CN-116512417-B - Industrial construction method and construction system for urban rail intersection thin-wall mixed-tensioning U-shaped beam

CN116512417BCN 116512417 BCN116512417 BCN 116512417BCN-116512417-B

Abstract

The invention discloses an industrial construction method and a construction system for urban rail intersection thin-wall mixed-tensioning U-shaped beams, wherein the construction of a U-shaped beam manufacturing pedestal and a beam storage tensioning pedestal is carried out in a field, U-shaped beam steel bar binding and prestress steel beam installation are carried out on a U-shaped beam tire membrane frame, a U-shaped beam steel bar cage is hung on the beam manufacturing pedestal through a hanging bracket, an embedded part, a U-shaped beam inner die and a supporting system are installed after the U-shaped beam steel bar cage is in place, the structure of the thin-wall mixed-tensioning U-shaped beam is optimized, pretension prestress beam construction is carried out, steel pouring beam body concrete is carried out, pretension prestress beam placing and cutting are carried out, two U-shaped beams are respectively hung on the beam storage tensioning pedestal by adopting a gantry crane, post pretension prestress beam construction is carried out, grouting and sealing are carried out on a tunnel, quartz sand is discharged through a sand discharging hole of a steel sand box after the whole operation is completed, and the U-shaped beam is lowered onto a concrete base of the beam storage tensioning pedestal. The invention comprehensively and systematically solves the problems of large resource waste and low production efficiency in the prior art.

Inventors

Deng Xiangzhen
Xing Wenkang
LI HUI
GE NING
FAN XIAOYE
WANG DAPENG
CHEN HAO
GUO JIANQIANG
ZHAO LIANJUN

Assignees

中建八局第三建设有限公司
南京地铁建设有限责任公司

Dates

Publication Date: 20260505
Application Date: 20230331

Claims (5)

