Pull-out test device and reinforced soil wall equipped with the pull-out test device

Abstract

To provide a pull-out test device and a reinforced soil wall equipped with the pull-out test device that can accurately diagnose the soundness of a grid-shaped reinforcing material embedded in an embankment structure after the construction of a reinforced soil wall with a double-wall structure. 【Solution means】A pull-out test device 10 comprising a guide pipe 11 having a full length that can be spanned and embedded between a retaining wall block 50 and an embankment structure 40, and a test reinforcing material 20 that can be embedded in the embankment structure 40. The rear end of the guide pipe 11 is sealed with a rear cap 13 with a slit, and the pull-out resistance of the fixed length portion 22 embedded in the embankment structure 40 through the test reinforcing material 20 is configured to be measurable.

Description

Technical Field

[0001] The present invention relates to a reinforced earth wall comprising an embankment structure hierarchically constructed and a plurality of retaining walls made of reinforcing blocks erected on the front side of the embankment structure, and particularly to a pull-out test device for evaluating the performance of the embankment structure and a reinforced earth wall equipped with the pull-out test device.

Background Art

[0002] As one type of reinforced earth wall, an Adem Wall (registered trademark) having a double-wall structure with an embankment structure as an inner wall and a retaining wall made of retaining wall blocks as an outer wall is known (Patent Documents 1 and 2). In the reinforced earth wall having a double-wall structure, the embankment structure as the inner wall is composed of a plurality of embankment layers and a mesh-shaped geogrid called an embankment reinforcing material. By embedding the embankment reinforcing material between each embankment layer, the shape retention of the embankment structure is maintained. Furthermore, by providing a space between the retaining wall as the outer wall and the embankment structure as the inner wall, the reinforced earth wall can be constructed without transmitting the deformation of the embankment structure during construction to the outer wall, and the space after the construction of the outer wall and the inner wall is filled with crushed stone to form a wall surface drainage layer.

[0003] When deformation such as bulging or forward collapse occurs on the retaining wall surface of the reinforced earth wall due to large-scale seismic motion, heavy rain, etc., the soundness of the embankment structure as the inner wall becomes a problem. It is considered that a major factor for the deformation to appear on the retaining wall surface of the reinforced earth wall after rainfall is that the water infiltrated into the inside of the embankment structure forms a water level on the bottom side of the embankment structure. This is because when a water level is formed inside the embankment structure, the frictional resistance between the grid-shaped embankment reinforcing material and the embankment material decreases, and the restraining force of the embankment material on the embankment reinforcing material decreases.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The reinforced earth wall with a double-wall structure encompasses the following problems. <1> As a means of grasping the soundness of the embankment structure, a method of actually measuring the pull-out resistance of the embankment reinforcement buried in the embankment structure is theoretically conceivable, but it is difficult to actually measure the pull-out resistance of the embankment reinforcement. <2> Therefore, in the reinforced earth wall with a double-wall structure, a technique that can accurately evaluate the pull-out resistance of the embankment reinforcement is desired.

[0006] The present invention has been made in view of the above points, and its object is to accurately diagnose (evaluate) the soundness of the grid-shaped reinforcement buried in the embankment structure, which is the inner wall after the construction of the reinforced earth wall with a double-wall structure, by a simple method, and to provide a pull-out test device and a reinforced earth wall equipped with the pull-out test device.

