Construction technology of full-assembly type marine disaster comprehensive monitoring platform

Abstract

The invention provides a construction technology of a full-assembly type marine disaster comprehensive monitoring platform, and belongs to the technical field of monitoring platform construction, and the construction technology comprises the steps: 1, executing a construction measurement technology for the full-assembly type marine disaster comprehensive monitoring platform; 2, executing a prefabricated part shipping process for the full-assembly type marine disaster comprehensive monitoring platform; and step 3, executing an overwater installation process for the full-assembly type marine disaster comprehensive monitoring platform. Based on the construction engineering practice of a comprehensive marine disaster prevention and control system and aiming at the characteristics of heavy storm, rapid water flow, large component volume and high installation precision requirement of offshore construction of the comprehensive marine disaster monitoring platform, an innovative process covering the whole process of construction measurement, prefabricated component transportation and overwater installation is provided; the key technical problems of prefabrication, transportation and hoisting of open-sea large components are solved, the construction quality and safety of a monitoring platform are guaranteed, and the open-sea engineering construction efficiency is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of monitoring platform construction, and particularly relates to a full-assembled comprehensive monitoring platform for marine disasters. BACKGROUND

[0002] With the intensification of global climate change, the frequency and intensity of marine disasters (such as storm surges, giant waves, tsunamis, etc.) have significantly increased, posing a serious threat to the safety of coastal city infrastructure, the ecological environment, and the lives and property of residents. Many coastal areas are located at the estuaries of rivers, and are affected by river runoff and tidal action, with complex hydrological conditions in the sea area, and typhoons, storm surges and other disasters affecting an average of 3-5 times a year.

[0003] To cope with the risk of marine disasters, it is objectively required to build or upgrade a marine disaster early warning monitoring platform as mentioned in the prior art solution with the patent announcement number "CN220164117U", to realize real-time monitoring and early warning of marine hydrology, meteorology, ecology and other parameters. Such monitoring platforms are mostly built in the open sea (20-50 kilometers from the shore), and need to have wind and wave resistance, corrosion resistance, and long-term stable operation capability, and their construction and construction become the focus and difficulty in the field of marine engineering.

[0004] However, the current marine disaster monitoring platform has the following defects:

[0005] The construction efficiency of the marine disaster monitoring platform is insufficient: the efficiency of the precast site and production line is insufficient, the efficiency of the module vehicle transportation is insufficient, and the efficiency of the water installation window period is insufficient;

[0006] The construction quality of the marine disaster monitoring platform is insufficient: the measurement accuracy is insufficient, the precast quality of the components is insufficient, and the installation connection quality is insufficient;

[0007] The construction safety of the marine disaster monitoring platform is insufficient: the hoisting safety is insufficient, the transportation safety is insufficient, and the disaster resistance is insufficient;

[0008] The economic and environmental benefits are not good. SUMMARY

[0009] To solve the defects in the prior art, the present application provides a full-assembled comprehensive monitoring platform for marine disasters, based on the construction practice of the marine disaster comprehensive prevention and control system, and in view of the characteristics of the marine disaster comprehensive monitoring platform, such as large wind and waves, rapid water flow, large component volume, and high installation precision, an innovative process covering the whole process of construction measurement, precast component transportation, and water installation is proposed, solving the key technical problems of large component precast, transportation, and hoisting in the open sea, ensuring the construction quality and safety of the monitoring platform, and improving the construction efficiency of the open sea project.

[0010] The application uses the following technical solutions.

[0011] A full assembly type ocean disaster comprehensive monitoring platform construction process, comprising:

[0012] Step 1: Perform construction measurement process for full assembly type ocean disaster comprehensive monitoring platform;

[0013] Step 2: Perform prefabricated component delivery process for full assembly type ocean disaster comprehensive monitoring platform;

[0014] Step 3: Perform water installation process for full assembly type ocean disaster comprehensive monitoring platform.

[0015] Preferably, step 1 specifically includes:

[0016] Step 1-1: Construct a measurement reference system;

[0017] Step 1-2: Perform improved construction lofting method;

[0018] Step 1-3: Optimize measurement process flow.

[0019] Preferably, step 1-1 specifically includes:

[0020] Set the plane coordinate and elevation system: adopt the national CGC2000 coordinate system as the plane coordinate reference, and the local elevation system as the elevation reference;

[0021] Control network point transfer and re-measurement: receive the first-level plane control network points provided by the relevant surveying and mapping company, and re-measure according to the requirements of the first-level traverse measurement using the RTK static acquisition method.

[0022] Instrument setting: set the GPS receiver to static mode, set the elevation angle to be greater than or equal to 15 degrees, the sampling interval to be 5-15 seconds, and check the host memory capacity to meet the observation requirements;

[0023] Observation operation: set up a tripod at the control point, strictly center and level, take the instrument height three times, record the instrument number, point name, instrument height and start time; the host searches for stars, the satellite light flashes, and when the recording conditions are met, the epoch data is collected according to the set sampling interval; after the observation is completed, the machine is turned off, the data is transmitted and the office processing is carried out;

[0024] Precision control: the RTK static acquisition precision needs to meet the corresponding requirements of B, C, D and E levels; the GPS network observation basic technical requirements need to meet the corresponding requirements.

[0025] Preferably, step 1-2 specifically includes:

[0026] Application of star station differential mode: arrange a mobile reference station on the traffic ship to provide GPS differential signal and realize the positioning of new platform component installation measurement;

[0027] The layout of different types of components is carried out, including the layout of the caisson installation, the layout of the crash barrier installation, and the layout of the upper monitoring platform installation; the details are as follows:

[0028] Cofferdam installation layout: Measure the actual pile positions after the main platform is driven, import the coordinates into the plan, determine the relationship with the design coordinates of the caisson, set steel limiters and paint marks on the steel pipe piles; after installation, use a handheld GPS to re-measure the corner points of the caisson to ensure that the positional deviation meets the specifications.

[0029] Crash barrier installation layout: Measure the actual pile positions of the crash barrier piles and use them as pre-reserved holes during prefabrication, then directly insert the top of the piles on site;

[0030] Installation layout of the upper monitoring platform: During the construction of the cast-in-place pier, the cup opening of the hidden beam of the upper monitoring platform is reserved based on the corner point of the caisson. Before installation, the bottom elevation of the cup opening is re-measured to ensure that the elevation error is ≤5mm.

[0031] Preferably, step 2 specifically includes:

[0032] Step 2-1: Design the prefabrication site and production line;

[0033] Step 2-2: Assemble and control the in-plant transport module vehicles;

[0034] Steps 2-3: Optimize the component placement process;

[0035] Steps 2-4: Implement the lashing and reinforcement plan for the transport ship.

