JP7588526B2 - Steel earth retaining panel and earth retaining structure using said steel earth retaining panel - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act. An explanation was given in the conference room of Kotsu Kensetsu Co., Ltd.'s Fuchu Branch on November 10, 2020.

Application of Article 30, Paragraph 2 of the Patent Act The construction method was carried out on January 25, 2021 near Shimojuku 2-553, Kiyose City, Tokyo.

The present invention relates to a steel retaining panel and a retaining structure using the steel retaining panel.

As disclosed in Patent Document 1, for example, there is a known earth retaining structure constructed by assembling corrugated steel plates in a vertical borehole formed by excavating the ground. The earth retaining structure is constructed by stacking structures formed by arranging multiple corrugated steel plates in a ring shape along the wall surface of the borehole in the axial direction of the hole.

As the depth of an earth-retaining structure increases, the earth pressure from the ground increases, and corrugated steel plates alone may not be strong enough. Also, as the depth in the axial direction of the hole increases, the weight of the structure placed above acts on the structure placed below. For this reason, in earth-retaining structures, in deeper areas, H-shaped steel called reinforcing rings are sandwiched between adjacent corrugated steel plates above and below to increase rigidity.

However, the construction of the reinforcing rings is complicated and time-consuming, which lengthens the construction period and increases the construction costs. Therefore, there is a demand for the construction of an earth retaining structure that can omit the reinforcing rings. For example, in shallow parts of a borehole where the earth pressure is small and a reinforcing ring is not necessary, a structure can be constructed by arranging multiple corrugated steel plates in a ring shape along the wall of the borehole, and in deep parts of a borehole where the earth pressure is large and a reinforcing ring is necessary, a structure can be constructed by arranging multiple steel earth retaining panels in a ring shape along the wall of the borehole. Steel earth retaining panels are products with higher rigidity than corrugated steel plates. The steel earth retaining panel includes a skin plate that faces the wall of the borehole, an upper main girder that is provided along the upper edge of the skin plate and forms the upper surface, a lower main girder that is provided along the lower edge of the skin plate and forms the lower surface, and joint plates that form both the left and right ends of the skin plate.

JP 2020-066845 A

The gap between the outer surface of the earth retaining structure and the excavation hole is filled with backfill injection material for the purpose of preventing the ground from loosening and subsidence. The backfill injection material is, for example, concrete or mortar. Since the corrugated steel plate has a corrugated cross section, it has a fixing allowance where the backfill injection material filled and hardened between the excavation hole and the corrugated steel plate can be caught. In other words, with the corrugated steel plate, the backfill injection material enters the recessed space of the corrugated cross section and hardens, and the hardened backfill injection material is caught in the recessed space, so the backfill injection material has high fixing ability. However, since the outer surface of the steel earth retaining panel is flat, there is no fixing allowance where the backfill injection material filled and hardened between the excavation hole and the steel earth retaining panel can be caught, and there was an issue with the fixing ability of the backfill injection material. If the backfill injection material is not sufficiently fixed to the earth retaining structure, there is an issue with the stability of the earth retaining structure.

The present invention aims to solve the above problems, and aims to provide a steel earth retaining panel and an earth retaining structure using said steel earth retaining panel that can improve the adhesion of the backfill injection material that is filled and hardened between the borehole and the earth retaining structure when constructing an earth retaining structure by arranging steel earth retaining panels in sequence along the circumferential direction of the wall surface of the borehole.

The steel earth retaining panel of the present invention is a steel earth retaining panel used to construct an earth retaining structure by being installed in a borehole formed by excavating the ground, and comprises a skin plate facing the wall surface of the borehole, an upper main girder arranged along the upper edge of the skin plate to form the upper surface, a lower main girder arranged along the lower edge of the skin plate to form the lower surface, and joint plates arranged on both left and right ends of the skin plate to form the left and right side surfaces, each of the upper main girder and the lower main girder being formed perpendicular to the hole axis direction of the borehole, each of the upper main girder and the lower main girder having a connecting hole formed therein, the connecting hole being arranged on the opposite side of the skin plate to the wall surface of the borehole, and the outer edge of either or both of the upper main girder and the lower main girder being arranged so as to protrude toward the wall surface of the borehole beyond the outer surface of the skin plate.

The retaining structure according to the present invention is constructed by installing multiple steel retaining panels in a borehole formed by excavating the ground, and the structure formed by arranging the multiple steel retaining panels along the wall surface of the borehole includes a first retaining structure section constructed in at least one stage in the axial direction of the borehole, and each of the multiple steel retaining panels constituting the structure has at least one of the steel retaining panels.

In the present invention, the outer edge of either or both of the upper and lower main girders is arranged to protrude toward the wall surface of the borehole beyond the outer surface of the skin plate, and a concave space can be formed between the protruding upper or lower main girders and the outer surface of the skin plate. This allows for a fixing space to be formed in which the backfill injection material that has been filled and hardened between the borehole and the steel retaining panel can be caught, thereby improving the fixing property of the backfill injection material and increasing the stability of the retaining structure.

