Method for evaluating and setting angle of invert and lining construction joint surface, and invert and lining construction joint structure

Abstract

To provide a method for evaluating and setting an angle of an invert and lining construction joint surface, which can ensure that an invert and lining construction joint structure having a construction joint surface with an angle range including horizontal, which can realize labor saving, has sufficient strength, and to provide an invert and lining construction joint structure.SOLUTION: A method for evaluating and setting an angle of an invert and lining construction joint surface includes a specimen production step for producing a first specimen which is a specimen having a joint surface in a direction perpendicular to its axis, and a second specimen which is a specimen having a joint surface in a direction other than the direction perpendicular to the axis, a strength test implementation step for conducting a strength test on each specimen, and an evaluation and setting step for comparing a first strength of the first specimen with a second strength of the second specimen, evaluating the angle of the joint surface 30 of the second specimen having a second strength equal to or greater than the first strength as an appropriate angle, and setting the angle of the joint surface 30 of an actual work within an angle range including the angle evaluated as the appropriate angle.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for evaluating and setting the angle of the joint surface between an invert and a lining, and to a joint structure between an invert and a lining. [Background technology]

[0002] Regarding the joints (or seams) between the invert and lining of mountain tunnels, the Standard Specifications for Tunnels [Mountain Construction Methods] and Commentary (established in 2016) state that "In order to be able to resist forces from below, such as plastic pressure, together with the lining, curves should be inserted so that the structure is designed to smoothly transmit cross-sectional forces and stresses, and it is desirable for the joints to be located as perpendicular as possible to the wall of the lining," and so, in principle, the joints of the invert must be located perpendicular to the axis. However, in this case, the joint surface will have a small radius curve and the finished surface will be steep, so the concrete is often poured using an upper formwork, which poses issues such as the tendency for water pockmarks, air pockmarks, sand streaks, etc. to form on the concrete surface. Furthermore, compaction causes the diagonally finished joint surfaces to collapse, necessitating manual shaping, which poses construction challenges in that it is time-consuming and labor-intensive, particularly when the lining is thick or the rebar is densely spaced.

[0003] For the above reasons, it is preferable to finish the joint surface between the invert and the lining horizontally or approximately horizontally, as this will lead to careful compaction to improve the quality of the concrete and to labor savings in manual molding, etc.

[0004] Incidentally, it is known that in general mountain tunnels, when a horizontal joint surface is set, the joint surface is often at an angle of about 45 degrees to 60 degrees with respect to the axis of the lining. Here, in this specification, the explanation is given assuming that the direction perpendicular to the axis of the lining is 90 degrees. Therefore, when the joint surface is 45 degrees, it means that it is at an angle of 45 degrees from the 90 degrees perpendicular to the axis, and when the joint surface is 60 degrees, it means that it is at an angle of 30 degrees from the 90 degrees perpendicular to the axis. According to previous research (Yanagishita Takei et al.: Study on the angle of lining concrete joints, 76th Annual Academic Conference of the Japan Society of Civil Engineers, VI-426, 2021), by conducting uniaxial compression tests while changing the angle of the joint between the invert and the lining, it has been reported that the peak strength and elastic modulus are independent of the angle of the joint. On the other hand, it is a fact that shear forces and bending moments act on the joint structure between the invert and the lining due to external forces such as earthquakes. Therefore, if it can be guaranteed that the invert and lining joint structure having a joint surface with an angle range including horizontal has sufficient strength, a desirable joint structure can be formed, in combination with the labor saving described above. Therefore, a method for evaluating and setting the angle of the joint surface between the invert and lining that can guarantee that the joint surface has sufficient strength is desired.

[0005] Here, Patent Document 1 proposes an invert concrete construction device that improves the quality of the finished invert concrete and increases the efficiency of invert concrete construction. This invert concrete construction device has a main body that includes an upper frame that extends in the tunnel axial direction and has a rectangular shape in a plan view, and legs that support the upper frame on the tunnel bottom, a leveling member that is arranged below the upper frame and levels the concrete supplied to the tunnel bottom, and a support that is placed on the tunnel bottom and supports the leveling member so that it can move in the tunnel axial direction. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-145648 A Summary of the Invention [Problem to be solved by the invention]

[0007] The angle of the joint surface between the invert and lining constructed by the invert concrete construction device described in Patent Document 1 is also perpendicular to the axis of the invert, as shown in Figure 3 thereof. Therefore, even when this construction device is applied, it is difficult to solve the above-mentioned problem, i.e., to reduce labor.

