Highway structure on landslide body and collaborative design method of highway maintenance and river discharge

Abstract

The present invention relates to the technical field of disaster prevention and mitigation engineering, specifically to a highway structure on a landslide body, a highway maintenance and a coordinated design method for river channel discharge, the method comprising: setting a rockfall chute, a fill roadbed road, and a landslide lake discharge chute in sequence from the foot of the slope to the far end of the landslide body along the cross-sectional direction of the road; the width of the rockfall chute conforms to the cumulative Weibull probability function distribution, and the geometric parameters of the rockfall chute satisfy the corresponding functional relationship; the cross-sectional form of the discharge chute is an inverted trapezoid, and the geometric parameters of the discharge chute satisfy the corresponding functional relationship; the geometric parameters of the fill roadbed satisfy the corresponding functional relationship; the sum of the width of the rockfall chute, the bottom width of the fill roadbed, and the top width of the discharge chute is less than the total width from the foot of the slope to the far end of the landslide body along the cross-sectional direction of the road. The present invention solves the practical problems that the existing post-disaster highway restoration design focuses on single road repair, lacks dynamic changes in post-earthquake rockfall, and is difficult to comprehensively consider the discharge of the landslide body.

Description

Technical Field

[0001] The invention relates to the technical field of disaster prevention and reduction engineering, in particular to a highway structure on a dam body and a coordinated design method for highway maintenance and river discharge. Background Art

[0002] In western China, especially the Qinghai-Tibet Plateau, due to strong crustal movement, tectonic changes and late erosion, the geological conditions and geomorphic features in this area show the characteristics of large height difference, strong variability and high complexity, forming a typical "high mountain valley" landform. For example, the Himalayas, Kunlun Mountains and other mountain systems often have a slope of more than 30°, and in some areas the slope can reach more than 50°. On the other hand, the Qinghai-Tibet Plateau is located in the center of the Asian seismic belt, where earthquakes are frequent and of high magnitude, especially in the Himalayas, Kunlun Mountains and Qilian Mountains on the plate collision zone. Data show that thousands of weak earthquakes occur in the above-mentioned areas every year, and the frequency of strong earthquakes is also relatively high. Therefore, the huge energy released by earthquakes can easily lead to instantaneous instability of the mountain. In addition, due to the steep terrain and complex rock structure, "collapse (collapse), sliding (landslide), flow (mudslide)" phenomena are extremely common, and can trigger hydrological disasters such as barrier lakes.

[0003] As the country strengthens the construction of transportation and water conservancy projects, mountain roads and river systems often face tremendous pressure for post-disaster recovery. How to scientifically and rationally design river discharge while ensuring smooth highway traffic has become a key technical issue in mountain roads and water conservancy projects.

[0004] A barrier specifically refers to a water retaining body similar to a dam that is formed in a valley due to geological disasters such as mountain collapse, landslide, and mud-rock flow, which temporarily blocks a river. The barrier prevents the upstream water from continuing to flow downstream, and the water begins to accumulate in front of the barrier, forming a gradually expanding reservoir-like lake over time. The speed of water accumulation and the degree of water level rise are affected by many factors, including precipitation, upstream water flow, and the stability of the barrier structure. Traditional methods for preventing and controlling barriers mainly include reducing the threat of barriers to the downstream through artificial reinforcement, diverting water flow, and building spillways.

[0005] Existing post-disaster highway restoration designs also focus on the single repair of roads, usually taking simple reinforcement or excavation treatments, and lacking special designs for geological disasters such as landslide dynamic changes and landslide dams, resulting in repeated road closures or inability to quickly restore traffic during traffic restoration. Highway and river design have long been planned and implemented by the transportation department and water conservancy department respectively. Especially when highways and rivers are intertwined, the lack of coordination between the two is particularly prominent. Therefore, after an earthquake, the design coordination of highways and rivers is particularly important.

