Concrete sleeper, preparation device, preparation method and installation method

Abstract

The invention provides a concrete sleeper, a preparation device, a preparation method and a mounting method.The concrete sleeper comprises a body, the body is of a concrete structure, the toughness index of concrete is larger than or equal to 8, the body is of a uniform-section structure in the longitudinal direction, a groove is formed in the bottom face of the body and is of a uniform-section structure in the longitudinal direction, and an opening of the groove faces downwards; prestress is arranged in the body in a penetrating mode, the prestress is arranged in the longitudinal direction of the body, the groove is used for being filled with railway ballasts, and a connecting hole is formed in the top face of the body. The structure can effectively reduce the vibration of the sleeper when a train runs, grooves can be arranged without increasing or obviously increasing the height or width of the sleeper, original densely-arranged steel bars can be omitted, the weight can be obviously reduced, the manufacturing, transportation and installation cost can be obviously saved, the ballast bed resistance can be improved, the ballast bed laying requirement is lowered, and the construction efficiency is improved. The sleeper is flat and regular in appearance and slotting, simple in structure and particularly suitable for large-gradient lines in mountainous areas.

Description

Technical Field

[0001] The invention relates to the technical field of rail transit, in particular to a concrete sleeper, a preparation device, a preparation method and an installation method. Background Art

[0002] As railway construction continues to extend to mountainous areas, rack rails have become the core technology of mountain rail transit because of their greater climbing ability (the slope of ordinary railways is 6‰~12‰, and the slope of rack rails can reach 480‰), which can shorten the length of route extension and reduce project investment. However, the mountainous environment places strict requirements on the sleepers of the rack rail system: ① The steep slope sections in mountainous areas will aggravate the longitudinal force of the track, which may easily lead to problems such as sleeper displacement and rail creep, and the shear resistance and ballast resistance of the sleepers are extremely high. ② The plateau mountainous areas (such as the western Sichuan plateau) have strong ultraviolet rays during the day, low temperatures and strong winds at night, and large temperature differences between day and night (exceeding 30°C in some areas). The sleeper material must have excellent thermal stability to avoid excessive deformation under the action of temperature differences that affect the safety of the rail system. ③ Operation and maintenance in remote mountainous areas are difficult, and the sleeper material has the characteristics of high durability and easy maintenance.

[0003] Although steel sleepers are light and easy to install, they face the following key technical bottlenecks in mountainous environments: ① The friction coefficient between steel sleepers and ballast is low (μ≈0.3~0.5, only 50% of that of concrete sleepers), which makes it difficult to resist the longitudinal sliding force of mountain rack trains when climbing large longitudinal slopes, and easily causes track structure instability; and under the long-term repeated action of large longitudinal forces, thin-walled shell steel sleepers are prone to instability and fatigue, making it difficult to ensure the safe operation of mountain rack trains. ② The linear expansion coefficient of steel sleepers is larger than that of concrete. In the large temperature difference environment of plateau mountainous areas, millimeter-level expansion deformation will occur, which may cause the track gauge deviation to exceed the limit, threatening the rack-rail meshing accuracy and train operation safety. ③ High humidity in mountainous areas (average annual humidity > 80%) and acid rain environment, coupled with long-term water accumulation in ballast, will accelerate the corrosion of steel. The life of steel sleepers is less than 10 years and needs to be replaced frequently (concrete sleepers have a life of > 50 years). It is difficult to maintain in remote mountainous areas, and the operation and maintenance cost is 3 to 5 times that of concrete sleepers. ④ The price of steel is much higher than that of concrete materials, and the construction investment cost is high. Due to the above technical defects, steel sleepers are currently only temporarily used for emergency repairs or short-term projects. The steel sleepers in the past lines have been gradually replaced by concrete sleepers. At present, my country's railways have fully turned to concrete sleepers.

[0004] However, the following problems still exist in the application of traditional concrete sleepers in mountain rail transit scenarios: ① Concrete sleepers are heavy and difficult to transport and install, making them unsuitable for the complex construction environment in mountainous areas; ② Traditional concrete sleepers are made of C60 ordinary concrete, which has poor elasticity and toughness, poor train load buffering performance, and often crack and break at corners under repeated loads, reducing durability; ③ On steep sections, in order to ensure sufficient ballast resistance to resist longitudinal slippage of the track, additional texture structures, raised structures, and resistance-enhancing pads are required at the bottom of the sleepers, and usually anchoring devices are also required, which requires high ballast laying; ④ Traditional concrete sleepers have many sudden changes in cross-section and complex structures, making it difficult to control the quality of concrete during production and preparation; and steel bars are required, which increases the process and cost.

[0005] In summary, the existing concrete sleeper technology has insufficient advantages in terms of construction cost, stress performance, transportation and installation convenience, service durability, etc., and needs further optimization. It is urgent to develop a new type of concrete sleeper technology with light structure, simple production, convenient transportation and installation, reliable stress, long service life and durability. Summary of the invention

[0006] The purpose of the present invention is to solve the problem that concrete sleepers in the prior art need to be equipped with resistance-increasing measures on the bottom surface when used in mountainous slope scenarios and their large mass makes transportation and installation difficult. A concrete sleeper, a preparation device, a preparation method and an installation method are provided to achieve functional requirements such as small dead weight, simple structure, convenient preparation and installation, reliable force, long life and durability.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is: A concrete sleeper comprises a body, wherein the body is a concrete structure, the toughness index of the concrete is ≥8, the body is a uniform cross-section structure along the longitudinal direction, a groove is provided on the bottom surface of the body, the groove is a uniform cross-section structure along the longitudinal direction, the opening of the groove faces downward, a prestress is passed through the body, the prestress is arranged along the longitudinal direction of the body, the groove is used to fill ballast, and the top surface of the body has a connecting hole.

