Open shield machine

Abstract

To provide an open shield machine capable of smoothly expanding and contracting a slide box even on sandy ground with groundwater, suppressing loosening of a side part of a face of the ground in front of the front part, fully exhibiting its function, and stably holding a slope of the face of the ground during construction.SOLUTION: An open shield machine 1 is a shield machine with openings on the front, rear, and top, consisting of left and right side wall panels and a bottom plate of approximately the same length that connects them. A machine body is divided into multiple sections in the longitudinal direction, with a front end of a rear body (tail section) fitting into a rear end of a front body (front section 2), allowing them to bend at a mating joint. The left and right side wall panels at the front end of the front section 2 are formed as slide box storage sections 27 that function as door pockets, and these slide box storage sections 27 are provided with movable divided cutting edges in which slide boxes 9 are stored so that they can be extended and retracted back and forth. The slide box storage section 27 is configured to allow water injection.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an open shield machine used in the open shield construction method for burying concrete culvert boxes for rainwater, sewage, etc. in urban areas, and concrete U-shaped open channels underground in river renovation work. [Background technology]

[0002] As is well known, the open shield tunneling method is a highly rational method that combines the advantages of the open cut method and the shield tunneling method.

[0003] First, we will explain the open shield machine used in the open shield construction method. As described in the patent document below, it is basically a shield machine with openings on the front, back, and top, consisting of left and right side wall panels and a bottom plate that is approximately the same length as these side wall panels and connects them. [Patent Document 1] Patent No. 7025375

[0004] As shown in Figures 12 to 14, the fuselage is divided into multiple parts in the fore-and-aft direction, and the front end of the front fuselage, which serves as the front section 2, is fitted into the front end of the rear fuselage, which serves as the tail section 5, making it possible to bend at the mutual fitting section.

[0005] The front section 2 is where excavation is mainly performed, and has an open front end and top surface. Inside the machine body, folding jacks 11 are arranged on both sides of the rear of the machine, facing rearward, and are arranged in multiple levels, one above the other.

[0006] The tail section 5 is where the concrete box 4 is installed, and inside the machine body, propulsion jacks (shield jacks) 3 are arranged on both sides of the front of the machine body facing rearward, and are arranged in multiple tiers above and below.

[0007] In the figure, 9 is a slide box that acts as a movable dividing cutting edge provided at the front end of the front section 2 to prevent side collapses during excavation. The slide box can be pushed forward from the tip of the shield machine or pulled back into the tip by extending or retracting a slide jack 10 attached inside the slide box.

[0008] The left and right side wall panels at the tip of the front part 2 form a slide box storage section 27 as a door pocket, and the slide box 9 as the movable dividing blade can be taken in and out from there.

[0009] In the figure, 12 is a partition wall that separates the excavation section in front of the open shield machine 1 from the hydraulic equipment storage section, and when the shield machine 1 excavates, it presses and compacts the excavated soil in the front section, suppressing the front face rock mass and stabilizing the face rock mass slope formed in front of the face. Therefore, it is useful when working on ground with high groundwater levels or soft ground.

[0010] In the figure, 13 is a press bar (pressure bar). It is installed between the shield jack 3 and the rear concrete box 4, and when the open shield machine 1 is advanced, the shield jack 3 extends and presses against the press bar 13, so that the thrust is evenly transmitted to the rear concrete box 4.

[0011] The bent portion where the front section 2 and tail section 5 fit together is used for correcting direction and gradient, and for constructing curves. The bent jack 11 installed at the bent portion allows the front section 2 of the shield machine 1 to be bent left and right relative to the tail section 5, or to be directed up and down.

[0012] As shown in Figure 20, the open shield construction method using such an open shield machine 1 involves assembling and installing the open shield machine 1 in the starting tunnel 7, extending the thrust jacks 3 of the shield machine 1, using the reaction force from the reaction wall 8 in the starting tunnel to move the shield machine 1 forward, and suspending the first concrete box 4 that forms the underground structure from above and setting it behind the retracted thrust jacks 3 with the tail section 5 of the shield machine 1.

[0013] The departure tunnel 7 is retained by retaining sheet piles 19, and in order to launch the open shield machine 1, the retaining sheet piles 19 in front of the departure direction of the retaining wall are removed and cut into a mirror image, but if necessary, ground improvement work can be done in front of the departure tunnel 7 by injecting chemicals, etc.

[0014] Next, an excavator 6 such as a shovel is used to form an excavation slope forward from within the front section 2 of the open shield machine 1, while excavating and discharging earth and sand from the front or top surface.