[0006] In summary, there is an urgent need to propose a collaborative design method that can simultaneously optimize highway maintenance and river discharge design, which is of great significance for post-earthquake traffic restoration and disaster reduction in mountainous canyon areas. Summary of the invention

[0007] The purpose of the present invention is to provide a highway structure on a dam body and a coordinated design method for highway maintenance and river discharge, which is suitable for highway maintenance on a dam body formed by high-level landslides induced by earthquakes in mountainous canyons.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] In a first aspect, the present invention provides a method for collaboratively designing road maintenance and river discharge on a dam body, comprising the following steps:

[0010] S1. Along the cross-section of the road, from the foot of the slope to the far end of the dam, a rockfall chute, fill roadbed, and dammed lake spillway are set up in sequence;

[0011] S2. Considering the earthquake effect, the width of the rockfall chute W tr It conforms to the cumulative Weibull probability function distribution, and the geometric parameters of the rockfall trough satisfy the following function:

[0012]

[0013]

[0014] In the formula, P ( W tr ) is the cumulative distribution probability of the distance of rockfall from the slope foot under earthquake action, ranging from 0 to 100%; Min[ P ( W tr )] is the minimum allowed cumulative distribution probability; H tr is the depth of the rockfall chute;

[0015] S3. The cross-section of the discharge trough is an inverted trapezoid, and the geometric parameters of the discharge trough satisfy the following function:

[0016]

[0017]

[0018] In the formula, V s The approximate amount of earth excavation for the spillway; L u is the length of the top of the longitudinal section of the dam body; α b is the longitudinal slope of the bottom of the spillway; α u is the longitudinal slope of the top of the spillway; is the bottom width of the spillway; The minimum width of the bottom of the spillway excavated to be limited by mechanical equipment; H sc The excavation depth of the spillway; Excavate the slope for both sides of the spillway; is the internal friction angle of the soil of the dam body; min( V s ) is the minimum amount of earth excavation permitted;

[0019] S4. The geometric parameters of the fill roadbed satisfy the following function:

[0020]

[0021] In the formula, W r is the width of the top surface of the roadbed; H r is the roadbed height; α r is the slope of the roadbed; is the internal friction angle of the dam body soil after compaction;

[0022] S5. The width of the rockfall chute, the bottom width of the fill roadbed, and the top width of the spillway chute meet the following relationship:

[0023]

[0024] In the formula, W It is the total width from the foot of the slope to the far end of the dam along the cross-section of the road.

[0025] In a second aspect, the present invention further provides a highway structure on a landslide dam, which is designed using the above-mentioned collaborative design method for highway maintenance and river discharge on a landslide dam.

[0026] As a preferred technical solution of the present invention, the fill roadbed is arranged on the dam body.

[0027] As a preferred technical solution of the present invention, the bottom elevation of the fill roadbed is not lower than the top elevation of the spillway.

[0028] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0029] 1. The collaborative design method for road maintenance and river discharge on a landslide dam according to the present invention solves the practical problems that the existing post-disaster highway restoration design focuses on single road repair, lacks consideration of the dynamic changes of post-earthquake rockfall, and is difficult to comprehensively consider the discharge of the landslide dam;

[0030] 2. The collaborative design method for maintaining highway accessibility and river discharge on a landslide dam described in the present invention performs calculations based on corresponding geometric parameters of the set building structures, corresponding soil parameters of the landslide dam, and consideration of actual construction workload, and has strong operability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a flow chart of the coordinated design method for highway maintenance and river discharge on the dam body;

[0032] Figure 2 It is a schematic diagram of the structure of rockfall trough, fill roadbed and spillway of barrier lake in high mountain canyon area;

[0033] Figure 3 This is a schematic diagram of the relative frequency and cumulative frequency of the distance between rockfall and the slope foot under earthquake action;

[0034] Figure 4 The geometric diagram of the longitudinal section and cross section of the spillway. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with test examples and specific implementation methods. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0036] Unless otherwise specified, in the description of the specific embodiments of the present invention, the terms indicating the orientation or position relationship such as "up", "down", "left", "right", "center", "inside", "outside", etc. are all expressions based on the orientation or position relationship shown in the drawings, or are the orientation or position relationship when the invented product / equipment / device is usually used. These terms of orientation or position relationship are only for the convenience of describing the scheme of the present invention or simplifying the description in the specific embodiments, so as to facilitate the technicians to quickly understand the scheme, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the present invention.

