A roadbed protection structure

Abstract

The present application discloses a roadbed protection structure, wherein the roadbed is located between an existing railway and an existing building, and the protection structure comprises a plate beam, which is laid on the roadbed and optimizes the load of the roadbed; and micro piles, which are arranged below the plate beam and at least partially located in the plate beam, and the micro piles provide support for the plate beam. The roadbed protection structure of the present application has the advantages of strong bearing capacity and high stability.

Description

Technical Field

[0001] The present application relates to the field of geotechnical engineering, and in particular to a roadbed protective structure. Background Art

[0002] The construction of roadbeds in special rock and soil areas such as soft soil, expansive (rock) soil, loess, saline soil, and restricted areas near existing buildings (structures) has always been a key and difficult point in engineering construction. The problem lies in how to safely deal with special rock and soil foundations while ensuring the safety and stability of existing buildings (structures).

[0003] At present, for roadbed construction projects in special rock-soil areas and restricted areas near existing buildings (structures), the measures commonly adopted are to treat the special rock-soil foundation and the restricted areas near existing buildings (structures) separately, such as using pile-plate structure and retaining wall or anti-slide pile protection structure; pipe pile, pile raft and retaining wall or anti-slide pile protection structure; and CFG pile, pile raft and retaining wall or anti-slide pile protection structure. In addition, due to the proximity to existing buildings (structures), in order to reduce the impact, stronger foundation treatment measures and protection measures are adopted. Although the pile-plate structure and pile raft construction have better treatment effects, the cast-in-place pile foundation uses impact drilling, and the pipe pile and CFG pile construction equipment requires a higher space and causes greater disturbance to the stratum. Especially when the roadbed passes under an existing bridge, the site is limited, and special rock-soil areas are prone to instability and damage caused by insufficient foundation bearing capacity. The roadbed protection structure in the existing technology has problems with poor bearing capacity and stability. Summary of the Invention

[0004] In view of this, an embodiment of the present application hopes to provide a roadbed protection structure to solve the problems of poor bearing capacity and stability of the roadbed protection structure.

[0005] To achieve the above-mentioned objectives, an embodiment of the present application provides a roadbed protection structure, wherein the roadbed is located between an existing railway and an existing building, and the protection structure comprises:

[0006] A plate beam, laid on the roadbed, optimizes the load on the roadbed; and

[0007] Micro piles are arranged below the plate beam and connected to the plate beam, and the micro piles provide support for the plate beam.

[0008] Furthermore, the micro pile comprises:

[0009] a first pile body, disposed below the plate beam and connected to the plate beam; and

[0010] The reinforcement body is arranged on the first pile body to reinforce the first pile body.

[0011] Furthermore, the reinforcement body is a protective sleeve, the protective sleeve is formed with a plurality of holes, and the first pile body is cast in the protective sleeve.

[0012] Furthermore, the protective sleeve is provided with a circle of holes at intervals of 20 cm to 50 cm in the longitudinal direction, each circle of holes has 3 to 4 holes, and the diameter of the holes is 1 cm to 2 cm.

[0013] Furthermore, the micro pile further includes a reinforcing steel bar, one end of which is arranged on the upper part of the first pile body, and the other end of which is connected and fixed to the plate beam.

[0014] Furthermore, the reinforcement body is a steel frame, which is arranged inside the first pile body, with one end arranged at the bottom of the first pile body and the other end protruding from the top of the first pile body and connected and fixed to the plate beam.

[0015] Furthermore, the steel frame includes 3 to 4 longitudinal steel bars, one end of which is arranged at the bottom of the first pile body, and the other end protrudes from the top of the first pile body and is connected and fixed to the plate beam. The diameter of the longitudinal steel bar is 8 mm to 16 mm.

[0016] Furthermore, the steel frame also includes stirrups to bind and fix the longitudinal steel bars, and the diameter of the stirrups is 6mm to 10mm.

[0017] Furthermore, the longitudinal steel bars are evenly arranged in a triangle or quadrilateral in the first pile body.

[0018] Furthermore, the length of the first pile body is 4m to 10m, the diameter of the first pile body is 0.15m to 0.3m, and the distance between the first pile bodies is 0.5m to 1.2m.

[0019] Furthermore, the first piles are evenly arranged in a triangle or square shape along the bottom of the plate beam.

[0020] Furthermore, the plate beam includes:

[0021] a plate body, laid on the roadbed; and

[0022] The stress-bearing steel bars are arranged in the plate body and connected with the micro piles.

[0023] Furthermore, each section of the plate has a length of 4m to 6m, a thickness of 0.4m to 0.6m, and a width of 4m to 6m.

[0024] Furthermore, structural seams are formed between adjacent plates.

[0025] Furthermore, the top surface of one side of the plate body close to the existing building is lower than the top surface of the other side.

[0026] Furthermore, the plate beam also includes a supporting plate, which is protrudingly arranged on a side of the plate body close to the existing building.

[0027] Furthermore, the width of the support plate is 0.3m to 0.8m, and the height of the support plate is 0.6m to 2m.

[0028] Furthermore, the protective structure also includes a protective part, which is arranged between the roadbed and the existing railway, and between the supporting plate with a height greater than 1m and the existing building.

[0029] Furthermore, the protection part includes:

[0030] a second pile body, one end of which is disposed in the roadbed and the other end of which is exposed outside the roadbed; and

[0031] A connecting beam is connected between the upper portions of at least two of the second pile bodies.

