Construction method of the perimeter slope of a landfill

Abstract

The present invention relates to a method for constructing a slope of a waste landfill, wherein a vertical cutoff wall is constructed in a landfill to be constructed on the original ground, and a first excavation section is excavated inside the vertical cutoff wall, thereby preventing the inner surface of the first excavation section from collapsing during the construction of the first excavation section. The method comprises: a vertical cutoff wall construction step (S1) in which a vertical excavation section is constructed in the weathered soil layer and weathered rock layer underground of the landfill to be constructed on the original ground, and a known vertical cutoff wall is constructed inside the vertical excavation section; and a first excavation section construction step (S2) in which a weathered soil layer above the original ground inside the vertical cutoff wall is excavated to a certain depth to excavate the first excavation section and a first perimeter layer protruding inwardly is formed around the lower perimeter of the first excavation section. A step (S3) of constructing a first soil homogenization layer, in which soil and cement are mixed in multiple layers, by embanking and compacting it in multiple layers on the inner side of the first excavation section, forming a first temporary slope extending upward from the inner side to the outer side on the inner side of the multi-layered first soil homogenization layer, cutting and leveling the inner side of the first temporary slope to form a vertical surface on the lower side of the inner side of the multi-layered first soil homogenization layer, and forming a first slope extending upward from the upper side of the vertical surface to the outer side, thereby constructing a first slope stabilization work on the inner side of the first excavation section; and a step (S4) of constructing a second excavation section by excavating the weathered soil layer in the inner lower part of the vertical surface down to the weathered rock layer, and forming a second perimeter layer protruding inwardly on the lower side of the second excavation section; A step (S5) of constructing a second soil homogenization layer mixed with soil and cement by embanking and compacting it in multiple layers on the inner side of the second excavation section and the inner side of the vertical plane, forming a second temporary slope extending upward from the bottom to the outside on the inner side of the multiple layers of the second soil homogenization layer, cutting and leveling the inner side of the second temporary slope to form an extended slope extending downward from the first slope on the inner side of the multiple layers of the second soil homogenization layer, forming a horizontal plane on the lower inner side of the extended slope, and forming a second slope extending downward on the lower inner side of the horizontal plane; and a second slope stabilization work.The method is characterized by including a third excavation section construction step (S6) of excavating the weathered rock layer in the inner lower part of the second slope to a certain depth to construct a third excavation section, and forming a third slope that is inclined to extend downward from the second slope on the inner side of the third excavation section.

Description

Technology Field

[0001] The present invention relates to a method for constructing a slope in a waste landfill, and more specifically, to a method for constructing a slope in a waste landfill by constructing a vertical cutoff wall in a landfill to be constructed on the original ground and then excavating a first excavation section inside the vertical cutoff wall, thereby preventing the first excavation section from collapsing during the construction of the first excavation section. Background Technology

[0002] Generally, waste landfills are sites for burying household waste generated during daily life and industrial waste from industrial sites; they are operated by public or private entities and vary in size depending on the volume of waste accepted.

[0003] Furthermore, the waste treatment method using 'landfill' involves excavating the project site to a planned depth, burying the waste starting from the bottom of the landfill facility, stacking the waste to a certain height on top of the accumulated waste, and repeating the process of covering the stacked waste with a barrier material (referred to as a 'covering layer') such as low-permeability soil, solidified materials, or soil recycled from construction waste, thereby allowing the waste to decompose naturally.

[0004] For example, when constructing a waste landfill underground to a depth of about 40m, construction is carried out from the top to the bottom. The excavation is performed in one go to a depth of 5 to 7m with the same slope gradient, and after forming a terrace of more than 2m, the process of excavating another 5 to 7m is repeated until the target underground excavation depth is reached.

[0005] In addition, the excavation of the waste landfill formed as described above involves forming slopes with different angles depending on the soil conditions at the project site, as shown in the attached drawing Fig. 8. This is because the degree of sliding that occurs varies depending on the angle of the slope formed, depending on whether the ground is weak, such as a landfill layer or a sedimentary layer, or strong, such as weathered soil or bedrock; therefore, the angle of the slope is formed differently to ensure safety.

[0006] However, as mentioned above, when forming slopes for landfills with different slope angles depending on the soil type, if the soil is a sedimentary layer or a landfill layer, the relatively projected excavation area—that is, the slope forming the slope—becomes wider. Conversely, although the length of the slope is formed longer and safer, it fails to reach the desired excavation depth, resulting in a shallow landfill depth corresponding to the landfill volume and a problem where the landfill volume is reduced.

