Curtain grouting system for transverse river valley underground steep stratified rock mass
By designing the dam ultra-deep composite grouting curtain and the dam shoulder ultra-deep composite grouting curtain in the steep layered rock mass underground in the transverse river valley, and setting a cross-layer ultra-deep composite grouting curtain and grouting branch hole at the end, the problem of seepage at the bottom of the curtain grouting is solved, and the anti-seepage capability is significantly improved.
Patent Information
- Application Number
- CN202421042771.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-14
- Publication Date
- 2025-04-15
- Estimated Expiration
- 2034-05-14
AI Technical Summary
在横向河谷地下陡立层状岩体中,帷幕灌浆系统容易出现底部绕渗问题,导致防渗效果不佳。
A curtain grouting system was designed, including a dam ultra-deep composite grouting curtain and a dam shoulder ultra-deep composite grouting curtain, which was arranged in the permeable rock body through a grouting corridor, and a cross-layer ultra-deep composite grouting curtain and grouting branch hole were set up at the end to enhance the depth and thickness of the curtain grouting.
It effectively reduces the seepage condition at the bottom of the curtain grouting, improves the anti-seepage capacity, and significantly reduces the leakage of reservoir water to the downstream side rock mass and riverbed.
Smart Images
Figure CN222758932U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a curtain grouting system, in particular to a curtain grouting system for underground steep layered rock masses in transverse river valleys, and belongs to the technical field of design and construction of water conservancy and hydropower engineering structures. Background Art
[0002] (1) Curtain grouting
[0003] Curtain grouting is the process of injecting cement (or other materials) slurry into underground rock mass through drilling and pressure grouting to fill the pores and cracks in the underground rock mass, block the leakage channels in the underground rock mass, and form a continuous water-blocking zone in the dam foundation and the rock mass of the dam shoulders on both sides, so as to reduce the seepage loss of reservoir water upstream of the dam through the dam foundation and the underground rock mass of the dam shoulders on both sides to the downstream, while reducing the uplift pressure of the dam foundation and improving the stability of the dam.
[0004] (2) Definition of transverse valley
[0005] A river valley is a trough-shaped area on the surface caused by the geological action of the river. According to the angle between the direction of the river valley and the direction of the rock formation, the river valley can be divided into the following types:
[0006] ① Transverse valley: a valley where the angle between the valley direction and the rock formation direction is ≥60°;
[0007] ② Oblique valley: a valley with an angle of 30 to 60° between the valley direction and the rock formation direction;
[0008] ③ Longitudinal valley - a valley where the angle between the valley direction and the rock formation direction is ≤30°.
[0009] (3) Definition of lateral valley rock formation dip
[0010] For transverse valleys, they can be divided into the following types according to the different intersection angles between the rock layer and the horizontal plane:
[0011] ①Horizontal rock layer: rock layer with an angle α<5° with the horizontal plane;
[0012] ② Gently inclined rock strata - rock strata with an angle of 5°<α≤30° between the rock surface and the horizontal plane;
[0013] ③ Steeply inclined rock strata - rock strata with an angle of 30°<α≤60° between the rock surface and the horizontal plane;
[0014] ④ Steep rock strata - rock strata where the angle between the rock surface and the horizontal plane is α>60°.
[0015] The rock masses in transverse river valleys are mostly sedimentary rocks or metamorphic rocks. Due to the differences in sedimentary conditions, sedimentary materials and subsequent tectonic actions of each rock layer, there are great differences in the degree of development of pores and fractures of each rock layer and the permeability of the rock mass. There is often a distribution pattern of alternating permeable rock layers (pores and fractures are highly developed, and the rock mass has strong permeability) and relatively impermeable rock layers (pores and fractures are poorly developed, and the rock mass has weak permeability).
