JPH0749760B2 - Shield for cast-in-place lining method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a primary lining in a conventional shield construction method,
In the lining method that directly implements the concrete lining method on the natural ground by omitting the steps such as secondary lining and back-filling injection, facilitating the attachment of the concrete core metal material, relocating the formwork, filling the tail void, and digging reaction force The present invention relates to a shield for a cast-in-place lining method in which support is automatically and surely performed to ensure work safety and labor saving.

(Prior Art) Conventional shield construction methods generally use segments,
The assembled segment is used as a reaction force of excavation, back-filling is injected into the space between the segment and the ground to prevent collapse of the ground, and the work process is divided like the concrete is rolled up as the next process, Also, since expensive segments are used, the construction cost is high and a long construction period is required.

In order to improve this work process, in recent years, a concrete cast-in-place lining method, in which the primary lining segment has been omitted, is being developed, but it requires a great deal of man-hours to move the formwork and attach the core material. However, back-filling injection is required as in the past.

In addition, a shield that can fully utilize the advantages of the cast-in-place lining method, such as leaving a problem in supporting the reaction force of the excavation, has not yet emerged.

(Problems to be solved by the invention) As described above, the shield construction method has advanced to the development of a cast-in-place lining construction method that does not use segments, but the following problems have not been solved and the advantages of the construction method can be fully utilized. It is a situation that cannot be done.

That is, (1) the transfer of the formwork is troublesome, and requires a lot of man-hours because it depends on the labor of the worker.

(2) Since concrete is condensed in the shield and tail seal, when the shield is advanced after condensation, a diameter difference between the outer diameter of the excavation and the outer diameter of the concrete lining is generated, and this gap is filled. is necessary.

(3) In order to guarantee the strength of the concrete, a core material is installed around the entire circumference in the form before pouring the concrete,
There is no suitable method because it is installed in a floating state,
A lot of man-hours are spent on manual work.

(4) Conventionally, when excavating the shield, the segment assembled to the rear is pressed to move it forward, but in the case of the cast-in-place lining method, it takes a considerable amount of time for the concrete to solidify. Will be prolonged.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a shield that can solve the above problems comprehensively and can fully utilize the advantages of the cast-in-place lining method.

(Means and Actions for Solving Problems) The present invention has been made in view of the above problems, in which the transfer of the formwork is changed to a simple mechanical system for forward and backward movement by a hydraulic jack, and when shield digging is performed. The gripper method is used to support the reaction force of the thrust on the strong existing concrete lining that has completed the rearward setting, and the concrete compaction jack and the shield jack are arranged in series so as to operate in mutually opposite extension directions, and inside the skin plate. By considering that the poured unconsolidated concrete is automatically flow-pressed into the tail void portion that occurs as the shield progresses, it is possible to omit the backfilling work into the tail void, and also the core material for reinforcing concrete. The holder provided with the core material and core support ring of the existing lining, the installation of which is exposed at the front end of the existing lining The structure ensures that concrete can be held until it solidifies by
It is possible to provide a shield that makes full use of the advantages of the cast-in-place lining method.

(Example) Next, the Example of this invention is described based on drawing.

1 (a) and 1 (b) are overall cross-sectional views of a shield for cast-in-place lining method, which is divided into right and left with XX as a boundary. The inner surface of the shield body is connected to the shield jack. An annular holder that slides in close contact with the holder, and a gripper connected to the holder so that it can be moved forward and backward through an inner mold that is engageable and releasable and an inner mold slide jack. The concrete placing pipe as a main component is a pipe for concrete injection fixed to the inner surface of the inner formwork, and is provided with an opening / closing valve.

One end of the inner formwork slide jack is connected to the inner formwork, behind which a concrete consolidation jack is arranged in series via a slidable intermediate support frame, and one end is connected to a gripper, The expansion and contraction forces of the mold slide jack and the concrete compaction jack are transmitted to the inner mold and the gripper, and the inner mold rolling preventer locks the rotation and slides.

The gripper body is an annular steel frame with the cross-sectional shape shown,
It consists of a shoe that is connected by a gripper jack, a wedge and a link, and is divided into several parts parallel to the tunnel axis. By expanding and contracting the gripper jack, the wedge surface of the wedge and the shoe causes the wedge action to press the inner surface of the lining to secure the gripper. Or it has a structure to cancel.

A seal is provided around the entire circumference of the holder to prevent unconsolidated concrete from flowing into the shield.

In addition, an annular core metal support ring (outer) and a core metal support ring (inner) for temporarily movably placing the front end of the core metal for the newly placed concrete lining
Are fixed by welding.

Further, between the holder and the shield body, there is provided a holder rolling prevention device which locks rotation and enables sliding.

An example of the work steps of the cast-in-place lining method constructed as described above is shown in FIGS. 2 (a), (b), (c), and (d).
It will be described based on.

FIG. 2 (a) shows that unconsolidated concrete is poured from a concrete casting pipe into a space A surrounded by the shield body, the inner peripheral surface of the skin plate, the inner formwork, the holder, and the end surface of the setting-completed lining. Indicates that

Since concrete is completely cut off from the ground, a homogeneous lining can be obtained without soil and sand flowing into the concrete.

In this state, the inner formwork slide jack is the smallest, the concrete consolidation jack is the most elongated, and the shield jack is the smallest.