[0007] Accordingly, in order to resolve the above-mentioned problems, the "Method for Forming a Slope of a Waste Landfill" of Korean Patent Registration No. 2503396, which was previously filed and registered by the applicant, is known.

[0008] A conventional method for creating a slope in a waste landfill is characterized by the following steps in order to control the landfill capacity of the waste landfill by adjusting the slope angle of the soil characteristics of the original ground to the slope angle of the landfill slope having the characteristics of bedrock: a temporary excavation process for excavating the original ground to have a certain depth and slope; a layer cutting process for forming stepped layers on the excavated slope; a compaction layer stacking process for adjusting the soil characteristics of the original ground to have the same soil characteristics as bedrock in the ground where the layer cutting process is completed, and compacting the adjusted soil to the height and width of each stepped groove to form a soil stabilization layer; and an angle adjustment process for increasing the landfill area by cutting and slicing the surface of a plurality of stacked compacted layers to form a slope having the same slope as a bedrock soil layer when the compaction layer stacking process is completed.

[0009] In addition, the conventional method for creating a slope of a waste landfill is characterized by further including a vertical cutoff wall installation process in which a vertical cutoff wall is constructed at a certain distance from the landfill excavation site prior to the temporary excavation process.

[0010] However, the conventional slope construction method for waste landfills described above involves constructing a vertical cutoff wall at a certain distance from the excavation site prior to the temporary excavation process. This method had a problem in that accidents frequently occurred where the slope formed around the temporary excavation area collapsed because the vertical cutoff wall became separated from the slope formed around the temporary excavation area during the temporary excavation process.

[0011] In addition, since the slope surface of the landfill, which is finally constructed using conventional slope construction methods, consists of soil, there was also a problem in that accidents of the landfill slope collapsing frequently occurred when it rained during the waste disposal process, as rainwater infiltrated the soil constituting the slope. Prior art literature

[0012] Republic of Korea Patent Registration No. 2503396. The problem to be solved

[0013] Accordingly, the present invention has been devised to resolve the aforementioned conventional problems, and the objective of the present invention is to provide a method for constructing a slope of a waste landfill that prevents the excavation surface of the first excavation section from collapsing during the construction of the first excavation section by constructing a vertical cutoff wall on a landfill site to be constructed on the original ground and then excavating a first excavation section inside the vertical cutoff wall.

[0014] Another objective of the present invention is to provide a method for constructing slopes in a waste landfill, wherein a water-blocking plate is placed on the surfaces of a first slope, an extended slope, a horizontal section, a second slope, and a third slope formed in the waste landfill to prevent rainwater from infiltrating the slopes of the landfill.

[0015] Another objective of the present invention is to provide a method for constructing slopes in a waste landfill that prevents the water barrier from sagging downward and peeling off after construction by connecting the upper end of the water barrier covering the surfaces of the first slope, the extended slope, the horizontal section, the second slope, and the third slope to the upper end of the vertical water barrier wall. means of solving the problem

[0016] The "method for constructing a slope of a waste landfill" of the present invention for achieving the above-mentioned purpose comprises: a vertical cutoff wall construction step (S1) in which a vertical excavation section is constructed in the weathered soil layer and weathered rock layer of the landfill to be constructed on the original ground, and a known vertical cutoff wall is constructed inside the vertical excavation section; and a first excavation section construction step (S2) in which a first excavation section is excavated by excavating the weathered soil layer above the original ground inside the vertical cutoff wall to a certain depth, and a first perimeter layer section protruding inwardly is formed at the bottom of the first excavation section. A step (S3) of constructing a first soil homogenization layer, in which soil and cement are mixed in multiple layers, by embanking and compacting it in the first excavation section, forming a first temporary slope extending upward from the lower inner side to the outer side around the inner perimeter of the first soil homogenization layer, cutting and leveling the inner surface of the first temporary slope to form a vertical surface at the lower inner side of the first soil homogenization layer, and forming a first slope extending upward from the upper side of the vertical surface to the outer side to construct a first slope stabilization work in the first excavation section; and a step (S4) of constructing a second excavation section by excavating the weathered soil layer at the inner lower side of the vertical surface down to the weathered rock layer, and forming a second perimeter layer protruding inwardly at the lower side of the second excavation section; The method is characterized by comprising: a step (S5) of constructing a second soil homogenization layer mixed with soil and cement by embanking and compacting it in multiple layers on the inner side of the excavation surface of the second excavation section and the vertical surface, forming a second temporary slope extending upward from the bottom to the outside on the inner side of the second soil homogenization layer in multiple layers, cutting and leveling the inner side of the second temporary slope to form an extension slope extending downward from the first slope on the inner side of the second soil homogenization layer in multiple layers, forming a horizontal surface on the lower inner side of the extension slope, and forming a second slope extending downward on the lower inner side of the horizontal surface; and a step (S6) of constructing a third excavation section by excavating the weathered rock layer in the inner lower part of the second slope to a certain depth, and forming a third slope extending downward from the second slope on the inner side of the third excavation section. Effects of the invention

