A frame-type roadbed retaining structure

Abstract

This invention relates to a frame-type roadbed retaining structure, belonging to the fields of geotechnical engineering and structural engineering. It includes a frame structure comprising single rows of anti-slide piles on both sides of the road and longitudinal frame beams connected to the anti-slide piles along the road's extension direction, as well as transverse frame beams connected to the anti-slide piles along the road's width direction. The transverse frame beams include a top transverse frame beam located at the top of the road and a bottom transverse frame beam located below the road surface. Retaining slabs and floor slabs are respectively provided on both sides and the top of the frame structure. A rockfall impact buffer layer is provided on the floor slab at the top of the frame structure. This invention can be used for semi-cut roadbed slopes and fully cut roadbed slopes, primarily addressing the impact of large lateral earth pressure, landslide thrust, and rockfall impact loads on the road.

Description

Technical Field

[0001] This invention belongs to the field of geotechnical engineering and structural engineering technology, and relates to a frame-type roadbed retaining structure, which can be used for retaining slopes of excavated roadbeds; it can also be used as a tunnel structure for roads on mountain slopes. Background Technology

[0002] Many mountainous towns exist in western my country. Due to land constraints, many buildings, roads, and public facilities in these cities need to be built on mountain slopes.

[0003] For road excavation subgrades set on mountains, when there are deep, unstable soil layers or other situations that generate large sliding forces and earth pressures, traditional retaining structures are difficult to meet the needs of slope protection.

[0004] Traditional retaining structures generally employ two forms: double-row piles and anchored pile-slab retaining walls. Furthermore, due to the large loads, anti-slide piles typically require a square cross-section to meet the load-bearing requirements.

[0005] The existing technology has the following problems:

[0006] 1. Rectangular cross-section anti-slide piles are difficult to drill in deep soil layers in mountainous areas, posing significant construction safety risks.

[0007] 2. Traditional double-row pile structures are set on one side of the road, extending far beyond the road boundary, and occupy a large area.

[0008] 3. For anchored pile structures, it is difficult to drill holes for anchor cables in deep soil layers, and for slopes that undergo certain deformation in the later stages, it is easy to cause many problems with the anchor cables.

[0009] 4. When there is a possibility of rockfall on the mountainside, ordinary roadbed retaining structures do not have the function of preventing rockfall.

[0010] 5. Due to incomplete research and standards, it is difficult for ordinary roadbed retaining walls to fully utilize the seismic performance of the structure.

[0011] 6. After the road cut was excavated, the green space on the hillside was artificially divided, which destroyed the original function of the urban mountain greening. Summary of the Invention

[0012] In view of this, the purpose of this application is to provide a frame-type roadbed retaining structure for use in semi-cut roadbed slopes and fully cut roadbed slopes.

[0013] To achieve the above objectives, the present invention provides the following technical solution:

[0014] A frame-type roadbed retaining structure includes a frame structure, which includes a single row of anti-skid piles set on both sides of the road and longitudinal frame beams set along the road extension direction and connected to the anti-skid piles, as well as transverse frame beams set along the road width direction and connected to the anti-skid piles; the transverse frame beams include a top transverse frame beam located at the top of the road and a bottom transverse frame beam located below the road surface; retaining slabs and floor slabs are respectively provided on both sides and the top of the frame structure.

[0015] Optionally, a rockfall impact buffer layer is provided on the floor slab at the top of the frame structure.

[0016] Optionally, the top of the anti-slide pile on the slope side is lower than the top of the anti-slide pile in the adjacent row, and the height difference is not less than the impact buffer layer for preventing falling rocks.

[0017] Optionally, the frame structure is multi-layered and multi-segmented, with the top layer on the slope side being higher than the top layer of the adjacent segment.

[0018] Optionally, a rockfall impact buffer layer is provided at the top of the top layer on the slope side.

[0019] Optionally, the top layer of the frame structure may include a green landscape leisure area and / or a public building functional area.

[0020] Optionally, the top of the frame structure is higher than the mountain slope.

[0021] Optionally, the anti-slide pile has a circular cross-section.

[0022] Optionally, the rockfall protection buffer layer is a mixture of rubber fragments and lightweight sand.