[0008] The toughness index of concrete is ≥8, that is, the toughness index of concrete at 28d is ≥8, that is, high-toughness concrete materials are used. The toughness index of ordinary concrete is usually 1-5, and the existing technology can meet the toughness index requirements.

[0009] The bite force required for the sleeper can be adjusted by the depth and / or width dimensions of the groove.

[0010] The position and number of the connection holes are determined according to the tracks to be connected (such as the number of rails, track gauge, and whether there is a rack rail). It can also be set to a unified structure, and the corresponding connection holes are used for track installation according to the actual track installation needs.

[0011] By using the concrete sleeper described in the present invention, the elasticity of the sleeper can be improved through the high-toughness concrete, so that the stiffness of the sleeper and the rail can be more matched, which can better buffer the train load and reduce the vibration of the sleeper when the train is running; at the same time, the high-toughness concrete sleeper has good crack resistance, which can reduce the damage to the edges and corners during transportation and installation, as well as the cracking and spalling damage caused by repeated vibration and impact of the train, and improve durability. With prestressing, the crack resistance of concrete sleepers is further improved, so that concrete sleepers can be grooved without increasing or significantly increasing the height or width of sleepers, and the original densely arranged steel bars can be eliminated, saving the amount of steel bars, eliminating the steel bar binding process, and facilitating production and manufacturing. The setting of the groove can also significantly reduce weight and save manufacturing, transportation and installation costs. Since the groove contacts the ballast, the contact area is significantly increased under the same cross-sectional size, and the roadbed resistance is improved. The groove can also generate a bite force with the ballast. In addition, the groove has side walls in the transverse and longitudinal directions, which can provide good anti-slip ability in the transverse and longitudinal directions, so that the sleepers no longer need to be set with sudden cross-sections and resistance-increasing measures, and the requirements for roadbed laying are reduced. As a result, the shape of the sleepers and the grooves are flat and regular, the structure is simple, and the preparation, transportation and stacking are convenient, which reduces the difficulty of concrete pouring control and the difficulty of prestressing arrangement.

[0012] Compared with the sleepers in the prior art, when laying on a flat surface, it is necessary to add a texture structure, a raised structure or a resistance-increasing cushion layer. When laying on a slope exceeding 12‰, it is necessary to set up an anchoring structure extending into the ballast and the foundation. This structure can provide a large and reliable bite force and can be laid directly without the need for additional anchoring devices. It is particularly suitable for use on steep slope lines in mountainous areas.

[0013] The thickness of the main body may be 6-8 cm, and the thickness of the top surface of the main body may gradually decrease from both ends to the middle.

[0014] To ensure the load-bearing performance of the sleeper, the thickness of the top surface at the rail can be higher than that in the middle part, further reducing the amount of concrete. The extent of reduction is determined based on actual needs, and no gradual change is required, which is more convenient for processing and mold manufacturing.

[0015] The width of the body along the longitudinal direction of the line may gradually decrease from the bottom surface to the top surface.

[0016] That is, the cross-section of the sleeper is in a shape with the bottom enlarged, which is beneficial for balancing stability and reducing the amount of concrete used.

[0017] Preferably, the side walls and the top wall of the main body arranged in the longitudinal direction are both provided with the prestressing force, the prestressing force is arranged symmetrically about the center line of the cross section, and the distance between two adjacent prestressing forces is greater than the maximum particle size of the concrete.

[0018] Preferably, the prestressing arrangement is carried out by a model

[0019] ; ; St

[0020] to determine; in, n represents the amount of prestressing force, e represents the distance between the position of the resultant force of the prestress and the center of gravity, , It represents the tensile stress generated at the lower edge of the section under the rail under positive moment loading condition. T represents the tensile force of each prestressing force, A is the cross-sectional area of ​​the sleeper, I is the bending moment of inertia of the sleeper section, y 1 represents the distance between the lower edge of the sleeper section and the center of gravity. , M 1 represents the external load under the rail section under positive moment loading condition F and the positive bending moment of the rail section under the action of the sleeper's own weight, q is the weight per linear meter of the sleeper, L Indicates the standard support span; , It represents the tensile stress generated on the upper edge of the cross section under the negative moment loading condition in the pillow middle section. y 2 represents the distance between the upper edge of the sleeper section and the center of gravity. , M 2 represents the external load under the negative moment loading condition of the pillow middle section F and the positive bending moment of the rail section under the action of the sleeper's own weight; Indicates the maximum design tensile stress of the sleeper.

[0021] After a large number of experimental studies on the optimization calculation of prestressed arrangement of this structural form in various scenarios such as ordinary railways, high-speed railways, and rack railways, the constraint conditions of this structure can be controlled below 5MPa, and the reliability is relatively high.

[0022] Preferably, the tensile strength of the concrete material according to ≤ Sure, is the partial factor of concrete material.

[0023] According to the prior art and experience, the partial coefficient usually needs to be more than 2, and the solution of the present application can be 1.4-2.

