A prestressed road cover support structure

Abstract

The present invention discloses a prestressed pavement cover plate support structure, including a pavement cover plate, a retaining structure and an internal support structure. The retaining structure is a reinforced concrete underground continuous wall symmetrically laid on both sides of a foundation pit. Above the retaining structure is a crown beam, which connects the retaining structure and a first concrete support. The internal support structure includes the first concrete support and a steel support, wherein a plurality of prestressed steel bars are arranged inside the first concrete support, and the pavement cover plate is covered above. The two ends of the first concrete support are firmly connected to the crown beam, and the two ends of the steel support are respectively fixed to the retaining structure on both sides of the foundation pit. In a prestressed pavement cover plate support structure of the present invention, prestressed steel bars are arranged in the first concrete support, which greatly improves the bending strength and bearing capacity of the component, eliminates temporary columns and temporary column piles, reduces the project cost, and improves the construction efficiency and safety.

Description

Technical Field

[0001] The present invention belongs to the field of subway foundation pit construction, and more specifically, relates to a prestressed road surface cover plate supporting structure. Background Art

[0002] Urban subway construction often affects road traffic. In the process of subway station construction, in order to reduce the impact of open-cut construction on traffic, the construction method of cover-cut and follow-up construction is often adopted for the intersection section. That is, first, the retaining structures such as retaining piles or underground continuous walls and vertical temporary supporting columns are completed on the ground surface, and the cast-in-place or prefabricated concrete pavement system is supported by the retaining structures and temporary columns to restore traffic at the road intersection. Then, earthwork is excavated under the cover plate, and the main structure of the underground structure is built from bottom to top, and waterproofing treatment is carried out. After the traffic is relieved, the pavement system and temporary columns are removed. When constructing temporary columns by the cover-cut and follow-up method, the conventional practice is to select more lattice columns as vertical supports for the cover-cut road panel.

[0003] The road cover support structure generally uses the first concrete support of the foundation pit as the main load-bearing beam. Because the foundation pit has a large horizontal span and heavy vehicle load, the first concrete support is subjected to great force. The traditional approach is to set temporary columns and column piles under the concrete support structure to play a supporting role, and change the original horizontal large-span beam into two small-span beams, thereby reducing the stress load of the first concrete support. Figure 1 As shown, the first concrete support is prevented from causing safety accidents due to insufficient bearing capacity. The retaining piles and lattice columns are temporary vertical supports. The cover plate is located above the lattice column. The steel bars of the station top, middle and bottom plates are constructed by bypassing and passing through the middle and both sides of the lattice column. Waterstop steel plates are reserved around the lattice column. After the construction of the station top, middle and bottom plates is completed, the lattice column will be cut off after the cover and excavation system completes the task of traffic relief.

[0004] The disadvantage of this approach is that the rigidity and bearing capacity of the lattice columns are limited, so a large number of them need to be arranged, which affects the operating space and excavation speed of the construction machinery, reduces the construction efficiency, and requires special waterproofing when the lattice columns are removed, which is a complicated process. In addition, the setting process of temporary columns and column piles seriously affects the speed of subway construction, and there are problems such as affecting the installation and decoration of internal equipment of the station before the columns are removed, resulting in low efficiency, waste of consumables costs, and inconvenience in use. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the present invention provides a prestressed pavement cover plate support structure, which includes a pavement cover plate, a retaining structure, and an internal support structure for supporting and holding the pavement cover plate and the retaining structure. The retaining structure is a reinforced concrete underground continuous wall symmetrically laid on the soil layers on both sides of the foundation pit. Above the retaining structure is a crown beam, which is a reinforced concrete continuous beam, and connects the retaining structure and the first concrete support together to effectively prevent the collapse of the foundation pit edge. The internal support structure includes a first concrete support and a steel support, and the first concrete support is covered with the pavement cover plate. The two ends of the first concrete support are firmly connected to the crown beam, the steel support is horizontally arranged and located in the same vertical plane as the first concrete support, and its two ends are respectively fixed to the retaining structure on both sides of the foundation pit, which greatly improves the bending strength and bearing capacity of the first concrete support, thereby eliminating temporary columns and temporary column piles, reducing the project cost and saving costs.

[0006] In order to achieve the above-mentioned object, the present invention provides a prestressed road cover support structure, comprising a road cover, a retaining structure and an internal support structure for supporting the road cover and the retaining structure; wherein:

[0007] The road cover is a concrete slab, and vehicles or pedestrians are directly carried on the top thereof;

[0008] The retaining structure is a reinforced concrete underground continuous wall symmetrically laid on the soil layers on both sides of the foundation pit. Above the retaining structure is a cap beam, which is a reinforced concrete continuous beam and connects the retaining structure and the first concrete support together to effectively prevent the edge of the foundation pit from collapsing.

