JP2018053449A - Construction method for spray lining concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method for spray lining concrete to make it possible to reduce dependence on an operator's sense as determining a thickness of concrete sprayed to precisely ensure the sprayed thickness compared with before and to perform the construction of spray lining concrete preferably.SOLUTION: This method includes a concrete spray construction step, at which concrete is sprayed to form a concrete spray lining construction area R by spraying concrete from one frame 2a (2) side toward the next frame 2b (2) side, a first piecework management step, at which a thickness of sprayed concrete at the side of the next frame 2b (2) is measured, and a second piecework management step, at which a thickness of sprayed concrete at the edge faces of both sides of the area R is measured.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for constructing spray lining concrete.

  Conventionally, in a mountain tunnel, for example, a natural ground is excavated by using a drill jumbo and the shear is sequentially discharged out of the tunnel well, and steel supporters are installed at a predetermined interval in the tunnel axial direction. Then, concrete is sprayed on the excavation surface of the natural ground, a rock bolt is placed in the natural ground, a waterproof sheet is laid, and a concrete lining of the secondary lining is constructed by using a centle (for example, patent Reference 1).

  On the other hand, there are cases where shotcrete is used for lining depending on the use and environment of the tunnel and the situation of natural ground.

  And when constructing such sprayed lining concrete, for example, after installing a steel support and performing primary spraying, the position corresponding to the construction span (tunnel axial direction of one casting length) The end frame of the end) is provided with a wife frame that protrudes from the inner surface of the primary spray to the inner side of the tunnel with a predetermined protrusion amount and is connected in the circumferential direction of the tunnel. And concrete is sprayed to the spray construction area (construction span) between the pair of frame frames installed at a predetermined interval in the tunnel axis direction, and the spray lining concrete is constructed.

JP 2011-26943 A

  However, in the conventional method for constructing sprayed lining concrete, the end frame position (end point position in the tunnel axis direction of one casting length) of the spraying construction area is used as a spray thickness index. In some cases, as the distance from the wife frame increases, the spray thickness tends to vary. That is, the spraying thickness is left to the operator's sense toward the center side of the construction area away from the wife frame.

  In order to achieve the above object, the present invention provides the following means.

  The method of constructing sprayed lining concrete according to the present invention is a method of spraying concrete on the inner surface of a tunnel and constructing sprayed lining concrete, with a predetermined interval in the tunnel axial direction, and a predetermined distance from the inner surface of the tunnel to the inner side. The frame is installed at a predetermined interval in the tunnel axis direction, and the concrete frame is installed between the adjacent frame frames in the tunnel axis direction. A concrete spraying process for constructing sprayed lining concrete, and concrete from one end frame to the other end frame that forms the sprayed construction area in the concrete spraying process In the first volume management process of measuring the spray thickness on the other wife frame side, and at the stage of spraying concrete on the spray construction area, Characterized in that it comprises a second volume control step of measuring the thickness of the end faces of concrete sprayed onto spray installation area.

  In this invention, when concrete is sprayed onto the spray construction area, the concrete is sprayed from one end frame to the other end frame that forms the spray installation area, and the first volume control process By measuring the spraying thickness of concrete on the other end frame side, it is possible to prevent the spraying thickness on the other end frame side from varying. Furthermore, by measuring the thickness of the end face of the concrete sprayed to the spraying construction area in the second volume management process, it is possible to prevent variations in the spraying thickness on both ends of the spraying construction area.

  In this way, by managing the spraying construction in the first volume management process and the second volume management process, it is less likely to leave the spraying thickness to the operator's sense, and the spraying thickness is more accurate than before. It is possible to secure and suitably apply the spray lining concrete.

  Moreover, in the construction method of the sprayed lining concrete of the present invention, at least the top end portion of the tunnel, the left and right arch shoulder portions, and the left and right arch portions in the first volume management step and the second volume management step It is desirable to measure the spraying thickness at the lower end of each and the left and right side walls.