Means for Solving the Problems

[0007] The present invention presents a double-wall structure with an earth-retaining structure having a grid-shaped earth-retaining reinforcement buried between adjacent earth-fill layers one above the other as an inner wall and a retaining wall formed by stacking a plurality of retaining wall blocks as an outer wall. There is a space between the earth-retaining structure and the retaining wall, and there is a wall surface drainage layer formed by filling the space with crushed stones. It is a pull-out test device for a reinforced earth wall for evaluating the supporting force of the reinforcement buried in the earth-retaining structure, and includes a hollow-structured guide pipe that penetrates between the front and back of the retaining wall block, straddles the wall surface drainage layer, and has a full length that can be spanned between the retaining wall block and the earth-retaining structure and buried in the reinforced earth wall, and a test reinforcement having a full length that can be inserted into the guide pipe and presenting a strip shape that can be buried in the earth-retaining structure. The guide pipe is a flexible pipe body. The front end of the pipe body of the guide pipe is sealed with a front cap, and the rear end of the pipe body is sealed with a rear cap with a slit. The test reinforcement has a free length portion formed in the section accommodated in the guide pipe and a fixed length portion formed in the section extending outward from the guide pipe through the slit of the rear cap. The excess length portion formed at the front end of the free length portion of the test reinforcement accommodated in the guide pipe is configured to be pullable out of the guide pipe. , strip-shaped upper and lower seals are protruded on both the upper and lower sides of the slit opened in the rear cap, and the slit through which the test reinforcing material is inserted is sealed by the upper and lower seals done. In another aspect of the present invention, the test reinforcement is formed of the same material as the earth-retaining reinforcement. 。 This In another aspect of the invention, the upper seal and the lower seal are strip-shaped bodies that can be in contact with and sandwich the upper and lower side surfaces of the test reinforcement. Furthermore, the present invention is a reinforced earth wall having a double-wall structure with an earth-retaining structure having an earth-retaining reinforcement buried between upper and lower earth-fill layers as an inner wall and a retaining wall formed by stacking a plurality of retaining wall blocks as an outer wall. There is a space between the earth-retaining structure and the retaining wall, and there is a wall surface drainage layer formed by filling the space with crushed stones. It is equipped with a pull-out test device for evaluating the supporting force of the reinforcement buried in the earth-retaining structure. The pull-out test device is any one of the above-mentioned pull-out test devices. The pull-out test device is spanned and buried between the retaining wall block and the earth-retaining structure, and the fixed length portion of the test reinforcement constituting the pull-out test device is extended and buried in the earth-retaining structure, and it is configured to be able to measure the pull-out resistance of the fixed length portion buried in the earth-retaining structure through the test reinforcement. In another aspect of the present invention, a window hole is formed in a part of the retaining wall block, and the front end of the guide pipe is exposed to the front side of the retaining wall block in the window hole to install the pull-out test device.

Advantages of the Invention

[0008] The present invention has at least one of the following effects. <1> By using a simple-structured pull-out test device including a hollow-structured guide pipe and a test reinforcing material, it becomes possible to perform a pull-out test on the test reinforcing material previously embedded in the reinforced earth wall. Therefore, not only can the soundness of the test reinforcing material embedded in the embankment structure, which is the inner wall, be directly diagnosed (evaluated) without disassembling the reinforced earth wall having a double-wall structure, but also the soundness of the embankment reinforcing material and the embankment structure can be indirectly diagnosed (evaluated). <2> Since the guide pipe constituting the pull-out test device has flexibility, even when a displacement in the height direction occurs between the retaining wall, which is the outer wall, and the embankment structure, which is the inner wall, the free length portion of the test reinforcing material can follow this displacement together with the guide pipe. Therefore, it is possible to avoid an adverse effect on the pull-out resistance of the test reinforcing material. <3> By sandwiching the test reinforcing material with an upper seal and a lower seal protruding from the rear cap that seals the rear end of the guide pipe, the slit formed in the rear cap can be sealed. Therefore, even when the pull-out test device is embedded in the reinforced earth wall, it is possible to reliably prevent the surrounding earth and sand from flowing into the inside of the guide pipe and keep the environment for the pull-out test of the test reinforcing material in good condition. <4> During the construction of the reinforced earth wall, since it is only necessary to span and embed a small and lightweight pull-out test device between the retaining wall block and the embankment structure at an arbitrary height, the pull-out test device can be easily installed only by the labor of workers without using heavy machinery.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0010] 1. Reinforced soil wall as a premise With reference to the drawings, the double-wall structure reinforced soil wall 30 equipped with the pull-out test device 10 will be described hereinafter.

