阅读说明：本技术 汛期铁路涵洞套顶方法 (Method for sleeving top of railway culvert in flood season ) 是由 焦春海 顾玉峰 梁旭峰 韩春雨 吴俊树 于 2020-07-09 设计创作，主要内容包括：一种汛期铁路涵洞套顶方法。其包括基坑开挖、地基加固、滑板与后背梁施工、首节涵节浇筑、首节涵节顶进、其余涵节原位现筑等步骤。本发明效果：可实现铁路既有涵洞接长施工快速高效、安全施工的目标,保证汛期内的施工顺利安全,减少了施工干扰,降低了施工成本,保证了铁路设备和行车安全,满足了施工进度要求,使涵洞接长不再成为制约工程施工进度的因素。通过工程施工实践证明本施工方法是行之有效的,具有技术可靠、机械化程度高、操作方便、安全可靠、运输效率高、运行成本低、经济效益好的特点,在类似工程施工中有一定借鉴意义和推广价值。(A method for sleeving a culvert on a roof in a flood season railway. The method comprises the steps of foundation pit excavation, foundation stabilization, construction of a sliding plate and a back beam, pouring of a first culvert section, jacking of the first culvert section, in-situ construction of other culvert sections and the like. The invention has the following effects: the method can realize the aims of quick, efficient and safe construction of the existing culvert extension construction of the railway, ensure the smooth and safe construction in the flood season, reduce the construction interference, reduce the construction cost, ensure the railway equipment and the driving safety, meet the construction progress requirement and ensure that the culvert extension does not become a factor restricting the engineering construction progress any more. The construction method is proved to be effective by engineering construction practices, has the characteristics of reliable technology, high degree of mechanization, convenient operation, safety, reliability, high transportation efficiency, low operation cost and good economic benefit, and has certain reference significance and popularization value in similar engineering construction.)

1. A method for jacketing a culvert in a flood season railway is characterized by comprising the following steps: the method for jacketing the culvert in the flood season railway comprises the following steps of:

1) when the existing culvert (1) needs to be lengthened, firstly, excavating a foundation pit at the position where a new culvert is to be arranged in a manner of manually matching with an excavator; when the foundation pit is excavated, a plurality of sliding plate anchor beam foundation pits are transversely excavated on the bottom surface of the foundation pit along the foundation pit by adopting a mechanical and manual matching mode; the new culvert is composed of a plurality of culvert sections which are connected end to end, wherein the culvert section (2) at the first section close to the existing culvert (1) is constructed by adopting a jacking method, and the other culvert sections (3) are constructed by adopting an in-situ cast-in-place method.

2) Forming a plurality of high-pressure jet grouting piles at intervals in the foundation below the new culvert by using high jet grouting pile equipment so as to reinforce the foundation;

3) arranging a layer of sliding plate with a reinforced concrete structure on the bottom surface of the foundation pit, and manufacturing an anchor beam in the sliding plate anchor beam foundation pit to increase the anti-skidding capacity; then constructing a back beam of a reinforced concrete structure at the rear end of the sliding plate, and connecting the steel bars on the sliding plate and the steel bars on the back beam with each other, thereby connecting the back beam and the sliding plate into a whole; then, arranging a plurality of guide piers at positions 30cm away from the new culvert to be poured on two sides of the sliding plate along the jacking direction so as to prevent possible direction deviation of the new culvert in the empty-top stage;

4) laying a layer of plastic cloth on the surface of the sliding plate, then binding a reinforcing steel bar frame of the first culvert section (2) on the plastic cloth, erecting a template, pouring concrete in the template, and preparing the first culvert section (2) with the aperture smaller than that of the existing culvert (1) after the concrete is solidified and reaches the designed strength;

5) a plurality of jacks are arranged between the back beam and the rear end of the bottom plate of the first culvert section (2), then the jacks are started to empty the first culvert section (2) in the direction of the existing culvert (1), and jacking is stopped until the distance between the front end of the first culvert section (2) and the rear end of the existing culvert (1) is 1 meter; chiseling a bottom plate 1m at the rear part of the existing culvert (1), starting the jack again to jack the first culvert section (2) for 1m towards the existing culvert (1), chiseling 1m, then jacking for 1m, repeating the steps until the front end of the first culvert section (2) enters the inner part 5m at the rear part of the existing culvert (1), and stopping jacking; when the first culvert section (2) is jacked to 1m inside the existing culvert (1), drilling is carried out on the side wall of the existing bottom plate by adopting a water drill to separate the bottom plate from the side wall, a drill core is not taken out after drilling is finished, and the bottom plate is completely chiseled by manually matching a breaking hammer every 1m of jacking so as to ensure that the jacking range is smooth and unimpeded;

6) after the first culvert section (2) is jacked in place, the gaps between the wing walls of the existing culvert (1) and the jacked side walls are poured and backfilled tightly by concrete so as to ensure the stability of the existing wing walls;

7) and constructing the other culvert sections (3) in the foundation pit at the rear side of the first culvert section (2) by adopting an in-situ cast-in-situ method, thereby completing the lengthening construction process of the existing culvert (1).