[0023] The beneficial effects of this invention are as follows:

[0024] 1. The frame structure of the present invention has high lateral stiffness, and the anti-slide piles can be made with circular cross sections, which reduces the construction difficulty and risk compared with the rectangular cross sections of conventional roadbed anti-slide piles.

[0025] 2. Compared to traditional double-row pile structures, which extend significantly beyond the road boundary; and compared to traditional anchored pile structures, whose anchor cables occupy underground space outside the boundary. The frame structure of this invention, however, can be located within the entire road boundary, without occupying land on the outer side.

[0026] 3. Compared with traditional roadbed anchor pile structures, the prestressed anchor cables of anchor pile structures require drilling in landslide soil, which is difficult to construct. Furthermore, the anchor cables suffer from stress loss and other durability issues during long-term use, increasing management complexity. This invention, however, achieves the required stiffness without using anchor cables.

[0027] 4. This invention effectively blocks falling rocks from the hillside by setting an anti-falling rock impact buffer layer at the top of the frame, and has reliable anti-falling rock performance.

[0028] 5. The frame structure of the present invention can withstand greater deformation and can be designed for seismic resistance in accordance with the methods of building frame structures, which is conducive to maximizing the potential of the structure.

[0029] 6. The frame structure of this invention, in the form of a mountain-like building, connects the upper and lower green areas of the mountain, integrating the building into the mountain's greenery. Simultaneously, the added floors can be given the functions of a public building, thereby increasing the project's value.

[0030] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0031] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0032] Figure 1 This invention is a single-frame, single-layer structure.

[0033] Figure 2 This invention features a multi-frame, multi-layered structure.

[0034] Figure 3 This is a planar structural diagram of the present invention;

[0035] Figure 4 This is an elevation view of the structure of the present invention;

[0036] Figure 5 This is a simplified diagram of the structural forces of the present invention;

[0037] Figure 6 This is a cross-sectional view of the invention.

[0038] Attached reference numerals: 1. Mountain slope; 2. Anti-slide pile; 3. Longitudinal frame beam; 4. Retaining plate; 5. Transverse frame beam; 6. Road and building clearance; 7. Floor slab; 8. Parking area; 9. Green landscape and leisure area; 10. Public building area; 11. Soil-rock boundary line; 12. Intact bedrock line; 13. Sliding surface; 14. Ground spring; 15. Landslide thrust or earth pressure; 16. Landslide body; 17. Passive earth pressure; 18. Rockfall impact force; 19. Rockfall impact buffer layer; 20. Virtual contact surface; 21. Impact contact unit. Detailed Implementation

[0039] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0040] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0041] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0042] See Figures 1-6 A frame-type roadbed retaining structure includes a frame structure, which includes a single row of anti-skid piles 2 set on both sides of the road and a longitudinal frame beam 3 set along the road extension direction and connected to the anti-skid piles 2, and a transverse frame beam 5 set along the road width direction and connected to the anti-skid piles 2; the transverse frame beam 5 includes a top transverse frame beam located at the top of the road and a bottom transverse frame beam located below the road surface; retaining plates 4 and floor slabs 7 are respectively provided on both sides and the top of the frame structure.

[0043] In order to prevent falling rocks from the hillside, the present invention has a rockfall prevention structure, that is, a rockfall impact buffer layer is provided on the floor slab at the top of the frame structure. The rockfall impact buffer layer is a mixture of rubber fragments and lightweight sand.

[0044] Preferably, the top of the anti-slide pile 2 located on the slope side is lower than the top of the anti-slide pile 2 in the adjacent row, and the height difference is not less than the impact buffer layer for preventing falling rocks.

[0045] To achieve added value for the project, the frame structure of this invention is multi-layered and multi-segmented, with the top layer on the slope facing higher than the top layer of the adjacent segment. The top layer on the slope facing is covered with a buffer layer, and the remaining top layers can be used for green landscape leisure area 9 and / or public building functional area 10.

[0046] Preferably, the anti-slide pile 2 has a circular cross-section and is embedded 9m to 10m below the intact bedrock line 12.

[0047] In order not to damage the hillside landscape, the top of the frame structure of the present invention is slightly higher than the slope 1 of the mountain; when the frame structure is multi-layered and multi-framed, the top layer is set in a stepped manner along the slope to connect the upper and lower green areas of the mountain and integrate the building into the greening of the mountain.

