A cave-type dam abutment groove parallel excavation structure and method

Abstract

The present invention provides a cave-type dam abutment groove parallel excavation structure and method, a cave-type dam abutment groove parallel excavation structure, characterized in that: the dam abutment groove is divided into a plurality of layers along the depth direction, each layer is divided into a plurality of strips along the depth direction of the dam abutment groove, the strips include inwardly inclined bodies and outwardly inclined bodies that are inclined downward in opposite directions, the inwardly inclined bodies and outwardly inclined bodies are cross-distributed, the inwardly inclined bodies are inclined downward from the height of the top of the layer, and the outwardly inclined bodies are inclined downward from the height of the bottom of the inwardly inclined bodies to the bottom of the layer, and horizontal platforms are provided at both ends of each strip. By adopting the excavation structure and method provided by the present invention, the excavation machinery can reach any working surface through the blast avoidance channel to avoid blast, and there is no need to lift up and down by setting up a crane on the top of the cave to reach the working surface and avoid blast, and the excavation height of the dam abutment groove is not affected by the lifting height of the crane; if each layer of the dam abutment groove is divided into a plurality of relatively independent working surfaces for excavation construction, the blasting excavation efficiency and slag discharge efficiency of the dam abutment groove are extremely high.

Description

Technical Field

[0001] The invention belongs to the technical field of dam abutment grooves of hydropower stations, and specifically relates to a cave-type dam abutment groove parallel excavation structure and method. Background Art

[0002] The abutment trough of a hydropower station is located on the mountain slopes on both sides of the dam. It is an important project to support the dam to resist the upstream reservoir water. Nearly 2 / 3 of my country's hydropower resources are distributed in the high mountains and deep valleys of the three southwestern provinces of Sichuan, Yunnan and Tibet. However, the geological conditions in the southwest are complex and the ecological environment is fragile, which poses new challenges to the excavation stability and volume control of the abutment trough of a hydropower station. On the one hand, the deep river valley areas in the southwest have steep natural slopes, high ground stress levels, strong rock unloading, and deep fissures. On the other hand, as the height of the dam continues to break records, the scale of the abutment trough excavation project is also increasing.

[0003] The cave-type abutment trough refers to a "cave" excavated in the mountains on both sides of the arch dam shoulder load, with the top elevation slightly higher than the arch dam crest elevation, and the width at different elevations slightly higher than the arch dam thickness, so that the entire connection between the dam and the mountain is arranged in the "cave". This abutment arrangement method, while meeting the requirements of arch dam foundation treatment and abutment slope stability, cleverly combines the shape of the arch dam body with the high and steep terrain on both sides, which can significantly reduce the amount of excavation engineering and protect the surface vegetation of the mountains on both sides.

[0004] However, with the increasing scale of cave-type abutment trench excavation, the conventional layered and zoned blasting excavation method has great limitations. This excavation method usually requires the installation of a lifting device at the arch position to lift mechanical equipment to avoid blasting and reach the excavation working surface. The lifting height of the lifting device is usually limited, and frequent long-distance lifting of mechanical equipment poses great safety hazards. At the same time, due to the relatively narrow excavation working surface, the processes of blasthole drilling and charging, blasting and slag removal, and abutment trench support usually need to be carried out step by step. Therefore, the difficulty of construction organization is greatly increased and the excavation period of the abutment trench is prolonged. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a cave-type dam shoulder groove parallel excavation structure and method, which solves the above-mentioned technical problems.

[0006] The first object of the present invention is to provide a cave-type dam abutment groove parallel excavation structure:

[0007] A cave-type dam shoulder groove parallel excavation structure, characterized in that: the dam shoulder groove is divided into a plurality of layers along the depth direction, each of the layers is divided into a plurality of strips along the depth direction of the dam shoulder groove, the strips include inwardly inclined bodies and outwardly inclined bodies inclined downwardly towards each other, the inwardly inclined bodies and outwardly inclined bodies are cross-distributed, the inwardly inclined bodies are inclined downwardly from the height of the top of the layer, the outwardly inclined bodies are inclined downwardly from the height of the bottom of the inwardly inclined bodies to the bottom of the layer, and horizontal platforms are provided at both ends of each strip.