[0037] In addition, if the terms "horizontal", "vertical", "overhanging", "parallel" and the like appear, it does not mean that the corresponding devices / components / elements are required to be absolutely horizontal or vertical or overhanging or parallel, but may be slightly tilted or have deviations. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but may be slightly tilted. Alternatively, it can be simplified to mean that the corresponding devices / components / elements are set in directions such as "horizontal", "vertical", "overhanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its role in the scheme of the present invention.

[0038] In addition, the expressions “first”, “second”, “third”, etc., which appear in the terms, are merely used to distinguish the description of the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0039] In addition, in the description of the embodiments of the present invention, "several", "plurality" and "a number" represent at least 2. It can be any number such as 2, 3, 4, 5, 6, 7, 8, 9, and even more than 9.

[0040] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threading, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0041] In the related technologies, the existing post-disaster highway restoration design also focuses on the single repair of the road, usually adopting simple reinforcement or excavation treatment, lacking special design for geological disasters such as landslide dynamic changes and dams. At the same time, the design of highways and rivers has long been planned and implemented by the transportation department and the water conservancy department respectively. Especially when highways and rivers are intertwined, the lack of coordination between the two makes it difficult to keep the highway open and face subsequent secondary disasters. For this reason, the technical solution of this application was produced, and the following is combined with Figures 1 to 4 To elaborate.

[0042] Example 1

[0043] like Figure 1As shown, the method for collaboratively designing highway maintenance and river discharge on a dam body of the present invention comprises the following steps:

[0044] S1, such as Figure 2 As shown, along the cross-section direction of the road, from the foot of the slope to the far end of the dam body, the rockfall chute, the fill roadbed and the dammed lake spillway are arranged in sequence.

[0045] The rock chute is responsible for intercepting and collecting falling rocks, preventing landslides and falling rocks from damaging the roads, buildings or facilities below, and guiding the falling rocks to a safe area for subsequent cleaning and maintenance.

[0046] The fill roadbed is responsible for maintaining the accessibility of the highway after the original road section is covered by the landslide. After the earthquake, there is a large amount of accumulated earth and stone in the landslide body and the surrounding area, which is convenient for filling engineering and reducing the occupation of the waste slag site.

[0047] The spillway is used to discharge flood water, guide the water to flow downward, control the water level of the impounded lake within a safe range, and prevent the lake from overflowing the embankment and causing disasters. At the same time, while avoiding the risk of dam break, it also directs the flood to the downstream safe area, reducing the threat to downstream rivers and facilities.

[0048] S2. Considering the earthquake effect, the width of the rockfall chute W tr It conforms to the cumulative Weibull probability function distribution, and the geometric parameters of the rockfall trough satisfy the following function:

[0049]

[0050]

[0051] In the formula, P ( W tr ) is the cumulative distribution probability of the distance of rockfall from the slope foot under earthquake action, ranging from 0 to 100%; Min[ P ( W tr )] is the minimum allowed cumulative distribution probability; H tr is the depth of the rockfall trough.

[0052] Among them, the reason why the width of the rockfall trough conforms to the cumulative Weibull probability function is that after the earthquake, due to the large-scale landslides that occurred along the side slopes and the accumulation of dam bodies, the slope as a whole has been in a more stable state. Under the action of aftershocks, the slope is more likely to suffer from collapse and rockfall disasters. Through the shaking table test of the slope rockfall model, the relative frequency ratio of rockfalls at a distance from the slope foot was statistically analyzed for rocks of different sizes and shapes, different slope types, and different earthquake types (different peak accelerations, different seismic waves).

[0053] like Figure 3 As shown in the figure, the relative frequency ratio of the distance between rockfall and the slope foot under earthquake action is skewed, which can be described by the two-parameter Weibull distribution function, namely:

[0054]

[0055] In the formula, x refers to a non-negative real number, λ refers to the shape parameter in the two-parameter Weibull distribution function, θ Refers to the scale parameter in the two-parameter Weibull distribution function.

[0056] Then the corresponding cumulative Weibull distribution function can be written as:

[0057]

[0058] through Figure 3 Statistical data fitting, λ , θ They are 4.31 and 0.71 respectively.

