Open shield machine and concrete box construction method using the same

Abstract

To provide an open shield machine that can operate even in ground with groundwater and that can be fully constructed using a box body as a reaction force even when soil covering is large and a drilling depth is deep relative to the height of the box body to be laid, and a method for laying a concrete box body using this machine.SOLUTION: A concrete box body 4 is laid using an open shield machine 1 consisting of an upper propulsion structure shield machine 36 and a lower propulsion structure shield machine 35 having different propulsion structures connected vertically.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an open shield machine and a method for laying a concrete box using the same. [Background technology]

[0002] The open shield method is a highly rational method that combines the advantages of the open cut method and the shield method. Figure 24 shows an outline of the method.

[0003] In the figure, reference numeral 1 denotes an open shield machine, which is made up of left and right side wall panels and a bottom panel connected to these side wall panels, and has openings on the front, back and top.

[0004] The open shield machine 1 has a cutting edge at its tip, and propulsion jacks 3 are arranged vertically facing rearward at the center or near the rear end of the side wall plate.

[0005] In addition, the open shield machine 1 has a body divided in the front-rear direction into a front section 18 and a tail section 19, and the front end of the tail section 19 is fitted into the rear end of the front section 18 to form a center-bending section 34 at the mutual fitting section, making it bendable. A center-bending jack 21 is provided at this center-bending section.

[0006] The front section 18 serves mainly as the excavation section, and the tail section 19 has the propulsion jack 3 arranged therein and serves as the tail section 20 for suspending and installing the concrete box.

[0007] In the figure, reference numeral 16 denotes a movable split cutting edge provided at the front end of the front section 18, and reference numeral 24 denotes a rear retaining plate used when the box body 4 comes out of the tail section 19 as the open shield machine 1 excavates, and the upper part of the box body 4 is backfilled inside this plate.

[0008] The outline of the open shield construction method is as follows: first, the open shield machine 1 is assembled in a designated position inside the starting shaft 8. After assembly, the push jack 3 of the open shield machine 1 is extended to use a reaction force against the reaction wall 9 inside the starting shaft to move the open shield machine 1 forward, and the first concrete box 4 that forms the underground structure is suspended from above and set behind the retracted push jack 3 inside the tail section 20 of the open shield machine 1.

[0009] The concrete boxes 4 that are successively laid inside the starting shaft 8 are boxes that are propelled a specified distance after the open shield machine 1 advances forward and exits the starting shaft 8, and are temporarily laid as reaction force transmission materials until the propulsion force of the open shield machine is no longer transmitted to the reaction wall 9 inside the starting shaft 8, at which point they are removed.

[0010] In addition, the starting shaft 8 is composed of a retaining wall (steel sheet pile 30, etc.), and in order to launch the open shield machine 1, a portion of this retaining wall in front of it is cut away, but if necessary, ground improvement work may be carried out in front of the starting shaft 8 by injecting chemicals, etc.

[0011] Next, after cutting a portion of the retaining wall in front of the starting shaft 8, an excavator 6 such as a shovel is used to excavate and remove soil from the top of the ground in front of the open shield machine 1.

[0012] Simultaneously with or after this soil removal process, the propulsion jack 3 is extended to move the open shield machine 1 forward.

[0013] After the open shield machine 1 moves forward the length of one box, the second concrete box 4 is hoisted by a lifting machine 27 into the tail interior 20 of the open shield machine 1 and set in front of the first concrete box 4.

[0014] Thereafter, the same excavation and soil removal process, advancement process, and concrete box 4 setting process are repeated as appropriate, and the concrete boxes 4 are successively left in the ground in a vertical row as the open shield machine 1 advances, and backfilling 5 is applied to the upper surfaces of these concrete boxes 4, and the surface is paved.

[0015] Once the open shield machine 1 has reached the destination tunnel, it is removed and the construction is completed.

[0016] The above-mentioned prior art techniques are generally known to those skilled in the art and do not relate to inventions publicly known in the literature. Summary of the Invention [Problem to be solved by the invention]

[0017] In the open shield method described above, normally, an excavator 6 placed at the front forms a slope by directing the natural ground at the cutting edge 2 of the front part 18 of the open shield machine 1 forward, while excavating and discharging soil, and extends the shield jack 3 attached to the open shield machine, and propels it forward by applying a thrust reaction force to the laid concrete box 4 at the rear. Therefore, construction is possible if the excavator 6 can excavate to a depth that is possible.