  In this invention, when performing volume management in the first volume management process and the second volume management process, the top end of the tunnel, the left and right arch shoulders, the lower end of the left and right arch parts, and the left and right side walls By measuring the spraying thickness at at least seven locations in the circumferential direction of the tunnel, the spraying thickness can be more accurately ensured and the sprayed lining concrete can be suitably constructed. .

  Furthermore, in the construction method of the sprayed lining concrete of the present invention, the wire rod is stretched in the tunnel axial direction by connecting to the position of the design spraying thickness of the pair of adjacent end frames, and before the concrete spraying It is provided with a third volume control process for measuring the distance between the inner surface of the tunnel in the middle of the spraying construction area and the wire, and the concrete spraying process is performed by reflecting the measurement result of the third volume control process. desirable.

  In this invention, in the third volume management process, a wire rod such as a wire or water thread is connected to the position of the design spraying thickness of a pair of adjacent frame frames and stretched in the tunnel axial direction, before concrete spraying In addition, by measuring the distance between the inner surface of the tunnel in the middle of the spray construction area and the wire rod, the unevenness (uneven amount) on the inner surface of the tunnel in the middle of the spray construction area can be grasped. As a result, the wire thickness is used as an index, and the concrete spraying amount (position of the spraying surface) is adjusted according to the grasped unevenness of the tunnel inner surface, ensuring a more accurate spraying thickness and more suitable. It becomes possible to perform the construction of spray lining concrete.

  Further, in the method of constructing the spray lining concrete according to the present invention, an inspection hole is provided in the tunnel top end portion and the tunnel arch portion for each predetermined construction length set in advance, and the spray lining is performed at the inspection hole. It is further desirable to provide a fourth volume management process for measuring the thickness of the concrete.

  In this invention, in the fourth work volume management step, for each predetermined construction length set in advance, inspection holes are provided in the tunnel top and tunnel arches, and the thickness of the sprayed lining concrete is measured by these inspection holes. It is possible to confirm whether or not construction is suitably performed by measuring. As a result, it is possible to more reliably ensure the spraying thickness with high accuracy and to perform the sprayed lining concrete appropriately.

  In the method of constructing the spray lining concrete according to the present invention, it is less likely to leave the spray thickness to the operator's sense, ensuring the spray thickness more accurately than in the past, and preferably using the spray lining concrete. It becomes possible to perform construction.

It is a figure which shows the state which installed the wife frame in the construction method of the spraying lining concrete which concerns on one Embodiment of this invention. In the construction method of the spray lining concrete which concerns on one Embodiment of this invention, it is a figure which shows the state which sprayed concrete to the spray construction area | region between a pair of wife frames, and constructed the spray lining concrete. In the construction method of the spraying lining concrete which concerns on one Embodiment of this invention, it is the figure which showed an example of the measurement position of the spraying thickness of a tunnel circumferential direction. It is the figure which showed an example of the installation position of a test hole in the construction method of the spraying lining concrete which concerns on one Embodiment of this invention.

  Hereinafter, with reference to FIGS. 1-4, the construction method of the spray lining concrete which concerns on one Embodiment of this invention is demonstrated.

  Here, according to the use of the tunnel, the common environment, the condition of the natural ground, etc., this embodiment is suitable for managing the volume of sprayed lining concrete when constructing a tunnel by applying shotcrete as lining. It relates to a method for making it possible.

  Specifically, in the method for constructing sprayed lining concrete according to the present embodiment, as in the past, for example, primary spraying on the excavated ground surface, placement of rock bolts, etc. are performed to stabilize the natural ground. Then, as shown in FIG. 1, the frame 2 that protrudes inward from the tunnel inner surface 1 with a predetermined protrusion amount and is connected in the circumferential direction of the tunnel is installed at a predetermined interval in the tunnel axial direction (wife frame installation step). That is, the frame 2 is installed at a position corresponding to the construction span / spraying construction area R by projecting from the tunnel inner surface 1 such as the surface of primary spraying or the surface of steel support to the inside of the tunnel with a predetermined projection amount. .