[0048] This invention employs two or more rows of circular cross-section anti-slide piles 2, longitudinal frame beams 3 between the piles, and transverse frame beams 5 to form a spatial retaining structure. A retaining plate 4 between the piles is installed on the soil-facing side to retain soil. The road construction clearance 6 is placed between the circular cross-section anti-slide piles 2, meaning the circular cross-section anti-slide piles 2 are located on both sides of the road. Since there is no soil within the road construction clearance 6, the piles cannot transfer force through the soil within this range; force can only be transferred through the transverse frame beams 5. In practical applications, two or more rows of circular cross-section anti-slide piles 2 can be used depending on the road width distribution. A single-layer or multi-layer structure can be adopted according to the terrain, and the piles can be staggered along the mountain slope. Floor slabs 7 are installed between the added longitudinal frame beams 3 and transverse frame beams 5 to form floor spaces, which can be used as parking areas 8, green landscape leisure areas 9, public building areas 10, etc. Furthermore, similar to tunnel sheds, it has the function of preventing rockfalls. When using a multi-layer arrangement, the same rockfall impact buffer layer 19 is used, providing reliable fall protection performance. The rockfall impact force 18 of this invention is achieved by setting a rockfall impact buffer layer 19 on the top of the structure. This structure serves as a shelter, a retaining wall, and also as a public building.

[0049] The single-frame, single-layer design of this invention is suitable for roads without a central median and with narrow widths; the multi-frame, multi-layer design is suitable for roads with a central median and wider widths. The specific structural dimensions shown in the diagram are determined by calculation. Each frame can be freely combined as needed, facilitating the application of prefabricated building technology. Specific dimensions, models, and the number of frames are not specified here. The buffer layer at the top of the frame uses a mixture of rubber fragments and lightweight sand, with its thickness adjusted as needed based on calculations of the impact force of falling rocks.

[0050] Traditional retaining wall structures generally only consider the seismic performance of the structure in an elastic state, and cannot consider the performance under rare earthquakes. However, the frame structure of this invention can be designed for seismic resistance using methods similar to those for building frame structures. By employing response spectrum analysis and time history analysis methods from building seismic design codes, the seismic performance of the frame structure under rare earthquakes in a plastic state can be calculated. Combined with commonly used seismic-resistant devices in building structures, the seismic potential of the structure can be maximized.

[0051] This invention can be used for both semi-cut and fully cut roadbed slopes, and can withstand significant lateral earth pressure, landslide thrust, and impact loads from falling rocks. As a retaining wall structure, it not only increases structural reliability and durability, reduces construction risks, and improves seismic performance, but also incorporates certain architectural functions. The spatial integral frame form of this invention can be used for sheds, retaining walls, and public buildings.

[0052] Example

[0053] A frame-type roadbed retaining structure, which is a multi-frame, multi-layer frame structure. For example... Figure 6 As shown: The road construction clearance 6 is located in the middle of the mountain slope 1. The surface fill of the slope was formed by urban construction, with a thickness of 20-30m. Currently, it is a green area of ​​a mountain park, with underlying bedrock. After the road cut is excavated, the upper slope of the road will slide. The landslide force is converted to the anti-slide piles, which are distributed in a rectangular shape. Each pile bears a landslide load of 400KN / m. According to the road width layout, four rows of circular cross-section anti-slide piles 2 are used for support. The anti-slide piles 2 need to be embedded below the soil-rock boundary line 11, preferably 9m-10m below the intact bedrock line 12. The anti-slide piles are located on both sides of the road construction clearance 6. Transverse frame beams 5 are set at the top and below the road surface. Longitudinal frame beams 3 are set at the corresponding anti-slide pile positions. The longitudinal frame beams 3 are fixedly connected to the adjacent transverse frame beams 5. The top is arranged in stages according to the mountain slope, forming a structure as shown in the figure. Figure 6 The retaining structure is shown. Due to its high lateral stiffness, the anti-slide piles can be made with a circular cross-section. In addition to the traffic space of the road, the created public space can be used as a parking area 8, a green landscape leisure area 9, a public building area 10, etc. The top of the structure is greened and integrated with the mountain park, making this structure a part of the mountain park.