[0018] In addition, as the open shield machine 1 advances, gaps that arise between the ground and the periphery of the bottom and both side panels of the laid concrete box 4 are filled with backfill injection material, so there is less loosening of the surrounding ground due to advancement.Furthermore, since the open shield machine 1 has a bottom plate, it has the advantage that construction can be carried out even in ground with groundwater.

[0019] However, when the excavation depth is deep relative to the height of the laid concrete box 4, the resultant force of the resistance of the ground in front of the shield machine 1 is higher than the resultant force of the thrust of the shield jack 3 when the shield machine 1 is advanced, making it difficult to control the pitching, rolling, and yawing when the shield machine 1 is advanced. In addition, the thrust force acting on the laid concrete box 4 that is in contact with the press bar also becomes large, raising concerns about its impact on the box. In particular, the deeper the excavation depth is, and the greater the excavation depth is relative to the height of the laid concrete box 4, the more difficult it becomes to control the advancement of the open shield machine.

[0020] Furthermore, when the excavation depth is deep in loose sandy ground with groundwater, particularly when the excavator 6 excavates ground at the face deeper than the groundwater level, the natural ground slope formed with the cutting edge of the front section 18 facing forward is prone to collapse. Therefore, if the slope gradient is reduced and the slope length is lengthened to prevent the natural ground slope from collapsing, even if the movable split cutting edges attached to both sides of the front machine are extended, the tip of the natural ground slope will exceed the tip of the movable split cutting edges, and the natural ground on both sides of the face cannot be fully controlled, which could cause the ground at the face to collapse.

[0021] The object of the present invention is to provide an open shield machine which eliminates the above-mentioned inconveniences, is capable of being used in ground containing groundwater, and is capable of performing sufficient construction using the box as a reaction force even when the soil covering is large relative to the height of the box to be laid and the excavation depth is deep. It is also an object of the present invention to provide a method of laying a concrete box using the same. [Means for solving the problem]

[0022] In order to achieve the above object, the present invention provides an open shield machine, firstly, The machine is made up of left and right side walls and a bottom plate that is about the same length as the side walls and connects them. The top surface is open, and the machine has a front section for excavation and a tail section for installing the concrete box. Front end of the tail A lower propulsion structure shield machine with propulsion jacks arranged vertically from the left to the right toward the rear and using the propulsion reaction force on the laying box to move forward; and a lower propulsion structure shield machine with openings on the front, rear, top and bottom. In the extension direction The machine is divided into separate blocks at different vertical positions, and each block is connected with a propulsion and traction jack. The frictional resistance between the side panels divided by the block and the ground in contact with them acts as a propulsion reaction force, and each block moves forward in sequence. This machine is called an upper propulsion structure shield machine. As a slide and support structure connecting the lower propulsion structure shield machine and the upper propulsion structure shield machine, upper propulsion structure slide rails are fixedly installed on the inside of the upper ends of both sides of the front and tail parts of the lower propulsion structure shield machine so that the upper propulsion structure shield machine can slide forward, while upper propulsion structure support members are provided from the lower ends of both sides of the front and tail parts of the upper propulsion structure shield machine to contact the upper end of the lower propulsion structure shield equipment and support the upper propulsion structure shield machine, and a pointed protrusion is provided from the upper propulsion structure slide rails toward the outside, and a pointed protrusion is provided toward the inside of the upper propulsion structure support member, with a gap being secured between them. This is the gist.

[0023] Secondly, the divided blocks of the upper-propulsion structure shield machine consist of a front section, a jack section and a tail section; thirdly, a sliding rail is installed on the lower-propulsion structure shield machine, and the upper-propulsion structure shield machine is installed on the sliding rail so that it can move forward; fourthly, the upper-propulsion structure shield machine is wider than the lower-propulsion structure shield machine; fifthly, Lower propulsion structure shield machine and The gist of the upper thrust structure shield machine is that a sliding retaining plate is provided at the front end of the front section to create a movable split blade.