1 is a perspective view showing a schematic view of an earth retaining structure according to a first embodiment of the present invention; FIG. 2 is a perspective view showing a liner plate as an example of a corrugated steel plate according to the first embodiment. FIG. 2 is a longitudinal cross-sectional view showing a liner plate as an example of a corrugated steel plate according to the first embodiment. FIG. 2 is a perspective view showing a plank plate as an example of a corrugated steel plate according to the first embodiment. FIG. 2 is a longitudinal sectional view showing a plank plate as an example of a corrugated steel plate according to the first embodiment. 1 is an oblique view showing a steel retaining panel according to embodiment 1. FIG. A cross-sectional plan view showing a steel retaining panel for embodiment 1. A front view showing a steel retaining panel for embodiment 1. A left side view showing a steel retaining panel for embodiment 1. FIG. 2 is an explanatory diagram showing a schematic example of a construction method for a retaining structure according to the first embodiment. A cross-sectional plan view showing an example of a first retaining structure portion in the retaining structure of embodiment 1. 2 is an enlarged schematic view showing a main part of the retaining structure according to the first embodiment. FIG. A cross-sectional plan view showing a modified example of the steel retaining panel of embodiment 1. This is a cross-sectional plan view showing an example of a first retaining structure portion in a retaining structure using the steel retaining panel shown in Figure 13. FIG. 15 is an enlarged view of part A shown in FIG. 14. FIG. 15 is an explanatory diagram showing a schematic diagram of the procedure for constructing the first retaining structure portion of the retaining structure shown in FIG. 14 . FIG. 15 is an explanatory diagram specifically showing the features of the construction method for the retaining structure shown in FIG. 14. 1 is a perspective view showing a schematic diagram of a modified example of the retaining structure according to the first embodiment; FIG. An oblique view showing a modified example of the steel retaining panel of embodiment 1. 13 is an enlarged schematic view showing a main part of the retaining structure of embodiment 2. FIG.

Below, an embodiment of the present invention will be described with reference to the drawings. In each drawing, the same or corresponding parts are given the same reference numerals, and their description will be omitted or simplified as appropriate. In addition, the shape, size, arrangement, etc. of the configurations shown in each drawing may be changed as appropriate within the scope of the present invention.

Embodiment 1.
A steel earth retaining panel 1 according to the first embodiment and an earth retaining structure 100 using the steel earth retaining panel 1 will be described with reference to Fig. 1 to Fig. 12. Fig. 1 is a perspective view showing a schematic view of the earth retaining structure according to the first embodiment.

As shown in FIG. 1, the earth retaining structure 100 is constructed by installing a corrugated steel plate 2 and a steel earth retaining panel 1 in a vertical borehole formed by excavating the ground. The earth retaining structure 100 is constructed when constructing a civil engineering structure such as a shaft for constructing the foundation of an architectural structure or a drainage well constructed underground. Specifically, the earth retaining structure 100 includes a second earth retaining structure portion 102 and a first earth retaining structure portion 101. The second earth retaining structure portion 102 is constructed by stacking four layers of structures 102A formed by arranging corrugated steel plates 2 in a circular arc shape in a planar view in a ring shape in the direction of the hole axis. The second earth retaining structure portion 102 is assembled by arranging the corrugated steel plates 2 in a staggered manner. The first earth retaining structure portion 101 is constructed by stacking two layers of structures 101A formed by arranging steel earth retaining panels 1 in a circular arc shape in a planar view in a ring shape in the direction of the hole axis. The first retaining structure 101 is also assembled by arranging the steel retaining panels 1 in a staggered pattern. As an example, the retaining structure 100 has a circular configuration when viewed from above. The number of stages of the first retaining structure 101 and the second retaining structure 102 is not limited to the configuration shown in the figure, and each may have at least one stage. Also, the number of corrugated steel plates 2 and steel retaining panels 1 in the circumferential direction of the retaining structure 100 shown in Figure 1 is an example and is not limited to this.

Figure 2 is a perspective view showing a liner plate as an example of a corrugated steel plate according to the first embodiment. Figure 3 is a vertical cross-sectional view showing a liner plate as an example of a corrugated steel plate according to the first embodiment. Figure 4 is a perspective view showing a plank plate as an example of a corrugated steel plate according to the first embodiment. Figure 5 is a vertical cross-sectional view showing a plank plate as an example of a corrugated steel plate according to the first embodiment.

