JPH0631552B2 - Tunnel lining concrete placing method and its center - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for placing lining concrete on the inner wall surface of an excavated tunnel, and a centle used for the method.

(Prior Art) When placing a lining concrete in tunnel construction, conventionally, as shown in FIG. 7, enter into a tunnel C of a center (usually 9 m to 12 m long) B supported by a portal structure A. Set, placing concrete E in the space D between the center B and the tunnel C, training the concrete E, demolding the center B, moving the center B in the excavating direction of the tunnel C, setting the center B Is repeated.

When setting Centr B, part of the rear end of Centr B is lapped on the existing concrete that has been placed first,
The concrete to be poured next is flush with the existing concrete. However, when pouring concrete, a horizontal load (side pressure) as a fluid of concrete acts on the center B, and the side pressure pushes the center B inward, whereby the portal structure A is displaced inward. , Centle B is just that much (usually 6-10 mm
Displaced inward, and the cast concrete projects inward. Therefore, when the center is set in the next position and concrete is poured, the joint F of the concrete E is not finished flush as shown in Fig. 9, resulting in unevenness (misalignment), resulting in poor appearance. was there.

To eliminate the misalignment of the concrete joint F
This is important for improving the finish of tunnel construction and concrete lining. Conventionally, the following measures have been taken in order to prevent this misalignment.

(1) To make the gate structure A strong so that it is difficult to displace.

(2) An anchor G is embedded in the concrete to be placed first as shown in FIG. 10, and after the concrete is hardened, the anchor G is fixed to a fixture H provided at the end of the centle B, and the centle is fixed. Make B difficult to move.

(3) Concrete is cast into the floor I to solidify the floor I before the side wall of the tunnel is fixed, an anchor is installed on the floor I, the anchor is fixed to the center B, and the center B is displaced. Hard to do.

(4) Fix the lock bolt and the Centle B driven into the tunnel bedrock so that the Centle B is difficult to displace.

(Problems of the prior art) However, the method (1) has a problem that the cost of the gate-shaped structure increases and the displacement of the gate-shaped structure A decreases, but it is not a complete solution without mistake. It was

The above methods (2), (3) and (4) require the work of installing the anchor G or the lock bolt and fixing them to the center, and the positioning set of the anchor, the lock bolt and the center is very difficult, In addition, the longer the tunnel, the larger the number of anchors and lock bolts, which increases the cost.

(Object of the Invention) An object of the present invention is to prevent the gate-shaped structure from being displaced even when lateral pressure is applied to the centle at the time of concrete pouring, and thus the centle not to be displaced, so that no misalignment of the joint portion occurs. The purpose is to provide a lining concrete pouring method and its center.

(Means for Solving Problems) In the method for placing concrete in a tunnel lining according to claim 1 of the present invention, as shown in FIG. 1, the side wall centr 1 is rotatably attached by the upper centle 2 and the hinge 4. A tunnel lining concrete pouring is made such that the centle 6 in which each part of each portion is held by the gate type structure 5 is appropriately separated from the wall surface of the tunnel 7 so as to face each other, and the lining concrete is placed in the facing gap. In the method, the gate structure 5
As shown in the figure, more displacement (displacement up to the position of the imaginary line in Fig. 5) than the amount of displacement applied to the side wall center 1 at the time of pouring concrete, in advance in the same displacement direction, before pouring concrete It is characterized by being provided.

In the concrete lining concrete lining for tunnel lining according to claim 2 of the present invention, as shown in FIG. 1, the side wall center 1 is rotatably attached by the upper center 2 and the hinge 4, and the side wall center 1 is a gate type structure. 2 and 3 of the concrete lining concrete pouring center which is held by
As shown in the figure, a cantilever beam 9 is projected from the gate type structure 5 to the existing concrete side, and the pre-displacement imparting body 10 is attached to the cantilever beam 9.
One end of the displacement imparting body 1 is attached, and the other end of the displacement imparting body 10 is pressed against the finished finished concrete.
0 is a displacement greater than the displacement applied to the side wall center 1 at the time of concrete pouring to the gate-shaped structure 5 via the cantilever 9 in the direction in which the displacement occurs before concrete pouring.
It is characterized in that it is given in advance.

