Invert renewal method

Abstract

To provide an invert renewal method that can efficiently construct an invert by dividing a half cross section and shorten a construction period by improving construction efficiency.SOLUTION: An invert renewal method includes a first receiving surface forming step for forming a receiving surface on a foot of lining concrete of a travel lane, a first lining receiving installation step for installing a lining receiving part 31 by joining it to the receiving surface formed in the first receiving surface forming step, a second receiving surface forming step for forming a receiving surface on a foot of the lining concrete of a passing lane, a second lining receiving installation step for installing the lining receiving part 31 by joining it to the receiving surface formed in the second receiving surface forming step, a first invert installation step for installing an invert part 32 by joining it to the lining receiving part 31 installed in the first lining receiving installation step, and a second invert installation step for installing the invert part 32 by joining the invert part 32 installed in the first invert installation step to the lining receiving part 31 installed in the second lining receiving installation step.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an invert renewal method for renewing an invert of an existing tunnel. [Background technology]

[0002] Invert renewal work for existing tunnels can be carried out by "full section all-at-once construction," in which the existing tunnel is closed to traffic and the invert is constructed all at once across the entire width, or by "half section divided construction," in which the section is divided near the center of the existing tunnel while restricting traffic on one side while keeping the other lane in service (see Patent Document 1, for example). Regardless of whether it is a full section (full section closure) or half section (lane restriction), invert renewal work involves traffic restrictions and has a large social impact, so it is essential to shorten the restriction period. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-124019 A Summary of the Invention [Problem to be solved by the invention]

[0004] Invert renewal work involves excavating the bottom of the existing tunnel, pouring concrete, backfilling, and restoring the pavement. Since this work is carried out inside the tunnel where the construction space is limited, the problem is that the work is taking longer than expected due to reduced construction efficiency.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide an invert renewal method that can solve the above-mentioned problems and shorten construction time by improving construction efficiency. [Means for solving the problem]

[0006] The invert renewal method of the present invention is an invert renewal method for constructing an invert in an existing tunnel of a two-lane road consisting of a first lane and a second lane, and includes a block-shaped lining receiving part having a lining receiving surface and an invert joint surface formed therein, and an arc-shaped invert part whose longitudinal end surfaces respectively become an end joint surface and a central joint surface, which are fabricated as precast members, and includes a first receiving surface forming step of chipping the foot of the lining concrete of the first lane to form a receiving surface, a first lining receiving installation step of orienting the invert joint surface toward the interior space and joining the lining receiving surface to the receiving surface formed in the first receiving surface forming step to install the lining receiving part, and a second lining receiving installation step of chipping the foot of the lining concrete of the second lane to form the receiving surface. The method is characterized by comprising: a second receiving surface forming process; a second lining receiving installation process in which the invert joint surface is directed toward the inner space and the lining receiving surface is joined to the receiving surface formed in the second receiving surface forming process to install the lining receiving part; a first invert installation process in which the end joint surface is joined to the invert joint surface of the lining receiving part installed in the first lining receiving installation process to install the invert part; and a second invert installation process in which the central joint surface is joined to the central joint surface of the invert part installed in the first invert installation process, and the end joint surface is joined to the invert joint surface of the lining receiving part installed in the second lining receiving installation process to install the invert part. Furthermore, in the invert renewal method of the present invention, the invert section may be made to have a curved shape with a radius similar to that of the existing invert of the existing tunnel, be thinner than the existing invert, and be installed above the location where the existing invert is installed. Furthermore, in the invert renewal method of the present invention, in the first invert installation process, the invert portion may be installed with the end joint surface as a fulcrum, and in the second invert installation process, the invert portion may be installed with the central joint surface as a fulcrum. Effect of the Invention