The corrugated steel plate 2 is composed of, for example, a liner plate 2A shown in Figs. 2 and 3, or a plank plate 2B shown in Figs. 4 and 5. The liner plate 2A has a configuration in which the corrugated cross section is formed in a sine curve shape. The plank plate 2B has a configuration in which the corrugated cross section is formed in a rectangular shape. As shown in Figs. 2 to 5, the corrugated steel plate 2 has an arc-shaped circumferential flange portion 20 provided along the upper and lower edges, and an axial flange portion 21 provided along both ends in the arc direction. The circumferential flange portion 20 is formed by bending so as to protrude from the upper and lower edges of the corrugated steel plate 2 toward the inside of the drilling hole. The axial flange portion 21 is formed by welding a plate to both ends in the arc direction of the corrugated steel plate 2.

The corrugated steel plate 2 has a thickness of, for example, about 2.7 mm to 7 mm. In the retaining structure 100 shown in FIG. 1, the first and second stages from the top are made of corrugated steel plates 2 made of liner plates 2A, and the third and fourth stages from the top are made of corrugated steel plates 2 made of plank plates 2B. In the retaining structure 100, the earth pressure from the ground increases as the depth of the excavation hole increases, and the weight of the structure 102A arranged above acts on the structure 102A arranged below. For this reason, plank plates 2B, which are more rigid than the liner plates 2A, are used in the third and fourth stages of the retaining structure 100. Note that all stages of the second retaining structure 102 may be made of liner plates 2A, or all stages may be made of plank plates 2B.

The circumferential flange portion 20 has a plurality of connecting holes 20a formed along the arc direction for connecting adjacent corrugated steel plates 2 stacked in the hole axis direction, or connecting the corrugated steel plate 2 and the steel retaining panel 1. The vertically adjacent corrugated steel plates 2 are connected by butting the circumferential flange portions 20 together and fastening the shaft portions of bolts inserted into the connecting holes 20a with nuts, for example. The means for connecting the circumferential flange portions 20 of adjacent corrugated steel plates 2 may be, for example, a connector such as a clip. The number of connecting holes 20a shown in the figure is merely an example and is not limited to this.

The axial flange portion 21 has multiple connection holes 21a formed in the vertical direction to connect adjacent corrugated steel plates 2 arranged in the circumferential direction of the drilling hole. Adjacent corrugated steel plates 2 are connected by butting the axial flange portions 21 together and fastening the shaft portions of bolts inserted into the connection holes 21a with nuts, for example. The means for connecting the axial flange portions 21 of adjacent corrugated steel plates 2 may be, for example, a connector such as a clip. The number of connection holes 21a shown in the figure is an example and is not limited to this.

Figure 6 is a perspective view showing a steel earth retaining panel according to the first embodiment. Figure 7 is a cross-sectional plan view showing a steel earth retaining panel according to the first embodiment. Figure 8 is a front view showing a steel earth retaining panel according to the first embodiment. Figure 9 is a left side view showing a steel earth retaining panel according to the first embodiment.

As shown in Figures 6 to 9, the steel retaining panel 1 is provided with an arc-shaped skin plate 10 facing the wall of the borehole, an arc-shaped upper main girder 11 that is provided along the upper edge of the skin plate 10 and forms the upper surface, an arc-shaped lower main girder 12 that is provided along the lower edge of the skin plate 10 and forms the lower surface, and flat joint plates 13 that are provided at both ends of the arc direction of the skin plate 10 and form the left and right side surfaces, and is configured to be concavely formed opening toward the inside of the borehole. The skin plate 10, upper main girder 11, lower main girder 12, and joint plates 13 are each fixed by welding. The girder height of the upper main girder 11 and lower main girder 12 varies depending on the soil quality and depth of the borehole, but is, for example, about 150 mm to 400 mm. In addition, the height of the steel retaining panel 1 in the hole axis direction is designed to be in the range of 500 mm to 1000 mm, with 500 mm as the standard, taking into consideration the safety and efficiency of the workers constructing the retaining structure 100, for example.

The steel earth retaining panel 1 also has a shape retention member 14 that is disposed between the upper main girder 11 and the lower main girder 12 and that retains the shape of the steel earth retaining panel 1 during manufacture, transportation, and construction. The shape retention member 14 is composed of, for example, a plate-shaped member made of a steel plate or the like as shown in the figure, or a rod-shaped member made of a reinforcing bar or the like not shown in the figure. In the illustrated example, four shape retention members 14 are disposed at predetermined intervals in the arc direction. Note that the shape and number of shape retention members 14 are not limited to the illustrated example, and are determined taking into consideration, for example, the size and shape of the steel earth retaining panel 1, etc.

