure or a pumping ability as compared with a single pump even inside a buried pipe having a small space. The pump capacity of the tandem pump device is a synergistic combination of the capabilities of multiple pumps, but its cross-sectional area is not much different from a single pump, so it is installed inside a narrow buried pipe. Also, it is less likely to interfere with various operations.
[0031]
Therefore, the conventional muddy water supply / discharge method can be applied to the long-distance propulsion method without any problem, which is difficult to supply and discharge muddy water, and is useful for improving the workability of the propulsion method or reducing the construction cost. is there.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a muddy water propulsion method representing an embodiment of the present invention. FIG. 2 is a front view (a) and a side view (b) of a tandem pump device.
FIG. 3 is a sectional view showing a detailed structure of the pump. FIG. 4 is a front view (a) and a side view (b) of the tandem pump device with a cover attached.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Lead conductor 20 Buried pipe 30 Mud drain pipe 40 Mud supply pipe 42 Mud pump 50 Mud treatment unit 60 Propulsion jack 100 Tandem pump unit 110 Pump 112 Discharge port 114 Suction port 120 Drive motor 130 Extension pipe 132 Connection pipe 140 Base 142 Support bar 150 Protective cover

Claims (3)

In the propulsion method of excavating the ground with a leading conductor to form a burial hole and propel the leading conductor and a buried pipe connected behind it to the burial hole, mud water is supplied to the excavated surface of the ground with the leading conductor. A device for discharging excavated earth and sand together with muddy water,
Muddy water supply pipe laid from the outside of the burial hole through the inside of the buried pipe to the excavation surface of the leading conductor,
Muddy water discharge pipe laid from the excavated surface of the leading conductor through the inside of the buried pipe to the outside of the buried pipe,
Pump means for pumping muddy water, which is arranged in the middle of the muddy water supply pipe and the muddy water discharge pipe,
At least a pump means arranged in the muddy water discharge pipe has a base arranged inside the buried pipe, a plurality of sets of pumps arranged in front and rear on the base and motors for driving the pumps, and an upstream side Muddy water supply / discharge device which is a tandem pump device having a connection pipe for connecting a discharge port of the pump to a suction port of a downstream pump. The base of the tandem pump device is disposed at an interval in parallel with the axial direction of the buried pipe, a support bar having a cylindrical shape with both ends rounded, and a support bar disposed in the middle of a pair of support bars. The muddy water supply / discharge device according to claim 1 , further comprising a supporting frame member to be connected. The muddy water supply / discharge device according to any one of claims 1 to 2 , wherein a plurality of sets of pumps provided in the tandem pump device have a higher withstand pressure in an upstream pump than in a downstream pump.

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