[0011] <1> Outline of the reinforced soil wall This will be described with reference to FIGS. 1 and 2. The reinforced soil wall 30 on which the present invention is premised has a double-wall structure with the embankment structure 40 as the inner wall and the retaining wall 55 made of retaining wall blocks 50 as the outer wall. In this example, a form in which a wall surface drainage layer 60 filled with single-sized crushed stones or the like is formed between the embankment structure 40 and the retaining wall 55 will be described.

[0012] <2> Embankment structure The embankment structure 40 includes a plurality of embankment layers 41 constructed in layers, a steel formwork 42 having a substantially L-shaped side cross-section installed on the front side of each embankment layer 41, and a plurality of embankment reinforcement materials 43 buried between each embankment layer 41.

[0013] <2.1> Steel formwork The steel formwork 42 is a slope forming member made of welded wire mesh for forming the front surface of each embankment layer 41. The steel formwork 42 has a substantially L-shaped side cross-section and has a horizontal portion and a vertical portion. If necessary, the steel formwork 42 may be a structure in which the horizontal portion and the vertical portion are connected by diagonal members for reinforcement.

[0014] <2.2> Embankment reinforcement material The embankment reinforcement material 43 is a grid-shaped reinforcement material for integrating a plurality of embankment layers 41 constructed in a hierarchical manner, and is horizontally buried between each embankment layer 41. As the embankment reinforcement material 43, known flexible materials such as geogrids and geotextiles can be used.

[0015] <3> Retaining wall The retaining wall 55 is a concrete wall erected so as to cover the front side of the embankment structure 40, and is composed of an aggregate of a plurality of retaining wall blocks 50.

[0016] <3.1> Retaining wall block The retaining wall block 50 is a concrete block formed into various shapes. The retaining wall block 50 in this example has a panel 51 having a square shape and one or a plurality of vertical strips 52 for connection integrally projecting from the back surface of the panel 51.

[0017] <3.1.1> Mooring hole The vertical strip 52 is provided with horizontal mooring holes 53 at multiple levels at intervals. The mooring hole 53 is a through hole for inserting a connection belt 45 described later, and is formed according to the mounting height of the connection belt 45.

[0018] <3.1.2> Window hole Most of the retaining wall blocks 50 have a non-porous structure in the panel 51, but the retaining wall block 50 where the pull-out test device 10 is planned to be installed is provided with a window hole 54 penetrating a part of the panel 51. The window hole 54 is an opening for inserting one end of a guide tube 11 constituting the pull-out test device 10.

[0019] In this example, a form in which the window hole 54 is formed in a circular shape is shown, but the window hole 54 may have any shape that allows one end of the guide tube 11 to be inserted. The formation position of the window hole 54 penetrating the panel 51 corresponds to the installation position of the pull-out test device 10.

[0020] <3.2> Connection belt Between the soil retaining structure 40 and the retaining wall block 50, they are connected using a connecting belt 45. The connecting belt 45 is inserted through the mooring holes 53 of the vertical strips 52 protruding from the back surface of the retaining wall block 50 and folded back, and the folded-back portions at both ends of the connecting belt 45 are connected to the soil retaining structure 40.

[0021] <3.2.1> Connecting means between the connecting belt and the soil retaining structure As the connecting means for the folded-back portion of the connecting belt 45, the folded-back portion of the connecting belt 45 is buried between the soil retaining layers 41 for connection, or the folded-back portion of the connecting belt 45 is connected to the front end of the soil retaining reinforcement 43 exposed on the front side of the soil retaining structure 40. In short, as long as the retaining wall block 50 can be supported on the back side of the block in a state where the reaction force of the connecting belt 45 is obtained by the soil retaining structure 40.

