Overflow type immersed roadbed structure

Abstract

The utility model discloses an overflow type immersed roadbed structure. A roadbed main body is composed of backfilled gravelly soil and slope protection; a roadbed backfilling area is arranged below the pavement structure layer, the roadbed backfilling area is composed of backfilled gravelly soil, and an overflow channel is arranged on the geological condition stable side of the roadbed; a high-pressure jet grouting diaphragm wall is arranged in the center of the roadbed, and the bottom of the high-pressure jet grouting diaphragm wall extends to bed rock; by means of the design of the overflow channel, it is guaranteed that flood can be smoothly discharged under the condition of the designed flood level, the situation that the roadbed is damaged due to the fact that the flood overflows the dam is avoided, the overflow channel foundation is reinforced through consolidation grouting, and it is guaranteed that the overflow dam structure is stable and safe; through the design of the high-pressure jet grouting diaphragm wall and the gabion protection slope, the stability of the roadbed under the condition of high water level is ensured, and the risks of leakage and landslide are reduced.

Description

Technical Field

[0001] This utility model belongs to the technical field of water conservancy engineering and road engineering, and relates to overflow-type submerged roadbed structure. Background Technology

[0002] Traditional flood-prone embankment structures: Traditional flood-prone embankments mostly adopt earth-rock dam structures. Long-term immersion of the roadbed slope will reduce the safety factor of the roadbed slope, especially under the action of dynamic water pressure, the anti-sliding force on the slope slip surface will decrease, thereby further weakening the stability of the slope. At present, most of them use the method of thickening the upstream slope to enhance the stability of the roadbed. The seepage prevention of traditional flood-prone embankments mainly depends on the seepage prevention performance of the roadbed dam backfill material. A single seepage prevention measure cannot adapt to complex hydrogeological conditions, and the leakage problem is difficult to control effectively.

[0003] Traditional flood-prone embankments mainly adopt the design concept of water blocking, which cannot effectively and timely discharge water from the upstream of the roadbed. They cannot adapt to the flood discharge needs of different flood frequencies, which can easily lead to flooding and affect the stability of the roadbed.

[0004] Traditional flood-prone embankment structures are difficult to maintain and repair after floods, affecting road durability. Bridge solutions, on the other hand, are costly, complex to construct, and time-consuming. Therefore, a roadbed structure with good stability and durability is needed to meet the requirements of modern engineering. Utility Model Content

[0005] The purpose of this invention is to provide an overflow-type flood-prone roadbed structure to solve the problems of insufficient flood discharge capacity and poor seepage prevention effect of traditional flood-prone embankments.

[0006] The technical solution adopted in this utility model is an overflow-type submerged roadbed structure. The main body of the roadbed consists of backfilled gravel and soil and slope protection. Below the pavement structure layer is the roadbed backfill area, which consists of backfilled gravel and soil. The overflow channel is set on the side of the roadbed with stable geological conditions. A high-pressure jet grouting anti-seepage wall is set at the center of the roadbed, and the bottom of the high-pressure jet grouting anti-seepage wall extends to the bedrock. The upstream and downstream slopes of the roadbed are protected by gabion stone cages and concrete beam slope protection.

[0007] The feature of this utility model is that,

[0008] The foundation of the overflow channel is an integrally consolidated grouting layer.

[0009] The overflow channel adopts a free overflow weir structure, and the inlet elevation of the overflow channel is consistent with the design normal water level.

[0010] The overflow channel consists of a sequentially connected intake channel section, culvert section, spillway section, and stilling basin section.

[0011] The diversion channel is a rectangular open channel with retaining walls on the sidewalls, forming an integral structure; the bottom slab structure is a C15 concrete cushion layer + C25 concrete, with the C15 concrete cushion layer being 10cm thick and the C25 concrete being 80cm thick. The diversion channel is located on the upstream side of the roadbed.

[0012] The culvert section is a rectangular culvert, which is an 80cm thick reinforced concrete structure, with a C15 concrete pad layer under the bottom slab of the culvert.

[0013] The spillway section is a downward sloping section with a gradient of 1:2.5. It is rectangular in shape, made of reinforced concrete, with a C15 concrete cushion layer on the bottom slab and retaining walls on the side piers.

