CONSTRUCTION METHOD FOR OVERHEAD JACKING OF MULTI-TRACK EXISTING RAILWAY OF FRAME BRIDGE

Abstract

Disclosed is a construction method for overhead jacking of a multi-track existing railway of a frame bridge. By means of construction modes of transition overhead construction-dewatering construction-formal overhead and two-end opposite jacking and middle cast-in-place, the risk caused by the groundwater level to a dig-hole pile is directly avoided. The overall construction scheme for the overpass pipe section follows the principle of segmented construction and line production, a jacking part of the overpass is firstly constructed, and after the jacking part is in place, a middle frame is cast in place, which guarantees not only the railway operation but also the construction period quality, and thus good economic benefits and construction guidance significance are achieved.

Claims

1. A construction method for overhead jacking of a multi-track existing railway of a frame bridge, comprising the specific steps as follows: one, excavating working foundation on both sides of the multi-track existing railway; two, prefabricating jacking pipe sections in the working foundation pits; three, performing transition overhead; four, dewatering by a broached groove; five, performing hole digging construction for a formal overhead pile; six, after the step five is completed, jacking, by a jack, the prefabricated jacking pipe sections into an overhead system from both sides of the multi-track existing railway in a direction perpendicular to the existing railway; seven, performing overhead conversion in a mode of pile breaking while jacking, after the jacking pipe sections on both sides of the multi-track existing railway are jacked in place, replacing an overhead pile with the jacking pipe sections to serve as a supporting structure, and forming a construction space of a middle cast-in-place pipe section by erecting a horizontal lifting beam; and then casting a pipe section in place between the jacking pipe sections; and eight, after the pipe section is cast in place, regarding that the construction of the frame bridge underpass multi-track existing railway is completed, dismounting overhead equipment to recover the normal operation of the railway.

2. The construction method for overhead jacking of multi-track existing railway of a frame bridge according to claim 1, wherein in the step one and step two, a side wall of the working foundation pit is provided with formwork concrete.

3. The construction method for overhead jacking of multi-track existing railway of a frame bridge according to claim 1, wherein the specific method of transition overhead in the step three is as follows: digging a pile hole below the existing railway according to the load design, with a hole digging depth above groundwater level; then casting a temporary overhead pile, and erecting an upper overhead component by taking the pile top of the temporary overhead pile as a fulcrum.

4. The construction method for overhead jacking of multi-track existing railway of a frame bridge according to claim 3, wherein the upper overhead component comprises longitudinal beams and steel sleepers.

5. The construction method for overhead jacking of multi-track existing railway of a frame bridge according to claim 1, wherein the specific method in the step four is as follows: after the transition overhead in the step three is completed, constructing working grooves below the existing railway and between the temporary overhead piles in each row, constructing foundation pit fender piles and dewatering wells by using working faces in the working grooves, and then performing dewatering to enable the ground water level to reach the designed water level.

6. The construction method for overhead jacking of multi-track existing railway of a frame bridge according to claim 5, wherein in the step four, the dewatering wells are distributed at both sides of the multi-track existing railway and in the working grooves; the dewatering wells are mechanically constructed.

7. The construction method for overhead jacking of multi-track existing railway of a frame bridge according to claim 1, wherein the specific method in the step five is as follows: digging a pile hole, underneath the temporary overhead pile, below the existing railway according to the load design, with a hole digging depth below the groundwater level, and then casting the formal overhead pile, and arranging a horizontal lifting beam in a penetrating manner with the pile top of the formal overhead pile as a fulcrum so as to form an overhead system.

8. The construction method for overhead jacking of multi-track existing railway of a frame bridge according to claim 7, wherein the formal overhead pile is constructed by a manual hole digging method.

9. The construction method for overhead jacking of multi-track existing railway of a frame bridge according to claim 1, wherein in the step seven, the jacking pipe section and the cast-in-place pipe section each comprise a pipe section roof, a pipe section baseplate, pipe section side walls and a pipe section middle partition wall; the pipe section roof is in contact with an upper load, the pipe section baseplate is in contact with the ground, the pipe section side walls and the pipe section middle partition wall are connected to the pipe section roof and the pipe section baseplate, and the pipe section middle partition wall is located between the pipe section side walls and is parallel to the pipe section side walls.

