Pile-slab structure roadbed for tram and construction method thereof

Abstract

The present application relates to the field of urban rail transit engineering, and in particular to a pile-slab roadbed for trams and a construction method thereof. The pile-slab roadbed comprises a pile body, a cushion layer, and a raft slab. The pile body is buried in the roadbed soil, the cushion layer is laid on the pile body, and the raft slab is laid on the cushion layer. The raft slab is used to lay the tracks for trams. The pile-slab roadbed does not require a subgrade layer, and the tracks are laid directly on the raft slab, which greatly reduces the thickness of the roadbed structure, reduces earth excavation, reduces tedious construction processes, and reduces construction costs.

Description

Technical Field

[0001] The present application relates to urban rail transit projects, and in particular to a pile-slab structure roadbed for trams and a construction method thereof. Background Art

[0002] Modern trams are a convenient, economical, and effective new green public transportation system. With low project investment, a short construction period, promising development prospects, and widespread application, they have attracted the attention of many cities and become a popular mode of transportation. However, there are currently no unified standards for trams in China, and road subgrade structures vary widely, with thick subgrades requiring extensive excavation, complex construction processes, and poor economic efficiency. Summary of the Invention

[0003] In view of this, an embodiment of the present application provides a pile-plate structure roadbed for a tram and a construction method thereof to solve the problem of a thick roadbed.

[0004] To achieve the above objectives, the technical solution of the embodiment of the present application is implemented as follows:

[0005] In one aspect, an embodiment of the present application provides a pile-plate structure roadbed for a tram, comprising:

[0006] Pile body, buried in the roadbed soil;

[0007] a cushion layer, laid on the pile body; and

[0008] A raft slab is laid on the cushion layer, and the raft slab is used for laying tracks for trams.

[0009] In some embodiments, the thickness of the raft is 270 mm to 330 mm; and / or the thickness of the cushion layer is 90 mm to 110 mm.

[0010] In some embodiments, the raft is provided with connecting ribs for laying the track, and the connecting ribs are provided at the upper end of the raft.

[0011] In some embodiments, when the distance between the two tracks is less than or equal to 4 m, the two raft plates at the lower ends of the two tracks are integrally formed; or

[0012] When the line spacing between the two tracks is greater than 4m, the two raft plates at the lower ends of the two tracks are respectively formed and spaced apart.

[0013] In some embodiments, the plurality of piles are arranged at intervals along the length direction of the track and the width direction of the track.

[0014] In some embodiments, the cross section of the pile body is circular, and the outer diameter of the pile body is 400 mm to 600 mm; and / or the spacing between the pile bodies is 3 to 5 times the outer diameter of the pile body.

[0015] In some embodiments, the depth at which the lower end of the pile penetrates the bearing layer of the roadbed soil is greater than or equal to 1 m.

[0016] In some embodiments, the raft is a reinforced concrete plate structure, the cushion is a concrete structure, and the pile is a plain concrete structure;

[0017] The concrete strength of the raft slab is greater than the concrete strength of the pile body, and the concrete strength of the pile body is greater than the concrete strength of the cushion layer.

[0018] Another aspect of the present application provides a method for constructing a pile-plate structure roadbed for a tram, comprising:

[0019] Leveling the site and conducting stakeout measurements to determine the pre-installed location of the piles;

[0020] Conducting a pile construction test on the pile body and a load test on a single pile body;

[0021] Drilling holes at the pre-installed location and pouring concrete to form the pile body;

[0022] After the pile body strength reaches the requirement, a cushion layer is laid on the top of the pile body;

[0023] A raft slab for laying tracks is poured on the upper end of the cushion layer.

[0024] In some embodiments, the step of drilling a hole at the pre-installed location and pouring concrete to form the pile body specifically includes: drilling the hole using a long spiral drilling method.