1. An industrialized construction method for urban rail intersection thin-wall mixed-tensioning U-shaped beams is characterized by comprising the following steps: S1, constructing a U-shaped beam manufacturing pedestal and a beam storage tensioning pedestal in a site, wherein the beam manufacturing pedestal supports 2U-shaped beams at one time, and a U-shaped beam bottom die, an outer die and a steam curing shed are synchronously installed during construction of the beam manufacturing pedestal; S2, binding U-shaped beam steel bars on a U-shaped beam tire membrane frame and installing a prestress steel beam to obtain a U-shaped beam steel bar cage, and hanging the U-shaped beam steel bar cage onto a beam manufacturing pedestal by using a gantry crane through a hanging frame; S3, installing an embedded part after the U-shaped beam reinforcement cage is in place, and positioning an inner die, an inner die support, an inner die moving system and an end die of the U-shaped beam; S4, optimizing the side wall structure of the thin-wall mixed-tensioned U-shaped beam, namely calculating the thickness of the side wall of the U-shaped beam according to the stress characteristics of the U-shaped beam with different spans, analyzing the stress born by each part of the beam body, and reinforcing the area with the largest stress; S5, pre-tensioning prestress beam construction, namely adopting a construction process of simultaneously tensioning two U-shaped beams, wherein the tensioning process flow is that single ends are initially adjusted to 15% sigma con, the whole is tensioned to 100% sigma con and the load is maintained for 3min, sigma con anchoring is carried out, steam curing is adopted in construction, and the tensioning control stress is 0.7fpk+2 x At according to the actual temperature difference At between the steel beam and the pedestal; S6, pouring beam body concrete after the steel bar, the template and the prestress are checked and accepted; s7, pretensioning and cutting the pretensioned prestressed beam, and after the strength of the concrete reaches 85% and the elastic modulus reaches 90%, tensioning the prestressed beam; S8, after the steel sand box is put into tension, two U-shaped beams are respectively hoisted to a beam storage tensioning pedestal by adopting a gantry crane, and at the moment, the beam storage tensioning pedestal is in a state of being jacked up by the steel sand box, and the steel sand box is stressed and continuous automatic spraying maintenance is carried out; S9, post-tensioning prestressed bundle construction, wherein after the concrete strength reaches 95% of a design value and the elastic modulus reaches 100% of the design value and the age is not less than 7 days, the post-tensioning prestressed bundle construction is carried out, and two ends are synchronously tensioned, wherein the tensioning process flow comprises 0-0.1 sigma con-0.2 sigma con, tensioning control stress sigma con and anchoring for 5 min; S10, grouting a pore canal, sealing an anchor, performing pipeline vacuum auxiliary grouting within 48 hours after final pulling is completed, sealing a pretensioned sleeve by using epoxy mortar, and using C60 fine stone micro-expansion concrete for a back Zhang Shufeng anchor; S11, after the whole operation is finished, discharging quartz sand through a sand discharging hole of a steel sand box, enabling the U-shaped beam to descend onto a concrete base of a beam storage tensioning pedestal, converting stress of the end part of a stress point of the U-shaped beam into stress of a support seat position, and transporting the U-shaped beam to field erection after the U-shaped beam is stored for a specified time; The beam making pedestal in the S1 comprises a pedestal foundation, reaction piers, tensioning beams, dowel bars and a bottom die platform, wherein the bottom die platform is arranged at the top of the pedestal foundation, the tensioning beams are arranged at two sides of the bottom die platform, and the reaction piers are arranged at the outer sides of the tensioning beams; the beam storage tensioning pedestal in the S1 comprises a concrete base and a steel sand box, wherein the steel sand box is arranged at the outer side corner of the concrete base and is connected with the concrete base through embedded bars; And in the step S4, according to the stress characteristics of the U-shaped beams with different spans, the side walls of the U-shaped beams are adopted to resist the centrifugal force generated by train operation, meanwhile, a MIDAS CIVIL is adopted to establish a design checking model, the stress on each part of the beam body is analyzed, the steel beam area with the largest stress is obtained, and the C12 threaded steel bars are adopted to manufacture spiral bars and steel bar meshes for reinforcement.
2. The industrial construction method of the urban rail intersection thin-wall mixed tension U-shaped beam is characterized in that S5 is characterized in that an anchor clamp is firstly arranged at the fixed end of a girder manufacturing pedestal one by one to anchor a prestress beam, a sleeve which is tightly pressed against a clamping piece is used for knocking the clamping piece, connectors are arranged at the tensioning end one by one and one by one, two sleeves are tightly screwed by half-moon-shaped wrenches and straighten the prestress beam, the anchor clamp at the tensioning end is finally arranged at one by one, 2 jacks for 30t are used for construction after tensioning one by one, construction is carried out through 4 jacks for 600t after all prestress beams are tensioned to 15% sigma con, at this time, the counterforce pier is stressed, stress sensor data are rechecked after the stress pier is held for 3min through the reinforcement of the reserved tensioning holes of the counterforce pier, and the I-steel is anchored after the stress is not damaged, and the prestress beam is tensioned after the stress is controlled if the prestress beam is smaller than sigma con.
3. The industrial construction method of the urban rail intersection thin-wall mixed-tensioning U-shaped beam, which is characterized in that the S7 tensioning process is that the two ends are synchronously tensioned, the tensioning steps are 10% -10% -20%, the tensioning time interval is 1 minute, after the tensioning, the steel strands at the exposed part of the beam end are cut off by a manual abrasive wheel cutting machine, and the exposed steel strand heads outside the beam body are coated with antirust materials according to design requirements.
4. The industrial construction method of the urban rail intersection thin-wall mixed-tensioning U-shaped beam is characterized in that the whole construction process adopts informatization control and is divided into three flows of information acquisition, data processing and information output; The information acquisition comprises the steps of adjusting parameters of concrete mixing proportion according to different seasons, checking performance indexes of raw materials, meeting design requirements, putting into production, adjusting and optimizing tensioning control stress according to a single prestress beam control stress obtained by acquisition before construction and pedestal and prestress beam temperature obtained by measurement, and judging whether tensioning is in place or not according to actual stress fed back by a stress collector in the tensioning process; The data processing comprises the steps of establishing a standard database according to the design content of the concrete mixing proportion, the performance index of raw materials and the design standard of prestress beam control stress, formulating a control index, carrying out data comparison through information acquisition in the construction process, and determining that the construction requirement is met after the relevant requirement is met, entering the next working procedure; the information output comprises the steps of independently establishing a file for each U-shaped beam after construction is completed, including three contents including materials, construction and monitoring, making a two-dimensional code according to the file contents, posting the two-dimensional code at the striking position of the U-shaped beam, and linking the two-dimensional code to the file contents.
5. The construction system for realizing the urban rail intersection thin-wall mixed-tensioning U-shaped beam industrialized construction method is characterized by comprising a beam manufacturing pedestal, a U-shaped beam template system, a steam curing shed, intelligent tensioning equipment and a beam storage tensioning pedestal for storing the thin-wall mixed-tensioning U-shaped beam, wherein the beam manufacturing pedestal, the U-shaped beam template system and the intelligent tensioning equipment are used for preparing the thin-wall mixed-tensioning U-shaped beam; The beam making pedestal comprises a pedestal foundation, a counter-force pier, a tensioning beam, a dowel bar and a bottom die platform, wherein the dowel bar is arranged in the middle of the pedestal foundation, the bottom die platform is arranged above the pedestal foundation and used for supporting the U-shaped beam template system, the tensioning beam is respectively arranged on two sides of the bottom die platform, intelligent tensioning equipment is arranged at the tensioning beam, the counter-force pier is arranged on the outer side of the tensioning beam, the counter-force pier is connected with the pedestal foundation through pre-buried I-steel to form steel reinforced concrete, tensioning holes are reserved in the counter-force pier, steel plates are arranged on two sides of each tensioning hole for reinforcement, and jacks are arranged on the outer side of the counter-force pier; The beam storage tensioning pedestal comprises a concrete base and a steel sand box, wherein the steel sand box is arranged at the outer side corner of the concrete base and is connected with the concrete base through embedded bars, a base and quartz sand filled on the base are arranged in the steel sand box, a top cover is supported above the quartz sand, and a sand unloading hole is formed in the middle of the steel sand box.