[0009] The internal support structure includes a first concrete support and a steel support, wherein the road surface cover is covered on the top of the first concrete support, and both ends of the first concrete support are firmly connected to the crown beam. The steel support is arranged horizontally and is located in the same vertical plane as the first concrete support, and its two ends are respectively fixed to the retaining structure on both sides of the foundation pit.

[0010] Furthermore, the first concrete support is a prestressed beam, in which a plurality of prestressed steel bars are arranged to greatly improve the bending strength and bearing capacity of the component.

[0011] Furthermore, the first concrete support and the steel support are both arranged horizontally in space.

[0012] Furthermore, the first concrete support and the steel support are located in the same vertical plane, and are arranged at a certain interval along the direction of the road cover.

[0013] Furthermore, the steel supports are arranged in multiple rows at intervals in the same vertical plane to form a continuous support network.

[0014] Furthermore, the thickness of the road cover is 150 to 450 mm.

[0015] Furthermore, the enclosure structure may be an underground continuous wall or bored cast-in-place piles with a thickness of 0.6 to 1.2 m.

[0016] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0017] (1) A prestressed pavement cover support structure of the present invention includes a pavement cover, a retaining structure, and an internal support structure that supports and holds the pavement cover and the retaining structure. The retaining structure is a reinforced concrete underground continuous wall symmetrically laid on the soil layers on both sides of the foundation pit. Above the retaining structure is a crown beam, which is a reinforced concrete continuous beam, and connects the retaining structure and the first concrete support together, effectively preventing the collapse of the foundation pit edge. The internal support structure includes a first concrete support and a steel support, and the pavement cover is covered above the first concrete support. The first concrete support has two ends firmly connected to the crown beam, the steel support is horizontally arranged and located in the same vertical plane as the first concrete support, and its two ends are respectively fixed to the retaining structure on both sides of the foundation pit, which greatly improves the bending strength and bearing capacity of the first concrete support, thereby eliminating temporary columns and temporary column piles, reducing the project cost and saving costs.

[0018] (2) Compared with the traditional pavement cover plate support structure, the first concrete support of the prestressed pavement cover plate support structure of the present invention is a prestressed prestressed beam, and a plurality of prestressed prestressed steel bars are arranged inside the beam, which greatly improves the bending strength and bearing capacity of the component, reduces the construction time required for building the temporary columns and temporary column piles, facilitates the installation and decoration of equipment inside the station, and greatly improves the construction efficiency and construction safety.

[0019] (3) In a prestressed pavement cover support structure of the present invention, the first concrete support and the steel support are located in the same vertical plane, and are arranged at a certain interval along the direction of the pavement cover, and multiple steel supports are arranged at intervals in the same vertical plane, thereby eliminating temporary columns and temporary column piles. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of a conventional road cover support structure in the prior art;

[0021] Figure 2 This is a schematic diagram of a prestressed pavement cover plate support structure according to an embodiment of the present invention.

[0022] In all the drawings, the same figure numbers represent the same technical features, specifically: 1-first concrete support, 2-pavement cover, 3-temporary column, 4-connecting beam, 5-temporary column pile, 6-enclosing structure, 7-crown beam, 8-steel support, 9-prestressed steel bar. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions 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 intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] like Figure 1 In the schematic diagram of the conventional road cover support structure of the prior art shown, since ordinary concrete beams are used as the first concrete support 1, temporary columns 3 and temporary column piles 5 are added to the support structure. The purpose is to change the original large lateral span into two small spans to reduce the stress load of the first concrete support. However, the construction of the temporary columns 3 and the temporary column piles 5 seriously affects the construction speed, and there are problems such as affecting the installation and decoration of internal equipment of the station before the columns are removed, which is quite inconvenient to use.

[0025] like Figure 2 As shown, a prestressed pavement cover plate support structure according to an embodiment of the present invention includes a pavement cover plate 2, a retaining structure 6 and an internal support structure for supporting the pavement cover plate 2 and the retaining structure 6, wherein the pavement cover plate 2 is a concrete plate with a thickness between 150 and 450 mm, which plays the role of bearing load and resisting impact, and the pavement cover plate 2 directly bears vehicles, pedestrians, etc.

[0026] The retaining structure 6 is a reinforced concrete underground continuous wall, generally with a thickness ranging from 0.6 to 1.2 meters. It is symmetrically cast and laid on the soil layers on both sides of the foundation pit to ensure the stability of the soil on both sides of the foundation pit, control the deformation of the pit wall soil, and ensure that the adjacent buildings around the foundation pit are not damaged during construction; above the retaining structure 6 is a crown beam 2, which is a reinforced concrete continuous beam, and connects the retaining structure 6 and the first concrete support 1 together, effectively preventing the top edge of the foundation pit from collapsing due to the vibration of vehicles on the road and the vibration of large construction tools.