[0014] The stilling basin section adopts a bottom flow energy dissipation type energy dissipation basin, and its structure is basically the same as that of the discharge channel section.

[0015] The upstream and downstream slopes of the roadbed are 1:2.

[0016] A high-pressure jet grouting anti-seepage wall with a thickness of 60cm is installed at the center of the roadbed.

[0017] The beneficial effects of this utility model are:

[0018] 1. Highly efficient flood discharge: The overflow channel of this utility model is closely integrated with the roadbed structure, ensuring flood discharge capacity while reducing construction difficulty and cost. Through the overflow channel design, it is ensured that floods can be discharged smoothly under the design flood level, avoiding damage to the roadbed caused by flood overflow. The foundation of the overflow channel is reinforced with consolidation grouting to ensure the safety and stability of the overflow dam structure.

[0019] 2. Roadbed stability: The design of high-pressure jet grouting anti-seepage wall and gabion slope protection ensures the stability of the roadbed under high water level conditions and reduces the risk of leakage and landslide.

[0020] 3. Economic efficiency: Compared with traditional bridge protection, this utility model has a low structural cost, is easy to construct, and has a short construction period. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overflow-type submerged roadbed structure of this utility model.

[0022] Figure 2 This is a layout diagram of the high-pressure jet grouting anti-seepage wall of this utility model.

[0023] Figure 3 This is a cross-sectional view of the irrigation canal section of this utility model.

[0024] Figure 4 This is a cross-sectional view of the culvert section of this utility model.

[0025] Figure 5 This is a cross-sectional view of the drainage channel section of this utility model.

[0026] Figure 6 This is a cross-sectional view of the stilling basin section of this utility model.

[0027] Figure 7 This is a cross-sectional view of the overflow channel of this utility model.

[0028] In the diagram: 1-Pavement structure layer, 2-Subgrade backfill area, 3-Ground line, 4-High-pressure jet grouting anti-seepage wall, 5-Overflow channel, 51-Diversion channel section, 52-Culvert section, 53-Drainage channel section, 54-Energy stilling basin section; 6-Concrete spiked wall, 7-Consolidation grouting layer, 8-Gabion slope protection, 9-Concrete beam. Detailed Implementation

[0029] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0030] Example 1

[0031] The overflow-type submerged roadbed structure of this utility model, such as Figure 1-7 As shown, the main body of the roadbed consists of backfilled gravel and soil and slope protection; below the pavement structure layer 1 is the roadbed backfill area 2, which consists of backfilled gravel and soil; the overflow channel 5 is located on the side of the roadbed with stable geological conditions; a high-pressure jet grouting anti-seepage wall 4 is set at the center of the roadbed, and the bottom of the high-pressure jet grouting anti-seepage wall 4 extends to the bedrock; the upstream and downstream slopes of the roadbed are protected by concrete beams 9 and gabion stone cage slope protection 8; the upstream and downstream slopes of the roadbed are 1:2; the area above the ground line 3 (i.e., the rock boundary line) is the backfilled part, and the area below the ground line is the part that needs to be excavated.

[0032] Compared to traditional flood-prone embankments, this invention features an overflow channel on the side of the roadbed with stable geological conditions. The section crossing the road is a culvert, while other sections are open channels. The overflow channel dimensions are determined based on flood discharge calculations. The overflow channel ensures the safe outflow of design floodwater. The overflow channel sits on sandy mudstone, and its foundation utilizes consolidation grouting to guarantee structural stability. A high-pressure jet grouting anti-seepage wall is installed at the center of the flood-prone embankment. The bottom of the anti-seepage wall penetrates the rock at least 50cm, preventing water seepage from the downstream side of the roadbed and protecting the roadbed from water infiltration damage.

[0033] Example 2

[0034] Based on Example 1, the overflow channel 5 is based on an integrally consolidated grouting layer 7.

[0035] Overflow channel 5 adopts a free overflow weir structure, and the inlet elevation of the overflow channel is consistent with the design normal water level.

[0036] The overflow channel 5 includes a diversion channel section 51, a culvert section 52, a spillway section 53, and a stilling basin section 54 connected in sequence.

