Full-prefabricated assembly type bridge integrated installation process

Abstract

The invention discloses a full-prefabricated assembly type bridge integrated installation technology. The technology comprises the following steps that 1, prefabricated parts are hoisted and transported; the construction method comprises the following steps of 1, installation of a prefabricated advanced pier, 2, installation of an advanced pier column, 3, installation of a main span small box girder, 4, installation of a prefabricated advanced pier cover beam, 5, span crossing of a bridge girder erection machine and 6, safety monitoring. The overall construction sequence of the process comprises the following steps: mounting an advanced pier column, mounting a main-span small box girder, mounting an advanced pier cover beam, crossing a bridge girder erection machine, and carrying out the next construction cycle. According to the integrated bridge girder erection machine, overturning, rotating and hoisting of prefabricated parts are achieved through the integrated bridge girder erection machine, the functions of half-range transportation and full-range erection of a bridge deck are achieved through the front supporting leg ground rail of the integrated bridge girder erection machine, and safe and reliable operation of installation operation is ensured through a real-time monitoring system. Therefore, environmental protection, quality, safety and efficiency of construction operation of a construction unit are greatly improved, the construction progress is accelerated, and related workloads are relieved.

Description

Technical Field

[0001] The invention relates to the field of bridge construction, and in particular to an integrated installation process for a fully prefabricated assembled bridge. Background Art

[0002] At present, the construction method of bridge structure is still mainly based on manual binding and on-site pouring. The problems and disadvantages exposed by the cast-in-place bridge construction method during the construction process include: the need to set up a large number of scaffolds and formworks on site and tie steel bars, etc., and the overall shortcomings are complex construction technology, a large number of construction workers, unstable construction quality, long operation time, great impact on existing traffic, prominent environmental protection issues, and a lot of material waste.

[0003] Prefabricated and assembled bridges are made by dividing the blocks into reasonable parts, breaking them down into smaller parts. The components that were originally cast as a whole on site are transferred to the factory for prefabrication in sections and then assembled on site into a whole. They have the characteristics of standardized design, factory production, assembly construction, and information management.

[0004] The common existing construction methods are as follows: (1) The existing construction mainly consists of on-site binding and pouring of the foundation and the lower structure + an upper ordinary bridge erection machine. The foundation and the lower structure are bound and poured on site. The main construction steps are: original ground treatment → pile foundation construction → pedestal construction → pier construction → cap beam construction → support cushion stone construction. The upper ordinary bridge erection machine has the following main construction steps: beam lifting and beam transport point setting → prefabricated component transportation → bridge erection machine erection → bridge erection machine through the hole, and the cycle ends at the end of half width. The same steps are used to install the other half width; (2) Crawler crane / truck crane + ordinary bridge erection machine. Since crawler crane / truck crane has high requirements for the standing site, a large amount of site treatment is usually required. After the site treatment is completed, the crane is hoisted. Similar to the process of the present invention, the prefabricated piers and prefabricated cap beams are hoisted, and the upper structure is erected by an ordinary bridge erection machine. Disadvantages of the existing technology: The overall performance is high energy consumption, heavy pollution, low efficiency, and extensiveness; it is necessary to carry out foundation treatment on site, set up a large number of brackets and templates, and tie steel bars. Summary of the invention

[0005] Purpose of the invention: The present invention proposes an integrated installation process for a fully prefabricated assembled bridge, which solves the problems of unstable construction quality, long operation time, great impact on existing traffic, prominent environmental protection issues, large material waste, and great social impact.

[0006] Technical solution: The present invention proposes an integrated installation process for a fully prefabricated assembled bridge, comprising the following steps:

[0007] S1: Lifting and transportation of prefabricated components; prefabricated components include prefabricated advanced pier columns, prefabricated main span small box beams and prefabricated advanced pier cap beams;

[0008] S2: Installation of prefabricated leading pier columns; including: lifting the front end of the prefabricated leading pier columns by the front crane, lifting the rear end of the prefabricated leading pier columns by the rear crane, lowering the bottom of the prefabricated leading pier columns and making the prefabricated leading pier columns vertical; and then installing the prefabricated leading pier columns to the predetermined position of the cap by the longitudinal and transverse movement of the front crane;

[0009] S3: Installation of prefabricated main span small box beam; including: lifting the front end of the prefabricated main span small box beam by the front crane, lifting the rear end of the prefabricated main span small box beam 3 by the rear crane, and the rear crane and the front crane moving forward synchronously until the prefabricated main span small box beam is longitudinally lifted into place, and then installing the prefabricated main span small box beam to the predetermined position;

[0010] S4: Installation of prefabricated advanced pier cap beam; including: when the prefabricated advanced pier cap beam is lifted to the middle of the first leg and the second leg by the front crane, the prefabricated advanced pier cap beam is rotated 90 degrees and then installed above the erected prefabricated advanced pier column; the first leg and the second leg are preset legs of the bridge erection machine;

[0011] S5: bridge erection machine crosses the span;

[0012] S6: Cycle S1-S5 construction.

[0013] Preferably, in S1, two gantry cranes are used at the lifting point, and the lifting process includes two-point lifting of the prefabricated advanced pier columns by a single gantry crane and two nylon slings; four-point lifting of the prefabricated advanced pier cap beam by a single gantry crane and two nylon slings; and lifting of the prefabricated main span small box beam by two gantry cranes and two steel wire ropes at both ends; the transportation process includes transporting the prefabricated advanced pier columns, prefabricated main span small box beams and prefabricated advanced pier cap beams from the prefabrication site to the beam lifting gantry crane, and then transferring them from the beam lifting point to the beam transport vehicle.

[0014] Preferably, the S2 specifically includes the following steps:

[0015] S2.1: Preparation before construction of prefabricated advanced pier columns;

[0016] S2.2: The beam transport vehicle feeds the prefabricated leading pier column to the tail of the bridge erecting machine and stops at the position where the front crane can lift it;

[0017] S2.3: The front crane lifts the front end of the prefabricated leading pier column, and the rear crane lifts the rear end of the prefabricated leading pier column. The front crane and the rear crane move forward synchronously. When the front crane moves close to the leading pier, the front crane and the rear crane stop moving.

[0018] S2.4: The post-crane lowers the bottom of the prefabricated leading pier column until the prefabricated leading pier column is naturally vertical, and the bottom of the prefabricated leading pier column falls on the top surface of the cap;

[0019] S2.5: The front crane and the rear crane move backward until the prefabricated leading pier column is in a vertical state, and the rear crane automatically releases the bottom hanger of the prefabricated leading pier column;

[0020] S2.6: The crane hoists the prefabricated advanced pier column and installs it to the predetermined position of the pedestal through the longitudinal and transverse movement of the crane; repeat steps S2.1-S2.5 to install another prefabricated advanced pier column; when the other prefabricated advanced pier column is hoisted into place, the steel bar positioning cradle shall be used to adjust the prefabricated advanced pier column installed later to ensure that the top steel bars of the two piers are accurately positioned, and then the grouting is used to connect them. After 24 hours of strengthening, the top positioning cradle of the prefabricated advanced pier column shall be removed.

[0021] Preferably, the preparation before construction of the prefabricated advanced pier column in S2.1 specifically includes: inspecting the cap and embedded steel bars, detecting the exposed length of the embedded steel bars, the steel bar coordinates, and the horizontality of the cap surface, the exposed length deviation of the embedded steel bars is -2 to 0 mm, the steel bar coordinate deviation is 0 to 2 mm, and the cap surface horizontality deviation is 0 to 5 mm; marking and roughening the splicing surface of the cap and the pier column to expose the aggregate, and the rough surface has a concave-convex depth of ≥ 6 mm; installing the slurry retaining template, the limiting angle plate, the slurry stopping pad and the adjusting pad, and A circle of slurry retaining formwork is installed, which is located on the periphery of the advance pier column. Four limiting angle plates are arranged on the slurry retaining formwork. The slurry retaining formwork and the limiting angle plates are fixed to the pedestal. The diameter of the slurry retaining formwork is 5cm larger than the size of the prefabricated advance pier column. A slurry stopping pad is installed on the embedded steel bar, which is 3cm away from the splicing surface. Four adjusting pads are placed at the center of the splicing surface of the pedestal. The pads have a diameter of 10cm and a height of ≤2cm. A steel corbel is installed in each of the four directions of the longitudinal and transverse axes of the pier column, and the corbel hole matches the grouting sleeve hole.

