Roadbed slope surface protection structure of multi-stage small platform and construction method

Abstract

The invention belongs to the technical field of road slope engineering, and particularly relates to a roadbed slope surface protection structure of a multi-stage small platform and a construction method. The slope surface protection structure is located on the surface of a side slope body and comprises platform parts, and a platform ditch is formed in a platform of each platform part; each torrent groove part is provided with a torrent groove, and the torrent grooves are communicated with the upper-stage platform ditch and the lower-stage platform ditch; the platform part and the torrent groove part are formed by compacting modified soil; each platform part comprises a plurality of compaction layers, a reinforced layer is arranged at the bottom of each compaction layer, the length of each reinforced layer is larger than the depth of each compaction layer, and after the reinforced layers are backfilled with modified soil and compacted, the parts, exceeding the compaction layers, of the reinforced layers are reversely wrapped on the compaction layers, so that each platform part is reinforced into a retaining structure similar to a road shoulder wall. The whole slope protection structure has better integrity, can effectively avoid the damage conditions such as landslide of the slope, and greatly improves the stability of the slope.

Description

Technical Field

[0001] The invention belongs to the technical field of highway slope engineering, and specifically relates to a roadbed slope surface protection structure with multiple small platforms and a construction method. Background Art

[0002] During the construction and operation period of highways, the slope surface of roadbed slopes is easily affected by complex factors such as the terrain, geology and hydrological environment. As a result, various types of earth roadbed slopes, stone-filled roadbed slopes and special earth roadbed slopes are prone to loose body collapse, mudslides and water damage. The damage is more obvious under the influence of heavy rainfall, dry-wet cycles, fissure water or infiltration water.

[0003] Traditional slope protection mainly includes plant protection and engineering protection, among which the more mature slope protection methods include skeleton slope protection, mortar-laid stone, face wall, turf laying and spray protection. Specifically, the skeleton slope protection structure is extremely scattered, and the construction quality is difficult to guarantee. In addition, due to its own heavy weight, when the soil below it settles unevenly, a gap will appear between the skeleton structure and the soil below it, so that the skeleton structure cannot be well supported, which will cause local damage to the slope protection. The locally damaged slope will expand the damaged area of ​​the slope under the long-term scouring effect of continuous rainfall or heavy rain, causing the slope soil to be lost and the slope soil structure to become loose, which will lead to gullies and potholes on the slope, destroying the original shape of the slope and ultimately destroying the overall stability of the slope.

[0004] In addition, the height of each level of the existing highway roadbed is usually about 8.0m, and the platform width is usually about 2.0m. The slope is longer, the catchment area is larger, and the scouring capacity of rainwater is greater. Under the action of gravity, rainwater scours the foot of each level of the slope, which can easily lead to loosening and collapse of the slope surface.

[0005] In addition, traditional slope protection projects require a large number of skilled workers, have high labor costs, low construction efficiency, long construction period, difficult to ensure construction quality, and high construction safety risks; and for areas where stone is scarce, rubble protection and masonry protection require quarrying, which has low efficiency and is not economical or environmentally friendly.

[0006] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Invention content

[0007] The purpose of the invention is to provide a roadbed slope surface protection structure with multiple small platforms and a construction method to at least solve the above-mentioned problems existing in the prior art.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A roadbed slope surface protection structure with multiple small platforms, the slope surface protection structure is located on the surface of the slope body, and the slope surface protection structure includes:

[0010] A platform part, wherein a plurality of platform parts are arranged on the slope surface of the side slope, wherein the top surface of the platform part is a horizontally extending platform, and a platform groove is arranged on the platform of each platform part;

[0011] A rapid flow trough portion, wherein a plurality of rapid flow trough portions are arranged between two adjacent platform portions, the rapid flow trough portions extend along the inclined surface of the slope, and a rapid flow trough is arranged on each rapid flow trough portion, and the rapid flow trough connects the upper and lower platform grooves;

[0012] The platform part and the rapids trough part are both formed by compacting modified soil;

[0013] The platform portion includes multiple compacted layers, and the platform ditch is arranged on the topmost compacted layer in the platform portion. A reinforcement layer is arranged at the bottom of each compacted layer, and the length of the reinforcement layer is greater than the depth of the compacted layer. After the modified soil is backfilled on the reinforcement layer and compacted, the part of the reinforcement layer that exceeds the compacted layer is reversely wrapped on the compacted layer, so that each platform portion is reinforced into a retaining structure similar to a shoulder wall.