[0017] The present invention, configured as described above, has the effect of providing a method for constructing a slope of a waste landfill with improved safety during construction, which prevents safety accidents by preventing the collapse of the excavation surface during the construction of the first excavation section, by constructing a vertical cutoff wall on a landfill to be constructed on the original ground and then excavating a first excavation section inside the vertical cutoff wall.

[0018] In addition, the present invention has the effect of preventing the slopes of a landfill from collapsing due to rainwater infiltration during the process of burying waste after construction, by covering the surfaces of the first slope, extended slope, horizontal section, second slope, and third slope formed in the waste landfill with a water-blocking plate to prevent rainwater from infiltrating the slopes of the landfill.

[0019] In addition, the present invention has the effect of providing a method for constructing slopes in a waste landfill that can reduce maintenance costs of the landfill by preventing sagging damage to the cutoff plate after construction, by connecting the upper end of the cutoff plate covering the surfaces of the first slope, extended slope, horizontal section, second slope, and third slope to the upper end of the vertical cutoff wall, thereby preventing the cutoff plate from sagging downward and peeling off after construction. Brief explanation of the drawing

[0020] FIG. 1 is a cross-sectional view showing a vertical cutoff wall construction step (S1) for creating a slope of a waste landfill according to the present invention, FIG. 1a is a drawing showing the state in which a vertical cutoff wall is constructed inside a vertical excavation section, and Figure 1b is a drawing showing the state in which a lower concrete reinforcement section is further constructed in the lower part of the interior of the vertical excavation section. FIG. 2 is a cross-sectional view showing the first excavation construction step (S2) of the slope formation method according to the present invention. FIG. 3 is a cross-sectional view showing the step (S3) of constructing the first slope stabilization and purification work of the slope formation method according to the present invention. FIG. 4 is a cross-sectional view showing the second excavation construction step (S4) of the slope formation method according to the present invention. FIG. 5 is a cross-sectional view showing the step (S5) of constructing the second slope stabilization work of the slope formation method according to the present invention. FIG. 6 is a cross-sectional view showing the third excavation construction step (S6) of the slope formation method according to the present invention. FIG. 7 is a cross-sectional view showing the water barrier construction step (S7) of the slope formation method according to the present invention. FIG. 8 is an example diagram illustrating the angle of slope applied to the shape of the soil when excavating a landfill according to conventional regulations. Specific details for implementing the invention

[0021] Preferred embodiments of the present invention are described in more detail below with reference to the accompanying drawings. However, it should be understood that the present invention may be implemented in a number of different forms and is not limited to the described embodiments.

[0022] FIGS. 1 to 7 are drawings sequentially showing each construction step of the slope formation method according to the present invention.

[0023] As illustrated in the drawing, the method for constructing a slope of a waste landfill according to the present invention (hereinafter referred to as the "slope construction method") prevents the excavation surface of the first excavation section from collapsing during the construction of the first excavation section by constructing a vertical cutoff wall on a landfill to be constructed on the original ground and then excavating a first excavation section inside the vertical cutoff wall, and includes a vertical cutoff wall construction step (S1), a first excavation section construction step (S2), a first slope stabilization work construction step (S3), a second excavation section construction step (S4), a second slope stabilization work construction step (S5), and a third excavation section construction step (S6).

[0024] The above vertical cutoff wall construction step (S1) involves constructing a vertical excavation section (1) in the weathered soil layer and weathered rock layer underground of the landfill site to be constructed on the original ground, and then constructing a known vertical cutoff wall (2) inside the vertical excavation section (1).

[0025] The above vertical cutoff wall (2) is a known type and can be selected from sheet piles, SCW (soil cement wail), CIP (cast in place pile), diaphregm wail, continuous underground wall (diaphregm wail), continuous row CIP, and continuous row A-CIP. The description of its specific configuration and construction is omitted.

[0026] In addition, in the above vertical cutoff wall construction step (S1), after constructing a vertical excavation section (1) to a certain depth for the landfill to be formed on the original ground, and before constructing the vertical cutoff wall (2) inside the vertical excavation section (1), a process may be further carried out to construct a concrete reinforcement section in which the vertical cutoff wall (2) is seated at the bottom of the vertical excavation section (1) by injecting and curing concrete at the bottom of the vertical excavation section (1). At this time, although the present invention describes the injection and curing of concrete, urethane foam may also be used.

