A new type of bridge spanning structure between mountain tunnels and its construction method

Abstract

The present invention is applicable to the field of bridge engineering, and provides a new type of bridge spanning structure and construction method between mountain tunnels. The bridge spanning structure includes a bridge main beam, abutment wing walls, a buffer layer, and a cement crushed stone stabilized fill. The bridge main beam is consolidated with the top of the abutment wing wall to form a portal-type rigid frame bridge. The bridge spanning structure of the present invention improves the economy and durability of the bridge structure throughout its life cycle by adopting a portal-type rigid frame bridge. At the same time, the structure realizes a hidden drainage function, which prevents backflow in the tunnel and improves driving safety. At the same time, the construction method provided by the present invention has little disturbance to the tunnel mountain during construction, little impact on driving safety on the existing road over which the bridge crosses, a short construction period, and high efficiency.

Description

Technical Field

[0001] The invention belongs to the field of bridge engineering, and in particular relates to a new type of bridge spanning structure between tunnels in mountainous areas and a construction method thereof. Background Art

[0002] Due to the complex terrain, mountain roads often encounter situations where two tunnel exits that are close to each other need to cross the existing road below. When the span is small, considering factors such as economic applicability, bridges or channel culverts are usually used for crossing. Traditional construction methods include cast-in-place, prefabricated hoisting, etc. However, traditional construction methods have a series of problems such as large disturbance to the tunnel mountain, great impact on the traffic of existing roads, poor structural durability, and high maintenance costs. In order to reduce the disturbance to the tunnel mountain and the impact on the traffic of existing roads, improve the durability of the structure, and consider the economic efficiency of maintenance throughout the life cycle, it is necessary to propose a new type of bridge spanning structure and construction method between mountain tunnels. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a new type of bridge spanning structure between mountain tunnels and its construction method, aiming to solve the problems in the prior art that the traditional spanning method has a great disturbance to the tunnel mountain, a great impact on the traffic of existing roads, poor durability, and poor economic efficiency of maintenance throughout the life cycle.

[0004] The present invention is implemented as follows: a new type of bridge span structure between mountain tunnels includes a bridge main beam, abutment wing walls, a buffer layer and a cement crushed stone stabilized filling body; the bridge main beam adopts a prestressed concrete precast beam, and the bridge main beam is consolidated with the top of the abutment wing wall to form a portal-type rigid frame bridge; the buffer layer is located on the back of the abutment wing wall, and the cement crushed stone stabilized filling body is located on the back of the buffer layer, and a water intercepting ditch is arranged on the top of the buffer layer, and the water intercepting ditch extends along the longitudinal direction of the bridge main beam; the bottom of the buffer layer and the cement crushed stone stabilized filling body is provided with a drainage ditch, and the drainage ditch is used to collect drainage that flows into the buffer layer from the top.

[0005] Furthermore, the prestressed concrete precast beam may be a precast small box beam, a precast T beam or other new prestressed concrete box beam structures.

[0006] Furthermore, the main beam of the bridge includes a plurality of prestressed concrete precast beams, and the plurality of prestressed concrete precast beams are rigidly connected transversely by on-site post-cast concrete.

[0007] Furthermore, the buffer layer is arranged within 3m behind the abutment wing wall. The buffer layer is composed of sandy soil and non-woven geotextile and is used to absorb the longitudinal secondary internal force of the rigid frame.

[0008] Furthermore, a vertical reinforcing steel wire mesh is provided in the buffer layer outside the range of 1 m from the abutment wing wall.

[0009] Furthermore, the cross-section of the cement gravel stabilized filling body is in the shape of an inverted trapezoid.

[0010] Furthermore, abutment rigid cross beams are provided on both sides of the top surface of the abutment wing wall, the prestressed concrete precast beams are embedded between the two abutment rigid cross beams, and concrete wet joints are provided between adjacent prestressed concrete precast beams.

