JPH0358438B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for transferring earth and sand produced by excavating a ground during tunnel construction using the shield method, in which earth and sand is discharged to the ground using a pressure pump.

``Conventional technology'' In tunnel excavation work using the shield method, a shield excavator is operated to excavate the ground under mud, and when the excavation has progressed a predetermined distance, the excavation is stopped and segments are assembled, and this process is repeated in sequence. Digging a tunnel. Then, in parallel with the excavation of the ground by the shield excavator, a pressure pump is operated intermittently, and the pressure pump discharges the earth and sand discharged from the shield excavator to the ground through a transport pipe.

``Problems to be Solved by the Invention'' However, conventionally, when the above-mentioned pressure pump is stopped, gravel in the earth and sand is removed from the taper of the transport pipe, where the cross section of the flow path gradually decreases as it goes downstream. Depending on the specific gravity, it may settle and accumulate in the bends at the lower end of the transport pipe, especially when excavating a rock with a lot of gravel. The gravel increases the starting load on the pressure pump, and in some cases, there is a problem in that the pressure pump cannot be restarted.

The present invention was made in view of the above circumstances, and
The purpose of the present invention is to provide a method for transferring earth and sand in tunnel construction, which reduces the starting load of a pressure pump and facilitates the transfer of earth and sand.

``Means for Solving the Problems'' In order to achieve the above object, the transfer method of the present invention provides, before starting the pressure pump, a transfer pipe that The muddying agent is injected from below into a non-straight pipe section such as a tapered section where the cross section of the flow path gradually decreases.

"Operation" In the transfer method of the present invention, accumulation in non-straight pipe parts such as the bent parts and tapered parts of the transport pipe,
The gravel that has settled and accumulated is suspended by the muddying agent injected from below into the non-straight pipe section, thereby reducing the starting load on the pressure pump.

"Example" An example of the method of the present invention will be described below.

First, an apparatus for carrying out the method of the present invention will be described with reference to FIGS. 1A to 2C and FIG. 2, together with a shield tunneling machine. Reference numeral 1 in the figures indicates the shield tunneling machine. At the rear of the shield excavator 1 are a mixer device 2, a pressure pump 3, a hydraulic unit for the shield excavator 1, ancillary devices 4 such as a control panel, and mud adding equipment 5.
etc. are connected sequentially.

The shield excavator 1 excavates the ground at the face using a cutter 6 on the front, discharges the earth and sand generated by this excavation backward through a screw conveyor 7, and segments the excavated part by an erector 8. S is assembled in sequence.

In addition, the mixer device 2 is provided with a mixing tank 11 that is open at the top and connected to a discharge port 11a at the rear end on a bogie 10 that is made to run on a track rail 9. , a spiral blade member 12a and a slightly inclined paddle-shaped blade member 12
A pair of left and right mixing blades 12, 12 (both are overlapped in FIG. , the pair of left and right mixing blades 1
The structure is such that a drive device 14 is mounted to rotate the components 2 and 12 via a transmission mechanism 13. and,
The rear end of a belt conveyor 15 whose front end faces the discharge port of the screw conveyor 7 of the shield excavator 1 is attached to the upper part of the mixing tank 11 so as to be movable back and forth. Ya1
5, the earth and sand discharged through the screw conveyor 7 of the shield excavator 1 is sent into the mixing tank 11. In addition, the excavation has been completed,
A dilution water pipe 17 in which a plurality of take-out valves 16 are installed at a predetermined pitch in the longitudinal direction is provided along the longitudinal direction of the tunnel section in which the segments S have been installed, The dilution water can be led to the mixing tank 11 by a hose from a required take-out valve 16 of the dilution water piping 17.