[0022] Preferably, the S3 specifically includes the following steps:

[0023] S3.1: Preparation before construction of prefabricated main span small box girder;

[0024] S3.2 The prefabricated main span small box girder is fed to the tail of the bridge erecting machine by the girder transport vehicle and stops at a position where the front crane can lift it;

[0025] S3.3: The front crane lifts the front end of the prefabricated main span small box girder and moves forward synchronously with the beam transport vehicle until it stops at the position where the rear crane can lift;

[0026] S3.4: The rear crane lifts the rear end of the prefabricated main span small box girder and moves forward synchronously with the front crane until the prefabricated main span small box girder is lifted longitudinally into place;

[0027] S3.5: The front crane and the rear crane drop the beams synchronously. When they are at a certain height from the support, the prefabricated main span small box beams are installed to the predetermined position by the overall horizontal movement of the front crane and the rear crane. Then, S3.1-S3.4 are repeated in sequence to complete the installation of the remaining prefabricated main span small box beams.

[0028] Preferably, the S3.1 prefabricated main span small box girder construction preparation specifically includes the following steps:

[0029] S3.1.1: Installation of pot-type bearings: Place the cross center line of the bearing at the position of the bearing pad stone, and roughen the joint part between the bearing pad stone and the bearing. The depth of the rough surface should not be less than 6mm to expose uniform aggregate; place the leveling bolt on the top of the pier cap beam ahead of the outer side of the bearing pad stone, and adjust the height of the grouting template; install the bearing to the corresponding position, weld the leveling steel plate to the steel plate on the bearing, and install the leveling steel plate according to the slope of the drawing; align the cross line on the bearing with the ink line popped up on the bearing pad stone in advance, then rotate the leveling bolt, and adjust the elevation in conjunction with the measurement; install the template 5cm outside the bearing, the template height must be higher than the steel plate under the bearing, and the bearing is fixed by grouting;

[0030] S3.1.2: Installation of temporary sand cylinder supports: Temporary sand cylinders are made of steel sand cylinders, and the relative height difference of the top surfaces of temporary sand cylinder supports on the same box girder shall not exceed 2mm.

[0031] Preferably, the S4 specifically includes the following steps:

[0032] S4.1: Preparation before construction of prefabricated advanced pier cap beam;

[0033] S4.2: The prefabricated advanced pier cap beam is fed to the tail of the bridge erecting machine by the beam transport vehicle and stops at a position where the front crane can lift it;

[0034] S4.3: The single vehicle of the front crane lifts the prefabricated advanced pier cap beam and moves forward;

[0035] S4.4: When the crane hoists the prefabricated advanced pier cap beam to the middle of the first leg and the second leg, the electric rotation function on the hoist is started;

[0036] S4.5: Rotate the prefabricated leading pier cap beam 90 degrees by the electric rotating hanger on the front crane;

[0037] S4.6: Install the prefabricated advanced pier cap beam onto the erected prefabricated advanced pier column by moving the crane vertically and horizontally;

[0038] S4.7: Complete the anchoring between the precast advance pier column and the precast advance pier cap beam by pipe grouting.

[0039] Preferably, the preparations before construction of the prefabricated advanced pier cap beam in S4.1 specifically include: re-measurement of the central axis of the prefabricated advanced pier column; re-measurement of the elevation of the top of the prefabricated advanced pier column; straightening the embedded steel bars, and measuring and verifying the spacing and position of the embedded steel bars; popping up the ink line for positioning the bottom of the prefabricated advanced pier cap beam in the prefabrication yard; roughening and cleaning the concrete interface at the junction of the top of the advanced pier and the prefabricated advanced pier cap beam, with the roughening depth of not less than 6mm; installing a grout retaining hoop on the top surface of the prefabricated advanced pier column, the size of the grout retaining hoop is consistent with the cross-sectional size of the prefabricated advanced pier column, and the hoop is 30mm higher than the top of the pier column when installed; according to the elevation of the top surface of the prefabricated advanced pier cap beam and the height of the prefabricated advanced pier cap beam, adjust the elevation of the center pad on the top of the advanced pier column.

[0040] Preferably, the S5 specifically includes the following steps:

[0041] S5.1: After the bridge erection machine completes the installation of the prefabricated advanced pier cap beam, it will start crossing the span within 24 hours of waiting for strength;

[0042] S5.2: The position of the bridge erection machine when the prefabricated advanced pier cap beam is erected and the two-carriage vehicle returns;

[0043] S5.3: The fifth outrigger supports, the fourth outrigger is retracted and moved forward 10m to the rear of the third outrigger for re-support;

[0044] S5.4: Lift the fourth leg, allowing the third leg to hang forward for one span, and then re-support at the next span position;

[0045] S5.5: The second outrigger is retracted and moved forward by one span to the top of the cap beam of the next span for re-support;

[0046] S5.6: The fourth outrigger is retracted again and the vehicle moves forward for 20 m before being supported again;

[0047] S5.7: Driven by the second leg, the third leg and the fourth leg anti-support wheels, the main beam of the bridge-erecting machine is sent forward 30m, the bridge-erecting machine crosses the span in one go, anchors the connection between each leg and the main beam, and adjusts the position of the front and rear cranes so that the bridge-erecting machine has the conditions to erect prefabricated advanced pier columns, prefabricated main span small box beams and prefabricated advanced pier cap beams.

[0048] Preferably, steps S1 to S6 are also monitored throughout the process, including the following steps:

[0049] S7.1: Stress / strain monitoring of bridge erecting machine: Through the structural analysis and calculation of the bridge erecting machine under various working conditions and the on-site construction conditions, the key sections and key rods of the main beam and the first leg are determined, and monitoring points are selected at the key sections and key rods and fiber Bragg grating strain sensors are installed; the stress monitoring points of the main beam are located near the main beam legs and in the middle of each span, and the key load-bearing rods should be selected for stress monitoring of the first leg;

[0050] S7.2: Bridge erecting machine inclination monitoring: The main beam inclination monitoring position is arranged near each span leg, the first leg inclination monitoring position is at its top, and inclination detectors are installed at each inclination monitoring position;

[0051] S7.3: Safety monitoring uses the following algorithmic process to evaluate the effectiveness of monitoring data:

[0052] S7.3.1: According to the actual working conditions of data collection, all data are divided into M categories, U = {Q1, Q2…QM}, where M is the working condition type;

[0053] S7.3.2: Divide all data into N categories according to their own characteristics, U = {P1, P2...PN};

[0054] S7.3.3: Set classification error parameters;

[0055] S7.3.4: For each class Pi, i = 1, 2...N, determine whether it can be included by the majority of any class Qj (j = 1, 2...M);

[0056] S7.3.5: Merge all Pi, i=1, 2...N that satisfy the majority inclusion relationship, and count the proportion of the number of elements in the set to the total data, which is the evaluation result.

[0057] Beneficial effects: (1) The present invention proposes an integrated installation process for a fully prefabricated assembled bridge, which adopts an integrated installation bridge-building machine that can move the entire bridge in two widths. The machine has a total length of 80m and adopts a two-and-a-half-span structure. It is equipped with a hydraulically adjustable front support leg and supported on the pedestal ground rail. The pedestal top horizontal track is used to move the prefabricated components on the bridge in a single width, and the bridge-building machine is used to install the prefabricated components in a double width. At the same time, a circular pier aerial flipping device and an electric rotating device are configured to realize the vertical flipping of the prefabricated pier by 90° in the air, and the horizontal rotation of the prefabricated leading pier cap beam by 90° in the air, so as to accurately install the prefabricated components.