[0022] <4> Wall surface drainage layer The wall surface drainage layer 60 is an intermediate layer having a drainage function interposed between the retaining wall 55 and the soil retaining structure 40. As the wall surface drainage layer 60, for example, single-sized crushed stones or various granular artificial materials (such as sintered grains) can be used.

[0023] <5> Construction method of the reinforced soil wall The construction method of the reinforced soil wall 30 is well-known, but the construction method of the reinforced soil wall 30 will be briefly described hereinafter. That is, a step of constructing the soil retaining structure 40 by hierarchically constructing the soil retaining layer 41 while burying the soil retaining reinforcement 43 therein, a step of constructing the retaining wall 55 by stacking the retaining wall blocks 50 on the front side of the soil retaining layer 41, a step of connecting between the retaining wall block 50 and the soil retaining structure 40 via the connecting belt 45, and a step of constructing the wall surface drainage layer 60 by filling the space between the soil retaining layer 41 and the retaining wall block 50 with crushed stones or the like are appropriately combined to construct a reinforced soil wall 30 of a predetermined height.

[0024] In addition, in the step of constructing the soil retaining structure 40, it is advisable to install a formwork sheet 44 that restricts the permeation of soil particles inside the steel formwork 42 to enclose the front side of each soil retaining layer 41.

[0025] Further, the wall drainage layer 60 may be constructed not only in parallel with the construction of the embankment structure 40 but also after the completion of the embankment structure 40.

[0026] 2. Pull-out test device The pull-out test device 10 will be described with reference to FIGS. 1 to 3.

[0027] <1> Purpose of using the pull-out test device The pull-out test device 10 is a test device for diagnosing (evaluating) the soundness of the reinforced soil wall 30 having a double-wall structure. In other words, the pull-out test device 10 is a test device for diagnosing (evaluating) the soundness of the test reinforcing material 20 embedded in the embankment structure 40 which is the inner wall presenting a double-wall structure.

[0028] The soundness of the test reinforcing material 20 refers to the tensile strength or pull-out resistance of the test reinforcing material 20 in the state of being embedded in the embankment structure 40.

[0029] During a large-scale earthquake or heavy rain, the deformation of the exposed retaining wall 55 of the reinforced soil wall 30 can be confirmed visually, etc., but it is difficult to confirm the deformation of the inner embankment structure 40. For example, if a part of the reinforced soil wall is dug up and a pull-out test of the embankment reinforcing material 43 is performed, the soundness of the embankment reinforcing material 43 can be confirmed, but it is not practical to actually perform it. Therefore, in the present invention, by measuring the pull-out resistance of the test reinforcing material 20 using the pull-out test device 10, the pull-out performance (tensile performance) of the embankment reinforcing material 43 is indirectly evaluated, and finally the soundness (self-supporting property) of the entire reinforced soil wall 30 can be evaluated.

[0030] <2> Outline of the pull-out test device The pull-out test device 10 has a full length that can be spanned between the test reinforcing material 20 made of the same material as the embankment reinforcing material 43 and presenting a grid shape, a hollow guide tube 11 having a hollow structure into which the test reinforcing material 20 can be inserted and having a full length that can be spanned between a specific retaining wall block 50 and the front part of the embankment structure 40, a front cap 12 for sealing the front end opening of the guide tube 11, and a rear cap 13 for sealing the rear end opening of the guide tube 11.

[0031] <3>Reinforcement for testing The test reinforcement 20 is a strip-shaped test body. Since the test reinforcement 20 is used as a dummy member of the embankment reinforcement 43, it is made of a grid material (such as geogrid or geotextile) of the same material as the embankment reinforcement 43. The test reinforcement 20 is insertable into the guide pipe 11, and its overall length has a dimensional relationship longer than that of the guide pipe 11.