[0008] Furthermore, the widths of the inwardly inclined body and the outwardly inclined body are consistent, and their widths should meet the passage conditions of excavation machinery and equipment. The width d1 of the strip body is calculated according to the relationship d1=D / n1, where D is the span of the dam shoulder groove and n1 is the number of strip bodies.

[0009] Furthermore, after the horizontal platforms at both ends of the strip body are connected, an upper blast avoidance channel and a lower blast avoidance channel are formed respectively. The width of the upper blast avoidance channel and the lower blast avoidance channel should meet the passage conditions of excavation machinery and equipment. The horizontal length L1 of the strip body and the width d2 of the blast avoidance channel should satisfy the relationship d=L1+2*d2, where d is the depth of the dam shoulder groove.

[0010] Furthermore, the inclination angles θ of the inwardly inclined body and the outwardly inclined body are consistent, and the inclination angle θ satisfies the following relationship:

[0011] θ=arctan(h / 2 / L1)

[0012] h=H / n

[0013] Among them, h is the layered excavation height, L1 is the horizontal length of the strip, H is the vertical height of the abutment groove, and n is the number of excavation layers.

[0014] The second object of the present invention is to provide a cave-type dam abutment trench parallel excavation method:

[0015] A method for parallel excavation of cave-type dam abutment grooves, characterized in that it comprises the following steps:

[0016] S1: Designing excavation parameters of the dam abutment groove according to the cave-type dam abutment groove parallel excavation structure;

[0017] S2: Determine the first layered excavation area of ​​the abutment slot, and subdivide the inward and outward inclined bodies of the first layered excavation area into several small excavation areas according to the excavation parameters. First, fine blasting is performed on each area of ​​the inward inclined body and the horizontal platforms at both ends. After all the inward inclined bodies are blasted and crushed, slag is discharged in time. At the same time, fine blasting is performed on each excavation area of ​​the outward inclined body and the horizontal platforms at both ends until the cave-like abutment slot parallel excavation structure is formed. The excavation of the first layered excavation area of ​​the abutment slot is completed;

[0018] S3: Determine the second layered excavation area from top to bottom, and excavate all horizontal platforms located on the high side of the inward-inclined body step by step. The excavation height is the layered excavation height; divide the inward-inclined body and the horizontal platform located on the low side of the inward-inclined body into several zones for fine blasting. After the blasting of all inward-inclined bodies is completed, slag can be discharged at the same time;

[0019] The remaining outward inclined bodies and horizontal platforms are gradually blasted and excavated until a cave-like abutment groove parallel excavation structure is formed, and the second layer excavation is completed;

[0020] S4: Repeat step S3 to perform blasting excavation on the remaining layers until the bottom of the abutment groove is reached.

[0021] Furthermore, the excavation parameters include the width d1 of the strip, the horizontal length L1 of the strip, the width d2 of the blast avoidance channel, the number of strips n1, the number of excavation layers n, the vertical height H of the abutment groove, the span D of the abutment groove, and the embedded depth d of the abutment groove, among which the vertical height H of the abutment groove, the span D of the abutment groove and the embedded depth d of the abutment groove are obtained through preliminary geological surveys and abutment groove design plans, and the number of excavation layers n and the excavation zoning are determined in advance by construction personnel based on the excavation volume.

[0022] Furthermore, the inwardly inclined body and the outwardly inclined body are blasted in sequence one by one.

[0023] Furthermore, the crushed stone waste from the cave-like excavation of the dam shoulder trough is dumped from the free surface of the slope to the lower riverbed, and then transported out through the lower road.

[0024] Furthermore, the length of the blasthole located in the first layer excavation area is equal to the corresponding first layer excavation height, and along the excavation direction, the length of the blasthole gradually changes from short to long; the depth of the blastholes from the second layer to the following layers is h.

[0025] Furthermore, when there is a certain slope change in the dam shoulder slope, the horizontal length of the strip and the width of the blast-proof passage can be adjusted; when the span of the dam shoulder groove changes with the elevation, the number and width of the strips can be adjusted.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0027] 1. Excavation machinery can reach any working face through the blast avoidance channel to avoid blasting. There is no need to lift up and down by setting up a crane on the top of the tunnel to reach the working face and avoid blasting. The height of the dam shoulder groove excavation is not affected by the lifting height of the crane.