As shown in FIG. 9, the upper girder 11 is provided so that its outer edge 11a protrudes toward the wall of the borehole beyond the outer surface of the skin plate 10. The outer edge 11a here refers to the portion that protrudes toward the wall of the borehole beyond the outer surface of the skin plate 10. The lower girder 12 is also provided so that its outer edge 12a protrudes toward the wall of the borehole beyond the outer surface of the skin plate 10. The outer edge 12a here refers to the portion that protrudes toward the wall of the borehole beyond the outer surface of the skin plate 10. The protruding length of the outer edge 11a of the upper girder 11 and the outer edge 12a of the lower girder 12 is, for example, about 25 mm. The outer edge 11a of the upper girder 11 and the outer edge 12a of the lower girder 12 and the outer surface of the skin plate 10 form a concave space S into which the backfill injection material filled between the outer surface of the earth retaining structure 100 and the borehole enters.

As shown in FIG. 6, the upper main girder 11 has a plurality of connecting holes 11b for connecting adjacent steel retaining panels 1 stacked in the hole axis direction, or between the steel retaining panels 1 and the corrugated steel plate 2. The lower main girder 12 has a plurality of connecting holes 12b for connecting adjacent steel retaining panels 1 stacked in the hole axis direction. The adjacent steel retaining panels 1 are connected by butting one upper main girder 11 with the other lower main girder 12 and fastening the shanks of the bolts inserted in the connecting holes 11b and 12b with nuts. The adjacent steel retaining panels 1 and the corrugated steel plate 2 are connected by butting the upper main girder 11 with the circumferential flange portion 20 and fastening the shanks of the bolts inserted in the connecting holes 11b and 20a with nuts.

The diameter of the connecting hole 11b is preferably larger than the diameter of the connecting hole 20a. The structure 102A may have an error in roundness due to construction errors or low rigidity of the corrugated steel plate 2. If construction errors and roundness errors occur in the structure 102A, the positions of the connecting holes 11b and 20a may be slightly misaligned, making it difficult to insert bolts into the connecting holes 11b and 20a. In other words, by making the diameter of the connecting hole 11b larger than the diameter of the connecting hole 20a, the construction errors and roundness errors of the structure 102A formed by the corrugated steel plate 2 can be absorbed by the connecting hole 11b, and the bolts can be inserted into the connecting holes 11b and 20a. The position, size, and number of the connecting holes 11b are not limited to those shown in the figure, and may be appropriately changed and formed according to the shape and size of the steel retaining panel 1.

As shown in FIG. 6, the upper main girder 11 has a plurality of gouging holes 11c spaced apart in the arc direction for inserting a tool to gouge the upper main girder 11. As shown in FIG. 6 and FIG. 7, the lower main girder 12 has a plurality of gouging holes 12c spaced apart in the arc direction for inserting a tool to gouge the lower main girder 12. Gouging means, for example, inserting an object into a gap and twisting it. One example of a tool is a rod-shaped member such as a sino rod. The gouging holes 11c and 12c are provided to align the positions of the connecting holes 11b and 12b for connecting the steel retaining panels 1 adjacent to each other vertically, or the steel retaining panel 1 and the corrugated steel plate 2. The gouging holes 11c and 12c may be provided in only one of the upper main girder 11 and the lower main girder 12, or both may be omitted. Additionally, the positions, sizes, and numbers of the drilled holes 11c and 12c are not limited to those shown in the figure, and may be modified as appropriate.

The joint plate 13 has multiple connection holes 13a for connecting adjacent steel retaining panels 1 arranged circumferentially around the excavation hole. Adjacent steel retaining panels 1 are connected by butting the joint plates 13 together and fastening the shafts of the bolts inserted into the connection holes 13a with nuts. The number of connection holes 13a shown in the figure is an example and is not limited to this.

6 and 9, the left and right joint plates 13 are provided with gouging holes 13b for inserting a tool to gouge the holes. The tool is, for example, a rod-shaped member such as a sino rod. The gouging holes 13b are provided to align the positions of the connecting holes 13a of the steel retaining panels 1 adjacent to each other on the left and right. The gouging holes 13b may also be used to align the positions of the connecting holes 11b, 12b for connecting the steel retaining panels 1 adjacent to each other on the top and bottom, or the steel retaining panel 1 and the corrugated steel plate 2. The gouging holes 13b may be provided in only one of the left and right joint plates 13, or both may be omitted. The positions, sizes, and numbers of the gouging holes 13b are not limited to those shown in the drawings, and may be changed as appropriate.

Next, an example of a construction method for the retaining structure 100 will be described with reference to FIG. 10. FIG. 10 is an explanatory diagram that shows a schematic diagram of an example of a construction method for the retaining structure according to the first embodiment. In the construction method for the retaining structure 100 according to the first embodiment, after the second retaining structure part 102 is constructed, the first retaining structure part 101 is constructed below the second retaining structure part 102. First, as shown in FIG. 10(A), a borehole 201 for constructing the retaining structure 100 is formed in the ground 200. The borehole 201 is formed with an outer diameter, for example, 20 cm larger than the outer diameter of the retaining structure 100. The depth of the borehole 201 is, for example, about 0.5 m to 1.5 m. Then, the corrugated steel plate 2 is arranged in a ring shape along the wall surface of the borehole 201 to assemble the structure 102A.