[0011] In order to solve the above technical problems, the present invention also provides a construction method of the above bridge span structure, comprising the following steps:

[0012] S1. Construct the cement gravel stabilized filling body beyond 3m behind the abutment wing wall;

[0013] S2, constructing the abutment wing wall;

[0014] S3, constructing a 3m wide buffer layer between the abutment wing wall and the cement gravel stabilized fill and a water intercepting ditch on the top of the buffer layer;

[0015] S4. Erect the bridge girders, cast on-site the concrete wet joints between the bridge girders and the rigid cross beams between the main bridge and the abutments.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The new type of bridge span structure between mountain tunnels provided by the present invention improves the economy and durability of the bridge structure throughout its life cycle by adopting a portal-type rigid frame bridge. The main beam of the bridge is erected on-site in the form of prestressed concrete precast beams, and a hidden drainage function is realized to prevent backflow into the tunnel, thereby improving driving safety. The bridge span structure has good economy and durability in terms of maintenance throughout its life cycle. At the same time, the construction method provided by the present invention has little disturbance to the tunnel mountain, little impact on driving on the existing road over which the bridge crosses, short construction period, and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a cross-sectional schematic diagram of a new type of bridge spanning structure between mountain tunnels provided by an embodiment of the present invention;

[0019] Figure 2 yes Figure 1 A schematic plan view of the bridge spanning structure shown;

[0020] Figure 3 yes Figure 1 Schematic diagram of the connection location between the bridge girder and the abutment wing wall of the bridge span structure shown. DETAILED DESCRIPTION

[0021] 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 intended to limit the present invention.

[0022] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention; the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be a connection between the two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] See also Figure 1 and Figure 2 , showing a preferred embodiment provided by the present invention, a new type of bridge span structure between mountain tunnels, including a bridge main beam 1, abutment wing walls 2, a buffer layer 3 and a cement gravel stabilized filling body 4.

[0024] The main bridge beam 1 adopts a prestressed concrete precast beam 11. In this embodiment, the prestressed concrete precast beam 11 is a precast small box beam, a precast T beam or other new prestressed concrete box beam structure, which can be selected comprehensively based on factors such as span and project cost.

[0025] The bridge main beam 1 comprises a plurality of prestressed concrete precast beams 11, and the plurality of prestressed concrete precast beams 11 are rigidly connected transversely through on-site post-cast concrete wet joints.

[0026] The main beam 1 of the bridge is consolidated with the top of the abutment wing wall 2 to form a portal-type rigid frame bridge. By adopting the portal-type rigid frame bridge, the economy and durability of the bridge structure over its entire life cycle are improved, and the impact on driving safety on existing roads is small.

[0027] See also Figure 3Abutment rigid cross beams 5 are provided on both sides of the top surface of the abutment wing wall 2, a prestressed concrete precast beam 11 is embedded between the two abutment rigid cross beams 5, and a concrete wet joint 6 is provided between adjacent prestressed concrete precast beams 11.

[0028] A buffer layer is set within 3m behind the abutment wing wall 2. The buffer layer 3 is composed of sandy soil and non-woven geotextile to absorb the internal force of the rigid frame. A vertical reinforcing steel wire mesh is set in the buffer layer 3 outside the range of 1m from the abutment wing wall.

[0029] The cement crushed stone stabilized filling body 4 is located at the back of the buffer layer 3 to ensure the stability of the backfill. Optionally, the cement crushed stone stabilized filling body 4 has an inverted trapezoidal cross-section.

[0030] A drainage ditch 7 is provided at the bottom of the buffer layer 3 and the cement crushed stone stabilized filling body 4. The drainage ditch 7 is used to collect drainage that flows into the buffer layer 3 and the cement crushed stone stabilized filling body 4 from the top.