In the concrete lining concrete lining for tunnel lining according to claim 3 of the present invention, as shown in FIG. 1, the side wall center 1 is rotatably attached by the upper center 2 and the hinge 4, and the side wall center 1 is a gate type structure. As shown in FIG. 4, in the concrete laying concrete lining for the tunnel lining held by the high tension cable 12 on the leg portions 11 on both sides of the gate structure 5, as shown in FIG.
The tension is applied to the high-tensile cable 12 so that the gate-shaped structure 5 is applied with a displacement larger than the displacement applied to the center by concrete placing in the same displacement direction before concrete placing. It is characterized by being

(Operation) In the concrete pouring method of the present invention, after the heights of the top ends of the gate-shaped structure 5 and the center 6 are set, the preceding displacement is applied to the gate-shaped structure 5. The advance displacement is applied by, for example, the advance displacement applying body 10 in FIG. 1 or the high tension cable 12 and the tension applying body 13 in FIG.

When the preceding displacement imparting body 10 of FIG. 1 is used to impart the preceding displacement, the preceding displacement imparting body (for example, a jack) provided on the cantilever beam 9 extending from the gate-shaped structure 5 as shown in FIGS. 2 and 3. ) 10 is operated to push a loading board (hereinafter referred to as a gripper) 14 attached to the tip thereof against the side end portion of the existing concrete 15 shown in FIG. 3 to surely bring the left and right grippers 14 into contact with each other. Thereafter, the preceding displacement imparting body 10 uniformly applies a load to the left and right legs 11 of the portal structure 5 to take a reaction force, and the portal structure 5 is moved through the cantilever 9 as shown in FIG. Pre-displace inward.

In order to apply the preceding displacement by the high tension cable 12 and the tension applying body 13 of FIG. 4, the high tension cable 12 is pulled by the tension applying body 13 to displace the leg portion 11 of the portal structure 5 inward, and the desired position is obtained. When the cable 12 has been displaced, the cable 12 is fixed with a nut 16.

In either case, the amount of advance displacement to be applied varies depending on the rigidity and rigidity originally possessed by the portal structure 5, but is generally 10
It should be around mm.

Next, a turnbuckle, a jack, etc. provided between the displaced gate structure 5 and the side wall center 1
Extend (Fig. 3) and set the center 6 in place.

Here, when the compressive force applied to the existing concrete 15 through the gripper 14 is, for example, 20 tons,
200 if the area of the gripper 14 is 50 cm x 80 cm
00kg ÷ 50cm ÷ 80cm = 5kg / cm 2 , and the so fully fit below early strength to hold the side walls Sentoru no adverse effect on the existing concrete.

When placing concrete, the side wall Centr 1 is first loaded by the lateral pressure of the concrete,
The turnbuckle 30 installed between the gate type frame 5 and the gate type frame 5 is pushed, and the gate type frame 5 is pushed by the turnbuckle 30. In this case, the preceding displacement given to the gate type frame 5 in advance is At point A in FIG. 6, if the stress due to the lateral pressure of the poured concrete is point B in the same figure, the gate structure 5 will not be displaced unless the lateral pressure reaches point A.

It should be noted that although a slight displacement occurs in the side wall center 1 and the turnbuckle 30 due to the lateral pressure of the concrete, since the displacement amount is actually negligible, the side wall splicing between the existing concrete and the concrete to be placed next is performed. No misalignment of parts occurs.

(Embodiment) FIGS. 1 to 3 are explanatory views of an embodiment of the present invention. This is to apply the preceding displacement to the portal structure 5 by the preceding displacement imparting body 10.

In the figure, 1 is a side wall center, and 2 is an upper center.

Reference numeral 4 denotes a hinge that rotatably connects the side wall center 1 and the upper center 2.

Reference numeral 9 in FIGS. 1 to 3 denotes a cantilever beam, which is projected rearward from the portal structure 5. Reference numeral 10 in FIGS. 1 to 3 is a preceding displacement imparting body 10 attached to the cantilever beam 9, for which a jack, for example, is used. The preceding displacement imparting body 10 is such that the gripper 14 provided at the tip thereof is pressed against the existing concrete 15 as shown in FIG. 2 to impart the preceding displacement to the portal structure 5.

In addition, it is preferable that an elastic material such as a rubber plate, a plywood, or a vinyl plate is attached to the surface of the gripper 14 that contacts the existing concrete 15 so that a local load does not easily act on the concrete 15.