[0008] The present invention aims to provide a method for evaluating and setting the angle of the joint surface between an invert and a lining, which can ensure that the joint structure between an invert and a lining, which has a joint surface with an angle range including horizontal, capable of realizing labor savings, has sufficient strength, and an invert and lining joint structure. [Means for solving the problem]

[0009] In order to achieve the above object, one aspect of the method for evaluating and setting the angle of the joint surface between the invert and the lining according to the present invention is, A method for evaluating and setting the angle of the invert and lining joint surfaces of a tunnel, which evaluates the appropriateness of the angle of the invert and lining joint surfaces and sets the angle evaluated as appropriate as the angle of the joint surface of the actual construction, A test piece production process in which a plurality of test pieces having a joint surface at a predetermined angle with respect to the axial direction are produced, and among the plurality of test pieces, a test piece having a joint surface in a direction perpendicular to the axial direction is designated as a first test piece, and a test piece having a joint surface in a direction other than the axial direction is designated as a second test piece; A strength test implementation step of implementing a strength test on the plurality of test specimens; The method is characterized by having an evaluation and setting process for comparing the first strength of the first specimen and the second strength of the second specimen measured in the strength test, evaluating the angle of the joint surface of the second specimen having a second strength equal to or greater than the first strength as an appropriate angle, setting an angle range including the angle evaluated as the appropriate angle, and setting an angle within the angle range as the angle of the joint surface of the actual work.

[0010] According to this embodiment, a first specimen having a joint surface in a direction perpendicular to the axis and a second specimen having a joint surface in a direction other than perpendicular to the axis are produced, and strength tests are conducted on each specimen. The angle of the joint surface of the second specimen having a second strength equal to or greater than the first strength of the first specimen is evaluated as an appropriate angle, an angle range including the angle evaluated as the appropriate angle is set, and an angle within this angle range is set as the angle of the joint surface of the actual work, thereby ensuring that the joint structure between the invert (concrete) and the lining (concrete) having a joint surface within an angle range including horizontal, which can achieve labor savings, has sufficient strength. In other words, when the angle of the joint surface is set to an angle that can realize labor saving (an angle that is horizontal or approximately horizontal), it is possible to guarantee that the joint structure having the joint surface of this set angle has a strength equal to or greater than that of the joint structure having the joint surface angled in the direction perpendicular to the axis. Here, approximately horizontal means an angle range inclined by about 10 degrees from the horizontal.

[0011] Another aspect of the method for evaluating and setting the angle of the joint surface between the invert and the lining according to the present invention is The angle range of the joint surface between the invert and the lining set in the evaluation setting process is characterized by being in the range of 45 degrees to less than 90 degrees when the direction perpendicular to the axis is 90 degrees.

[0012] According to this embodiment, by setting the angle range of the joint surface between the invert and the lining in the evaluation and setting process to a range of 45 degrees to less than 90 degrees when the direction perpendicular to the axis is 90 degrees, a horizontal or approximately horizontal joint surface, as in typical mountain tunnels, can be achieved, thereby reducing the labor required for careful compaction and manual shaping, etc.

[0013] In another aspect of the method for evaluating and setting the angle of the joint surface between the invert and the lining according to the present invention, The strength test is characterized by being at least one of a uniaxial compression test, a single shear test, and a bending test.

[0014] According to this embodiment, the uniaxial compression test and bending test can be used to confirm the mechanical performance of axial compression and bending in the invert and lining joint structure, and the face shear test can be used to confirm the failure mode of the uniaxial compression test in the invert and lining joint structure.

[0015] Another aspect of the method for evaluating and setting the angle of the joint surface between the invert and the lining according to the present invention is The roughness of the joint surface during another construction is measured as a first roughness measurement value, and a roughness reference value, which is a reference value of the roughness of the joint surface, is set based on the first roughness measurement value. The specimen production process is characterized in that the roughness of the joint surface of the specimen is measured to obtain a second roughness measurement value, and it is confirmed that the second roughness measurement value satisfies the roughness standard value.