[0024] Preferably, the mechanical engagement force between the groove of the concrete sleeper and the ballast is F saccording to

[0025] and

[0026] To confirm, Indicates the lateral resistance value of the sleeper and ballast. Indicates the longitudinal resistance value of the sleeper and ballast. is the standard value of the friction between the sleeper concrete surface and the ballast. is the shear slip strength value between ballast and crushed stone layers, F 1 represents the friction force on both sides of the sleeper surface, Indicates the friction force on the surfaces of the sleepers at both ends. F 2 represents the friction force on the bottom surface of the sleeper, F 3 represents the friction force on the inner surface of the groove, h2 represents the depth of the groove, b1 represents the thickness of the sleeper, b2 represents the width of the groove, Indicates the thickness of the sleeper end plate, A represents the length of the sleeper and B represents the width of the sleeper.

[0027] Preferably, the bottom surface of the body further has a bracket, the bracket is used to support a baffle, and the baffle is used to cover the opening of the groove.

[0028] The structure of the bracket can be as simple as possible, such as angle brackets, bent steel bars, and trough structures across the two sides of the trough, as long as it is easy to support the baffle so that the baffle will not fall when the sleeper is turned over, thereby avoiding the leakage of the filled ballast. When the sleeper is installed later, the bracket can also be used as a resistance-increasing component to further increase the resistance of the sleeper and improve reliability.

[0029] A preparation device for a concrete sleeper, used for preparing a concrete sleeper as described above, comprising a first shell, a second shell, a reaction frame, a tension anchor plate and an anchor, wherein the first shell is used for forming the top surface and side surfaces of the concrete sleeper, and the second shell is used for forming the groove of the concrete sleeper, the first shell is a bottom mold, and the second shell is a top mold, and there is a spacing between the top surface of the first shell and the top surface of the second shell, and the shape and size of the spacing are adapted to the shape and size of the bottom surface of the concrete sleeper.

[0030] By using the preparation device of the concrete sleeper described in the present invention, the preparation is carried out by inverting the first shell and the second shell, less template material is used, the molding quality of the groove is better, no additional pouring port is required, and it is easier to fill densely, which is beneficial to ensuring the molding quality of the concrete sleeper.

[0031] Preferably, first connecting members are respectively provided on both longitudinal sides of the top surface of the first shell, and second connecting members are respectively provided on both longitudinal sides of the top surface of the second shell, and the first connecting member and the second connecting member are connected by bolts.

[0032] By overlapping the first connecting member and the second connecting member respectively arranged on the first shell and the second shell, the first shell can support the second shell, so there is no need to set up additional supporting components. The connection with the matching bolts can lock the relative positions of the two, ensuring the reliability of casting and low mold cost.

[0033] A method for preparing a concrete sleeper, applied to the concrete sleeper or the device for preparing the concrete sleeper, comprises the following steps: S1, installing the first shell, the second shell, the prestressing force, the reaction frame, the tension anchor plate and the anchor; S2, tensioning the prestress; S3, pouring concrete from the distance between the top surface of the first shell and the top surface of the second shell; S4. After curing and forming, the formwork is removed to complete the preparation of concrete sleepers.

[0034] The method for preparing a concrete sleeper described in the present invention is convenient for casting, dense filling, and pre-embedding of brackets. It is also convenient to complete the filling and vibration of ballast in the prefabrication stage to ensure that a reliable bite force is effectively formed between the ballast and the groove, which is convenient for direct installation and saves processing space on the construction site.

[0035] Preferably, a pre-embedded bracket is also included before the concrete sleeper is formed.

[0036] A method for installing a concrete sleeper, applied to a concrete sleeper as described above, or a sleeper prepared by using a concrete sleeper preparation device as described above, or a concrete sleeper prepared by using a concrete sleeper preparation method as described above, comprises the following steps: A. Filling the groove of the inverted concrete sleeper with ballast and temporarily closing the opening of the groove; B. installing the concrete sleeper at a preset position; C. releasing the temporary closure of the groove; D. The concrete sleeper is vibrated to complete the installation of the concrete sleeper.

[0037] The method for installing a concrete sleeper described in the present invention ensures the filling quality of the ballast, enhances the stability of the sleeper in use, and is convenient for the filled ballast to avoid spilling or loosening during transportation or turning, thereby affecting the bite force. After installation, the ballast can be vibrated to compact the sleeper body again, and the pre-filled ballast can be shifted and exchanged with the ballast on site to form a whole, thereby further enhancing the embedding and bite effect of the groove structure.

[0038] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The concrete sleeper of the present invention can effectively reduce the vibration of the sleeper when the train is running. The high-toughness concrete is combined with prestressing, and the groove can be set without increasing or significantly increasing the height or width of the sleeper. The original densely arranged steel bars can be eliminated, and the weight can be significantly reduced and the manufacturing, transportation and installation costs can be saved. The roadbed resistance can also be improved, thereby reducing the roadbed laying requirements. The shape and groove of the sleeper are also easy to design flat and regular, with a simple structure, convenient preparation, transportation and stacking, further reducing the difficulty of concrete pouring control and the difficulty of prestressing arrangement. It is particularly suitable for use on steep slope lines in mountainous areas.

[0039] 2. The concrete sleeper preparation device of the present invention is used to prepare the concrete sleeper by inverting the first shell and the second shell. Less template material is used, the groove molding quality is better, no additional pouring port is required, and it is easier to fill densely, which is beneficial to ensuring the molding quality of the concrete sleeper.

