JP4908008B2 - Widening structure of tunnel - Google Patents

Description

  The present invention relates to a tunnel widening structure for partially widening a tunnel.

  Conventionally, when building a road tunnel with the shield method, when partially expanding an emergency parking zone or branching junction, etc., a shield excavator with a widening function such as a method of manually cutting and expanding the ground from the pit and a copy cutter, etc. The construction method using was adopted.

  However, this construction method has a safety problem because the construction period is extended only for the period required for ground improvement and it is a manual work outside the segment, so in recent years, when building a main tunnel, Forming a part of the side wall of the existing shield tunnel and the method of widening the tunnel cross section by pushing out the side of the segment while cutting with the jet of "multi-injection cutting system" A cylindrical part protruding in the direction opposite to the extrusion direction is joined to the peripheral part on the inner wall side of the extrusion segment part composed of at least one extrudable segment that can be extruded to form a box-like block body, and then the block body A tunnel widening method (Patent Document 2) has been developed that pushes out the shield tunnel to the outside.

JP 2003-328695 A JP 2004-027711 A

  However, in the widening method for extruding a part of the tunnel described above, as shown in FIG. 7A, the widened portion 100 pushed out of the tunnel and the remaining portion 101 that is not pushed out. Since the contact surfaces in the circumferential direction are in contact with each other with flat surfaces parallel to the extrusion direction of the widened portion 100, a large thrust is required because the resistance when pushing out the widened portion 100 is large. In addition, there is a problem that an increase in the size of the reaction force support portion and the like causes an increase in cost, and the remaining portion 101 has an adverse effect such as a dripping phenomenon.

  An object of the present invention is to provide a widening structure of a tunnel that can reduce the resistance between the circumferential contact surfaces (edge cutting portions) between the widened portion and the remaining portion to reduce the required thrust and has no adverse effect on the remaining portion. And

In order to achieve such an object, the widening structure of the tunnel according to the present invention includes a tunnel widening structure in which a part of an existing lining member is pushed out in the radial direction of the tunnel to widen the tunnel, and the existing lining member to be extruded is pushed out. that the contact surface between the remaining portions of the existing lining member in contact with the circumferential end surface of the widened portion and the enlarged width portion of is formed to have an inclination angle with respect to the extrusion direction of the widened portion of the contact surface Features.

The wider section is located at the side wall of the tunnel, the inclination angle is characterized in that it is set on the contact surface and at least above the widened portion and the remaining portion.

  In addition, there is provided a filler supply means for supplying a filler to a circumferential space formed between the contact surfaces of the widened portion and the remaining portion when the widened portion is pushed out.

  According to the widening structure of the tunnel of the present invention, when the widened portion is pushed out in the radial direction (outward) of the tunnel, the resistance between the circumferential contact surfaces (edge cutting portions) between the widened portion and the remaining portion is inclined. The required thrust can be reduced by reducing the distance. Accordingly, the propulsion jack of the widened portion and its reaction force support portion can be reduced in size, and the cost can be reduced. Further, the adverse effect on the remaining portion can be avoided by reducing the resistance.

  Hereinafter, the widening structure of a tunnel according to the present invention will be described in detail with reference to the accompanying drawings.

  1 is a half sectional view of a tunnel showing Example 1 of the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, FIG. 3 is an operational state diagram of FIG. 2, and FIGS. It is process drawing.

  As shown in FIG. 1, an inner wall G of a tunnel (tunnel diameter is 16 m, for example) excavated by a mud shield excavator (tunnel excavator) or the like (not shown) has a number of segment rings as lining members. 1 (the width dimension of one segment ring 1 is 1.5 m, for example). The segment ring 1 includes a plurality of segments (pieces) 2 having a general structure made of concrete and a predetermined number (one in the figure) of widening segments (pieces) 3 having a special structure to be described later made of iron. It is assembled in a ring shape. The widening segment 3 extends over the plurality of segment rings 1 by the length of the tunnel to be widened (for example, 60 m), and the circumferential position of each segment ring 1 (in the illustrated example, one side of the segment ring 1). It is provided to match.