[0032] Furthermore, the spacing between the second pile bodies is 0.3m to 0.5m, and the length of the second pile body is 2 to 2.5 times the excavation depth of the foundation pit of the slab beam.

[0033] Furthermore, the protective structure also includes a line drainage portion, which is arranged on the outside of the existing building.

[0034] Furthermore, the protective structure also includes an underground seepage ditch, which is arranged at the intersection of the lower part of the plate beam and the existing railway.

[0035] Furthermore, the protective structure also includes a ballast seepage ditch, which is arranged on the top surface of the slab beam adjacent to the supporting plate.

[0036] Furthermore, the protective structure also includes a surface observation pile, which is arranged on the ground on the side of the plate beam close to the existing building.

[0037] Furthermore, the protective structure also includes an existing railway observation pile, which is arranged on the shoulder of the existing railway on the side of the plate beam close to the existing railway.

[0038] Furthermore, the protective structure also includes an existing building observation point, which is set on the existing building.

[0039] An embodiment of the present application provides a roadbed protection structure, in which the roadbed is located between an existing railway and an existing building, and the protection structure includes a slab beam and micro piles. The slab beam is laid on the roadbed to protect the roadbed, and the micro piles are arranged below the slab beam to provide support for the slab beam. The micro piles have little disturbance to the special rock and soil roadbed, and can effectively solve the problem of insufficient bearing capacity of the special rock and soil roadbed. The micro piles are constructed using a 100-type motor drill, a Luoyang shovel or a down-the-hole drill. Compared with the large-scale mechanical equipment required for the construction of conventional pipe piles, cast-in-place piles, etc., the micro piles have the advantages of convenient construction and simple site requirements, and the construction with small equipment can speed up the construction progress and effectively save construction time. The slab beams and micro piles reinforce the roadbed, improving the stability and bearing capacity of the protection structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic top view of the application of the protective structure of the roadbed in the embodiment of the present application;

[0041] Figure 2 for Figure 1 Cross-sectional view in the AA direction;

[0042] Figure 3 A schematic top view of a roadbed protection structure in an embodiment of the present application;

[0043] Figure 4 This is a schematic diagram of the structure of the plate beam in the embodiment of this application;

[0044] Figure 5 This is a schematic diagram of the connection structure between the micro pile and the plate beam in the embodiment of the present application, wherein the reinforcement body is a protective sleeve;

[0045] Figure 6 This is a schematic diagram of the connection structure between the micro pile and the plate beam in the embodiment of the present application, wherein the reinforcement is a steel bar frame;

[0046] Figure 7 This is a schematic structural diagram of the protection portion in an embodiment of the present application;

[0047] Figure 8 A schematic diagram of the structure of an underground infiltration ditch in an embodiment of the present application; and

[0048] Figure 9 for Figure 5 The cross-sectional view in the middle BB direction shows three reinforcing steel bars, which are set according to the corner points of the triangle.

[0049] Description of Reference Numerals

[0050] 1. Protective structure; 2. Plate beam; 3. Micro pile; 4. Protective part; 7. Existing building; 8. Existing railway; 9. New railway; 10. Ballast; 11. Shoulder; 12. Ground line; 20. Plate; 21. Stressed steel bar; 22. Retaining plate; 23. Structural joint; 30. First pile; 31. Protective casing; 32. Reinforced steel bar; 33. Steel bar frame; 34. Stirrups; 35. Longitudinal steel bar; 40. Second pile; 41. Connecting beam; 50. Line drainage part; 51. Underground seepage ditch; 52. Ballast seepage ditch; 60. Surface observation pile; 61. Existing railway observation pile; 62. Existing building observation point; 510. Sand and gravel; 511. Needle-punched non-woven geotextile; 513. Filamentous internal support seepage drainage mesh pipe; 514. Medium-coarse sand. DETAILED DESCRIPTION

[0051] It should be noted that, unless there is a conflict, the embodiments and technical features in the embodiments of this application can be combined with each other, and the detailed description in the specific implementation method should be understood as an explanation of the purpose of this application and should not be regarded as an improper restriction on this application.

[0052] The orientation terms in the description of this application are only used to facilitate the description of this application and simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting this application.

[0053] The present application embodiment provides a roadbed protection structure, see Figures 1 to 3 As shown, a protective structure 1 for a roadbed in special soils, such as soft soil, expansive soil, loess, or saline soil, is shown. The roadbed is located between an existing railway 8 and an existing building 7. The protective structure 1 includes a slab beam 2 and micropiles 3. The slab beam 2 is laid on the roadbed to protect it. The micropiles 3 are arranged below the slab beam 2 and are at least partially located within the slab beam 2 to provide support for the slab beam 2.

[0054] In one embodiment, see Figures 1 to 3As shown, the roadbed of the newly built railway 9 is located between the existing railway 8 and the existing building 7. The roadbed protection structure 1 includes a slab beam 2 and micropiles 3. The slab beam 2 is laid on the roadbed and optimizes the load on the roadbed. The micropiles 3 are set below the slab beam 2 to provide support for the slab beam 2. The micropiles 3 cause less disturbance to the special rock and soil roadbed and can effectively solve the problem of insufficient bearing capacity of the special rock and soil roadbed. The micropiles 3 are constructed using a 100-type motor drill, Luoyang shovel or down-the-hole drill. Compared with the large mechanical equipment required for the construction of conventional pipe piles, cast-in-place piles, etc., they have the advantages of convenient construction and simple site requirements. In addition, the use of small equipment can speed up the construction progress and effectively save construction time. The slab beam 2 and micropiles 3 reinforce the roadbed. The slab beam 2 is set at the bottom of the ballast 10 to bear the loads of the track, ballast 10 and trains, and transfer the load to the roadbed and micropiles 3, thereby protecting the roadbed. The protective structure 1 of the embodiment of the present application has the advantages of strong bearing capacity, high stability and enhanced protection of restricted roadbed.