FIG. 4 is an explanatory view of another embodiment of the present invention. This is to apply the preceding displacement to the portal structure 5 by the high tension cable 12 and the tension applying body 13. Tensioner 1
For example, a hydraulic jack is used as 3.

Reference numeral 16 in FIG. 4 is a tightening nut for fixing the high-tensile cable 12 tightened by the tension applying body 13.

Reference numeral 20 in FIG. 4 denotes a roll mounted on the upper portion of the portal structure 5, which is used for hanging the high tension cable 12.

Reference numeral 21 in FIG. 4 is for locking the high-tensile cable 12 to the portal structure 5 so as not to come off from the portal structure 5.

(Effects of the Invention) The present invention has the following effects.

(1) According to the tunnel lining concrete pouring method of the present invention, the lateral pressure of concrete at the time of pouring concrete is absorbed by the portal structure 5 which has been displaced in advance, so that the side wall has misaligned joints. Good concrete lining can be obtained.

(2) The construction of the concrete for placing concrete in the tunnel lining according to claims 2 and 3 has a simple structure, and the preceding displacement is imparted only by operating the preceding displacement imparting body 10 or the high tension cable 12 and the tension imparting body 13. It can be handled easily. Moreover, since it is not necessary to drive an anchor or a lock bolt, the cost does not increase even if the tunnel length becomes long.

[Brief description of drawings]

FIG. 1 is a front explanatory view showing an example of a concrete pouring centle of the present invention, FIG. 2 is a side view of FIG. 1, and FIG.
FIG. 4 is a front view showing another example of the concrete placing centle of the present invention, FIG. 5 is an explanatory view of the preceding displacement of the present invention, and FIG. 6 is a drawing of the preceding displacement and stress. Explanatory diagram showing the relationship, FIG. 7 is a front explanatory diagram of a conventional concrete placing method, FIG. 8 is a plan explanatory diagram of the same placing method, and FIG. 9 is a lining formed by the conventional concrete placing method. FIG. 10 is an explanatory view of a misalignment of a side wall portion of concrete, and FIG. 10 is an explanatory view of an anchor portion of a conventional concrete placing method. 1 is a side wall 2 is an upper part 4 is a hinge 4 is a hinge 5 is a gate structure 6 is a center 7 is a tunnel 8 is a lining concrete 9 is a cantilever beam 10 is a preceding displacement imparting body 11 is a leg of a gate structure 12 is high Tension cable 13 is a tension applying body

Claims (3)

[Claims] 1. A side wall section 1 is rotatably attached to an upper section 2 and a hinge 4, and a section 6 having each section held by a gate structure 5 is opposed to a tunnel 7 while being appropriately separated. In a concrete lining concrete placing method in which lining concrete 8 is placed in the facing gap, in the gate type structure 5, a displacement larger than the amount of displacement applied to the side wall center 1 at the time of placing concrete, Before placing, in the direction of displacement,
A method for placing concrete in a tunnel lining, characterized in that it is given in advance. 2. A concrete pouring center for a tunnel in which a side wall center 1 is rotatably attached by an upper center 2 and a hinge 4, and the side wall 1 is held by a gate structure 5, wherein said gate structure is 5, a cantilever beam 9 is projected to the existing concrete side, one end of the preceding displacement imparting body 10 is attached to the cantilever beam 9, and the other end of the displacement imparting body 10 is pressed against the placed concrete. The displacement imparting body 10 causes a displacement larger than the displacement amount applied to the side wall center 1 at the time of concrete pouring to the gate structure 5 through the cantilever 9 in the direction in which the displacement occurs before concrete pouring. , A concrete lining concrete lining for tunnel lining characterized by being given in advance. 3. A concrete pouring center for a tunnel in which a side wall center 1 is rotatably mounted by an upper center 2 and a hinge 4, and the side wall 1 is held by a gate structure 5, wherein the gate structure is provided. Legs 11 on both sides of 5
A high tension cable 12 is stretched over the
Applying tension to 2 and pouring concrete into the gate structure 5
In the direction of displacement, a preload is applied to the gate-shaped structure 5 before the concrete is placed so that the gate-shaped structure 5 is subjected to the preceding displacement.