  The widening segment 3 is a main portion (segment) composed of three intermediate blocks 3a, 3b, 3c excluding the upper and lower end portions 3d, 3e (joint portion with the general structure segment 2: remaining portion) in the figure. The main body: the widened part) can be slid (extruded) outside the tunnel (in the radial direction of the tunnel). When sliding, the three blocks 3a, 3b, 3c, which are bolted together, slide together. It is supposed to be. In the illustrated example, the upper and lower end portions 3d and 3e are also constituent elements of the widening segment 3. However, the widening segment 3 is constituted only by the main portions 3a, 3b and 3c, and the upper, The lower end portions 3d and 3e may be obtained by appropriately cutting the segment 2 having a general structure.

  In this embodiment, the contact surfaces of the uppermost block 3a of the three blocks 3a, 3b, and 3c and the upper end portion 3d contacting the circumferential end surface of the block 3a can be pushed out. For example, it is formed on the inclined surfaces 3aa and 3db having an inclination angle of 10 ° or less. On the other hand, the contact surfaces 3ca and 3eb in the circumferential direction between the lowest block 3c and the lower end portion 3e are formed as flat surfaces parallel to each other in the extrusion direction. This is in consideration of the weight of the widening segment 3 and the like. This is because the effect formed on the inclined surface is thin, and depending on the circumferential position where the weight of the widening segment 3 need not be taken into account, the inclined surface may be formed on both the left and right sides of the widening segment 3. .

  In each of the blocks 3a, 3b, 3c, oscillating cutter heads 4a, 4b, 4c and their cutter driving parts (supporting parts) 5a, 5b, 5c are stored so as to be pushed out of the tunnel. Each cutter drive section 5a, 5b, 5c is provided with a flat-plate-shaped jack support section (first installation section) 11 for detachably installing a digging jack (first drive means) 10 for driving a cutter head, which will be described later. On the other hand, each of the blocks 3a, 3b, and 3c is provided with a push-out jack (second drive means) 12 to be described later for extruding the corresponding cutter heads 4a, 4b, and 4c for the respective cutter driving portions 5a, 5b, and 5c. A plate-frame-like jack support portion (second installation portion) 13 that can be installed is provided. In the illustrated example, one excavation jack 10 is installed on the jack support 11 and two extrusion jacks 12 are installed on the jack support 13. Of course, the number of the excavation jacks 10 and the extrusion jacks 12 is not particularly limited.

  As shown in FIG. 2, each of the cutter heads 4a, 4b, and 4c has a plurality of cutter bits 8 fixed on a vertically long rectangular face plate 7 and is indicated by arrows in FIG. It can swing up and down (circumferential direction of the segment ring 1). Further, as shown in FIG. 3, the rectangular face plate 7 is divided into a plurality of parts (three parts in the illustrated example) that can be expanded and contracted in the left and right direction (width direction of the segment ring 1), and is stored in each block 3a, 3b, 3c. When they are pushed out of the tunnel, they can be separated from each other to expand the excavation range in the width direction of the widening segment 3. (State of FIG. 3).

  In FIG. 1, 9a is a supply port to which a mud pipe 14 described later is connected, and 9b is a discharge port to which a mud pipe 15 described later is connected. 2 and 3, three segment rings 1 are shown. At the time of widening, the widening segments 3 corresponding to, for example, 10 m of the tunnel length (about seven segment rings 1) are simultaneously operated.

  Because of this configuration, the state of FIG. 1 in which the widening segment 3 having the structure described above is assembled as a part of the segment ring 1 on the inner wall surface G of the tunnel excavated by the tunnel excavator (first step: for widening) When partially expanding the tunnel from the segment assembling step), first, as shown in FIG. 4 (a), the excavation jacks 10 are respectively installed on the jack support portions 11 of the cutter driving portions 5a, 5b, and 5c. The extrusion jacks 12 are installed on the jack support portions 13 of the blocks 3a, 3b, and 3c, respectively (second process: first and second drive means installation process). In addition, the mud pipe 14 is connected to the supply port 9a, and the mud pipe 15 is connected to the discharge port 9b.

  Next, as shown in FIG. 4 (b), the cutter heads 4a, 4b, 4c are rocked in the vertical direction in the figure by the excavating jacks 10, respectively, and the cutter heads 4a, 4b are pushed by the pushing jacks 12, respectively. , 4c are pushed out of the respective tunnels 3a, 3b, 3c from the respective blocks 3a, 5b, 5c (third step: cutter head pushing step). At this time, muddy water is supplied to and discharged from the face of the tunnel inner wall. At this stage, a sleeper 19 is installed on the lower inner surface of the segment ring 1, and a reaction force support 20 for installing a slide jack 18 described later is installed on the upper inner surface of the segment ring 1.