[0040] 3. The method for preparing a concrete sleeper described in the present invention is convenient for casting, dense filling, and pre-embedding of brackets. It is also convenient to complete the filling and vibration of ballast in the prefabrication stage to ensure that a reliable bite force is effectively formed between the ballast and the groove, which is convenient for direct installation and saves processing space on the construction site.

[0041] 4. The installation method of a concrete sleeper described in the present invention ensures the filling quality of the ballast, enhances the stability of the sleeper in use, and is convenient for the filled ballast to avoid spilling or loosening during transportation or turning, which affects the bite force. After installation, the ballast is vibrated to compact the sleeper body again, and the pre-filled ballast can be shifted and exchanged with the ballast on site to form a whole, further improving the embedding and bite effect of the groove structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a schematic elevation view of a concrete sleeper of Example 1; Figure 2 is a top view schematic diagram of a concrete sleeper of Example 1; Figure 3is a bottom view schematic diagram of a concrete sleeper of Example 1; Figure 4 This is a schematic cross-section of a concrete sleeper of Example 1. Figure 1 ; Figure 5 This is a schematic cross-sectional view of a concrete sleeper of Example 1. Figure 2 ; Figure 6 It is a schematic diagram of the positive moment loading condition of the rail section; Figure 7 It is a schematic diagram of the negative moment loading condition in the pillow mid-section; Figure 8 It is a cross-sectional schematic diagram of the prestressing arrangement of the sleeper; Fig. 9 It is a schematic diagram of the three-dimensional structure of a preparation device for a concrete sleeper according to Example 2; Fig.10 is a schematic cross-sectional view of a device for preparing a concrete sleeper in Example 2; Fig.11 This is a schematic diagram of the steps of a method for installing a concrete sleeper in Example 3. Figure 1 ; Fig.12 This is a schematic diagram of the steps of a method for installing a concrete sleeper in Example 3. Figure 2 ; Figure 13(a) is a schematic diagram of the stress distribution on the upper edge of the pillow section under bending conditions; Figure 13(b) is a schematic diagram of the stress distribution at the lower edge of the pillow mid-section under bending conditions; Figure 14(a) is a schematic diagram of the stress distribution on the upper edge of the rail section under bending conditions; Figure 14(b) is a schematic diagram of the stress distribution at the lower edge of the rail section under bending conditions; FIG15( a ) is a schematic diagram of the elevation dimensioning of the sleeper; Figure 15(b) is a schematic diagram of the cross-sectional dimension marking of the sleeper.

[0043] Icon: 1-main body; 11-groove; 12-prestressed force; 13-connecting hole; 14-bracket; 15-baffle; 21-first shell; 22-second shell; 231-first connecting piece; 232-second connecting piece; 24-bolt; 31-reaction frame; 32-tensioning anchor plate; 33-anchor. DETAILED DESCRIPTION

[0044] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0045] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0046] Unless otherwise specified, in the description of the specific embodiments of the present invention, the terms indicating the orientation or position relationship such as "up", "down", "left", "right", "center", "inside", "outside", etc. are all expressions based on the orientation or position relationship shown in the drawings, or are the orientation or position relationship when the invented product / equipment / device is usually used. These terms of orientation or position relationship are only for the convenience of describing the scheme of the present invention or simplifying the description in the specific embodiments, so as to facilitate the technicians to quickly understand the scheme, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the present invention.

[0047] In addition, if the terms "horizontal", "vertical", "overhanging", "parallel" and the like appear, it does not mean that the corresponding devices / components / elements are required to be absolutely horizontal or vertical or overhanging or parallel, but may be slightly tilted or have deviations. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but may be slightly tilted. Alternatively, it can be simplified to mean that the corresponding devices / components / elements are set in directions such as "horizontal", "vertical", "overhanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its role in the scheme of the present invention.

[0048] In addition, the expressions “first”, “second”, “third”, etc., which appear in the terms, are merely used to distinguish the description of the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0049] In addition, in the description of the embodiments of the present invention, "several", "plurality" and "a number" represent at least 2. It can be any number such as 2, 3, 4, 5, 6, 7, 8, 9, and even more than 9.

[0050] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threading, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0051] Example 1 like Figure 1-Figure 8 As shown, a concrete sleeper used in the present invention comprises: It includes a main body 1, which is a concrete structure with a toughness index of concrete ≥ 8. The main body 1 is a uniform cross-sectional structure along the longitudinal direction. A groove 11 is provided on the bottom surface of the main body 1. The groove 11 is a uniform cross-sectional structure along the longitudinal direction. The opening of the groove 11 faces downward. A prestress 12 is penetrated in the main body 1 and arranged along the longitudinal direction of the main body 1. The groove 11 is used to fill ballast. The top surface of the main body 1 has a connecting hole 13.

[0052] For example, according to the existing sleeper height of 235mm, the width is 210mm in the middle of the sleeper, and gradually changes to 306.5mm at both ends. The top edge of the sleeper changes frequently, and the cross-section changes a lot. Stirrups, steel bars and prestressed structures must be set inside. The concrete sleeper structure of the present invention can achieve the same mechanical properties, and the sleeper height can be reduced to 160mm, the equal width is designed to be 258mm, and the structural appearance is flatter and more regular. The side walls and top walls of the main body 1 are arranged along the longitudinal direction, and a row of prestressed 12 is provided. Figure 4-Figure 5 As shown, the prestressing forces 12 are arranged symmetrically about the center line of the cross section, and the distance between two adjacent prestressing forces 12 is greater than the maximum particle size of concrete, such as the distance ≥ 2 cm.