The structure 102A is assembled by arranging the corrugated steel plates 2 in order along the circumferential direction of the wall surface of the borehole 201, and connecting adjacent corrugated steel plates 2 on the left and right with bolts and nuts. The corrugated steel plates 2 of the upper structure 102A and the corrugated steel plates 2 of the lower structure 102A are connected with bolts and nuts. The corrugated steel plates 2 of the upper and lower stages are arranged with their circumferential positions shifted so as to form a staggered arrangement. In this way, a part of the second retaining structure 102 is constructed by stacking the structures 102A in multiple stages (three stages in the illustrated example) along the hole axis direction.

Next, as shown in FIG. 10(B), the structure 102A located at the top is fixed to the ground 200 with a lattice 300, and then the excavated hole 201 outside the structure 102A is backfilled with excavated soil. Note that the means for fixing the structure 102A located at the top to the ground 200 is not limited to the lattice 300, and concrete may be used, for example.

As shown in FIG. 10(C), the ground is excavated while assembling the structures 102A and 101A to construct the second retaining structure 102 and the first retaining structure 101, and excavation is continued to a predetermined depth. After the structure 102A located at the top is fixed with the lattice 300, a corrugated steel plate 2 is placed at the bottom end of the structure 102A at the bottom along the circumferential direction of the wall surface of the excavation hole 201, and the corrugated steel plate 2 is connected to the corrugated steel plate 2 at the bottom with bolts and nuts, and adjacent corrugated steel plates 2 on the left and right are connected to each other with bolts and nuts to construct the structure 102A. In addition, concrete or mortar is filled between the corrugated steel plate 2 and the excavation hole 201 as a backfill injection material.

11 is a plan cross-sectional view showing an example of the first earth retaining structure in the earth retaining structure according to the first embodiment. The arrows in FIG. 11 indicate the range of each steel earth retaining panel 1. As shown in FIG. 10(C), the first earth retaining structure 101 is constructed at the lower end of the second earth retaining structure 102 after the second earth retaining structure 102 is constructed. As shown in FIG. 11, the structure 101A is assembled by sequentially arranging the steel earth retaining panels 1 along the circumferential direction of the wall surface of the borehole 201. The steel earth retaining panel 1 arranged on the wall surface of the borehole 201 is connected to the upper corrugated steel plate 2 or the upper steel earth retaining panel 1 with bolts and nuts, and is connected to the adjacent steel earth retaining panels 1 on the left and right with bolts and nuts. The upper corrugated steel plate 2 or the upper steel earth retaining panel 1 and the lower steel earth retaining panel 1 are arranged in a staggered manner in the circumferential direction. In this way, the first retaining structure 101 is constructed by stacking the structures 101A in multiple layers along the hole axis direction.

Figure 12 is an enlarged view showing a schematic diagram of the main parts of the retaining structure according to embodiment 1. As shown in Figure 12, a backfill injection material 202 is filled between the wall surface of the excavation hole 201 and the steel retaining panel 1 for the purpose of suppressing loosening and subsidence of the ground. The backfill injection material 202 is, for example, concrete or mortar. The backfill injection material 202 is injected through an injection port (not shown) formed in the steel retaining panel 1. The injection ports are formed with their position, size and number appropriately set according to the shape and size of the steel retaining panel 1. In the steel earth retaining panel 1 according to the first embodiment and the earth retaining structure 100 using the steel earth retaining panel 1, the outer edge 11a of the upper main girder 11 and the outer edge 12a of the lower main girder 12 are configured to protrude toward the wall surface of the excavation hole 201 beyond the outer surface of the skin plate 10, and a concave space S (see FIG. 9) is formed between the protruding upper main girder 11 and the lower main girder 12 and the outer surface of the skin plate 10. In other words, the steel earth retaining panel 1 can form a fixing margin on which the backfill injection material 202 filled and hardened between the wall surface of the excavation hole 201 and the steel earth retaining panel 1 can be caught by the concave space S, thereby improving the fixing property of the backfill injection material 202.

Although not shown in the figures, the steel retaining panel 1 may be configured so that the outer edge 11a or 12a of either the upper main girder 11 or the lower main girder 12 protrudes toward the wall surface of the excavation hole 201 beyond the outer surface of the skin plate 10. Even in this case, a concave space S is formed between the protruding upper main girder 11 or lower main girder 12 and the outer surface of the skin plate 10, so that a fixing space can be formed on which the backfill injection material 202 filled and hardened between the wall surface of the excavation hole 201 and the steel retaining panel 1 can be caught, thereby improving the fixing property of the backfill injection material 202.