2. The flood season railway culvert jacking method according to claim 1, characterized in that: in the step 1), the foundation pit excavation adopts a 1:1 slope-releasing mode, and a working surface of 1.1m is reserved on the outer side of the main body of the existing culvert 1.

3. The flood season railway culvert jacking method according to claim 1, characterized in that: in the step 2), the pile diameter of the high-pressure jet grouting pile is 0.6m, the pile length is 7.5m, the distance is 1m, and the high-pressure jet grouting pile is arranged in a regular triangle.

4. The flood season railway culvert jacking method according to claim 1, characterized in that: in the step 3), the thickness of the sliding plate is 35 cm; the back beam consists of an M10 grouted rubble back and a distribution beam; the surface of the sliding plate is leveled by M10 mortar, the thickness is not more than 2cm, and engine oil and stone powder with the thickness of 1-2mm are coated on the surface.

Technical Field

The invention belongs to the technical field of railway culvert construction, and particularly relates to a method for sleeving a top of a railway culvert in a flood season.

Background

According to the stipulations of the construction specifications of railway bridge and culvert engineering, the railway culvert is divided according to the structural form and the construction type, wherein the railway culvert can be divided into a frame culvert, a cover plate culvert and a round pipe culvert according to the structural form, and can be divided into a newly-built culvert, an extended culvert and a jacking culvert according to the construction type. If the culvert is lengthened and the construction method and the construction date of the culvert are limited to a certain extent, the construction safety risk level can be correspondingly improved. Therefore, the scientific and reasonable construction method is selected, the construction operation safety is ensured, the construction can be quickly and effectively organized, the construction task can be completed according to the schedule, and the method is the difficulty of the construction of the existing lengthened culvert.

According to the requirements of site conditions, construction work amount and contract construction period, the culvert lengthening construction usually adopts the following methods:

1. in-situ casting: and (3) constructing a roadbed guard pile and a crown beam before the culvert is lengthened, excavating a foundation pit and reinforcing a foundation after the wing wall is chiseled off, and finally casting the culvert in situ and connecting the culvert with the existing culvert. The advantages are that: high speed, high efficiency and short construction period. The disadvantages are as follows: the stability of the existing railway equipment can be affected by the need of arranging manual dug piles and chiseling wing walls. The manual hole digging pile must be arranged on the existing roadbed side slope, has high requirements on the existing roadbed filling type and underground water, is easy to collapse, and is restricted by flood season.

2. Prefabricating and assembling: firstly prefabricating culvert sections outside a field and maintaining, constructing roadbed protecting piles and crown beams when the culvert is lengthened, excavating foundation pits and reinforcing the foundation after chiseling wing walls, and finally hoisting the prefabricated culvert sections, splicing and connecting the prefabricated culvert sections with the existing culvert. The advantages are that: the culvert sections are prefabricated in advance, so that the maintenance time is saved, and the culvert sections are poured once, so that the templates are saved. The disadvantages are as follows: the culvert sections are prefabricated, the occupied area is large, the investment cost is high, and the seams are easy to be untight and leak water when the culvert sections are assembled, so that the service life of the culvert is influenced. The construction of the manual hole digging pile influences the stability of the existing railway equipment and is restricted by flood season.

Disclosure of Invention

In order to solve the problems, the invention aims to provide a method for sleeving a culvert on a roof in a flood season railway.