[0055] In one embodiment, see Figures 1 to 6 As shown, the micropile 3 includes a first pile body 30 and a reinforcement body. The first pile body 30 is disposed below and connected to the slab girder 2, and is at least partially located within the slab girder 2. The reinforcement body is disposed on the first pile body 30 to reinforce the first pile body 30. The micropile 3 is connected to the slab girder 2 via the first pile body 30 and the reinforcement body, improving the stability and bearing capacity of the slab girder 2. The reinforcement body is disposed on the first pile body 30 to reinforce the first pile body 30, thereby increasing the bearing capacity of the micropile 3 and, consequently, the stability and bearing capacity of the roadbed.

[0056] In one embodiment, the first pile body 30 is a cylinder and is arranged below the slab beam 2. Of course, the first pile body 30 can also be other shapes such as a prism. The first pile body 30 should be at least partially located in the bottom of the slab beam 2 to improve the overall strength and stability of the protective structure 1. Before the construction of the micro pile 3, an on-site process test should be carried out to obtain the corresponding pile parameters and construction process and technical parameters. Specifically, when constructing the first pile body 30, a 100-type motor drill, a Luoyang shovel or a down-the-hole drill is used to form a hole, and the soil layer should be dry-drilled. Compared with the large-scale mechanical equipment required for the construction of conventional pipe piles, cast-in-place piles, etc., the use of micro piles 3 has the advantages of convenient construction and simple site requirements, and the construction with small equipment can speed up the construction progress and effectively save construction time. The use of micro piles 3 causes little disturbance to the roadbed during construction, can effectively deal with the problem of insufficient bearing capacity of special rock and soil foundations, and can effectively prevent the large disturbance to the roadbed from affecting the stability of the roadbed.

[0057] Preferably, the first pile 30 is vertically disposed below the plate beam 2. This vertical placement of the first pile 30 below the plate beam 2 provides stronger support for the plate beam 2, allows it to withstand greater loads, and improves the overall structural stability of the protective structure 1. Of course, the first pile 30 can also be disposed below the plate beam 2 at a certain angle.

[0058] In one embodiment, see Figure 4 As shown, the reinforcement is a protective sleeve 31 having a plurality of holes formed therein, and the first pile body 30 is cast and formed within the protective sleeve 31. When the reinforcement is the protective sleeve 31, during the construction of the micropile 3, a hole is first formed using a 100-type power drill, a Luoyang shovel, or a down-the-hole drill. After the drilling is completed, the protective sleeve 31 is placed into the hole, and then one or both of fine stone concrete and cement mortar are poured into the protective sleeve 31 to form the micropile 3. When fine stone concrete is used, the concrete grade should be no less than C30, and the coarse aggregate particle size in the fine stone concrete should be less than 3 cm. When cement mortar is used, the cement mortar strength should be no less than M40, and the cement should be PO42.5 grade ordinary Portland cement. When the groundwater is corrosive, the grouting material should be anti-corrosion cement, and admixtures should be added if necessary. When the protective sleeve 31 is used, the hole shrinkage can be prevented after the drilling is completed, which is more conducive to grouting and can increase the strength of the micropile 3. A plurality of holes are formed on the protective sleeve 31 . During grouting, part of the grout will penetrate into the soil of the roadbed through the holes, ensuring that the protective sleeve 31 is in close contact with the soil of the roadbed, thereby increasing the anchoring force and bearing capacity of the micro pile 3 .

[0059] Specifically, the protective casing 31 is a steel casing. It possesses sufficient strength and durability, and is not easily damaged by reactions with water or oxygen in the roadbed soil. The steel casing is 2 mm to 5 mm smaller than the borehole diameter, has a wall thickness of 0.5 mm to 2 mm, and is the same length as the micropile 3. The steel pipe body is provided with circular holes with a diameter of approximately 10 to 20 mm, with three to four holes per cross-section, arranged in an alternating isosceles triangle or square pattern. When the roadbed is located in a soft rocky area, the micropile 3 is preferably reinforced with the protective casing 31.

[0060] Specifically, the protective sleeve 31 is provided with a circle of holes at intervals of 20 to 50 cm along the longitudinal direction, with each circle containing 3 to 4 holes, and the holes have a diameter of 1 to 2 cm. Too many holes will affect the strength of the protective sleeve 31, while too few holes will not ensure a close contact between the micropile 3 and the roadbed soil after the reinforcement is poured, thereby increasing the anchoring and bearing capacity of the micropile 3.

[0061] In one embodiment, see Figure 4 as well as Figure 9As shown, the micropile 3 also includes reinforcing bars 32, one end of which is disposed above the first pile body 30 and the other end is connected and fixed to the slab beam 2. Specifically, the reinforcing bars 32 are disposed at 1 / 3 of the length of the upper portion of the first pile body 30, and three to four bars are provided, arranged at the corner points of an equilateral triangle or square. The reinforcing bars 32 extend out of the first pile body 30 and are connected and fixed to the slab beam 2. The reinforcing bars 32 are HRB400 steel bars with a diameter of 8 mm to 16 mm.