[0016] (4) Curtain grouting arrangement for horizontal and gently inclined layered rock mass in transverse valleys
[0017] For horizontal and gently dipping layered rock mass in transverse valleys, the specific conditions of the curtain grouting system are as follows:
[0018] 1) The curtain grouting system consists of two parts: the dam foundation rock curtain grouting and the dam abutment rock curtain grouting on both sides;
[0019] 2) The curtain grouting of the rock mass at the dam foundation is carried out through the grouting gallery set up in the dam. The curtain grouting needs to penetrate into a certain depth of the relatively impermeable rock layer below the dam foundation in the vertical direction;
[0020] 3) The rock curtain grouting of the dam shoulders on both sides is implemented through grouting tunnels set up in the underground mountains on both sides. The grouting tunnels need to penetrate into the relatively fresh rock mass (with fewer cracks) of the permeable rock layer in the horizontal direction, and the curtain grouting needs to penetrate into a certain depth of the relatively impermeable rock layer in the vertical direction.
[0021] 4) The grouting corridor inside the dam and the grouting tunnels on the shoulders of the dam on both sides are located on the same axis (straight line or broken line).
[0022] Since the grouting tunnel penetrates into the relatively fresh rock mass of the permeable rock layer, the curtain grouting in the dam foundation rock mass and the dam shoulders on both sides penetrates into a certain depth in the relatively impermeable rock layer. The curtain grouting system can form a relatively closed water-blocking zone. The anti-seepage effect of the dam foundation and the dam shoulders on both sides is usually better, and the leakage is less.
[0023] (5) Curtain grouting arrangement and main issues for steeply vertical and steeply inclined layered rock mass in transverse valleys
[0024] For the steeply erected and steeply inclined layered rock mass in the transverse river valley, the conventional arrangement scheme of the curtain grouting system is basically the same as that of the curtain grouting of the horizontal layered rock mass. The specific situation is as follows:
[0025] 1) The curtain grouting system consists of two parts: the dam foundation rock curtain grouting and the dam abutment rock curtain grouting on both sides;
[0026] 2) Curtain grouting of the dam foundation rock mass is implemented through the grouting gallery set up inside the dam;
[0027] 3) Curtain grouting of rock masses on both sides of the dam shoulders is carried out through grouting flat tunnels set up in the underground mountains on both sides;
[0028] 4) The grouting corridor inside the dam and the grouting tunnels on the shoulders of the dam on both sides are located on the same axis (straight line or broken line).
[0029] The main problem with this curtain grouting arrangement is that when the grouting gallery and the grouting adit axis happen to be located in steep and steeply inclined permeable rock formations:
[0030] 1) For the dam foundation, since the rock mass below the grouting gallery is located in the permeable rock layer, the conventional curtain grouting depth and thickness have relatively poor water blocking effects, and the bottom seepage problem of curtain grouting is prone to occur in the vertical direction;
[0031] 2) For the dam shoulders on both sides, in addition to the problem of seepage at the bottom of the curtain grouting in the vertical direction, since there is a large permeable space (along the vertical direction) between the grouting flat holes on the dam shoulders on both sides and the relatively impermeable rock layers upstream and downstream, the dam shoulders on both sides are prone to seepage along the horizontal ends of the curtain grouting in the horizontal direction. Utility Model Content
[0032] The technical problem to be solved by the utility model is to provide a curtain grouting system for steep layered rock mass underground in a transverse river valley, which can effectively reduce the seepage condition at the bottom of the curtain grouting and improve the anti-seepage capacity.