[0032] In the present invention, among the test reinforcement 20, the range inserted into the guide pipe 11 is defined as the free length portion 21, and the range protruding and exposed from the guide pipe 11 is defined as the fixed length portion 22 for explanation.

[0033] The overall length of the test reinforcement 20 can be appropriately selected according to the site, but in practical use, the width of the test reinforcement 20 may be 100 - 120 mm, and the overall length may be 2500 - 3500 mm.

[0034] <4>Guide pipe The guide pipe 11 is a flexible cylindrical body for guiding the test reinforcement 20 across the section between the retaining wall block 50 and the embankment structure 40. As the guide pipe 11, known resin corrugated pipes, dipolin pipes, etc. can be used. The flexibility is provided to the guide pipe 11 in order to avoid adverse effects on the test reinforcement 20 when the reinforced earth wall 30 is displaced.

[0035] <5>Front cap The front cap 12 is a lid with a non-porous structure for closing the front end opening of the guide pipe 11, and is detachable from the guide pipe 11.

[0036] <6>Rear cap The rear cap 13 is a lid for closing the rear end opening of the guide pipe 11, and has a horizontally long slit 13a at the center thereof, and a pair of upper seals 14 and lower seals 15 protruding in a strip shape on both sides of the slit 13a.

[0037] <6.1> Slit The slit 13a is formed to have a dimension through which the test reinforcing material 20 can be inserted, and the test reinforcing material 20 is inserted through the slit 13a into the rear cap 13.

[0038] <6.2> Upper and lower seals On the outer peripheral surface of the rear cap 13 formed with the slit 13a, an upper seal 14 and a lower seal 15 presenting a strip shape with the slit 13a interposed therebetween project rearward of the rear cap 13. The upper and lower seals 14, 15 function as a soil suction prevention material (seal member) that regulates the inflow of soil and the like into the guide pipe 11 through the slit 13a by contacting and sandwiching the upper and lower surfaces of the test reinforcing material 20 exposed from the guide pipe 11.

[0039] <6.2.1> Dimensions of the upper and lower seals The lateral widths of the upper and lower seals 14, 15 have dimensions that can cover in the transverse direction of the test reinforcing material 20.

[0040] The protruding lengths of the upper and lower seals 14, 15 may be the same dimension or may be set in different dimensional relationships.

[0041] When the protruding lengths of the upper and lower seals 14, 15 are in a combination of different dimensions, it is desirable that the upper seal 14 has a longer dimension than the lower seal 15. Practically, the total length of the upper seal 14 is 1000 - 1500 mm, and the total length of the lower seal 15 is 40 - 60 mm.

[0042] <6.3> Materials of the upper and lower seals The upper and lower seals 14, 15 may be formed of a combination of the same materials or a combination of different materials. When the upper and lower seals 14, 15 are composed of a combination of different materials, it is desirable that the lower seal 15 is formed of a hard material (such as a resin plate or a metal plate, etc.), while the upper seal 14 is formed of a soft material (such as a resin sheet or a civil engineering sheet, etc.). The upper seal 14 is formed of a soft material to prevent it from becoming a withdrawal resistance during the test of the test reinforcing material 20.

[0043] 3. Installation method of the pull-out test device When constructing the reinforced earth wall 30 in the above-described process, the pull-out test device 10 is buried and installed in the reinforced earth wall 30 in the following manner.

[0044] <1> Assembly of the pull-out test device In advance, while accommodating a part of the test reinforcing material 20 in the guide pipe 11, the front cap 12 and the rear cap 13 are attached to each open end of the guide pipe 11 to assemble the pull-out test device 10.

[0045] When attaching the rear cap 13 to the rear end of the guide pipe 11, the test reinforcing material 20 is inserted from the inside to the outside of the rear cap 13 through the slit 13a formed in the rear cap 13, and the test reinforcing material 20 is pulled out of the guide pipe 11.