[0062] In one embodiment, see Figure 4 as well as Figure 9 As shown, the micropile 3 also includes stirrups 34. Stirrups 34 are arranged in conjunction with the reinforcing bars 32 to form a closed, equilateral triangular or square ring structure. Stirrups 34 are made of HRB400 steel bars with a diameter of 6 mm to 10 mm. Stirrups 34 ensure shear strength, connect the reinforcing bars 32, and secure the reinforcing bars 32.

[0063] In one embodiment, see Figure 5 As shown, the reinforcement is a steel bar frame 33, which is arranged inside the first pile body 30. One end of the steel bar frame 33 is arranged at the bottom of the first pile body 30, and the other end protrudes from the top of the first pile body 30 and is fixedly connected to the plate beam 2. When the reinforcement is the steel bar frame 33, during the construction of the micropile 3, a 100-type motor drill, a Luoyang shovel or a down-the-hole drill is first used to drill a hole. After the drilling is completed, the steel bar frame 33 is inserted into the hole. After the steel bar frame 33 is installed, one or both of fine stone concrete or cement mortar are poured into the hole to form the micropile 3. The steel bar frame 33 is provided throughout the length of the first pile body 30 to increase the strength and supporting force of the first pile body 30. When the roadbed is a special rock or soil such as expansive (rock) soil, loess, or saline soil, the micropile 3 is preferably a micropile 3 with the steel bar frame 33 as the reinforcement.

[0064] In one embodiment, the reinforcement is a pre-embedded anchor bolt, which is disposed within the first pile body 30. One end of the pre-embedded anchor bolt is disposed at the bottom of the first pile body 30, and the other end is disposed at the top of the first pile body 30 and connected to the slab beam 2. When the reinforcement is a pre-embedded anchor bolt, during the construction of the micropile 3, a hole is first drilled using a 100-type power drill, a Luoyang shovel, or a down-the-hole drill. After drilling is completed, the steel frame 33 is inserted into the hole. After the pre-embedded anchor bolt is installed, one or both of fine stone concrete and cement mortar are poured into the hole to form the micropile 3. The pre-embedded anchor bolt is longer than the first pile body 30. The extended portion is connected to the slab beam 2 by bolts or integrally formed, thereby increasing the strength and support capacity of the first pile body 30.

[0065] Specifically, see Figure 5As shown, the reinforcement frame 33 includes three to four longitudinal steel bars 35. One end of the longitudinal steel bars 35 is disposed at the bottom of the first pile body 30, and the other end protrudes from the top of the first pile body 30 and is fixed to the plate beam 2. The diameter of the longitudinal steel bars 35 is 8 mm to 16 mm. A sufficient number and size of longitudinal steel bars 35 can ensure the strength of the first pile body 30. The reinforcement frame 33 is composed of three to four longitudinal steel bars 35 with a diameter of 8 mm to 16 mm, which ensures sufficient strength without wasting material and increasing costs.

[0066] In one embodiment, see Figure 5 As shown, the reinforcement frame 33 also includes stirrups 34, which bind and secure the longitudinal reinforcements 35. The stirrups 34 have a diameter of 6 mm to 10 mm. The stirrups 34 ensure shear strength of the oblique section, connect the longitudinal reinforcements 35 in the reinforcement frame 33, and further secure the longitudinal reinforcements 35 in the reinforcement frame 33.

[0067] Specifically, the longitudinal steel bars 35 are evenly arranged in a triangular or quadrilateral shape in the first pile body 30. When the steel bar frame 33 includes three longitudinal steel bars 35, the longitudinal steel bars 35 are evenly arranged in a triangular shape at the three corner points of the first pile body 30; when the steel bar frame 33 includes four longitudinal steel bars 35, the longitudinal steel bars 35 are evenly arranged in a quadrilateral shape at the four corner points of the first pile body 30.

[0068] Specifically, the length of the first pile 30 is 4 to 10 meters, the diameter of the first pile 30 is 0.15 to 0.3 meters, and the spacing between the first piles 30 is 0.5 to 1.2 meters. The micropiles 3 are used to provide anchoring force for the slab girder 2 and bear the load. Therefore, failure of the micropiles 3 will lead to failure of the entire protective structure 1, which in turn may cause roadbed instability. Therefore, the strength of the micropiles 3 is very important. Selecting an appropriate length for the first pile body 30 can ensure the anchoring force of the first pile body 30. If the first pile body 30 is too short, the anchoring force will be weakened. An appropriate diameter of the first pile body 30 can ensure the strength of the first pile body 30. If the diameter of the first pile body 30 is too small, the strength of the first pile body 30 will be too small, and it will be easily damaged, causing the protective structure 1 to become unstable. If the diameter of the first pile body 30 is too large, it will easily cause excessive disturbance to the roadbed stratum, affecting the stability of the protective structure 1. Maintaining an appropriate spacing between the first pile bodies 30 can prevent the first pile bodies 30 from being too densely arranged, causing excessive disturbance to the roadbed stratum, thereby affecting the stability of the protective structure 1. However, if the first pile bodies 30 are too sparsely arranged, it will also affect the overall strength of the micro pile 3, thereby affecting the reliability and stability of the protective structure 1.