[0014] The roadbed slope surface protection structure with multiple small platforms as described above is preferably formed by adding cement in an amount of 10% to 20% of the mass of the plain soil to the plain soil and uniformly stirring the mixture to form the modified soil.

[0015] In the roadbed slope surface protection structure with multiple small platforms as described above, preferably, the reinforcement layer is a glass fiber grid, and the reinforcement layer is fixedly connected to the compaction layer by U-shaped nails.

[0016] For the roadbed slope protection structure with multiple small platforms as described above, preferably, the vertical drop between the platforms of two adjacent platform parts is controlled to be less than 4m, and the platform width of the platform part is controlled to be within the range of 1-1.5m.

[0017] For the roadbed slope surface protection structure with multiple small platforms as described above, preferably, a drainage ditch is provided at the bottom of the slope surface protection structure, and the rapids trough at the bottom layer is connected to the drainage ditch.

[0018] A construction method for a roadbed slope surface protection structure with multiple small platforms, the construction method is for the construction method of the roadbed slope surface protection structure with multiple small platforms; the construction method comprises the following steps:

[0019] Step 1: First, conduct a re-survey of the guide wire piles and leveling points to determine the longitudinal and transverse axes of the road section and the plane position of the slope surface, and then divide the roadbed slope into sections, and first excavate the soil where the construction platform is required on the slope surface;

[0020] Step 2, constructing compacted layers step by step to form a first-level platform portion. Specifically, when constructing a compacted layer, first lay a reinforced layer of a grid structure, and fix the reinforced layer with U-shaped nails;

[0021] Step 3, then backfill the modified soil layer by layer on the reinforced layer, and compact it layer by layer to form a compacted layer. After the compaction of one compacted layer is completed, the reinforced layer of the extra compacted layer is reversely wrapped on the compacted layer, and U-shaped nails are driven into the reinforced layer of the reversed part for fixing; a platform ditch is constructed on the topmost compacted layer; steps 2-3 are repeated until the construction of the multi-level platform part is completed;

[0022] Step 4, constructing a plurality of rapid flow troughs between two adjacent platform parts, and constructing a rapid flow trough in each rapid flow trough part, connecting the two adjacent platform grooves through the rapid flow trough; and constructing a drainage ditch at the bottom of the slope;

[0023] Step 5, after the construction and maintenance of the platform ditch, rapids trough and drainage ditch are completed, the humus, fertilizer, water retaining agent and grass seed mixture are evenly mixed, and grass seeds are mixed on part of the slope between the platform part and the rapids trough part, and the slope is continuously watered and maintained.

[0024] The construction method of the roadbed slope protection structure with multiple small platforms as described above, preferably, the sizes of the platform ditch, rapids trough and drainage ditch are appropriately selected according to the design value of the water-passing cross-sectional area;

[0025] The design formula of the water flow cross-sectional area W is as follows:

[0026] Total rainfall flow per unit length on the platform:

[0027]

[0028] Where: x is the horizontal position on the slope, that is, the horizontal distance from the current point to the origin along the horizontal direction when the edge of one side of the platform is taken as the origin; q is the rainfall intensity; l is the horizontal unit length of the step;

[0029] Water flow rate on slope:

[0030]

[0031] Where: v w is the flow velocity, i is the hydraulic slope, c is the Xie Cai coefficient, and R is the hydraulic radius;

[0032] The total rainfall flow per unit length of the cross-sectional area is divided by the water flow rate, specifically:

[0033]

[0034] In the construction method of the roadbed slope protection structure with multiple small platforms as described above, preferably, when constructing the topmost compacted layer of the platform part, a reinforcement layer is first laid, and then modified soil is backfilled on the reinforcement layer, and a steel section or round steel of a set size is selected as a forming mold, and the forming mold is pressed into the loose modified soil that has not been compacted after backfilling, and then the modified soil around the forming mold is compacted, and then the forming mold is taken out to form a platform groove, and the reinforcement layer is wrapped on the topmost compacted layer, and finally the surface of the platform groove is mortared.