[0015] The installation of the concrete box 4 involves laying the concrete box 4 inside the tail portion of the shield machine 1, and typically uses a lifting machine 14 such as a rough terrain crane or a crawler crane.

[0016] After the concrete box 4 is installed in the tail section, a plastic backfill injection material 15 is initially injected into the gap between the inner surface of the tail section and the outer surface of the concrete box 4 from inside the concrete box 4 through grout holes previously installed in the concrete box 4 (not shown).

[0017] The open shield machine 1 is advanced by using the reaction force of the laid concrete box 4 by means of a driving jack 3 disposed inside the shield machine.

[0018] Then, a tail void (corresponding to the thickness of the tail bottom plate and side plate) that occurs underground as the shield machine 1 advances is filled with plastic backfill injection material 15 again through the grout hole in the concrete box 4 as a secondary injection. As described above, the concrete boxes 4 are installed one after another to construct underground culverts for rainwater, sewage, etc. Summary of the Invention [Problem to be solved by the invention]

[0019] When the open shield machine 1 is excavating, the excavator 6 located in front of the open shield machine 1 usually excavates the ground at the face while forming a slope toward the front. At this time, the slide box 9 is extended forward to hold down the ground on both sides of the excavated slope formed from the tip of the front section 2 toward the front so that the ground on both sides of the slope does not collapse.

[0020] The extension length, number of slide boxes 9 to be used, and location of use are selected according to the type of soil at the tunnel face, ground composition, hardness or softness, presence or absence of groundwater, groundwater level, etc., to maintain the stability of the tunnel face. Therefore, the open shield machine 1 can be safely excavated and advanced.

[0021] The left and right side wall panels at the tip of the front part 2 serve as a slide box storage section 27 for storing the slide box 9, and a small gap 28 is provided between the storage section and the slide box to allow the slide box to be inserted and removed smoothly.

[0022] However, when construction is carried out in ground conditions such as sandy ground with a high groundwater level or sandy ground with small grain size and groundwater, the gap 28 may become clogged with sand, especially if the sand grain size is small, which may cause problems in moving the slide box 9 in and out.

[0023] If the grain size of the sand is smaller than the gap 28, the sand will gradually flow into and accumulate in the storage section 27 along with groundwater, making it more difficult for the slide box 9 to expand and contract.

[0024] In particular, when the excavation depth is deep and the groundwater level is high, the groundwater pressure is also high, making the above condition more severe, and in some cases the slide box 9 may become unable to expand or contract, and may no longer be able to perform its function of preventing the side ground from loosening, and the slide box 9 may have to be replaced.

[0025] Therefore, in order to replace the slide box, it is necessary to prevent the area around the slide box from being affected by groundwater by using steel sheet piles or ground improvement work to retain the soil.

[0026] Therefore, the excavation of the open shield machine must be stopped in order to carry out these operations, and the associated costs are incurred, making it uneconomical.

[0027] The object of the present invention is to eliminate the above-mentioned conventional disadvantages and to provide an open shield machine with open front, rear and top, consisting of left and right side wall panels and a bottom plate of approximately the same length connecting the side wall panels, the body of which is divided into multiple sections in the front-to-back direction, the rear end of the front body of the front body acting as the front section being fitted into the front end of the rear body of the rear body acting as the tail section so that they can be bent at the mating joints, the left and right side wall panels of the front end of the front section being formed as slide box storage sections acting as door pockets, and the slide boxes are stored in these slide box storage sections so that they can be extended and retracted back and forth, and the open shield machine is equipped with movable divided cutting edges that store slide boxes so that they can be extended and retracted back and forth, because the slide boxes can be smoothly extended and retracted even in sandy ground with groundwater, thereby suppressing loosening of the side of the face ground in front of the front section and fully demonstrating its function, and which can stably maintain the slope of the face ground during construction. [Means for solving the problem]

[0028] In order to achieve the above-mentioned object, the present invention of claim 1 is an open shield machine with open front, rear and top, consisting of left and right side wall panels and a bottom plate that is approximately the same length as these side wall panels and connects them, the body of the machine is divided into multiple parts in the front-to-back direction, the rear end of the front body as the front part is fitted into the front end of the rear body as the tail part, and they can be bent at the mutual fitting parts, the left and right side wall panels at the front end of the front part are formed as slide box storage parts as door pockets, and this slide box storage part is equipped with a movable divided cutting edge that stores a slide box so that it can be extended and retracted back and forth, and the gist is that water can be poured into the slide box storage part.