[0053] The wall thickness of the body 1 can be determined according to the standard bending loading condition adopted in the national standard specification (such as "Concrete Sleepers for Ballasted Track Sleepers (GB / T 37330-2019)"). The wall thickness size can simultaneously meet the stress requirements of the middle section of the sleeper and the section under the rail to meet the crack resistance and ultimate bearing capacity. For example, if the thickness of the body 1 is 6-8cm, the body 1 can have the same thickness everywhere, or the thickness of each side surface can be determined according to actual measurement. The top surface thickness of the body 1 gradually decreases from the two ends to the middle. The depth of the groove 11 can be unchanged in the longitudinal direction, while the top surface height of the body 1 gradually decreases toward the middle, such as Figure 1 As shown, the height of the top surface of the body 1 may remain unchanged in the longitudinal direction while the depth of the groove 11 gradually increases toward the middle.

[0054] The width of the body 1 along the longitudinal direction of the line gradually decreases from the bottom surface to the top surface. Figure 4-Figure 5 As shown, the width of the corresponding groove 11 along the longitudinal direction of the line can be changed in a coordinated manner, which is helpful to improve the bite force and can also reduce the amount of concrete used.

[0055] Compared with the traditional concrete sleepers, the technical and economic indicators of the sleepers of the present invention are calculated as follows: Table 1 Comparison of technical and economic performance between conventional concrete sleepers and sleepers of the present invention

[0056] The prestressing force 12 is arranged in the main body 1, firstly, to provide pre-compression stress for the pillow body, so that the tensile stress level of the pillow body during the use stage is sufficiently small, further improving the anti-cracking performance of the pillow body; secondly, to provide bearing capacity for the cross section, and improve the bending bearing capacity of the pillow body.

[0057] The arrangement principle of prestressing force 12 is to adjust the number of prestressing force 12 n and location e , so that the tensile stress level under the positive moment loading condition of the rail section and the negative moment loading condition of the sleeper section are as small as possible, so as to reduce the risk of cracking of the sleeper under load. At the same time, on the basis of meeting the anti-cracking safety, the prestressing amount is required to be n As little as possible to reduce the amount of prestressing of the sleeper and reduce costs. The constraint condition is the maximum tensile stress of the sleeper. The applicant has conducted a large number of experimental studies and demonstrated that the tensile stress level of the sleeper structure of the present invention is Not higher than 5MPa, that is, the constraint condition can be set to ≤5MPa for trial calculation.

[0058] The prestressing 12 arrangement can be obtained through the model

[0059] ; ; St

[0060] to determine; in, n represents the amount of the prestressing force 12, e Indicates the distance between the position of the resultant force of the prestress 12 and the center of gravity (see Figure 8 ), , express Figure 6 The tensile stress generated at the lower edge of the section under the rail under positive bending moment loading condition, T represents the tensile force of each of the prestressing forces 12, A is the cross-sectional area of ​​the sleeper, I is the bending moment of inertia of the sleeper section, y1 represents the distance between the lower edge of the sleeper section and the center of gravity (see Figure 8 ), , M 1 represents the external load under the rail section under positive moment loading condition F and the positive bending moment of the rail section under the action of the sleeper's own weight, q is the weight per linear meter of the sleeper, L Indicates the standard support span; , express Figure 7 The tensile stress generated on the upper edge of the cross section under negative moment loading in the pillow middle section, y 2 represents the distance between the upper edge of the sleeper section and the center of gravity (see Figure 8 ), , M 2 represents the external load under the negative moment loading condition of the pillow middle section F and the positive bending moment of the rail section under the action of the sleeper's own weight; Indicates the maximum design tensile stress of the sleeper, which is 5MPa.

[0061] After obtaining the optimal prestressing bundle arrangement scheme, the crack resistance of the sleeper structure should meet the following requirements: the tensile strength of the concrete material according to ≤ Sure, is the partial factor of concrete material.

[0062] According to the prior art and experience, the partial coefficient usually needs to be more than 2, and the solution of the present application can be 1.4-2.

[0063] In order to verify the load-bearing capacity of the new sleeper of the present invention, the load-bearing capacity of the sleeper of the present invention is analyzed and verified by adopting the standard loading mode required by the relevant specifications. Figure 6 The rail section and Figure 7 The middle section of the pillow was subjected to a bending loading condition and a cracking test with a load of 10.2 tons. According to Figures 13(a) and 13(b), the maximum compressive stress at the upper edge of the middle section of the pillow is -27.3MPa, which is much smaller than the compressive strength of the high-toughness concrete; the maximum tensile stress at the lower edge is 4.90MPa. Even if the partial coefficient of this application is 1.4, the tensile strength of the concrete can stably reach 7MPa, and the anti-cracking safety is relatively high, which meets the requirements of the specification; according to Figures 14(a) and 14(b), the maximum compressive stress at the upper edge of the lower section of the rail is -25.5MPa, which is much smaller than the compressive strength of the concrete of this application; the maximum tensile stress at the lower edge is 3.79MPa, which can also meet the requirements of the specification and has a high anti-cracking safety.