[0035] In the construction method of the roadbed slope surface protection structure of the multi-level small platform as described above, preferably, when constructing the topmost compacted layer of the platform part, a lightweight prefabricated component is selected as the platform ditch, a reinforcement layer is first laid, and then modified soil is backfilled on the reinforcement layer, and the lightweight prefabricated components are spliced ​​to form a platform ditch, and modified soil is backfilled and compacted on both sides of the platform ditch to fix the position of the platform ditch, and finally the reinforcement layer is wrapped on the topmost compacted layer.

[0036] In the construction method of the roadbed slope protection structure of the multi-level small platform as described above, preferably, in step 4, when constructing the rapid flow trough and the rapid flow trough, the soil where the rapid flow trough is to be constructed is first excavated, and then the stirred modified soil is backfilled, and the forming mold of the rapid flow trough is pressed into the loose modified soil, or lightweight prefabricated components are spliced ​​to form the rapid flow trough;

[0037] Then compact the modified soil on both sides of the rapid trough. If a forming mold is used to form the rapid trough, remove the forming mold after compacting the modified soil, and apply mortar to the rapid trough and its vicinity to complete the rapid trough.

[0038] Beneficial effects:

[0039] In the slope protection structure, modified soil and reinforced layer are used to make the platform part, and the reinforced layer with a grid structure is laid at the bottom of each compacted layer in the platform part, and the reinforced layer is reversely wrapped on the compacted layer; the platform part not only plays the role of blocking rain and sealing water, but also plays a role of better supporting the foot of each slope body, thereby improving the waterproof performance of the slope surface and the overall structural strength, and making the entire slope protection structure have better integrity, which can effectively avoid damage such as landslides on the slope and greatly improve the stability of the slope.

[0040] This slope protection structure can not only better prevent water from penetrating into the slope and eroding the slope structure, but also ensure that the density of the platform and the rapids trough is not much different from the surrounding structure. It can also effectively prevent uneven settlement of the slope surface due to excessive gravity difference. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings constituting part of the present application are used to provide a further understanding of the invention. The exemplary embodiments and descriptions of the invention are used to explain the invention and do not constitute an improper limitation on the invention. Among them:

[0042] Figure 1 A schematic diagram of a roadbed slope protection structure with multiple small platforms according to an embodiment of the present invention;

[0043] Figure 2 A side view of a roadbed slope protection structure with multiple small platforms according to an embodiment of the present invention;

[0044] Figure 3 A flow chart of a construction method for a roadbed slope surface protection structure with multiple small platforms is created for an embodiment of the present invention.

[0045] In the figure: 1. platform part; 11. platform ditch; 12. reinforcement layer; 13. U-shaped nails; 2. rapids trough part; 21. rapids trough; 3. drainage ditch. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present invention, including the type of curing agent for modified soil, changes in the dosage ratio, etc.

[0047] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention. The terms "connected" and "connected" used in the present invention should be understood in a broad sense. For example, they can be fixedly connected or detachably connected; they can be directly connected or indirectly connected through intermediate components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0048] The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0049] According to the specific embodiments of the present invention, Figure 1-3As shown, the present invention provides a roadbed slope surface protection structure with multiple small platforms, the slope surface protection structure is located on the surface of the slope body, and the slope surface protection structure includes:

[0050] The platform part 1 has multiple levels of platform parts 1 arranged on the slope surface. The top surface of the platform part 1 is a horizontally extending platform. A platform groove 11 is arranged on the platform of each platform part 1 .

[0051] A plurality of rapid flow trough portions 2 are arranged between two adjacent platform portions 1 . The rapid flow trough portions 2 extend along the inclined surface of the slope. A rapid flow trough 21 is arranged on each rapid flow trough portion 2 . The rapid flow trough 21 connects the upper and lower platform grooves 11 .

[0052] The platform part 1 and the rapids trough part 2 are both formed by compacting modified soil.

[0053] The platform portion 1 includes multiple compacted layers, and the platform ditch 11 is arranged on the topmost compacted layer in the platform portion 1. A reinforcement layer 12 is arranged at the bottom of each compacted layer. The length of the reinforcement layer 12 is greater than the depth of the compacted layer. After the modified soil is backfilled and compacted on the reinforcement layer 12, the part of the reinforcement layer 12 that exceeds the compacted layer is reversely wrapped on the compacted layer, so that each platform portion 1 is reinforced into a retaining structure similar to a shoulder wall.