[0024] As a method for laying a concrete box using an open shield machine, first, a method for laying a box using the open shield machine according to claim 1 or claim 2, comprising the steps of excavating a face of the ground at the cutting edge of the upper-pull structure shield machine, and Front section of Jack section, tail section The frictional resistance between the side plate and the ground is used as a reaction force to extend the first thrust and traction jack. Front section advancing said Front section and the above Tail section a step of shortening the first thrust / traction jack and extending the second thrust / traction jack by using frictional resistance between the first thrust / traction jack and the ground as a reaction force, and moving the jack section forward; Front section and the above Jack section a step of shortening the second thrust / traction jack and advancing the tail portion by using frictional resistance between the second thrust / traction jack and the ground as a reaction force; Tail section The gist of the method is to extend the shield jack of the lower-pull structure shield machine while excavating the ground at the cutting edge of the lower-pull structure shield machine and to advance the lower-pull structure shield machine while repeating this process, and after the open shield machine has advanced one box length, the shield jack is retracted and the box is installed inside the tail part of the lower-pull structure shield machine and buried in the ground.

[0025] Secondly, Front sectionThe process of advancing the shield machine comprises the steps of excavating the ground at the cutting edge of the upper-pushing structure shield machine, sequentially extending forward a sliding earth retaining plate which is provided at the front end of the front section to form a movable divided cutting edge, and using the frictional resistance between the sliding earth retaining plate and the ground in contact with it as a reaction force to retract the slide jack and extend the propulsion jack to advance the machine.

[0026] According to the present invention described in claims 1 and 5, the open shield machine is divided into upper and lower thrust structures, and while the upper-pull shield machine is thrust forward on the lower-pull shield machine using frictional resistance between both side plates of the upper-pull shield machine and the ground in contact with them as thrust reaction force, the excavator located in front of the cutting edge excavates the ground at the face while forming a slope facing forward. Then, the lower-pull shield machine advances while similarly excavating the ground at the cutting edge of the lower-pull shield machine.

[0027] Therefore, after excavation so that the face ground slope of the upper-pull structure is located forward of the face ground slope of the lower-pull structure shield machine, the upper-pull structure section stops and the lower-pull structure shield machine continues digging.

[0028] For this reason, compared to the thrust force used when excavating deep with the open shield method, the thrust force required when advancing with a lower-thrust shield machine is reduced by the thrust resistance caused by the face ground of the lower-thrust section and the resistance caused by friction between the side plates of the lower structure and the ground. As a result, the thrust force acting on the construction box is also reduced, reducing the load on the box.

[0029] In addition, when the bottom-pull structure shield machine is advancing, the resultant resistance force of the ground at the cutting edge of the bottom-pull structure shield machine is approximately the same as the resultant thrust force of the shield jacks of the bottom-pull structure shield machine, so even if the excavation depth is deep, it is easier to control the pitching, rolling, and yawing of the bottom-pull structure shield machine when it is advancing compared to the conventional open shield construction method.

[0030] According to the present invention as described in claim 2, the divided blocks of the upper propulsion structure shield machine consist of three sections: a front section, a jack section, and a tail section, so that the necessary function can be obtained with the minimum number of divided blocks.

[0031] According to the present invention as described in claim 3, a sliding rail is installed on the lower propulsion structure shield machine, and the upper propulsion structure shield machine is installed on the sliding rail so that it can be moved forward, making it easy to move the upper propulsion structure shield machine forward.

[0032] According to the present invention as described in claim 4, in the case of conventional open shield construction methods or when the widths of the upper-pull structure shield machine and the lower-pull structure shield machine are the same, when excavating deep and loose sandy ground, when excavating near the bottom plate of the cutting edge of the lower-pull structure shield machine, the ground slope 45 at the face or the side plate behind the cutting edge may collapse, and this may have an effect on the ground surface near the open shield machine.

[0033] By making the width of the upper thrust structure of the open shield machine larger than the width of the lower thrust section, the above-mentioned risk can be eliminated or reduced.

[0034] In addition, in cases where the excavation depth is deep and the ground is loose, such as sandy ground, the cutting edge of the upper-pull structure shield machine is positioned forward of the tip of the movable split cutting edge of the lower-pull structure shield machine, and the face ground slope at the cutting edge of the upper-pull structure shield machine is made large and concave, and both ends of the ground slope near the toe can be held down by the movable split cutting edge of the lower-pull structure shield machine and the ground on either side of it.

[0035] In addition, the gradient of the face slope at the cutting edge of the upper-propulsion structure shield machine can be made small depending on the condition of the face, thereby ensuring sufficient stability of the slope.