[0025] The present invention provides a pile-slab roadbed for trams, comprising a pile body, a cushion layer, and a raft slab. The pile-slab roadbed does not require a subgrade layer; the tracks are laid directly on the raft slab, significantly reducing the thickness of the roadbed structure, excavation, and complex construction processes, thereby lowering construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structure of a pile-plate structure roadbed for a tram in one embodiment of the present application, wherein the raft structure is a separated structure;

[0027] Figure 2 Schematic diagram of the structure of a pile-plate structure roadbed for a tram in one embodiment of the present application, wherein the raft structure is an integral structure;

[0028] Figure 3 A schematic diagram of the structure of a pile-sheet structure roadbed for a tram in accordance with an embodiment of the present application, wherein the elevation of the track is higher than the ground line; and

[0029] Figure 4 Schematic diagram of a construction method of a pile-plate structure roadbed for a tram according to an embodiment of the present application.

[0030] Description of reference numerals:

[0031] Pile body 1; cushion layer 2; raft slab 3; connecting reinforcement 31; track 4; bearing layer 5; ground line 6; excavation line 7; sloping line 8; pipeline trough 9. DETAILED DESCRIPTION

[0032] It should be noted that the various embodiments / implementations provided in this application can be combined with each other without causing any contradiction. The detailed description in the specific implementation manner should be understood as an explanation of the purpose of this application and should not be regarded as an improper limitation on this application.

[0033] In the description of this application, the terms "upper" and "lower" are used to refer to the position or location of the device. Figure 1 The orientation or position relationship shown in the figure, the term "width direction" orientation or position relationship is based on the attached Figure 1 The orientation or positional relationship shown. The term "longitudinal direction" refers to the direction along the track line. It should be understood that these directional terms are merely for the purpose of facilitating the description of this application and simplifying the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting this application.

[0034] One aspect of the present application provides a pile-plate structure roadbed for a tram, see Figure 1 As shown, the pile-sheet roadbed structure includes a pile body 1, a cushion layer 2, and a raft 3. The pile body 1 is buried in the roadbed soil, the cushion layer 2 is laid on the pile body 1, and the raft 3 is laid on the cushion layer 2. The raft 3 is used to lay the track 4 of the tram.

[0035] Modern trams typically use a monolithic roadbed. The roadbed consists of a surface layer and a subgrade layer, with the subgrade structure typically being 1 meter thick. The track requirements for modern trams differ from those for railways and subways, and the typical railway roadbed structure is not well suited to the needs of modern trams.

[0036] Because it falls within the municipal sector, construction excavation requirements are high. Furthermore, since there is no unified standard for roadbed structures, the use of traditional monolithic roadbeds results in thicker roadbeds, resulting in extensive excavation, complex construction processes, and poor economic efficiency. For foundation treatment in areas with deep, soft soil, composite foundation treatment methods such as cement-soil mixing piles and cement-fly-ash gravel piles are generally used. While these methods can effectively control settlement, they are less reliable than pile-board foundations in controlling deformation, settlement, and overall stability.

[0037] The present application provides a pile-slab roadbed for trams. On the one hand, the track 4 is laid directly on the raft slab 3 without requiring a subgrade layer, significantly reducing the thickness of the roadbed structure, excavation, and complex construction processes, thereby lowering construction costs. On the other hand, the pile-slab roadbed fully utilizes the interaction between the pile soil between the pile bodies 1 and the slab soil between the raft slabs 3 to meet the strength and settlement deformation requirements of ballastless track in deep, soft soil areas, achieving a smooth transition between bridges and tunnels and providing a highly reliable foundation treatment measure.

[0038] In one embodiment, when the line elevation is lower than the ground line 6, Figure 1 and Figure 2 The method shown is to construct the pile-sheet structure roadbed along the excavation line 7. When the line elevation is higher than the ground line 6, Figure 3 The method shown is to construct the pile-sheet structure roadbed along the grading line 8.