[0046] After the front end portion of the test reinforcing material 20 is wound and accommodated in the guide pipe 11, the front cap 12 is attached and sealed. The reason for winding the front end portion of the test reinforcing material 20 and accommodating it in the guide pipe 11 is to form an extra length portion for pulling out the test reinforcing material 20 outside during the test of the pull-out test device 10. The length of the extra length portion that serves as the draw-out allowance of the test reinforcing material 20 is appropriately selected.

[0047] <2> Laying of the pull-out test device Next, the guide pipe 11 inserted into the window hole 54 of the retaining wall block 50 is horizontally laid, and the pull-out test device 10 is spanned between the retaining wall block 50 and the embankment layer 41.

[0048] When laying the guide pipe 11, by cutting it according to the shape of the guide pipe 11 on the vertical portion of the steel formwork 42, interference between the guide pipe 11 and the steel formwork 42 is avoided.

[0049] At this time, the fixing length portion 22 of the test reinforcing material 20 extending from the guide pipe 11 is laid while extending in the separation direction of the retaining wall block 50 on the upper surface of the embankment layer 41. The total length of the fixing length portion 22 of the test reinforcing material 20 can be appropriately selected.

[0050] In accordance with the embankment work of the reinforced earth wall 30, the embankment layer 41 and the wall surface drainage layer 60 are additionally provided on the back side of the retaining wall block 50, and the guide pipe 11 and the test reinforcing material 20 constituting the pull-out test device 10 are buried to complete the installation of the pull-out test device 10.

[0051] <3>Installation position of the pull-out test device The pull-out test device 10 is installed at an arbitrary position with respect to the horizontal direction or the height direction of the reinforced earth wall 30.

[0052] When water infiltrates into the embankment structure 40, the water is affected by gravity and flows into the lower part through the gaps between the soil particles, and it is easy to form a water level at the lower part of the embankment structure 40. Therefore, by burying the pull-out test device 10 at the lower part of the embankment structure 40, it becomes easier to detect the change in the pull-out resistance of the grid-shaped test reinforcing material 20 due to the infiltration of water.

[0053] <4>Pull-out resistance of the test reinforcing material The test reinforcing material 20 constituting the pull-out test device 10 is buried with its upper and lower surfaces sandwiched by the embankment layer 41. The same material as the embankment reinforcing material 43 is used for the test reinforcing material 20, and the same embedding conditions as the embankment reinforcing material 43 are set. Therefore, the pull-out resistance (support force) of the test reinforcing material 20 is the same as that of the embankment reinforcing material 43.

[0054] <5>Prevention effect of earth and sand suction When the pull-out test device 10 is buried in the ground, when only the slit 13a is provided in the rear cap 13, it is expected that earth and sand will flow into the guide pipe 11 through the slit 13a. By providing upper and lower seals 14, 15 around the slit 13a of the rear cap 13, the upper and lower seals 14, 15 sandwich the upper and lower surfaces of the test reinforcing material 20 while sealing the slit 13a, so that the inflow of earth and sand etc. directed into the guide pipe 11 can be effectively blocked.

[0055] <6>Influence of displacement of the reinforced earth wall on the test reinforcing material During a large-scale earthquake, differential settlement, heavy rain, etc., it is expected that displacement will occur between the double walls (retaining wall 55 or embankment structure 40) that make up the reinforced earth wall 30. Therefore, the influence of the displacement of the reinforced earth wall 30 on the free length portion 21 and the fixed length portion 22 of the test reinforcing material 20 will be described in detail.

[0056] <6.1>Influence on the free length portion of the test reinforcing material The free length portion 21 of the test reinforcing material 20 is isolated from the surrounding earth and sand etc. by the guide pipe 11 and is not directly affected by the displacement of the reinforced earth wall 30. Furthermore, when displacement occurs between the retaining wall 55 and the embankment structure 40, the free length portion 21 of the test reinforcing material 20 follows the displacement and deforms together with the guide pipe 11. Therefore, when displacement occurs between the retaining wall 55 and the embankment structure 40, excessive tensile force does not act on the free length portion 21 of the test reinforcing material 20. Therefore, the environment of the pull-out test of the test reinforcing material 20 can be kept good. Furthermore, since no tensile stress is generated in the free length portion 21 of the test reinforcing material 20, damage to the test reinforcing material 20 can also be avoided.

