Construction method of existing track structure protection frame

Abstract

The invention relates to a construction method for a protection frame of an existing track structure, which is used for providing a base surface for construction of a newly-added structure above the existing track structure and forming the protection frame on the outer side of the existing track structure in cooperation with existing support piles. The protection frame construction method comprises the following steps that S1, cast-in-situ bored pile construction is conducted; s2, earth excavation is conducted; s3, upper pile bodies of the existing support piles and the cast-in-situ bored piles are cut off; the cast-in-situ bored piles and the structural pile foundations are constructed to be matched with the existing supporting piles to increase the overall supporting strength, the deformation resistance of the foundations on the two sides of the existing track structure is improved in cooperation with earthwork reinforcement, and meanwhile the existing supporting piles, the cast-in-situ bored piles and the structural pile foundations form an overall frame structure by constructing the top beams and the straining beams; when the newly-added structure above the existing track structure is constructed, a construction base plane of the newly-added structure is provided, and meanwhile the problem that due to the fact that loads of the newly-added structure are directly loaded to the position above the existing track structure, lateral deformation of the existing track structure is serious is solved.

Description

Technical Field

[0001] The invention relates to the technical field of engineering construction, and in particular to a construction method for an existing track structure protection frame. Background Art

[0002] With the continuous development of economy, society and construction technology, underground rail transit has developed more and more rapidly. New buildings may be built on top of existing track structures, thereby increasing the additional load on top of the track structure. This part of the load is difficult to predict during the construction of the track structure, and the track structure has extremely stringent requirements on deformation. Therefore, a construction method for a protection frame of an existing track structure is designed. When a new structure is added above the existing track structure, an upper structure construction base is formed, and the lower track structure is protected. Summary of the invention

[0003] The purpose of the present invention is to overcome the defects of the prior art and provide a method for constructing a protective frame for an existing track structure, so as to solve the problem in the prior art that a newly constructed structure directly above the existing track structure will add a large load to the existing track structure, resulting in serious lateral deformation of the existing track structure.

[0004] To achieve the above object, the present invention provides a method for constructing a protection frame of an existing track structure, which is used to provide a base surface for constructing a new structure above the existing track structure, and cooperate with existing support piles to form a protection frame outside the existing track structure; the protection frame construction method comprises the following steps:

[0005] S1. Construction of bored piles;

[0006] S2, earth excavation;

[0007] S3. The upper part of the existing supporting piles and bored piles shall be cut off;

[0008] S4. Earthwork reinforcement between existing support piles and bored cast-in-place piles;

[0009] S5. Construction of structural pile foundation;

[0010] S6. Construction of crown beam and tension beam.

[0011] By adopting this technical solution, bored cast-in-place piles and structural pile foundations are constructed in coordination with the existing supporting piles to increase the overall supporting strength, and combined with earth reinforcement to increase the deformation resistance of the foundations on both sides of the existing track structure. At the same time, through the construction of cap beams and tension beams, the existing supporting piles, bored cast-in-place piles and structural pile foundations form an overall frame structure. When a new structure is constructed above the existing track structure, a construction base surface for the new structure is provided, while avoiding the problem of direct loading of the new structure load onto the existing track structure, which would cause serious lateral deformation of the existing track structure.

[0012] Furthermore, the step S1 includes defining a construction scope on the existing track structure according to the newly added structural design drawings, and constructing bored cast-in-place piles outside the existing support piles within the construction scope.

[0013] By adopting this technical solution, demarcating the construction scope can reduce the amount of construction work without affecting normal construction, thereby reducing manpower, material and time costs.

[0014] Furthermore, the step S2 includes excavating the earth within the construction scope defined in step S1 until the excavation reaches the top elevation of the existing track structure.

[0015] By adopting this technical solution and taking the top elevation of the existing track structure as the benchmark, construction errors can be effectively reduced.

[0016] Furthermore, the step S3 includes cutting off the pile bodies of the existing supporting piles and bored piles that exceed the top elevation of the existing track structure.

[0017] By adopting this technical solution, it is possible to avoid the influence of the existing supporting piles and bored cast-in-place piles exceeding the top elevation of the existing track structure on the subsequent construction.