[0036] Preferably, step 2-1 specifically includes:

[0037] Prefabrication site selection: The designated marine engineering base is selected as the prefabrication site. This prefabrication site has 2 prefabrication production lines, 20 large component prefabrication platforms, 5000t trolleys and supporting shipping wharves, which can meet the prefabrication and shipping needs of 2 concrete cofferdams, 8 anti-collision piers and 2 upper monitoring platforms.

[0038] Improved design of prefabrication platform: Fixed concrete pier foundations are set on both sides of the prefabrication platform for the casing and the upper monitoring platform, and movable jack foundations are set on the other two sides; the jacks are removed after the components reach the designed transport strength.

[0039] Preferably, step 2-2 specifically includes:

[0040] Step 2-2-1: Set up the modular vehicle formation scheme, as follows:

[0041] Concrete caisson transportation: Four 48-axle modular vehicles are used, with a rated load capacity of 2088t;

[0042] The upper monitoring platform is transported using two 32-axle modular vehicles with a rated load capacity of 1392t.

[0043] Crash barrier transportation: 12-axle modular vehicle with a rated load capacity of 528t;

[0044] Step 2-2-2: Set up transportation control measures, as follows:

[0045] Driving speed: The speed of transportation within the factory is strictly controlled within 0.5 km / h;

[0046] Hydraulic system inspection: Before transportation, inspect the hydraulic lines of the modular vehicle to ensure there are no oil leaks before it can be driven; check the tightness of the wheel nuts to ensure they are not loose.

[0047] Alarm handling: When the buzzer or indicator light of the modular vehicle alarms, stop immediately to check for the fault. You can continue driving only after the fault has been eliminated.

[0048] Route planning: Plan the modular vehicle transportation route in advance, clear road obstacles, and ensure smooth traffic.

[0049] Preferably, steps 2-3 specifically include:

[0050] Concrete casing unloading, which includes:

[0051] Vessel selection: An 800t crane vessel will be selected for unloading the barge;

[0052] Timing for unloading: Choose the high tide period when the wind force is less than level 6 and the current speed is less than 0.5 m / s;

[0053] Auxiliary vessels: equipped with one 4,000-horsepower tugboat and one 2,000-horsepower anchor boat;

[0054] Trial lifting procedure: A trial lifting is conducted before unloading to check the lifting weight and the stability of the vessel. After confirming safety, the concrete caisson is unloaded onto the 3000t transport flatbed ship.

[0055] The upper monitoring platform is located on the ground and includes:

[0056] Semi-submersible barge selection: Select a semi-submersible barge and use roll-on / roll-off technology for barge loading;

[0057] berthing procedure:

[0058] Two hours before low tide, the semi-submersible barge was towed by a 5200HP azimuth tugboat to the waters south of the shipping terminal and a temporary anchor chain was dropped.

[0059] During berthing, a 4000HP anchor tug and a 2000HP anchor boat work together, with the anchor boat assisting in casting the bow to the left and right to release anchor or connect to the fixed ground cage.

[0060] With the anchor chain under slight stress, the stern of the semi-submersible barge is tilted towards the dock on the starboard side. The anchor boat delivers steel cables, and dockworkers cooperate to bring the stern cable onto the dock.

[0061] After the stern cable was attached, two anchor boats connected the two anchor cables at the bow of the semi-submersible barge to the fixed ground cage, adjusted the hull to a T-shape and berthed at the departure dock, and added two nylon cables as safety cables. The steel wire ropes of anchor winches No. 1 and No. 2 at the departure dock were attached to the port side of the semi-submersible barge at the mid-forward part and the starboard side at the stern of the barge, respectively. One azimuth tugboat was left to berth against the bow of the semi-submersible barge on the starboard side for standby.

[0062] Roll-on / roll-off operations:

[0063] Lay transition ramps to ensure the modular vehicles are smoothly loaded onto the barge;

[0064] The roll-on / roll-off period for modular vehicles should be selected during high tide when the wind force is less than level 6 and the current speed is relatively low, and the tide level on the monitoring platform should not be less than 2.4m.

[0065] When the modular vehicle is loaded onto the barge, the semi-submersible barge simultaneously adjusts the ballast water load, with an adjustment capacity of 5000 m³ / h, to ensure the stability of the semi-submersible barge's attitude.

[0066] The transshipment process: After the semi-submersible barge leaves the shipping channel of Dayangshan Terminal, the monitoring platform is transferred to a 3000t transport ship by a crane vessel. Temporary fixing measures are adopted during the transshipment process to prevent the components from shifting.

[0067] Crane pier unloading: A 400t crane vessel is used to lift the crash piers from the prefabrication plant's shipping dock to a 3000t transport flatbed vessel. The transport vessel anchors parallel to the dock, and the crane vessel anchors perpendicular to the dock. The unloading time is the same as that of the concrete caissons. Four crash piers can be unloaded in a single trip.

[0068] Preferably, steps 2-4 specifically include:

[0069] Concrete caisson reinforcement: Each concrete caisson uses 10 sets of No. 30 I-beam triangular limit frames as longitudinal and transverse limits, with 3 sets on one side perpendicular to the ship axis to limit the longitudinal and transverse displacement of the caisson.

[0070] Upper monitoring platform reinforcement: Each upper monitoring platform uses 12 sets of No. 30 I-beam triangular limit frames as longitudinal and lateral limit frames, and 4 φ16 steel wire ropes are set for auxiliary binding to prevent the platform from rolling; the support base is fully welded and fixed to the deck of the transport ship; adjustable diagonal bracing steel trusses are set at the four corners and the midpoint of the sides of the building; and steel pipe cross bracing is added inside each floor.

[0071] Anti-collision pier reinforcement: Each anti-collision pier uses 4 sets of No. 30 I-beam triangular limit frames as longitudinal and lateral limits. 4 anti-collision piers are transported in a single trip and evenly distributed on the deck of the transport ship.

[0072] Preferably, step 3 specifically includes:

[0073] Step 3-1: Control installation conditions;

[0074] Step 3-2: Perform the concrete casing installation process;

[0075] Step 3-3: Perform the installation process for the upper monitoring platform;

[0076] Steps 3-4: Perform the installation process for the crash barriers.

[0077] Preferably, step 3-1 specifically includes:

[0078] Meteorological and hydrological conditions: Select a period of light waves with wind force <6, 1-2 hours after high tide, and significant wave height <1m for water installation; obtain the weather forecast for the next 72 hours before construction to ensure that there is no severe weather during the operation window;

[0079] Vessel positioning requirements: After the transport vessel and crane vessel arrive at the construction site, they shall anchor and position themselves according to the direction of the swell and current. The crane vessel's anchor shall press down on the transport vessel's anchor, and the positioning deviation shall be ≤10cm.