[0054] In the slope surface protection structure, the modified soil has better compressive strength, shear strength and better anti-penetration and waterproof performance, and the density of the modified soil and the plain soil is not much different. The modified soil is used to make the platform part 1 and the rapids trough part 2. First, the platform part 1 and the rapids trough part 2 can prevent rainwater from penetrating into the interior of the slope, and play a good role in blocking rain and sealing water; secondly, the platform part 1 reinforced by the modified soil and the reinforcement layer 12 is reinforced into a supporting structure similar to the shoulder wall, which can play a good supporting role at each level of the slope surface. That is, the slope surface protection structure can not only make the slope surface better prevent water from penetrating into the slope and eroding the slope structure, but the density of the platform part 1 and the rapids trough part 2 is not much different from the surrounding structures, and it can also well avoid uneven settlement of the slope surface due to excessive gravity difference.

[0055] In addition, laying a reinforced layer 12 of a grid structure at the bottom of each compacted layer and wrapping the reinforced layer 12 around the end of the compacted layer can effectively prevent soil erosion on the slope, which not only greatly enhances the overall structural strength of the slope protection structure, but also improves the shear resistance of the entire slope protection structure; it also makes the slope more resistant to erosion, which in turn strengthens the structural performance of the toe of each layer of the slope, so that the toe of each layer of the slope can be better supported by the platform portion 1 having a similar function to a shoulder wall.

[0056] Since the toe of the slope is subject to continuous impact from flowing water, it is easy to be damaged. If the toe is made of concrete, stone or other materials, although the structural strength of the toe can be improved, the density of the toe is greater than that of the surrounding materials. The large density difference makes it more likely that the toe will experience uneven settlement, which will increase the probability of local damage to the slope surface, thereby reducing the long-term stability and durability of the slope.

[0057] The slope protection structure of this invention completely abandons the existing technical concepts of skeleton slope protection, stone masonry and other structures in traditional slope protection. The platform part 1 is made of modified soil and a reinforced layer 12 of a grid structure. The reinforced layer 12 of the grid structure is laid on the bottom of each compacted layer in the platform part 1, and the reinforced layer 12 of the grid structure is reversely wrapped on the compacted layer; the platform part 1 not only plays the role of blocking rain and sealing water, but also plays a role of better supporting the foot of each slope body, thereby improving the waterproof performance of the slope surface and the overall structural strength, and making the entire slope protection structure have better integrity, which can effectively avoid damage such as landslides on the slope and greatly improve the stability of the slope.

[0058] In this embodiment, the modified soil is formed by mixing cement with the original soil excavated in situ. Specifically, the modified soil is formed by adding 10% to 20% of the mass of the original soil into the original soil and stirring evenly. In one embodiment of the present application, different proportions of cement can be added to the original soil of different properties in different regions and stirred evenly, so that the modified soil has better compressive strength, shear strength and better anti-seepage and anti-scouring properties.

[0059] In other embodiments, the modified soil may also be combined with the plain soil using lime or other solidifying agents.

[0060] Specifically, during the mixing process of cement and plain soil, a sprinkler truck is used to supply water, and the water volume is controlled manually. After adding a small amount of water, the modified soil is evenly mixed with an excavator; the mixed modified soil is returned to the previously excavated base platform in layers and compacted in layers, with each layer being about 25 cm thick.

[0061] In this embodiment, except for the slope protection structure, the other parts of the slope are compacted with plain soil, and only the slope protection structure part is reinforced with a reinforcement layer 12 of modified soil and a grid structure. On the basis of ensuring better stability of the slope, it can also greatly save construction costs and have better economy.

[0062] The reinforced layer 12 is a glass fiber grid, and the reinforced layer 12 is fixedly connected to the compacted layer by U-shaped nails 13. In one embodiment of the present application, the reinforced layer 12 adopts a glass fiber grid with a tensile strength of 50N, and the reinforced layer 12 is arranged in the compacted layer, and the reinforced layer 12 is reversed on the compacted layer, so that the reinforced layer 12 can be used as a skeleton structure in the platform part 1, and the reversed part of the reinforced layer 12 is covered by the upper compacted layer, which can greatly enhance the integrity of the platform part 1 and improve the overall structural strength of the slope protection structure, so that the slope protection structure has better anti-slip performance.