Further, the pressure pump 3 is a slurry pump installed on the upper part of a truck 19 connected to the truck 10 of the mixer device 2 via a connecting member 18,
Hydraulic unit 22 on a truck 21 equipped with a receiving hopper 20 at the front and connected to the rear of the truck 19
It is driven by The receiving hopper 20 of the pressure pump 3 is provided with the rear end of a belt conveyor 23 whose front end faces the discharge port 11a of the mixing tank 11 of the mixer device 2. A wheel feed pipe 24 is connected to the discharge port. This transport pipe 2
Reference numeral 4 denotes a riser pipe 24a whose one end is connected to the discharge port, rises upward at the front part of the receiving hopper 20, and whose other end is bent horizontally toward the rear at a predetermined height; A tapered pipe 24b whose front end is connected to the other end of 24a and whose flow path cross section gradually decreases toward the downstream (backward)
and an upper horizontal pipe 24c whose front end is connected to the rear end of the tapered pipe 24b and supported by a bracket 25 mounted on each of the carts 19 and 21,
The front end is connected to the rear end of this upper horizontal pipe 24c via the upper curved pipe 24d, and the down pipe 24e slopes diagonally downward as it goes downstream, and the front end is connected to the rear end of this down pipe 24e. A lower horizontal pipe 24g connected via a lower bent pipe 24f and provided along the track rail 9, and an expansion joint pipe device 26 connected to the rear end of the horizontal pipe 24g via an inclined pipe 24h. The expansion joint pipe device 26 consists of a pipe (not shown) to which the front end is connected and the rear end is connected to the ground.

Furthermore, the mud adding equipment 5 is provided further behind the attached equipment 4 such as the hydraulic unit and the control panel of the shield excavator 1 which is installed behind the pressure pump 3, and is used to add bentonite, viscosity, etc. This has been conventionally provided for adding mud by injecting a slurry-like muddying agent produced by adding water to the inside of the screw conveyor 7, etc. of the shield excavation machine 1. This mud adding equipment 5 is constructed by installing a single mud adding unit on a pair of front and rear trucks 28, 28 connected to a truck 27 of the attached device 4 (this truck 27 is connected to a truck 21 of the pressure pump 3). Sludge tank 2
9 and two muddying agent pumps 30, 30 (one of these two pumps is a standby pump) are installed, and the discharge pipe 30a of each muddying agent pump 30 is connected to the pressure pump 3. It extends along the equipment in front of the shield tunneling machine 1, and its terminal end is connected to a muddying agent transfer pipe 31 that is connected to a muddying agent injection pipe (not shown) of the shield tunneling machine 1.

Further, the muddy agent transfer pipes 31 are collected into one pipe near each muddying agent pump 30, and then branched near the lower bent pipe 24f of the transport pipe 24, and the branched pipe 31a is , is connected to the lower bent pipe 24f through the first electromagnetic switching valve 31 and the check valve 33 in an obliquely upward direction from below toward the rear, and is connected to the lower bent pipe 24f in the vicinity of the tapered pipe 24b of the transport pipe 24. is also branched, and the branch pipe 3
1b is connected to the tapered pipe 24b through a second electromagnetic switching valve 34 and a check valve 35 so as to be inclined obliquely upward from below toward the rear, while the branch pipe 3
A third electromagnetic switching valve 36 is provided downstream (front side) of the branch portion 1b. Each of the electromagnetic switching valves 32, 34, 36 is controlled by a control device 37.
The opening and closing of the control device 37 is controlled by the control device 37, and the control device 3
7 is adapted to start the pressure pump 3 at a predetermined time lag from the opening/closing operation time of each electromagnetic switching valve 32, 34, 36.

The earth and sand produced when the ground is excavated by the shield excavator 1 is fed into the mixer device 2 by the belt conveyor 15, and the dilution water pipe 17
After being diluted to an appropriate concentration with dilution water from the pump and being mixed by the mixing blade 12, it is fed into the receiving hopper 20 of the pressure pump 3 by the belt conveyor 23. Then, it is discharged to the earth through the transport pipe 24 by the pressure pump 3.