[0058] (2) The overall process of the integrated installation process of a fully prefabricated assembled bridge proposed in the present invention is: installing the advanced pier columns → installing the small box girder of the main span → installing the advanced pier cap beam → the bridge-erecting machine passing the span → the next construction cycle. Compared with the original installation sequence of the pier columns, the cap beam, and the small box girder, the main span small box girder can be installed and prepared for the bridge-erecting machine to pass the span after the advanced pier columns and the advanced pier cap beam are grouted. There is no need to wait for the strength to be increased, which effectively improves the erection energy efficiency and realizes the full-width cycle erection construction.

[0059] (3) The present invention proposes an integrated installation process for a fully prefabricated assembled bridge, which is equipped with a cap pre-embedded steel bar positioning frame and a pier top positioning frame. The cap pre-embedded steel bar positioning frame can accurately position the relative positions of the cap pre-embedded steel bars and the prefabricated pier column sleeve; the pier top positioning frame can accurately position the relative positions of the top steel bars of the prefabricated pier column and the reserved corrugated pipe of the prefabricated advanced pier cap beam, and can control the longitudinal and transverse axes and relative positions of the pier column, thereby meeting the construction requirements and improving the construction efficiency, assembly accuracy and installation quality.

[0060] (4) This patent discloses an integrated installation process for a fully prefabricated and assembled bridge, which is equipped with a monitoring system and a black box that monitors parameters such as strain, displacement, and inclination. It monitors adverse working conditions in real time, sets reasonable monitoring frequencies and early warning thresholds for adverse cross-sections under adverse working conditions, and automatically alarms and sends information when the values ​​are exceeded, thus achieving online real-time safety monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is an overall structural diagram of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0062] Figure 2 This is a schematic diagram of transporting the prefabricated leading pier column of the present invention;

[0063] Figure 3 This is a schematic diagram of transporting the prefabricated main span small box girder of the present invention;

[0064] Figure 4 This is a schematic diagram of transporting the prefabricated advanced pier cap beam of the present invention;

[0065] Figure 5 This is a side view schematic diagram of step 2.2 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0066] Figure 6 This is a side view schematic diagram of step 2.3 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0067] Figure 7 This is a side view schematic diagram of step 2.4 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0068] Figure 8 This is a side view schematic diagram of step 2.5 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0069] Fig. 9 This is a side view schematic diagram of step 2.6 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0070] Fig.10 This is a side view schematic diagram of step 3.2 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0071] Fig.11 This is a side view schematic diagram of step 3.3 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0072] Fig.12 This is a side view schematic diagram of step 3.4 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0073] Fig.13 This is a side view schematic diagram of step 3.5 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0074] Fig.14 This is a side view schematic diagram of step 4.2 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0075] Fig.15 This is a side view schematic diagram of step 4.3 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0076] Fig.16 This is a side view schematic diagram of step 4.4 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0077] Fig.17 This is a side view schematic diagram of step 4.5 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0078] Fig.18 This is a front view of step 4.5 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0079] Fig.19 This is a side view schematic diagram of step 4.6 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0080] Fig. 20 This is a front view of step 4.6 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0081] Fig.21 This is a side view schematic diagram of step 4.7 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0082] Fig. 22 This is a side view schematic diagram of step 5.2 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0083] Fig.23 This is a side view schematic diagram of step 5.3 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0084] Fig.24 This is a side view schematic diagram of step 5.4 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0085] Fig.25This is a side view schematic diagram of step 5.5 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0086] Fig.26 This is a side view schematic diagram of step 5.6 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0087] Fig. 27 This is a side view schematic diagram of step 5.7 of the integrated installation process of the fully prefabricated assembled bridge of the present invention;

[0088] Fig.28 A schematic diagram of the distribution of stress monitoring measuring points for safety monitoring of the present invention;

[0089] Fig.29 A schematic diagram of the distribution of inclination monitoring points for safety monitoring of the present invention;

[0090] Fig.30 It is a side view of the auxiliary supporting tire frame of the present invention;

[0091] Fig.31 This is a front view of the auxiliary tire frame of the present invention;

[0092] Fig.32 It is a partial schematic diagram of the hoisting of the prefabricated advanced pier cap beam of the present invention;

[0093] Fig.33 A front view of a control frame for the installation accuracy of pier columns according to the present invention;

[0094] Fig.34 A top view of a control frame for the installation accuracy of pier columns according to the present invention.

[0095] Among them, 1. bridge erecting machine; 2. prefabricated advanced pier column; 3. prefabricated main span small box beam; 4. prefabricated advanced pier cap beam; 5. beam transport vehicle; 6. front crane; 7. rear crane; 8. fiber grating strain sensor; 9. inclination detector; 10. pedestal; 11. first leg; 12. second leg; 13. third leg; 14. fourth leg; 15. fifth leg. DETAILED DESCRIPTION

[0096] Combined with Figure 1-Figure 34 The scheme of the present invention is described. Generally, the abutment and the pier of the assembled bridge are connected by grouting sleeves, and the pier and the cap beam are connected by grouting bellows. According to the characteristics of the connection joints of the lower structure of the assembled bridge and the design characteristics of the integrated bridge erection machine, in order to avoid the delay of the installation time of the integrated bridge erection machine caused by the strong grouting material of the lower component construction joint, the construction adopts the following installation process: install the prefabricated advanced pier pier 2 → install the main span small box beam 3 → install the prefabricated advanced pier cap beam 4 → bridge erection machine 1 crosses the span, and the construction is cyclically carried out until the construction is completed.

[0097] A fully prefabricated and assembled bridge integrated installation process, such as Figures 1 to 34 As shown, it mainly includes the setting of the beam lifting area, the lifting and transportation of prefabricated components, the installation of prefabricated advanced pier columns 2, prefabricated advanced pier cap beams 4, prefabricated main span small box beams 3, safety monitoring, etc. Figure 1 This is an overall front view of the implementation process of the present invention. The integrated installation process of a fully prefabricated assembled bridge proposed by the present invention includes the following steps:

[0098] (1) Lifting and transportation of prefabricated components;

[0099] (2) Installation of prefabricated leading pier column 2;

[0100] (3) Installation of prefabricated main span small box girder 3;

[0101] (4) Installation of prefabricated advanced pier cap beam 4;

[0102] (5) Bridge erecting machine 1 crosses the span;

[0103] (6) Repeat steps (1) to (5) to perform construction.

[0104] (1) Lifting and transportation of prefabricated components:

[0105] (1.1) Setting of the beam area:

[0106] Two 95t pier-spanning gantry cranes are installed in the beam lifting area. The gantry crane track is 120m long with 4 holes, including 1 hole for simple beam storage area and 3 holes for initial installation area for bridge erection machine. The width covers the width of the full-width bridge beam transportation channel. It can be used in conjunction with an integrated bridge erection machine frame or an ordinary highway bridge erection machine.

[0107] The main channel for transporting beams is to loosen the original ground by 50cm and add 5% lime, with a compaction degree of not less than 93%, compacted by a roller, and then paved with 30cm thick construction waste and compacted, and then poured with a 25cm thick C25 concrete surface layer. The original surface is cleared, leveled and compacted, and 30cm of construction waste is laid and compacted, and a 10cm thick C25 concrete surface layer is poured in the general area.