[0069] Specifically, the first piles 30 are evenly arranged in a triangular or square pattern along the bottom of the plate girder 2. The first piles 30 are arranged in a single row, double row, or multiple rows. Multiple rows can also form a plum blossom pattern. Preferably, the first piles 30 are evenly arranged in a triangular or square pattern along the bottom of the plate girder 2. This even triangular or square pattern improves the load-bearing performance of the plate girder 2.

[0070] In one embodiment, see Figures 4-6 As shown, the slab beam 2 includes a slab body 20 and stress-bearing reinforcement bars 21. The slab body 20 is laid on the roadbed, and the stress-bearing reinforcement bars 21 are disposed within the slab body 20 and connected to the micropiles 3. The connection of the stress-bearing reinforcement strips to the micropiles 3 enhances the anchoring force between the micropiles 3 and the slab beam 2, thereby improving the structural stability of the protective structure 1. The micropiles 3 are connected to the stress-bearing strips of the slab beam 2, which rationally and fully distributes the stress in the protective structure 1 and optimizes the stresses on the protective structure 1. This has the advantages of increasing the bearing capacity of the roadbed soil, rationalizing stress characteristics, achieving high stability, a simple structure, and strong integrity.

[0071] Specifically, each section of the plate 20 has a length of 4m to 6m, a thickness of 0.4m to 0.6m, and a width of 4m to 6m, thereby ensuring the strength of the protective structure 1 and facilitating construction.

[0072] In one embodiment, see Figure 1 as well as Figure 3 As shown, structural joints 23 are formed between the plates 20. Structural joints 23 are a general term for expansion joints, settlement joints, and seismic joints installed between adjacent buildings or building sections to mitigate thermal expansion and contraction, foundation settlement, and vibration and impact. Structural joints 23 are settlement joints installed at appropriate locations between the plate beams 2 to mitigate longitudinal structural damage caused by thermal stress and uneven settlement.

[0073] In one embodiment, the width of the structural seam 23 is 1 cm to 2 cm, and the structural seam 23 is densely filled with asphalt hemp tendons, or densely filled with one or more materials such as acetone glue and polyurethane.

[0074] The width of the structural joint 23 is calculated and determined based on the actual application scenario, the geological conditions of the slope, and other factors. To prevent foreign objects from entering the structural joint 23 and causing damage to the structural joint 23, one or more of asphalt hemp, acetone glue, and polyurethane are filled into the structural joint 23.

[0075] Specifically, the slab 20 is a reinforced concrete slab, installed at the bottom of the ballast. It bears the loads of the track, ballast, and trains, and transfers these loads to the roadbed and micropiles 3. The slab 20 is constructed of reinforced concrete with a concrete grade no lower than C30 and HRB400 steel. Micropiles 3 are installed at the bottom of the reinforced concrete slab 20. The longitudinal steel bars 35 or reinforcing bars 32 of the micropiles 3 extend into the slab 20 and are welded or tied to the load-bearing steel bars 21 within the slab 20, ensuring a tight connection.

[0076] In one embodiment, the top surface of the slab 20 on the side closest to the existing building 7 is lower than the top surface on the other side. The top surface of the slab 20 is sloped to prevent water accumulation on top of the floor beam 2. A drainage slope of 3% to 5%, for example, 3%, 4%, or 5%, is provided toward the side adjacent to the existing building 7. Specifically, a drainage slope of 4% is provided toward the side adjacent to the existing building 7 to prevent water accumulation on top of the slab beam. The existing building 7 includes existing buildings 7 and existing structures.

[0077] In one embodiment, see Figures 1 to 4 As shown, the plate beam 2 also includes a retaining plate, which is protrudingly arranged on the side of the plate body 20 close to the existing building 7. The retaining plate is arranged on the side of the plate body 20 close to the existing building 7, which can effectively protect the stability of the existing building 7 and has a good overall protection effect.

[0078] Specifically, the width of the support plate is 0.3m to 0.8m, and the height of the support plate is 0.6m to 2m. The width of the support plate is 0.3m to 0.8m, for example, 0.3m, 0.4m, 0.5m, 0.6m, 0.7m, or 0.8m. This sufficient width ensures the strength of the support plate 22. The height of the support plate is 0.6m to 2m, for example, 0.6m, 0.8m, 1m, 1.6m, 1.8m, or 2m. This sufficient height ensures the supporting effect of the support plate 22. The bottom height of the support plate 22 is no less than 0.6m and the height of the ballast 10.

[0079] Preferably, the support plate 22 is integrally formed with the plate body 20. The integral formation of the support plate 22 and the plate body 20 can ensure the strength of the support plate 22. Compared with the case where the support plate 22 and the plate body 20 are not integrally formed, the integral formation of the support plate 22 and the plate body 20 has better support effect and structural stability.

[0080] In one embodiment, see Figure 2 as well as Figure 7As shown, the protective structure 1 also includes a protective portion 4, which is positioned between the roadbed and the existing railway 8, and between a retaining plate greater than 1m in height and the existing building 7. Positioning the protective portion 4 between the roadbed and the existing railway 8 ensures the safety and stability of the roadbed of the existing railway 8 during construction. Positioning the protective portion 4 between a retaining plate greater than 1m in height and the existing building 7 further ensures the safety and stability of the existing building 7 during construction, while also protecting the retaining plate 22 and ensuring the overall strength of the protective structure 1.