In order to achieve the purpose, the method for jacketing the culvert in the flood season railway comprises the following steps of:

1) when the existing culvert needs to be lengthened, firstly, a foundation pit is excavated at the position where a new culvert is to be arranged in a manner of manually matching with an excavator; when the foundation pit is excavated, a plurality of sliding plate anchor beam foundation pits are transversely excavated on the bottom surface of the foundation pit along the foundation pit by adopting a mechanical and manual matching mode; the new culvert is composed of a plurality of culvert sections which are connected end to end, wherein the culvert section which is close to the existing culvert is constructed by adopting a jacking method, and the other culvert sections are constructed by adopting an in-situ cast-in-place method;

2) forming a plurality of high-pressure jet grouting piles at intervals in the foundation below the new culvert by using high jet grouting pile equipment so as to reinforce the foundation;

3) arranging a layer of sliding plate with a reinforced concrete structure on the bottom surface of the foundation pit, and manufacturing an anchor beam in the sliding plate anchor beam foundation pit to increase the anti-skidding capacity; then constructing a back beam of a reinforced concrete structure at the rear end of the sliding plate, and connecting the steel bars on the sliding plate and the steel bars on the back beam with each other, thereby connecting the back beam and the sliding plate into a whole; then, arranging a plurality of guide piers at positions 30cm away from the new culvert to be poured on two sides of the sliding plate along the jacking direction so as to prevent possible direction deviation of the new culvert in the empty-top stage;

4) laying a layer of plastic cloth on the surface of the sliding plate, then binding a reinforcing steel bar frame of a first culvert section on the plastic cloth, erecting a template, pouring concrete in the template, and preparing the first culvert section with the aperture smaller than that of the existing culvert after the concrete is solidified and reaches the designed strength;

5) a plurality of jacks are arranged between the back beam and the rear end of the bottom plate of the first culvert section, then the jacks are started to empty the first culvert section towards the existing culvert, and jacking is stopped until the distance between the front end of the first culvert section and the rear end of the existing culvert is 1 meter; chiseling a bottom plate 1m at the rear part of the existing culvert, starting the jack again to jack the first culvert section for 1m towards the existing culvert, chiseling 1m, then jacking for 1m, repeating the steps until the front end of the first culvert section enters the inner part 5m at the rear part of the existing culvert, and stopping jacking; when the first culvert section is jacked to 1m in the existing culvert, drilling is carried out on the side wall of the existing bottom plate by adopting a water drill to separate the bottom plate from the side wall, the drill core is not taken out after drilling is finished, and the bottom plate is completely chiseled by manually matching a breaking hammer every 1m of jacking so as to ensure that the jacking range is smooth and unimpeded;

6) after the first culvert section is jacked in place, the gaps between the wing walls of the existing culvert and the jacked side walls are poured and backfilled tightly by concrete so as to ensure the stability of the existing wing walls;

7) and constructing the other culvert sections in the foundation pit at the rear side of the first culvert section by adopting an in-situ cast-in-situ method, thereby completing the lengthening construction process of the existing culvert.

The foundation pit excavation adopts a 1:1 slope-releasing mode, and a working surface of 1.1m is reserved on the outer side of the existing culvert body.

In the step 2), the pile diameter of the high-pressure jet grouting pile is 0.6m, the pile length is 7.5m, the distance is 1m, and the high-pressure jet grouting pile is arranged in a regular triangle.

In the step 3), the thickness of the sliding plate is 35 cm; the back beam consists of an M10 grouted rubble back and a distribution beam; the surface of the sliding plate is leveled by M10 mortar, the thickness is not more than 2cm, and engine oil and stone powder with the thickness of 1-2mm are coated on the surface.

The method for sleeving the top of the culvert in the flood season has the following beneficial effects:

the method can realize the aims of quick, efficient and safe construction of the existing culvert extension construction of the railway, ensure the smooth and safe construction in the flood season, reduce the construction interference, reduce the construction cost, ensure the railway equipment and the driving safety, meet the construction progress requirement and ensure that the culvert extension does not become a factor restricting the engineering construction progress any more. The construction method is proved to be effective by engineering construction practices, has the characteristics of reliable technology, high degree of mechanization, convenient operation, safety, reliability, high transportation efficiency, low operation cost and good economic benefit, and has certain reference significance and popularization value in similar engineering construction.

Drawings

FIG. 1 is a side view of the construction process of the culvert jacking method for the flood season railway.

FIG. 2 is a top view of the construction process of the flood season railway culvert jacking method provided by the invention.

Detailed Description

The existing plate culvert in a railway special line project is a drainage culvert, a culvert needing to be newly lengthened is a 1-5m frame culvert, the length of the culvert is 23.06m, the culvert is divided into 4 culvert sections, wherein the length of the culvert section close to the first section of the existing plate culvert is 9.0m, the jacking method is adopted for construction, the jacking distance is 10.3m, and the rest 3 culvert sections are constructed by an in-situ cast-in-place method. The net height of the culvert is 4.45m, the excavation depth of the foundation pit is 2.27m, the wall thickness of the culvert body is 0.5m, the bottom plate thickness of the culvert is 0.6m, and the top plate thickness is 0.55m, according to the requirement of the construction period, the construction needs to be completed in the flood season, the construction difficulty is large, the safety risk is high, and the construction is a major difficult point control project.