[0039] In one embodiment, see Figure 1 , the thickness of the raft 3 is 270mm to 330mm; and / or, the thickness of the cushion layer 2 is 90mm to 110mm. That is to say, the thickness of the raft 3 can be between 270mm and 330mm, and can be 270mm, 290mm, or 330mm. The thickness of the cushion layer 2 can be between 90mm and 110mm, and can be 90mm, 105mm, or 110mm. Exemplarily, in one embodiment, the thickness of the raft 3 is 300mm, and the thickness of the cushion layer 2 is 100mm, so as to ensure that the raft 3 and the cushion layer 2 have a certain structural strength while reducing the cost of the raft 3 and the cushion layer 2.

[0040] In one embodiment, see Figure 1 The raft 3 is provided with connecting ribs 31 for laying the track 4. The connecting ribs 31 are located at the upper end of the raft 3. The connecting ribs 31 can be provided in any manner. Exemplary connection methods include, but are not limited to, pre-embedded or planted. Since the track 4 is laid directly on the upper end of the raft 3, the provision of the connecting ribs 31 facilitates the positioning and laying of the track 4 on the raft 3.

[0041] In one embodiment, see Figures 1 to 3Pipeline grooves 9 can also be set on both sides of the upper end of the raft 3 along the width direction of the track 4 according to actual conditions to facilitate the maintenance of the line pipeline.

[0042] In one embodiment, see Figures 1 to 3 When the line spacing d between the two tracks 4 is less than or equal to 4m, the two rafts 3 at the lower ends of the two tracks 4 are constructed as an integral part; or, when the line spacing d between the two tracks 4 is greater than 4m, the two rafts 3 at the lower ends of the two tracks 4 are formed separately and spaced apart. That is to say, different raft 3 structures are set according to the width of the line spacing d of the tracks 4. When the line spacing d between the tracks 4 is less than or equal to 4m, the raft 3 structure is an integral structure. When the line spacing d between the tracks 4 is not large, the raft 3 with an integral structure has high strength and a compact structure. The raft 3 can be cast in one piece, and the construction process is simpler. When the line spacing d between the tracks 4 is greater than or equal to 4m, the raft 3 structure is a separate structure. When the line spacing d between the tracks 4 is large, the raft 3 with a separate structure has a lower cost, which can reduce the overall construction cost.

[0043] In one embodiment, see Figure 1 and Figure 2 , multiple pile bodies 1 are arranged at intervals along the length direction of the track 4 and the width direction of the track 4. On the one hand, by arranging multiple pile bodies 1 at intervals, the load transferred by the raft 3 can be evenly distributed on the multiple pile bodies 1, and the stability of the roadbed is better. On the other hand, multiple pile bodies 1 are arranged along the length direction and the width direction of the track 4, so that the pile body 1 structure forms a multi-row pile structure. This structure has greater bending stiffness and can withstand greater horizontal loads. It should be noted that the above-mentioned multiple pile bodies 1 refer to two or more pile bodies 1.

[0044] There is no limitation on the spacing distribution of the pile bodies 1. For example, it may be arranged in a matrix (square arrangement, rectangular arrangement) or a plum blossom arrangement.

[0045] In one embodiment, see Figure 1 and Figure 2 , the cross-section of the pile body 1 is circular, and the outer diameter of the pile body 1 is 400mm to 600mm; and / or, the spacing between the pile bodies 1 is 3 to 5 times the outer diameter of the pile body 1. That is to say, the outer diameter of the pile body 1 can be between 400mm and 600mm, and can be 400mm, 550mm, or 600mm. And the spacing between the pile bodies 1 can be between 1.2m and 3m, and can be 1.2m, 1.8m, 2.4m, or 3m. Exemplarily, in one embodiment, the diameter of the pile body 1 is 500mm, and the spacing between the pile bodies 1 is 1.8m. This ensures that the multiple pile bodies 1 have good bearing capacity and the force on each pile body 1 is more uniform.