10. The construction method for overhead jacking of multi-track existing railway of a frame bridge according to claim 9, wherein one side of the pipe section baseplate of the jacking pipe section is provided with a triangular correction block, such that the jacking pipe section and the existing railway are constructed in a skew jacking manner.

Description

DRAWINGS

[0028] FIG. 1 is a schematic diagram of a plane structure in accordance with the present disclosure;

[0029] FIG. 2 is a schematic diagram of a cross-sectional structure in accordance with the present disclosure;

[0030] FIG. 3 is a sectional diagram of a broached groove in accordance with the present disclosure;

[0031] FIG. 4 is a schematic diagram of a longitudinal section structure in accordance with the present disclosure; and

[0032] FIG. 5 is a schematic diagram of jacking construction of a pipe section of a frame bridge in accordance with the present disclosure,

[0033] In the drawings: 1—jacking pipe section; 2—cast-in-place pipe section; 3—temporary overhead pile; 4—working groove; 5—foundation pit fender pile; 6—formal overhead pile; 7—longitudinal beam; 8—steel sleeper; 9—horizontal lifting beam; 10—working foundation pit; 11, triangular correction block; 12—dewatering well; 13—back wall; 14—jack; 15—working baseplate; 1-1—pipe section roof; 1-2—pipe section baseplate; 1-3—pipe section side wall; 1-4—pipe joint middle partition wall.

DETAILED DESCRIPTION

[0034] The following clearly and completely describes the technical solutions in the present disclosure with reference to the accompanying drawings. Apparently, the described embodiments are merely a part rather than all of the embodiments of the present disclosure. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

[0035] The following clearly and completely describes the technical solutions in the present disclosure with reference to the accompanying drawings. Apparently, the described embodiments are merely a part rather than all of the embodiments of the present disclosure. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

[0036] Referring to FIG. 1 to FIG. 5, a construction method for overhead jacking of a multi-track existing railway of a frame bridge, which comprises the following specific steps:

[0037] A construction method for overhead jacking of a multi-track existing railway of a frame bridge comprises the specific steps as follows:

[0038] 1. Working foundation pits 10 are excavated at both sides of the multi-track existing railway, wherein the sidewall of each working foundation pit 10 is made of formwork concrete, which not only guarantees the stability of the foundation pit, but also serves as a reaction wall for pipe section jacking of the frame bridge.

[0039] 2. The jacking pipe sections 1 are prefabricated in the working foundation pits 10.

[0040] 3. A pile hole is dug below the existing railway according to the load design, with a hole digging depth above groundwater level; then a temporary overhead pile 3 is casted, and an upper overhead component is erected with the pile top of the temporary overhead pile 3 as a fulcrum.

[0041] 4. Dewatering by a broached groove: after the transition overhead in the step three is completed, working grooves 4 are constructed below the existing railway and between the temporary overhead piles 3 in each row, foundation pit fender piles 5 and dewatering wells 12 are constructed by using working faces in the working grooves 4, and then dewatering is carried out to enable the ground water level to reach the designed water level. The dewatering wells 12 are distributed at both sides of the multi-track existing railway and in the working grooves, and the dewatering wells 12 are mechanically constructed.

[0042] 5. A pile hole is dug beneath the temporary overhead pile 3 below the existing railway, with a hole digging depth below the groundwater level, and then the formal overhead pile 6 is casted, and a horizontal lifting beam 9 is arranged in a penetrating manner with the pile top of the formal overhead pile 6 as a fulcrum so as to form an overhead system.

[0043] 6. After the step five is completed, the prefabricated jacking pipe sections 1 are jacked in the overhead system from both sides of the multi-track existing railway by using a jack. A triangular correction block 11 is arranged at one side of the pipe section baseplate 1-2 of the jacking pipe section 1, such that the jacking pipe section 1 and the existing railway are constructed in a skew jacking manner.

[0044] 7. Overhead conversion is carried out by means of pile breaking while jacking, after the jacking pipe sections 1 on both sides of the multi-track existing railway are jacked in place, the jacking pipe sections serve as a supporting structure by replacing the overhead pile, a construction space of a middle cast-in-place pipe section 2 is formed by erecting the horizontal lifting beam 9; and a pipe section 2 is cast in place between the jacking pipe sections 1;

[0045] 8, after the pipe sections 2 are cast in place, regarding that the construction of the frame bridge underpass multi-track existing railway is completed, dismounting the overhead equipment to recover the normal operation of the railway.