[0080] Preferably, step 3-2 specifically includes:

[0081] Lifting equipment design and calculation: The total weight of the concrete caisson is 717t. Eight 450t-13m slings are selected as lifting slings to connect eight caisson lifting lugs and four hooks of the crane vessel.

[0082] Stress calculation: Based on a dynamic load factor of 1.1, the component weight is 717 × 1.1 = 789t; based on a 6-point lifting calculation, the vertical force is 789 ÷ 6 = 132t; the angle between the sling and the lifting lug is 14°, and the sling tension is 132 ÷ cos14° = 136t; the ultimate working load of the U-shaped sling is 450 × 2 = 900t > 136t, and the breaking safety factor is ≥ 6, which meets the requirements;

[0083] The installation steps include:

[0084] Anchoring upon arrival: The transport barge anchors first, the tugboat tows the crane vessel to the site, the anchor boat assists in anchoring, and the crane vessel is positioned in a north-south direction.

[0085] Untying: One hour before high tide, remove the triangular restraints on two of the four sides of the container on the transport ship;

[0086] Lifting and Moving: After the high tide, the crane ship lifts the caisson and the moving ship moves the caisson to the top of the steel pipe piles of the main platform;

[0087] Lowering the caisson: The crane operator observes the ship's position from the transport vessel. After stabilization, the main hook is slowly lowered so that the caisson is about 1m from the top of the steel pipe pile. The ship's position is then moved again to adjust the caisson to a position where it can be fitted onto the main platform, and the lowering continues.

[0088] Positioning and Installation: As the transport vessel approaches the casing, the surveyor and crane operator climb the ladders on both sides of the casing to the top. Based on the positioning of the steel pipe pile's upper steel section limit and paint markings, the bottom steel template of the casing is pre-enlarged and opened. If the template conflicts with the inclined pile, the welder cuts off the conflicting part on site. When the casing is 10cm from the top of the pile, the surveyor uses a handheld GPS to re-measure the two corner points of the casing. After confirming that the deviation is ≤5cm, the casing is completely lowered to the top of the pile.

[0089] Temporary welding restraint: The crane vessel maintains the wire rope taut, and the welder enters the casing to weld eight No. 20 channel steel cross-bracing connecting steel sections between the piles. The steel spreader is then welded to the contact points of the steel pipe piles. Calculated based on the compression of six steel pipe piles, the horizontal component of the force on a single steel pipe pile is 720÷6÷4=30t. The cross-sectional area of ​​the No. 20 channel steel is 28.83cm², the slenderness ratio l / i=240÷7.86=30.5, the stability coefficient ∅=0.916, and the compressive stress is 30×9.8÷(0.916×28.83)=111.3MPa<205MPa, which meets the requirements. After all nine piles are welded to the steel spreader, the crane vessel releases its hook.

[0090] Permanent connection reinforcement: The channel steel is slotted and inserted into the top of the pile. The channel steel, steel spreader, and pile top are welded and fixed. One connecting channel steel is welded to each pile. The nine piles are connected to the casing to form a whole by pre-embedded steel spreader.

[0091] Preferably, step 3-3 specifically includes:

[0092] Specialized lifting equipment design: For the upper monitoring platform, a customized steel structure frame lifting beam lifting equipment is used. A 450t ring sling is set above the frame beam of the lifting equipment, and a 65t polymer ring sling is set below for vertical lifting.

[0093] Stress calculation: Based on a dynamic load factor of 1.1, the component weight is 1015 × 1.1 = 1116.5t; using 13 slings and calculated based on 9-point lifting, the single-point stress is 1116.5 ÷ 9 = 124.06t; the rated lifting capacity of the ring sling is 65 × 2 = 130t > 124.06t, the safety factor is ≥ 6, and the requirements are met;

[0094] The installation steps include:

[0095] Anchoring upon arrival: The transport barge anchors first, then the tugboat tows the 2400t crane vessel to the site, and the anchor boat assists in anchoring. The crane vessel is positioned in a north-south direction.

[0096] Untying: One hour before high tide, remove the triangular limiters and binding steel wire ropes from two of the four sides of the monitoring platform on the transport ship;

[0097] Lifting and Moving: After high tide, the crane vessel lifts the monitoring platform, and the moving vessel moves the platform to above the main platform;

[0098] Lowering the platform: The crane operator and surveyor observe the ship's position from the top of the caisson. After stabilization, the main hook is lowered, so that the platform is lowered to a position about 1m away from the main platform.

[0099] Positioning and installation: Based on the relative position of the hidden beam on the monitoring platform and the reserved slot of the cast-in-place pier, the vessel is moved to ensure that the hidden beam is aligned with the reserved slot, and then lowered to insert the hidden beam into the reserved slot; the vessel is precisely positioned according to the two pre-embedded limiting steel sections and paint markings in the reserved slot, and the position is adjusted multiple times. After the surveyor verifies that the deviation is ≤3cm, the crane vessel is released.

[0100] Concrete pouring: Within 24 hours after installation, C40 micro-expansion concrete will be poured into the reserved groove of the pier to ensure structural integrity. The concrete pouring will be carried out using the underwater tremie pipe method.

[0101] Preferably, steps 3-4 specifically include:

[0102] Lifting equipment selection: Each crash barrier weighs 76t, with 4 lifting points. A 400t crane vessel will be selected, and 6×37S type steel wire ropes with a diameter of 60mm will be used as lifting slings.

[0103] Stress calculation: Assuming uniform stress on 3 lifting lugs, with each wire rope making a 45° angle with the vertical direction, the stress on a single lifting lug wire rope is 76 ÷ (3 × cos45°) = 35.9t; the minimum breaking strength of the wire rope is 35.9 × 6 = 215.4kN < 2154kN, which meets the requirements.

[0104] Installation steps: The installation steps are basically the same as those for concrete caissons, except that the positioning process is simplified; after installation, the caissons are welded and fixed, and C40 concrete is poured into the pre-drilled holes to form a permanent connection.

[0105] The beneficial effects of the present invention are as follows, compared with the prior art:

[0106] (a) Improved construction efficiency

[0107] Prefabrication site and production line: Prefabrication is carried out in a professional marine engineering base, with two production lines operating in parallel, shortening the prefabrication cycle by 30%; the movable jack foundation design reduces the component shipping preparation time by 40%, avoiding the time-consuming problem of traditional pedestal dismantling.

[0108] Modular vehicle transportation: Large-tonnage modular vehicles (48-axle, 32-axle) can transport large components (664.26t box, 1015t monitoring platform) in a single trip. Compared with traditional segmented transportation, the number of transportation trips is reduced by 80%, and the efficiency of in-plant transportation is increased by 50%.