[0028] 2. Each layer of the abutment groove is divided into multiple relatively independent working surfaces for excavation construction. The blasting excavation efficiency and slag discharge efficiency of the abutment groove are extremely high.

[0029] 3. The processes of blasthole drilling and charging, blasting slag removal, and abutment groove support can be carried out simultaneously, which greatly improves the efficiency of abutment groove excavation.

[0030] 4. The blasting excavation process of the dam shoulder groove can be more refined, and the quality of the shoulder groove excavation is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of excavation of a cave-type dam abutment groove according to an embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram of the first layered excavation area in an embodiment of the present invention.

[0033] Figure 3 Schematic diagram of other layered excavation areas in an embodiment of the present invention.

[0034] Figure 4 It is a schematic diagram of a gunfire avoidance channel according to an embodiment of the present invention.

[0035] Figure 5 This is a schematic diagram of the completion of excavation of the inner inclined body according to an embodiment of the present invention.

[0036] Among them: 1-locking lining, 2-construction hole, 3-upstream side slope, 4-downstream side slope, 5-dam abutment groove excavation contour line, 7-dam abutment groove unexcavated area, 8-first layer excavation area, 9-other layer excavation areas, 10-free surface, 11-inwardly inclined body, 12-outwardly inclined body, 13-upper blast avoidance channel, 14-lower blast avoidance channel, 15-arch end dam foundation, 16-horizontal platform. DETAILED DESCRIPTION

[0037] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0038] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0039] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0040] Reference Figures 1 to 5 An embodiment of the present invention is a cave-type dam shoulder groove parallel excavation structure, characterized in that: the dam shoulder groove is divided into a plurality of layers along the depth direction, each of the layers is divided into a plurality of strips along the depth direction of the dam shoulder groove, the strips include an inwardly inclined body 11 and an outwardly inclined body 12 inclined downwardly towards each other, the inwardly inclined body 11 and the outwardly inclined body 12 are cross-distributed, the inwardly inclined body 11 is inclined downward from the height of the top of the layer, the outwardly inclined body 12 is inclined downward from the height of the bottom of the inwardly inclined body 11 to the bottom of the layer, and horizontal platforms 16 are provided at both ends of each strip.

[0041] The present invention introduces a cave-type dam abutment trench parallel excavation method, which comprises the following steps:

[0042] A construction hole 2 leading to the external road is excavated at the dam crest elevation and supported by a lock lining 1.

[0043] The cave-type abutment trench parallel excavation method first divides the abutment trench excavation into several layers, which are divided into two types according to their different excavation styles, namely the first layer excavation area 8 and the other layer excavation area 9. Each layer is divided into several strips from the upstream side slope 3 to the downstream side slope 4. The strips are divided into two types according to their inclination and excavation direction. One is inclined to the arch end dam foundation 15, and the excavation direction is defined as the inward-inclined body 11 from the empty side 10 to the arch end dam foundation 15; the other is inclined to the empty side 10, and the excavation direction is defined as the outward-inclined body 12 from the arch end dam foundation 15 to the empty side 10.

[0044] In this embodiment, the abutment slope is regarded as a vertical slope, and the horizontal cross-section of the excavated layers is a rectangle.

[0045] S1: First, the excavation parameters of the abutment groove are designed. The excavation parameters include the width d1 of the strip, the horizontal length L1 of the strip, the width d2 of the blast-proof passage, the number of strips n1, the number of excavation layers n, the vertical height H of the abutment groove, the span D of the abutment groove, and the embedded depth d of the abutment groove. The vertical height H of the abutment groove, the span D of the abutment groove and the embedded depth d of the abutment groove are obtained through the preliminary geological survey and the abutment groove design plan. The number of excavation layers n and the division of excavation areas are determined in advance by the construction personnel according to the excavation volume.

[0046] Calculate the width d1 of the strip. In this embodiment, the widths of the inwardly inclined body 11 and the outwardly inclined body 12 are set to be consistent. The widths should meet the passage conditions of excavation machinery and equipment. The width of the strip is calculated according to the relationship d1=D / n1, where D is the span of the dam shoulder groove and n1 is the number of strips.

[0047] The inwardly inclined bodies 11 and the outwardly inclined bodies 12 are cross-distributed. To realize the interconnection of the working surfaces, the number of strip bodies needs to satisfy n1>2.