[0029] According to the present invention described in claim 1, when construction is carried out under ground conditions such as sandy ground with groundwater, even if sand flows in through the gap between the slide box and the slide box storage section along with the flowing groundwater and accumulates in the box storage section, this sand can be discharged by water injected into the slide box storage section.

[0030] The present invention as set forth in claim 2 is characterized in that a lid member that opens and closes toward the front is provided on the tip end side of the bottom or side of each slide box.

[0031] According to the present invention described in claim 2, a lid that opens and closes toward the front is hinged to the tip of the underside or side of each slide box, so that the poured water can be stored until it reaches a certain water pressure, and the lid can be opened using the water pressure, allowing the accumulated sand to be discharged all at once.

[0032] The present invention as described in claim 3 is characterized in that water is poured by installing an underwater pump in a water tank placed on the rear of the front section, connecting the underwater pump to each of the slide box storage sections located deeper than the groundwater level with pipes, and supplying water by the water pressure caused by the head difference between the water tank and each of the slide box positions located deeper than the groundwater level, or by operating the underwater pump.

[0033] According to the present invention as set forth in claim 3, the difference in hydraulic head between the water tank placed on the rear of the front part of the open shield machine and the water pressure in the slide box located below the groundwater level causes water stored in the water tank to be sent into the box storage section through the connected piping. This water pressure then allows the sand remaining in the box storage section to be discharged.

[0034] Furthermore, if the water pressure at the depth of the slide box, which is deeper than the groundwater level, is greater than the head pressure due to the difference in elevation with the water tank, sand will continue to remain in the slide box storage section at that depth.However, by operating the underwater pump installed in the water tank, the water pressure will force water into the box storage section, allowing the sand that has remained in the box storage section to be discharged from the gaps.

[0035] The present invention as described in claim 4 is characterized in that water is injected by installing an underwater pump in a water tank placed on the rear of the front part of the open shield machine, connecting the underwater pump to each of the slide box storage sections with piping, installing valves near each of the box storage sections on the piping connected to each of the box storage sections, and supplying water by opening and closing the valves.

[0036] According to the present invention as set forth in claim 4, a valve is installed on the box storage side of the piping connected to each slide box storage section, so that by selecting the valve of the box storage section where sand has accumulated and setting it to the "open" state, sand can be discharged only from the box storage section where sand has accumulated.

[0037] Furthermore, by adjusting the open / close state of the valve on the pipe connected to the box storage section where sand is accumulating, the amount of water supplied to the box storage section can be adjusted, so that the accumulating sand can be discharged from the gap smoothly and in a short time. [Effects of the Invention]

[0038] As described above, the open shield machine of the present invention can easily and quickly discharge the sand even in sandy ground with groundwater and even if sand flows into and stagnates inside the slide box storage section that houses the slide box, allowing the slide box to be smoothly extended and retracted, so that the slide box can reliably hold down the side ground in front of the front section.

[0039] This eliminates the need to replace slide boxes, making it possible to safely stabilize the face and excavate the open shield machine. [Brief explanation of the drawings]

[0040] [Figure 1] 1 is a longitudinal sectional side view showing an embodiment of an open shield machine of the present invention. [Figure 2] 1 is a cross-sectional plan view showing an embodiment of an open shield machine of the present invention. [Figure 3] 1 is an enlarged vertical cross-sectional plan view of a slide box portion before extension, showing one embodiment of the open shield machine of the present invention. FIG. [Figure 4] 1 is a longitudinal sectional side view showing one embodiment of the open shield machine of the present invention when the slide box is extended. FIG. [Figure 5] 1 is a cross-sectional plan view showing one embodiment of the open shield machine of the present invention when the slide box is extended. FIG. [Figure 6] 1 is an enlarged cross-sectional plan view of a slide box portion when extended, showing one embodiment of the open shield machine of the present invention. FIG. [Figure 7] FIG. 10 is a longitudinal sectional side view of a slide box with a hinged lid. [Figure 8] FIG. 8 is a view taken along the line AA in FIG. 7. [Figure 9] FIG. 10 is a longitudinal sectional side view of the slide box with the lid hinged when extended. [Figure 10] FIG. 10 is a view taken along the line BB in FIG. 9. [Figure 11] FIG. 1 is a cross-sectional plan view of a slide box with a hinged lid. [Figure 12] FIG. 1 is a cross-sectional plan view of a conventional open shield machine. [Figure 13] FIG. 1 is a longitudinal sectional side view of a conventional open shield machine. [Figure 14] FIG. 1 is a front view of a conventional open shield machine. [Figure 15] FIG. 13 is an enlarged view of part A in FIG. [Figure 16] FIG. 10 is a plan view of a slide box portion of a conventional open shield machine. [Figure 17] FIG. 10 is a cross-sectional plan view of a slide box portion of a conventional open shield machine. [Figure 18] FIG. 18 is a view taken along the line AA in FIG. [Figure 19] FIG. 18 is a view taken along the line BB in FIG. [Figure 20] This is an outline diagram of the open shield construction method. [Figure 21] FIG. 1 is a perspective view of an open shield machine. [Figure 22]This is a cross-sectional plan view showing the inflow of groundwater, etc. when the slide box is extended. [Figure 23] This is a vertical cross-sectional side view showing the inflow of groundwater, etc. when the slide box is extended. [Figure 24] This is an enlarged cross-sectional plan view showing the inflow of groundwater, etc. when the slide box is extended. DETAILED DESCRIPTION OF THE INVENTION

