CN106283943A - Elastic roadbed structure - Google Patents

Abstract

An embodiment of the present invention provides an elastic ballast bed structure. It includes: a ballastless monolithic ballast bed made of concrete, the ballastless monolithic ballast bed includes an inverted arch leveling layer and a flat base surface on which sleepers are placed. The concrete includes rubber concrete or flexible concrete or concrete added with other similar materials with high damping ratio and other performance materials. The elastic ballast bed structure proposed by the embodiment of the present invention has the characteristics of environmental protection, low cost, fast construction, good durability and ductility, etc., and is suitable for general use in the whole line. Vibration requirements are reduced, the investment in rail vibration reduction is reduced, and the track stiffness and smoothness of the entire line are ensured to avoid abnormal corrugation of the rail.

Description

Elastic track bed structure

technical field

The invention relates to the technical field of rail transit, in particular to an elastic track bed structure.

Background technique

With the rapid development of rail transit, the impact of environmental vibration has become more and more serious. For example, many lines in Beijing were forced to adjust their line planning due to vibration problems. After the opening of new lines, they faced a large number of vibration complaints. At present, when domestically solving the environmental vibration problems caused by rail transit, ALT.1 fasteners, Vanguard fasteners, shear type shock absorber system fasteners and other fastener vibration reduction measures are usually used; vibration measures; and ballast bed vibration reduction measures such as rubber floating slab track, steel spring floating slab track, trapezoidal track, various ballast bed vibration damping pads, etc. However, relying solely on the above-mentioned rail vibration reduction measures has the following problems:

(1) When the sensitivity to vibration-sensitive targets is high (such as subway lines passing through sensitive buildings at close range or there are scientific research institutions with extremely high vibration requirements along the newly-built subway lines), it is difficult to solve the vibration problem simply by relying on track vibration reduction measures. question. From the perspective of application effect, although a large number of rail vibration reduction measures have been adopted for the new lines of Beijing rail transit, and the proportion of the length of the vibration reduction section on a single line is as high as 64%, the residents and scientific research institutions along the line have concerns about environmental vibration after the line is opened. Complaints are not uncommon, and the main content of the complaints is that the vibration and noise of rail transit disturb the people, the protection of ancient buildings and the normal use of precision instruments are affected.

(2) Track vibration reduction measures mostly use the method of reducing track stiffness. Different track vibration reduction measures for the same line make the stiffness of the entire line uneven, which in turn deteriorates the wheel-rail relationship, leading to the generation and development of rail corrugation. This not only increases the level of environmental vibration, but also lays hidden dangers for the safe operation of rail transit.

Contents of the invention

Embodiments of the present invention provide an elastic ballast bed structure to reduce the impact of track vibration on the surrounding environment.

In order to achieve the above object, the present invention adopts the following technical solutions.

An elastic track bed structure, comprising:

A ballastless monolithic ballast bed made of concrete, the ballastless monolithic ballast bed includes an inverted arch leveling layer and a flat base surface on which sleepers are placed.

Further, the damping ratio of the concrete is higher than a set threshold.

Further, the concrete includes rubber concrete or flexible concrete.

Further, the sleepers include short sleepers, long sleepers or trapezoidal sleepers.

Further, the elastic ballast bed structure is prepared by cast-in-place or prefabricated.

Further, when the elastic ballast bed structure is arranged in a tunnel, the leveling layer of the tunnel invert is paved with the same elastic concrete as that of the ballast bed.

It can be seen from the technical solutions provided by the above-mentioned embodiments of the present invention that the elastic ballast bed structure proposed by the embodiments of the present invention has the characteristics of environmental protection, low cost, fast construction, good durability and ductility, and is suitable for general use in the whole line. The site with particularly strict requirements and other vibration reduction measures can not only meet the environmental vibration requirements and reduce the investment in track vibration reduction, but also ensure the track stiffness and smoothness of the entire line, and avoid abnormal rail corrugation.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and will become apparent from the description, or may be learned by practice of the invention.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

Fig. 1 has provided the schematic diagram of placing short sleepers on the base surface of the elastic ballast bed structure;