[0081] In one embodiment, see Figure 7 As shown, the protective part 4 includes a second pile body 40 and a connecting beam 41. One end of the second pile body 40 is set in the roadbed, and the other end is exposed on the roadbed; the connecting beam 41 is connected between the upper parts of at least two second pile bodies 40. The second pile body 40 can be an abandoned steel rail, a steel rail or a steel pipe. When an abandoned steel rail is used, it can not only ensure the strength of the protective part 4, but also recycle the abandoned steel rail, save resources and reduce costs. Of course, the second pile body 40 can also be a steel rail and a steel pipe, which can also ensure the strength of the protective part 4. The connecting beam 41 is connected between the upper parts of at least two second pile bodies 40, connecting the second pile bodies 40 in the protective part 4 so that they work together. In addition, it can also fix the second pile bodies 40 in the protective part 4. Specifically, the connecting beam 41 is a steel rail, which is welded together with the second pile body 40 to form a whole, thereby improving the stress-bearing performance of the protective part 4.

[0082] In one embodiment, the spacing between the second piles 40 is 0.3m to 0.5m, and the length of the second piles 40 is 2 to 2.5 times the excavation depth of the foundation pit for the slab beam 2. The spacing between the second piles 40 is 0.3m to 0.5m, for example, 0.3m, 0.4m, or 0.5m. This appropriate spacing can ensure the load-bearing performance of the protective part 4 without wasting resources or increasing construction time due to overcrowding. The foundation pit for the slab beam 2 is excavated from the ground line 12, and the length of the second piles 40 is 2 to 2.5 times the excavation depth of the foundation pit for the slab beam 2, ensuring sufficient length for the second piles 40 and improving the protective effect and load-bearing performance of the protective part 4.

[0083] In one embodiment, see Figure 1 as well as Figure 2 As shown, the protective structure 1 also includes a line drainage section 50, located outside the existing building 7. The drainage section should, based on topographical conditions, intercept surface water outside the roadbed to prevent it from intruding into the railway subgrade, while also draining surface water from both sides of the subgrade. Due to the influence of the adjacent existing building 7, the line drainage section 50 cannot be located at the edge of the railway line. Instead, it is located a safe distance away from the outside of the adjacent existing building 7. Specifically, the line drainage section 50 can take the form of a circular drainage pipe or a drainage ditch, with a drainage slope of no less than 2‰ along the direction of water flow.

[0084] In one embodiment, see Figure 2 as well as Figure 8 As shown, the protective structure 1 also includes an underground seepage ditch 51, which is arranged at the intersection of the lower part of the slab beam 2 and the existing railway 8. Specifically, the underground seepage ditch 51 has a width of 0.3m to 0.5m and a height of 0.3m to 0.6m. The upper part of the underground seepage ditch 51 is clean sand and gravel 510 wrapped in a needle-punched non-woven geotextile 511 with a height of 0.1m to 0.15m; the lower part of the underground seepage ditch 51 is a drainage ditch with a width of 0.2m to 0.35m. The clean sand and gravel 510 wrapped in the needle-punched non-woven geotextile 511 is made of clean sand and gravel with a maximum particle size of less than 6cm. The rock material should be hard rock and the fine soil content should be less than 3%. The drainage ditch has a wall thickness of 0.05m and is prefabricated with reinforced concrete. A high-strength filamentous internal support seepage drainage network pipe 513 with a diameter of 10cm is built into the drainage ditch. The remaining space in the drainage ditch is filled with clean medium-coarse sand 514. The drainage from the underground seepage ditch 51 is led to the line drainage part 50 at a suitable location.

[0085] In one embodiment, see Figure 1 as well as Figure 2 As shown, the protective structure 1 also includes a ballast seepage ditch 52, located on the top surface of the slab girder 2 adjacent to the support plate. Specifically, the ballast seepage ditch 52 can be made of steel pipe or a high-strength filamentary internal support drainage mesh pipe 513 with a diameter of 10cm to 15cm. When using steel pipe, the steel pipe wall must be provided with circular holes, with a circle of circular holes spaced 0.5m to 1m along the longitudinal direction of the steel pipe, with 3 to 4 circular holes per circle, and a diameter of 1cm to 2cm. This ensures that water accumulated on the top of the slab girder 2 can be smoothly discharged through the ballast seepage ditch 52.

[0086] In one embodiment, see Figure 2 As shown, the protective structure 1 also includes a surface observation pile 60, which is installed on the ground on the side of the slab beam 2 near the existing building 7. The surface observation pile 60 is placed on the ground on the side of the slab beam 2 near the existing building 7 to monitor the deformation of the existing building 7 during construction. Specifically, the surface observation pile 60 uses a steel drill with a diameter of no less than 16 cm and a length of 0.5 m. The top of the surface observation pile is equipped with a hemispherical measuring tip with a cross-marked line for deformation monitoring. The surface observation pile 60 is penetrated into the surface soil by hammering, and the exposed length is 3 cm to 5 cm.

[0087] In one embodiment, see Figure 2As shown, the protective structure 1 also includes an existing railway observation pile 61, which is installed on the shoulder 11 of the existing railway 8 on the side of the plate beam 2 close to the existing railway 8. The existing railway observation pile 61 is installed on the shoulder 11 of the existing railway 8 on the side of the plate beam 2 close to the existing railway 8 and is used to monitor the deformation of the roadbed of the existing railway 8 during construction. The existing railway observation pile 61 uses a steel drill with a diameter of not less than 16 cm and a length of 0.3 m. The top of the existing railway observation pile is equipped with a hemispherical measuring end with a cross-marked line for deformation monitoring. The existing railway observation pile 61 is penetrated into the surface soil by hammering, and the exposed length is 3 cm to 5 cm.

