JPS62186000A - Improvement of method of assembling tunnel lining - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a method of assembling a tunnel lining.

The main method of widening tunnel segments in cohesive soils is the well-known and often tried tunneling technique, which has the advantage of leaving little or no voids around the tunnel lining that need to be filled with grout. be.

In non-cohesive soils, when digging a tunnel it is necessary to use a tunneling shield to support the tunnel by assembling each tunnel lining ring and then advancing the shield to lower this ring into the ground. leave it in As a result, a void previously occupied by the shield is created around the ring, which must subsequently be filled with grout to support the soil around the ring.

The present invention provides a method for assembling a tunnel lining using a shield for tunnel excavation, in which a ring made of segments is assembled, and a recess is made on the outer periphery of the ring at the tip of the ring in the forward direction along the tunnel. A ring consisting of segments, each segment having a recess in its outer periphery, is assembled within the shield, and the shield is advanced relative to the assembled ring until the rear end of the shield is located in the recess in the distal end of the ring, and the ring is moved around the ring. The ring is expanded and pressed against the tunnel by separating adjacent segments at at least one location, supporting the tunnel wall at that location against collapse, and inserting a supplementary segment between the adjacent segments. Provided is a method characterized by completing a ring.

Because the ring is expanded and pressed into the ground, the need for grouting around the ring is minimized and in most cases eliminated.

Preferably, the ground support cover is positioned over the joint between adjacent segments where the segment ends should be separated to expand the ring to support the complementary segment.

In one particular method, a ground support cover is provided for each ring to be assembled, and this ground support cover is left in place across the gap between the separated ends of the rings after the supplementary segment has been inserted.

In another method, the ground support cover comprises a portion of the shield that extends from the rear end of the shield and covers the area of the ring separating adjacent segments.

In any of the claims, the ring ″
When assembling the segments into the shield, the segments are loosely connected to each other, and after expansion of the rings and insertion of the complementary segments, the connection between the rings is finally tightened.

When the ring segments are assembled in the shield, they are loosely connected to the previously assembled ring segments and, after ring expansion and insertion of the supplementary segments described above, are connected to the newly assembled ring segments. Tighten the connections with previously assembled ring segments.

According to one method of the invention, the segments are connected to each other by bolts.

Other methods connect the segments to each other by radially extensible fasteners driven between overlapping hoops projecting from the edges of adjacent pairs of segments, and then expand the segments into hoops. Press and pull the ends of the segments together.

In yet another method, the edges of adjacent pairs of segments in each ring are adapted to mate with each other and create a radially self-supporting joint of the joint with respect to the axis of the ring of segments. It is best to be molded into

In any of the above methods, the adjacent ends of the ring segments are preferably formed to taper toward the rear end of the ring in the direction of driving the tunnel, and the complementary segment is formed using a tapered wedge key. After the shield is advanced and the rear end of the shield is engaged with the circumferential recess of the ring, the tapered wedge key is preferably driven between the pair of tapered ends.

More specifically, when assembling the ring, a tapered wedge key is partially inserted between the tapered ends of a pair of segments of the ring, and the shield is advanced so that the rear end of the shield enters the circumferential recess at the tip of the ring. After engagement, the tapered wedge key should be driven sufficiently deep between the tapered ends.

In another method according to the invention, the adjacent segments to be separated may have mutually parallel ends, and the supplementary segments inserted into the gap resulting from the separation have parallel ends that engage said ends. It is better to have edges.

In any of the above methods, the tunneling shield facilitates assembly of the partially assembled ring within the shield;
In addition, in order to facilitate advancing the shield so that the rear end of the shield engages with the circumferential recess at the tip of the ring, the wall thickness of the rear portion of the shield preferably decreases toward the rear end.

Some specific embodiments of the invention will now be described with reference to the accompanying drawings.

First, referring to Figures 1 and 2, an arc-shaped precast concrete tunnel lining segment) 1
A ring of zeros is shown.