[0007] According to the present invention, an invert can be constructed efficiently by half-section division construction, and the construction period can be shortened by improving construction efficiency. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a cross-sectional view of a tunnel explaining the invert renewal method according to the present invention. [Diagram 2] This is a cross-sectional view of a tunnel explaining the first stage process of the invert renewal method according to the present invention. [Diagram 3] A diagram showing the configuration of the lining receiving part. [Figure 4] This is a cross-sectional view of a tunnel explaining the second stage process of the invert renewal method according to the present invention. [Diagram 5] FIG. 2 is a diagram showing a configuration of an inverter unit. [Figure 6] A diagram showing the first inverter installation process. [Figure 7] This is a cross-sectional view of a tunnel explaining the third and fourth stages of the invert renewal method of the present invention. [Figure 8] A diagram showing the second inverter installation process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Next, a mode for carrying out the present invention (hereinafter simply referred to as an "embodiment") will be specifically described with reference to the drawings. The invert renewal method of this embodiment is a method for renewing an existing invert 2 shown in Fig. 1(a), which was constructed in an existing tunnel 1 using cast-in-place concrete, to a precast invert 3 shown in Fig. 1(b). The existing invert 2 shown in Fig. 1(a) is constructed in a predetermined curved shape (radius = R) in a standard pattern for ground grade D1, for example.

[0010] Invert 3 shown in Fig. 1(b) is fabricated by precasting lining support portion 31 and invert portion 32 on-site. The curved shape of invert portion 32 is the same as that of existing invert 2 (radius = R), and the center point C of the curved shape is moved upward, i.e., the installation position is moved upward. Invert portion 32 is constructed of high-strength concrete to ensure its strength, and is thinner than existing invert 2. Lining support portion 31 and invert portion 32 may be constructed of reinforced concrete to ensure its strength.

[0011] The invert renewal method of this embodiment allows the installation depth of the invert 3 to be shallower than that of the existing one by moving the center point C of the curved shape upward and making it thinner, thereby reducing the amount of excavation.

[0012] Steps S1 to S8 shown in Fig. 2(a) to (h) indicate the construction process for the first stage of ancillary equipment removal and lining construction work. <Step S1, Fig. 2(a)> The existing tunnel 1 to be updated is a two-lane road consisting of a driving lane (first lane) and an overtaking lane (second lane). In step S1, the driving lane is restricted using traffic control equipment such as cones 4, various cables laid on the shoulder of the driving lane are relocated, and the guard passage 5 and side drain 6 are removed.

[0013] <Step S2, Fig. 2(b)> Step S2 is a first receiving surface formation process in which the foot of the lining concrete 7 on the travel lane side exposed by excavation is chipped off to form a receiving surface. In the invert renewal method of this embodiment, the invert 3 is installed at a shallow depth, so the construction position is high and construction efficiency is improved.

[0014] <Step S3, Fig. 2(c)> Step S3 is a first lining receiving installation step for installing the lining receiving part 31 as the left lining receiving part. Referring to FIG. 3, the lining receiving part 31 is a block-shaped precast member having a side shape of a substantially pentagon, in which a resting surface 311, a lining receiving surface 312, and an invert joint surface 313 are formed. The resting surface 311 is a surface to be placed on the bedrock, and a height adjustment bolt 8 capable of adjusting the protruding length is erected. The lining receiving surface 312 is a surface to be joined to the receiving surface of the lining concrete 7, and a lining temporary receiving bolt 9 capable of adjusting the protruding length is erected. The invert joint surface 313 is a joint surface with the invert part 32, and a joint reinforcing bar 10 is erected. A connecting hole 314 is formed on the side surface of the lining receiving part 31, into which a connecting pin (not shown) is inserted to connect to the adjacent lining receiving part 31.

[0015] In the first installation step, the lining receiving surface 312 faces the receiving surface of the lining concrete 7 formed in step S2, and the invert joint surface 313 faces the inner space, and the lining receiving part 31 is installed on the bedrock with the placement surface 311 facing down. In the first installation step, the connecting pin is pushed into the connecting hole 314 with a jack or the like, and the lining receiving part 31 is connected to the adjacent lining receiving part 31 in the tunnel axis direction. In the first installation step, the lining receiving part 31 is leveled with the height adjustment bolts 8, and then the lining temporary receiving bolts 9 are adjusted to temporarily support the load of the lining concrete 7. In the first installation step, the gap between the back and lower ends of the lining receiving part 31 and the bedrock, and the gap between the upper end of the lining receiving part 31 and the receiving surface of the lining concrete 7 are filled with a filler 11 such as non-shrink grout.