[0041] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 is a longitudinal sectional side view showing an embodiment of the open shield machine of the present invention, and Fig. 2 is a cross-sectional plan view of the same, in which the same reference numerals are used to designate the same components as those in Figs. 12 to 14 showing the conventional example.

[0042] The basic shape of the open shield machine 1 is the same as that of the conventional example, with the machine body divided into multiple sections in the longitudinal direction, with the front end of the tail section 5 fitting into the rear end of the front section 2, and the fitting section, the center folding section 16, being bendable. 11 is a center folding jack, 12 is a bulkhead, and 13 is a press bar (press angle).

[0043] In the tail section 5, propulsion jacks (shield jacks) 3 are arranged on the left and right sides of the front of the aircraft facing rearward, and are also arranged in multiple stages above and below.

[0044] In the drawing, 9 is a slide box, which is a movable dividing cutting edge provided at the front end of the front part 2 to prevent the ground from collapsing on the sides during excavation, and the left and right side wall panels at the front end of the front part 2 form a slide box storage section 27 that functions as a door pocket. 10 is a slide jack that extends and retracts the slide box 9 back and forth.

[0045] As described above, the open shield construction method using such an open shield machine 1 involves appropriately repeating the following steps to bury concrete boxes in a vertical row one after another: excavating and discharging the top sand in front of or in front of the top opening of the open shield machine 1; extending the propulsion jacks 3 and using the concrete box 4 as a reaction force to move the open shield machine 1 forward; and suspending and lowering a new concrete box 4 from above behind the propulsion jacks 3 that have been retracted within the tail section 2 of the shield machine 1 and setting it there.

[0046] The open shield machine 1 of the present invention is designed so that water can be poured into the slide box storage section 27.

[0047] A water tank 21 equipped with an underwater pump 22 is placed on the rear of the front part 2 of the open shield machine 1, and the underwater pump 22 is connected to a slide box storage part 27 deeper than the groundwater level by a pipe 23 so that water can be supplied into the box storage part 27.

[0048] The submersible pump 22 is connected to each of the slide box storage sections 27 located below the groundwater level by piping 23, and water is supplied by the water pressure due to the difference in head between the water tank 21 and the slide box storage section 27 located below the groundwater level, or by operating the submersible pump 22.

[0049] The piping 23 is a main pipe extending from the water tank 21 and branches appropriately to connect to each slide box storage section 27.

[0050] By filling the box storage section 27 with water through the piping 23 in this way, even when the submersible pump 22 is not operating, if there is a sufficient head difference between the water tank 21 and the depth of the box storage section 27, which is deeper than the groundwater level, the water in the water tank 21 will be transported from the water tank 21 to the box storage section 27 through the piping 23 using the siphon principle.

[0051] Therefore, even if sand enters and accumulates in the box storage section 27 together with groundwater through the gap 28 between the slide box 9 and the box storage section 27 at a depth below the groundwater level, the water in the water tank 21 is supplied, so the accumulated sand can be discharged from the gap 28.

[0052] In addition, if the head difference between the slide box storage section 27, which is deeper than the groundwater level, and the water in the water tank 21 is small and the sand accumulated in the box storage section 27 cannot be discharged due to the head difference and siphon principle as described above, the underwater pump 22 can be operated so that the water pressure can be used to discharge the accumulated sand from the gap 28.