[0108] The beam storage pedestal is arranged perpendicular to the direction of the gantry crane track in the beam storage area. The bottom of the pedestal is replaced with 50cm thick 5% ash soil, and 50cm thick construction waste is laid on it for compaction. The foundation of the beam storage pedestal adopts an expanded foundation, and C30 concrete is poured. A sleeper beam is set on the foundation, and C30 concrete is poured; the expanded foundation is 1m wide and 0.3m high, and the sleeper beam is 0.5m wide and 0.3m high. The box beam is stored in two layers, and 20cm×15cm sleepers are used as pads between layers. The center spacing of the beam storage pedestal is consistent with the spacing of the beam and slab supports, and is controlled within 80cm along the length of the beam from the beam end to the inside. The gantry crane adopts an expanded foundation, and the original surface is cleared and compacted. A 50cm thick 5% ash soil is laid, and then 50cm of construction waste is laid and compacted. After pouring a 5cmC20 concrete cushion layer, a 30cm high expanded foundation is made;

[0109] (1.2) Lifting of prefabricated components:

[0110] The beam transport vehicle 5 is parked on the beam transport channel beside the rack, and the prefabricated leading pier column 2 is hoisted by the gantry crane. Two 85t-class flexible fixed-load slings are used to unload the vehicle and hoist it horizontally onto the flip frame. The frame is mainly made of 135*135*12 square tubes that are bent and welded. Rubber pads are pasted in the "V"-shaped support frame groove to ensure that the surface of the prefabricated leading pier column 2 is not damaged when it is placed (see Fig.30 and Fig.31 ).

[0111] Four lifting rings are set on the prefabricated advanced pier cap beam 4 as the installation and lifting points of the prefabricated advanced pier cap beam 4. The lifting rings are made of low-relaxation high-strength prestressed steel strands with a specification of φs15.2mm, a nominal area of ​​140mm2 per strand, a standard value of tensile strength fpk=1860MPa, and a design value of tensile strength fpd=1260Mpa. The beam transport vehicle 5 is parked under the gantry crane, and a single 95t gantry crane single hook is used to lift the prefabricated advanced pier cap beam 4 to unload the vehicle. The unloading rigging is 4 Φ52-8m steel wire ropes and 4 55t grade American standard bow shackles.

[0112] The beam transporter 5 is parked under the gantry crane, and two 95t gantry cranes are used to lift the prefabricated main span small box beam 3. The prefabricated main span small box beam 3 is hoisted by a wire rope with one ring and three bottoms, and the hoisting point is about 1.5m away from the beam end. The hoisting rigging of the prefabricated main span small box beam 3 is 2 Φ36 steel wire ropes, and the force meets the construction requirements.

[0113] (1.3) Transportation of prefabricated components:

[0114] The transportation of prefabricated components is divided into two parts: one is the offline transportation from the prefabrication site to the bottom of the beam lifting door, and the other is the online transportation from the beam lifting point to the tail of the bridge erecting machine 1 after being transferred to the beam transport vehicle 5 from the beam lifting point.

[0115] Offline transportation is similar to online transportation. After the components are transported to the beam lifting gantry crane, the prefabricated components are unloaded from the transport vehicle and transferred to the beam transport vehicle 5. The prefabricated leading pier column 2 is transported by the ground beam transport vehicle to the beam lifting area, and then lifted by the gantry crane in the beam lifting area and transferred to the beam transport vehicle 5 (see Figure 2 ), the prefabricated main span small box beam 3 is pulled by the ground beam transport vehicle to the beam lifting area, and then lifted by the gantry crane in the beam lifting area and transferred to the beam transport vehicle 5 (see Figure 3 ), the prefabricated leading pier cap beam 4 is also pulled by the ground beam transport vehicle to the beam lifting area, and then lifted by the gantry crane in the beam lifting area and transferred to the beam transport vehicle 5 (see Figure 4 ).

[0116] The online transportation mainly adopts two sets of 200t tire-type beam transporters, and the transportation route is along the built box beam bridge deck. ① The beam transporter 5 stops on the bridge deck under the beam lifting door; ② Different brackets or turntables are installed according to different prefabricated components. The prefabricated leading pier column 2 is installed with a "V"-shaped bracket during transportation, and the prefabricated leading pier cap beam 4 is installed with a flat heightening bracket during transportation. The prefabricated main span small box beam 3 is directly placed on the original turntable of the beam transporter 5 during transportation; ③ Rubber thin wood boards or sleepers are laid on the "V"-shaped bracket, or flat bracket, or turntable, and the prefabricated components are installed on the bracket or turntable; ④ The vehicle is fixed and sealed, and the two ends of the prefabricated component are pulled and fixed with a fall chain. At the same time, the two ends of the prefabricated main span small box beam 3 need to be supported by a brace to support the lower flange; ⑤ The beam transporter 5 pulls the prefabricated component along the bridge deck to the tail of the bridge erection machine 1; ⑥ The beam transporter 5 cooperates with the bridge erection machine 1 to feed the component, and the bridge erection machine 1 completes the installation of the prefabricated component.

[0117] The loading plan is based on the safety of the equipment as the most fundamental principle. When sealing and bundling the vehicle, steel wire ropes and slings are used to anchor the prefabricated beams to the 5 turntables of the beam transport vehicle; the most important joint point when loading prefabricated beams is to press the center of gravity of the goods to the center of the vehicle plate, and the left and right deviations cannot exceed 3cm. After loading is completed, warning lights are installed around the beams; after all transport vehicles are loaded with equipment, in addition to sealing the vehicle firmly, the equipment loading position is reasonable, and loading is carried out according to the pre-established technical plan, special attention should be paid to the consistency of tire pressure, and the deviation of each tire pressure should not exceed 0.5 air pressure.

[0118] (2) Installation of prefabricated leading pier column 2:

[0119] (2.1) Preparation before construction of prefabricated advanced pier column 2;

[0120] (2.2) The beam transport vehicle 5 feeds the prefabricated leading pier column 2 to the rear of the bridge erecting machine 1 and stops at a position where the front crane 6 can lift it (see Figure 5 );

[0121] (2.3) The front crane 6 lifts the front end of the prefabricated leading pier column 2, and the rear crane 7 lifts the rear end of the prefabricated leading pier column 2. The front crane 6 and the rear crane 7 move forward synchronously. When the front crane 6 moves to the position close to the leading pier, the front crane 6 and the rear crane 7 stop moving. (See Figure 6 );

[0122] (2.4) The rear crane 7 slowly lowers the bottom of the prefabricated leading pier column 2 until the prefabricated leading pier column 2 is nearly vertical, and the bottom of the prefabricated leading pier column 2 falls to the ground (see Figure 7 );

[0123] (2.5) The front crane 6 and the rear crane 7 move backward until the prefabricated leading pier column 2 is in a vertical state, and the rear crane 7 releases the bottom hanging device of the prefabricated leading pier column 2 (see Figure 8 );

[0124] (2.6) The front crane 6 lifts the prefabricated leading pier column 2, and installs the prefabricated leading pier column 2 to the predetermined position of the foundation 10 by moving the front crane 6 vertically and horizontally; the same steps are used to install another prefabricated leading pier column 2 (see Fig. 9 ); When the other prefabricated leading pier column 2 is hoisted into place, a steel bar positioning frame shall be used (see Fig.33 , 34 ) Make fine adjustments to the prefabricated advanced pier column 2 to ensure that the top reinforcements of the two columns are accurately positioned, and then grout the connections. After strengthening for 24 hours, remove the top positioning frame of the prefabricated advanced pier column 2.