[0088] In one embodiment, see Figure 2 As shown, the protective structure 1 also includes an existing building observation point 62, installed on the existing building 7. This existing building observation point 62 is located adjacent to the existing building 7 and is used to monitor deformation of the adjacent existing building 7 during construction. The existing building observation point 62 utilizes a steel chisel with a diameter of 10 to 12 cm and a length of 0.1 to 0.15 m. It is equipped with a hemispherical measuring tip with a cross-marked marking for deformation monitoring. The existing building observation point 62 is drilled at a typical location on the existing building 7. After the hole is filled with cement mortar, the adjacent structure observation point is inserted into the hole and firmly bonded. The exposed length of the existing building observation point 62 is 1 to 1.5 cm.

[0089] In one embodiment, see Figure 2 As shown, protective structure 1 includes a monitoring system consisting of surface observation piles 60, existing railway observation piles 61, and existing building observation points 62. This system provides safety warnings during construction. An alert is issued when the deformation data monitored by surface observation piles 60 exceeds 1 mm / day, or the total deformation exceeds 3 cm. An alert is also issued when the deformation data monitored by existing building observation point 62 exceeds the allowable value specified in relevant standards and regulations. After the alert is issued, counter-pressure backfilling measures should be implemented, and construction can only resume after further investigation and strengthening measures are implemented. The monitoring system should be buried before construction, and initial readings should be taken twice, with an interval of at least one day between the two readings. The average value should be used as the initial reading. Monitoring should be conducted once a day during construction. The monitoring system should be properly protected during construction to prevent damage. The monitoring system is set up according to sections, with sections spaced 15 to 20 meters apart.

[0090] In one embodiment, see Figure 1 as well as Figure 2As shown, the protective structure 1 includes micro piles 3, plate beams 2, a drainage system, a protective part 4, and a monitoring system. Micro piles 3 and plate beams 2, as the main load-bearing structures, are mainly used to reinforce special rock foundations and bear the upper roadbed structure. At the same time, they bear the roadbed track structure load, train load, etc. At the same time, they ensure that the excavation during the construction of the restricted roadbed will not affect the safety and stability of the adjacent existing buildings 7 and the existing railway 8, thereby reducing the risks of construction and operation. The main function of the drainage system is to solve the horizontal and vertical drainage problems of surface water and groundwater within the restricted roadbed, ensure smooth drainage within the roadbed, and improve the long-term performance of the roadbed structure. The protective part 4 mainly ensures the safety and stability of the existing buildings 7 and the existing railway 8 during the construction process. The monitoring system is mainly divided into deformation monitoring of the existing buildings 7 and the existing railway 8 and the surrounding surface. Its main function is to solve whether the roadbed deformation meets the specifications during the construction, commissioning and operation of the restricted roadbed and monitor the impact of the existing buildings 7 and the existing railway 8.

[0091] The construction method of the protective structure provided in this application includes:

[0092] Construction preparation: pre-construction work such as site cleaning, leveling and measurement.

[0093] Monitoring system construction;

[0094] Drainage system construction: Construction of the line drainage section 50 to ensure smooth drainage of the construction site during construction;

[0095] Construction of the protection section: Build a protective structure 1 adjacent to the existing railway 8. Set up construction safety isolation racks on the inner side of the road shoulders 11 on both sides of the existing building 7. The second pile 40 should be welded together in a row using connecting beams 41 and hung with protective nets to enhance construction safety and operational safety of the existing railway 8.

[0096] Micropile Construction: The top of the micropile 3 is integrally connected to the slab beam 2. Before construction, an on-site process test should be conducted to determine the appropriate pile parameters, construction process, and technical parameters. When the roadbed soil layer is soft soil, micropiles 3 with a reinforced protective casing 31 made of steel pipes are used. When the roadbed soil layer is special rock and soil such as expansive (rock) soil, loess, or saline soil, micropiles 3 with a reinforced steel frame 33 are used.

[0097] Site excavation and underground seepage trench construction;

[0098] Slab beam construction;

[0099] Ballast seepage trench construction;

[0100] Construction of upper road base and subgrade: Carry out filling and compaction construction according to the design drawings, monitor deformation during construction, and put forward reasonable suggestions and countermeasures.

[0101] The present application provides a roadbed protection structure, in which the roadbed of an existing railway 9 is located between an existing railway 8 and an existing building 7, and the protection structure 1 includes a plate beam 2 and micro piles 3. Micro piles 3 are used to reinforce special rock and soil foundations. The micro piles 3 have little disturbance to special rock and soil, can effectively deal with the problem of insufficient bearing capacity of special rock and soil foundations, and have a good treatment effect. The construction of micro piles 3 adopts a 100-type motor drill, a Luoyang shovel or a down-the-hole drill. Compared with the large-scale mechanical equipment required for the construction of conventional pipe piles, cast-in-place piles, etc., it has the advantages of convenient construction and simple site requirements, and the construction with small equipment can speed up the construction progress and effectively save construction time. The protection structure 1 of the present application includes micro piles 3, plate beams 2, a drainage system, a protection part 4 and a monitoring system, and the cost is relatively low, which has a cost advantage. The plate beam 2 structure is also provided with a retaining plate and is cast as a whole with the retaining plate 22, which can effectively protect the stability of the existing buildings on both sides, and the overall effect is good. The monitoring system can promptly identify problems during construction, especially in deformation-sensitive areas such as existing buildings 7. This can prevent impacts on the safety of existing buildings 7 in extreme situations, ensuring the safety of the construction process. The protective structure 1 of this application is suitable for confined roadbed areas in special geotechnical areas such as soft soil, expansive (rock) soil, loess, and saline soil. It can be used to reinforce special geotechnical areas and protect adjacent existing buildings 7. It is convenient to construct, adopts reasonable measures, and saves construction costs.