[0018] Furthermore, step S4 includes reinforcing the earth between the existing supporting piles and the bored piles by constructing high-pressure jet grouting piles in the soil layer between the existing supporting piles and the bored piles or by grouting in the soil layer between the existing supporting piles and the bored piles.

[0019] By adopting this technical solution, after the soil layer between the existing supporting piles and bored piles is reinforced, the supporting piles and bored piles can be used to further improve the bearing capacity of the foundation on both sides of the existing track structure, preventing the lateral stress caused by severe deformation of the foundation on both sides from causing deformation of the existing track structure.

[0020] Furthermore, the step S5 includes constructing a structural pile foundation in the reinforced soil layer between the existing support piles and the bored piles.

[0021] By adopting this technical solution, the structural pile foundation serves as the foundation pile for the subsequent newly added structure. At the same time, it cooperates with bored cast-in-place piles and support piles to improve the support strength and increase the anti-deformation ability of the existing track structure.

[0022] Furthermore, the step S5 also includes cleaning the debris between the piles after the construction of the structural pile foundation is completed.

[0023] By adopting this technical solution, the debris can be prevented from affecting subsequent construction.

[0024] Further, the step S6 includes tying a first crown beam steel bar on the top of the existing support pile, tying a second crown beam steel bar on the top of the bored pile, tying a tension beam steel bar between the first crown beam steel bar and the second crown beam steel bar and between the first crown beam steel bars on both sides of the corresponding existing track structure, and connecting the tension beam steel bar to the first crown beam steel bar and the second crown beam steel bar respectively;

[0025] A formwork is set up outside the first crown beam reinforcement, the second crown beam reinforcement and the tension beam reinforcement after being tied;

[0026] Concrete is poured onto the first crown beam reinforcement, the second crown beam reinforcement and the tension beam reinforcement until the concrete is consolidated to complete the construction of the crown beam and the tension beam.

[0027] By adopting this technical solution, the construction efficiency is increased by using the method of synchronous construction of the crown beam and the tension beam, and at the same time the connection strength of the crown beam and the tension beam is increased, thereby ensuring the stability of the construction base of the new structure.

[0028] Furthermore, the step S6 before pouring concrete also includes setting a reinforcement plate between the tension beam steel bars and between the first crown beam steel bars and the second crown beam steel bars, and the steel bars in the reinforcement plate pass through the tension beam steel bars and connect the tension beam steel bars into a whole.

[0029] By adopting this technical solution, the reinforced tension plate acts as a cushion layer, while increasing the integrity of the steel structure and the subsequent cast-in-place structure, thereby increasing the structural strength.

[0030] Furthermore, after the construction of the structural pile foundation in step S5 is completed, the top surface height thereof is greater than the top elevation of the existing track structure.

[0031] By adopting this technical solution, the structural pile foundation is integrated with the cap beam and the tension beam after their construction, thereby increasing the structural strength of the formed frame.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The bored cast-in-place piles and structural pile foundations are constructed in coordination with the existing supporting piles to increase the overall supporting strength, and are coordinated with earthwork reinforcement to increase the deformation resistance of the foundations on both sides of the existing track structure. At the same time, the existing supporting piles, bored cast-in-place piles and structural pile foundations are formed into an integral frame structure through the construction of cap beams and tension beams. When a new structure is constructed above the existing track structure, a construction base surface for the new structure is provided, while avoiding the problem of direct loading of the new structure load onto the existing track structure, which would cause serious lateral deformation of the existing track structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of step S1 of the construction method of the existing track structure protection frame in the present invention;

[0035] Figure 2 It is a schematic diagram of steps S2-S3 of the construction method of the existing track structure protection frame in the present invention;

[0036] Figure 3 It is a schematic diagram of step S4 of the construction method of the existing track structure protection frame in the present invention;

[0037] Figure 4 It is a schematic diagram of step S5 of the construction method of the existing track structure protection frame in the present invention;

[0038] Figure 5 It is a schematic diagram of step S6 of the construction method of the existing track structure protection frame in the present invention;

[0039] Figure 6 It is a schematic diagram of the flow of the construction method of the existing track structure protection frame in the present invention.