[0036] Therefore, even if the face ground slope at the movable split cutting edge of the lower-pull structure shield machine is about to collapse, the shape of the face ground slope at the cutting edge of the upper-pull structure shield machine can be maintained, so the open shield machine can safely excavate and lay boxes while ensuring the stability of the face ground during excavation.

[0037] Furthermore, since the bottom-pull shield machine has a bottom plate, it can withstand groundwater, so construction is possible even in ground with groundwater as long as the groundwater level is lower than the bottom end of the top-pull shield machine.

[0038] According to the present invention as described in claims 5 and 7, if the first divided body has a single cutting edge during advancing in relatively hard ground, the cutting edge resistance will be large, and there is a risk that advancing will be impossible due to the advancing reaction force caused by the frictional resistance between the side plates of each block and the ground, and if the face ground slope cannot be maintained during excavation in loose ground, the surrounding ground will be prone to loosening.

[0039] In response to this Front section By sequentially extending multiple stages of sliding earth retaining plates forward from the top on both sides of the main frame, it is possible to sequentially retain earth on the face slope and side ground, thereby maintaining the stability of the ground at the cutting edge. Effect of the Invention

[0040] As described above, the open shield machine of the present invention and the concrete box construction method using it can be used in ground containing groundwater, and even when the soil covering is large compared to the height of the box to be laid and the excavation depth is deep, construction can be carried out satisfactorily by using the box as a reaction force. [Brief description of the drawings]

[0041] [Figure 1] 1 is a vertical sectional side view showing one embodiment of an open shield machine of the present invention. [Diagram 2] FIG. 1 is a plan view of an upper propulsion structure shield machine showing one embodiment of the open shield machine of the present invention. [Diagram 3]FIG. 1 is a plan view of a lower propulsion structure shield machine showing a first embodiment of the open shield machine of the present invention. [Figure 4] FIG. 3 is a view taken along line AA in FIG. 2. [Diagram 5] FIG. 3 is a view taken along line BB in FIG. 2. [Figure 6] FIG. 2 is an explanatory diagram showing the first to third steps of the first embodiment of the concrete box construction method using the open shield machine of the present invention. [Figure 7] FIG. 2 is an explanatory diagram showing the fourth to sixth steps of the first embodiment of the concrete box construction method using the open shield machine of the present invention. [Figure 8] FIG. 2 is an explanatory diagram showing the seventh to ninth steps of the first embodiment of the concrete box construction method using the open shield machine of the present invention. [Figure 9] FIG. 2 is an explanatory diagram showing the 10th to 12th steps of the first embodiment of the concrete box construction method using the open shield machine of the present invention. [Figure 10] 1 is a longitudinal cross-sectional side view showing the 13th and 14th steps of a first embodiment of a concrete box construction method using an open shield machine of the present invention. FIG. [Figure 11] FIG. 2 is a vertical cross-sectional side view showing a second embodiment of a concrete box construction method using an open shield machine of the present invention. [Figure 12] FIG. 4 is a plan view of an upper propulsion structure shield machine showing a second embodiment of the open shield machine of the present invention. [Figure 13] FIG. 4 is a plan view of a lower propulsion structure shield machine showing a second embodiment of the open shield machine of the present invention. [Figure 14] 13 is a view taken along line AA in FIG. 12. [Figure 15] FIG. 4 is a plan view showing a second embodiment of the open shield machine of the present invention during excavation. [Figure 16] FIG. 11 is a vertical sectional side view showing a third embodiment of the open shield machine of the present invention. [Figure 17] FIG. 4 is a plan view of an upper propulsion structure shield machine showing a third embodiment of the open shield machine of the present invention. [Figure 18] FIG. 4 is a plan view of a lower propulsion structure shield machine showing a third embodiment of the open shield machine of the present invention. [Figure 19] 19 is a view taken along line AA in FIG. 18. [Figure 20] 19 is a view taken along line BB in FIG. 18. [Figure 21] FIG. 2 is an explanatory diagram showing the first to third steps of a second embodiment of a concrete box construction method using an open shield machine of the present invention. [Figure 22] FIG. 2 is an explanatory diagram showing the fourth to sixth steps of the second embodiment of the concrete box construction method using the open shield machine of the present invention. [Figure 23] 1 is a vertical cross-sectional side view showing the seventh step of a second embodiment of a concrete box construction method using an open shield machine of the present invention. FIG. [Figure 24] FIG. 2 is a perspective view showing the construction status of the open shield method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. Fig. 1 is a vertical cross-sectional side view showing one embodiment of the open shield machine of the present invention, Fig. 2 is a plan view of the same upper-propulsion structure shield machine, and Fig. 3 is a plan view of the same lower-propulsion structure shield machine. In the figures, 1 is an open shield machine in which an upper-propulsion structure shield machine 36 and a lower-propulsion structure shield machine 35, which have different propulsion mechanisms, are connected vertically.