[0063] The vertical drop between the platforms of two adjacent platform parts 1 is controlled to be less than 4m, and the platform width of the platform part 1 is controlled to be within the range of 1-1.5m. In one embodiment of the present application, by controlling the vertical drop between two adjacent platform parts 1, a multi-level small step structure is formed on the slope surface, which can not only shorten the rainwater scouring path and effectively reduce the scouring energy of rainwater on the slope foot; but also minimize the rainwater from the part between the slope platform part 1 and the rapids trough part 2 entering the interior of the slope.

[0064] A drainage ditch 3 is provided at the bottom of the slope protection structure, and the lowest rapids trough 21 is connected to the drainage ditch 3. In one embodiment of the present application, the drainage ditch 3 is provided at the lowest part of the slope protection structure to divert the water flow and prevent the water flow from gathering at the bottom of the slope protection structure.

[0065] The present application also relates to a construction method for a roadbed slope surface protection structure with multiple small platforms. The construction method is directed to the construction method for the roadbed slope surface protection structure with multiple small platforms. The construction method comprises the following steps:

[0066] Step 1: First, re-survey the guide wire piles and leveling points to determine the longitudinal and transverse axes of the road section and the plane position of the slope surface, and divide the roadbed slope into sections, and first excavate the soil where the construction platform part 1 is required on the slope surface;

[0067] In this embodiment, two small excavators can be used to dig temporary access ramps from both ends of the construction section. A 2.0m to 3.0m wide construction access road is excavated at a position 90cm away from the top of each slope. A 1.0m to 2.0m wide construction access road is excavated every 2.0 to 4.0m in height from the first construction access road. The excavated soil is placed on the top of the roadbed to facilitate the subsequent use of modified soil. The bottom width of each step after excavation is about 1.0 to 1.5m wide, and the excavated platform is at a certain reverse angle to the inside.

[0068] Step 2, constructing compacted layers step by step to form a first-level platform portion 1. Specifically, when constructing a compacted layer, first lay a reinforcement layer 12 of a grid structure, and fix the reinforcement layer 12 with U-shaped nails 13;

[0069] Step 3, then backfill the modified soil layer by layer on the reinforcement layer 12, and compact it layer by layer to form a compacted layer. After the compaction of one compacted layer is completed, the reinforcement layer 12 of the extra compacted layer is reversely wrapped on the compacted layer, and U-shaped nails 13 are driven into the reversed part of the reinforcement layer 12 for fixing; a platform ditch 11 is constructed on the topmost compacted layer; steps 2-3 are repeated until the construction of the multi-level platform part 1 is completed;

[0070] In this embodiment, the thickness of each compacted layer is 50CM. In each compacted layer, the thickness of each backfill modified soil compaction is 25CM, and the backfill is performed in two times, that is, the backfill thickness of the reinforcement layer 12 is 50CM; and before compacting the modified soil, an appropriate amount of water is added to the modified soil to keep the modified soil at a suitable humidity, so that the modified soil has a better compaction effect.

[0071] Step 4, construct a plurality of rapid flow troughs 2 between two adjacent platform portions 1, and construct a rapid flow trough 21 in each rapid flow trough portion 2, connecting the two adjacent platform ditches 11 through the rapid flow trough 21; and construct a drainage ditch 3 at the bottom of the slope;

[0072] In this embodiment, the vertical drop between the platforms of two adjacent platform parts 1 is controlled to be less than 4m, and the platform width of the platform part 1 is controlled to be within the range of 1-1.5m. By controlling the vertical drop between two adjacent platform parts 1, a multi-level small step structure is formed on the slope surface, which can not only shorten the rainwater scouring path and effectively reduce the scouring energy of rainwater on the slope foot; but also can minimize the rainwater from the part between the slope platform part 1 and the rapids trough part 2 entering the interior of the slope.

[0073] Step 5, after the platform ditch 11, the rapid trough 21 and the drainage ditch 3 are constructed and maintained, the humus soil, fertilizer, water retaining agent, and grass seed mixed materials are stirred evenly, and grass seeds are mixed on the partial slope between the platform part 1 and the rapid trough part 2, and the slope is continuously watered and maintained. In this embodiment, a watering truck is used to wet the slope, and after the mixed materials such as humus soil, fertilizer, water retaining agent, and grass seeds are stirred, grass seeds are mixed on each level of the slope surface. The mixed grass seeds are selected from deep roots and shallow roots, legumes and gramineous, foreign and local characteristics for mixed spraying, so that they are evenly sprayed on each level of the slope surface. After the grass seed spraying is completed, the slope is covered with a non-woven fabric to play a role in heat preservation and moisture retention and promoting plant growth. During the period from the germination of plant seeds to the seedlings, watering and maintenance are required to keep the soil moist.