Fig. 2 has provided the schematic diagram that long sleeper is placed on the base surface of elastic ballast bed structure;

Fig. 3 has provided the schematic diagram that trapezoidal pillow is placed on the base surface of elastic ballast bed structure;

Fig. 4 has provided the overall effect schematic diagram of placing the elastic ballast bed structure vibration isolation foundation track of the embodiment of the present invention in the shield tunnel;

In the figure, 1-concrete elastic ballast bed; 2-steel rail; 3-short sleeper; 4-long sleeper; 5-trapezoidal sleeper; 6-tunnel.

detailed description

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

Those skilled in the art will understand that unless otherwise stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the word "comprising" used in the description of the present invention refers to the presence of said features, integers, steps, operations, elements and/or components, but does not exclude the presence or addition of one or more other features, Integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Additionally, "connected" or "coupled" as used herein may include wirelessly connected or coupled. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Those skilled in the art can understand that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It should also be understood that terms such as those defined in commonly used dictionaries should be understood to have a meaning consistent with the meaning in the context of the prior art, and will not be interpreted in an idealized or overly formal sense unless defined as herein Explanation.

In order to facilitate the understanding of the embodiments of the present invention, several specific embodiments will be taken as examples for further explanation below in conjunction with the accompanying drawings, and each embodiment does not constitute a limitation to the embodiments of the present invention.

In order to solve the above problems, the research and development of new vibration reduction technology is imperative. According to the theoretical system of rail transit vibration reduction, all measures that can reduce the sensitivity of sensitive targets belong to the category of comprehensive vibration reduction. In addition to reducing the stiffness of the system, vibration reduction can also be performed by increasing the mass of the vibration and dissipating vibration energy.

The rubber concrete material used on airport runways and highway pavements is a semi-rigid concrete material with properties between traditional cement concrete and asphalt concrete. Because rubber mainly improves the internal structure of concrete through physical and mechanical effects, it does not change the chemical properties of various materials in concrete, so it will not damage the durability of concrete. The damping of the material is the main index to measure the vibration-reducing performance of the material itself, and the greater the damping, the stronger the vibration-absorbing ability of the material. Compared with ordinary concrete materials, rubber concrete has higher damping ratio, better impact resistance and ductility, and the elastic modulus and fundamental frequency decrease with the increase of rubber content. When the rubber powder content is between 0.5% and 2.5%, compared with ordinary concrete, the damping ratio can be increased by 50% to 60%; when the rubber powder content exceeds 2.5%, the damping ratio increases with the rubber powder content. And rapid increase, the damping ratio increases by about 1.3 to 2.3 times; when the rubber powder content is about 4.5%, elastic concrete with high damping ratio, elastic modulus and compressive strength can be obtained. Therefore, rubber concrete can be used to reduce vibration and noise.

In addition, rubber concrete has good fire resistance, vibration absorption, impact resistance, burst resistance, heat insulation, sound insulation, etc., and has been widely used in engineering fields. The world's first usable rubber aggregate concrete structure was a section of rubber aggregate concrete sidewalk built on the campus of Arizona State University in the United States in February 1999, and then the state built the world's first waste tire rubber reconstruction in 2003. Road sections with elastic concrete pavement, and road sections with multiple elastic concrete test points. In November 2005, at the entrance of Shijiazhuang, Hebei Province, Qingdao-Yinchuan Expressway, the world's first expressway toll station and service area pavement paved with rubber aggregate concrete were built. In August 2006, rubber aggregate concrete was used as the bridge deck pavement for Erbaihu Dongkou Bridge on Wuxiang Road, Wuqing District, Tianjin. At present, rubber concrete is widely used in the construction of high-grade highways, railway crossing pavement, etc.; and high-strength concrete (concrete with a strength level of C60 or more) mixed with rubber powder has been used in important military buildings, nuclear industry buildings, anti-terrorism Applied to buildings, foundations of mechanical systems, buffer layers of railways and subways, defensive walls, and walls with special requirements for heat and sound insulation.

Therefore, its application prospect in the field of rail transit engineering can be further explored. Rubber can be processed by using waste rubber such as old tires to realize the recycling and pollution-free digestion of waste rubber materials, which has great environmental significance.