  And as shown in FIG. 2, concrete is sprayed on the spray construction area | region R between a pair of adjacent wife frames 2 using this wife frame 2 as a parameter | index of spraying thickness, and sprayed lining concrete 3 (Concrete spraying process). At this time, in the present embodiment, concrete is sprayed from one end frame 2a (2) forming one spray construction region R toward the other end frame 2b (2), and one end frame 2a (2 ) To the other end frame 2b (2) so that the lining concrete 3 is formed sequentially in one direction in the tunnel axis direction.

  On the other hand, in the construction method of the sprayed lining concrete according to the present embodiment, the following method is used as the finished shape management of the sprayed lining concrete 3.

  First, as the first volume management (first volume management process), concrete is sprayed from one end frame 2a (2) forming the spray construction area R toward the other end frame 2b (2). The spray thickness is measured on the other end frame 2b (2) side (end point side of one casting length) to be sprayed.

  In addition, as the second volume management (second volume management process), the thickness of the end face of the concrete sprayed on the spray construction area R is measured at the stage where the concrete is sprayed on the spray construction area R.

  Further, in these first volume management and second volume management, as shown in FIG. 3, at least the top end T1 of the tunnel, the left and right arch shoulders T2 and T3, and the lower end of the left and right arches (arch) The spraying thickness is measured at T4 and T5 below the shoulder and T6 and T7 on the left and right side walls (such as near the spring line).

  Next, for example, when the unevenness (unevenness) of the tunnel inner surface 1 in the spray construction area T is large, third volume management (third volume management process) is performed as necessary. For this third volume management, wire rods such as ruler wires and water threads are stretched in the tunnel axis direction and connected to the position of the design spraying thickness of a pair of adjacent end frames 2 before concrete spraying. The distance between the tunnel inner surface 1 and the wire in the middle of the spray construction region R is measured. And concrete spraying construction is carried out reflecting the measurement result of this third volume management. That is, when the distance between the tunnel inner surface 1 and the wire is smaller than the design spraying thickness due to the unevenness of the tunnel inner surface 1, the concrete is sprayed to the tunnel inner side rather than the wire. .

  Even in this third volume management, at least the tunnel top end T1, the left and right arch shoulders T2 and T3, the left and right arch bottom ends T4 and T5, and the left and right side wall portions T6 and T7. It is desirable to measure the distance between the tunnel inner surface 1 and the wire at seven or more locations in the circumferential direction of the tunnel.

  Next, in the present embodiment, fourth volume management (fourth volume management process) is performed. In this fourth volume management, for example, as shown in FIG. 4, a measurement hole is provided in the tunnel top end T8 every construction length 40m, and a measurement hole is provided in the tunnel arch portions T9 and T10 every construction length 100m. The thickness of sprayed lining concrete is measured with these inspection holes. In addition, what is necessary is just to set the installation position of a test hole suitably according to a tunnel condition etc.

  And in the construction method of the spray lining concrete of this embodiment, by performing construction management as described above, it is less likely to leave the spray thickness to the operator's sense, and the spray thickness is more than conventional. Can be ensured with high accuracy, and the sprayed lining concrete 3 can be suitably constructed.

  That is, when concrete is sprayed onto the spray construction area R, the concrete is sprayed from one end frame 2a (2) forming the spray construction area R toward the other end frame 2b (2). In addition, by measuring the spraying thickness of the concrete on the other end frame 2b (2) side by the first volume control process, it is possible that the spraying thickness on the other end frame 2b (2) side varies. Can be suppressed. Furthermore, by measuring the thickness of the end face of the concrete sprayed to the spraying construction area R in the second volume management process, it is possible to suppress the occurrence of variation in the spraying thickness on both ends of the spraying construction area R. .