[0046] In one embodiment, see Figure 1 and Figure 2 The depth of the lower end of the pile body 1 penetrating the bearing layer 5 of the roadbed soil is greater than or equal to 1 meter. In other words, the lower end of the pile body 1 should be buried at a depth of at least 1 meter in the bearing layer 5 of the roadbed soil. In this way, the load borne by multiple pile bodies 1 can be effectively and dispersedly transmitted to the bearing layer 5.

[0047] In one embodiment, see Figure 1 and Figure 2 The raft 3 is a reinforced concrete slab structure, the cushion layer 2 is a concrete structure, and the pile body 1 is a plain concrete structure. The concrete strength of the raft 3 is greater than that of the pile body 1, and the concrete strength of the pile body 1 is greater than that of the cushion layer 2. For example, in one embodiment, since the raft 3 directly bears the roadbed load and needs to have a relatively high structural strength, the raft 3 uses a C35 reinforced concrete slab to directly bear the roadbed load. At the same time, the internal reinforcement of the raft 3 should meet the design load requirements. The cushion layer 2 uses C15 concrete. The cushion layer 2 can level the raft 3 structure during construction, while protecting the isolated bottom reinforcement from soil contamination and facilitating construction layout and foundation formwork support. The pile body 1 is responsible for transferring the load and uses C30 plain concrete. When multiple pile bodies 1 are combined to form a pile foundation, the pile foundation has a high bearing capacity. At the same time, the plain concrete pile construction equipment is simple, easy to operate, saves steel, and is highly economical.

[0048] Another aspect of the present application provides a method for constructing a pile-plate structure roadbed for a tram. Figure 4 , the construction method includes the following steps:

[0049] S1. Level the site and conduct stakeout measurements to determine the pre-installed location of the piles.

[0050] S2. Conduct a pile construction test on the pile body and a load test on a single pile body;

[0051] S3. Drill holes at the pre-installed location and pour concrete to form piles;

[0052] S4. After the pile strength reaches the required level, a cushion layer is laid on top of the pile;

[0053] S5. Cast the raft slab for laying the track on the upper end of the cushion layer.

[0054] The following is a detailed description of each step of the construction method of the pile-plate structure roadbed of the tram in the embodiment of the present application.

[0055] S1. Level the site and carry out stakeout measurement of the pile position to determine the pre-installation position of the pile.

[0056] See also Figure 4As shown, the site is leveled and the position of the pile body 1 is measured to determine the pre-installed position of the pile body 1. After the measurement, the position of each pile body 1 and the distance between the pile bodies 1 can be accurately calibrated, and the calibrated position is the pre-installed position of the pile body 1.

[0057] S2. Carry out pile construction test on the pile body and load test on a single pile body.

[0058] See also Figure 4 As shown, pile driving tests can provide firsthand information on construction parameters such as effective pile length, rock penetration depth, sediment, penetration rate, and bearing capacity before construction. This allows for the selection of physical parameters of the pile, such as pile type, size, and length. This allows for the selection of appropriate pile driver equipment, reducing construction costs and improving safety.

[0059] It is understandable that step S2 may be performed before step S1 or after step S1, or step S1 and step S2 may be performed simultaneously.

[0060] S3. Drill holes at the pre-installed location and pour concrete to form piles.

[0061] See also Figure 4 As shown, a hole is drilled and concrete is poured according to actual conditions to form the pile body 1. If necessary, a guard arm may be applied to stabilize the hole wall during drilling to prevent collapse. The pile body 1 may be drilled using any method, including but not limited to percussion drilling, forward and reverse circulation drilling, and spiral drilling. Different drilling methods may be used according to actual conditions.

[0062] For example, in one embodiment, the pile body 1 is drilled using a long spiral drilling method. This method is dry drilling, produces no mud, and reduces construction noise and vibration. It is suitable for piles of various diameters and can be used on various foundations, including stand-alone foundations, strip foundations, and raft foundations, offering high versatility.

[0063] S4. After the pile strength reaches the requirement, lay a cushion layer on the top of the pile.