Each of these lining segments is of the same form except for the uppermost pair of segments 10a, and the joints between adjacent segments of the ring are as described in GB 200493.
1 and 2131514, and are shown in FIGS. 4 and 5. This will be explained below with reference to FIGS. 4 and 5.

Adjacent axially extending end faces of the segments are separated by a bitumen packing, and each end face of the segment is formed with two semi-cylindrical recesses 12, which recesses are formed in the opposite segments. It extends partway along the end face from the inside of the end face in alignment with the corresponding recess. One recess in each end face projects spaced apart light steel hoops 13 embedded in the concrete and receives a single light steel hoop 14 projecting into the recess from the other segment. Retractable fasteners 15 are driven through the overlapping hoops to securely lock the segments together.

British Patent No. 2139 describes adjacent segments of adjacent rings.
They are secured together by the connecting structure described and shown in No. 268. This structure is schematically shown in FIG. 3 and will be briefly described below with reference to FIG. At the center of each segment is an axially extending bore 17 in which is provided an elongated bolt having a T-shaped head at one end and a counterbore at the edge of the segment at the other end. It's open. A washer and nut are positioned at the end of the bolt within the counterbore. The distal periphery of each segment in the driving direction of the tunnel lining has two spaced apart sockets 18, one on each side of the central bore of the segment, each of these sockets 18 being capable of supporting a bolt. The receiver can accept the T-shaped end of the
The bolt is locked into the socket by inserting the head into the socket and turning the head 90 degrees. As shown in FIG. 3, each ring of segments is assembled adjacent to the segments of the previously assembled ring, the joints of this ring being staggered with respect to the joints of the previously assembled ring; and aligning the bolt with the socket located on one side of the bolt of the previously assembled ring. The bolts are pressed to insert the bolt heads into the sockets of the previously assembled ring, and then the bolts are turned to lock into the sockets. It is a good idea to partially turn the nuts of the bolts at the exposed periphery of the newly assembled segment up, but do not fully tighten them at this stage.

Referring again to Figures 1 and 2, the outer surface of the segment has a narrow recess 20 around the leading edge of the ring that cooperates with the edge of the tunneling shield used in assembling the segment. It is formed to do so. The depth of this recess is approximately the same as the depth of the trailing edge of the shield.

The upper pair of segments 10a of the ring do not have hoop 7 mating bin connections between the remaining adjacent edges of the segments. Instead, these segments have plates 23 embedded in their ends (see Figure 6).
A pocket 24 is formed in the back of these plates. A key segment 25 is disposed between adjacent edges of the upper segment 10a in engagement with the end plate. This key segment, as can be seen in FIG. 7, is a concrete casting with parallel sides into which two spaced internally threaded pipes 26 are cast. This key segment is secured in place by a bolt 28 extending through the end plate of the upper segment and threaded into the opposite end of threaded tube 26.

When the ring of segments is first assembled, it will be seen that the upper edges of the upper segments 10a abut each other. These segments are separated by hydraulic jacks that engage pockets in the segments on the back of the end plate.

A plastic sheet 29 is placed in the gap between adjacent segments to support the ground of the tunnel wall separating the segments to receive the key. The outer edge of the upper end of the segment 10a has a recess 30 for receiving this plastic plate, and the depth of the key is such that when inserted, the outer surface of the key is flush with the bottom surface of the recess. It is. The width of the recess and the dimensions of the plastic plate are
When the segments are separated to receive the key, this plate extends sufficiently over the gap to the recess to provide adequate support for the tunnel wall above the gap between the segment ends.

The tunnel lining described above is assembled using a standard form tunneling shield modified by providing an extended rear skin. This rear skin is preferably made of higher quality copper than previously used, with the wall thickness reduced from the usual 28 mm to approximately 8-10 m.

The extended rear skin requires higher quality steel to compensate for the reduced wall thickness and exhibit adequate strength.