[0016] <Step S4, Fig. 2(d)> In step S4, temporary drainage pipes 12 are laid to connect the gutters 6 on both sides of the construction section, and then backfilling is performed, followed by installation of temporary pavement 13, temporary protective fences 14, and temporary curbs. The first phase of construction on the travel lane side is completed through steps S1 to S4, and the travel lane restrictions are lifted.

[0017] <Step S5, Fig. 2(e)> In step S5, the passing lane is restricted by using control equipment such as cones 4, various cables laid on the shoulder of the passing lane are relocated, and the inspection gallery and drain 6 are removed.

[0018] <Step S6, Fig. 2(f)> Step S6 is a second receiving surface forming step in which the foot of the lining concrete 7 on the passing lane side exposed by excavation is chipped away to form a receiving surface.

[0019] <Step S7, FIG. 2(g)> Step S7 is a second lining receiving installation step in which the lining receiving part 31 is installed as a right lining receiving part. In the second lining receiving installation step, the lining receiving part 31 is installed symmetrically in the same process as the first lining receiving installation step.

[0020] <Step S8, FIG. 2(h)> In step S8, a temporary drainage pipe 12 is laid to connect the gutters 6 on both sides of the construction section, and then backfilling is performed, followed by installation of temporary pavement 13 and temporary curb stone installation 16. The first phase of construction on the passing lane side is completed by steps S5 to S8, and the passing lane is opened.

[0021] Steps S9 to S16 shown in Fig. 4(a) to (h) show the construction process of the invert construction work on the travel lane side in the second phase. <Step S9, FIG. 4(a)> In step S9, the traffic lanes are restricted and a central protective fence 17 is installed.

[0022] <Step S10, FIG. 4(b)> In step S10, the temporary pavement 13, the temporary protective fence 14, and the temporary curb stones installed in step S4 are removed, and the pavement 18 of the travel lane is also removed. Step S10 also includes the removal of the temporary curb stones, the temporary pavement, the drainage pipes, and the backfill material.

[0023] <Step S11, FIG. 4(c)> In step S11, a driving lane is excavated to the installation depth of the invert 3 using heavy machinery or the like.

[0024] <Step S12, FIG. 4(d)> In step S12, a temporary retaining wall 19 made of an L-shaped steel material or the like is installed.

[0025] <Step S13, FIG. 4(e)> Step S13 is a first invert installation step for installing the invert part 32 in the travel lane. Referring to FIG. 5, the invert part 32 is a precast member fabricated to have an arc shape (radius=R) equivalent to that of the existing invert 2. The end faces of the invert part 32 in the longitudinal direction are an end joint surface 321 on one side and a central joint surface 322 on the other side. The end joint surface 321 is a joint surface with the invert joint surface 313 of the lining receiving part 31, and a joint reinforcing bar 10 is erected. The central joint surface 322 is a joint surface with the invert part 32 installed in the passing lane, and a bolt joint steel member 20 is embedded therein. The bolt joint steel member 20 is also embedded on both side surfaces of the invert part 32. A cotter 21 is formed on the peripheral surface of the invert part 32. The cotter 21 is a through hole penetrating the back surface, or a level adjustment hardware into which a level bolt is screwed is embedded.

[0026] The invert part 32 is transported to the construction section with its longitudinal direction facing the tunnel axis, and as shown in FIG. 6(a), it is rotated 90 degrees to face the end joint surface 321 toward the lining receiving part 31. In the first invert installation process, as shown in FIG. 6(b), the end joint surface 321 of the invert part 32 (end joint surface 321) where the joint reinforcing bar 10 is planted is aligned with the invert joint surface 313 of the lining receiving part 31. In the first invert installation process, as shown in FIG. 6(c), the invert part 32 is lowered with the end joint surface 321 as a fulcrum. Then, after adjusting the height with the level bolt of the cotter 21, the connecting part (bolt joint steel member 20) with the invert part 32 already installed adjacent to the tunnel direction is joined with a high-strength bolt or the like. In the first invert installation process, filler is used in the gap between the invert portion 32 (end joint surface 321) and the lining receiving portion 31 (invert joint surface 313) and in the gap between the back surface of the invert portion 32 and the bedrock. Ultra-fast hardening fiber reinforced concrete or high strength concrete is used as filler in the gap between the invert portion 32 (end joint surface 321) and the lining receiving portion 31 (invert joint surface 313). Non-shrink grout is used as filler in the gap between the back surface of the invert portion 32 and the bedrock.

