CN-116695570-B - Construction method of up-span railway cast-in-situ beam

CN116695570BCN 116695570 BCN116695570 BCN 116695570BCN-116695570-B

Abstract

The invention discloses a construction method of an over-span railway cast-in-situ beam, which mainly comprises the construction of a swivel of a T-shaped cast-in-situ beam and an over-span cast-in-situ beam, wherein the construction is carried out on a section of the T-shaped cast-in-situ beam, a pre-swivel step is arranged, the formal swivel is guided by monitoring data of the pre-swivel, and the construction of a bracket system of the over-span cast-in-situ beam is carried out while the T-shaped cast-in-situ beam is constructed, so that the construction efficiency is improved, and the safety of the overall construction of the over-span railway cast-in-situ beam is guaranteed.

Inventors

WANG XUEQIANG
WU DONG
JIN ZHUANG
GUO XIAOSONG
WANG HAILONG
WANG BING
WANG XIAOWEN
CAI TAIPING
LI XIAOYI
LI HUAN

Assignees

中铁七局集团有限公司
中铁七局集团武汉工程有限公司

Dates

Publication Date: 20260505
Application Date: 20230607

Claims (6)

1. The construction method of the upper span railway cast-in-situ beam is characterized by comprising the steps of turning section cast-in-situ construction of a T-structure cast-in-situ beam, turning section turning construction and side span cast-in-situ section construction, and specifically comprises the following steps of: s1, a T-structure cast-in-situ beam corresponds to three adjacent piers, wherein one pier is positioned on the north side of a railway, the other two piers are positioned on the south side of the railway, the middle pier is a swivel main pier, the other two piers are transition piers, firstly, site three-way one-level construction is carried out, and pile foundations, bearing platforms, pier bodies and capping beams of the three piers are synchronously constructed; s2, performing cast-in-situ construction on a turning section of the T-shaped cast-in-situ beam on the south side along the direction parallel to a railway, wherein the turning section is cast-in-situ and divided into 4 sections, a cast-in-situ beam support system consisting of a cast-in-situ bored pile, a steel pipe column and a cast-in-situ beam support is adopted, the cast-in-situ beam support consists of a Bailey sheet and a disc buckle support frame, concrete pouring and tensioning grouting are sequentially completed on the sections, and monitoring and protection auxiliary facility construction on two sides of the turning section are synchronously performed; S3, after the two transition piers and the swivel segment reach the design strength and are accepted, detaching a disc buckle supporting frame corresponding to the swivel segment, completing preparation work before swivel and performing anticlockwise test swivel, then formally swivel to a design position in a vertical skylight point, fixing the position of a beam body after the posture adjustment of the beam body is completed, and simultaneously, erecting a bracket system of a side span cast-in-place segment at two sides of the swivel segment, and prepressing, wherein a space reserved by the bracket system does not influence swivel construction; When the bracket system of the side span cast-in-place section is erected, firstly, a drilling bored concrete pile foundation is arranged on one side of the transition pier facing the swivel main pier, a group of sleeves are arranged on the top of the drilling bored concrete pile foundation, grouting holes are formed in the bottoms of the side walls of the sleeves, grouting pipes are connected to the grouting holes, switching valves are arranged on the grouting pipes, the bracket system comprises steel pipe columns which are vertically arranged in an array, a circle of supporting rings are connected to the outer sides of the lower ends of the steel pipe columns, the supporting rings are used for anchoring with the tops of the drilling bored concrete pile foundation, the inner sides of the bottoms of the steel pipe columns are of closed structures, the bottoms of the steel pipe columns extend downwards into a sleeve, the outer diameter of the steel pipe columns are matched with the inner diameter of the sleeve, the supporting rings are higher than the tops of the sleeves, a circle of sealing telescopic film is connected between the tops of the outer sides of the sleeves and the parts of the steel pipe columns below the supporting rings, a row of pile caps are fixedly arranged on the tops of each steel pipe column, a row of pile caps are welded together, a transverse distribution beam is welded on the tops of all transverse distribution beams, a row of longitudinal distribution beams are longitudinally arranged along a bridge, a row of longitudinal distribution beam is welded on the tops of the bridge, a vertical distribution beam is arranged at the tops of the bridge, a vertical distribution beam is also used for buckling the tops of the bridge, a static force gauge