[0031] A 1-meter-wide intercepting ditch 8 is provided on the top of the buffer layer 3. The intercepting ditch 8 extends along the longitudinal direction of the bridge main beam 1. The intercepting ditch 8 can guide the accumulated water on the bridge deck into the drainage ditch on the bridge deck and then into the buffer layer 3, and finally into the drainage ditch 7 system on the ground to prevent it from backflowing into the tunnel and causing hidden dangers to driving safety.

[0032] This embodiment also provides a construction method for the above bridge span structure, comprising the following steps:

[0033] S1, cement crushed stone stabilized fill 4 outside the 3m range behind the construction abutment wing wall 2;

[0034] S2, construction of abutment wing wall 2;

[0035] S3, a 3m wide buffer layer 3 between the construction abutment wing wall 2 and the cement gravel stabilized fill 4 and a water intercepting ditch 8 on the top of the buffer layer 3;

[0036] S4, erecting the bridge main beams 1, and casting on site the concrete wet joints 6 between the bridge main beams 1 and the abutment rigid cross beams 5 between the main bridge and the abutments.

[0037] It can be seen that the bridge span structure of this embodiment improves the economy and durability of the bridge structure throughout its life cycle by adopting the portal rigid frame bridge method. It also realizes the hidden drainage function, prevents backflow in the tunnel, and improves driving safety. The bridge span structure has good economy and durability in its life cycle.

[0038] At the same time, the construction method of the bridge span structure has little disturbance to the tunnel mountain, little impact on driving on existing roads, short construction period and high efficiency.

[0039] 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 new type of bridge spanning structure between mountain tunnels, characterized in that: It includes a bridge main beam, abutment wing walls, a buffer layer and a cement gravel stabilized filling body; the bridge main beam adopts a prestressed concrete precast beam, and the bridge main beam is consolidated with the top of the abutment wing wall to form a portal-type rigid frame bridge; the buffer layer is located on the back of the abutment wing wall, and the cement gravel stabilized filling body is located on the back of the buffer layer, and a water intercepting ditch is arranged on the top of the buffer layer, and the water intercepting ditch extends along the longitudinal direction of the bridge main beam; the bottom of the buffer layer and the cement gravel stabilized filling body is provided with a drainage ditch, and the drainage ditch is used to collect drainage flowing into the buffer layer from the top; the prestressed concrete precast beam adopts a prefabricated small box beam, a prefabricated T beam or a prestressed concrete box beam structure; the bridge main beam includes a plurality of prestressed concrete precast beams, and the plurality of prestressed concrete precast beams are rigidly connected transversely through on-site post-cast concrete transverse wet joints to form an integrated rigid crossbeam.

2. The bridge spanning structure according to claim 1, characterized in that: The buffer layer is arranged within 3m behind the abutment wing wall. The buffer layer is composed of sandy soil and non-woven geotextile and is used to absorb the longitudinal secondary internal force of the rigid frame.

3. The bridge spanning structure according to claim 2, characterized in that: A vertical reinforcing steel wire mesh is arranged in the buffer layer outside the range of 1 m from the abutment wing wall.

4. The bridge spanning structure according to claim 1, characterized in that: The cross-section of the cement crushed stone stable filling body is in the shape of an inverted trapezoid.

5. The bridge spanning structure according to claim 1, characterized in that: Abutment rigid cross beams are arranged on both sides of the top surface of the abutment wing wall, the prestressed concrete precast beams are embedded between the two abutment rigid cross beams, and concrete wet joints are arranged between adjacent prestressed concrete precast beams.

6. A construction method for a bridge spanning structure as claimed in claim 5, characterized in that: The following steps are involved: S1. Construct the cement gravel stabilized filling body beyond 3m behind the abutment wing wall; S2, constructing the abutment wing wall; S3, constructing a 3m wide buffer layer between the abutment wing wall and the cement gravel stabilized fill and a water intercepting ditch on the top of the buffer layer; S4. Erect the bridge girders, cast on-site the concrete wet joints between the bridge girders and the rigid cross beams between the main bridge and the abutments.

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