[0033] The technical solution adopted to solve the above technical problems is: a curtain grouting system for steep layered rock mass underground in a transverse river valley, including steep layered rock mass at a dam foundation and steep layered rock mass at dam shoulders on both sides, the steep layered rock mass at the dam foundation and the steep layered rock mass at the dam shoulders respectively including staggered permeable rock mass and relatively impermeable rock mass, the curtain grouting system also includes a grouting gallery, an ultra-deep composite grouting curtain at the dam and an ultra-deep composite grouting curtain at the dam shoulders, the ultra-deep composite grouting curtain at the dam shoulders being arranged in the permeable rock mass of the steep layered rock mass at the dam foundation through the grouting gallery, and the ultra-deep composite grouting curtain at the dam shoulders being arranged in the permeable rock mass of the steep layered rock mass at the dam shoulders through the grouting gallery; the storage water in the reservoir area on the upstream side of the dam is reduced in its leakage to the rock mass on the downstream side and to the riverbed on the downstream side through the interconnected ultra-deep composite grouting curtain at the dam and the ultra-deep composite grouting curtain at the dam shoulders.
[0034] Furthermore, the curtain grouting system also includes an end cross-layer ultra-deep composite grouting curtain, and end cross-layer ultra-deep composite grouting curtains perpendicular to the corresponding dam shoulder ultra-deep composite grouting curtains are respectively arranged at the ends of the two sections of dam shoulder ultra-deep composite grouting curtains along the length direction of the dam; along the upstream and downstream directions, both ends of the end cross-layer ultra-deep composite grouting curtains are respectively embedded in the adjacent relatively impermeable rock layers.
[0035] The preferred embodiment of the above scheme is that grouting branch holes are respectively arranged in the steep layered rock mass at both ends of the dam shoulder, the grouting branch holes are connected to the grouting gallery, and the end cross-layer ultra-deep composite grouting curtain is arranged in the steep layered rock mass at the end of the ultra-deep composite grouting curtain at the dam shoulder through the grouting branch holes.
[0036] Furthermore, the grouting gallery includes a dam grouting tunnel and a dam shoulder grouting tunnel. Along the length direction of the dam, the dam grouting tunnel and the dam shoulder grouting tunnel are located on the same axis above the grouting curtain, and the grouting branch tunnel is perpendicular to the axis of the dam shoulder grouting tunnel and connected to the dam shoulder grouting tunnel.
[0037] The preferred embodiment of the above scheme is that the depths of the dam ultra-deep composite grouting curtain, the dam shoulder ultra-deep composite grouting curtain and the end cross-layer ultra-deep composite grouting curtain arranged in the permeable rock mass are all deeper than the depth of the grouting curtain arranged in the relatively impermeable rock mass.
[0038] Furthermore, along the thickness direction, the dam ultra-deep composite grouting curtain, the dam shoulder ultra-deep composite grouting curtain and the end cross-layer ultra-deep composite grouting curtain are all connected by the diffusion and condensation of slurry input from at least two rows of grouting holes.
[0039] A preferred embodiment of the above scheme is that, among the rows of grouting holes, the axis of at least the row of grouting holes located on the upstream side gradually inclines from top to bottom toward the steep layered rock mass on the upstream side.
[0040] Furthermore, among the rows of grouting holes, the axis of the row of grouting holes located on the downstream side gradually inclines from top to bottom toward the steeply layered rock mass on the downstream side.
[0041] The beneficial effects of the utility model are as follows: the technical solution provided by the application is based on the existing steep layered rock mass at the dam foundation and the steep layered rock mass at the dam shoulders on both sides, and combined with the structural characteristics that the steep layered rock mass at the dam foundation and the steep layered rock mass at the dam shoulders respectively include staggered permeable rock mass and relatively impermeable rock mass, by adding grouting corridors, ultra-deep composite grouting curtains at the dam and ultra-deep composite grouting curtains at the dam shoulders to form the curtain grouting system of the application, and then the ultra-deep composite grouting curtains at the dam are passed through The grouting gallery is arranged in the permeable rock mass of the steep layered rock mass of the dam foundation, so that the ultra-deep composite grouting curtain of the dam shoulder is arranged in the permeable rock mass of the steep layered rock mass of the dam shoulder through the grouting gallery; in this way, the storage water in the reservoir area on the upstream side of the dam can be effectively reduced through the interconnected ultra-deep composite grouting curtain of the dam and the ultra-deep composite grouting curtain of the dam shoulder to reduce its leakage to the downstream side rock mass and the downstream side riverbed, so as to effectively reduce the seepage at the bottom of the curtain grouting and improve the anti-seepage capacity. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Figure 1It is a schematic diagram of the main cross-sectional structure of the curtain grouting system of the utility model for steep layered rock mass underground in a transverse river valley;
[0043] Figure 2 for Figure 1 AA section view;
[0044] Figure 3 for Figure 1 BB cross-sectional view;
[0045] Figure 4 for Figure 1 CC cross-sectional view.