[0048] Calculate the horizontal length L1 of the strip and the width d2 of the blast avoidance channel. A horizontal platform 16 is provided at both ends of each strip. When the horizontal platforms at both ends are connected, an upper blast avoidance channel 13 and a lower blast avoidance channel 14 are formed. The width of all blast avoidance channels should meet the passage conditions of excavation machinery and equipment. The horizontal length L1 of the strip and the width d2 of the blast avoidance channel should satisfy the relationship d=L1+2*d2, where d is the depth of the dam shoulder groove.

[0049] Calculate the excavation height. The excavation height includes the first layer excavation height and other layer excavation heights. The first layer excavation height increases along the excavation direction, and the other layer excavation heights are calculated according to the relationship h=H / n, where h is the layer excavation height, H is the vertical height of the dam shoulder groove, and n is the number of excavation layers.

[0050] Furthermore, the inclination angle of the strip body is determined. In this embodiment, the inclination angles of all the strip bodies are kept consistent, that is, the inclination angle of the downward excavation is θ, which satisfies the following relationship:

[0051] θ=arctan(h / 2 / L1)

[0052] Furthermore, the horizontal platform 16 can be used for temporary stacking of materials and for mechanical equipment to stay, and its size is affected by the width d2 of the cannon-proof passage and the width d1 of the strip body, and the size of the horizontal platform is d1*d2*h.

[0053] S2: Determine the first layered excavation area 8 of the abutment groove, and subdivide the inwardly inclined body 11 and the outwardly inclined body 12 of the first layered excavation area 8 into several small excavation areas according to the excavation parameters. First, carry out fine blasting on the inwardly inclined body 11 and the various areas of the horizontal platforms 16 at both ends. After all the inwardly inclined bodies 11 are blasted and crushed, the slag is discharged in time. At the same time, the excavation areas of the outwardly inclined body 12 and the horizontal platforms 16 at both ends are drilled and charged, and the blast holes are connected and detonated by detonating cords until the above-mentioned cave-type abutment groove parallel excavation structure is formed. The excavation of the first layered excavation area 8 of the abutment groove is completed.

[0054] The strip body inclination angle θ is determined when the first layered excavation area 8 of the abutment groove is excavated, and the inclination angles of other layered excavations will remain consistent thereafter.

[0055] In order to ensure the safety of mechanical equipment from explosions, all the inwardly inclined bodies 11 are not blasted at the same time, but are blasted one by one from the upstream side to the downstream side. The blasting and excavation of the outwardly inclined body 12 is similar.

[0056] The crushed stone waste from the cave-like excavation of the dam shoulder trough is mainly dumped from the free surface 10 of the slope to the lower riverbed, and then transported out from the lower road.

[0057] S3: After the excavation of the first layered excavation area 8 of the abutment groove is completed, the second layered excavation area is determined in sequence from top to bottom.

[0058] like Figure 3 As shown, for other layered excavation areas 9, firstly, the horizontal platforms of all the inwardly inclined bodies 11 close to the free surface are gradually excavated, and the excavation height is h.

[0059] like Figure 4 As shown, when the horizontal platform is removed by blasting, the lower blast avoidance channel is connected and penetrated, and forms a closed connected channel with the upper blast avoidance channel and each strip body, and mechanical equipment can reach any working surface to perform drilling, slag discharge, support and other operations.

[0060] The inwardly inclined body 11 and the horizontal platform close to the arch end dam foundation are divided into several sections for fine blasting. The blasting excavation of the inwardly inclined body 11 is carried out one by one from the upstream side to the downstream side. After the blasting of all the inwardly inclined bodies 11 is completed, the slag can be discharged at the same time.

[0061] like Figure 5 As shown, after the inwardly inclined body 11 and the horizontal platform near the arch end dam foundation are removed by blasting, the upper blasting channel becomes invalid, but the lower blasting channel can still operate normally. This excavation method can ensure that at least one of the two blasting channels can be used at any time, ensuring that mechanical equipment can reach any working surface.

[0062] After the remaining outward inclined body 12 and the horizontal platform are gradually blasted, a layered excavation is completed.

[0063] S4: Repeat step S3 to perform blasting excavation on the remaining layers until the bottom of the abutment groove is reached.