is arranged at the tops of the transition bridge, and a vertical bridge is used for the bridge, and a level bridge is arranged at the top; When the height difference measured by the static level exceeds a set threshold, symmetrically arranging jacks below supporting rings of the steel pipe columns with lower heights, lifting the heights corresponding to the height difference through the jacks, connecting a grouting pipe with a grouting pump, opening a switching valve, injecting quick setting cement into a space in the bottom of the steel pipe columns in a sleeve, closing the switching valve, and removing the jacks after the quick setting cement reaches the setting time, wherein the bottom of the corresponding steel pipe column is born on the quick setting cement; S4, pouring side span cast-in-situ section concrete after the swivel is completed, and completing prestress tensioning grouting; s5, dismantling a bracket system of the side span cast-in-situ section to complete system conversion, and constructing an auxiliary structure of the anti-collision guardrail, the bridge deck pavement and the bridge deck drainage.
2. The construction method of the over-railway cast-in-situ beam according to claim 1, wherein the foundation treatment is carried out on the region where the swivel main pier is located, irrigation pipe culverts exist at the upper and lower row lines of the corresponding railway, the irrigation pipe culverts traverse the cast-in-situ beam support region, backfilling is carried out on the cast-in-situ beam support region, the bearing capacity of the backfilled foundation is controlled to be not less than 300kpa, the irrigation ditch in the range of the cast-in-situ beam support region is changed, and concrete circular pipe culverts are pre-buried in the cast-in-situ beam support region.
3. The construction method of the on-site railway cast-in-situ beam according to claim 1, wherein the cast-in-situ beam support is pre-pressed, the pre-pressing load is 1.1 times of the maximum construction load borne by the cast-in-situ beam support, the pre-pressing area is divided into a plurality of pre-pressing units during pre-pressing, the pre-pressing units are symmetrically loaded and loaded in three stages according to the loading sequence of the on-site railway to the two ends, the three stages of loading sequentially is 60%, 80% and 100% of the pre-pressing load value in the pre-pressing units, and the pre-pressing is performed in the unloading sequence, then the pre-pressing is performed, and then the pre-pressing is performed, so that the pre-pressing is uniformly unloaded.
4. The construction method of the over-railway cast-in-situ beam according to claim 1, wherein 6 monitoring points are distributed at the center line and the side line at the two ends of the top surface of the beam body in total during the construction of the swivel section swivel, the monitoring points of the top surface of the beam body are measured by using a high-precision automatic standard total station in the process of testing the swivel, and after the test is finished, the data are analyzed, and the rotation speed, the horizontal chord length of the rotating cantilever, the elevation change condition of the end heads of the beam body and the elevation change condition of the two sides of the beam body are calculated as reference technical parameters; And erecting an automatic standard total station on the large and small mileage sides of the swivel pier respectively, constructing a station by adopting a rear intersection, measuring the plane position of a monitoring point by adopting a polar coordinate method, measuring the elevation of the monitoring point by using a triangle Gao Chengfa, synchronously measuring by using two measuring stations, reporting the swivel angle, checking the measurement data of the two automatic standard total stations by using the observation points at the two ends of the point-moving synchronous measuring beam body when the swivel enters the final point movement, wherein the error is less than or equal to 2mm, and taking the average value as the observation data until the swivel is in place.
5. The construction method of the over-railway cast-in-situ beam according to claim 1, wherein a scissor brace is connected between adjacent steel pipe columns, and the longitudinal rod, the small stupefied square timber and the bottom die bamboo plywood are sequentially arranged on the disc buckle type bracket upwards; when the measured height difference of the static level exceeds a set threshold, the jacks are symmetrically arranged below the supporting rings of the steel pipe column at the bottom of one end with the lower corresponding measured height of the longitudinal rod.
6. The construction method of the over-railway cast-in-place beam according to claim 5, wherein a plurality of stiffening ribs are connected between the surface of the stay ring and the outer side wall of the steel pipe column.