[0016] According to this embodiment, a roughness standard value, which is a reference value for roughness at a joint surface, is set based on a first roughness measurement value for the roughness at the joint surface during other construction work, and by confirming that a second roughness measurement value for the roughness of the joint surface of the test specimen satisfies the roughness standard value, a test specimen can be manufactured with a guaranteed minimum roughness that can guarantee strength, with respect to the roughness at the joint surface, which has a large impact on strength, and a strength test can be performed.

[0017] Another aspect of the method for evaluating and setting the angle of the joint surface between the invert and the lining according to the present invention is Further comprising a step of setting a reference joint surface treatment method for setting a reference joint surface treatment method for making the roughness of the joint surface satisfy the roughness reference value; The reference joint surface treatment method for both the production of the test specimen and the actual construction includes spraying a retarder onto the joint surface and then chipping the joint surface with high-pressure water.

[0018] According to this aspect, by setting a standard joint surface treatment method for making the roughness of the joint surface satisfy the roughness standard value, a joint surface for the invert and lining joint structure having the necessary strength in the actual construction can be constructed. In a specific form, a retarder is sprayed on the joint surface, and then the joint surface is chipped with high-pressure water, so that any worker can construct a joint surface that satisfies the roughness standard value.

[0019] In addition, one aspect of the invert and lining joint structure according to the present invention is, The angle of the joint surface between the invert and the lining is less than 90 degrees, which is the direction perpendicular to the axis of the invert, and is in the angle range of up to 45 degrees, and the angle range includes the horizontal direction, The roughness of the joint surface is characterized by satisfying a roughness standard value, which is a standard value for roughness of a joint surface that is set based on multiple joint surface treatment methods in other practical construction works.

[0020] According to this embodiment, the angle of the joint surface between the invert and the lining is less than 90 degrees, which is perpendicular to the axis of the invert, and is in an angle range of up to 45 degrees, which includes the horizontal direction, and the roughness of the joint surface satisfies the roughness standard value set based on multiple joint surface processing methods in other practical construction works.Therefore, a joint structure can be realized that has a joint surface with an angle range including the horizontal, which can realize labor savings, and has sufficient strength. Effect of the Invention

[0021] According to the method of evaluating and setting the angle of the joint surface between the invert and the lining, and the joint structure between the invert and the lining of the present invention, it is possible to ensure that the joint structure between the invert and the lining, which has a joint surface with an angle range including horizontal, which can achieve labor savings, has sufficient strength. [Brief description of the drawings]

[0022] [Figure 1A] FIG. 2 is a vertical cross-sectional view of an example of a joint structure between an invert and a lining according to an embodiment of the present invention. [Figure 1B] FIG. 1 is a vertical cross-sectional view of an example of a conventional invert and lining construction joint structure. [Diagram 2] 1 is a flowchart of an example of a method for evaluating and setting the angle of the joint surface between an invert and a lining according to an embodiment. [Diagram 3] 1 is a table for explaining an overview of specimens for various strength tests. [Figure 4] 1 is a table explaining the concrete mixes of specimens for various strength tests. [Diagram 5] This is a stress-strain curve in a uniaxial compression test. [Figure 6] 1 is a graph showing test results of a uniaxial compression test. [Figure 7] This figure shows the τ-σ relationship summarized based on the test results of a uniaxial compression test and a direct shear test. [Figure 8] 13 is a graph showing test results of a bending test. [Figure 9] FIG. 13 is a photograph of the test specimen after bending test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, a method for evaluating and setting the angle of the joint surface between the invert and the lining according to the embodiment and a joint structure between the invert and the lining will be described with reference to the attached drawings. Note that in this specification and the drawings, substantially the same components may be denoted by the same reference numerals to avoid redundant description.

[0024] [Method for evaluating and setting the angle of the joint surface between the invert and the lining according to the embodiment, and joint structure between the invert and the lining] A method for evaluating and setting the angle of the joint surface of the invert and the lining according to the embodiment and an example of the joint structure of the invert and the lining will be described with reference to Figs. 1 to 9. Here, Fig. 1A is a vertical cross-sectional view of an example of the joint structure of the invert and the lining according to the embodiment, and Fig. 1B is a vertical cross-sectional view of an example of a conventional joint structure of the invert and the lining. Fig. 2 is a flowchart of an example of the method for evaluating and setting the angle of the joint surface of the invert and the lining according to the embodiment.