[0027] Next, the first excavation section construction step (S2) involves excavating the weathered soil on the upper part of the original ground inside the vertical cutoff wall (2) to a certain depth to excavate the first excavation section (3) and forming a first perimeter layer (31) protruding inwardly at the lower part of the first excavation section (3).

[0028] And when forming the first perimeter layer (31), it is preferable to excavate the lower perimeter of the first excavation part (3) into an inclined surface (S), and then cut and level the upper and inner sides of the inclined surface (S) to form the first perimeter layer (31).

[0029] Next, the step (S3) of constructing the first slope stabilization work is to construct the first soil homogenization layer (41), in which soil and cement are mixed in multiple layers, by embanking and compacting it in the first excavation section (3), and to form the first temporary slope (42) that extends upward from the lower inner side to the outer side on the inner side of the first soil homogenization layer (41), and to cut and level the inner side of the first temporary slope (42) to form a vertical surface (43) on the lower inner side of the first soil homogenization layer (41), and to form the first slope (44) that extends upward from the upper side of the vertical surface (43) to the outer side, thereby constructing the first slope stabilization work (4) around the perimeter of the first excavation section (3).

[0030] Next, the second excavation section construction step (S4) involves excavating the weathered soil layer in the inner lower part of the vertical surface (43) down to the weathered rock layer to excavate the second excavation section (5) and forming a second perimeter layer (51) protruding inwardly at the lower part of the second excavation section (5).

[0031] Next, the step (S5) of constructing the second slope stabilization work is to construct a second soil homogenization layer (61) mixed with soil and cement by embanking and compacting it in multiple layers on the inner side of the second excavation part (5) and the inner side of the vertical surface (43), and to form a second temporary slope (62) extending upward from the bottom to the outside on the inner side of the second soil homogenization layer (61), and to cut and level the inner side of the second temporary slope (62) to form an extension slope (63) extending downward from the first slope (44) on the inner side of the second soil homogenization layer (61), and to form a horizontal surface (64) on the lower inner side of the extension slope (63), and to form a second slope (65) extending downward on the lower inner side of the horizontal surface (64), thereby constructing the second slope stabilization work (6).

[0032] Next, the third excavation section construction step (S6) involves excavating the weathered rock layer below the second slope (65) to a certain depth to construct the third excavation section (7), and forming a third slope (71) that is inclined to extend downward from the second slope (65) on the inner side of the third excavation section (7).

[0033] Accordingly, the present invention has the advantage of improving safety during construction by preventing the first excavation section (3) from collapsing during construction by preventing the first excavation section (3) from collapsing during excavation, thereby preventing safety accidents by constructing a vertical cutoff wall (2) on a landfill site to be constructed on the original ground and then excavating the first excavation section (3) inside the vertical cutoff wall (2).

[0034] In addition, in the vertical cutoff wall construction step (S1) of the present invention, the height of the upper part of the vertical cutoff wall (2) is positioned below the original ground surface, and a perimeter groove (11) is further formed on the upper part of the vertical cutoff wall (2), and a plurality of anchor bolts (21) are further installed on the upper part of the vertical cutoff wall (2).

[0035] In addition, after the third excavation construction step (S6), the present invention may further proceed to a water barrier construction step (S7) in which a water barrier plate (8) is further constructed to prevent rainwater from penetrating the slopes of the landfill by covering the first slope (44), the extended slope (63), the horizontal plane (64), the second slope (65), and the third slope (71), and is secured by a nut (N) that is inserted into the circumferential groove (11), penetrates the anchor bolt (21), and is fastened to the anchor bolt (21).

[0036] Accordingly, the present invention has the advantage of preventing rainwater from penetrating the slopes of the landfill and causing them to collapse during the process of burying waste after construction of the landfill by covering the surfaces of the first slope (44), extended slope (63), horizontal plane (64), second slope (65), and third slope (71) formed in the waste landfill with a water barrier plate (8) to prevent rainwater from penetrating the slopes of the landfill.

[0037] In addition, the present invention has the advantage of preventing sagging damage to the water barrier plate (8) after construction by connecting the upper end of the water barrier plate (8) covering the surface of the first slope (44), extended slope (63), horizontal plane (64), second slope (65), and third slope (71) to the upper end of the vertical water barrier wall (2), thereby preventing the water barrier plate (8) from sagging downward and peeling off after construction.