[0043] The upper propulsion structure shield machine 36 has openings on the front, rear, top and bottom, and is divided at different positions in the extension direction from the lower propulsion structure shield machine to form split blocks.As an example, this split block consists of a first block, a second block and a third block, each consisting of a front section, a jack section and a tail section from the front, and the front end of the second block is fitted into the rear end of the first block, and the front end of the third block is fitted into the rear end of the second block.

[0044] The first and second blocks are equipped with push-pull and pull jacks 37 having a pin structure on both ends, and the second and third blocks are also equipped with push-pull and pull jacks 37 arranged and connected in multiple tiers in the vertical direction.

[0045] As shown in FIG. 4, the lower propulsion structure shield machine 35 is composed of left and right side wall plates 1a and a bottom plate 1b that is approximately the same length as the side wall plates 1a and connects them. The machine body is divided into a plurality of parts in the front-rear direction with an opening at the top, and the front end of the rear machine body as the tail section 19 is fitted into the rear end of the front machine body as the front section 18, and can be bent at the mutual center bending section 34. A movable divided blade hole 16 that is extended forward by a slide jack 17 is provided at the front end of the front section, and the above-mentioned Front end of tail section 19 The propulsion jacks 3 are arranged vertically from the front to the rear, and the propulsion jacks are extended via press bars 26 to the laying box body 4 to generate a propulsion reaction force and move the vehicle forward. The front section 18 and the tail section 19 are connected by a towing jack 31.

[0046] The lower-thrust structure shield machine 35 has a sliding retaining plate at the front end of the front section 18 to form a movable split blade 16.

[0047] As shown in Figures 4 and 5, the slide and support structure connecting the lower propulsion structure shield machine 35 and the upper propulsion structure shield machine 36 has upper propulsion structure slide rails 48 fixedly installed on the inside of the upper ends of both sides of the front part 18 and tail part 19 of the lower propulsion structure shield machine 35 so that the upper propulsion structure shield machine 36 can slide forward. The triangular members are fixing materials for the rails.

[0048] The structure of the upper propulsion structure sliding rail 48 is not particularly limited as long as it allows the upper propulsion structure shield machine 36 to move forward relative to the lower propulsion structure shield machine 35, but it is also possible to provide transfer wheels on the upper propulsion structure shield machine 36 and allow it to slide on rails like a railway.

[0049] The members protruding from the lower ends of both sides of the front section 18 and tail section 19 of the upper propulsion structure shield machine 36 are upper propulsion structure support members 49 that contact the upper end of the lower propulsion structure shield equipment and support the upper propulsion structure shield machine 36.

[0050] A pointed protruding portion is provided from the top of the upper propulsion structure slide rail 48 toward the outside. Similarly, a pointed protruding portion is similarly provided from the bottom of the upper propulsion structure support member 49 toward the inside, with a gap 50 provided between them. The presence of this gap 50 allows the upper propulsion structure shield machine 36 to follow any left and right swings that occur when it advances.

[0051] As described above, the upper propulsion structure slide rail 49 and the upper propulsion structure support member 49 each have a pointed protruding portion at the end, so that even if the upper propulsion structure shield machine 36 swings left and right beyond the gap 50, the protruding portions will abut against each other, preventing the upper propulsion structure shield machine from slipping off the lower propulsion structure shield machine.

[0052] In the figure, reference numeral 47 denotes an iron plate for preventing soil and sand from entering the connection between the upper-pull structure shield machine 36 and the lower-pull structure shield machine 35.

[0053] The procedure from advancing the open shield machine to installing the concrete box will be described. The first step is before advancing the open shield machine 1, and the second step is advancing the first block 36a of the top-end advancing structure shield machine 36.

[0054] Although not shown, an excavator 6 is placed in front of the open shield machine 1, and excavates while forming a slope in the ground at the face up to the vicinity of the lower end of the top-pull structure shield machine. As the excavation progresses, the rear end of the first pushing / pulling jack of the first block is extended, and the frictional resistance between the sides of both the first and second blocks and the ground in contact with them is used as a thrust reaction force to move the first block forward.