[0025] The invert and lining joint structure 50 shown in Fig. 1A is a structure of the joint surface 30 (or joint) of the invert 10 constituting a mountain tunnel and the lining 20. The axial direction X1 of the invert 10 is curved, but in the joint structure 50, the angle of the joint surface 30 is set at an angle different from the axial direction orthogonal to the invert 10 in the invert 10, and the illustrated example is a horizontal plane.

[0026] The angle θ between the horizontal direction and the axis-perpendicular direction X2 at the intersection P of the joint surface 30 and the axis-perpendicular direction X1 is in the range of 45 degrees to less than 90 degrees (a range of less than the axis-perpendicular direction X2 and up to 45 degrees) when the axis-perpendicular direction X2 is 90 degrees. Here, the angle θ in the illustrated example is simulating about 60 degrees, which is inclined about 30 degrees from the axis-perpendicular direction X2.

[0027] As shown in Figure 1A, when the joint surface 30 is horizontal, the axial force N acting on the joint surface 30 from the invert 10 and the lining 20 acts in a direction inclined at an angle θ from the axis perpendicular direction X2. Therefore, compared to the case where the axial force N acts in a direction perpendicular to the axis perpendicular direction X2, it is unclear whether the invert 10 and the lining 20 act together to resist the external force acting, and therefore it is necessary to confirm the strength of the joint structure 50.

[0028] In the conventional joint structure 50' in Figure 1B, which is shown for comparison with the joint structure 50, a joint surface 30' is set in the direction X2 perpendicular to the axis of the invert 10', and therefore, the axial force N from the invert 10' and the lining 20' acts in a direction perpendicular to the joint surface 30', and the invert 10 and the lining 20 form a structure that can resist external forces acting together.

[0029] In the conventional joint structure 50' shown in Fig. 1B, the invert 10 and the lining 20 are integrated and can resist external forces, but the joint surface 30' has a small radius curve, and the finished surface is steep, so the concrete is often poured using an upper formwork, which creates problems such as water and air pockmarks on the concrete surface. Furthermore, the diagonally finished joint surface collapses when compacted, which requires manual shaping, which is time-consuming and labor-intensive, creating construction problems.

[0030] According to the joint structure 50 shown in Fig. 1A, the joint surface 30 is horizontal (or approximately horizontal), so these construction problems can be solved and labor can be saved. Therefore, an evaluation method that can guarantee that the joint structure 50 having such a horizontal joint surface 30 has sufficient strength will be described in detail below. Here, when a horizontal joint surface is set in a typical mountain tunnel, it is known that there are many cases in which the angle of the joint surface 30 (the angle of the joint surface 30 in the direction perpendicular to the axis) with respect to the axis (tangential direction) of the lining 20 or invert 10 is about 45 degrees to 60 degrees, and the angle of about 30 degrees in the illustrated example means that it is about 60 degrees with respect to the tangential direction.

[0031] As shown in Fig. 2, the method for evaluating and setting the angle of the invert and lining construction joint surface includes a roughness reference value setting step (step S10), a specimen production step (step S12), a strength test implementation step (step S14), an evaluation setting step (step S16), and a reference construction joint surface processing method setting step (step S18). Here, the order of each step can be in various forms, and for example, the reference construction joint surface processing method setting step may be performed prior to the specimen production step.

[0032] First, in the roughness standard value setting step (step S10), the roughness of the joint surface during past construction work (other construction work) is measured and set as a first roughness measurement value. Then, based on this first roughness measurement value, a roughness standard value, which is a standard value of the roughness of the joint surface 30, is set.

[0033] It is generally known that the greater the roughness of the joint surface 30, the greater the shear strength at the joint surface 30, depending on the processing method used. In other words, even if a strength test is performed in the strength test implementation process, if the roughness of the joint surface in the actual field is smaller than that during the test, it cannot be said that the actual structure has mechanical properties equivalent to those of the test results. Therefore, by quantitatively evaluating the roughness of the joint surface 30, the test results can be used as a control standard when applying them to the actual field.