[0059] Furthermore, the cumulative Weibull distribution function P ( x ) to solve the inverse function, and then we can get the width of the rockfall trough. W tr The function expression of .

[0060] The reason why the geometric parameters of the rockfall trough conform to the above function is that P ( W tr ) refers to the cumulative distribution probability of the distance of falling rocks from the slope foot under earthquake action, ranging from 0 to 100%. P ( W tr ) value determines the width of the rockfall chute. This value can be selected by engineering personnel according to the actual situation of rockfall on site, and provides modification space and reference for the subsequent setting of fill roadbed and flood discharge chute width. In addition, the depth of the rockfall chute is set H tr ≥ W tr , mainly to enable the rockfall chute to provide a higher rockfall collection capacity.

[0061] S3. The cross-section of the discharge trough is an inverted trapezoid, and the geometric parameters of the discharge trough satisfy the following function:

[0062]

[0063]

[0064] In the formula,V s The approximate amount of earth excavation for the spillway; L u is the length of the top of the longitudinal section of the dam body; α b is the longitudinal slope of the bottom of the spillway; α u is the longitudinal slope of the top of the spillway; is the bottom width of the spillway; The minimum width of the bottom of the spillway excavated to be limited by mechanical equipment; H sc The excavation depth of the spillway; Excavate slopes on both sides of the spillway; is the internal friction angle of the soil of the dam body; min( V s ) is the minimum allowable excavation volume.

[0065] The reasons why the cross-section of the spillway is inverted trapezoidal are:

[0066] (1) Due to time and construction conditions, the selected discharge section should have a certain initial flow capacity with the smallest excavation volume possible to lower the reservoir water level in advance.

[0067] (2) The discharge section can be continuously deepened and widened under the action of water flow, thus accelerating the rate of water level reduction.

[0068] (3) For loose materials and a long cross-river length, a wide and shallow section should be selected; for blocks of stone and a short cross-river length, a narrow and deep section should be selected.

[0069] Taking all factors into consideration, the inverted trapezoidal sluiceway has a simple cross-section, is easy to excavate and shape, and can meet the above requirements. Figure 2 and Figure 4 As shown in the upper right picture.

[0070] The reason why the geometric parameters of the discharge trough satisfy the above function is:

[0071] (1) If Figure 4 As shown in the figure, the excavation volume of the spillway V s The calculation can be roughly performed according to its geometric diagram.

[0072] (2) After excavation by mechanical equipment, the spillway trough must have a certain width dimension. Therefore, according to the specific conditions of the excavation equipment, there is a minimum bottom width of the spillway trough.

[0073] (3) The spillway needs to be of a certain depth to have water flow capacity, so the depth of the spillway .

[0074] (4) To ensure smooth water flow through the spillway, the longitudinal slope of the bottom of the spillway should be α b Should not be less than the longitudinal slope of the top of the dam α u .

[0075] (5) The excavated slopes on both sides of the inverted trapezoidal spillway should be self-stable. Should be smaller than the internal friction angle of the dam body soil itself .

[0076] (6) Due to the excavation capacity of the excavation machinery and the number of excavation machinery and equipment, there must be an upper limit to the amount of earth that can be excavated. Therefore, there are constraints in actual projects, namely .

[0077] S4. The geometric parameters of the fill roadbed satisfy the following function:

[0078]

[0079] In the formula, W r is the width of the top surface of the roadbed; H r is the roadbed height; α r is the slope of the roadbed; It is the internal friction angle of the dam body soil after compaction.

[0080] The reason why the geometric parameters of the fill roadbed satisfy the above function is:

[0081] (1) According to the Highway Engineering Technical Standard JTG B01-2014, when a Class IV highway uses a single lane, the lane width should be 3.5m; at the same time, the Class IV lane uses an earth shoulder with a width of 0.5m. As a temporary road to ensure traffic, it is easy to construct while ensuring traffic capacity. It is appropriate to use the Class IV highway as a standard reference for construction. Therefore, the width of the top surface of the roadbed of the temporary highway is W r ≥4.0.

[0082] (2) According to the Highway Roadbed Design Specifications JTG D30-2015, when the slope height is not more than 8m, the slope does not need to be stepped, that is, the cross section of the roadbed is trapezoidal, which is simple and easy to construct, and meets the practicality and temporary nature of the roadbed. H r ≤8.0.