After the earth and sand are pumped by the pressure pump 3, earth and sand accumulate inside the transport pipe 24, and gravel in this earth and sand is transferred to the tapered pipe 24b (tapered part) and the lower bent pipe 24f (bent part) of the transport pipe 24. However, in the present invention, before starting the pressure pump 3, the muddying agent is deposited on the tapered pipe 24b and the lower bent pipe 24.
The starting load on the pressure pump 3 is reduced by injecting it into the inside of the pump 3 from below.

That is, immediately before starting the pressure pump 3, the control device 37 controls the first and second electromagnetic switching valves 32,
At the same time as switching the third electromagnetic switching valve 34 to the open state, the third electromagnetic switching valve 36 is switched to the closed state. During excavation, the muddying agent sent from the muddying agent pump 30 to the shield excavator 1 through the muddying agent transfer pipe 31 is transferred to the inside of the tapered pipe 24b and the lower bent pipe 24f through each branch pipe 31a, 31b. Inject diagonally from below,
The debris accumulated inside the tapered pipe 24b and the lower bent pipe 24f is suspended. Next, in this state, the pressure pump 3 is started by the control device 37 when several seconds have elapsed from the time when the electromagnetic switching valves 32, 34, and 36 were operated. Then, since the gravel is floating, there is almost no resistance due to it, and the starting load on the pressure pump 3 is significantly reduced. Therefore, it is no longer impossible to restart the pressure pump 3 as in the conventional case, and work efficiency is greatly improved.

Moreover, since most of the muddying equipment 5 for the shield tunneling machine 1 is used to inject the muddying agent into the transport pipe 24, it is extremely easy to carry out, and the equipment cost can be reduced. Furthermore, the control device 37 controls the opening and closing of the electromagnetic switching valves 32, 34, and 36 and the pressure pump 3.
Since the timing of activation of the slurry is controlled and the muddying agent is automatically injected into the transport pipe 24, the workability is extremely good.

In addition, in the above, the mixer device 2 has a simple structure and has good mixing efficiency and transfer efficiency because it is equipped with mixing blades 12, 12 having spiral and paddle-shaped blade members 12a, 12b. ,Also,
Since the belt conveyor 15 is movably provided in the mixing tank 11, it has advantages such as being able to move the shield excavator 1 forward even when the mixer device 2 is stopped.

Further, in the above description, the slurry agent is injected into the tapered pipe 24b and the lower bent pipe 24f of the transport pipe 24, but the location and number of the parts to be injected may change depending on the shape, structure, etc. of the transport pipe 24. Needless to say.

"Effects of the Invention" As explained above, the present invention provides a bending section at the lower end of the transport pipe before starting the pressure pump, a tapered section where the cross section of the flow path gradually decreases as it goes downstream, etc. Slurry-like muddying agent is injected from below into the non-straight pipe section, and the pressure pump is started while pushing up the lumps existing in the non-straight pipe section. When excavating a pipe, even if gravel remains in a non-straight pipe, the pump starts pumping once it is lifted from the bottom of the pipe, which greatly reduces the starting load on the pump. ,
The pressure pump can be restarted easily, and the earth and sand can be transferred smoothly.

[Brief explanation of drawings]

The drawings are for explaining the method of the invention,
Figures 1 a to c are cross-sectional views showing the tunnel being excavated using the shield method (Figure 1 a is followed by b, and b is followed by c), and Figure 2 is a cross-sectional view showing the state in which a tunnel is excavated using the shield method. 1 is a schematic diagram showing the injection method of 1... Shield tunneling machine, 2... Mixer device, 3
. . . Pressure pump, 5 . Switching valve, 37...control device.

Claims (1)

[Claims] 1. In a method of transporting earth and sand in tunnel construction in which the earth and sand produced by excavating the ground under mud with a shield excavator are discharged to the ground through a transport pipe using a pressure pump, the above-mentioned pressure pump is used. Before starting up, a slurry-like muddying agent is injected from below into the non-straight pipe parts, such as the curved part at the lower end of the transport pipe and the tapered part where the channel cross section gradually decreases as it goes downstream. A method for transferring earth and sand in tunnel construction, characterized in that the pressure pump is started while pushing up the lumps existing in the non-straight pipe section.