[0074] Select appropriate sizes of the platform ditch 11, rapids trough 21 and drainage ditch 3 according to the design value of the water flow cross-sectional area;

[0075] The design formula for the water flow cross-sectional area W is as follows:

[0076] Total rainfall flow per unit length on platform 1:

[0077]

[0078] Where: x is the horizontal position on the slope, that is, the horizontal distance from the current point to the origin along the horizontal direction when the edge of one side of the platform part 1 is taken as the origin; q is the rainfall intensity; l is the horizontal unit length of the step;

[0079] Water flow rate on slope:

[0080]

[0081] Where: v w is the flow velocity, i is the hydraulic slope, c is the Xie Cai coefficient, and R is the hydraulic radius;

[0082] The total rainfall flow per unit length of the cross-sectional area is divided by the water flow rate, specifically:

[0083]

[0084] In one embodiment of the present application, according to the design reference value of the water flow cross-sectional area calculated by the design formula, the sizes of the platform ditch 11, the rapid flow trough 21 and the drainage ditch 3 suitable for the water flow cross-sectional area can be selected.

[0085] In one embodiment of the present application, the water flow impact reduction effect of the roadbed slope protection structure with multiple small platforms is calculated and analyzed as follows:

[0086] For the case of steady flow of rainwater along the slope, the flow velocity at different heights can be estimated based on the simplified form of the Bernoulli equation under specific conditions. Assume that the water flows from a high point (height h1) to another lower point (height h2), and the pressure of the water flow at the two points can be approximately considered the same (for example, both are connected to the atmosphere), the water flow velocities are v1 and v2 respectively, and the gravitational acceleration is g. According to the law of conservation of energy, the simplified Bernoulli equation can be expressed as:

[0087]

[0088] If the flow velocity at the starting point is known, the flow velocity at different heights can be calculated using the above formula. The calculation formula is:

[0089]

[0090] Assuming that the rainfall intensity q (unit: cm / s) remains unchanged, the total rainfall flow Q per unit width on the step is calculated according to the water flow continuity equation:

[0091]

[0092] Assuming that the initial height is at the top of the slope, the initial velocity can be calculated based on the total rainfall and the water-passing section. The specific formula is:

[0093]

[0094] Substituting formula (3) into formula (6), we can get the speed of rainwater flowing along the slope at any height of the slope. The specific formula is:

[0095]

[0096] Therefore, the expression of water flow impact force at any height of the slope is:

[0097]

[0098] In one embodiment of the present application, according to the design data, the average rainfall intensity q is 0.003 cm / s, the road surface of the two-way two-lane highway is 3.75 m wide, the total height of the slope is 16 m, the height of each step is 4 m, the roughness coefficient n of the asphalt concrete road surface is 0.013, and the road surface slope i of the highway is generally 2.0%.

[0099] It can be obtained that the scouring energy of multi-step water flow per unit area is reduced by 75% compared with that of single-step slope. Therefore, the energy of rainwater scouring the foot of the slope can be reduced, the soil loss at the foot of the slope can be effectively controlled, and the slope will not become steeper due to the hollowing out of the foot of the slope, so that the slope can be kept intact. At the same time, the stable foot of the slope can make the vegetation on the slope grow better, and the vegetation can in turn further stabilize the soil, forming a virtuous circle, which is conducive to maintaining the stability of the entire slope.

[0100] The mechanical parameters of the modified soil were determined by direct shear test and substituted into the following calculation formula of slope stability coefficient:

[0101]

[0102] In the formula, c i l i is the cohesion of the sliding surface of the ith soil block, G i is the gravity of the ith soil block, α i is the internal friction angle of the sliding surface of the ith soil block, is the angle between the normal line on the sliding arc of the ith soil block and the vertical line, K S is the stability coefficient.