[0057] <6.2>Influence on the fixed length portion of the test reinforcing material The fixed length portion 22 of the test reinforcing material 20 is in the same embedding environment as the embankment reinforcing material 43. Therefore, when either the retaining wall 55 or the embankment structure 40 subsides, excessive tensile force does not act not only on the free length portion 21 but also on the fixed length portion 22 of the test reinforcing material 20.

[0058] Furthermore, when displacement occurs only inside the embankment structure 40, the fixed length portion 22 of the test reinforcing material 20 exhibits the same behavior as the embankment reinforcing material 43, and the pull-out resistance (support force) of the test reinforcing material 20 becomes the same as that of the embankment reinforcing material 43.

[0059] 4. Test Method of Pull-Out Test Device During a large-scale earthquake or differential settlement, etc., a pull-out test is conducted using the pull-out test device 10 to confirm the integrity of the grid-shaped reinforcing materials (test reinforcing material 20 and embankment reinforcing material 43) buried in the ground. The following describes the specific test method of the pull-out test device 10.

[0060] <1> Pulling out the excess length portion of the test reinforcing material Remove the front cap 12 exposed on the front side of the retaining wall block 50, and pull out the excess length portion at the front end of the test reinforcing material 20 housed in the guide pipe 11 to the outside.

[0061] <2> Pull-out test of the test reinforcing material Deploy a pull-out test facility on the front side of the retaining wall block 50 to conduct a pull-out test on the test reinforcing material 20.

[0062] <2.1> Deployment of the pull-out test facility For example, use a pull-out testing machine combined with a simple reaction frame, traction equipment such as a hydraulic jack, and a measuring instrument such as a load cell. Install a reaction frame on the front side of the retaining wall block 50, and connect the excess length portion of the test reinforcing material 20 to the pull-out testing machine mounted on the reaction frame.

[0063] <2.2> Pull-out test of the test reinforcing material Apply a pull-out force to the test reinforcing material 20 with the pull-out testing machine to measure the pull-out resistance of the fixed length portion 22. Since the embedding environment of the fixed length portion 22 of the test reinforcing material 20 and the embankment reinforcing material 43 is the same, the pull-out resistance (support force) of the test reinforcing material 20 can be regarded as the pull-out resistance (support force) of the embankment reinforcing material 43.

[0064] <2.3> Evaluation method for the integrity of the embankment reinforcing material Calculate in advance the pull-out strength of the test reinforcing material 20 or the embankment reinforcing material 43 embedded in the embankment structure 40 before displacement occurs under normal conditions.

[0065] Based on the pre-calculated pull-out strength under normal conditions, evaluate the soundness of the reinforced earth wall 30 after displacement by comparing the pull-out strength of the test reinforcing material 20 actually measured by a pull-out testing machine.

[0066] For example, if the measured value of the pull-out strength (pull-out resistance) of the test reinforcing material 20 actually measured by a pull-out testing machine exceeds the pull-out strength (pull-out resistance) assumed in the design of the reinforced earth wall, it can be interpreted that the embankment reinforcing material 43 has ensured the frictional resistance for the self-stabilization of the reinforced earth wall 30, and the soundness of the reinforced earth wall 30 can be indirectly evaluated.

[0067] For example, if the measured value of the pull-out strength of the test reinforcing material 20 actually measured by a pull-out testing machine (pull-out resistance) is lower than the pull-out strength (pull-out resistance) assumed in the design of the reinforced earth wall, it can be interpreted that the embankment reinforcing material 43 has not ensured the frictional resistance for the self-stabilization of the reinforced earth wall 30, and take appropriate reinforcement measures for the reinforced earth wall 30.