[0109] Utilization of the installation window on water: Through precise analysis of meteorological and hydrological conditions, operations are selected 1-2 hours after high tide. Combined with the wind and wave resistance capabilities of the "Sanhangqi 20" and "Sanhangfengfan" crane vessels, the effective operation time utilization rate is increased to 70% (compared to about 40% for traditional offshore projects), and the installation cycle of a single monitoring platform is shortened to 15 days (compared to about 25 days for traditional processes).

[0110] (ii) Construction quality was guaranteed

[0111] Measurement accuracy control: Using R8 GPS and satellite differential technology, the horizontal accuracy is better than 4cm, the vertical accuracy is better than 8cm, and the component installation position deviation is ≤5cm, which meets the excellent standard of "Waterway Engineering Quality Inspection Standard" (JTS257-2008); a three-level review system (work area, project department, company measurement center) ensures zero error in measurement data.

[0112] Component prefabrication quality: The specialized prefabrication plant adopts standardized production lines, and the concrete pouring adopts a combination of pumping and vibrating rods, with a concrete density of over 98%; the steel bar processing accuracy is controlled within ±2mm, meeting the requirements of the "Code for Acceptance of Construction Quality of Concrete Structures" (GB50204-2015).

[0113] Installation and connection quality: The casing and steel pipe piles are fixed by welding with steel spreader beams and channel steel bracing, and the welding strength meets the tensile strength requirement of 205MPa for Q355B steel; the upper monitoring platform is filled with C40 micro-expansion concrete in the reserved groove, and the bonding strength of the bonding surface reaches 3.5MPa, ensuring the overall stability of the structure.

[0114] (iii) Construction safety was ensured.

[0115] Lifting safety: The safety factor of the lifting equipment is ≥6, far exceeding the standard requirement (standard ≥3.5); the trial lifting process checks for potential hazards in the lifting weight and ship stability, reducing the accident rate of waterborne lifting to 0.

[0116] Transportation safety: The modular vehicle travels at a speed of ≤0.5km / h, the hydraulic system is monitored in real time, and the alarm device provides timely warnings; the transport ship is secured with triangular limit frames and steel wire ropes, and the displacement of components during transportation is ≤2cm, with no risk of overturning.

[0117] Disaster resistance: Crane ships and transport ships are selected with wind and wave resistant models. The "Sanhang Fengfan" can withstand level 10 winds, and the "Sanhang Gong 5" semi-submersible barge has a ballast water adjustment capacity of 6000m³ / h. It can still operate safely under level 6 winds and 1.5m wave height conditions, which improves the disaster resistance of traditional ships by 50%.

[0118] (iv) Excellent economic and environmental benefits

[0119] Economic benefits: Replacing the 2400t crane vessel with an 800t crane vessel reduces the lifting cost per platform by 40%; the modular vehicle roll-on / roll-off process reduces the number of component lifting operations, lowering the component damage rate from 10% to 1% compared to the traditional process, and reducing rework costs by 800,000 yuan; the effective working time is increased, shortening the total project duration by 2 months and saving management costs of 1.2 million yuan.

[0120] Environmental benefits: Centralized prefabrication at the prefabrication plant reduces on-site construction dust (on-site dust concentration ≤0.5mg / m³, meeting Shanghai's environmental protection standards); low-noise equipment is used for construction on water, reducing the impact range on marine life habitats in the construction area to within 50m (compared to about 100m for traditional methods); construction waste is centrally recycled and processed, with a recycling rate of 95%, achieving green construction. Attached Figure Description

[0121] Figure 1 This is a flowchart of the construction process of the fully prefabricated marine disaster integrated monitoring platform in this invention;

[0122] Figure 2 This is the transportation diagram of the concrete casing module vehicle in this invention. Detailed Implementation

[0123] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, other embodiments obtained by those skilled in the art without creative effort are all within the protection scope of this invention.

[0124] like Figure 1 As shown, a construction process for a fully prefabricated marine disaster integrated monitoring platform includes:

[0125] Step 1: Perform construction surveying procedures for the fully prefabricated marine disaster integrated monitoring platform;

[0126] In a preferred but non-limiting embodiment of the present invention, step 1 specifically includes:

[0127] Step 1-1: Construct a measurement benchmark system;

[0128] In a preferred but non-limiting embodiment of the present invention, step 1-1 specifically includes:

[0129] Establish a plane coordinate and elevation system: adopt the national CGC2000 coordinate system as the plane coordinate reference and the local elevation system as the elevation reference to ensure that the measurement data is consistent with the national surveying and mapping standards and lay the foundation for cross-regional construction data sharing;

[0130] Handover and re-measurement of control points: Receive 13 primary horizontal control points (same as primary vertical control points) provided by the relevant surveying and mapping company, and re-measure them according to the requirements of first-order traverse surveying using the RTK static acquisition method.

[0131] Instrument settings: Set the Trimble R8 GPS receiver to static mode, set the elevation angle to ≥15°, the sampling interval to 5-15s, and check that the main unit's memory capacity meets the observation requirements;

[0132] Observation operation: Set up a tripod at the control point, strictly center and level it, measure the instrument height three times (error ≤3mm, take the average value), and record the instrument number, point name, instrument height and start time; the main unit searches for satellites, the satellite light flashes, and after the recording conditions are met, collect historical data according to the set sampling interval; after the observation is completed, turn off the main unit, transmit the data and perform data processing.

[0133] Accuracy control: The accuracy of RTK static acquisition must meet the requirements of B, C, D, and E levels in Table 1; the basic technical specifications for GPS network observation must meet the requirements of Table 2.

[0134] Table 1

[0135]

[0136] Table 2

[0137]

[0138] Steps 1-2: Implement the improved construction layout method;

[0139] In a preferred but non-limiting embodiment of the present invention, steps 1-2 specifically include:

[0140] Application of satellite station differential method: A mobile base station is deployed on the transport ship to provide GPS differential signal to realize the measurement and positioning of the installation of new platform components. The test results show that the horizontal accuracy is better than 4cm and the vertical accuracy is better than 8cm, which meets the positioning requirements of dynamic construction in the open sea.

[0141] The layout of different types of components is carried out, including the layout of the caisson installation, the layout of the crash barrier installation, and the layout of the upper monitoring platform installation; the details are as follows:

[0142] Cofferdam installation layout: Measure the actual pile positions after the main platform is driven, import the coordinates into the plan, determine the relationship with the design coordinates of the caisson, set steel limiters and paint marks on the steel pipe piles; after installation, use a handheld GPS to re-measure the corner points of the caisson to ensure that the positional deviation meets the specifications.