[0064] For example, according to the requirements of the Railway Track Design Specification (TB 10082 - 2017), the longitudinal resistance value of concrete sleepers and ballast is ≥10kN, and the transverse resistance value is ≥9kN. The traditional concrete sleepers provide only the friction between the bottom and side surfaces of the sleepers and the ballast. The sleepers of the present invention rely on the friction between the bottom, side surfaces, inner surface of the groove and the ballast gravel, as well as the mechanical bite force between the concave structure of the groove and the convex structure of the ballast, and have more resistance-increasing factors. The ballast outside the sleeper can be filled to the top of the groove 11.

[0065] The sleeper mainly realizes the resistance of the roadbed through the bite force between the groove 11 and the ballast. The mechanical bite force between the groove 11 and the ballast F s according to

[0066] and

[0067] To confirm, Indicates the lateral resistance value of the sleeper and ballast. Indicates the longitudinal resistance value of the sleeper and ballast. It is the standard value of the friction resistance between the sleeper concrete surface and the ballast, which is related to the surface roughness, ballast particle size gradation, ballast density, etc. It can be obtained through experiments and is generally 15~30kPa. It is the shear slip strength value between ballast crushed stone layers, which is related to the ballast particle size gradation, ballast density, etc. It can be obtained through experiments and is generally 30~60kPa. F 1 represents the friction force on both sides of the sleeper surface, Indicates the friction force on the surfaces of the sleepers at both ends. F 2 represents the friction force on the bottom surface of the sleeper, F 3 represents the friction force on the inner surface of the groove 11, h2 represents the depth of the groove 11, b1 represents the thickness of the sleeper, b2 represents the width of the groove 11, Indicates the thickness of the sleeper end plate, represents the length of the sleeper, and B represents the width of the sleeper, as shown in Figures 15(a) and 15(b).

[0068] Taking the structural dimensions of the embodiment as an example, the sleeper length l =2000mm, sleeper width B=258mm, groove 11 width b2=138mm, groove 11 depth h2=90mm, vertical end plate thickness a =60mm, sleeper thickness b1=60mm. For safety considerations, Take 15kPa, Take 30kPa. Substituting into the above two formulas, we get: F横 =25.75kN>9kN F 纵 =16.34kN>10kN The resistance of the ballast bed is much greater than the requirements of the specification. According to the above-mentioned ballast bed resistance, it can be applied to the laying of a slope of 140‰. It shows that the sleeper provided by the present invention increases the friction area between the sleeper and the ballast and provides mechanical bite force through the groove structure, and the resistance-increasing effect is obvious. That is, the bite force can be adjusted to meet the design requirements by adjusting the width and / or depth of the groove 11. The size of the concrete sleeper of the present application will not increase the height or thickness due to the provision of the groove 11. It is particularly suitable for use on lines with large slopes in mountainous areas and has good promotion prospects.

[0069] In some optional embodiments, the bottom surface of the body 1 further has a bracket 14, the bracket 14 is used to support a baffle 15, and the baffle 15 is used to cover the opening of the slot 11. Fig.11 shown.

[0070] The structure of the bracket 14 can be as simple as possible, such as angle brackets, bent steel bars, and a groove-shaped structure across both sides of the groove 11, as long as it is easy to support the baffle 15 so that the baffle 15 will not fall when the sleeper is flipped, thereby avoiding the leakage of the filled ballast. When the sleepers are subsequently installed, the bracket 14 can also be used as a resistance-increasing component to further increase the resistance of the sleepers and improve reliability. In this embodiment, the bracket 14 is exemplified by a plurality of symmetrically arranged L-shaped steel bars facing inward. The size of the sleepers and the amount of concrete used can be further reduced, reducing costs and the difficulty of transportation and construction in mountainous areas. The bracket 14 is set in the concrete, and there is no need to set a sudden cross section for installation.

[0071] The concrete sleeper described in the present invention is used to effectively reduce the vibration of the sleeper when the train is running. The high-toughness concrete is combined with the prestressed material 12, and the groove 11 can be set without increasing or significantly increasing the height or width of the sleeper. The original densely arranged steel bars can be eliminated, and the weight can be significantly reduced and the manufacturing, transportation and installation costs can be saved. The roadbed resistance can also be improved, thereby reducing the roadbed laying requirements. The shape and grooving of the sleeper are also easy to design with flat rules and simple structure, which is convenient for preparation, transportation and stacking, further reducing the difficulty of concrete pouring control and the difficulty of prestressing arrangement. It is particularly suitable for use on steep slope lines in mountainous areas.

[0072] Example 2 A preparation device for a concrete sleeper according to the present invention is used to prepare a concrete sleeper as described in Example 1, comprising a first shell 21, a second shell 22, a reaction frame 31, a tension anchor plate 32 and an anchor 33, wherein the first shell 21 is used to form the top surface and side surfaces of the concrete sleeper, and the second shell 22 is used to form the groove 11 of the concrete sleeper, the first shell 21 is a bottom mold, and the second shell 22 is a top mold, and there is a spacing between the top surface of the first shell 21 and the top surface of the second shell 22, and the shape and size of the spacing are adapted to the shape and size of the bottom surface of the concrete sleeper, such as Figure 9-10 shown. The first shell 21 and the second shell 22 are both configured according to the shape and size of the sleeper. The first shell 21 and the second shell 22 are preferably assembled structures, such as using butt bolts to assemble the plates, and the material can be steel structure.

[0073] The first shell 21 can be placed on a vibration table for preparation, so as to facilitate the vibration of concrete and ballast. The filling of ballast can be carried out in the prefabrication stage of the factory, which reduces the on-site construction procedures and improves the density and quality of ballast filling.