[0040] Explanation of the reference numerals in the accompanying drawings: 1. existing track structure; 2. existing supporting piles; 3. soil layer; 4. bored cast-in-place piles; 5. first crown beam reinforcement; 6. second crown beam reinforcement; 7. structural pile foundation; 8. tension beam reinforcement; 9. tension beam reinforcement. DETAILED DESCRIPTION

[0041] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0042] Embodiment 1:

[0043] Please refer to the attached Figure 1-6 The present invention provides a method for constructing a protection frame of an existing track structure, which is used to provide a base surface for constructing a new structure above the existing track structure, and cooperate with the existing support piles 2 to form a protection frame outside the existing track structure 1; the protection frame construction method includes the following steps:

[0044] S1. Delimit the construction scope on the existing track structure 1 according to the newly added structural design drawings, and construct bored cast-in-place piles 4 outside the existing support piles 2 within the construction scope;

[0045] S2, excavating the earthwork within the construction scope defined in step S1 until the excavation reaches the top elevation of the existing track structure 1;

[0046] S3, cutting off the pile bodies of the existing supporting piles 2 and bored piles 4 that exceed the top elevation of the existing track structure 1;

[0047] S4, the soil between the existing support piles 2 and the bored piles 4 is reinforced by constructing high-pressure jet grouting piles in the soil layer 3 between the existing support piles 2 and the bored piles 4;

[0048] S5, constructing a structural pile foundation 7 in the reinforced soil layer 3 between the existing supporting piles 2 and the bored cast-in-place piles 4, and cleaning the debris between the piles after the construction of the structural pile foundation 7 is completed;

[0049] S6. Tie the first crown beam steel bar 5 on the top of the existing supporting pile 2, tie the second crown beam steel bar 6 on the top of the bored cast-in-place pile 4, tie the tension beam steel bar 8 between the first crown beam steel bar 5 and the second crown beam steel bar 6 and between the first crown beam steel bars 5 on both sides of the corresponding existing track structure 1, and connect the tension beam steel bar 8 to the first crown beam steel bar 5 and the second crown beam steel bar 6 respectively; set a reinforcement plate between the tension beam steel bars 8 and between the first crown beam steel bars 5 and the second crown beam steel bars 6, the steel bars in the reinforcement plate pass through the tension beam steel bars 8 and connect the tension beam steel bars 8 into a whole; support the formwork outside the tied first crown beam steel bars 5, the second crown beam steel bars 6, the tension beam steel bars 8 and the reinforcement plate; pour concrete on the first crown beam steel bars 5, the second crown beam steel bars 6 and the tension beam steel bars 8 until the concrete is consolidated to complete the construction of the crown beam and the tension beam.

[0050] Embodiment 2:

[0051] Please refer to the attached Figure 1-6 The present invention provides a method for constructing a protection frame of an existing track structure, which is used to provide a base surface for constructing a new structure above the existing track structure, and cooperate with the existing support piles 2 to form a protection frame outside the existing track structure 1; the protection frame construction method includes the following steps:

[0052] S1. Delimit the construction scope on the existing track structure 1 according to the newly added structural design drawings, and construct bored cast-in-place piles 4 outside the existing support piles 2 within the construction scope;

[0053] S2, excavating the earthwork within the construction scope defined in step S1 until the excavation reaches the top elevation of the existing track structure 1;

[0054] S3, cutting off the pile bodies of the existing supporting piles 2 and bored piles 4 that exceed the top elevation of the existing track structure 1;

[0055] S4, reinforcing the earth between the existing support piles 2 and the bored cast-in-place piles 4 by grouting in the soil layer 3 between the existing support piles 2 and the bored cast-in-place piles 4;

[0056] S5, constructing a structural pile foundation 7 in the reinforced soil layer 3 between the existing supporting piles 2 and the bored cast-in-place piles 4, and cleaning the debris between the piles after the construction of the structural pile foundation 7 is completed;