The invention is described in detail below with reference to the figures and specific embodiments.

As shown in fig. 1-2, the method for jacketing a culvert in a flood season railway comprises the following steps in sequence:

1) when the existing culvert 1 needs to be lengthened, firstly, excavating a foundation pit at the position where a new culvert is to be arranged in a manner of manually matching with an excavator; when the foundation pit is excavated, a plurality of sliding plate anchor beam foundation pits are transversely excavated on the bottom surface of the foundation pit along the foundation pit by adopting a mechanical and manual matching mode; in the invention, the foundation pit excavation adopts a 1:1 slope-releasing mode, a working surface of 1.1m is reserved on the outer side of the main body of the existing culvert 1, the length of the foundation pit is 19.98m, the width of the foundation pit is 12.74m, and the depth of the foundation pit is 2.27 m; the new culvert consists of a plurality of culvert sections which are connected end to end, wherein the culvert section 2 at the first section close to the existing culvert 1 is constructed by adopting a jacking method, and the other culvert sections 3 are constructed by adopting an in-situ cast-in-place method;

2) forming a plurality of high-pressure jet grouting piles at intervals in the foundation below the new culvert by using high jet grouting pile equipment so as to reinforce the foundation; in the invention, the pile diameter of the high-pressure jet grouting pile is 0.6m, the pile length is 7.5m, the distance is 1m, and the high-pressure jet grouting pile is arranged in a regular triangle.

3) Arranging a layer of sliding plate with a reinforced concrete structure on the bottom surface of the foundation pit, and manufacturing an anchor beam in the sliding plate anchor beam foundation pit to increase the anti-skidding capacity; then constructing a back beam of a reinforced concrete structure at the rear end of the sliding plate, and connecting the steel bars on the sliding plate and the steel bars on the back beam with each other, thereby connecting the back beam and the sliding plate into a whole; then, arranging a plurality of guide piers at positions 30cm away from the new culvert to be poured on two sides of the sliding plate along the jacking direction so as to prevent possible direction deviation of the new culvert in the empty-top stage; in the invention, the thickness of the sliding plate is 35 cm; the back beam consists of an M10 grouted rubble back and a distribution beam. In order to prevent the sliding plate from being adhered to the bottom plate of the new culvert and reduce the starting resistance, the surface of the sliding plate is smoothed by M10 mortar, the thickness is not more than 2cm, the flatness is required to be optimal, and then engine oil and stone powder with the thickness of 1-2mm are coated on the sliding plate, the surface is required to be smooth and clean, so that the jacking friction resistance is reduced;

4) laying a layer of plastic cloth on the surface of the sliding plate, effectively isolating the sliding plate from the bottom plate of the new culvert when pouring to prevent the bottom plate from being stuck together and avoid the difficulty in jacking, then binding the reinforcing steel bar frame of the first culvert section 2 on the plastic cloth, erecting a template, pouring concrete in the template, and preparing the first culvert section 2 with the aperture smaller than that of the existing culvert 1 after the concrete is solidified and reaches the design strength;

5) a plurality of jacks are arranged between the back beam and the rear end of the bottom plate of the first culvert section 2, then the jacks are started to empty the first culvert section 2 in the direction of the existing culvert 1, and jacking is stopped until the distance between the front end of the first culvert section 2 and the rear end of the existing culvert 1 is 1 meter; chiseling a bottom plate 1m at the rear part of the existing culvert 1, starting the jack again to jack the first culvert section 2 into the existing culvert 1 for 1m, chiseling 1m, then jacking for 1m, repeating the steps until the front end of the first culvert section 2 enters the inner part 5m at the rear part of the existing culvert 1, and stopping jacking; when the first culvert section 2 is jacked to 1m in the existing culvert 1, drilling is carried out on the side wall of the existing bottom plate to separate the bottom plate from the side wall, a drill core is not taken out after drilling is finished, and the bottom plate is completely chiseled by manually matching a breaking hammer every 1m of jacking so as to ensure that the jacking range is smooth and unimpeded;

6) after the first culvert section 2 is jacked in place, the wing walls of the existing culvert 1 and the gaps of the jacked side walls are filled and backfilled tightly by concrete so as to ensure the stability of the existing wing walls.

7) And constructing the other culvert sections 3 in the foundation pit at the rear side of the first culvert section 2 by adopting an in-situ cast-in-situ method, thereby completing the lengthening construction process of the existing culvert 1.