[0074] The second shell 22 can be relatively fixed to the first shell 21 through other supporting members, or first connecting members 231 can be respectively provided on both sides of the top surface of the first shell 21, preferably symmetrically distributed, and second connecting members 232 can be respectively provided on both sides of the top surface of the second shell 22, and the first connecting member 231 and the second connecting member 232 are connected by bolts 24. Therefore, there is no need to set up additional supporting members, and the connection with the bolts 24 can lock the relative positions of the two, ensuring the reliability of casting, and low mold cost. The first connecting member 231 and the first shell 21 may be connected or may be integrally formed, and the second connecting member 232 and the second shell 22 may be connected or may be integrally formed.

[0075] The first shell 21 and the second shell 22 are placed in the middle of the two reaction frames 31, and the axes of the two reaction frames 31 are at the same height as the axes of the first shell 21 and the second shell 22 as a whole, avoiding eccentric compression under prestressing, which affects the deformation and force safety of the tooling.

[0076] In some optional embodiments, the reaction frame 31 can be made of steel tube concrete material, which has the advantages of high compressive strength and high rigidity, can be constructed to withstand compression deformation, reduce prestress loss, and increase effective prestress.

[0077] By using the concrete sleeper preparation device of the present invention, the first shell 21 and the second shell 22 are inverted for preparation, less template material is used, the molding quality of the groove 11 is better, no additional pouring port is required, and it is easier to fill densely, which is conducive to ensuring the molding quality of the concrete sleeper. Example 3 A method for preparing a concrete sleeper adopted in the present invention is applied to a preparation device for a concrete sleeper as in Example 1 or a concrete sleeper as in Example 2, and comprises the following steps: S1, installing the first shell 21, the second shell 22, the prestressing force 12, the reaction frame 31, the tension anchor plate 32 and the anchor 33; S2, tensioning the prestress 12; S3, pouring concrete from the distance between the top surface of the first shell 21 and the top surface of the second shell 22; S4. After curing and forming, the formwork is removed to complete the preparation of concrete sleepers.

[0078] First, install the first shell 21, the second shell 22, the reaction frame 31, the tension anchor plate 32 and the anchor 33 in place, and penetrate the prestress 12 at the corresponding position, and then tension the prestress 12. After tensioning, pour concrete through the gap between the top surface of the first shell 21 and the top surface of the second shell 22. During the pouring process, vibrate with an auxiliary vibrator or a low-frequency attached vibrator. When the coarse aggregate emerges from the top surface of the formwork, it is considered to be poured densely. Cover the top surface of the formwork system with a plastic film, cure and shape under natural conditions, and demould and cut off the prestress 12 after meeting the design requirements.

[0079] When demoulding, the bolts 24 may be removed first, and then the first shell 21 and the second shell 22 may be removed respectively.

[0080] When the bracket 14 needs to be installed, the bracket 14 can be inserted into the concrete before the concrete hardens to achieve pre-embedding.

[0081] The method for preparing a concrete sleeper described in the present invention is convenient for casting, dense filling, and pre-embedding of the bracket 14. It is also convenient to complete the filling and vibration of the ballast in the prefabrication stage to ensure that a reliable bite force is effectively formed between the ballast and the groove 11, which is convenient for direct installation and saves processing space on the construction site.

[0082] Example 4 A method for installing a concrete sleeper is applied to a concrete sleeper as described in Example 1 or to a sleeper prepared by a concrete sleeper preparation device as described in Example 2 or a sleeper prepared by a concrete sleeper preparation method as described in Example 3, such as Figure 11-Figure 12 As shown, it includes the following steps: A. Filling the groove 11 of the inverted concrete sleeper with ballast and temporarily closing the opening of the groove 11; B. installing the concrete sleeper at a preset position; C. Release the temporary closure of the groove 11; D. The concrete sleeper is vibrated to complete the installation of the concrete sleeper.

[0083] There are many options for temporarily closing the opening of the slot 11, such as the overall outer covering of the plate. In this embodiment, a bracket 14 is provided at the bottom of the sleeper to cooperate with the baffle 15 for closing. The bracket 14 can be used as a support, as a pull-out track for the baffle 15, and can also be used as a resistance-increasing measure during installation to further increase the resistance of the track bed. The baffle 15 is used to temporarily close the opening of the slot 11 during transportation and installation to prevent ballast from spilling out. The baffle 15 is inserted from the gap between the bracket 14 and the bottom surface of the sleeper. Step A is performed directly after prefabrication is completed, or it can be filled at the construction site.

[0084] After the sleeper is placed on site, the baffle plate 15 is extracted from the gap between the bracket 14 and the sleeper bottom surface. The baffle plate 15 is a temporary tool and can be reused.

[0085] After the baffle 15 is removed, the concrete sleeper is vibrated, such as by using an attached vibrator, to compact the ballast into one piece and to tightly engage with the bracket 14. Fig.12 shown.

[0086] The method for installing a concrete sleeper described in the present invention ensures the filling quality of the ballast, enhances the stability of the sleeper in use, and is convenient for the filled ballast to avoid spilling or loosening during transportation or turning, thereby affecting the bite force. After installation, the ballast can be vibrated to compact the sleeper body again, and the pre-filled ballast can be shifted and exchanged with the ballast on site to form a whole, thereby further enhancing the embedding and bite effect of the groove structure.