[0103] In one embodiment of the present application, the mechanical parameters of the modified soil are measured by direct shear test, and substituted into the stability coefficient calculation formula to calculate whether the stability coefficient of the modified soil meets the standard. After the modified soil stability coefficient is tested to meet the standard, it is put into use in the construction of the slope surface protection structure.

[0104] In one embodiment of the present application, when constructing the topmost compacted layer of the platform portion 1, the reinforcement layer 12 is first laid, and then the modified soil is backfilled on the reinforcement layer 12. A steel section or round steel of a set size is selected as a forming mold, and the forming mold is pressed into the loose modified soil that has not been compacted after backfilling. After the modified soil around the forming mold is compacted, the forming mold is taken out to form the platform groove 11, and the reinforcement layer 12 is wrapped on the topmost compacted layer, and finally the surface of the platform groove 11 is mortared.

[0105] In other embodiments of the present application, when constructing the compacted layer at the top of the platform portion 1, lightweight prefabricated components are selected as the platform trench 11, the reinforcement layer 12 is first laid, and then the modified soil is backfilled on the reinforcement layer 12, and the lightweight prefabricated components are spliced ​​to form the platform trench 11, and the modified soil is backfilled and compacted on both sides of the platform trench 11 to fix the position of the platform trench 11, and finally the reinforcement layer 12 is wrapped around the topmost compacted layer.

[0106] In other embodiments of the present application, when cement, stone or solid waste materials are sufficient, they are used to make lightweight prefabricated components, and the lightweight prefabricated components include: concrete prefabricated components or lightweight concrete prefabricated components or solid waste material-based prefabricated components; at this time, the platform ditch 11 made of lightweight prefabricated components has better structural strength and a longer service life.

[0107] In step 4, when constructing the rapid trough part 2 and the rapid trough 21, first dig out the soil where the rapid trough part 2 needs to be constructed, then backfill the mixed modified soil, and press the forming mold of the rapid trough 21 on the loose modified soil, or use lightweight prefabricated components to splice to form the rapid trough 21 (the manufacturing process of the rapid trough 21 here is consistent with that of the platform ditch 11, which will not be repeated); then compact the modified soil on both sides of the rapid trough 21. If a forming mold is used to form the rapid trough 21, remove the forming mold after compacting the modified soil, and apply mortar to the rapid trough 21 and its vicinity, and complete the manufacturing of the rapid trough part 2.

[0108] It should be understood that the above description is merely exemplary and the embodiments of the present application do not limit this.

[0109] 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, improvements, etc. made within the spirit and principle of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A roadbed slope protection structure with multiple small platforms, characterized in that: The slope protection structure is located on the surface of the slope body, and the slope protection structure includes: A platform part, wherein a plurality of platform parts are arranged on the slope surface of the side slope, wherein the top surface of the platform part is a horizontally extending platform, and a platform groove is arranged on the platform of each platform part; A rapid flow trough portion, wherein a plurality of rapid flow trough portions are arranged between two adjacent platform portions, the rapid flow trough portions extend along the inclined surface of the slope, and a rapid flow trough is arranged on each rapid flow trough portion, and the rapid flow trough connects the upper and lower platform grooves; The platform part and the rapids trough part are both formed by compacting modified soil; The platform portion includes multiple compacted layers, and the platform ditch is arranged on the topmost compacted layer in the platform portion. A reinforcement layer is arranged at the bottom of each compacted layer, and the length of the reinforcement layer is greater than the depth of the compacted layer. After the modified soil is backfilled on the reinforcement layer and compacted, the part of the reinforcement layer that exceeds the compacted layer is reversely wrapped on the compacted layer, so that each platform portion is reinforced into a retaining structure similar to a shoulder wall.

2. The roadbed slope protection structure with multiple small platforms according to claim 1 is characterized in that: The modified soil is formed by adding 10% to 20% of the mass of the raw soil into the raw soil and stirring the mixture uniformly.

3. The roadbed slope protection structure with multiple small platforms according to claim 2 is characterized in that: The reinforcement layer is a glass fiber grid, and the reinforcement layer is fixedly connected to the compaction layer through U-shaped nails.

4. The roadbed slope protection structure with multiple small platforms according to claim 3 is characterized in that: The vertical drop between the platforms of two adjacent platform parts is controlled to be below 4m, and the platform width of the platform part is controlled to be within the range of 1-1.5m.