  In this way, by managing the spraying construction in the first volume management process and the second volume management process, it is less likely to leave the spraying thickness to the operator's sense, and the spraying thickness is more accurate than before. It is possible to secure and suitably construct the spray lining concrete 3.

  Also, when performing volume management in the first volume management process and the second volume management process, the tunnel top end, left and right arch shoulders, left and right arch lower ends, and left and right side wall tunnels By measuring the spray thickness at at least seven locations in the circumferential direction, the spray thickness can be more reliably ensured and the sprayed lining concrete 3 can be suitably constructed.

  Furthermore, in the third volume control process, wires such as wire and water thread are connected to the design spraying thickness positions of a pair of adjacent frames 2 and stretched in the tunnel axis direction. By measuring the distance between the tunnel inner surface 1 and the wire rod in the middle part of the spraying construction region R, the unevenness (unlanding amount) of the tunnel inner surface 1 in the middle part of the spraying construction region R can be grasped. Thereby, using the wire rod as an index, and adjusting the spraying amount of concrete (position of the spraying surface) according to the asperity of the tunnel inner surface 1 ascertained, the spraying thickness can be ensured more accurately and accurately. It becomes possible to perform the construction of the spray lining concrete 3 suitably.

  Also, in the fourth work volume management process, inspection holes are provided in the tunnel top and tunnel arches for each predetermined construction length set in advance, and the thickness of sprayed lining concrete 3 is measured using these inspection holes. By doing, it can be confirmed whether construction is being performed suitably. As a result, it is possible to more reliably secure the spraying thickness with high accuracy and to perform the construction of the sprayed lining concrete 3 appropriately.

  As mentioned above, although one Embodiment of the construction method of the spray lining concrete of this embodiment which concerns on this invention was described, this invention is not limited to said embodiment, In the range which does not deviate from the meaning, it is appropriate. It can be changed.

DESCRIPTION OF SYMBOLS 1 Tunnel inner surface 2 Wife frame 2a One wife frame 2b The other wife frame 3 Spraying lining concrete (spraying concrete)

Claims (4)

A method of spraying concrete on the inner surface of a tunnel and constructing sprayed lining concrete,
A tread frame installation step of setting a predetermined interval in the tunnel axis direction with a predetermined interval in the tunnel axis direction, and setting a predetermined interval in the tunnel axis direction that protrudes inward from the tunnel inner surface with a predetermined protrusion amount
A concrete spraying process in which concrete is sprayed onto a spraying construction area between a pair of adjacent frame frames in the tunnel axial direction to construct sprayed lining concrete,
And the first work volume which measures spraying thickness on the said other wife frame side while spraying concrete toward the other wife frame from one wife frame which forms the said spray construction area in a concrete spraying process Management process;
A spray lining concrete comprising a second volume control step of measuring a thickness of an end face of the concrete sprayed to the spraying construction area when the concrete is sprayed to the spraying construction area. Construction method. In the construction method of the spray lining concrete of Claim 1,
In the first volume management process and the second volume management process, at least the top of the tunnel, the left and right arch shoulders, the lower end of the left and right arch parts, and the right and left side wall parts are sprayed. A method of constructing sprayed lining concrete characterized by measuring. In the construction method of the spray lining concrete of Claim 1 or Claim 2,
The wire rod is stretched in the tunnel axial direction by connecting to the position of the design spraying thickness of the pair of adjacent frame frames, and the inner surface of the tunnel in the middle of the spray construction area is separated from the wire rod before spraying the concrete. A method for constructing sprayed lining concrete, comprising a third volume management process for measuring the concrete, and performing the concrete spraying process by reflecting the measurement result of the third volume management process. In the construction method of the spray lining concrete as described in any one of Claims 1-3,
For each predetermined construction length set in advance, it is provided with a fourth work volume management step in which inspection holes are provided in the tunnel top and tunnel arches, and the thickness of the sprayed lining concrete is measured by the inspection holes. A characteristic method of sprayed lining concrete.

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