[0038] Although preferred embodiments of the present invention have been described above, the present invention may use various variations, modifications, and equivalents. It is clear that the present invention can be applied in the same way by appropriately modifying the above embodiments. Therefore, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

[0039] Meanwhile, although specific embodiments have been described in the detailed description of the present invention, it will be obvious to those skilled in the art that various modifications are possible within the scope of the present invention. Explanation of the symbols

[0040] 1 : Vertical excavation section 11 : Circumference groove 12: Lower concrete reinforcement 2 : Vertical cutoff wall 21 : Anchor bolt 3: 1st Excavation Section 31: First perimeter layer 4: 1st Slope Stabilization Work 41: First soil homogenization layer 42: First Provisional Amnesty 43 : Vertical plane 44: First Amnesty 5 : 2nd Excavation Section 51: Second perimeter layer 6 : 2nd Slope Stabilization Work 61: Second soil homogenization layer 62: Second Provisional Amnesty 63 : Extended slope 64 : Horizontal plane 65: Second Amnesty 7: Third Excavation Section 71: Third Amnesty 8 : Water barrier

Claims

Claim 1 A vertical cutoff wall construction step (S1) of constructing a vertical excavation section in the weathered soil layer and weathered rock layer of the landfill site to be constructed on the original ground, and then constructing a known vertical cutoff wall inside the vertical excavation section; a first excavation section construction step (S2) of excavating the weathered soil layer above the original ground inside the vertical cutoff wall to a certain depth to excavate a first excavation section and forming a first perimeter layer protruding inwardly at the bottom of the first excavation section; and constructing a first soil homogenization layer mixed with soil and cement in multiple layers around the perimeter of the first excavation section by embanking and compacting it, forming a first temporary slope extending upward from the inner side of the lower part of the first soil homogenization layer to the outer side, cutting and leveling the inner side of the first temporary slope to form a vertical surface at the lower side of the inner part of the first soil homogenization layer, and forming a first slope extending upward from the upper part of the vertical surface to the outer side, thereby forming a first on the inner surface of the first excavation section A step of constructing a slope stabilization work (S3); a step of constructing a second excavation section (S4) by excavating the weathered soil layer in the inner lower part of the vertical surface down to the weathered rock layer to excavate a second excavation section and forming a second perimeter layer protruding inwardly at the bottom of the second excavation section; a step of constructing a second slope stabilization work (S5) by constructing a second soil homogenization layer mixed with soil and cement in multiple layers on the excavation surface of the second excavation section and the inner side of the vertical surface, forming a second temporary slope extending upward from the bottom to the outside on the inner side of the multiple layers of the second soil homogenization layer, cutting and leveling the inner perimeter of the second temporary slope to form an extension slope extending downwardly from the first slope on the inner side of the multiple layers of the second soil homogenization layer, forming a horizontal plane on the lower inner side of the extension slope, and forming a second slope extending downwardly on the lower inner side of the horizontal plane; and the second A method for constructing a slope in a waste landfill, characterized by including a third excavation section construction step (S6) of excavating a weathered rock layer in the inner lower part of the slope to a certain depth to construct a third excavation section and forming a third slope that is inclined to extend downward from the second slope on the inner side of the third excavation section. Claim 2 A method for constructing slopes of a waste landfill according to claim 1, wherein in the vertical cutoff wall construction step (S1), the height of the upper end of the vertical cutoff wall is positioned below the original ground surface, and a perimeter groove is further formed on the upper end of the vertical cutoff wall, and a plurality of anchor bolts are further installed on the upper end of the perimeter vertical cutoff wall, and after the third excavation section construction step (S6), a cutoff plate is inserted into the upper perimeter groove and fixed by a nut that penetrates the anchor bolt and is fastened to the anchor bolt, and a cutoff plate is further installed to cover the first slope, extended slope, horizontal plane, second slope, and third slope to prevent rainwater infiltration into the slopes of the landfill, characterized by further installing a cutoff plate. Claim 3 A method for constructing a slope of a waste landfill according to claim 1, characterized in that in the vertical cutoff wall construction step (S1), after constructing a vertical excavation section to a certain depth for the landfill to be constructed on the original ground, and before constructing the vertical cutoff wall, further proceeding with the process of injecting and curing concrete at the bottom of the vertical excavation section to further construct a lower concrete reinforcement section on which the vertical cutoff wall is seated at the bottom of the vertical excavation section. Claim 4 A method for constructing a slope in a waste landfill according to claim 1, wherein the vertical cutoff wall is one of a sheet pile, an SCW (soil cement wail), a CIP (cast in place pile), a diaphragm wail, a continuous underground wall (diaphregm wail), a continuous row CIP, or a continuous row A-CIP.

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