[0143] Crash barrier installation layout: Measure the actual pile positions of the crash barriers and use them as pre-reserved holes during prefabrication. The holes can be directly inserted into the top of the piles on site, reducing on-site adjustment procedures and improving installation efficiency.

[0144] Installation layout of the upper monitoring platform: During the construction of the cast-in-place pier, the cup opening of the hidden beam of the upper monitoring platform is reserved based on the corner point of the caisson. Before installation, the bottom elevation of the cup opening is re-measured to ensure that the elevation error is ≤5mm.

[0145] Steps 1-3: Optimize the measurement process.

[0146] The optimized surveying process is as follows: receiving control points → re-surveying and setting up the control network → submitting to the supervisor and owner for review → establishing a horizontal and vertical control network on-site after the re-survey is approved → three-level verification by the project department, work area, and company surveying center → submitting to the supervisor and owner for review → on-site construction surveying → dynamic monitoring of the construction process → acceptance surveying. This process enables full-process control of surveying work, avoiding rework caused by surveying errors.

[0147] Step 2: Implement the prefabricated component shipping process for the fully prefabricated marine disaster integrated monitoring platform;

[0148] In a preferred but non-limiting embodiment of the present invention, step 2 specifically includes:

[0149] Step 2-1: Design the prefabrication site and production line;

[0150] In a preferred but non-limiting embodiment of the present invention, step 2-1 specifically includes:

[0151] Prefabrication site selection: The designated marine engineering base was selected as the prefabrication site. This prefabrication site has 2 prefabrication production lines, 20 large component prefabrication platforms, 5000t trolleys and supporting shipping wharves, which can meet the prefabrication and shipping needs of 2 concrete cofferdams (664.26t each), 8 crash barriers (76t each), and 2 upper monitoring platforms (heaviest 1015t).

[0152] Improved design of prefabrication platform: Fixed concrete pier foundations are set on both sides of the prefabrication platform for the casing and the upper monitoring platform, and movable jack foundations are set on the other two sides; after the component reaches the design delivery strength (concrete strength ≥ 85% of design strength), the jacks are removed to facilitate the entry and exit of the module vehicle, reduce the number of times the component is lifted, and reduce the risk of component damage.

[0153] Step 2-2: Assemble and control the in-plant transport module vehicles;

[0154] In a preferred but non-limiting embodiment of the present invention, step 2-2 specifically includes:

[0155] Step 2-2-1: Set up the modular vehicle formation scheme, as follows:

[0156] like Figure 2As shown, the concrete caisson transportation uses 4 (6+6) 48-axle modular vehicles with a rated load capacity of 2088t, far exceeding the caisson weight of 664.26t, ensuring transportation safety.

[0157] Upper monitoring platform transportation: Two (6+4+6) 32-axle modular vehicles are used, with a rated load capacity of 1392t, which meets the transportation requirements of the heaviest monitoring platform of 1015t;

[0158] Crash barrier transportation: 12-axle modular vehicle with a rated load capacity of 528t is used to meet the transportation needs of a single 76t crash barrier (4 can be transported in a single trip).

[0159] Step 2-2-2: Set up transportation control measures, as follows:

[0160] Driving speed: The transportation speed within the factory is strictly controlled within 0.5 km / h to avoid the components shaking due to emergency braking;

[0161] Hydraulic system inspection: Before transportation, inspect the hydraulic lines of the modular vehicle to ensure there are no oil leaks before it can be driven; check the tightness of the wheel nuts to ensure they are not loose.

[0162] Alarm handling: When the buzzer or indicator light of the modular vehicle alarms, stop immediately to check for the fault. You can continue driving only after the fault has been eliminated.

[0163] Route planning: Plan the modular vehicle transportation route in advance, clear road obstacles, and ensure smooth traffic.

[0164] Steps 2-3: Optimize the component placement process;

[0165] In a preferred but non-limiting embodiment of the present invention, steps 2-3 specifically include:

[0166] Concrete casing unloading, which includes:

[0167] Vessel selection: The 800t crane vessel "Sanhangqi 20" (80m in length, 30m in width, 5.8m in depth, 3.6m in draft, and 56.2m in water surface lifting height of the main hook) will be selected for barge unloading to replace the original 2400t crane vessel, thereby reducing construction costs;

[0168] Timing of barge placement: Select the high tide period when the wind force is less than level 6 and the current speed is less than 0.5m / s to reduce the impact of wind and waves on the accuracy of barge placement;

[0169] Auxiliary vessels: Equipped with one 4,000-horsepower tugboat and one 2,000-horsepower anchor boat to assist the "Sanhangqi 20" in berthing and departure from the dock and ensure accurate vessel positioning;

[0170] Trial lifting procedure: A trial lifting is conducted before unloading to check the lifting weight and the stability of the vessel. After confirming safety, the concrete caisson is unloaded onto the 3000t transport flatbed ship.

[0171] The upper monitoring platform is located on the ground and includes:

[0172] Semi-submersible barge selection: Select the "Sanhanggong 5" semi-submersible barge (length 100m, beam 40m, depth 7m, draft 3.8m when empty, draft 5m when fully loaded, carrying capacity 10,000t under working conditions, ballast water adjustment capacity 6,000m³ / h), and use roll-on / roll-off process for barge unloading;

[0173] berthing procedure:

[0174] Two hours before low tide, the semi-submersible barge was towed by a 5200HP azimuth tugboat to the waters south of the shipping pier and a temporary anchor chain was dropped (location: 50m west of the south edge of the pier).

[0175] During berthing, a 4000HP anchor tug and a 2000HP anchor boat work together, with the anchor boat assisting in casting the bow to the left and right to release anchor or connect to the fixed ground cage.

[0176] With the anchor chain under slight stress, the stern of the semi-submersible barge is tilted towards the dock on the starboard side. The anchor boat delivers steel cables, and dockworkers cooperate to bring the stern cable onto the dock.

[0177] After the stern line was secured, two anchor boats connected the two bow anchor lines of the semi-submersible barge to the fixed ground cage, adjusted the hull to a T-shape to berth at the departure dock (bow facing west towards Datiebing Island, stern facing Dayangshan Island), and added two nylon ropes as safety lines. The steel wire ropes of anchor winches No. 1 and No. 2 at the departure dock were attached to the port side mid-forward and starboard side stern bollards of the semi-submersible barge, respectively. One azimuth tugboat was left to berth alongside the starboard bow of the semi-submersible barge (the entire berthing operation took about 3 hours).

[0178] Roll-on / roll-off operations:

[0179] Lay transition ramps to ensure the modular vehicles are smoothly loaded onto the barge;

[0180] The roll-on / roll-off period for modular vehicles should be selected during high tide when the wind force is less than level 6 and the current speed is relatively low, and the tide level on the monitoring platform should not be less than 2.4m.