[0057] S6. Tie the first crown beam steel bar 5 on the top of the existing supporting pile 2, tie the second crown beam steel bar 6 on the top of the bored cast-in-place pile 4, tie the tension beam steel bar 8 between the first crown beam steel bar 5 and the second crown beam steel bar 6 and between the first crown beam steel bars 5 on both sides of the corresponding existing track structure 1, and connect the tension beam steel bar 8 to the first crown beam steel bar 5 and the second crown beam steel bar 6 respectively; set a reinforcement plate between the tension beam steel bars 8 and between the first crown beam steel bars 5 and the second crown beam steel bars 6, the steel bars in the reinforcement plate pass through the tension beam steel bars 8 and connect the tension beam steel bars 8 into a whole; support the formwork outside the tied first crown beam steel bars 5, the second crown beam steel bars 6, the tension beam steel bars 8 and the reinforcement plate; pour concrete on the first crown beam steel bars 5, the second crown beam steel bars 6 and the tension beam steel bars 8 until the concrete is consolidated to complete the construction of the crown beam and the tension beam.

[0058] The present invention is described in detail above in conjunction with the embodiments of the accompanying drawings. A person skilled in the art can make various variations of the present invention according to the above description. Therefore, certain details in the embodiments should not constitute a limitation of the present invention, and the scope of protection of the present invention shall be defined by the scope of the attached claims.

Claims

1. A method for constructing a protective frame for an existing track structure, which is used to provide a base surface for constructing a new structure above the existing track structure, and cooperate with existing support piles to form a protective frame outside the existing track structure; characterized in that: The protection frame construction method comprises the following steps: S1. Construction of bored piles; S2, earth excavation; S3. The upper part of the existing supporting piles and bored piles shall be cut off; S4. Earthwork reinforcement between existing support piles and bored cast-in-place piles; S5. Construction of structural pile foundation; S6. Construction of crown beam and tension beam.

2. The method for constructing a protection frame for an existing track structure according to claim 1, characterized in that: The step S1 includes defining a construction scope on the existing track structure according to the newly added structural design drawings, and constructing bored cast-in-place piles outside the existing support piles within the construction scope.

3. The method for constructing a protection frame for an existing track structure according to claim 2, characterized in that: The step S2 includes excavating the earth within the construction scope defined in step S1 until the excavation reaches the top elevation of the existing track structure.

4. The method for constructing a protection frame for an existing track structure according to claim 3, characterized in that: The step S3 includes cutting off the pile bodies of the existing supporting piles and bored piles that exceed the top elevation of the existing track structure.

5. The method for constructing a protection frame for an existing track structure according to claim 4, characterized in that: The step S4 includes reinforcing the earth between the existing supporting piles and the bored piles by constructing high-pressure jet grouting piles in the soil layer between the existing supporting piles and the bored piles or by grouting in the soil layer between the existing supporting piles and the bored piles.

6. The method for constructing a protection frame for an existing track structure according to claim 5, characterized in that: The step S5 includes constructing a structural pile foundation in the reinforced soil layer between the existing support piles and the bored piles.

7. The method for constructing a protection frame for an existing track structure according to claim 6, characterized in that: The step S5 also includes cleaning the debris between the piles after the construction of the structural pile foundation is completed.

8. The method for constructing a protection frame for an existing track structure according to claim 6, characterized in that: The step S6 includes tying a first crown beam steel bar on the top of the existing support pile, tying a second crown beam steel bar on the top of the bored pile, tying a tension beam steel bar between the first crown beam steel bar and the second crown beam steel bar and between the first crown beam steel bars on both sides of the corresponding existing track structure, and connecting the tension beam steel bar to the first crown beam steel bar and the second crown beam steel bar respectively; A formwork is set up outside the first crown beam reinforcement, the second crown beam reinforcement and the tension beam reinforcement after being tied; Concrete is poured onto the first crown beam reinforcement, the second crown beam reinforcement and the tension beam reinforcement until the concrete is consolidated to complete the construction of the crown beam and the tension beam.

9. The method for constructing a protection frame for an existing track structure according to claim 6, characterized in that: The step S6 also includes setting a reinforcement plate between the tension beam steel bars and between the first crown beam steel bars and the second crown beam steel bars before pouring concrete, wherein the steel bars in the reinforcement plate pass through the tension beam steel bars and connect the tension beam steel bars into a whole.

10. The method for constructing a protection frame for an existing track structure according to claim 6, characterized in that: After the construction of the structural pile foundation in step S5 is completed, the top surface height thereof is greater than the top elevation of the existing track structure.

Images