[0046] Marked in the figure are: permeable layer rock mass 1, relatively impermeable layer rock mass 2, dam ultra-deep composite grouting curtain 3, dam abutment ultra-deep composite grouting curtain 4, end cross-layer ultra-deep composite grouting curtain 5, grouting branch hole 6, dam grouting flat hole 7, dam abutment grouting flat hole 8, grouting hole 9. DETAILED DESCRIPTION
[0047] like Figure 1 , Figure 2 , Figure 3 as well as Figure 4The utility model shows a curtain grouting system for steep layered rock mass underground in a transverse river valley, which can effectively reduce the bottom seepage of the curtain grouting and improve the anti-seepage ability. The curtain grouting system includes steep layered rock mass at the dam foundation and steep layered rock mass at the abutments on both sides. The steep layered rock mass at the dam foundation and the steep layered rock mass at the abutments respectively include staggered permeable rock mass 1 and relatively impermeable rock mass 2. The curtain grouting system also includes a grouting gallery, an ultra-deep composite grouting curtain 3 at the dam and an ultra-deep composite grouting curtain 4 at the abutments. The ultra-deep composite grouting curtain 3 at the dam is arranged in the permeable rock mass 1 of the steep layered rock mass at the dam foundation through the grouting gallery, and the ultra-deep composite grouting curtain 4 at the abutments is arranged in the permeable rock mass 1 of the steep layered rock mass at the abutments through the grouting gallery. The storage water in the reservoir area on the upstream side of the dam reduces its leakage to the downstream rock mass and the downstream riverbed through the interconnected ultra-deep composite grouting curtain 3 at the dam and the ultra-deep composite grouting curtain 4 at the abutments. The technical solution provided by the present application is based on the existing steep layered rock mass at the dam foundation and the steep layered rock mass at the dam shoulders, and combined with the structural characteristics that the steep layered rock mass at the dam foundation and the steep layered rock mass at the dam shoulders respectively include staggered permeable rock mass and relatively impermeable rock mass, by adding grouting corridors, ultra-deep composite grouting curtains at the dam and ultra-deep composite grouting curtains at the dam shoulders to form the curtain grouting system of the present application, and then the ultra-deep composite grouting curtains at the dam are arranged through the grouting corridors. In the permeable rock mass of the steep layered rock mass at the dam foundation, the super-deep composite grouting curtain at the dam shoulder is arranged in the permeable rock mass of the steep layered rock mass at the dam shoulder through the grouting gallery; in this way, the storage water in the reservoir area on the upstream side of the dam can be effectively reduced from leaking into the rock mass on the downstream side and into the riverbed on the downstream side through the interconnected super-deep composite grouting curtain of the dam and the super-deep composite grouting curtain of the dam shoulder, thereby achieving the purpose of effectively reducing the bypass seepage at the bottom of the curtain grouting and improving the anti-seepage capacity.