The illustrated structure has an extended rear portion with uniformly reduced wall thickness compared to the main portion of the shield. However, in an alternative configuration, the rear portion of the shield may be tapered such that the wall thickness decreases at the trailing edge.

The operating steps for assembling the ring are shown in FIGS. 9-13 and will be described below with reference to FIGS. 9-13. A ring of segments is assembled within the shield 40, with adjacent segments of the ring connected to each other except at the top of the ring and to the previously assembled ring as described above. At this stage, the ring is completely within the rear outer layer of the shield. A plastic plate 29 is then inserted over the joint of the upper end of the ring between adjacent top segments 102 as shown in FIG.
It will be seen that the outer surface of a is slightly below the inner surface of the rear outer layer. A conventional hydraulic ram incorporated within the shield is then used to advance the shield 40 until the trailing edge of the rear outer layer of the shield surrounds the outside of the leading edge of the newly assembled ring. It reaches and enters the recess 20. Next, there is a pocket 24 at the upper end of the segment) 10a.
Using a hydraulic jack located at Insert key segment 25. The plastic plate 29 completely covers the gap created between adjacent ends of the segments and prevents the tunnel lining from collapsing into this gap. The key segment is then bolted into place and the jacks removed. next,
The elastic reservoirs 15 between adjacent segments are driven in enough to lock the ends of the segments together, and then the nuts of the through bolts connecting the segments to the previously assembled ring are tightened to tighten the segments together. and securely locks onto the previously assembled ring. Subsequently, the hydraulic ram of the tunnel shield is retracted to leave the space in front of the last assembled ring ready to receive the next segment ring, as shown in FIG. Continue this operation for the length of the tunnel. As shown in the developed view of the tunnel lining shown in Figure 3, the joints in the rings made of segments are moved clockwise along the tunnel.
They are then alternately staggered in a counterclockwise direction so that the joints between the segments are not directly aligned. Because the ring of segments is expanded to engage the ground, no voids are left around the ring that need to be filled with grout.

Of course, many modifications can be made to the embodiments described above without departing from the scope of the invention.

For example, the upper segment 10a of each ring may be formed with an edge that tapers at the top of the ring to receive a tapered wedge key 25a, as shown in FIG. The tapered wedge key can then be driven between these edges to expand the lining. This key is then bolted in place to the end of segment IOa.

Instead of elastic fastening devices for connecting adjacent segments of each ring, conventional bolt fastenings can be used, as well as as described in British Patent Specification No. 2.004,931. , adjacent ring segments can be simply bolted together or connected by dowels.

In a still further development, the axially extending edges of adjacent segments of the ring are sufficient to prevent radial relative movement of the segments with respect to the axis of the tunnel and to prevent any movement between adjacent segments. Chained joints may be made such as semi-mating joints or nasoflu joints that do not even require direct mechanical interlocking.

In the case of tunnels driven into moist, loose ground, the trailing edge of the rear shield has a ring which engages the ring of the tunnel lining when it is assembled into the shield and which repels moisture or soil from the newly assembled lining. It is advisable to provide an annular seal to prevent ingress.

In a modification of the tunneling shield, a short cover plate is integrally formed with the trailing edge of the shield, and the cover plate connects the segments such that the segments should be separated to receive the key segment. extending rearwardly from the rear end of the shield to engage the shield. This shield cover plate is, of course, advanced with the shield after one ring of segments has been assembled and is ready to support the ground on the joint to be separated in the next ring.