[0054] Mountain slope 1

[0055] Structural stress analysis, such as Figure 5As shown: The landslide thrust or earth pressure 15 acts on the circular cross-section anti-slide pile 2 on the adjacent side of the soil. The length of the pile above the road surface is the cantilever length of the pile, and the length of the pile below the road surface and below the sliding surface 13 is the embedment length of the pile. According to the geological conditions, the horizontal foundation resistance coefficient is calculated by the "m" method or the "k" method. Under the spatial coordination effect, the two ends of the frame beam can be approximately considered as fixed supports with a certain bending stiffness. The calculation is based on the deformation coordination principle, considering the static equilibrium method of the retaining structure, and the stiffness matrix is ​​established according to the finite element direct stiffness method for solution: {F}={k}{m}, where: {F} is the structural node load vector; {m} is the structural node displacement vector; {K} is the overall structural stiffness matrix. The finite element model is established as follows: the longitudinal frame beam 3, the transverse frame beam 5 and the circular cross-section anti-slide pile 2 adopt ordinary beam elements. When establishing the spatial model, the retaining plate 4 is represented by plate elements; when establishing the planar model, the retaining plate 4 is not considered. Boundary conditions: the embedded section of the anti-slide pile is set with ground spring elements 14 based on the stiffness calculation of the elastic resistance of soil and rock. The ground spring elements 14 include several ground springs connected to the anti-slide piles. The roadway beam (i.e., the bottom transverse frame beam) is calculated with stiffness calculated using the "Winkler" foundation beam method, and ground spring boundaries are set. The landslide thrust or earth pressure 15 acts as a load on the corresponding beam element. The circular cross-section anti-slide pile 2 located in the downslope direction of the frame needs to consider the passive earth pressure 17. The top rockfall impact buffer layer 19 is simulated by establishing impact contact elements 21. A virtual contact surface 20 is set at the top of the element, and the rockfall impact force 18 is applied.

[0056] Calculations of the slope displacement diagram during the final construction stage showed a maximum displacement of 40mm, indicating relatively small deformation. Based on the strength reduction method, the safety factor of the slope after support is 1.625. The plastic zone above the support structure is not continuous, and its safety factor is greater than 1.35, meeting the safety requirements.

[0057] In summary, in this example, the present invention effectively solves the problems of slope support in excavated roadbeds under heavy loads and rockfall, exhibiting strong construction safety, structural stability, and structural durability. Simultaneously, it integrates architectural functions into municipal roads. Its main applicable scope is as follows:

[0058] 1) Roads or tunnel openings on mountain slopes subject to large loads or with slope stability risks.

[0059] 2) Road excavation subgrade that is subject to greater stress but requires less land occupation by retaining structures outside the road red line.

[0060] 3) Road slopes that require enhanced lateral stiffness of anti-slide piles but are not suitable for use with anchor cables.

[0061] 4) There is a possibility of rockfall on the mountain, so there is a need for fall protection.

[0062] 5) Road projects that have the conditions or need to expand and develop urban public space and underground space.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A frame-type roadbed retaining structure, characterized in that: The structure includes a frame structure comprising single rows of anti-slide piles on both sides of the road and longitudinal frame beams connected to the anti-slide piles along the road's extension direction, as well as transverse frame beams connected to the anti-slide piles along the road's width direction. The transverse frame beams include a top transverse frame beam located at the top of the road and a bottom transverse frame beam located below the road surface. Retaining slabs and floor slabs are respectively provided on both sides and the top of the frame structure. The frame structure is multi-layered and multi-slab, with the top layer on the slope facing higher than the top layer of the adjacent slab. The top of the frame structure is higher than the mountain slope, and the top layer is set in a stepped manner along the mountain slope to connect the upper and lower green areas of the mountain and integrate the building into the mountain greening, avoiding damage to the mountain slope landscape. A rockfall impact buffer layer is provided on the floor slab at the top of the frame structure. The top of the anti-slide piles on the slope facing is lower than the top of the adjacent row of anti-slide piles, and the height difference is not less than that of the rockfall impact buffer layer.

2. The frame-type roadbed retaining structure according to claim 1, characterized in that: The top layer on the slope is equipped with a rockfall impact buffer layer.

3. The frame-type roadbed retaining structure according to claim 1, characterized in that: The top floor of the frame structure is equipped with a green landscape leisure area and / or a public building functional area.

4. A frame-type roadbed retaining structure according to claim 1, characterized in that: The anti-slide pile has a circular cross-section.

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