[0027] The internal support structure includes the first concrete support 1 and the steel support 8, wherein the first concrete support 1 covers the road surface cover 2 and bears all the gravity of the road surface cover 2 and the vehicles, pedestrians, etc. above it. The two ends of the first concrete support 1 are firmly connected to the crown beam 2 to transfer the gravity of the road surface cover 2 and the above to the crown beam 2. Due to the large span of the road surface, the first concrete support 1 needs to have extremely high bending strength and load-bearing capacity; the steel support 8 is a top supporting structure, which is arranged in the same vertical plane with the first concrete support 1. The two ends of the steel support 8 are respectively fixed on the retaining structure 6 on both sides of the foundation pit, and multiple steel supports 8 are arranged at intervals in the same vertical plane to ensure the structural stability of the retaining structure 6 during the construction process. The first concrete support 1 and the steel support 8 are arranged once in a vertical plane at intervals of 6 meters along the laying direction of the pavement cover 2, and the gravity of the pavement cover 2 and the area above it is transferred to the first concrete support 1, then to the cap beam 7, and finally to the retaining structure 6 and the steel support 8, thereby forming a continuous support network.

[0028] A prestressed pavement cover support structure of the present invention has a retaining structure that is a reinforced concrete underground continuous wall symmetrically laid on the soil layers on both sides of the foundation pit, and a crown beam is located above the retaining structure. The crown beam is a reinforced concrete continuous beam, and the retaining structure and the first concrete support are connected together to effectively prevent the edge of the foundation pit from collapsing. The internal support structure includes a first concrete support and a steel support, and the first concrete support is covered with the pavement cover. The first concrete support has two ends firmly connected to the crown beam, and the steel support is arranged horizontally and is located in the same vertical plane as the first concrete support. Its two ends are respectively fixed to the retaining structure on both sides of the foundation pit, which greatly improves the bending strength and bearing capacity of the first concrete support, thereby eliminating temporary columns and temporary column piles, reducing the project cost, and saving costs.

[0029] The first concrete support 1 is a prestressed beam, and a plurality of steel bars 9 are arranged inside it. Before pouring concrete, the steel bars 9 are stretched to generate tension. When the concrete reaches no less than 75% of the concrete design strength value and when the steel bars 9 are sufficiently bonded to the concrete, the steel bars 9 are relaxed. By means of the bonding between the concrete and the steel bars 9, prestress is applied to the concrete, thereby improving the bending strength and bearing capacity of the first concrete support 1 and improving the structural safety. Compared with the traditional pavement cover support structure, the first concrete support of the prestressed pavement cover support structure of the present invention is a prestressed beam, and a plurality of prestressed steel bars are arranged inside it, which greatly improves the bending strength and bearing capacity of the component, reduces the construction time required for building the temporary columns and temporary column piles, facilitates the installation and decoration of internal equipment of the station, and greatly improves the construction efficiency and construction safety.

[0030] Compared with the conventional pavement cover plate support structure in the prior art, the prestressed pavement cover plate support structure of the present invention greatly improves the bending strength and bearing capacity of the first concrete support by pre-stressing the first concrete support 1 that bears the pavement cover plate 2 and all the weight above, thereby eliminating the temporary columns 3 and temporary column piles 5, reducing the project cost, saving costs, reducing the construction time required for building the temporary columns 3 and the temporary column piles 5, improving construction efficiency, preventing the temporary columns 3 and the temporary column piles 5 from causing inconvenience to the construction, and improving construction safety.

[0031] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is 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 prestressed pavement cover support structure, characterized in that: It includes a road cover plate, a protective structure, and an internal support structure that supports the road cover plate and the protective structure; wherein: The road cover is a concrete slab, which directly carries vehicles or pedestrians; The retaining structure is a reinforced concrete underground continuous wall symmetrically laid on the soil layers on both sides of the foundation pit. Above the retaining structure is a cap beam, which is a reinforced concrete continuous beam and connects the retaining structure and the first concrete support together to effectively prevent the edge of the foundation pit from collapsing. The internal support structure includes a first concrete support and a steel support, wherein the road cover plate is covered on the first concrete support, and both ends of the first concrete support are firmly connected to the crown beam, and the steel support is arranged horizontally and is located in the same vertical plane as the first concrete support, and both ends of the steel support are respectively fixed to the enclosure structure on both sides of the foundation pit; The first concrete support is a prestressed beam, in which a plurality of prestressed steel bars are arranged to greatly improve the bending strength and bearing capacity of the component; the arrangement process of the prestressed steel bars is as follows: Before pouring concrete, the steel bars are stretched to generate tension. When the concrete reaches a strength not less than 75% of the concrete design strength and sufficient bonding between the prestressed steel bars and the concrete is ensured, the prestressed steel bars are relaxed, and prestress is applied to the concrete by means of bonding between the concrete and the prestressed steel bars. The first concrete support and the steel support are both arranged horizontally in space; the first concrete support and the steel support are located in the same vertical plane, and are arranged one at a certain interval along the direction of the road cover; multiple steel supports are arranged at intervals in the same vertical plane to form a continuous support network; The thickness of the road cover plate is 150-450 mm, and the thickness of the enclosure structure is 0.6-1.2 m.

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