[0055] The third step is to propel the second block 36b, by contracting the rear end of the first propulsion and traction jack 37 while extending the rear end of the second propulsion and traction jack 37, thereby using the frictional resistance between both sides of the first and second blocks and the ground in contact with them as a reaction force to move the second block 36b forward.

[0056] The fourth step is to advance the third block 36c, and while shortening the rear end of the second advancing / tracting jack, the third block 36c is advanced by using the frictional resistance between both sides of the first block 36a and the second block 36b and the ground in contact with them as a reaction force. Also, while advancing the third block 36c, backfilling 5 is performed on the rear part of the third block.

[0057] The fifth step is a step of propelling the lower-propelling structure shield machine a propelling length equivalent to one cycle of the upper-propelling structure shield machine 36 after the propelling of one cycle of the upper-propelling structure shield machine 36 has been completed.

[0058] The upper-pull-through shield machine 36 is stopped, and the excavator 6 placed in front excavates while forming a slope in the ground at the face of the lower-pull-through shield machine 35, and at the same time, the slide jack 17 attached inside the movable split blade 16 is extended to extend the movable split blade 16 forward to retain the side ground. Simultaneously with the above operation, the lower-pull-through shield machine 35 extends the push jack 3 to press it against the press bar 26, and applies a push reaction force to the rear box body 4 to move forward. Also, as it moves forward, backfill grouting material 29 is filled into voids that occur in the ground.

[0059] Steps 6 to 8 are the same as steps 2 to 4, and step 9 is the same as step 5. Steps 10 to 13 are the same as steps 6 to 9.

[0060] As described above, the upper-propulsion structure shield machine 36 propels itself like an inchworm, using the frictional resistance between each block and the ground in contact with them as a reaction force, and the lower-propulsion structure shield machine 35 advances by repeating the above-mentioned work according to the length of one cycle of the upper-propulsion structure 36.

[0061] While performing the above-mentioned pushing operation, after the lower-pull structure shield machine 35 pushes one box body, as shown in the 14th step, the pushing jack 3 is retracted and a new box body 4 is installed inside the tail 20. The above-mentioned operations are repeated to lay the box bodies in the ground.

[0062] Next, a second embodiment of the open shield machine of the present invention will be described. As shown in Figures 11 to 15, the planar shapes of the upper and lower propulsion structures are the same as those of the first embodiment of the present invention, and this is an open shield machine in which the width of the upper propulsion structure shield machine 36 is larger than the width in the cross-sectional direction of the lower propulsion structure shield machine.

[0063] By making the width of the upper-pullthrough structure shield machine 36 larger than the width of the lower-pullthrough structure shield machine 35, for example, when constructing deep, loose sandy ground, even if the ground near the rear side plate of the cutting edge of the lower-pullthrough structure shield machine 35 collapses due to excavation near the bottom plate of the cutting edge, there is no risk of loosening reaching the ground surface at the top end of the upper-pullthrough structure shield machine 36, as the width of the upper-pullthrough structure shield machine 36 is made larger.

[0064] As shown in Figure 15, in cases where the excavation depth is deep and the ground is loose, such as sandy ground, the cutting edge of the upper-pull-through structure shield machine 36 is positioned in front of the tip of the movable split cutting edge 16 of the lower-pull-through structure shield machine 35, and the face ground slope 44 of the cutting edge 2 parts of the upper-pull-through structure shield machine 36 is made large and concave, and both ends of the ground slope near the toe can be held down by the movable split cutting edge 16 of the lower-pull-through structure shield machine and the flat ground parts 46 on either side of it, thereby maintaining the stability of the slope.

[0065] Furthermore, by making the gradient of the face ground slope 44 at the cutting edge 2 of the upper-propelled structure shield machine small according to the face ground conditions, the stability of the excavation face ground slope can be more safely maintained. Note that the work procedure is the same as that of the first embodiment of the invention, so a description thereof will be omitted.

[0066] In this embodiment, as shown in FIGS. 16 to 20, an upper propulsion structure shield machine 36 tooA sliding retaining plate 39 is provided at the front end of the front part to form a movable split cutting edge.