[0083] (3) According to the Highway Roadbed Design Code JTG D30-2015, the slope of the submerged embankment below the design water level should not be steeper than 1:1.75. Considering the actual situation that the dam is greatly affected by water, the roadbed slope should meet the requirements of this code. In addition, the roadbed slope needs to be self-stable, so the slope of the roadbed slope should be less than the internal friction angle of the dam soil after compaction. , the soil compaction degree should meet the compaction standard of the fourth-level highway subgrade in the "Highway Subgrade Design Code" JTG D30-2015. Therefore, if the above two requirements are met, .

[0084] S5. The width of the rockfall chute, the bottom width of the fill roadbed, and the top width of the spillway chute meet the following relationship:

[0085]

[0086] In the formula, W It is the total width from the foot of the slope to the far end of the dam along the cross-section of the road.

[0087] According to the actual situation, the sum of the rockfall chute width, the fill roadbed bottom width and the spillway top width should be designed within the total width range.

[0088] The method for collaboratively designing highway maintenance and river discharge on a landslide dam described in this embodiment solves the practical problems that existing post-disaster highway restoration designs focus on single road repair, lack the dynamic changes of post-earthquake rockfall, and have difficulty in comprehensively considering the discharge of landslide dams.

[0089] The method for collaborative design of highway maintenance and river discharge on a landslide dam described in this embodiment performs calculations based on corresponding geometric parameters of the set building structures, corresponding soil parameters of the landslide dam, and consideration of actual construction workload, and has strong operability.

[0090] Example 2

[0091] like Figure 2 As shown, a highway structure on a landslide dam described in the present invention is designed using the collaborative design method for highway maintenance and river discharge on a landslide dam described in Example 1.

[0092] In some optional embodiments, the fill roadbed is arranged on the dam body, and the elevation of the bottom of the fill roadbed is not lower than the elevation of the top of the spillway.

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A collaborative design method for road maintenance and river discharge on a dam body, characterized in that: The following steps are involved: S1. Along the cross-section of the road, from the foot of the slope to the far end of the dam, a rockfall chute, fill roadbed, and dammed lake spillway are set up in sequence; S2, width of rockfall chute W tr It conforms to the cumulative Weibull probability function distribution, and the geometric parameters of the rockfall trough satisfy the following function: In the formula, P ( W tr ) is the cumulative distribution probability of the distance of rockfall from the slope foot under earthquake action, ranging from 0 to 100%; Min[ P ( W tr )] is the minimum allowed cumulative distribution probability; H tr is the depth of the rockfall chute; S3. The cross-section of the discharge trough is an inverted trapezoid, and the geometric parameters of the discharge trough satisfy the following function: In the formula, V s The excavation volume of the spillway; L u is the length of the top of the longitudinal section of the dam body; α b is the longitudinal slope of the bottom of the spillway; α u is the longitudinal slope of the top of the spillway; is the bottom width of the spillway; The minimum width of the bottom of the spillway excavated to be limited by mechanical equipment; H sc The excavation depth of the spillway; Excavate the slope for both sides of the spillway; is the internal friction angle of the soil of the dam body; min( V s ) is the minimum amount of earth excavation permitted; S4. The geometric parameters of the fill roadbed satisfy the following function: In the formula, W r is the width of the top surface of the roadbed; H r is the roadbed height; α r is the slope of the roadbed; is the internal friction angle of the dam body soil after compaction; S5. The width of the rockfall chute, the bottom width of the fill roadbed, and the top width of the spillway chute meet the following relationship: In the formula, W It is the total width from the foot of the slope to the far end of the dam along the cross-section of the road.

2. A highway structure on a dam body, characterized in that: The design is carried out using the collaborative design method for maintaining highway accessibility and river discharge on a landslide body as described in claim 1.

3. The highway structure on the dam body according to claim 2, characterized in that: The fill roadbed is set on the dam body.

4. The highway structure on the dam body according to claim 2, characterized in that: The bottom elevation of the fill roadbed shall not be lower than the top elevation of the spillway.

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