[0181] When the modular vehicle is loaded onto the barge, the semi-submersible barge simultaneously adjusts the ballast water load with a capacity of 5000 m³ / h to ensure the stability of the semi-submersible barge's attitude. Taking the upper monitoring platform (1015t) as an example, the total amount of water ballasted during loading is 2120 m³, the ballast time is ≥26 min, the total loading time of the modular vehicle is controlled within 1 hour, and the average travel speed is 1 m / min.

[0182] The transshipment process: After the semi-submersible barge leaves the shipping channel of Dayangshan Terminal, the monitoring platform is transferred to a 3000t transport ship by a crane vessel. Temporary fixing measures are adopted during the transshipment process to prevent the components from shifting.

[0183] Crane pier unloading: A 400t crane vessel is used to lift the crash piers from the prefabrication plant's shipping dock to a 3000t transport flatbed vessel. The transport vessel anchors parallel to the dock, and the crane vessel anchors perpendicular to the dock. The unloading time is the same as that of the concrete caissons. Four crash piers can be unloaded in a single trip.

[0184] Steps 2-4: Implement the lashing and reinforcement plan for the transport ship.

[0185] In a preferred but non-limiting embodiment of the present invention, steps 2-4 specifically include:

[0186] Concrete caisson reinforcement: Each concrete caisson uses 10 sets of No. 30 I-beam triangular limit frames as longitudinal and transverse limits, with 3 sets on one side perpendicular to the ship axis to limit the longitudinal and transverse displacement of the caisson and ensure the stability of the caisson during transportation.

[0187] Upper monitoring platform reinforcement: Each upper monitoring platform uses 12 sets of No. 30 I-beam triangular limit frames as longitudinal and lateral limits, and is also equipped with 4 φ16 steel wire ropes for auxiliary binding to prevent the platform from rolling; the support base is fully welded and fixed to the deck of the transport ship; adjustable diagonal steel trusses are installed at the four corners and midpoints of the building (the upper end is connected to the building structure beam, and the lower end is welded to the deck strong structure); steel pipe cross braces are added inside each floor (connecting to the diagonal load-bearing walls) to enhance the overall torsional stiffness and prevent deformation and cracking;

[0188] Anti-collision pier reinforcement: Each anti-collision pier uses 4 sets of No. 30 I-beam triangular limit frames as longitudinal and lateral limits. 4 anti-collision piers are transported in a single trip and evenly distributed on the deck of the transport ship to ensure force balance.

[0189] Step 3: Perform the on-water installation process for the fully prefabricated marine disaster integrated monitoring platform.

[0190] In a preferred but non-limiting embodiment of the present invention, step 3 specifically includes:

[0191] Step 3-1: Control installation conditions;

[0192] In a preferred but non-limiting embodiment of the present invention, step 3-1 specifically includes:

[0193] Meteorological and hydrological conditions: Select a period of light waves with wind force <6, 1-2 hours after high tide, and significant wave height <1m for water installation to avoid wind, waves and swells affecting installation accuracy; obtain the weather forecast for the next 72 hours before construction to ensure that there is no severe weather during the operation window;

[0194] Vessel positioning requirements: After the transport vessel and crane vessel arrive at the construction site, they shall anchor and position themselves according to the direction of the swell and current. The crane vessel's anchor shall press down on the transport vessel's anchor to ensure the stability of the vessels. The positioning deviation shall be ≤10cm.

[0195] Step 3-2: Perform the concrete casing installation process;

[0196] In a preferred but non-limiting embodiment of the present invention, step 3-2 specifically includes:

[0197] Lifting equipment design and calculation: The total weight of the concrete caisson is 717t (including 664.26t of caisson, 21.83t of steel spreader beam, 7.3t of pre-embedded channel steel for the reverse lifting system, 19t of steel plate, and 4t of 8 lifting slings). Eight 450t-13m (working length) lifting slings are selected as lifting equipment to connect eight caisson lifting lugs and four hooks of the crane vessel.

[0198] Stress calculation: Based on a dynamic load factor of 1.1, the component weight is 717 × 1.1 = 789t; based on a 6-point lifting calculation, the vertical force is 789 ÷ 6 = 132t; the angle between the sling and the lifting lug is 14°, and the sling tension is 132 ÷ cos14° = 136t; the ultimate working load of the U-shaped sling is 450 × 2 = 900t > 136t, and the breaking safety factor is ≥ 6, which meets the requirements;

[0199] The installation steps include:

[0200] Anchoring upon arrival: The transport barge anchors first, the tugboat tows the crane vessel "Sanhangqi 20" to the site, the anchor boat assists in anchoring, and the crane vessel is positioned in a north-south direction.

[0201] Untying: One hour before high tide, remove the triangular restraints on two of the four sides of the container on the transport ship to ensure that the container can be lifted smoothly;

[0202] Lifting and Moving: After the high tide, the crane vessel slowly lifts the caisson and the moving vessel moves the caisson to the top of the steel pipe piles on the main platform;

[0203] Lowering the caisson: The crane operator observes the ship's position from the transport vessel. After stabilization, the main hook is slowly lowered so that the caisson is about 1m from the top of the steel pipe pile. The ship's position is then moved again to adjust the caisson to a position where it can be fitted onto the main platform, and the lowering continues.

[0204] Positioning and Installation: As the transport vessel approaches the casing, the surveyor and crane operator climb the ladders on both sides of the casing to the top. Based on the steel pipe pile's upper limit and paint markings, the bottom steel template of the casing is pre-enlarged (ensuring that 9 holes can accommodate 9 piles). If the template conflicts with the inclined pile, the welder cuts off the conflicting parts on-site. When the casing is 10cm from the top of the pile, the surveyor uses a handheld GPS to re-measure the two corner points of the casing. After confirming that the deviation is ≤5cm, the casing is completely lowered to the top of the pile.

[0205] Temporary welding restraint: The crane vessel maintains the wire rope taut, and the welder enters the casing to weld eight No. 20 channel steel cross-bracing connecting steel sections between the piles. The steel spreader is then welded to the contact points of the steel pipe piles. Calculated based on the compression of six steel pipe piles, the horizontal component of the force on a single steel pipe pile is 720÷6÷4=30t. The cross-sectional area of ​​the No. 20 channel steel is 28.83cm², the slenderness ratio l / i=240÷7.86=30.5, the stability coefficient ∅=0.916, and the compressive stress is 30×9.8÷(0.916×28.83)=111.3MPa<205MPa, which meets the requirements. After all nine piles are welded to the steel spreader, the crane vessel releases its hook.

[0206] Permanent connection reinforcement: The channel steel is slotted and inserted into the top of the pile. The channel steel, steel spreader, and pile top are welded and fixed. One connecting channel steel is welded to each pile. The nine piles are connected to the casing to form a whole by pre-embedded steel spreader.