[0064] In this cave-type dam shoulder trench parallel excavation method, under the same working condition, except for the excavation height of the first layer being different from that of other layers, other parameters remain unified. Therefore, when excavating other layers, the same set of blasting excavation equipment can be used without disassembling and assembling a new set of blasting excavation equipment, which can effectively save time and cost and greatly reduce the operational complexity and construction difficulty of blasting excavation.

[0065] It can realize slag discharge from multiple working faces simultaneously, greatly improving the slag discharge efficiency of dam shoulder groove excavation.

[0066] Due to the connecting function of the blast-avoiding channel, mechanical equipment can be used to reach any working surface in the dam abutment groove. Multiple construction procedures such as drilling, slag discharge, and support construction can be carried out simultaneously on multiple working surfaces, greatly improving the efficiency of dam abutment groove excavation and support construction.

[0067] This excavation method does not require the lifting device to lift the excavation machinery and equipment up and down to avoid blasting and transport it to the working surface. The machinery and equipment can flexibly avoid blasting through the blasting avoidance channel as far away from the blasting area as possible; it avoids the limitation of the lifting distance of the lifting device and the safety hazards of lifting the machinery and equipment up and down. Reliable blasting avoidance protection devices can be arranged on the horizontal platform to make the machinery and equipment safer to avoid blasting.

[0068] Specifically, in step S2 of this embodiment, the excavation height of the first layered excavation area 8 starts from 0m along the excavation direction and increases in an arithmetic progression until its excavation height is equal to h. Further, in step S2, the length of the blasthole located in the first layered excavation area 8 is equal to the corresponding first layer excavation height; along the excavation direction, the length of the blasthole gradually changes from short to long. In order to ensure its forming quality, the first layered excavation area can also be mechanically excavated.

[0069] Preferably, the explosive used in this embodiment is a high-quality emulsion explosive with good explosion performance, high safety and low mechanical sensitivity.

[0070] Since the lower blast avoidance channel is close to the air surface, in order to ensure the safety of mechanical equipment during movement, the width of the lower blast avoidance channel can be widened.

[0071] In step S3 of this embodiment, the length of the blastholes in other layered excavation areas is equal to the height of other layered excavation, that is, the depths of the blastholes from the second layer to the following layers are all consistent.

[0072] After the first layer excavation is completed, the mechanical equipment and various support devices required for excavation are moved to the strip body, and the drilling and blasting excavation of the next layer is carried out. The excavation is gradually advanced downward along the strip body to form a unified and procedural excavation method, which reduces the complexity of the dam shoulder groove blasting excavation construction and improves the excavation efficiency.

[0073] It should be further explained that, in some embodiments, the dam shoulder slope is usually not completely vertical, and there is a certain slope change. The horizontal length of the strip body and the width of the blast-proof channel can be adjusted. This excavation method can also meet the excavation of high and steep dam shoulders with different slopes.

[0074] It should be further explained that in some embodiments, due to the design requirements of the arch dam, the span of the dam shoulder groove will change with the elevation, so the number and width of the strips can be adjusted. This excavation method can also meet the excavation of high and steep dam shoulder grooves of different shapes.

[0075] Of course, the design and creation of the present invention is not limited to the above-mentioned implementation modes. Those skilled in the art may make equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A cave-type dam abutment groove parallel excavation structure, characterized in that: The abutment groove is divided into a plurality of layers along the depth direction, and each layer is divided into a plurality of strips along the depth direction of the abutment groove. The strips include an inwardly inclined body (11) and an outwardly inclined body (12) that are inclined downwardly towards each other. The inwardly inclined body (11) and the outwardly inclined body (12) are cross-distributed. The inwardly inclined body (11) is inclined downwardly from the height of the top of the layer, and the outwardly inclined body (12) is inclined downwardly from the height of the bottom of the inwardly inclined body (11) to the bottom of the layer. Both ends of each strip are provided with horizontal platforms (16); the widths of the inwardly inclined body (11) and the outwardly inclined body (12) are consistent, and their widths should meet the passage conditions of excavation machinery and equipment. After the horizontal platforms (16) at both ends of the strips are connected, an upper blast avoidance channel (13) and a lower blast avoidance channel (14) are formed respectively. The widths of the upper blast avoidance channel (13) and the lower blast avoidance channel (14) should meet the passage conditions of excavation machinery and equipment.