[0037] Section 51 of the diversion channel is a rectangular open channel with retaining walls on the sidewalls, forming an integral structure; the bottom slab structure is a C15 concrete cushion layer + C25 concrete, with a cushion layer thickness of 10cm and a C25 concrete thickness of 80cm. The diversion channel section is located on the upstream side of the roadbed.

[0038] Section 52 of the culvert is a rectangular culvert with an 80cm thick reinforced concrete structure. The bottom slab is equipped with a C15 concrete cushion layer with a thickness of 10cm.

[0039] The drainage section 53 is a downward sloping section with a slope of 1:2.5. It is rectangular in shape and constructed of C25 reinforced concrete. The bottom slab is equipped with a C15 concrete cushion layer.

[0040] The stilling basin section 54 adopts a bottom flow energy dissipation type energy dissipation basin, and its structure is basically the same as that of the discharge channel section.

[0041] A high-pressure jet grouting anti-seepage wall with a thickness of 60cm is installed at the center of the roadbed.

[0042] Example 3

[0043] The overflow-type submerged roadbed structure of this utility model consists of a roadbed main body composed of backfilled gravel and soil and slope protection; a roadbed backfill area 2 is set below the pavement structure layer 1, which is composed of backfilled gravel and soil; an overflow channel 5 is set on the side of the roadbed with stable geological conditions; a high-pressure jet grouting anti-seepage wall 4 is set at the center of the roadbed, and the bottom of the high-pressure jet grouting anti-seepage wall 4 extends to the bedrock; the upstream and downstream slopes of the roadbed are protected by concrete beams 9 and gabion stone cage slope protection 8.

[0044] 1. Roadbed Main Structure Design: The main roadbed consists of backfilled crushed stone and soil, and slope protection. The upstream and downstream slopes of the roadbed are 1:2, and the design elevation of the roadbed is determined based on the design flood level. This ensures the bearing capacity and stability of the roadbed, and guarantees safety under flood and high water level conditions.

[0045] 2. Overflow Channel Structure Design: The overflow channel is located on the side of the roadbed with stable geological conditions and adopts a free overflow weir structure. The inlet elevation of the overflow channel is consistent with the design normal storage level. The overflow channel consists of an intake channel section, a culvert section, a spillway section, and a stilling basin section. Through the overflow channel design, it is ensured that floodwater can be discharged smoothly under the design flood level, avoiding flooding and damage to the roadbed.

[0046] 3. Anti-seepage wall structure design: A high-pressure jet grouting anti-seepage wall with a thickness of 60cm is set at the center of the roadbed, and the bottom extends into the bedrock for no less than 50cm to prevent water flow from damaging the roadbed.

[0047] 4. Gabion Slope Protection Design: Gabion cages are used for protection on both the upstream and downstream slopes of the roadbed. The slope protection consists of geotextile filter cloth + 10cm thick crushed stone cushion layer + 50cm thick gabion cages. Because gabion cage slope protection is a flexible structure, it can well adapt to the water pressure upstream and downstream of the roadbed, thus ensuring the stability of the roadbed structure. Gabion cages are an ecological slope protection method, both environmentally friendly and aesthetically pleasing. Gabion cage slope protection increases the slope's erosion resistance, ensuring the stability of the roadbed under flood impact.

[0048] Example 4

[0049] Based on Example 1 and according to hydrological calculations, the overflow channel's structural dimensions can meet the design flood discharge requirements when the design flood level is reached. The overflow channel mainly consists of an intake channel section, a culvert section, a spillway section, and a stilling basin section.

[0050] The entire overflow channel is built on sandy mudstone, and the foundation is treated with consolidation grouting, with a spacing of 3m and a depth of 5m.

[0051] The upstream and downstream length of the diversion channel is 37m. It is a rectangular open channel with a flow dimension of 10m × 2.8m. The sidewalls are retaining walls, forming an integral structure. The bottom slab structure consists of a 10cm thick C15 concrete cushion layer and an 80cm thick C25 concrete layer.

[0052] The upstream and downstream length of the underpass box culvert section is 33m. It consists of two rectangular culverts with spans of 4.7m × 2m. The bottom slab structure is composed of a 10cm thick C15 concrete cushion layer and an 80cm thick C25 concrete layer, with a 60cm thick concrete central wall.