[0125] The preparations before construction specifically include: inspecting the cap 10 and embedded steel bars, testing the exposed length of the embedded steel bars, steel bar coordinates, cap surface level, etc. The exposed length of the steel bars is not allowed to have positive errors, and the negative error deviation is -2mm; checking whether the steel bar coordinates and the cap surface level deviation are within 2mm and 5mm respectively; marking and roughening the splicing surface of the cap 10 and the pier to expose the aggregate, and the rough surface concave and convex depth is not less than 6mm; installing the slurry retaining formwork, limiting angle plate, slurry stop pad and adjustment pad, and the slurry retaining formwork adopts 6 Made of No. 3 angle steel, each side is 5cm larger than the size of the prefabricated advanced pier column 2; expansion bolts are used to position the grouting template, the limiting angle plate and the cap 10; the grouting pad is 3cm away from the bottom surface, and an adjustment steel pad is placed at the center of the splicing surface. The pad is 10cm in diameter and should not be greater than 2cm in height. The pad size is 150mm×150mm, and the thickness is 20mm, 16mm, 2mm and other specifications; a steel bracket is installed in each of the four directions of the longitudinal and transverse axes of the pier column, and the bracket hole matches the grouting sleeve hole for easy corresponding installation. Prefabricated advanced pier column 2 trial hoisting: the splicing surface is not grouting, the prefabricated advanced pier column 2 is hoisted and aligned, and preliminary adjustments are made. The prefabricated advanced pier column 2 is plane limited and adjusted with the help of the grouting template on the splicing surface of the cap. After the adjustment, lock the adjustment wire on the limiting angle plate, record the position and height of the jacks in the four directions, and lock the jacks to prevent the jacks from loosening. Base mortar on the pedestal surface: clean and moisten the roughened surface of the pedestal, remove surface water, and ensure that there is no water mark on the pedestal surface; Mixing and spreading of base mortar: the mortar cushion between the pedestal and the prefabricated advanced pier column 2 uses C60 matching special base mortar, and the mortar mixing equipment uses a forced mixer. The mixing time is 3 minutes. Pour the mixed base mortar on the roughened surface of the pedestal and scrape it flat with an iron plate. Prefabricated advanced pier column 2 is hoisted into place: After the base mortar is spread, the prefabricated advanced pier column 2 is hoisted for the second time. During the lowering process, ensure that slurry is squeezed out from all sides to ensure that the base mortar is dense; clean the extruded mortar, and smooth the mortar surface and the mortar template so that the mortar surface is below the grouting port. Adjustment of relative position of prefabricated advanced pier column 2: To ensure the subsequent installation accuracy requirements of prefabricated advanced pier cap beam 4, before grouting the sleeves of two single advanced pier columns 2, a positioning frame is made according to the spacing, quantity and relative position of the embedded steel bars of prefabricated advanced pier column 2. The deviation between the hole diameter of the positioning frame and the diameter of the embedded sleeve of prefabricated advanced pier cap beam 4 is controlled within 2mm. The top frame of prefabricated advanced pier column 2 is inserted into the adjusted embedded steel bars of prefabricated advanced pier column 2, and the verticality and spacing of the embedded steel bars are checked. Sleeve grouting connection: The grouting material uses C100 high-strength non-shrinkage cement grouting material, and a forced mixer is used to stir for 6 minutes; the grouting process is that the slurry is discharged from the upper grouting outlet of the lower grouting hole, and the slurry rises to the outlet of the L-shaped pipe. After the slurry flows out evenly, the slurry inlet valve is closed and the grouting is stopped.

[0126] The prefabricated leading pier column 2 is flipped in the air and lifted to a position close to the leading pier by two cranes. The front and rear cranes move toward the front crane 6 and lower the wire rope to rotate the prefabricated leading pier column 2 vertically by 90 degrees to a vertical state. Then, the grouting is performed in sequence, the position of the prefabricated leading pier column 2 is roughly adjusted, the matching corbels are installed, the position of the prefabricated leading pier column 2 is finely adjusted, the precision control device of the prefabricated leading pier column 2 is installed, and grouting is performed.

[0127] (3) Installation of prefabricated main span small box girder 3:

[0128] (3.1) Preparation before construction of prefabricated main span small box girder 3;

[0129] (3.2) The prefabricated main span small box beam 3 is fed by the beam transport vehicle 5 to the tail end of the bridge erection machine 1 and stops at a position where the front crane 6 can lift it (see Fig.10 );

[0130] (3.3) The front crane 6 lifts the front end of the prefabricated main span small box beam 3, moves forward synchronously with the beam transport vehicle 5, and stops at the position where the rear crane 7 can lift (see Fig.11 );

[0131] (3.4) The rear crane 7 lifts the rear end of the prefabricated main span small box girder 3 and moves forward synchronously with the front crane 6 until the prefabricated main span small box girder 3 is lifted longitudinally into place (see Fig.12 );

[0132] (3.5) The front crane 6 and the rear crane 7 drop the beam synchronously. When the beam is at a certain height from the support, the front crane 6 and the rear crane 7 are moved horizontally as a whole to install the prefabricated main span small box beam 3 to the predetermined position, and the remaining prefabricated main span small box beams 3 are installed in a cycle (see Fig.13 ).

[0133] Small box girders generally have 4 pieces / hole for a single span and 8 pieces / hole for a double span. Regardless of whether it is an integrated bridge-erecting machine or an ordinary bridge-erecting machine, the order of erecting beams follows the principle of erecting the side beams first and then the middle beams for a single span, so as to adjust the overall line shape of the bridge. The prefabricated advanced pier cap beam 4 lifting rigging has an electric rotating mechanism on the upper part and a special hanger for the prefabricated advanced pier cap beam 4 on the lower part. When the bridge-erecting machine 1 has installed the prefabricated advanced pier pier column 2 and the prefabricated main span small box girder 3, it needs to be replaced with this hanger to install the prefabricated advanced pier cap beam 4. When replacing the hanger, you only need to remove the pin shaft at the bottom of the rotating hanger to achieve quick replacement (see Fig.32 ).

[0134] Among them, the prefabricated main span small box girder 3 pre-construction preparation: (3.1.1) Installation of pot-type bearings: the cross center line of the bearing is released at the position of the bearing pad stone, and the joint part of the bearing pad stone and the bearing is roughened, and the depth of the rough surface is not less than 6mm; the leveling bolt is placed on the top of the pier cap beam ahead of the outer side of the bearing pad stone, and the height of the grouting template is adjusted; the bearing is installed to the corresponding position, and the leveling steel plate is welded to the steel plate on the bearing in time. The placement direction of the leveling steel plate is installed according to the slope of the drawing; the cross line on the bearing is aligned with the ink line popped up on the bearing pad stone in advance, and then the leveling bolt is rotated to adjust the elevation in conjunction with the measurement; the template is installed 5cm outside the bearing, and the template height must be higher than the lower steel plate of the bearing. The loose part of the lower mouth is filled with foaming agent; C60 bearing special grouting material is used to pour the gap between the lower part of the bearing and the anchor hole, and the grouting is carried out by gravity grouting. (3.2.1) Installation of temporary sand cylinder support: The temporary sand cylinder adopts a steel sand cylinder with a diameter of 180mm and a wall thickness of 8mm. After testing, when the bearing capacity reaches 1000kN, the height of the sand cylinder is compressed by 25mm. During on-site installation, the temporary sand cylinder is controlled to be 30mm higher than the bottom of the precast beam. For each temporary sand cylinder support in the same box beam, the relative height difference of its top surface should not exceed 2mm. Prefabricated main span small box beam 3 is hoisted in place: Prefabricated main span small box beam 3 is hoisted by Ф52-8m steel wire rope, and an L-shaped corner protector with a wall thickness of 5mm is set at the bottom plate, and a 1mm thick veneer wrapped steel wire rope is used on the outer part of the flange plate. Beam drop: The prefabricated main span small box beam 3 is dropped in the order of side plate first and then middle plate to ensure that the outer edge line of the bridge deck is smooth. After each beam is installed, the end and mid-span elevations are measured to ensure that the beam top elevation meets the requirements.