[0067] The upper-propulsion structure shield machine 36 consists of a first block consisting of a front main frame 41 and sliding retaining plates 39 arranged in multiple stages in the vertical direction on both sides of the front main frame 41, and a second block consisting of a jack tail section, and each block is wider than the lower structure section.

[0068] The slide retaining plate 39 of the first block and the main frame 41 are connected by a slide propulsion jack having a pin structure on both ends, and the main frame 41 of the first block and the second block are connected by a propulsion / traction jack 43 having a pin structure on both ends.

[0069] The upper-propulsion structure shield machine 36 and the lower-propulsion structure shield machine 35 are connected by a slide and support mechanism of the upper-propulsion structure shield machine 36 shown in Figures 4 and 5, similar to the first embodiment of the invention.

[0070] The lower-propulsion-structure shield machine 35, like the first embodiment, is made up of left and right side wall panels 1a and a bottom plate 1b that is approximately the same length as the side wall panels 1a and connects them, the machine body is divided into multiple parts in the front-to-rear direction with an opening at the top, the front end of the rear machine body as the tail section 19 is fitted into the rear end of the front machine body as the front section 18, and can be bent at the mutual center bending section 34, the front end of the front section is provided with a movable divided blade mouth 16 that is extended forward by a slide jack 17, the propulsion jacks 3 are arranged vertically from the rear end of the front section to the rear, and the propulsion jacks are extended via a press bar 26 to the laying box body 4 to receive a propulsion reaction force and move forward. The front section 18 and the tail section 19 are connected by a towing jack 31.

[0071] Next, the procedure from advancing the open shield machine 1 to installing the box in this third embodiment will be described with reference to Figures 21 to 23. The first step is the state of the longitudinal side of the open shield machine 1 of this embodiment before advancing. The second step is the extension of the uppermost bent part sliding retaining plate 39, penetration into the face ground, and excavation of the face ground.

[0072] Although not shown in the figure, an excavator 6 is placed in front of the open shield machine, and the excavator 6 excavates while forming an excavation slope on the ground at the face. Meanwhile, of the bent-section sliding earth retaining plates 39 arranged vertically in multiple stages on both sides of the front main frame 41 of the first block, the sliding propulsion jack 42 is extended forward to extend the uppermost bent-section sliding earth retaining plate 39, and the tip of the bent-section sliding earth retaining plate 39 is inserted into the ground at the face.

[0073] Similarly, in the third and fourth steps, the slide propulsion jacks 42 are extended to drive the second stage sliding earth retaining plate 39 and the third stage bending portion sliding earth retaining plate 39, respectively, and their tips are inserted into the face ground.

[0074] In the fifth step, the frictional resistance between the center bend slide retaining plate 39 and the ground in contact with it is used as a reaction force, and all the slide propulsion jacks 42 are contracted while the propulsion and traction jack 43 of the second block, which is the jack tail section 40, is extended to move the main frame 41 of the first block forward.

[0075] In a sixth step, the pushing and pulling jack 43 of the jack tail section 40 is retracted to move the jack tail section 40 forward. At the same time, the rear end of the jack tail section 40 is backfilled.

[0076] Next, while forming a slope on the ground face of the lower-pull structure shield machine 35 and excavating with the excavator 6, the shield jack 3 is extended to apply a thrust reaction force to the rear laying box body via the press bar 26, thereby propelling the lower-pull structure shield machine 35 forward.

[0077] In addition, backfill injection material 29 is filled into any voids that occur in the ground as the lower-pull structure shield machine 35 advances.

[0078] Although not shown, similarly to the first embodiment, after the lower propulsion structure shield machine 35 has completed moving forward by one box length, the shield jack 3 is retracted and a new box 4 is installed inside the tail 20.

[0079] The above steps are repeated to lay the box in the ground. [Explanation of symbols]