[0053] The upstream and downstream length of the open channel spillway section is 36m, the aperture size is 10m×3m, the slope of the sloping section is 1:2.5, and the bottom slab structure consists of a 10cm thick C15 concrete cushion layer + an 80cm thick C25 concrete layer.

[0054] The stilling basin section is 27m long upstream and downstream and 0.6m thick. The stilling basin adopts the bottom flow energy dissipation type and has a depth of 2m.

[0055] An overflow channel is designed with a settlement joint every 9m. The inner side of the joint is designed with copper waterstop + BW-Ⅱ waterstop strip 2cm×2cm. The joint filling material is low foam polyethylene closed-cell foam board (2cm thick).

[0056] Example 5

[0057] Design of flooded embankments:

[0058] When combining a flood-prone embankment with an existing earthen dam, the embankment is typically widened upstream of the original dam, facing the existing roadbed. To reduce uneven settlement between the old and new roadbeds, the compaction degree of the widened section is required to be increased by 1%. If the embankment height in the widened section exceeds 1.5m, steps must be excavated, with a step width of 1m, and a 1:1 slope treatment. The top of the original earthen dam is excavated, removing 2m of the original artificial fill and replacing it with crushed stone. Two layers of steel-plastic geogrid are then placed 70cm and 80cm below the pavement structure layer to reduce uneven settlement between the original earthen dam and the newly constructed flood-prone embankment.

[0059] For flooded high embankments, crushed stone soil is mainly used to replace the silty soil with low bearing capacity at the bottom. Layered compaction (each layer is about 20cm to 40cm thick) is adopted, and the compaction machinery is a vibratory roller with a weight of more than 12t, with a compaction degree of not less than 0.96.

[0060] ① Stability calculation and analysis of high embankment slopes submerged in water

[0061] a) Material physical parameters

[0062] The calculation parameters for dam materials are determined based on material test results and analogies with similar projects. The calculation parameters for the stability of the high embankment slope protection under water immersion are shown in Table 1.

[0063] Table 1. Calculation Parameters for Slope Stability of Flooded High Embankment Revetments

[0064]

[0065] b) Computational analysis methods

[0066] The calculation section is the maximum cross-section of the flooded high embankment. The foundation is vertically taken from the bedrock surface, and horizontally extended 60m upstream from the dam toe and 60m downstream from the dam foot, which serves as the calculation model for this project.

[0067] The calculations were performed using the Autobank 6.1 program, a finite element analysis system for hydraulic structures developed by the Institute of Engineering Mechanics at Hohai University. This program is easy to use. Using finite element technology, seepage, displacement, stress-strain analysis, and slope stability calculations can be performed on earth dams.

[0068] This project uses the Bishop method (circular arc method) to analyze the design flood level and normal water storage level of the flooded high embankment slope under normal working conditions.

[0069] d) Calculation results and analysis

[0070] The results of the slope stability calculation (Bishop method) are shown in Table 2.

[0071] Table 2. Calculation results of slope stability of flooded high embankment.

[0072]

[0073] The calculation results show that the slope protection anti-sliding stability safety factor is greater than 1.3 under normal operating conditions. This means that the earth-rock slope protection is stable under various operating conditions at all stages and has a certain safety reserve. Its stability meets the requirements of the specifications.

[0074] Example 6

[0075] Seepage calculation and analysis of gabion slope protection in overflow-type submerged roadbed structure of this utility model:

[0076] Two-dimensional seepage calculations for slope protection and embankment foundation were performed using the AutoBank 7.16 program developed by Hohai University. This analysis system can perform both steady-state and unsteady-state seepage calculations.

[0077] a) Seepage calculation case

[0078] Dam seepage calculations are divided into steady-state seepage and unsteady-state seepage, with calculation conditions including normal water level and design flood. The normal water level and design flood level conditions are calculated as steady-state seepage.

[0079] b) Calculate characteristic water levels

[0080] The characteristic water levels used in the seepage calculation are shown in Table 3.

[0081] Table 3 Characteristic water levels and corresponding downstream water levels

[0082]

[0083] c) Calculate parameters

[0084] The permeability coefficient was calculated based on a comprehensive selection of data from field geological tests, laboratory material tests, relevant overburden test data in the geological report, and the "Code for Geological Exploration of Hydropower Projects" (GB50287-2006).