5. The roadbed slope protection structure with multiple small platforms according to claim 4 is characterized in that: A drainage ditch is arranged at the bottom of the slope protection structure, and the rapids trough at the bottom layer is connected with the drainage ditch.

6. A construction method for a roadbed slope protection structure with multiple small platforms, characterized in that: The construction method is directed to the construction method of the roadbed slope protection structure of the multi-level small platform described in any one of claims 1 to 5; the construction method comprises the following steps: Step 1: First, conduct a re-survey of the guide wire piles and leveling points to determine the longitudinal and transverse axes of the road section and the plane position of the slope surface, and then divide the roadbed slope into sections, and first excavate the soil where the construction platform is required on the slope surface; Step 2, constructing compacted layers step by step to form a first-level platform portion. Specifically, when constructing a compacted layer, first lay a reinforced layer of a grid structure, and fix the reinforced layer with U-shaped nails; Step 3, then backfill the modified soil layer by layer on the reinforced layer, and compact it layer by layer to form a compacted layer. After the compaction of one compacted layer is completed, the reinforced layer of the extra compacted layer is reversely wrapped on the compacted layer, and U-shaped nails are driven into the reinforced layer of the reversed part for fixing; a platform ditch is constructed on the topmost compacted layer; steps 2-3 are repeated until the construction of the multi-level platform part is completed; Step 4, constructing a plurality of rapid flow troughs between two adjacent platform parts, and constructing a rapid flow trough in each rapid flow trough part, connecting the two adjacent platform grooves through the rapid flow trough; and constructing a drainage ditch at the bottom of the slope; Step 5, after the construction and maintenance of the platform ditch, rapids trough and drainage ditch are completed, the humus, fertilizer, water retaining agent and grass seed mixture are evenly mixed, and grass seeds are mixed on part of the slope between the platform part and the rapids trough part, and the slope is continuously watered and maintained.

7. The construction method of the roadbed slope surface protection structure with multiple small platforms according to claim 6 is characterized in that: Select appropriate sizes of the platform ditch, rapids trough and drainage ditch according to the design value of the water flow cross-sectional area; The design formula of the water flow cross-sectional area W is as follows: Total rainfall flow per unit length on the platform: Where: x is the horizontal position on the slope, that is, the horizontal distance from the current point to the origin along the horizontal direction when the edge of one side of the platform is taken as the origin; q is the rainfall intensity; l is the horizontal unit length of the step; Water flow rate on slope: Where: v w is the flow velocity, i is the hydraulic slope, c is the Xie Cai coefficient, and R is the hydraulic radius; The total rainfall flow per unit length of the cross-sectional area is divided by the water flow rate, specifically:

8. The construction method of the roadbed slope surface protection structure with multiple small platforms according to claim 6 is characterized in that: When constructing the compacted layer at the top of the platform, first lay the reinforcement layer, then backfill the modified soil on the reinforcement layer, select steel sections or round steel of a set size as a forming mold, press the forming mold into the loose modified soil that has not been compacted after backfilling, and then compact the modified soil around the forming mold. Then take out the forming mold to form a platform groove, and wrap the reinforcement layer on the topmost compacted layer. Finally, apply mortar to the surface of the platform groove.

9. The construction method of the roadbed slope surface protection structure with multiple small platforms according to claim 6 is characterized in that: When constructing the compacted layer at the top of the platform part, lightweight prefabricated components are selected as the platform trench. The reinforced layer is laid first, and then the modified soil is backfilled on the reinforced layer. The lightweight prefabricated components are spliced ​​to form a platform trench. The modified soil is backfilled and compacted on both sides of the platform trench to fix the position of the platform trench. Finally, the reinforced layer is wrapped on the top compacted layer.

10. The construction method of the roadbed slope surface protection structure with multiple small platforms according to claim 6 is characterized in that: In step 4, when constructing the rapid flow trough and the rapid flow trough, first dig out the soil where the rapid flow trough is to be constructed, then backfill with the stirred modified soil, press the forming mold of the rapid flow trough on the loose modified soil, or use lightweight prefabricated components to splice to form the rapid flow trough; Then compact the modified soil on both sides of the rapid trough. If a forming mold is used to form the rapid trough, remove the forming mold after compacting the modified soil, and apply mortar to the rapid trough and its vicinity to complete the rapid trough.

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