[0080] 1. Open shield machine 1a...Side wall plate 1b...Bottom plate 3...Propulsion jack (shield jack) 4...Concrete box 5...Backfill soil 9…Bearing wall 16…Movable split cutting edge 17...Slide jack 18...Front section 19...Tail section 20...Inside of tail 21... Center-bending jack 24... Rear retaining plate 25...Bulkhead 26...Press bar (press angle) 27... Lifting machine 28... Grout hole 29…Backfill injection material 30…Steel sheet pile 31...Towing jack 34... Center bending part 35... Lower propulsion structure shield machine 36...Upper thrust structure shield machine 36a...1st block 36b...2nd block 36c...3rd block 37...Pushing and towing jack (pin jack) 38... Fitting section (upper thrust structure shield machine) 39...Slide retaining plate 40...Jack tail section 41…Front body frame 42...Slide propulsion jack (pin jack for connecting the slide retaining plate and the front body frame) 43... Propulsion / towing jack (pin jack for connecting the front body frame and the jack / tail section) 44...Upper thrust structure shield machine face slope 45... Lower thrust structure shield machine face slope 46... Flat ground (same height as the top of the lower thrust shield machine) 47... Steel plate to prevent soil from entering the connecting section 48... Rail for sliding the upper propulsion structure 49...Upper propulsion structure support member 50...Joint gap

Claims

1. A lower-propulsion structure shield machine, which is made up of left and right side wall panels and a bottom panel that connects the left and right side wall panels and is approximately the same length as the side wall panels, has a body with an opening at the top, has a front section for excavating and a tail section for installing the concrete box, and has propulsion jacks arranged vertically on the left and right from the front end of the tail section toward the rear, and uses the propulsion reaction force on the box to move forward; The upper propulsion structure shield machine is a machine with openings on the front, rear, top and bottom, which is divided into divided blocks at different positions in the extension direction of the lower propulsion structure shield machine, and each divided block is connected with a propulsion and traction jack, and each block moves forward in sequence using the frictional resistance between the side plates divided by the divided blocks and the ground in contact with them as a propulsion reaction force. An open shield machine characterized in that, as a sliding and support structure connecting a lower propulsion structure shield machine and an upper propulsion structure shield machine, upper propulsion structure sliding rails are fixedly installed on the inside of the upper ends of both sides of the front and tail parts of the lower propulsion structure shield machine so that the upper propulsion structure shield machine can slide forward, while upper propulsion structure support members are provided from the lower ends of both sides of the front and tail parts of the upper propulsion structure shield machine to contact the upper end of the lower propulsion structure shield equipment and support the upper propulsion structure shield machine, and a pointed protrusion is provided extending outward from the upper propulsion structure sliding rails, and a pointed protrusion is provided extending inward of the upper propulsion structure support member, with a gap secured between them.

2. 2. The open shield machine according to claim 1, wherein the divided block of the upper propulsion structure shield machine comprises a front section, a jack section, and a tail section.

3. 3. An open shield machine according to claim 1 or 2, wherein a slide rail is provided on the lower propulsion structure shield machine, and the upper propulsion structure shield machine is installed on the slide rail so as to be movable forward.

4. 3. An open shield machine according to claim 1 or 2, wherein the upper-propulsion structure shield machine has a width greater than that of the lower-propulsion structure shield machine.

5. An open shield machine as described in claim 1 or claim 2, wherein the lower propulsion structure shield machine and the upper propulsion structure shield machine have a sliding retaining plate at the front end of the front section to form a movable split blade opening.

6. A method for laying a box using the open shield machine according to claim 1 or 2, comprising the steps of: A step of excavating a face of a shield machine having an upper thrust structure; a step of extending a first thrust / traction jack to move the front part of the upper thrust structure shield machine forward by using the frictional resistance between the jack part and the ground and the tail part side plate as a reaction force; a step of using frictional resistance between the front section, the tail section, and the ground as a reaction force to contract the first propulsion / towing jack, extend the second propulsion / towing jack, and move the jack section forward; a step of shortening the second propulsion / towing jack by using frictional resistance between the front section, the jack section, and the ground as a reaction force, and moving the tail section forward; and then backfilling the rear end of the tail portion. A step of extending a shield jack of the lower-thrust shield machine while excavating the ground at the cutting edge of the lower-thrust shield machine and advancing the lower-thrust shield machine; The open shield machine excavates the area while repeating this process. A method for laying a concrete box using an open shield machine, characterized in that after the open shield machine has advanced one box length, the shield jack is retracted and the box is buried in the ground while being installed within the tail section of the lower-propulsion structure shield machine.

7. The process of advancing the front section comprises the steps of excavating the ground at the cutting edge of the upper-pull structure shield machine, sequentially extending a sliding earth retaining plate provided at the front end of the front section to form a movable divided cutting edge, and using the frictional resistance between the sliding earth retaining plate and the ground in contact with it as a reaction force, contracting the slide jack and extending the push jack to advance. This is a method for laying a concrete box using an open shield machine as described in claim 6.

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