[0085] d) Calculation results and analysis

[0086] After analysis and organization, the results mainly include the maximum overflow seepage gradient and location, the overflow elevation of the phreatic line, and the unit width seepage flow rate. The results are shown in Table 4. The distribution of the phreatic line, hydraulic head equipotential line, and hydraulic pressure equipotential line of the slope protection under various working conditions is also shown.

[0087] Table 4. Results of Dam Seepage Calculation and Analysis

[0088]

[0089] Based on the above seepage calculation results, the high-pressure jet grouting cutoff wall has a good water-blocking effect. The main seepage gradient is borne by the cutoff wall, while the seepage gradient of the main gravel material is very small. The phreatic line inside the dam drops sharply when passing through the core of the cutoff wall, and the elevation of the overflow point is consistent with the downstream water level. The seepage gradient at the overflow point is 1.94E-03~2.10E-03, which is less than the allowable gradient. The calculated seepage per unit width of the cross-section is 1.09E-04m. 3 / s·m~1.71E-04m 3 / s·m, with a smaller total leakage rate compared to typical engineering projects.

[0090] e) Calculation of discharge capacity

[0091] The overflow channel uses the weir flow calculation formula to calculate the discharge capacity.

[0092] The weir flow formula is as follows:

[0093]

[0094] In the formula:

[0095] Q—Flow rate (m) 3 / s);

[0096] —Gate pier shrinkage coefficient;

[0097] m—flow coefficient;

[0098] B—Width of the orifice, in meters;

[0099] H0—Total head above the weir, including flow velocity, in meters (m).

[0100] The results of the discharge capacity calculation are shown in Table 5.

[0101] Table 5 Overflow Channel Water Level-Flow Rate Relationship

[0102]

[0103] As can be seen from the tables above, the design scale of the flood discharge structure with a 2-hole opening size of 4.7m×2m meets the flood discharge requirements under the design peak flow conditions.

[0104] f) Energy dissipation and shock protection calculations

[0105] Energy dissipation and scour prevention are calculated according to the formula in Appendix B of the "Design Code for Sluice Gates" (SL265-2016).

[0106] ① Calculation of stilling basin depth

[0107] d=σ0×hc"-hs'-Δz

[0108] Where: d—depth of stilling basin (m);

[0109] σ0—hydraulic jump submersion coefficient, which can be 1.05~1.10;

[0110] h c″ —Water depth after the jump (m);

[0111] The calculation formula is as follows:

[0112]

[0113] Where: h s' —Depth of the riverbed outside the pool (m);

[0114] Δz—Water level drop at the outlet of the stilling basin (m);

[0115] The calculation formula is as follows:

[0116]

[0117] Where: φ—the velocity coefficient of water flow at the outlet of the self-cooling pool;

[0118] h c — Shrinkage water depth (m);

[0119] The calculation formula is as follows:

[0120]

[0121] In the formula: —The water kinetic energy correction coefficient can be 1.1~1.05;

[0122] Q—Flow rate per unit width of the overflow weir (m³) 2 / s);

[0123] b1, b2 — Width of the first and last ends of the stilling basin (m);

[0124] T0—Total potential energy measured from the top surface of the stilling basin bottom plate.

[0125] ② Calculation of stilling basin length

[0126] L sj = L s +βL j

[0127] L j =6.9×(h) c" - h c )

[0128] In the formula: L sj —Length of stilling basin (m);

[0129] L s—Horizontal projected length of the stilling basin slope section (m);

[0130] L j — Hydraulic jump length (m);

[0131] h c″ —Water depth after the jump (m);

[0132] h c — Shrinkage water depth (m);

[0133] β—the correction factor for the hydraulic jump length, which can be 0.7~0.8.

[0134] ③ Calculation of stilling basin bottom slab thickness

[0135] The thickness of the stilling basin bottom slab can be calculated according to the following formulas based on the requirements for erosion resistance and buoyancy resistance, and the larger value should be taken.