  Next, as shown in FIG. 5 (a), all the extrusion jacks 12 that have become unnecessary and a part of the jack support portion 13 are removed, and the widening segment 3 comprising the blocks 3a, 3b, 3c. The slide jack (third drive means) 18 is horizontally mounted with the extension pieces 16 interposed between the upper and lower ends of the main portion and the reaction force support portion 20 and the sleepers 19 (fourth step: third step). Drive means installation process). Moreover, the end plate 17 is arrange | positioned at the both ends of the main part in the segment 3 for widening extruded simultaneously collectively. Thereafter, the cutter heads 4a, 4b, and 4c are swung in the vertical direction in the figure by the respective excavating jacks 10 while the main portions of the respective widening segments 3 are slid outwardly from the tunnel by the slide jacks 18 so that the tunnels are partially formed. (5th process: widening segment slide process). Also at this time, muddy water is supplied to and drained from the face of the tunnel inner wall.

  Next, as shown in FIG. 5 (b), when the width is widened by a predetermined dimension (for example, 1 m), the widening work at that portion is finished, and then all the excavation jacks 10 and the slide jacks 18 are removed (sixth step). : Excessive portion (hatched portion in the figure) of the extension piece 16 and the inward protruding portion of the jack support portion 13 are crushed and removed together with the drive means removing step). In addition, the reaction force support portion 20 is also removed.

  Thereafter, the above steps are repeated to partially widen the tunnel for a predetermined length.

  As described above, in this embodiment, without performing ground improvement and without using a shield excavator having a widening function, the cutter heads 4a, 4b, 4c and the cutter driving units 5a, 5b, 5c are incorporated. Since the segment 3 is partially widened, it is safe to perform the widening operation in the segment ring 1, and the widening segment 3 includes the cutter heads 4a, 4b, 4c and the cutter driving portions 5a, 5b, 5c. It has a simple structure and is economical. Moreover, since the widening work can be performed in parallel with the tunnel main line excavation work by the shield excavator, the construction period can be shortened in combination with the effects of the cutter heads 4a, 4b, 4c having high cutting ability. Further, since the cutter heads 4a, 4b, and 4c are of a swing type, they can be manufactured at a lower cost than a rotary type, so that they can be left after partial widening, and the various jacks 10, 12, and 18 can be left after the widening operation is completed. There is also an advantage that it can be removed and collected and recycled.

  In this embodiment, when the main part of each widening segment 3 is slid outward from the tunnel in the fifth step described above to partially widen the tunnel, as shown in FIG. Further, since the contact surfaces of the uppermost block 3a and the upper end portion 3d contacting the circumferential end surface of the block 3a are formed on the inclined surfaces 3aa and 3db capable of pushing out the block 3a, the circumferential contact The resistance caused by the segment ring 1 being tightened by the earth pressure, the water pressure, or the like between the faces (edge cutting portions) is reduced, and the required thrust can be reduced. Therefore, the slide jack 18, the reaction force support portion 20, the sleeper 19 and the like can be downsized, and the cost can be reduced. Further, by reducing the resistance, it is possible to avoid an adverse effect on the upper end portion 3d such as a blistering phenomenon.

  Further, during widening work, muddy water is supplied to and discharged from the face portion of the tunnel inner wall via the widening segment 3, so that excavation can be performed safely while pressurizing the face portion. Moreover, since the jack 12 for extrusion which became unnecessary immediately after the cutter heads 4a, 4b, and 4c are extruded is removed, the jack 12 can be collected and recycled at an early stage. Further, the widening segment 3 is provided over a plurality of segment rings 1 for the width of the tunnel to be widened, and at the time of the widening work, a face plate 17 is provided at both ends, and a predetermined number of segment rings 1 minute are constructed. Therefore, the widening operation can be performed smoothly and quickly while avoiding the entry of earth and sand into the tunnel.