[0027] <Step S14, FIG. 4(f)> In step S14, the central drainage pipe 22 is installed, a temporary retaining wall 23 is formed at the boundary with the passing lane, and the travel lane is backfilled.

[0028] <Step S15, FIG. 4(g)> In step S15, the side drain 6 and the temporary protective fence 24 are installed, and the pavement 18 is laid on the travel lane.

[0029] <Step S16, FIG. 4(h)> In step S16, the central protective fence 17 is removed. The second stage of construction on the driving lane side is completed by steps S9 to S16, and the driving lane restrictions are lifted.

[0030] Steps S17 to S22 shown in Fig. 7(a) to (f) show the construction process of the invert construction work on the passing lane side in the third phase. <Step S17, FIG. 7(a)> Step S17 closes the passing lane and removes the passing lane pavement 18. Step S17 also includes removing temporary curbs, temporary pavement, drainage pipes, and backfill material.

[0031] <Step S18, FIG. 7(b)> In step S18, the central protective fence 17 is installed.

[0032] <Step S19, FIG. 7(c)> In step S19, a passing lane is excavated to the installation depth of the invert 3 using heavy machinery or the like.

[0033] <Step S20, FIG. 7(d)> Step S20 is a second invert installation step of installing the invert portion 32 in the passing lane. In the second invert installation step, the invert portion 32 is installed symmetrically to the invert portion 32 installed in the driving lane.

[0034] The invert part 32 is transported to the construction section with its longitudinal direction facing the tunnel axis, and as shown in FIG. 8(a), it is rotated 90 degrees so that the end joint surface 321 faces the lining receiving part 31. In the second invert installation process, as shown in FIG. 8(b), the central joint surface 322 of the invert part 32 is abutted against the central joint surface 322 of the invert part 32 already installed in the travel lane. In the second invert installation process, as shown in FIG. 8(c), the invert part 32 is lowered with the central joint surface 322 as a fulcrum. In the second invert installation process, the height is adjusted using the level bolts of the cotter 21, and then the connecting part (bolt joint steel member 20) with the invert part 32 already installed adjacent in the tunnel direction is joined with a high-strength bolt or the like. Finally, in the second invert installation process, filler is used in the gap between the invert portion 32 (end joint surface 321) and the lining receiving portion 31 (invert joint surface 313) and in the gap between the back surface of the invert portion 32 and the bedrock. Ultra-fast hardening fiber reinforced concrete or high strength concrete is used as filler in the gap between the invert portion 32 (end joint surface 321) and the lining receiving portion 31 (invert joint surface 313). Non-shrink grout is used as filler in the gap between the back surface of the invert portion 32 and the bedrock.

[0035] <Step S21, FIG. 7(e)> Step S21 installs the central drain pipe 22 and backfills the passing lane.

[0036] <Step S22, FIG. 7(f)> In step S22, the gutters 6 and the curbs 25 are installed, various auxiliary facilities including the inspection gallery are restored, and the pavement 18 is laid on the passing lane.

[0037] Steps S23 to S24 shown in Figs. 7(g) to (h) show the construction process of the incidental facilities restoration work in the fourth stage.

[0038] <Step S23, FIG. 7(g)> In step S23, the traffic lanes are restricted, and various auxiliary facilities including the guard passage 5 are restored.

[0039] <Step S24, FIG. 7(h)> In step S24, the restrictions on the driving lane and the passing lane are lifted, and the construction is completed.