Description

Industrial construction method and construction system for urban rail intersection thin-wall mixed-tensioning U-shaped beam Technical Field The invention relates to the technical field of U-shaped beam production, in particular to an industrialized construction method and a construction system for urban rail intersection thin-wall mixed U-shaped beams. Background The prestressed concrete U-shaped beam has the technical characteristics of low building height, good noise reduction effect, high section space utilization rate, guaranteed driving safety, attractive appearance, good visual effect, low comprehensive manufacturing cost, easy maintenance of the whole structure and the like. However, the U-shaped beam is not applied in China at present, and the corresponding construction technology is not perfect. The pre-stressing concrete structure of the constant-section prefabricated U-shaped Liang Duowei is formed by stretching a pre-stressing steel beam on a pedestal, pouring concrete and establishing pre-stressing through adhesive force transmission. According to the structural design characteristics of the U-shaped beam, the constant-section U-shaped beam cannot meet the requirements of safe running of vehicles, cable bridge installation and attractive appearance in a small curve radius section, and the constant-section U-shaped beam is designed into a variable-section thin-wall mixed-open U-shaped beam. The variable cross-section thin-wall mixed-tensioned U-shaped beam is provided with prestress steel bundles except for the bottom plate area, and the bending prestress steel bundles are needed to be additionally arranged on the thin-wall areas on two sides. The technical characteristics of pretensioning prestressing construction are that the bending prestressing beam cannot be tensioned, and the post-tensioning construction is adopted after the concrete is poured and the strength required by the design is reached. The two working areas of the Nanjing-Jurong intercity rail traffic engineering DS6-TA02 are one-stop-one area, the adopted irregular complex appearance is a double-U-shaped variable cross section girder, and the following problems can occur in the construction of the thin-wall mixed U-shaped girder: 1. The length of the U-shaped beam with the variable cross section between the adjacent cities is 26m, 28m, 30m and the like, and the cross section area of the prestress steel beam is 0.014m2 by taking the 5.21-5.41 variable cross section 28 mU-shaped beam as an example, the total number of the prestress steel beams is 102, and the single prestress beam has different relaxation coefficients and different lengths, so that the tension is time-consuming and labor-consuming, the overall tension stress is difficult to control and the like. 2. According to the established model simulation checking calculation, the post-tensioning prestress beam tensioning notch of the U-shaped beam is subjected to the largest stress, and concrete cracking is easy to occur. 3. The thin-wall mixed-tensioning U-shaped beam construction has 3 more working procedures than the standard section construction, and occupies long time for beam manufacturing pedestal and template, so that the engineering cost and the construction period are correspondingly increased. Disclosure of Invention The invention aims to provide an industrialized construction method and a construction system for an urban rail intersection thin-wall mixed-tensioning U-shaped beam, which solve the problems of difficult control of tensioning stress, easy structural damage, resource waste and the like in the production process of the thin-wall mixed-tensioning U-shaped beam, improve construction efficiency and increase benefits. The technical scheme is that the industrialized construction method of the urban rail intersection thin-wall mixed-tensioning U-shaped beam comprises the following steps: S1, constructing a U-shaped beam manufacturing pedestal and a beam storage tensioning pedestal in a site, wherein the beam manufacturing pedestal supports 2U-shaped beams at one time, and a U-shaped beam bottom die, an outer die and a steam curing shed are synchronously installed during construction of the beam manufacturing pedestal; S2, binding U-shaped beam steel bars on a U-shaped beam tire membrane frame and installing a prestress steel beam to obtain a U-shaped beam steel bar cage, and hanging the U-shaped beam steel bar cage onto a beam manufacturing pedestal by using a gantry crane through a hanging frame; S3, installing an embedded part after the U-shaped beam reinforcement cage is in place, and positioning an inner die, an inner die support, an inner die moving system and an end die of the U-shaped beam; S4, optimizing the side wall structure of the thin-wall mixed-tensioned U-shaped beam, namely calculating the thickness of the side wall of the U-shaped beam according to the stress characteristics of the U-shaped beam with different spans, analyzing the stress born