  Further, since a plurality of cutter heads 4a, 4b, 4c and their cutter driving portions 5a, 5b, 5c are built in the length direction of the widening segment 3 (three in the illustrated example), the cutter heads 4a, 4b, 4c are incorporated. In addition, the cutter driving units 5a, 5b, and 5c can be reduced in size and weight, and the widening segments 3 can be divided into a plurality of blocks (three in the illustrated example) to be easily handled. Further, since the cutter heads 4a, 4b, 4c can swing in the length direction of the widening segment 3, the excavation range in the length direction of the widening segment 3 can be expanded. Further, the rectangular face plate 7 with the cutter bit 8 of the cutter heads 4a, 4b, 4c is divided into a plurality of pieces so as to be able to contact and separate from each other in the width direction of the widening segment 3 (the tunnel length direction). When stored, they are stored compactly in contact with each other, while when pushed out of the tunnel, they can be separated from each other and the excavation range in the width direction of the widening segment 3 can be expanded.

  FIG. 6 is an enlarged cross-sectional view of a main part of a tunnel showing Embodiment 2 of the present invention.

  In the first embodiment, when the main portion of each widening segment 3 is slid outward from the tunnel to partially widen the tunnel, the inclined surfaces 3aa and 3db between the uppermost block 3a and the upper end portion 3d. A filler supply passage (filler supply means) 30a for supplying a filler such as grease is formed in the block 3a in the circumferential space i formed therebetween, and this filler supply passage 30a is formed as a filler supply pipe (filling). (Agent supply means) 30b is connected to a filler supply source (filler supply means) (not shown), and chamfering 3dc is applied to the inner peripheral corner of the inclined surface 3db of the upper end 3d (FIG. 6 ( In the case of a)), or instead of chamfering 3dc, the inner peripheral side of the uppermost block 3a is made smaller by the dimension L than in the case of FIG. 6A (in the case of FIG. 6B). It is an example. Other configurations are the same as those of the first embodiment.

  According to this, at the time of widening, by filling with grease or the like, it is avoided that earth and sand etc. enter the circumferential space portion a and the segment ring 1 (tunnel), and the chamfering is reduced by 3 cdc and the dimension L. Thus, the resistance can be further reduced by forming a gap in the portion.

  Needless to say, the present invention is not limited to the above-described embodiments, and various modifications such as a structural change of the filler supply means can be made without departing from the scope of the present invention. Moreover, this invention is not limited to the widening method of said each Example, It can apply also to various widening methods, such as the widening method of patent document 1 and patent document 2. FIG.

It is a half sectional view of a tunnel showing Example 1 of the present invention. It is the sectional view on the AA line of FIG. FIG. 3 is an operational state diagram of FIG. 2. It is process drawing of a tunnel widening construction method. It is process drawing of a tunnel widening construction method. It is a principal part expanded sectional view of the tunnel which shows Example 2 of this invention. It is comparative explanatory drawing of a prior art example and this invention.

Explanation of symbols

1 Segment ring 2 General segment 3 Widening segment 3a, 3b, 3c Block (widening part)
3d upper end (remaining part)
3e Lower end (remaining part)
3aa Inclined surface 3db Inclined surface 4a, 4b, 4c Cutter head 5a, 5b, 5c Cutter drive part (support part)
7 Rectangular face plate 8 Cutter bit 9a Supply port 9b Discharge port 10 Jack for excavation (first drive means)
11 Jack support part (first installation part)
12 Extrusion jack (second drive means)
13 Jack support part (second installation part)
14 Mud pipe 15 Mud pipe 16 Extension piece 17 End plate 18 Slide jack (third drive means)
19 Sleeper 20 Reaction force support part 30a Filler supply passage 30b Filler supply pipe A Circumferential space part

Claims (3)

In the tunnel widening structure in which a part of the existing lining member is extruded in the radial direction of the tunnel to widen the tunnel, the widening portion of the existing lining member to be pushed out and the existing lining member in contact with the circumferential end surface of the widening portion tunnel widening structure of the contact surface, characterized by comprising formed to have an inclination angle with respect to the extrusion direction of the widened portion of the contact surface with the remaining portion. The wider section is located at the side wall of the tunnel, the tunnel widening structure of claim 1, wherein the set in the contact surface between the inclined angle of at least above the widened portion and the remaining portion.   The filler supply means for supplying a filler to a circumferential space formed between the contact surfaces of the widened portion and the remaining portion when the widened portion is extruded is provided. 2. The widening structure of the tunnel according to 2.

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