[0048] Accordingly, in order to minimize the leakage of the storage water in the upstream dam area, the curtain grouting system described in the present application also includes an end cross-layer ultra-deep composite grouting curtain 5, and the ends of the two sections of the ultra-deep composite grouting curtains 4 at the abutments along the length direction of the dam are respectively arranged with end cross-layer ultra-deep composite grouting curtains 5 perpendicular to the corresponding abutment ultra-deep composite grouting curtains 4; along the upstream and downstream directions, both ends of the end cross-layer ultra-deep composite grouting curtains 5 are respectively embedded in the adjacent relatively impermeable rock mass 2. Combined with the existing technology, in order to facilitate curtain grouting, the present application also arranges grouting branch holes 6 in the steep layered rock mass at the abutments at both ends, and the grouting branch holes 6 are connected to the grouting gallery, and the end cross-layer ultra-deep composite grouting curtains 5 are arranged in the steep layered rock mass at the end of the abutment ultra-deep composite grouting curtain through the grouting branch holes 6. At this time, the grouting corridor usually includes a dam grouting tunnel 7 and a dam shoulder grouting tunnel 8. The dam grouting tunnel 7 and the dam shoulder grouting tunnel 8 are located on the same axis above the grouting curtain along the length direction of the dam; accordingly, the grouting branch tunnel 6 is perpendicular to the axis of the dam shoulder grouting tunnel and connected to the dam shoulder grouting tunnel 8.
[0049] A more specific structure is that the depths of the dam ultra-deep composite grouting curtain 3, the dam shoulder ultra-deep composite grouting curtain 4 and the end cross-layer ultra-deep composite grouting curtain 5 arranged in the permeable layer rock mass 1 are all deeper than the depth of the grouting curtain arranged in the relatively impermeable layer rock mass. And along the thickness direction, the dam ultra-deep composite grouting curtain 3, the dam shoulder ultra-deep composite grouting curtain 4 and the end cross-layer ultra-deep composite grouting curtain 5 are all connected by the slurry diffusion condensation body input from at least two rows of grouting holes 9. At this time, among each row of grouting holes 9, at least the axis of the row of grouting holes 9 located on the upstream side gradually tilts from top to bottom toward the steep layered rock mass on the upstream side; the axis of the row of grouting holes 9 located on the downstream side gradually tilts from top to bottom toward the steep layered rock mass on the downstream side. In this way, a deeper anti-seepage curtain can be formed, and at the same time, an anti-seepage curtain with a thick lower end and a thin upper end can be formed, so as to maximize the anti-seepage capacity of the anti-seepage curtain. Here, the depths of the dam ultra-deep composite grouting curtain 3, the dam shoulder ultra-deep composite grouting curtain 4 and the end cross-layer ultra-deep composite grouting curtain 5 are all deeper than the depth of the grouting curtain arranged in the relatively impermeable layer rock mass, which means that when the grouting curtain is located in the relatively impermeable layer rock mass, the depths of various grouting curtains arranged in the permeable layer rock mass 1 in this application are all deeper than it.
[0050] In summary, the curtain grouting system of the present application also has the following advantages:
[0051] (1) Good water-blocking effect.
[0052] Mainly reflected in:
[0053] 1) For curtain grouting of the dam foundation rock mass: the increase in curtain grouting depth will extend the seepage path around the bottom of the curtain grouting, increase the difficulty of leakage, and significantly reduce the bottom seepage amount; the increase in the number and thickness of curtain grouting rows will improve the permeability stability of the curtain grouting, and the leakage amount through the curtain grouting itself will also be significantly reduced.
[0054] 2) Curtain grouting of rock mass on both sides of the dam abutment;
[0055] ① In the horizontal direction, through the setting of grouting branch holes, the grouting horizontal holes and the relatively impermeable rock layers upstream and downstream form a closed water-blocking zone. It is difficult for the water flow in the upstream reservoir to seep to the downstream along the upper end of the grouting horizontal hole through the pores and cracks in the rock mass.
[0056] ② In the vertical direction, the increase in the depth of curtain grouting will extend the seepage path around the bottom of the curtain grouting, increase the difficulty of leakage, and significantly reduce the leakage around the bottom; the increase in the number and thickness of curtain grouting rows will improve the permeability stability of the curtain grouting, and the leakage through the curtain grouting itself will also be significantly reduced.