Flexible concrete is a modified cement concrete material that incorporates long-fiber polypropylene, steel or glass fibers into the concrete using a special new method. Compared with ordinary cement concrete, flexible concrete is a material with both strength and flexibility. Scholars at home and abroad have adopted many methods to modify cement concrete to reduce its elastic modulus and improve toughness, such as fiber reinforcement, organic polymer materials, high-performance lightweight aggregates, and polymers. In the highway industry, flexible concrete has been put into a large number of applications as a pavement material. It has been widely used because of its good driving comfort, low noise, and strong deformation adaptability. In the field of underground engineering spray support technology, flexible concrete spraying materials with good flexibility and certain tensile and bending properties are used to improve the tensile, bending properties and toughness of the matrix, and there is still a large crack after cracking residual strength. In the field of hydraulic engineering, with the successive construction of large-scale water conservancy projects, flexible concrete is used as the anti-seepage material, because it can guarantee a certain strength with a low elastic modulus and can adapt to large deformation without cracking, and has made great progress. application. In terms of railways, with the high-speed and heavy-duty, the use of viscoelastic flexible concrete as a full-section under-rail foundation material can be expected to play the advantages of waterproof, vibration reduction, noise reduction, adaptation to subgrade deformation, easy maintenance, and environmental protection and recyclability. There have been related research abroad.

The embodiment of the present invention proposes a new type of elastic ballast bed structure, using concrete with a high damping ratio to make a ballastless monolithic ballast bed. The damping ratio of the above-mentioned concrete is higher than a set threshold value. Exemplarily, the threshold value can be: 2%.

Wherein, for example, the concrete may be rubber concrete or flexible concrete.

The embodiments of the present invention increase the elasticity, damping and quality of the ballast bed structure due to the adoption of the concrete elastic ballast bed. According to the principle of vibration reduction, when the vibration wave of the train is transmitted to the ballast bed through the fasteners, the inertia of the ballast bed structure can balance part of the vibration energy. At the same time, the rubber particles or flexible material particles in the ballast bed structure can convert mechanical energy into heat energy, thereby reducing the vibration energy transmitted through the ballast bed structure and achieving the purpose of vibration reduction. Due to the wide range of sources of rubber materials, waste rubber such as old tires can be used for processing to realize the recycling and pollution-free digestion of waste rubber materials, which is of great environmental significance. Therefore, the elastic ballast bed has low cost and is environmentally friendly. In the present invention, the prefabricated energy-absorbing elastic track bed structure has a good damping effect.

The novel elastic ballast bed structure proposed by the embodiments of the present invention reduces vibration by increasing the mass involved in vibration and dissipating vibration energy. The elastic ballast bed structure can be widely used in the whole line, which can better solve the problem of the coexistence of subway vibration reduction and excellent wheel-rail relationship, and avoid or reduce the phenomenon of abnormal rail corrugation. In addition, it can also reduce the vibration impact of the whole line, thereby lowering the vibration reduction level of sensitive sections. The length ratio of the high line, especially the special vibration reduction section, will be greatly reduced. It is very likely that the special vibration reduction length ratio will be controlled at 25%. Within a reasonable ratio range, the vibration reduction investment is greatly reduced.

The embodiment of the elastic ballast bed structure proposed by the embodiment of the present invention is as follows:

After the construction of the tunnel structure is completed, rubber or flexible concrete is used as a leveling layer at the inverted arch of the tunnel, and the construction method is the same as that of ordinary concrete;

Thereafter, according to different construction methods, it can be divided into two methods: prefabricated or cast-in-place for concrete elastic track bed construction.

For the precast concrete elastic track bed, the construction steps are as follows: configure the elastic concrete according to the design ratio of rubber concrete/flexible concrete (the uniformity of rubber particles or other additives in the concrete must be ensured); complete the preparation of the track bed slab in the precast yard , that is, binding steel bars-supporting formwork-fixing support blocks-injecting rubber or flexible concrete-curing-formwork removal; transporting the prefabricated track bed slab to the construction site for laying in place, shear hinge connection between each section of the track bed, rail erection, etc. Work.