2. The cave-type dam abutment trench parallel excavation structure according to claim 1, characterized in that: The width d1 of the strip body is calculated according to the relationship d1=D / n1, wherein D is the span of the dam shoulder groove and n1 is the number of the strip bodies.

3. The cave-type dam abutment trench parallel excavation structure according to claim 1, characterized in that: The horizontal length L1 of the strip body and the width d2 of the blast-proof channel should satisfy the relationship d=L1+2*d2, where d is the depth of the dam shoulder groove.

4. The cave-type dam abutment trench parallel excavation structure according to claim 1, characterized in that: The inclination angles θ of the inwardly inclined body (11) and the outwardly inclined body (12) are consistent, and the inclination angle θ satisfies the following relationship: θ=arctan(h / 2 / L1) h=H / n Among them, h is the layered excavation height, L1 is the horizontal length of the strip, H is the vertical height of the abutment groove, and n is the number of excavation layers.

5. An excavation method using a cave-type dam abutment trench parallel excavation structure as described in any one of claims 1 to 4, characterized in that: The following steps are involved: S1: Designing excavation parameters of the dam abutment groove according to the cave-type dam abutment groove parallel excavation structure; S2: Determine the first layered excavation area (8) of the abutment groove, and subdivide the inward-inclined body (11) and the outward-inclined body (12) of the first layered excavation area (8) into a number of small excavation areas according to the excavation parameters. First, fine blasting is performed on each area of ​​the inward-inclined body (11) and the horizontal platforms (16) at both ends thereof. After all the inward-inclined bodies (11) are blasted and crushed, slag is discharged in a timely manner. At the same time, fine blasting is performed on each excavation area of ​​the outward-inclined body (12) and the horizontal platforms (16) at both ends thereof until the cave-type abutment groove parallel excavation structure is formed. The excavation of the first layered excavation area (8) of the abutment groove is completed. S3: Determine the second layered excavation area from top to bottom, and excavate all horizontal platforms located on the high side of the inward-inclined body (11) step by step, and the excavation height is the layered excavation height; divide the inward-inclined body (11) and the horizontal platform located on the low side of the inward-inclined body (11) into several zones for fine blasting, and slag can be discharged at the same time after the blasting of all the inward-inclined bodies (11) is completed; The remaining outward inclined body (12) and the horizontal platform are gradually blasted and excavated until a cave-like dam shoulder groove parallel excavation structure is formed, and the second layer excavation is completed; S4: Repeat step S3 to perform blasting excavation on the remaining layers until the bottom of the abutment groove is reached.

6. The method for parallel excavation of cave-type dam abutment grooves according to claim 5, characterized in that: The excavation parameters include the width d1 of the strip, the horizontal length L1 of the strip, the width d2 of the blast avoidance channel, the number of strips n1, the number of excavation layers n, the vertical height H of the abutment groove, the span D of the abutment groove, and the embedded depth d of the abutment groove. The vertical height H of the abutment groove, the span D of the abutment groove and the embedded depth d of the abutment groove are obtained through preliminary geological surveys and abutment groove design plans, and the number of excavation layers n and the excavation zoning are determined in advance by the construction personnel based on the excavation volume.

7. The method for parallel excavation of cave-type dam abutment grooves according to claim 5, characterized in that: The inwardly inclined body (11) and the outwardly inclined body (12) are blasted in sequence one by one.

8. The method for parallel excavation of cave-type dam abutment grooves according to claim 5, characterized in that: The crushed stone waste from the cave-like excavation of the dam shoulder trough is dumped from the free surface of the slope (10) to the lower riverbed and then transported out through the lower road.

9. The method for parallel excavation of cave-type dam abutment grooves according to claim 5, characterized in that: The length of the blasthole located in the first layer excavation area (8) is equal to the corresponding first layer excavation height. Along the excavation direction, the length of the blasthole gradually changes from short to long; the depth of the blastholes from the second layer to the following layers is h.

10. The method for parallel excavation of cave-type dam abutment grooves according to claim 6, characterized in that: When there is a certain slope change on the dam shoulder slope, the horizontal length of the strip and the width of the blast-proof passage can be adjusted; when the span of the dam shoulder groove changes with the elevation, the number and width of the strips can be adjusted.

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