[0207] Step 3-3: Perform the installation process for the upper monitoring platform;

[0208] In a preferred but non-limiting embodiment of the present invention, step 3-3 specifically includes:

[0209] Specialized lifting equipment design: For the upper monitoring platform (heaviest 1015t), a customized steel structure frame lifting beam lifting equipment is used. A 450t ring sling is set above the frame beam of the lifting equipment, and a 65t polymer ring sling is set below (with 150t shackles) for vertical lifting (2 inclined lifting beams).

[0210] Stress calculation: Based on a dynamic load factor of 1.1, the component weight is 1015 × 1.1 = 1116.5t; using 13 slings and calculated based on 9-point lifting, the single-point stress is 1116.5 ÷ 9 = 124.06t; the rated lifting capacity of the ring sling is 65 × 2 = 130t > 124.06t, the safety factor is ≥ 6, and the requirements are met;

[0211] The installation steps include:

[0212] Anchoring upon arrival: The transport barge anchors first, and the tugboat tows the 2400t crane vessel "Sanhang Fengfan" (96m long, 40.5m wide, 7.8m deep, 4.5m draft, and 86.5m lifting height of the main hook on the water surface) to the site. The anchor boat assists in anchoring, and the crane vessel is positioned in a north-south direction.

[0213] Untying: One hour before high tide, remove the triangular limiters and binding steel wire ropes from two of the four sides of the monitoring platform on the transport ship to ensure that the platform can be lifted smoothly;

[0214] Lifting and Moving: After high tide, the crane vessel slowly lifts the monitoring platform, and the moving vessel moves the platform to above the main platform;

[0215] Lowering the platform: The crane operator and surveyor observe the ship's position from the top of the gantry. After stabilization, the main hook is slowly lowered so that the platform is about 1m away from the main platform.

[0216] Positioning and installation: Based on the relative position of the hidden beam on the monitoring platform and the reserved slot of the cast-in-place pier, the vessel is moved to ensure that the hidden beam is aligned with the reserved slot, and then slowly lowered to insert the hidden beam into the reserved slot; the vessel is precisely positioned according to the two pre-embedded limiting steel sections and paint markings in the reserved slot, and the position is adjusted multiple times. After the surveyor verifies that the deviation is ≤3cm, the crane vessel is released.

[0217] Concrete pouring: Within 24 hours after installation, C40 micro-expansion concrete will be poured into the reserved groove of the pier to ensure structural integrity. The concrete pouring will be carried out using the underwater tremie method to prevent seawater from affecting the quality of the concrete.

[0218] Steps 3-4: Perform the installation process for the crash barriers.

[0219] In a preferred but non-limiting embodiment of the present invention, steps 3-4 specifically include:

[0220] Lifting equipment selection: Each crash barrier weighs 76t, with 4 lifting points. A 400t crane vessel is selected, and 6×37S type steel wire rope with a diameter of 60mm (minimum breaking strength 2154kN, safety factor 6) is used as the lifting equipment.

[0221] Stress calculation: Assuming uniform stress on 3 lifting lugs, with each wire rope making a 45° angle with the vertical direction, the stress on a single lifting lug wire rope is 76 ÷ (3 × cos45°) = 35.9t; the minimum breaking strength of the wire rope is 35.9 × 6 = 215.4kN < 2154kN, which meets the requirements.

[0222] Installation steps: The installation steps are basically the same as those for concrete casing, except that the positioning process is simplified (because the pre-drilled holes of the crash barrier match the actual pile position, it can be directly inserted into the top of the pile on site); after installation, it is welded and fixed, and C40 concrete is poured into the pre-drilled hole to form a permanent connection.

[0223] The beneficial effects of the present invention are as follows, compared with the prior art:

[0224] (a) Improved construction efficiency

[0225] Prefabrication site and production line: Prefabrication is carried out in a professional marine engineering base, with two production lines operating in parallel, shortening the prefabrication cycle by 30%; the movable jack foundation design reduces the component shipping preparation time by 40%, avoiding the time-consuming problem of traditional pedestal dismantling.

[0226] Modular vehicle transportation: Large-tonnage modular vehicles (48-axle, 32-axle) can transport large components (664.26t box, 1015t monitoring platform) in a single trip. Compared with traditional segmented transportation, the number of transportation trips is reduced by 80%, and the efficiency of in-plant transportation is increased by 50%.

[0227] Utilization of the installation window on water: Through precise analysis of meteorological and hydrological conditions, operations are selected 1-2 hours after high tide. Combined with the wind and wave resistance capabilities of the "Sanhangqi 20" and "Sanhangfengfan" crane vessels, the effective operation time utilization rate is increased to 70% (compared to about 40% for traditional offshore projects), and the installation cycle of a single monitoring platform is shortened to 15 days (compared to about 25 days for traditional processes).

[0228] (ii) Construction quality was guaranteed

[0229] Measurement accuracy control: Using R8 GPS and satellite differential technology, the horizontal accuracy is better than 4cm, the vertical accuracy is better than 8cm, and the component installation position deviation is ≤5cm, which meets the excellent standard of "Waterway Engineering Quality Inspection Standard" (JTS257-2008); a three-level review system (work area, project department, company measurement center) ensures zero error in measurement data.

[0230] Component prefabrication quality: The specialized prefabrication plant adopts standardized production lines, and the concrete pouring adopts a combination of pumping and vibrating rods, with a concrete density of over 98%; the steel bar processing accuracy is controlled within ±2mm, meeting the requirements of the "Code for Acceptance of Construction Quality of Concrete Structures" (GB50204-2015).

[0231] Installation and connection quality: The casing and steel pipe piles are fixed by welding with steel spreader beams and channel steel bracing, and the welding strength meets the tensile strength requirement of 205MPa for Q355B steel; the upper monitoring platform is filled with C40 micro-expansion concrete in the reserved groove, and the bonding strength of the bonding surface reaches 3.5MPa, ensuring the overall stability of the structure.

[0232] (iii) Construction safety was ensured.

[0233] Lifting safety: The safety factor of the lifting equipment is ≥6, far exceeding the standard requirement (standard ≥3.5); the trial lifting process checks for potential hazards in the lifting weight and ship stability, reducing the accident rate of waterborne lifting to 0.

[0234] Transportation safety: The modular vehicle travels at a speed of ≤0.5km / h, the hydraulic system is monitored in real time, and the alarm device provides timely warnings; the transport ship is secured with triangular limit frames and steel wire ropes, and the displacement of components during transportation is ≤2cm, with no risk of overturning.