For the cast-in-situ concrete elastic track bed, the construction steps are as follows: configure elastic concrete at the concrete preparation site according to the design ratio of rubber concrete/flexible concrete (the uniformity of rubber particles or other additives in the concrete must be ensured), and transport to the construction site On-site: Complete the construction of the track bed slab at the construction site, that is, binding steel bars-supporting formwork-fixing support blocks-filling rubber or flexible concrete-curing-removing formwork-rails and other work.

The elastic ballast bed structure of the embodiment of the present invention uses rubber or flexible concrete to make the ballastless integral ballast bed, which is revolutionary and innovative in the field of rail transportation. During the construction process, the leveling layer of the tunnel inverted arch can also be laid with rubber or flexible concrete to enhance the integrity of the ballast bed structure and the base structure.

Using rubber concrete to make ballastless monolithic ballast bed, the preparation process is almost the same as that of ordinary concrete, only the uniformity of rubber powder/granule mixing should be paid attention to during the preparation process. The elastic ballast bed can be prepared in two ways: cast-in-place or prefabricated.

Those skilled in the art should be able to understand that the above application types of rubber or flexible concrete are only examples, and other existing or future concrete application types, if applicable to the embodiments of the present invention, should also be included within the protection scope of the present invention. and is hereby incorporated by reference.

The elastic ballast bed structure of the embodiment of the present invention can be made into various structural shapes, for example, it can be made into an arc-shaped curved base and a flat base surface, so as to adapt to various foundation types and various tunnel types. Different types of sleepers and fasteners can be placed on the base of the above-mentioned elastic ballast bed structure to meet different vibration reduction requirements. Figure 1 shows a schematic diagram of placing short sleepers on the base of the elastic ballast bed structure, and Figure 2 shows Figure 3 shows a schematic diagram of placing a trapezoidal sleeper on the base of the elastic ballast bed structure.

Fig. 4 shows a schematic diagram of the overall effect of placing the elastic ballast bed structure vibration isolation foundation track of the embodiment of the present invention in the shield tunnel. This kind of track bed can be constructed by prefabrication or cast-in-place two methods.

In summary, the elastic ballast bed structure proposed by the embodiment of the present invention has the characteristics of environmental protection, low cost, fast construction, durability and good ductility, etc., and is suitable for general use on the whole line, and at the same time cooperates with other vibration reduction measures in areas with particularly strict vibration requirements , not only can meet the environmental vibration requirements, reduce the investment in rail vibration reduction, but also ensure the track stiffness and smoothness of the entire line, and avoid the occurrence of abnormal rail corrugation.

Those skilled in the art can understand that the accompanying drawing is only a schematic diagram of an embodiment, and the modules or processes in the accompanying drawing are not necessarily necessary for implementing the present invention.

Those of ordinary skill in the art can understand that: the components in the device in the embodiment can be distributed in the device in the embodiment according to the description in the embodiment, and can also be changed and located in one or more devices different from the embodiment. The components in the above embodiments can be combined into one component, and can also be further divided into multiple subcomponents.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (6)

1. An elastic ballast bed structure, characterized in that it comprises: A ballastless monolithic ballast bed made of concrete, the ballastless monolithic ballast bed includes an inverted arch leveling layer and a flat base surface on which sleepers are placed. 2. The elastic ballast bed structure according to claim 1, wherein the damping ratio of the concrete is higher than a set threshold. 3. The elastic track bed structure according to claim 1, wherein the concrete comprises rubber concrete or flexible concrete. 4. The elastic ballast bed structure according to claim 1, wherein the sleeper comprises a short sleeper, a long sleeper or a trapezoidal sleeper. 5. The elastic ballast bed structure according to claim 1, characterized in that, the elastic ballast bed structure is prepared by cast-in-place or prefabrication. 6. The elastic ballast bed structure according to any one of claims 1 to 5, characterized in that: When the elastic ballast bed structure is arranged in a tunnel, the leveling layer of the tunnel invert is paved with the same elastic concrete as the ballast bed.