[0064] See also Figure 4 As shown, the cushion layer 2 can play a leveling role for the construction of the raft 3 structure, while isolating the bottom reinforcement from being contaminated by the soil, and can facilitate construction layout and support of foundation templates.

[0065] S5. Cast the raft slab for laying the track on the upper end of the cushion layer.

[0066] See also Figure 4As shown, the raft 3 is cast. Since the raft 3 directly bears the roadbed load, it needs to have a large structural strength to directly bear the roadbed load. At the same time, the raft 3 should be reinforced to meet the design load requirements. Connecting reinforcement 31 can be provided at the upper end of the raft 3 to facilitate the positioning and laying of the track 4 on the raft 3. Subsequently, the track 4 is directly laid on the raft 3 according to the track laying requirements.

[0067] In one embodiment, see Figure 1 As shown, the raft slab 3 is constructed of C35 reinforced concrete with a thickness of 300mm. The reinforcement of the raft slab 3 is determined by mechanical analysis and structural requirements. Connecting bars 31 for the track 4 are reserved on the raft slab 3. The cushion layer 2 is constructed of C15 concrete with a thickness of 100mm. The piles are constructed of C30 cable concrete with a diameter of 500mm and a spacing of 1.8m. Long auger drilling and pouring are used. As a result, the thickness of the pile-slab roadbed structure is only 400mm, significantly reducing the roadbed structure thickness, thereby reducing earthwork excavation and improving project economics. This has high application prospects.

[0068] The above description is merely a specific embodiment of the present application, but the scope of protection of this application is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A pile-slab structure roadbed for trams, characterized in that: include: Multiple piles are buried in the roadbed soil, each pile having a circular cross-section and an outer diameter of 400 mm to 600 mm. The multiple piles are spaced apart along the length and width of the track, and the spacing between the piles is 3 to 5 times the outer diameter of the pile. A cushion layer is laid on the pile body, and the thickness of the cushion layer is 90 mm to 110 mm; as well as A raft slab is laid on the cushion layer, the raft slab is used for laying tram tracks, the raft slab is provided with connecting ribs for laying the tracks, the connecting ribs are arranged at the upper end of the raft slab, the thickness of the raft slab is 270 mm to 330 mm, the raft slab is a reinforced concrete plate structure, the cushion layer is a concrete structure, the pile body is a plain concrete structure, the concrete strength of the raft slab is greater than the concrete strength of the pile body, and the concrete strength of the pile body is greater than the concrete strength of the cushion layer.

2. The pile-sheet structure roadbed according to claim 1, characterized in that: When the distance between the two tracks is less than or equal to 4m, the two raft plates at the lower ends of the two tracks are integrally formed; or When the line spacing between the two tracks is greater than 4m, the two raft plates at the lower ends of the two tracks are respectively formed and spaced apart.

3. The pile-sheet structure roadbed according to claim 1, characterized in that: The depth at which the lower end of the pile body penetrates into the bearing layer of the roadbed soil is greater than or equal to 1m.

4. A construction method for a pile-plate structure roadbed for a tram, characterized in that: The method is used to manufacture the pile-plate structure roadbed of a tram according to any one of claims 1 to 3, and the method comprises: Leveling the site and performing stakeout measurement of the pile positions to determine the pre-installation positions of the piles, wherein the spacing between the piles is calibrated, and the calibrated positions are the pre-installation positions of the piles; Conducting a pile construction test on the pile body and a load test on a single pile body; Drilling holes at the pre-installed location and pouring concrete to form the pile body; After the pile body strength reaches the requirement, a cushion layer is laid on the top of the pile body; pouring a raft slab for laying tracks on the upper end of the cushion layer; Connecting ribs are arranged on the upper end of the raft slab.

5. The construction method according to claim 4, characterized in that: The step of drilling holes and pouring concrete at the prefabricated location to form the pile body specifically includes: drilling holes by using a long spiral drilling method.

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