[0102] The protective structure provided in this application is not only effective in special rock and soil foundation treatment and restricted roadbed sections, but is also applicable to other areas where the foundation bearing capacity does not meet the design requirements and where slope deformation and stability control are strictly controlled. It can safely and effectively solve problems such as insufficient bearing capacity and deformation control, and has a wide range of applications.

[0103] The various embodiments / implementations provided in this application can be combined with each other without causing any contradiction.

[0104] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Persons skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A roadbed protection structure, characterized in that: The roadbed is located between the existing railway and the existing building, and the protective structure includes: A plate beam, laid on the roadbed, plays an optimizing role in the load bearing of the roadbed; and Micro piles are arranged below the plate beam and connected to the plate beam, and the micro piles provide support for the plate beam; The plate beam is arranged at the bottom of the ballast, and the plate beam comprises: a plate body, laid on the roadbed; and The stress-bearing steel bars are arranged in the plate body and connected with the micro-piles. The plate beam also includes a supporting plate, which is protrudingly arranged on a side of the plate body close to the existing building.

2. The protective structure according to claim 1, characterized in that: The micro pile comprises: A first pile body is arranged below the plate beam and connected to the plate beam; and The reinforcement body is arranged on the first pile body to reinforce the first pile body.

3. The protective structure according to claim 2, characterized in that: The reinforcement body is a protective sleeve, the protective sleeve is formed with a plurality of holes, and the first pile body is cast in the protective sleeve.

4. The protective structure according to claim 3, characterized in that: The protective sleeve is provided with a circle of holes at intervals of 20 cm to 50 cm in the longitudinal direction, each circle of holes has 3 to 4 holes, and the diameter of the holes is 1 cm to 2 cm.

5. The protective structure according to claim 3, characterized in that: The micro pile further comprises a reinforcing steel bar, one end of which is arranged on the upper part of the first pile body, and the other end of which is connected and fixed to the plate beam.

6. The protective structure according to claim 2, characterized in that: The reinforcement body is a steel bar frame, which is arranged inside the first pile body, with one end arranged at the bottom of the first pile body and the other end protruding from the top of the first pile body and connected and fixed to the plate beam.

7. The protective structure according to claim 6, characterized in that: The steel bar frame includes 3 to 4 longitudinal steel bars, one end of which is arranged at the bottom of the first pile body, and the other end protrudes from the top of the first pile body and is connected and fixed to the plate beam. The diameter of the longitudinal steel bar is 8 mm to 16 mm.

8. The protective structure according to claim 7, characterized in that: The steel bar frame further comprises stirrups for bundling and fixing the longitudinal steel bars, wherein the diameter of the stirrups is 6 mm to 10 mm; and / or The longitudinal steel bars are evenly arranged in the first pile body in a triangle or a quadrilateral.

9. The protective structure according to claim 2, characterized in that: The length of the first pile body is 4m-10m, the diameter of the first pile body is 0.15m-0.3m, and the spacing between the first pile bodies is 0.5m-1.2m.

10. The protective structure according to claim 2, characterized in that: The first piles are evenly arranged in a triangle or square shape along the bottom of the plate beam.

11. The protective structure according to claim 1, characterized in that: The length of each section of the plate is 4m to 6m, the thickness is 0.4m to 0.6m, and the width is 4m to 6m; and / or A structural seam is formed between adjacent plates.

12. The protective structure according to claim 1, characterized in that: The top surface of one side of the plate body close to the existing building is lower than the top surface of the other side.

13. The protective structure according to claim 1, characterized in that: The width of the support plate is 0.3m to 0.8m, and the height of the support plate is 0.6m to 2m.

14. The protective structure according to claim 1, characterized in that: The protection structure also includes a protection part, which is arranged between the roadbed and the existing railway, and between the supporting plate with a height greater than 1m and the existing building.

15. The protective structure according to claim 14, characterized in that: The protection part comprises: A second pile body, one end of which is disposed in the roadbed and the other end of which is exposed outside the roadbed; and A connecting beam is connected between the upper parts of at least two of the second pile bodies.

16. The protective structure according to claim 15, characterized in that: The spacing between the second pile bodies is 0.3m to 0.5m, and the length of the second pile body is 2 to 2.5 times the excavation depth of the foundation pit of the slab beam.

17. The protective structure according to claim 1, characterized in that: The protective structure further includes a line drainage portion, which is arranged outside the existing building; and / or The protective structure further comprises an underground seepage ditch, which is arranged at the intersection of the lower part of the plate beam and the existing railway; and / or The protective structure also includes a ballast seepage ditch, which is arranged on the top surface of the plate beam adjacent to the supporting plate.

18. The protective structure according to claim 1, characterized in that: The protective structure further includes a surface observation pile, which is arranged on the ground on a side of the plate beam close to the existing building; and / or An existing railway observation pile is arranged on the shoulder of the existing railway on a side of the plate beam close to the existing railway; and / or The existing building observation point is set on the existing building.

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