[0034] As an example of a method for quantitatively evaluating the roughness of the joint surface 30, the uneven shape of the joint surface 30 is measured by a laser sensor (e.g., Lidar (Light Detection And Ranging)) and the roughness (center line average roughness Sa) is obtained from the obtained uneven shape by numerical processing. The roughness was evaluated using the center line average roughness Sa (called the arithmetic mean height Sa in ISO 25178), which is commonly used when evaluating surface roughness.

[0035] In setting the roughness standard value, we decided to apply the on-site measurements of the joint surface at two previous tunnel construction sites. In the results of these on-site measurements, the joint surface was manually finished at an angle, and there was a general waviness. Therefore, we organized it by the waviness-corrected average roughness Sa', which is the center line of the center line average roughness Sa mentioned above corrected by the waviness. As a result, Sa' was 1.08mm, 1.22mm, 1.36mm, 1.42mm, 1.54mm, 1.55mm, 1.87mm, and 1.88mm, and Sa' = 1.08mm to 1.88mm.

[0036] Based on these results, we decided to prepare specimens with Sa' of approximately 1.0 mm so that the unevenness of the joint surface would not cause any problems even if it was at the lowest limit on site during strength testing.

[0037] In addition, the roughness of the joint surface during a large number of other construction works may be measured as first roughness measurement values, and the roughness standard value may be set based on the large number of first roughness measurement values.

[0038] Next, in the specimen production process (step S12), a plurality of specimens each having a joint surface 30 at a predetermined angle with respect to the axial direction are produced, and among the plurality of specimens, a specimen having a joint surface 30 in a direction perpendicular to the axial direction (90 degree direction) is designated as a first specimen, and a specimen having a joint surface 30 in a direction other than the direction perpendicular to the axial direction is designated as a second specimen. In addition, when producing the specimens, the roughness of the joint surface 30 is measured to obtain a second roughness measurement value, and it is confirmed that the second roughness measurement value satisfies the roughness standard value.

[0039] As shown in Figure 3, the strength tests to which multiple specimens are applied are the uniaxial compression test, the direct shear test, and the bending test. Therefore, multiple specimens are produced for each strength test, as shown in Figure 3. More specifically, in order to understand the effect of the angle of the construction joint surface in each strength test, three patterns of the angle of the construction joint surface were set for each strength test.

[0040] In addition, in order to understand the effect of the maximum size of the coarse aggregate, specimens were produced with two different maximum sizes of coarse aggregate: 40 mm assuming no reinforcement, and 20 mm assuming reinforcement. Figure 4 shows the concrete mixes applied to each specimen.

[0041] After pouring the first layer, which simulated an invert, the test specimens were coated with 1 / 4 the standard amount of retarder, taking into consideration the actual conditions at the site, and the next day roughened using a high-pressure washer, and the second layer, which simulates a lining, was poured 8 days after pouring the first layer. Strength tests were conducted at an age of about 36 days for the first layer and about 28 days for the second layer, and the test specimens were sealed and cured at a constant temperature of 20°C.

[0042] The specimens used in the uniaxial compression tests were prepared by removing a core from a concrete block immediately before the test and molding the specimen so that the joint surface was at the center of the specimen.

[0043] Next, in the strength test implementation step (step S14), various strength tests are performed using a plurality of specimens prepared for each of the uniaxial compression test, the single shear test, and the bending test. Note that, in the strength test, at least one of the uniaxial compression test, the single shear test, and the bending test may be performed, and for example, only one type of strength test may be performed, but it is preferable to perform all three types of strength tests, for example, since the strength of the joint structure 50 can be specified with higher accuracy.

[0044] Next, the methods and results of various strength tests will be described with reference to Figs. 5 to 9. Fig. 5 shows a stress-strain curve in a uniaxial compression test, and Fig. 6 is a graph showing the test results of the uniaxial compression test. Fig. 7 shows the τ-σ relationship compiled based on the test results of the uniaxial compression test and the single shear test, and Fig. 8 is a graph showing the test results of the bending test. Furthermore, Fig. 9 is a photograph of the test specimen after the bending test.