[0135] (4) Installation of prefabricated advanced pier cap beam 4:

[0136] (4.1) Preparation before construction of prefabricated advanced pier cap beam 4;

[0137] (4.2) The prefabricated advanced pier cap beam 4 is fed by the beam transport vehicle 5 to the tail end of the bridge erection machine 1 and stops at a position where the front crane 6 can lift it (see Fig.14 );

[0138] (4.3) The front crane 6 lifts the prefabricated leading pier cap beam 4 and moves forward (see Fig.15 );

[0139] (4.4) When the crane 6 lifts the prefabricated advanced pier cap beam 4 to the middle of the first leg 11 and the second leg 12, the electric rotation function on the lifting device is started (see Fig.16 );

[0140] (4.5) The prefabricated leading pier cap beam 4 is rotated 90 degrees by the electric rotating hanger on the front crane 6 (see Fig.17 and Fig.18 );

[0141] (4.6) The prefabricated leading pier cap beam 4 is installed above the prefabricated leading pier column 2 by moving the front crane 6 vertically and horizontally (see Fig.19 and Fig. 20 );

[0142] (4.7) The anchoring between the prefabricated advanced pier column 2 and the prefabricated advanced pier cap beam 4 is completed by pipeline grouting (see Fig.21 ).

[0143] Among them, the preparations before the construction of the prefabricated advanced pier cap beam 4 include: re-measurement of the central axis of the prefabricated advanced pier column 2, marking the ink line on the top of the prefabricated advanced pier column 2, and the subsequent assembly of the prefabricated advanced pier cap beam 4 is controlled according to the new central ink line to avoid the accumulation of assembly errors of the prefabricated advanced pier cap beam 4 causing a deviation value exceeding 5mm. At the same time, the top elevation of the prefabricated advanced pier column 2 is remeasured to provide a basis for installing the thickness of the supporting pads when assembling the prefabricated advanced pier cap beam 4. The difference in top elevation of the two prefabricated advanced pier column 2 pads is controlled within 3mm; the embedded steel bars are straightened, and the spacing and position of the embedded steel bars are measured and verified, and the embedded steel bars are rusted and the debris on the top of the column is cleaned; at the prefabrication site, two ink lines corresponding to the center of the prefabricated advanced pier column 2 at the bottom of the prefabricated advanced pier cap beam 4 are all marked, and the third ink line is marked on site, that is, one point is extended from the center line of the bottom of the prefabricated advanced pier cap beam 4 to the bottom of the outer baffle, and another point is extended from the center line of the spine beam to the top of the baffle. Points, the line connecting the two points is the position of the third ink line; the concrete interface at the junction of the advance pier top and the prefabricated advance pier cap beam 4 is roughened and cleaned, and the roughening depth is not less than 6mm; the grout retaining hoop is installed on the top surface of the prefabricated advance pier column 2. The hoop is made of No. 63 angle steel, the angle plate is 5mm thick, and the size is consistent with the cross-sectional size of the prefabricated advance pier column 2. When the hoop is installed, it is 30mm higher than the top of the prefabricated advance pier column 2; according to the top surface elevation of the prefabricated advance pier cap beam 4 and the height of the prefabricated advance pier cap beam 4, adjust the elevation of the center pad on the top of the prefabricated advance pier column 2 to ensure that the elevation meets the design requirements after the prefabricated advance pier cap beam 4 is installed. Prefabricated advance pier cap beam 4 trial hoisting: observe and adjust the transverse center position of the prefabricated advance pier cap beam 4. Use a ruler close to the center ink line of the prefabricated advance pier column 2, and press the ruler against the bottom of the prefabricated advance pier cap beam 4 to measure the deviation between the center ink line of the part of the prefabricated advance pier cap beam 4 that laterally hangs out of the prefabricated advance pier column 2 and the center line of the prefabricated advance pier column 2, and the deviation is controlled within 5mm; the prefabricated advance pier cap beam 4 is adjusted in the longitudinal direction of the bridge, and the center ink line of the outer baffle is observed by the total station, and the center ink line of the outer baffle is adjusted to be plumb to the ground, parallel to the center line of the prefabricated advance pier column 2, and the deviation is controlled within 5mm. Mortaring of the top of the advanced pier: clean the dust and moisten the top surface of the prefabricated advanced pier column 2, and finally ensure that there is no water mark on the top surface of the prefabricated advanced pier column 2. After the trial lifting of the prefabricated advanced pier cap beam 4 is completed, lift the prefabricated advanced pier cap beam 4 and move it out of the range of the prefabricated advanced pier column 2. Move the retaining hoop upward to 3 cm above the top surface of the prefabricated advanced pier column 2, and tighten the nut. Use a climbing vehicle to carry out mortaring of the top of the pier. The mortaring requires that the mortar is evenly laid, higher than the adjustment pad, and flush with the top surface of the hoop. Lifting of the prefabricated advanced pier cap beam 4 into place: slowly lift the prefabricated advanced pier cap beam 4. When it is lifted 10 cm higher than the top steel bar of the prefabricated advanced pier column 2, lower the prefabricated advanced pier cap beam 4 to the designed position by adjusting the overhead crane. During the process of hoisting the prefabricated advanced pier cap beam 4 into place, the construction workers use traction ropes to guide the installation of the prefabricated advanced pier cap beam 4 from the transverse bridge and the longitudinal bridge.After the hoisting is completed, the overflow slurry is flushed with high-pressure water. Prefabricated advanced pier cap beam 4 grouting: The slurry mixing equipment uses a forced mixer with a mixing time of 6 minutes. The entire slurry mixing process is consistent with the grouting of the prefabricated advanced pier column 2. C100 high-strength non-shrinkage cement grouting material is used to start grouting from the lower end slurry inlet to fill all cavities. When the slurry from the slurry outlet flows out of the thick slurry in a round shape, the slurry outlet can be blocked in time. When the grouting of an operating surface is completed, the slurry inlet valve is immediately blocked. The pressure of the high-pressure grouting pump used for grouting is not less than 3MPa, and the displacement is not less than 4L / min.

[0144] (5) Bridge erecting machine 1 crosses the span;

[0145] (5.1) After the bridge erection machine 1 completes the installation of the prefabricated advanced pier cap beam 4, the bridge erection machine 1 starts to cross the span within 24 hours of waiting for strength;

[0146] (5.2) The station status of the bridge erecting machine 1 after erecting the prefabricated advanced pier cap beam 4 and the two-carriage vehicle returning (see Fig. 22 );

[0147] (5.3) The fifth leg 15 supports, the fourth leg 14 is retracted and moved forward 10m to the rear of the third leg 13 and then supported again (see Fig.23 );

[0148] (5.4) The fourth leg 14 is lifted up, so that the third leg 13 is suspended in the air and moves forward for a span, and then re-supported at the next span position (see Fig.24 );

[0149] (5.5) The second leg 12 is retracted and moved forward one span to the top of the cap beam of the next span to support it again (see Fig.25 );

[0150] (5.6) The fourth leg 14 is retracted again and moved forward for 20 m before being supported again (see Fig.26 );

[0151] (5.7) The main beam of the bridge erecting machine 1 is sent forward 30m under the drive of the second leg 12, the third leg 13 and the fourth leg 14. The bridge erecting machine 1 crosses the span in one go, anchors the connection between each leg and the main beam, and adjusts the position of the front and rear cranes so that the bridge erecting machine 1 is ready to erect the prefabricated advanced pier column 2, the prefabricated main span small box beam 3 and the prefabricated advanced pier cap beam 4 (see Fig. 27 ).

[0152] Before the start of each operation, the operator will first ring the bell to indicate that the on-site personnel are in position and ready to enter the working state. During the crossing process, the front outrigger tools are placed in the designated position, and safety protection is done below. A dedicated person observes the gap between the rotation of the middle outrigger support wheel and the main beam, as well as the gap between the middle outrigger hanging wheel and the main beam hanging baffle to avoid jamming or scratching. When crossing a curved line segment or constructing on a ramp, the main beam of the bridge erector 1 can only be moved longitudinally after it is leveled. The horizontal degree of the full length of the main beam is not more than 1%. After the main beam is moved longitudinally into place, the middle outrigger and the main beam should be locked immediately. During longitudinal movement, the two overhead cranes are parked at the rear end of the bridge erector 1 for counterweighting and cannot move forward.