[0053] As a second embodiment of the present invention, a valve 24 is installed on the box storage section 27 side of a pipe 23 connected to each slide box storage section 27.

[0054] In this way, by installing a valve 24 on the box storage section 27 side of the piping 23 connected to each slide box storage section 27, the valve 24 of the box storage section 27 where sand has accumulated can be selected and set to the "open" state, and the other valves 24 can be set to the "closed" state, so that the sand from only the box storage section 27 where sand has accumulated can be discharged from the gap 28 of the box storage section 27.

[0055] Furthermore, by adjusting the open / close state of the valve 24 of the pipe 23 connected to the box storage section 27 where sand is accumulated, the amount of water supplied to the box storage section 27 can be adjusted, so that the accumulated sand can be smoothly and quickly discharged from the gap 28. The valve 24 may be any of a globe valve, a ball valve, and a butterfly valve.

[0056] Also, although not shown in the figure, in ground conditions where the sand particles are small, the slide box 9 located above the groundwater level needs to be frequently extended and retracted while the open shield machine 1 is excavating.If sand becomes clogged in the gap 28 of the box storage section 27 and the slide box 9 can no longer be extended or retracted, an additional pipe 23 is connected to the slide box storage section 27, and water is supplied from the submersible pump 22 to clean the clogged gap 28 and discharge the sand.

[0057] In a third embodiment of the present invention, a lid member 26 that opens and closes forward is attached by a hinge to the bottom or side of each slide box at the tip end.

[0058] The lid material 26 is hinged to the tip end of the slide box 9 so that it opens and closes toward the front, so that the lid material 26 opens toward the front when the slide box 9 is extended, and closes when the slide box 9 is stored in the slide box storage section 27.

[0059] When the excavation depth of the open shield machine 1 is deep, the groundwater pressure is high, so it is expected that a large amount of sand will flow into and remain in the slide box storage section 27.

[0060] In this case, there is a risk that the sand may not be able to be completely discharged from the gap 28 of the box storage section 27, which may cause problems with the extension and contraction of the slide box 9, but since the lid material 26 opens forward due to the water pressure from the water tank 21, in addition to being discharged from the gap 28, a large amount of accumulated sand can be smoothly discharged from there.

[0061] In addition, the slide box 9 located at the lowest level is installed on the side of the slide box 9 because it is expected that if the lid material 26 is installed on the side, it may not be able to open due to the ground below or soil and sand accumulated in front of the partition wall 12. [Explanation of symbols]

[0062] 1...Open shield machine 2...Front part 3...Propulsion jack (shield jack) 4...Concrete box body 5...Tail section 6...Excavator 7...Starting tunnel 8...Reaction wall 9...Slide box 10...Slide jack 11...Bending jack 12...Bulkhead 13...Press bar (press angle) 14... Lifting machine 15... Backfill injection material 16...Bent part 17...Backfill soil 18...Groundwater level 19...Earthen sheet pile 20...Groundwater and sediment inflow 21...Water tank 22...Submersible pump 23...Piping 24...Valve 25...Water supply 26... Lid material 27... Slide box storage section 28...Gap

Claims

1. A shield machine with open front, rear and top, consisting of left and right side wall panels and a bottom plate connecting them of approximately the same length, the body of which is divided into multiple parts in the front-to-back direction, the rear end of the front body serving as the front section being fitted into the front end of the rear body serving as the tail section so that they can be bent at the mutual fitting section, the left and right side wall panels at the front end of the front section being formed as slide box storage sections as door pockets, and this open shield machine is equipped with a movable dividing cutting edge that stores a slide box in this slide box storage section so that it can be extended and retracted back and forth, characterized in that water can be poured into the slide box storage section.

2. 2. The open shield machine according to claim 1, wherein a lid member that opens and closes toward the front is provided on the bottom or side of each slide box at the tip end.

3. An open shield machine as described in claim 1 or claim 2, in which water is injected by installing an underwater pump in a water tank placed on the rear of the front section, connecting the underwater pump to each of the slide box storage sections deeper than the groundwater level with pipes, and supplying water by the water pressure of the head difference between the water tank and each of the slide box positions deeper than the groundwater level, or by operating the underwater pump.

4. An open shield machine according to claim 1 or claim 2, wherein water is supplied by installing an underwater pump in a water tank placed on the rear of the front part of the open shield machine, connecting the underwater pump to each of the slide box storage sections with piping, installing valves near each of the box storage sections on the piping connected to each of the box storage sections, and opening and closing the valves.

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