[0045] As shown in the stress-strain curve in Figure 5, in the uniaxial compression test, the load was applied up to the peak strength, then unloaded, and then loaded again, thereby obtaining the post-peak (maximum stress when reloaded) in the strain-softening region.

[0046] From Figure 6, which shows the results of the uniaxial compression test for each case, it can be seen that there is no difference in compressive strength and post-peak due to the angle of the joint surface 30. Even when the angle of the joint surface was 45 degrees, there was no destruction along the joint surface, so it is considered that the effect on compressive strength and subsequent post-peak is small up to an angle of 45 degrees.

[0047] In addition, the results showed that the compressive strength and post-peak were both greater for the maximum coarse aggregate size of 20 mm compared to the maximum coarse aggregate size of 40 mm. One of the reasons for this is presumably that the proportion of the weak layer at the aggregate-cement interface within the fracture surface is greater for the maximum coarse aggregate size of 40 mm.

[0048] In addition, from the τ-σ relationship compiled from the uniaxial compression test and the direct shear test shown in Figure 7, all specimens in the direct shear test (●, ◯) failed along the joint surface. The failure criterion line at the joint surface is also shown in the figure.

[0049] The uniaxial compression test (▲, △) shows the results of decomposition by the angle of the joint surface. Since the uniaxial compression test led to failure in the area below the failure criterion line, it is presumed that the failure was not due to sliding at the joint surface, but due to compression.

[0050] Next, the bending test results shown in Figure 8 show that the smaller the angle of the joint, the more the bending strength tends to improve. As shown in Figure 9, when the joint angle was 90 degrees, all of the specimens broke at the joint, whereas when the joint angle was 50 degrees, six out of eight specimens broke at the base material, not at the joint. This shows that when only pure bending is applied, the smaller the angle of the joint with respect to the axis, the smaller the effect of the joint.

[0051] In the evaluation and setting process (step S16), the first strength of the first specimen (a specimen having a joint surface in a direction perpendicular to its axis) measured in the strength test is compared with the second strength of the second specimen (a specimen having a joint surface in a direction other than perpendicular to the axis), and the angle of the joint surface of the second specimen having a second strength equal to or greater than the first strength is evaluated as an appropriate angle, an angle range including the angle evaluated as the appropriate angle is set, and an angle within the angle range is set as the angle of the joint surface of the actual work.

[0052] In other words, by conducting uniaxial compression tests and bending tests with different angles of the joint surface relative to the lining axis, the mechanical performance of axial compression and bending of the joint surface was confirmed, and the failure mode of the uniaxial compression test was identified from the direct shear test. It was also confirmed that if the angle of the joint surface is 45 degrees or more (less than 90 degrees), the mechanical performance of axial compression and bending is equal to or better than that of the conventional case where the joint surface is at a 90 degree angle perpendicular to the lining axis.

[0053] Based on the above results, in the evaluation and setting process, the angle range of the joint surface 30 between the invert 10 and the lining 20 was set to be between 45 degrees and less than 90 degrees, when the direction perpendicular to the axis is set to 90 degrees.

[0054] Next, in the reference joint surface treatment method setting step (step S18), a reference joint surface treatment method is set so that the roughness of the joint surface 30 satisfies the roughness reference value.

[0055] Here, five test specimens measuring 150mm x 150mm x 530mm were produced using a mix equivalent to unreinforced invert.

[0056] Here, the treatment method in case 1 is a case where no retarder is used, the treatment method in case 2 is a case where only chipping is performed with a high washer (no retarder), and the treatment method in case 3 is a case where the retarder Lucasol C (manufactured by Sika Japan Co., Ltd.) is applied at 1 / 4 the standard amount (75 g / m 2 In case 4, the retarder Lucasol C is sprayed at 1 / 2 the standard amount (150 g / m) and then treated with a high-pressure washer. 2 In case 5, the retarder Lucasol C was sprayed at a standard amount (300 g / m 2 ) and then laitance treatment was performed with a high-pressure washer.