Explanation of symbols

[0068] 10 ···· Pull-out test device 11 ···· Guide pipe 12 ···· Front cap 13 ···· Rear cap 13a ··· Slit 14 ···· Upper seal 15 ···· Lower seal 20 ···· Test reinforcing material 21 ···· Free length part 22 ···· Fixed length part 30 ···· Reinforced earth wall 40 ···· Embankment structure 41 ···· Embankment layer 42 ···· Steel formwork 43 ···· Embankment reinforcing material 45 ···· Connecting belt 50 ···· Retaining Wall Block 51 ···· Panel 52 ···· Vertical Strip 53 ···· Mooring Hole 54 ···· Window Opening 55 ···· Retaining Wall 60 ···· Wall Surface Drainage Layer

Claims

1. A pull-out test device for reinforced soil walls has a double-wall structure with an inner wall being an embankment structure in which a grid-shaped embankment reinforcement material is buried between vertically adjacent embankment layers, and an outer wall being a retaining wall made of a plurality of stacked retaining wall blocks, and has a space between the embankment structure and the retaining wall, and a wall drainage layer formed by filling the space with crushed stone, and is used to evaluate the bearing capacity of the reinforcement material buried in the embankment structure, A guide pipe having a hollow structure that penetrates between the front and back surfaces of the retaining wall blocks, spans the wall surface drainage layer, and has a total length that allows it to be embedded in the reinforced soil wall between the retaining wall blocks and the embankment structure; A test reinforcement material having a total length capable of being inserted into the guide pipe and a strip-like shape capable of being embedded in the embankment structure, The guide tube is a flexible tube, The guide tube has a front end sealed with a front cap and a rear end sealed with a rear cap having a slit, The test reinforcement has a free length portion formed in a section accommodated in the guide tube and a fixed length portion formed in a section extending outward from the guide tube through a slit in the rear cap, The test reinforcement material is accommodated in the guide tube, and an excess length portion formed at a front end of the free length portion of the test reinforcement material is configured to be able to be pulled out to the outside of the guide tube, A band-shaped upper seal and a band-shaped lower seal are provided on both the upper and lower sides of the slit formed in the rear cap, The slit through which the test reinforcement material is inserted is sealed by the upper seal and the lower seal. Pull-out test device.

2. 2. The pull-out test device according to claim 1, wherein the test reinforcement material is made of the same material as the embankment reinforcement material.

3. 2. The pull-out test device according to claim 1, wherein the upper seal and the lower seal are strips that can be held by contacting the upper and lower side surfaces of the test reinforcement material.

4. A reinforced soil wall having a double wall structure with an inner wall being an embankment structure in which embankment reinforcement material is buried between upper and lower embankment layers, and an outer wall being a retaining wall made of a plurality of piled up retaining wall blocks, having a space between the embankment structure and the retaining wall, having a wall surface drainage layer formed by filling the space with crushed stone, and equipped with a pull-out test device for evaluating the bearing capacity of the reinforcement material buried in the embankment structure, The pull-out test apparatus is the pull-out test apparatus according to any one of claims 1 to 3, The pull-out test device is embedded between the retaining wall block and the embankment structure, The anchorage length portion of the test reinforcement material constituting the pull-out test device is extended and embedded in an embankment structure; The test reinforcement material is characterized in that it is configured to be able to measure the pull-out resistance of the anchorage length portion embedded in the embankment structure through the test reinforcement material. Reinforced earth wall equipped with pull-out test equipment.

5. A reinforced earth wall equipped with a pull-out test device as described in claim 4, characterized in that a window hole is opened in a part of the retaining wall block, and a pull-out test device is installed in the window hole with the front end of the guide pipe exposed to the front side of the retaining wall flock.

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