The second retaining structure 102 is not limited to the four stages shown in the figure, and may have one or more stages. Each structure 101A constituting the first retaining structure 101 is not limited to the configuration formed by the six steel retaining panels 1 shown in the figure, and may be formed with a number other than six. The retaining structure 100 according to the first embodiment is not limited to a configuration having the second retaining structure 102 constructed with corrugated steel plates 2 and the first retaining structure 101 constructed with steel retaining panels 1, and although not shown in the figure, may be composed of only the first retaining structure 101 constructed with steel retaining panels 1.

Figure 13 is a plan cross-sectional view showing a modified example of the steel earth retaining panel according to the first embodiment. Figure 14 is a plan cross-sectional view showing an example of a first earth retaining structural part in an earth retaining structure using the steel earth retaining panel shown in Figure 13. Figure 15 is an enlarged view of part A shown in Figure 14. Figure 16 is an explanatory diagram showing a schematic diagram of the procedure for constructing the first earth retaining structural part of the earth retaining structure shown in Figure 14. Figure 17 is an explanatory diagram showing in detail the characteristics of the construction method of the earth retaining structure shown in Figure 14. The numbers in parentheses shown in Figures 16 and 17 indicate the numbers of the pieces of the steel earth retaining panel 1A.

As shown in FIG. 13, the steel earth retaining panel 1A may be configured such that the plan view is arc-shaped, and both end faces in the arc direction are inclined with respect to the radial direction of the excavation hole. Specifically, in the plan view, the steel earth retaining panel 1A has both end portions in the arc direction of the upper main girder 11 and the lower main girder 12, and the joint plate 13, in the steel earth retaining panel 1A. In other words, as shown in FIG. 14 and FIG. 15, in a structure 101A constructed by arranging a plurality of steel earth retaining panels 1A in a ring shape, the pair of end faces where the steel earth retaining panels 1A adjacent in the circumferential direction butt together are inclined with respect to the radial direction of the excavation hole. Note that inclination with respect to the radial direction of the excavation hole means that the steel earth retaining panel 1A to be installed last is inclined to such an extent that it can be slid circumferentially from the inside of the structure 101A into the space formed between the already installed left and right steel earth retaining panels 1A and 1A.

To construct an earth retaining structure using the steel earth retaining panels shown in FIG. 13, as shown in FIG. 16(A), the first to fifth pieces of steel earth retaining panels 1A are assembled in order along the circumferential direction of the wall surface of the excavation hole 201, leaving one sixth piece of steel earth retaining panel 1A, to construct a part of the structure 101A. The first to fifth pieces of steel earth retaining panels 1A are connected to the upper corrugated steel plate 2 or the upper steel earth retaining panel 1A with bolts and nuts, and adjacent steel earth retaining panels 1A on the left and right are connected to each other with bolts and nuts.

Then, as shown in FIG. 16(B), the remaining sixth piece of steel earth retaining panel 1A is inserted into the space S formed between the first piece of steel earth retaining panel 1A and the fifth piece of steel earth retaining panel 1A by sliding it circumferentially from the inside of the structure 101A. At this time, as shown in FIG. 17, one joint plate 13 of the sixth piece of steel earth retaining panel 1A is slid relative to one joint plate 13 of the fifth piece of steel earth retaining panel 1A. After one end of the sixth piece of steel earth retaining panel 1A is slid into the space S between the first piece of steel earth retaining panel 1A and the fifth piece of steel earth retaining panel 1A, as shown in FIG. 16(C) and FIG. 17, the other end of the sixth piece of steel earth retaining panel 1A is pushed from the inside of the structure 101A toward the outside (the direction of the arrow X in the figure) and fitted into the space S. The sixth piece of steel earth retaining panel 1A is then connected to the upper corrugated steel plate 2 or steel earth retaining panel 1A with bolts and nuts, and to the adjacent steel earth retaining panels 1A on the left and right with bolts and nuts. It is preferable that the sixth piece of steel earth retaining panel 1A, which is installed last, has a length in the arc direction shorter than the other steel earth retaining panels 1A, for example, by about 0 mm to 6 mm, and more preferably by about 3 mm. This is to make it easier to insert the sixth piece of steel earth retaining panel 1A into the space S and to improve the workability of assembly.

The steel earth retaining panel 1A shown in FIG. 13 and the earth retaining structure 100 using the steel earth retaining panel 1A have an arc shape in plan view, and both end faces in the arc direction are inclined relative to the radial direction of the excavation hole. This allows the last steel earth retaining panel 1A to be installed to be slid circumferentially from the inside of the structure 101A into the space S formed between the left and right steel earth retaining panels 1A already installed, improving workability.

The steel retaining panels 1A forming the structure 101A may be configured such that, as shown in FIG. 14, all of the pairs of end faces where adjacent steel retaining panels 1A in the circumferential direction butt together are inclined relative to the radial direction of the excavation hole, or, although not shown, at least one or more pairs may be configured to be inclined relative to the radial direction of the excavation hole.