Description

Construction method of up-span railway cast-in-situ beam Technical Field The invention relates to the technical field of bridge construction. More particularly, the invention relates to a construction method of an up-span railway cast-in-situ beam. Background In bridge construction engineering of an overstock railway, due to the existence of lower railway traffic and the fact that the length of a beam body part of the overstock railway is larger, the whole bridge is divided into a plurality of different parts to be respectively constructed and then combined into a complete bridge, the current common construction mode is to divide the beam body of the overstock bridge into two parts, the bridge piers at two sides of the railway are respectively constructed by adopting a suspension casting method and then folded above the railway, but the mode is not suitable for the condition that the clearance between the beam body and a railway business line carrier cable is smaller, and swivel systems are respectively arranged at two sides of the railway, so that the construction cost is high, the butt joint difficulty of swivel directions is high, and the construction efficiency is lower. Disclosure of Invention It is an object of the present invention to solve at least the above problems and to provide at least the advantages to be described later. The invention also aims to provide a construction method of the over-span railway cast-in-situ beam, which aims at solving the technical problems of lack of mature and stable construction scheme and low overall construction efficiency when the clear distance between the bridge and the railway is smaller in the prior art. To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a construction method of an over-span railway cast-in-place beam, including a swivel-section cast-in-place construction of a T-structure cast-in-place beam, a swivel-section swivel construction, and a side-span cast-in-place section construction, comprising the steps of: S1, a T-shaped cast-in-situ beam corresponds to three adjacent piers, one transition pier is positioned on the north side of a railway, the other transition pier and the turning main pier are positioned on the south side of the railway, the middle pier is the turning main pier, the other two piers are transition piers, firstly, site three-way one-level construction is carried out, and pile foundations, bearing platforms, pier bodies and capping beams of the three piers are synchronously constructed; s2, performing cast-in-situ construction on a turning section of the T-shaped cast-in-situ beam on the south side along the direction parallel to a railway, wherein the turning section is cast-in-situ and divided into 4 sections, a cast-in-situ beam support system consisting of a cast-in-situ bored pile, a steel pipe column and a cast-in-situ beam support is adopted, the cast-in-situ beam support consists of a Bailey sheet and a disc buckle support frame, concrete pouring and tensioning grouting are sequentially completed on the sections, and monitoring and protection auxiliary facility construction on two sides of the turning section are synchronously performed; S3, after the two transition piers and the swivel segment reach the design strength and are accepted, detaching a disc buckle supporting frame corresponding to the swivel segment, completing preparation work before swivel and performing anticlockwise test swivel, then formally swivel to a design position in a vertical skylight point, fixing the position of a beam body after the posture adjustment of the beam body is completed, and simultaneously, erecting a bracket system of a side span cast-in-place segment at two sides of the swivel segment, and prepressing, wherein a space reserved by the bracket system does not influence swivel construction; S4, pouring side span cast-in-situ section concrete after the swivel is completed, and completing prestress tensioning grouting; s5, dismantling a bracket system of the side span cast-in-situ section to complete system conversion, and constructing an auxiliary structure of the anti-collision guardrail, the bridge deck pavement and the bridge deck drainage. Preferably, the foundation treatment is carried out on the region where the swivel main pier is located, irrigation pipe culverts exist at the upper and lower row lines of the corresponding railways, the irrigation pipe culverts transversely penetrate through the cast-in-situ beam support region, backfilling is carried out on the cast-in-situ beam support region, the backfilling foundation bearing capacity is controlled to be not less than 300kpa, the irrigation ditch in the range of the cast-in-situ beam support region is changed, and concrete circular culverts are pre-buried in the cast-in-situ beam support region. Preferably, the cast-in-situ beam support is pre-pressed, the pre-pressin