[0153] Conduct full safety monitoring of steps 1 to 6:

[0154] (7.1) Stress / strain monitoring of bridge erecting machine 1: Based on the structural analysis and calculation of the bridge erecting machine under various working conditions and the on-site construction conditions, the key sections and key rods of the main beam and the first leg 11 are determined. Monitoring points are selected at the key sections and key rods and fiber Bragg grating strain sensors 8 are installed. The stress monitoring points of the main beam are located near the main beam legs and in the middle of each span. The stress monitoring of the first leg 11 should select the key load-bearing rods (see Fig.28 );

[0155] (7.2) Tilt monitoring of the bridge erecting machine 1: Tilt monitoring is used to evaluate the structural deformation state of the bridge erecting machine 1 under construction conditions. The main beam tilt monitoring position is arranged near each span leg. The tilt monitoring position of the first leg 11 is located at the top of the first leg 11. Each tilt monitoring position is provided with a tilt detector 9 (see Fig.29 );

[0156] (7.3) Safety monitoring uses the following algorithm process to evaluate the effectiveness of monitoring data:

[0157] (7.3.1) According to the actual working conditions of data collection, all data are divided into M categories, U = {Q1, Q2…QM}, where M is the working condition type;

[0158] (7.3.2) According to the characteristics of the data itself, all data are divided into N categories, U = {P1, P2...PN};

[0159] (7.3.3) Set the classification error parameter;

[0160] (7.3.4) For each class Pi, i = 1, 2...N, determine whether it can be included by the majority of any class Qj (j = 1, 2...M);

[0161] (7.3.5) All Pi, i=1, 2...N that satisfy the majority inclusion relationship are merged, and the proportion of the number of elements in the set to the total data is counted, which is the evaluation result.

[0162] Analyze the real-time monitoring signal, and use the ratio of the stress value to the yield strength of the material as the safety factor of the bridge-building machine 1 structure. Evaluate the safety status of the bridge-building machine 1 by analyzing the safety factor. According to the calculation of the inclination angle of the key section and the anti-overturning verification under each working condition, compare the inclination monitoring data with the calculated value to judge the safety of the bridge-building machine 1 structure. Based on the abnormal stress and inclination data, establish a graded early warning system, and the risk levels are divided into red (extremely high risk), orange (high risk), yellow (medium risk) and blue (low risk). The corresponding risk levels correspond to on-site light alarms and buzzer alarms. The remote monitoring platform sends alarm information to the user end through SMS, email, etc. to guide on-site construction safety.

Claims

1. A fully prefabricated and assembled bridge integrated installation process, characterized in that: The following steps are involved: S1: lifting and transporting prefabricated components; the prefabricated components include prefabricated advanced pier columns (2), prefabricated main span small box beams (3) and prefabricated advanced pier cap beams (4); S2: Installation of the prefabricated leading pier column (2); including: lifting the front end of the prefabricated leading pier column (2) by the front crane (6), lifting the rear end of the prefabricated leading pier column (2) by the rear crane (7), lowering the bottom of the prefabricated leading pier column (2) and making the prefabricated leading pier column (2) vertical; and then installing the prefabricated leading pier column (2) to a predetermined position of the cap (10) by moving the front crane (6) vertically and horizontally; S3: installation of the prefabricated main span small box girder (3); comprising: lifting the front end of the prefabricated main span small box girder (3) by the front crane (6), lifting the rear end of the prefabricated main span small box girder 3 by the rear crane (7), the rear crane (7) and the front crane (6) moving forward synchronously until the prefabricated main span small box girder (3) is longitudinally lifted into place, and then installing the prefabricated main span small box girder (3) to a predetermined position; S4: installation of the prefabricated advanced pier cap beam (4); comprising: lifting the prefabricated advanced pier cap beam (4) to the middle of the first leg (11) and the second leg (12) by the front crane (6), rotating the prefabricated advanced pier cap beam (4) by 90 degrees and installing it above the erected prefabricated advanced pier column (2); the first leg (11) and the second leg (12) are preset legs of the bridge erection machine; S5: the bridge erecting machine (1) crosses the span; S6: Cycle S1-S5 construction.

2. The integrated installation process of a fully prefabricated assembled bridge according to claim 1 is characterized in that: In S1, two gantry cranes are used at the lifting point, and the lifting process includes two-point lifting of the prefabricated leading pier column (2) by a single gantry crane in cooperation with two nylon slings; four-point lifting of the prefabricated leading pier cap beam (4) by a single gantry crane in cooperation with two nylon slings; and lifting of the prefabricated main span small box beam (3) by two gantry cranes in cooperation with two steel wire ropes at both ends; and the transportation process includes transporting the prefabricated leading pier column (2), the prefabricated main span small box beam (3) and the prefabricated leading pier cap beam (4) from the prefabrication site to the beam lifting gantry crane, and then transferring them from the beam lifting point to the beam transport vehicle (5).

3. The integrated installation process for a fully prefabricated assembled bridge according to claim 1 is characterized in that: The S2 specifically includes the following steps: S2.1: Prefabrication of the advanced pier column (2) before construction preparation; S2.2: The beam transport vehicle (5) feeds the prefabricated leading pier column (2) to the rear of the bridge erecting machine (1) and stops at a position where the front crane (6) can lift it; S2.3: the front crane (6) lifts the front end of the prefabricated leading pier column (2), and the rear crane (7) lifts the rear end of the prefabricated leading pier column (2). The front crane (6) and the rear crane (7) move forward synchronously. When the front crane (6) moves to a position close to the leading pier, the front crane (6) and the rear crane (7) stop moving. S2.4: The rear crane (7) lowers the bottom of the prefabricated leading pier column (2) until the prefabricated leading pier column (2) is naturally vertical, and the bottom of the prefabricated leading pier column (2) falls on the top surface of the cap; S2.5: the front crane (6) and the rear crane (7) move backward until the prefabricated leading pier column (2) is in a vertical state, and the rear crane (7) automatically releases the bottom hanging device of the prefabricated leading pier column (2); S2.6: The front crane (6) lifts the prefabricated advanced pier column (2), and installs the prefabricated advanced pier column (2) to the predetermined position of the pedestal (10) by moving the front crane (6) vertically and horizontally; repeat steps (2.1)-(2.5) to install another prefabricated advanced pier column (2); when the other prefabricated advanced pier column (2) is hoisted into place, a steel bar positioning frame shall be used to adjust the prefabricated advanced pier column (2) installed later, so as to ensure that the top steel bars of the two columns are accurately positioned, and then the grouting is carried out to connect them, and the top positioning frame of the prefabricated advanced pier column (2) is removed after the strength is strengthened for 24 hours.

4. The integrated installation process for a fully prefabricated assembled bridge according to claim 3 is characterized in that: The preparation before construction of the prefabricated advanced pier column (2) in S2.1 specifically includes: inspecting the cap (10) and the embedded steel bars, detecting the exposed length of the embedded steel bars, the steel bar coordinates, and the horizontality of the cap surface, the exposed length deviation of the embedded steel bars is -2 to 0 mm, the steel bar coordinate deviation is 0 to 2 mm, and the cap surface horizontality deviation is 0 to 5 mm; marking and roughening the joint surface of the cap and the pier column to expose the aggregate, and the rough surface has a concave-convex depth of ≥ 6 mm; installing the grouting template, the limiting angle plate, the grouting pad and the adjusting pad, and installing the grouting pad on the top of the cap (10); A circle of grout-blocking templates is installed, the grout-blocking templates are located at the periphery of the leading pier column, four limiting angle plates are arranged on the grout-blocking templates, the grout-blocking templates and the limiting angle plates are fixed to the cap (10), and the diameter of the grout-blocking templates is 5 cm larger than the size of the prefabricated leading pier column (2); a grout-blocking pad is installed on the embedded steel bar, the grout-blocking pad is 3 cm away from the splicing surface, and four adjustment pads are placed at the center of the splicing surface of the cap (10), the pads have a diameter of 10 cm and a height of ≤2 cm; a steel bracket is installed in each of the four directions of the longitudinal and transverse axes of the pier column, and the bracket hole matches the grouting sleeve hole.