Figure 18 is a perspective view showing a schematic modification of the retaining structure according to embodiment 1. Figure 19 is a perspective view showing a modification of the steel retaining panel according to embodiment 1.

The retaining structure 100 according to the first embodiment is not limited to the circular shape in plan view shown in FIG. 1. The retaining structure 100 may be constructed in a rectangular shape in plan view by installing a corrugated steel plate 2 and a steel retaining panel 1B in a vertical excavation hole formed by excavating the ground, as shown in FIG. 18. Specifically, the retaining structure 100 has a second retaining structure 102 constructed by stacking four structures 102A formed by arranging the corrugated steel plate 2 in a rectangular shape in plan view in the hole axis direction, and a first retaining structure 101 constructed by stacking two structures 101A formed by arranging the steel retaining panels 1B in a rectangular shape in plan view in the hole axis direction. The second retaining structure 102 is assembled by arranging the corrugated steel plate 2 in a staggered manner. The first retaining structure 101 is also assembled by arranging the steel retaining panels 1B in a staggered manner. The corrugated steel plate 2 shown in FIG. 18 uses the plank plate 2B shown in FIG. 4 and FIG. 5, but the liner plate 2A shown in FIG. 2 and FIG. 3 may also be used. The number of stages of the first retaining structure 101 and the second retaining structure 102 is not limited to the configuration shown in the figure, and each may have at least one stage. Also, the number of corrugated steel plates 2 and steel retaining panels 1B that make up each structure 102A and 101A shown in FIG. 18 is one example.

As shown in FIG. 19, the steel earth retaining panel 1B is provided with a flat skin plate 10 facing the wall of the excavation hole, a flat upper main girder 11 that is provided along the upper edge of the skin plate 10 and forms the upper surface, a flat lower main girder 12 that is provided along the lower edge of the skin plate 10 and forms the lower surface, and joint plates 13 that are provided on both the left and right ends of the skin plate 10 and form the left and right side surfaces, and is configured to be formed in a concave shape that opens toward the inside of the excavation hole. The skin plate 10, the upper main girder 11, the lower main girder 12, and the joint plates 13 are each fixed by welding. Although not shown enlarged, a corner steel earth retaining panel 1B processed into an L shape is placed at the rectangular corner of the first earth retaining structure part 101 shown in FIG. 18.

In this way, the retaining structure 100 according to the first embodiment can be constructed in various shapes by modifying the shape of the corrugated steel plate 2 and the steel retaining panel 1B. The retaining structure 100 is not limited to the circular shape shown in FIG. 1 and the rectangular shape shown in FIG. 18, but may be, for example, an oval shape like an oval coin in plan view, or a U-shape like a horseshoe. The corrugated steel plate 2 and the steel retaining panel 1B are configured in a shape that corresponds to the shape of the retaining structure 100.

Embodiment 2.
Next, a steel earth-retaining panel according to the second embodiment and an earth-retaining structure using the steel earth-retaining panel will be described based on Fig. 20 with reference to Figs. 1 to 19. Fig. 20 is an enlarged view showing a schematic view of a main part of the earth-retaining structure according to the second embodiment. Note that the same components as those in the first embodiment are given the same reference numerals and their description will be omitted as appropriate.

The steel retaining panel according to the second embodiment is characterized in that, as shown in FIG. 20, the outer surface facing the wall of the excavation hole 201 is provided with a protrusion 15 that protrudes toward the wall. The rest of the configuration of the steel retaining panel 1 is the same as that of the first embodiment.

The protrusion 15 shown in FIG. 20 is, for example, a steel plate, and is fixed to the outer surface of the skin plate 10 by welding. Note that the protrusion 15 is not limited to being fixed to the outer surface of the skin plate 10, but may also be fixed to the upper main girder 11, the lower main girder 12, or the joint plate 13. The protrusion 15 may be provided in multiple locations, not just one. The protrusion 15 is not limited to the steel plate shown in the figure, and other members such as square steel or H-shaped steel may be used as long as they can protrude toward the wall surface.

In the steel earth retaining panel 1 according to the second embodiment and the earth retaining structure 100 using the steel earth retaining panel 1, the outer edge 11a of the upper main girder 11 and the outer edge 12a of the lower main girder 12 are configured to protrude toward the wall surface of the excavation hole 201 beyond the outer surface of the skin plate 10, and a concave space S (see FIG. 9) is formed between the protruding upper main girder 11 and lower main girder 12 and the outer surface of the skin plate 10. In other words, the steel earth retaining panel 1 can form a fixing allowance for the backfill injection material 202 filled and hardened between the excavation hole 201 and the steel earth retaining panel 1 by the concave space S, thereby improving the fixing property of the backfill injection material 202.