Also, the holder and inner mold, inner mold slide jack,
The concrete compaction jack, the intermediate support frame and the gripper are connected as shown in FIG. 1, and the gripper operates the wedge by the gripper fixing cylinder to press and fix the shoe to the inner surface of the setting completion lining.

Also, the length L of the space A is the length of one ring of the lining l
Set slightly longer than.

That is, the length of L is increased by an amount commensurate with the volume where the skin plate thickness becomes a space (tail void) during the shield excavation.

That is, since the tail void is π / 4 (D ₃ ² −D ₂ ² ) × l, the volume of the A part is π / 4 (D ₂ ² −D ₁ ² ) × L = π / 4 (D ₃ ² −D ₂ ^2). ) L
+ Π / 4 (D ₂ ² −D ₁ ² ) l, and thus L = l × (2D ₃ ² −D ₂ ² −D ₁ ² ) / (D ₂ ² −D ₁ ² ) is obtained.

FIG. 2B shows the next step and shows a state in which one ring has been dug.

That is, while the shield jack is propelled by 1 stroke Lmm, the concrete consolidation jack is also reduced in synchronism with the shield jack and simultaneously moved so that the actual stroke is lmm.

(That is, the dimension in the longitudinal direction is reduced by S = L-1.) As a result, the previously set unconsolidated concrete is flowed and press-fitted into the tail void portion, and the shield is dug by 1 mm by 1 ring.

In this way, the flow of concrete and the amount of press-fitting are commensurate with the amount of tail voids, so the ground does not rise or sink.

FIG. 2 (c) shows the next step, in which the lock cylinder is actuated to release the connection between the holder and the inner mold to reduce the shield jack, and the holder also moves to the left as the shield jack shrinks. Indicates.

The pouring concrete is selected to have such a quality that it does not substantially flow during one stroke excavation time.

In this state, connect the rear end of the new concrete reinforcing metal core and the front end of the existing core metal with pins or bolts, and connect the front end of the new metal core support ring (outer)
, (Inside).

At this time, an extra space corresponding to the stroke length S of the concrete consolidation jack, S, is provided on the left side of the core metal support rings (outer) and (inner) so as not to hinder the forward movement of the core rod when the concrete consolidation jack extends. To

FIG. 2D shows the next step.

The inner mold slide jack is extended by the stroke L to advance the inner mold to the connecting position with the holder, and the lock cylinder is operated to couple the holder and the inner mold.

By returning to the process shown in FIG. 2 (a) and repeating this cycle, the in-situ lining is continuously performed and the excavation is continued.

(Effects of the Invention) Since the present invention is configured as described above in detail, the transfer of the formwork is performed by mechanical force, so that the work can be advanced in a short time without imposing a burden on the worker.

Also, the poured concrete is homogeneous because it flows, press fits, and is filled into the tail void portion as the required amount of material is poured into the tail void without coming into contact with the ground, and there is no problem such as uplift or depression of the ground. .

Furthermore, since the reaction force of the propulsion reaction is supported by pressing the gripper shoe against the inner surface of the lining that has completed setting, there is no possibility of causing a reaction force to act on the weak lining immediately after placing, so there is no risk of damage and the core metal for concrete reinforcement. The material can be easily connected to the existing core metal material by the support structure of the holder.

Further, according to the structure of the present invention, a system for automatically controlling the operation of each pressure jack can be incorporated for automation.

[Brief description of drawings]

1 (a) and 1 (b) are overall structural diagrams of an embodiment of the present invention, which are divided into left and right with XX as a boundary. 2 (a), (b), (c), and (d) are explanatory views of the working process of the present invention, and FIG. 3 shows a reference example of the prior art. 1 ... Shield jack, 2 ... Inner formwork 3 ... Concrete consolidation jack, 4 ... Gripper body 5 ... Gripper jack, 6 ... Wedge 7 ... Shoe, 8 ... Shield body 9 ... Concrete placing Tube, 10 ...... Lining 11 …… Core metal material, 12 …… Core material coupling bolt 13 …… Inner formwork slide jack, 14 …… Intermediate support frame 15 …… Holder, 16 …… Lock cylinder 20 …… Seal , 21 …… Body metal support ring (outer) 22 …… Body metal support ring (inner)

Claims (1)

[Claims] 1. In a cast-in-place lining method shield, an annular gripper is provided for fixing and supporting by pushing a reaction force from the inner surface of a strong lining that has completed the rearward condensation, and the shield jack and the concrete consolidation jack are connected in series. When the unconsolidated concrete placed in the skin plate comes into contact with the natural ground, the volume of the concrete compaction jack is reduced in synchronization with the shield jack when excavating. , It enables flow press-fitting so as to fill the tail void corresponding to the volume of the skin plate, is connected to the gripper mechanism, slides in the front-back direction by a hydraulic jack, forms a concrete placing frame in the forward position, and moves backward. And an annular ring that is arranged to provide space for the installation work of the concrete core metal A formwork was provided, which was also a member of the front end face of the lining in the form of an annular ring, and had a concrete core metal support ring, and the rear end was connected to the core metal of the existing lining. A shield for cast-in-place lining method, characterized in that a holder supporting the front end of the core material and capable of following the combined stroke of the shield jack and the concrete consolidation jack is connected to the end of the shield jack rod.