5. The integrated installation process for a fully prefabricated assembled bridge according to claim 1 is characterized in that: The S3 specifically includes the following steps: S3.1: Preparation before construction of prefabricated main span small box girder (3); S3.2 The prefabricated main span small box girder (3) is fed by the girder transport vehicle (5) to the rear of the bridge erection machine (1) and stops at a position where the front crane (6) can lift it; S3.3: The front crane (6) lifts the front end of the prefabricated main span small box girder (3), moves forward synchronously with the girder transport vehicle (5), and stops at a position where the rear crane (7) can lift the girder; S3.4: The rear crane (7) lifts the rear end of the prefabricated main span small box girder (3) and moves forward synchronously with the front crane (6) until the prefabricated main span small box girder (3) is lifted longitudinally into place; S3.5: The front crane (6) and the rear crane (7) drop the beams synchronously. When the beams are at a certain height from the support, the front crane (6) and the rear crane (7) are moved laterally as a whole to install the prefabricated main span small box beam (3) to the predetermined position. Steps (3.1) to (3.4) are repeated in sequence to complete the installation of the remaining prefabricated main span small box beams (3).

6. The integrated installation process for a fully prefabricated assembled bridge according to claim 5 is characterized in that: The S3.1 prefabricated main span small box girder (3) pre-construction preparation specifically includes the following steps: S3.1.1: Installation of basin-type bearings: The cross center line of the bearing is released at the position of the bearing pad stone, and the joint part of the bearing pad stone and the bearing is roughened, and the depth of the rough surface is not less than 6mm to expose uniform aggregate; the leveling bolt is placed on the top of the pier cap beam ahead of the outer side of the bearing pad stone, and the height of the grouting template is adjusted; the bearing is installed to the corresponding position, and the leveling steel plate is welded to the steel plate on the bearing. The placement direction of the leveling steel plate is installed according to the slope of the drawing; the cross line on the bearing is aligned with the ink line popped up on the bearing pad stone in advance, and then the leveling bolt is rotated to adjust the elevation in conjunction with the measurement; the template is installed 5cm outside the bearing, and the template height must be higher than the steel plate under the bearing, and the bearing is fixed by grouting; S3.1.2: Installation of temporary sand cylinder supports: Temporary sand cylinders are made of steel sand cylinders, and the relative height difference of the top surfaces of temporary sand cylinder supports on the same box girder shall not exceed 2mm.

7. The integrated installation process for a fully prefabricated assembled bridge according to claim 1 is characterized in that: The S4 specifically comprises the following steps: S4.1: Preparation before construction of prefabricated advanced pier cap beam (4); S4.2: The prefabricated advanced pier cap beam (4) is fed by the beam transport vehicle (5) to the rear of the bridge erection machine (1) and stops at a position where the front crane (6) can lift it; S4.3: The front crane (6) lifts the prefabricated leading pier cap beam (4) and moves forward; S4.4: When the crane (6) lifts the prefabricated advanced pier cap beam (4) to the middle of the first leg (11) and the second leg (12), the electric rotation function on the lifting device is activated; S4.5: Rotate the prefabricated leading pier cap beam (4) by 90 degrees using the electric rotating hanger on the front crane (6); S4.6: Install the prefabricated advanced pier cap beam (4) onto the erected prefabricated advanced pier column (2) by moving the front crane (6) vertically and horizontally; S4.7: Complete the anchoring between the prefabricated advanced pier column (2) and the prefabricated advanced pier cap beam (4) by pipeline grouting.

8. The integrated installation process for a fully prefabricated assembled bridge according to claim 7 is characterized in that: The preparations before construction of the prefabricated advanced pier cap beam (4) in S4.1 specifically include: re-measurement of the central axis of the prefabricated advanced pier column (2); re-measurement of the top elevation of the prefabricated advanced pier column (2); straightening of the embedded steel bars, and measuring and verifying the spacing and position of the embedded steel bars; popping up the bottom positioning ink line of the prefabricated advanced pier cap beam (4) in the prefabrication yard; roughening and cleaning the concrete interface at the junction of the advanced pier top and the prefabricated advanced pier cap beam (4), with the roughening depth not less than 6mm; installing a grout retaining hoop on the top surface of the prefabricated advanced pier column (2), the size of the grout retaining hoop being consistent with the cross-sectional size of the prefabricated advanced pier column (2), and the hoop being 30mm higher than the top of the pier column when installed; adjusting the elevation of the center pad on the top of the advanced pier column according to the top surface elevation of the prefabricated advanced pier cap beam (4) and the height of the prefabricated advanced pier cap beam (4).

9. The integrated installation process for a fully prefabricated assembled bridge according to claim 1, characterized in that: The S5 specifically includes the following steps: S5.1: After the bridge erection machine (1) completes the installation of the prefabricated advanced pier cap beam (4), the bridge erection machine (1) starts to cross the span within 24 hours of waiting for strength; S5.2: The position of the bridge erecting machine (1) when the two carriages return after the bridge erecting machine (1) has completed the erection of the prefabricated advanced pier cap beam (4); S5.3: The fifth leg (15) is supported, and the fourth leg (14) is folded and moved forward 10m to the rear of the third leg (13) for re-support; S5.4: The fourth leg (14) is lifted up, so that the third leg (13) is suspended in the air and moves forward a span, and then re-supported at the next span position; S5.5: The second supporting leg (12) is folded up and moved forward by a span to the top of the cap beam of the next span to support the beam again; S5.6: The fourth outrigger (14) is retracted again and moved forward for 20 m before being supported again; S5.7: The main beam of the bridge erecting machine (1) is sent forward 30m under the drive of the second leg (12), the third leg (13) and the fourth leg (14) anti-support wheels. The bridge erecting machine (1) is moved across the span to the right position at one time, the connection between each leg and the main beam is anchored, and the positions of the front and rear cranes are adjusted so that the bridge erecting machine (1) is able to erect the prefabricated advanced pier columns (2), the prefabricated main span small box beams (3) and the prefabricated advanced pier cap beams (4).

10. The integrated installation process for a fully prefabricated assembled bridge according to any one of claims 1 to 6, characterized in that: Steps S1 to S6 are also monitored throughout, including the following steps: S7.1: Stress / strain monitoring of the bridge erecting machine (1): Through structural analysis and calculation of the bridge erecting machine (1) under various working conditions and on-site construction conditions, the key sections and key rods of the main beam and the first leg (11) are determined, and monitoring points are selected at the key sections and key rods and fiber Bragg grating strain sensors (8) are installed; the stress monitoring points of the main beam are located near the main beam legs and in the middle of each span, and the key load-bearing rods should be selected for stress monitoring of the first leg (11); S7.2: Bridge erecting machine (1) inclination monitoring: the main beam inclination monitoring position is arranged near each span leg, the first leg (11) inclination monitoring position is at its top, and an inclination detector (9) is installed at each inclination monitoring position; S7.3: Safety monitoring uses the following algorithmic process to evaluate the effectiveness of monitoring data: S7.3.1: According to the actual working conditions of data collection, all data are divided into M categories, U = {Q1, Q2…QM}, where M is the working condition type; S7.3.2: Divide all data into N categories according to their own characteristics, U = {P1, P2...PN}; S7.3.3: Set classification error parameters; S7.3.4: For each class Pi, i = 1, 2...N, determine whether it can be included by the majority of any class Qj (j = 1, 2...M); S7.3.5: Merge all Pi, i=1, 2...N that satisfy the majority inclusion relationship, and count the proportion of the number of elements in the set to the total data, which is the evaluation result.

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