In addition, the steel earth retaining panel 1 according to the second embodiment and the earth retaining structure 100 using the steel earth retaining panel 1 are provided with a protrusion 15 that protrudes toward the wall surface of the excavation hole 201 on the outer surface facing the wall surface of the excavation hole 201. Therefore, the steel earth retaining panel 1 can form a fixing space for the backfill injection material 202 that has been filled and hardened between the excavation hole 201 and the steel earth retaining panel 1 to be caught by the protrusion 15, thereby further improving the fixing property of the backfill injection material 202.

The steel earth retaining panel 1 and the earth retaining structure 100 have been described above based on the embodiment, but the steel earth retaining panel 1 and the earth retaining structure 100 are not limited to the configuration of the above-mentioned embodiment. For example, the construction method of the earth retaining structure 100 described based on FIG. 10 is one example and is not limited to the above-mentioned embodiment. In short, the steel earth retaining panel 1 and the earth retaining structure 100 include the range of design changes and application variations that are normally made by a person skilled in the art, within the scope that does not deviate from the technical concept.

1, 1A, 1B Steel retaining panel, 2 Corrugated steel plate, 2A Liner plate, 2B Plank plate, 10 Skin plate, 11 Upper main girder, 11a Outer edge, 11b Connection hole, 11c Drilled hole, 12 Lower main girder, 12a Outer edge, 12b Connection hole, 12c Drilled hole, 13 Joint plate, 13a Connection hole, 13b Drilled hole, 14 Shape retaining member, 15 Projection, 20 Circumferential flange, 20a Connection hole, 21 Axial flange, 21a Connection hole, 100 Retaining structure, 101 First retaining structure, 101A Structure, 102 Second retaining structure, 102A Structure, 200 Ground, 201 Excavation hole, 202 Backfill injection material, 300 Cross-shaped grid, S space.

Claims (5)

A steel earth retaining panel used to construct an earth retaining structure by being installed in a borehole formed by excavating the ground,
A skin plate facing the wall surface of the borehole;
An upper main girder provided along an upper edge of the skin plate to form an upper surface;
A lower main girder provided along a lower end edge of the skin plate to form a lower surface;
and joint plates provided at both left and right ends of the skin plate to form left and right side surfaces,
Each of the upper main girder and the lower main girder is formed perpendicular to the hole axis direction of the borehole,
A connecting hole is formed in each of the upper main beam and the lower main beam,
The connecting hole is provided on the opposite side of the skin plate from the wall surface of the borehole,
A steel retaining panel, wherein the outer edges of either one or both of the upper main girder and the lower main girder are arranged to protrude toward the wall surface of the excavation hole beyond the outer surface of the skin plate. A steel earth retaining panel used to construct an earth retaining structure by being installed in a borehole formed by excavating the ground,
A skin plate facing the wall surface of the borehole;
An upper main girder provided along an upper edge of the skin plate to form an upper surface;
A lower main girder provided along a lower end edge of the skin plate to form a lower surface;
and joint plates provided at both left and right ends of the skin plate to form left and right side surfaces,
A connecting hole is formed in each of the upper main beam and the lower main beam,
The connecting hole is provided on the opposite side of the skin plate from the wall surface of the borehole,
The outer edge of either one or both of the upper main girder and the lower main girder is provided so as to protrude toward the wall surface of the borehole beyond the outer surface of the skin plate,
A steel retaining panel further comprising a protrusion on an outer surface facing the wall of the borehole, the protrusion protruding toward the wall. A steel earth retaining panel used to construct an earth retaining structure by being installed in a borehole formed by excavating the ground,
A skin plate facing the wall surface of the borehole;
An upper main girder provided along an upper edge of the skin plate to form an upper surface;
A lower main girder provided along a lower end edge of the skin plate to form a lower surface;
and joint plates provided at both left and right ends of the skin plate to form left and right side surfaces,
A connecting hole is formed in each of the upper main beam and the lower main beam,
The connecting hole is provided on the opposite side of the skin plate from the wall surface of the borehole,
The outer edge of either one or both of the upper main girder and the lower main girder is provided so as to protrude toward the wall surface of the borehole beyond the outer surface of the skin plate,
A steel retaining panel further comprising a shape retention member provided between the upper main girder and the lower main girder to retain the shape. A retaining structure constructed by installing a plurality of steel retaining panels in a borehole formed by excavating the ground,
A structure formed by arranging a plurality of the steel earth retaining panels along the wall surface of the borehole includes a first earth retaining structure portion constructed in at least one stage in the hole axial direction;
A retaining structure, wherein each of the plurality of steel retaining panels constituting the structure has at least one steel retaining panel described in any one of claims 1 to 3. A structure formed by arranging a plurality of corrugated steel plates along the wall surface of the borehole further includes a second retaining structure constructed in at least one stage in the hole axial direction,
The earth retaining structure according to claim 4 , wherein the first earth retaining structural portion is constructed below the second earth retaining structural portion.

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