[0057] (2) Simple layout and convenient construction. Compared with the conventional scheme, this application only adds grouting branch holes at the ends of the grouting flat holes on both sides of the dam shoulder, and makes minor adjustments to the depth, number of rows and thickness of the curtain grouting. Its layout is relatively simple and the construction is convenient.
[0058] (3) Applicable to steep layered rock mass in transverse river valleys. This application significantly improves the water blocking effect and permeability stability of curtain grouting by adding grouting branch holes at the ends of the grouting flat holes on both sides of the dam shoulders and making minor adjustments to the depth, number of rows and thickness of curtain grouting. The adaptability of the curtain grouting system in steep layered rock mass in transverse river valleys will also be significantly improved.
[0059] The technical solution of the present application is further described below through specific embodiments:
[0060] Embodiment 1
[0061] The technical problem to be solved by the present application is to provide an underground rock curtain grouting system and its arrangement method which is suitable for steep layered rock masses in transverse river valleys, has good water blocking effect, is simple in arrangement and convenient in construction.
[0062] The technical solution adopted by this application to solve the above technical problems is:
[0063] 1. Main structural features of this application:
[0064] a. The curtain grouting system consists of two parts: the dam foundation rock curtain grouting and the dam abutment rock curtain grouting on both sides.
[0065] b. The dam foundation rock curtain grouting is implemented through a grouting gallery set up inside the dam, and the following enhancements are made compared with the conventional scheme:
[0066] (a) Increased depth of curtain grouting;
[0067] (b) Increase the number of rows of curtain grouting;
[0068] (c) A certain angle is set between the upstream and downstream rows of the curtain grouting so that the thickness of the curtain grouting gradually increases from top to bottom, but it is ensured that the bottom of the upstream and downstream rows are still within the slurry diffusion connection range.
[0069] c. The rock curtain grouting of the dam shoulders on both sides is implemented through grouting horizontal tunnels and grouting branch tunnels set in the underground mountains on both sides. The grouting branch tunnels are located at the ends of the grouting horizontal tunnels on the dam shoulders on both sides close to the mountain.
[0070] d. The grouting corridor located inside the dam and the grouting horizontal tunnels located on the dam shoulders on both sides are located on the same axis (straight line or broken line), and the axis of the grouting branch tunnel intersects with the axis of the grouting horizontal tunnel at a large angle.
[0071] e. The grouting branch tunnels penetrate into a certain depth of relatively impermeable rock layers upstream and downstream.
[0072] f. The rock curtain grouting of the dam shoulders on both sides has been strengthened as follows compared with the conventional scheme:
[0073] (a) Increased depth of curtain grouting;
[0074] (b) Increase the number of rows of curtain grouting;
[0075] (c) A certain angle is set between the upstream and downstream rows of the curtain grouting so that the thickness of the curtain grouting gradually increases from top to bottom, but it is ensured that the bottom of the upstream and downstream rows are still within the slurry diffusion connection range.
[0076] 2. Specific implementation scheme of this application
[0077] a. The first step is to excavate the dam foundation simultaneously, and grout the flat holes and branch holes on the abutments of both sides;
[0078] b. The second step is to pour the dam concrete to form the concrete cover and grouting gallery;
[0079] c. The third step is to complete curtain grouting construction such as drilling, grouting and inspection in the grouting gallery, grouting flat tunnel and grouting branch tunnel simultaneously with the pouring of dam concrete on the upper part of the grouting gallery, depending on the formation of concrete cover weight.