[0040] As described above, this embodiment is an invert renewal method for constructing an invert 3 in an existing tunnel 1 of a two-lane road consisting of a driving lane (first lane) and an overtaking lane (second lane), and includes a block-shaped lining receiving portion 31 having a lining receiving surface 312 and an invert joint surface 313 formed therein, and an arc-shaped invert portion 32 having longitudinal end surfaces which respectively become an end joint surface 321 and a central joint surface 322, which are fabricated as precast members, and includes a first receiving surface forming step (step S2) for chipping the foot of the lining concrete 7 of the driving lane to form a receiving surface, a first lining receiving installation step (step S6) for orienting the invert joint surface 313 toward the interior space side and joining the lining receiving surface 312 to the receiving surface formed in the first receiving surface forming step to install the lining receiving portion 31, and a second lining receiving installation step (step S7) for chipping the foot of the lining concrete 7 of the overtaking lane to form a receiving surface, The method includes a second receiving surface formation process (step S6) for forming a receiving surface, a second lining receiving installation process (step S7) for installing the lining receiving part 31 by facing the invert joint surface 313 toward the inner space and joining the lining receiving surface 312 to the receiving surface formed in the second receiving surface formation process, a first invert installation process (step S13) for installing the invert part 32 by joining the end joint surface 321 to the invert joint surface 313 of the lining receiving part 31 installed in the first lining receiving installation process, and a second invert installation process (step S20) for installing the invert part 32 by joining the central joint surface 322 to the central joint surface 322 of the invert part 32 installed in the first invert installation process, and joining the end joint surface 321 to the invert joint surface 313 of the lining receiving part 31 installed in the second lining receiving installation process. This configuration allows the invert 3 to be constructed efficiently by dividing the half section into two parts, and the construction time can be shortened by improving construction efficiency. By constructing the invert 3 with two lining receiving parts 31 and two invert parts 32, the weight of each part can be reduced, making it easier to handle inside the tunnel.

[0041] Furthermore, in this embodiment, the invert section 32 has a curved shape with a radius = R similar to that of the existing invert 2 of the existing tunnel 1, is made thinner than the existing invert 2, and is installed above the location where the existing invert 2 is installed. This configuration allows the invert to be installed at a shallower depth than before, reducing the amount of excavation and the amount of concrete. The installation depth can be set according to the site conditions, taking into account interference with auxiliary works (buried pipelines and side gutters). The strength of the invert part 32, which decreases when it is made thinner, can be compensated for by using high-strength concrete or reinforcement.

[0042] Furthermore, in this embodiment, in the first invert installation process, the invert portion 32 is installed with the end joint surface 321 as a fulcrum, and in the second invert installation process, the invert portion 32 is installed with the central joint surface 322 as a fulcrum. This configuration allows the invert section 32 to be precisely installed in the driving lane and the pushing lane.

[0043] The present invention has been described above based on the embodiment. This embodiment is merely an example, and it will be understood by those skilled in the art that various modifications are possible in terms of the combination of the respective components, and that such modifications are also within the scope of the present invention. [Explanation of symbols]

[0044] 1 Existing tunnels 2 Existing invert 3. Invert 7 Lining concrete 31 Lining support 32 Inverter 311 Placement surface 312 Lining receiving surface 313 Invert joint surface 321 End joint surface 322 Central joint surface

Claims

1. An invert renewal method for constructing an invert in an existing tunnel of a two-lane road consisting of a first lane and a second lane, A block-shaped lining receiving portion having a lining receiving surface and an invert joint surface, and an arc-shaped invert portion having longitudinal end surfaces which respectively become an end joint surface and a central joint surface are fabricated as precast members, A first receiving surface forming process of chipping a foot of the lining concrete of the first lane to form a receiving surface; A first lining receiving installation process in which the invert joint surface is directed toward the inner space side, and the lining receiving surface is joined to the receiving surface formed in the first receiving surface forming process to install the lining receiving part; A second receiving surface forming process of chipping a foot of the lining concrete of the second lane to form the receiving surface; A second lining receiving installation process in which the invert joint surface is directed toward the inner space side, and the lining receiving surface is joined to the receiving surface formed in the second receiving surface forming process to install the lining receiving part; A first invert installation process in which the end joint surface is joined to the invert joint surface of the lining receiving part installed in the first invert receiving installation process to install the invert part; An invert renewal method comprising: a second invert installation process for installing the invert section by joining the central joint surface to the central joint surface of the invert section installed in the first invert installation process, and joining the end joint surfaces to the invert joint surface of the lining receiving section installed in the second lining receiving installation process.

2. The invert renewal method described in claim 1, characterized in that the invert section is made to have a curved shape with a radius similar to that of the existing invert of the existing tunnel, is thinner than the existing invert, and is installed above the location where the existing invert is installed.

3. An invert renewal method as described in claim 1 or 2, characterized in that in the first invert installation process, the invert portion is installed using the end joint surface as a fulcrum, and in the second invert installation process, the invert portion is installed using the central joint surface as a fulcrum.

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