[0087] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A concrete sleeper, characterized in that: The invention comprises a main body (1), wherein the main body (1) is a concrete structure, the toughness index of the concrete is ≥8, the main body (1) is a uniform cross-section structure along the longitudinal direction, a groove (11) is provided on the bottom surface of the main body (1), the groove (11) is a uniform cross-section structure along the longitudinal direction, the opening of the groove (11) faces downward, a prestress (12) is penetrated in the main body (1), the prestress (12) is arranged along the longitudinal direction of the main body (1), the groove (11) is used to fill ballast, and the top surface of the main body (1) has a connecting hole (13).

2. A concrete sleeper according to claim 1, characterized in that: The prestressing force (12) is arranged in a manner as shown in the model ； ； S.t. to determine; in, n represents the amount of the prestressing force (12), e represents the distance between the position of the resultant force acting point of the prestress (12) and the position of the center of gravity, , It represents the tensile stress generated at the lower edge of the section under the rail under positive moment loading condition. T represents the tension force of each of the prestressing forces (12), A is the cross-sectional area of ​​the sleeper, I is the bending moment of inertia of the sleeper section, y 1 represents the distance between the lower edge of the sleeper section and the center of gravity. , M 1 represents the external load under the rail section under positive moment loading condition F and the positive bending moment of the rail section under the action of the sleeper's own weight, q is the weight per linear meter of the sleeper, L Indicates the standard support span; , It represents the tensile stress generated on the upper edge of the cross section under the negative moment loading condition in the pillow middle section. y 2 represents the distance between the upper edge of the sleeper section and the center of gravity. , M 2 represents the external load under the negative moment loading condition of the pillow middle section F and the positive bending moment of the rail section under the action of the sleeper's own weight; Indicates the maximum design tensile stress of the sleeper.

3. A concrete sleeper according to claim 2, characterized in that: Tensile strength of concrete materials according to ≤ Sure, is the partial factor of concrete material.

4. A concrete sleeper according to any one of claims 1 to 3, characterized in that: The mechanical engagement force between the groove (11) of the concrete sleeper and the ballast F s according to and To confirm, Indicates the lateral resistance value of the sleeper and ballast. Indicates the longitudinal resistance value of the sleeper and ballast. is the standard value of the friction resistance between the sleeper concrete surface and the ballast. is the shear slip strength value between ballast and crushed stone layers, F 1 represents the friction force on both sides of the sleeper surface, Indicates the friction force on the surfaces of the sleepers at both ends. F 2 represents the friction force on the bottom surface of the sleeper, F 3 represents the friction force on the inner surface of the groove (11), h2 represents the depth of the groove (11), b1 represents the thickness of the sleeper, b2 represents the width of the groove (11), Indicates the thickness of the sleeper end plate, A represents the length of the sleeper and B represents the width of the sleeper.

5. A concrete sleeper according to claim 4, characterized in that: The bottom surface of the body (1) also has a bracket (14), and the bracket (14) is used to support a baffle (15), and the baffle (15) is used to cover the opening of the groove (11).

6. A device for preparing a concrete sleeper, characterized in that: Used to prepare a concrete sleeper as described in any one of claims 1 to 5, comprising a first shell (21), a second shell (22), a reaction frame (31), a tension anchor plate (32) and an anchor (33), wherein the first shell (21) is used to form the top surface and side surfaces of the concrete sleeper, and the second shell (22) is used to form the groove (11) of the concrete sleeper, the first shell (21) is a bottom mold, and the second shell (22) is a top mold, and there is a spacing between the top surface of the first shell (21) and the top surface of the second shell (22), and the shape and size of the spacing are adapted to the shape and size of the bottom surface of the concrete sleeper.

7. A preparation device for concrete sleepers according to claim 6, characterized in that: First connecting members (231) are respectively provided on both longitudinal sides of the top surface of the first shell (21), and second connecting members (232) are respectively provided on both longitudinal sides of the top surface of the second shell (22), and the first connecting member (231) and the second connecting member (232) are connected by bolts (24).

8. A method for preparing a concrete sleeper, characterized in that: A preparation device for a concrete sleeper as claimed in any one of claims 1 to 5 or a concrete sleeper as claimed in any one of claims 6 to 7 comprises the following steps: S1, installing a first shell (21), a second shell (22), a prestressing force (12), a reaction frame (31), a tension anchor plate (32) and an anchor (33); S2, tensioning the prestress (12); S3, pouring concrete from the distance between the top surface of the first shell (21) and the top surface of the second shell (22); S4. After curing and forming, the formwork is removed to complete the preparation of concrete sleepers.

9. The method for preparing a concrete sleeper according to claim 8, characterized in that: Before the concrete sleeper is formed, a pre-embedded bracket (14) is also included.

10. A method for installing a concrete sleeper, characterized in that: A concrete sleeper applied to a concrete sleeper as claimed in any one of claims 1 to 5, or a sleeper prepared by a concrete sleeper preparation device as claimed in any one of claims 6 to 7, or a concrete sleeper prepared by a concrete sleeper preparation method as claimed in any one of claims 8 to 9, comprising the following steps: A. Filling the groove (11) of the inverted concrete sleeper with ballast and temporarily closing the opening of the groove (11); B. installing the concrete sleeper at a preset position; C. releasing the temporary closure of the groove (11); D. The concrete sleeper is vibrated to complete the installation of the concrete sleeper.

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