[0057] In cases 3 to 5, after concrete was poured and the bleeding water had settled, the retarder was sprayed with a spray bottle, and the laitance treatment was carried out with a high-pressure washer the next day. Regarding the method of spraying high-pressure water with the high-pressure washer, the treatment was insufficient with a distance of 10 cm from the high-pressure washer and one treatment, but the laitance was sufficiently removed with a second treatment. For this reason, the distance from the high-pressure washer was set to 10 cm, and the number of high-pressure water treatments was set to two. After the tests for all cases, the treatment status of the joint surface was visually judged, and the treatment method in case 3, which is closest to the actual joint condition on site, in which the retarder is sprayed in a standard amount x 1 / 4 and then high-pressure water treatment is carried out, can be set as the standard joint surface treatment method.

[0058] In this way, by evaluating and setting the angle of the joint surface between the invert and the lining, in which the angle of the joint surface 30 of the invert 10 is in the range of 45 degrees to less than 90 degrees and the joint surface is processed based on a standard joint surface processing method so that the roughness of the joint surface 30 satisfies the roughness standard value, it is possible to ensure that the invert and lining joint structure 50, which has a joint surface 30 with an angle range that includes horizontal, which can achieve labor savings, has sufficient strength.

[0059] In addition, the present invention is not limited to the configuration shown here, and may be implemented in other embodiments in which other components are combined with the configurations and the like of the above-mentioned embodiment. In this regard, the present invention may be modified within the scope of the gist of the present invention, and may be appropriately determined according to the application form. [Explanation of symbols]

[0060] 10: Invert 20: Lining 30: Joint surface (joint) 50: Invert and lining construction (construction joint) X1: Axial direction X2: Orthogonal to the axis

Claims

1. A method for evaluating and setting the angle of the invert and lining joint surfaces of a tunnel, which evaluates the appropriateness of the angle of the invert and lining joint surfaces and sets the angle evaluated as appropriate as the angle of the joint surface of the actual construction, A test piece production process in which a plurality of test pieces having joint surfaces at a predetermined angle with respect to the axial direction are produced, and among the plurality of test pieces, a test piece having a joint surface in a direction perpendicular to the axial direction is designated as a first test piece, and a test piece having a joint surface in a direction other than the direction perpendicular to the axial direction is designated as a second test piece; A strength test implementation step of implementing a strength test on the plurality of test specimens; a first strength of the first specimen and a second strength of the second specimen measured in the strength test, evaluating the angle of the joint surface of the second specimen having a second strength equal to or greater than the first strength as an appropriate angle, setting an angle range including the angle evaluated as the appropriate angle, and setting an angle within the angle range as the angle of the joint surface of the actual work.

2. A method for evaluating and setting the angle of the joint surface between the invert and the lining as described in claim 1, characterized in that the angle range of the joint surface between the invert and the lining set in the evaluation and setting process is in the range of 45 degrees to less than 90 degrees when the direction perpendicular to the axis is 90 degrees.

3. The method for evaluating and setting the angle of the joint surface between an invert and a lining as described in claim 1 or 2, characterized in that the strength test is at least one of a uniaxial compression test, a single shear test, and a bending test.

4. The roughness of the joint surface during another implementation work is measured as a first roughness measurement value, and a roughness reference value, which is a reference value of the roughness of the joint surface, is set based on the first roughness measurement value. The method for evaluating and setting the angle of the joint surface between an invert and a lining as described in claim 1, characterized in that in the specimen production process, the roughness of the joint surface of the specimen is measured to obtain a second roughness measurement value, and it is confirmed that the second roughness measurement value satisfies the roughness standard value.

5. Further comprising a step of setting a reference joint surface treatment method for setting a reference joint surface treatment method for making the roughness of the joint surface satisfy the roughness reference value; The method for evaluating and setting the angle of the joint surface between an invert and a lining as described in claim 4, characterized in that the reference joint surface treatment method for both the production of the test specimen and the actual construction includes spraying a retarder onto the joint surface and then chipping the joint surface with high-pressure water.

6. A joint structure between the invert and the lining, The angle of the joint surface between the invert and the lining is less than 90 degrees, which is the direction perpendicular to the axis of the invert, and is in the angle range of up to 45 degrees, and the angle range includes the horizontal direction; An invert and lining joint structure, characterized in that the roughness at the joint surface satisfies the roughness standard value, which is a standard value for roughness at the joint surface that is set based on multiple joint surface processing methods in other implemented construction works.

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