[0136] Impact resistance calculation formula:

[0137]

[0138] Anti-buoyancy calculation formula:

[0139]

[0140] Where: t—thickness of the bottom plate of the stilling basin at the beginning (m);

[0141] — The difference in water level between the upstream and downstream sides when the gate is releasing water (m);

[0142] k1—Calculation coefficient for the stilling basin bottom slab, which can be 0.15~0.20;

[0143] k2—Safety factor for the stilling basin bottom slab, which can be 1.1~1.3;

[0144] U—Uplift pressure (kPa) acting on the bottom surface of the stilling basin.

[0145] W—the weight of water acting on the top surface of the stilling basin bottom plate (kPa).

[0146] P m —Pulsating pressure (kPa) acting on the bottom plate of the stilling basin.

[0147] —Saturated unit weight of stilling basin bottom slab (kN / m3).

[0148] The thickness at the end of the stilling basin can be t / 2, but should not be less than 0.5m.

[0149] ④ Calculation of sea length

[0150] The calculation formula is:

[0151]

[0152] Where: Lp—ocean length (m);

[0153] K s —Sea length calculation factor (m);

[0154] q s —Stationary pool end unit width flow rate (m²) 2 / s);

[0155] —Water level difference between upstream and downstream (m).

[0156] ⑤ Calculation of the depth of scour at the end of the ocean canal

[0157] The calculation formula is:

[0158]

[0159] In the formula: d m — Depth of riverbed scouring at the end of the seawall (m);

[0160] q m —Seawall terminal unit width flow (m 2 / s);

[0161] [v0]—Permissible non-scouring velocity (m / s) for riverbed soil conditions;

[0162] h m —Depth of the riverbed at the end of the canyon (m).

[0163] ⑥ Calculation results

[0164] The results of the energy dissipation and shock protection calculations are summarized in Table 6.

[0165] Table 6. Calculation Results for Energy Dissipation and Shock Protection

[0166]

[0167] As shown in Table 6, when the reservoir water level is above 1727.00m (normal storage level), under the 20-year and 50-year return periods, the downstream water depth is greater than the post-jump water depth, resulting in a submerged hydraulic jump downstream.

[0168] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A flooded subgrade structure of the kind referred to above, characterised in that: The main body of the roadbed consists of backfilled gravel and soil and slope protection; below the pavement structure layer (1) is the roadbed backfill area (2), which is composed of backfilled gravel and soil, and the overflow channel (5) is set on the side of the roadbed with stable geological conditions; a high-pressure jet grouting anti-seepage wall (4) is set at the center of the roadbed, and the bottom of the high-pressure jet grouting anti-seepage wall (4) extends to the bedrock; the upstream and downstream slopes of the roadbed are protected by concrete beams (9) and gabion stone cage slope protection (8).

2. The overflow-style waterlogged roadbed structure of claim 1, wherein: The lower part of the overflow channel (5) is an integrally consolidated grouting layer (7).

3. The overflow waterlogged roadbed structure according to claim 1, characterized by: The overflow channel (5) adopts a free overflow weir structure, and the inlet elevation of the overflow channel is consistent with the design normal water level.

4. The overflow infiltration structure of claim 1, wherein: The overflow channel (5) consists of a diversion channel section (51), a culvert section (52), a spillway section (53), and a stilling basin section (54) connected in sequence.

5. The overflow infiltration structure according to claim 4, wherein: The diversion channel section (51) is a rectangular open channel with retaining walls on the side walls, forming an integral structure; the bottom slab structure is a C15 concrete cushion layer + C25 concrete, with a cushion layer thickness of 10cm and a C25 concrete thickness of 80cm, located upstream of the roadbed. The culvert section (52) is a rectangular culvert with a reinforced concrete structure, a thickness of 80cm, and a C15 concrete cushion layer on the bottom slab.

6. The overflow infiltration structure of claim 4, wherein: The drainage channel section (53) is a downward slope with a gradient of 1:2.

5. The bottom plate is provided with a C15 concrete cushion layer and the side piers are retaining walls.

7. The overflow infiltration structure of claim 4, wherein, The stilling basin section (54) adopts a bottom flow energy dissipation type stilling basin.

8. The overflow infiltration structure of claim 4, wherein: The upstream and downstream slopes of the roadbed are 1:

2.

9. The overflow infiltration structure of claim 4, wherein: The thickness of the high-pressure jet grouting anti-seepage wall (4) is 60cm.

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