Claims
1. A curtain grouting system for steeply layered rock mass underground in a transverse river valley, comprising steeply layered rock mass at a dam foundation and steeply layered rock mass at abutments on both sides of the dam, wherein the steeply layered rock mass at the dam foundation and the steeply layered rock mass at abutments respectively comprise alternatingly distributed permeable rock mass layers (1) and relatively impermeable rock mass layers (2), characterized in that: The curtain grouting system further comprises a grouting gallery, a dam ultra-deep composite grouting curtain (3) and a dam shoulder ultra-deep composite grouting curtain (4); the dam ultra-deep composite grouting curtain (3) is arranged in the permeable rock layer (1) of the steep layered rock mass of the dam foundation through the grouting gallery, and the dam shoulder ultra-deep composite grouting curtain (4) is arranged in the permeable rock layer (1) of the steep layered rock mass of the dam shoulder through the grouting gallery; the storage water in the reservoir area on the upstream side of the dam is reduced in the amount of leakage to the downstream side rock mass and the downstream side riverbed through the interconnected dam ultra-deep composite grouting curtain (3) and the dam shoulder ultra-deep composite grouting curtain (4).
2. The curtain grouting system for steep layered rock mass in underground transverse valleys according to claim 1, characterized in that: The curtain grouting system further comprises an end cross-layer ultra-deep composite grouting curtain (5), wherein end cross-layer ultra-deep composite grouting curtains (5) perpendicular to the corresponding dam shoulder ultra-deep composite grouting curtains (4) are respectively arranged at the ends of the two sections of dam shoulder ultra-deep composite grouting curtains (4) along the length direction of the dam; and along the upstream and downstream directions, both ends of the end cross-layer ultra-deep composite grouting curtains (5) are respectively embedded in the adjacent relatively impermeable rock mass (2).
3. The curtain grouting system for steep layered rock mass in underground transverse valleys according to claim 2 is characterized in that: Grouting branch holes (6) are arranged in the steep layered rock mass at both ends of the dam shoulder, and the grouting branch holes (6) are connected to the grouting gallery. The end cross-layer ultra-deep composite grouting curtain (5) is arranged in the steep layered rock mass at the end of the ultra-deep composite grouting curtain at the dam shoulder through the grouting branch holes (6).
4. The curtain grouting system for steep layered rock mass in underground transverse valleys according to claim 1, 2 or 3, characterized in that: The grouting gallery comprises a dam grouting flat tunnel (7) and a dam shoulder grouting flat tunnel (8). Along the length direction of the dam, the dam grouting flat tunnel (7) and the dam shoulder grouting flat tunnel (8) are located on the same axis above the grouting curtain, and the grouting branch tunnel (6) is perpendicular to the axis of the dam shoulder grouting flat tunnel and communicates with the dam shoulder grouting flat tunnel (8).
5. The curtain grouting system for steep layered rock mass in underground transverse valleys according to claim 4, characterized in that: The depths of the dam ultra-deep composite grouting curtain (3), the dam shoulder ultra-deep composite grouting curtain (4) and the end cross-layer ultra-deep composite grouting curtain (5) arranged in the permeable rock mass (1) are all deeper than the depth of the grouting curtain arranged in the relatively impermeable rock mass.
6. The curtain grouting system for steep layered rock mass underground in transverse river valleys according to claim 5, characterized in that: Along the thickness direction, the dam ultra-deep composite grouting curtain (3), the dam shoulder ultra-deep composite grouting curtain (4) and the end cross-layer ultra-deep composite grouting curtain (5) are all connected by grouting diffusion condensation bodies input from at least two rows of grouting holes (9).
7. The curtain grouting system for steep layered rock mass in underground transverse valleys according to claim 6, characterized in that: Among the rows of grouting holes (9), the axis of at least the row of grouting holes (9) located on the upstream side gradually inclines from top to bottom toward the steeply layered rock mass on the upstream side.
8. The curtain grouting system for steep layered rock mass in underground transverse valleys according to claim 7, characterized in that: Among the rows of grouting holes (9), the axis of the row of grouting holes (9) located on the downstream side gradually inclines from top to bottom toward the steep layered rock mass on the downstream side.