[Brief explanation of drawings]

1 is an end view of a tunnel lining ring formed from arcuate segments during assembly using the method according to the invention; FIG. 2 is an end view of the ring on line A--A of FIG. 1; The figure is a developed view of the lining; Figures 4 and 5 are detailed views of the connection between adjacent segments of the ring; Figure 6 is a sectional view of the upper part of the ring showing the key segment inserted into the ring; FIG. 7 is a plan view of the key segment; FIG. 8 is a plan view of a modified example of the key segment; FIGS. 9 to 13 are diagrams showing operating steps in assembling a ring made of segments. 10... Lining segment 10a... Uppermost pair of segments 12... Concavity 13, 14... Hoop 15...
- Fastener 20... recess 25... key segment 26... female threaded pipe 28... bolt 29...
・Plastic thin plate 40...Tunnel excavation shield / 2 / Ada / λ and! ,”yt:; −y

Claims (1)

[Claims] 1. In a method of assembling a tunnel lining using a shield for tunnel excavation, a recess is formed on the outer periphery of the ring at the tip of the ring in the forward direction along the tunnel with the assembled ring made of segments. Assemble a ring consisting of segments, each segment having a recess on its outer periphery, within the shield, and advance the shield relative to the assembled ring until the rear end of the shield is located in the recess at the distal end of the ring; The ring is expanded and pressed against the tunnel by separating adjacent segments at at least one location around the ring, supporting the tunnel wall at that location against collapse, and inserting a supplementary segment between the adjacent segments. A method characterized by inserting and completing the ring. 2. Separate the ends of the segments to expand the ring and position the ground support cover at the joint between adjacent segments to expand the ring, thereby positioning the ground support cover in the gap until the complementary segment is positioned in place. 2. A method according to claim 1, characterized in that the tunnel wall is supported. 3. A ground support cover is provided for each ring to be assembled, and after inserting the supplementary segment, this cover remains in place across the gap between the separated ends of the rings. The method described in section. 4. The ground support cover consists of a part of the shield, and this part covers the part of the ring that protrudes from the rear end of the shield and separates adjacent segments, according to claim 2. Method described. 5. When assembling the ring segments into the shield,
Claim 1, characterized in that these segments are loosely connected to each other, and after expansion of the rings and insertion of said segments, the connection between the rings is finally tightened.
The method according to any one of Items 1 to 4. 6. When assembling the ring segments into the shield,
These segments are loosely connected to the previously assembled ring segments, and after ring expansion and insertion of said supplementary segments, the connections between the newly assembled ring segments and the previously assembled ring segments are tightened. A method according to any one of claims 1 to 5, characterized in that: 7. A method according to claims 1 to 6, characterized in that the segments are connected to each other by bolts. 8. Connecting the segments to each other by radially extensible fasteners driven between overlapping hoops projecting from the edges of their adjacent pairs, and then expanding and pressing the segments against the hoops. 7. A method according to claim 1, characterized in that the ends of the segments are stretched together. 9. The edges of adjacent pairs of segments in each ring are shaped to mate with each other to create a self-supporting joint radially relative to the axis of the ring of segments. A method according to any one of claims 1 to 4. 10. The ends of a pair of adjacent segments in the ring are formed to taper toward the rear end of the ring in the direction of driving the tunnel, and the supplementary segment consists of a tapered wedge key to advance the shield. After the rear end of the shield is engaged with the circumferential recess of the ring, the tapered wedge key is driven between the pair of tapered ends to expand the ring. 9
The method described in any of the paragraphs. 11. When assembling the ring, a tapered wedge key is partially inserted between a pair of tapered ends of the ring segments and the shield is advanced to engage the rear end of the shield into the circumferential recess in the tip of the ring. 11. The method of claim 10, further comprising driving the tapered wedge key sufficiently deep between the tapered ends. 12. The adjacent segments to be separated have ends parallel to each other, and the complementary segment inserted into the gap resulting from separation has parallel sides engaging said parallel ends. The method according to any one of claims 1 to 10, characterized in that: 13. A method according to claim 12, characterized in that the pair of segments are separated by a lifting device attached to them. 14. The tunneling shield is then designed to facilitate assembly of the partially assembled ring within the shield and to facilitate advancement of the shield to engage the rear end of the shield in the circumferential recess of the leading end of the ring. 14. A method according to any one of claims 1 to 13, characterized in that the wall thickness of the portion decreases toward its rear end.