[0235] Disaster resistance: Crane ships and transport ships are selected with wind and wave resistant models. The "Sanhang Fengfan" can withstand level 10 winds, and the "Sanhang Gong 5" semi-submersible barge has a ballast water adjustment capacity of 6000m³ / h. It can still operate safely under level 6 winds and 1.5m wave height conditions, which improves the disaster resistance of traditional ships by 50%.

[0236] (iv) Excellent economic and environmental benefits

[0237] Economic benefits: Replacing the 2400t crane vessel with an 800t crane vessel reduces the lifting cost per platform by 40%; the modular vehicle roll-on / roll-off process reduces the number of component lifting operations, lowering the component damage rate from 10% to 1% compared to the traditional process, and reducing rework costs by 800,000 yuan; the effective working time is increased, shortening the total project duration by 2 months and saving management costs of 1.2 million yuan.

[0238] Environmental benefits: Centralized prefabrication at the prefabrication plant reduces on-site construction dust (on-site dust concentration ≤0.5mg / m³, meeting Shanghai's environmental protection standards); low-noise equipment is used for construction on water, reducing the impact range on marine life habitats in the construction area to within 50m (compared to about 100m for traditional methods); construction waste is centrally recycled and processed, with a recycling rate of 95%, achieving green construction.

[0239] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention without departing from the spirit and scope of the present invention. Any modifications or equivalent substitutions should be covered within the scope of protection of the claims of the present invention.

Claims

1. A construction technology for a fully prefabricated marine disaster integrated monitoring platform, characterized in that, include: Step 1: Perform construction surveying procedures for the fully prefabricated marine disaster integrated monitoring platform; Step 2: Implement the prefabricated component shipping process for the fully prefabricated marine disaster integrated monitoring platform; Step 3: Perform the on-water installation process for the fully prefabricated marine disaster integrated monitoring platform.

2. The construction technology of the fully prefabricated marine disaster integrated monitoring platform according to claim 1, characterized in that, Step 1 specifically includes: Step 1-1: Construct a measurement benchmark system; Steps 1-2: Implement the improved construction layout method; Steps 1-3: Optimize the measurement process.

3. The construction technology of the fully prefabricated marine disaster integrated monitoring platform according to claim 2, characterized in that, Step 1-1 specifically includes: Establish the plane coordinate and elevation system: The national CGC2000 coordinate system is adopted as the plane coordinate reference, and the local elevation system is adopted as the elevation reference; Control point handover and re-survey: Receive the primary horizontal control points provided by the relevant surveying company and re-survey them according to the requirements of first-order traverse surveying using the RTK static acquisition method. Instrument settings: Set the GPS receiver to static mode, set the elevation angle to ≥15°, the sampling interval to 5-15s, and check that the host memory capacity meets the observation requirements; Observation operation: Set up the tripod at the control point, strictly center and level it, measure the instrument height three times, and record the instrument number, point name, instrument height and start time; the main unit searches for satellites, the satellite light flashes, and after the recording conditions are met, collect historical data according to the set sampling interval; after the observation is completed, turn off the main unit, transmit the data and perform data processing. Accuracy control: RTK static acquisition accuracy must meet the corresponding requirements of level B, C, D, or E; GPS network observation basic technical specifications must meet the corresponding requirements; Steps 1-2 specifically include: Application of satellite differential method: Deploy mobile base stations on transport ships to provide GPS differential signals and realize measurement and positioning for the installation of components on newly built platforms; The layout of different types of components is carried out, including the layout of the caisson installation, the layout of the crash barrier installation, and the layout of the upper monitoring platform installation; the details are as follows: Cofferdam installation layout: Measure the actual pile positions after the main platform is driven, import the coordinates into the plan, determine the relationship with the design coordinates of the caisson, set steel limiters and paint marks on the steel pipe piles; after installation, use a handheld GPS to re-measure the corner points of the caisson to ensure that the positional deviation meets the specifications. Crash barrier installation layout: Measure the actual pile positions of the crash barrier piles and use them as pre-reserved holes during prefabrication, then directly insert the top of the piles on site; Installation layout of the upper monitoring platform: During the construction of the cast-in-place pier, the cup opening of the hidden beam of the upper monitoring platform is reserved based on the corner point of the caisson. Before installation, the bottom elevation of the cup opening is re-measured to ensure that the elevation error is ≤5mm.

4. The construction technology of the fully prefabricated marine disaster integrated monitoring platform according to claim 3, characterized in that, Step 2 specifically includes: Step 2-1: Design the prefabrication site and production line; Step 2-2: Assemble and control the in-plant transport module vehicles; Steps 2-3: Optimize the component placement process; Steps 2-4: Implement the lashing and reinforcement plan for the transport ship.

5. The construction technology of the fully prefabricated marine disaster integrated monitoring platform according to claim 4, characterized in that, Step 2-1 specifically includes: Prefabrication site selection: The designated marine engineering base is selected as the prefabrication site. This prefabrication site has 2 prefabrication production lines, 20 large component prefabrication platforms, 5000t trolleys and supporting shipping wharves, which can meet the prefabrication and shipping needs of 2 concrete cofferdams, 8 anti-collision piers and 2 upper monitoring platforms. Improved design of prefabrication platform: Fixed concrete pier foundations are set on both sides of the prefabrication platform for the casing and the upper monitoring platform, and movable jack foundations are set on the other two sides; the jacks are removed after the components reach the design transport strength. Step 2-2 specifically includes: Step 2-2-1: Set up the modular vehicle formation scheme, as follows: Concrete caisson transportation: Four 48-axle modular vehicles are used, with a rated load capacity of 2088t; The upper monitoring platform is transported using two 32-axle modular vehicles with a rated load capacity of 1392t. Crash barrier transportation: 12-axle modular vehicle with a rated load capacity of 528t; Step 2-2-2: Set up transportation control measures, as follows: Driving speed: The speed of transportation within the factory is strictly controlled within 0.5 km / h; Hydraulic system inspection: Before transportation, inspect the hydraulic lines of the modular vehicle to ensure there are no oil leaks before it can be driven; check the tightness of the wheel nuts to ensure they are not loose. Alarm handling: When the buzzer or indicator light of the modular vehicle alarms, stop immediately to check for the fault. You can continue driving only after the fault has been eliminated. Route planning: Plan the modular vehicle transportation route in advance, clear road obstacles, and ensure smooth traffic.

6. The construction technology of the fully prefabricated marine disaster integrated monitoring platform according to claim 5, characterized in that, Steps 2-3 specifically include: Concrete casing unloading, which includes: Vessel selection: An 800t crane vessel will be selected for unloading the barge; Timing for unloading: Choose the high tide period when the wind force is less than level 6 and the current speed is less than 0.5 m / s; Auxiliary vessels: equipped with one 4,000-horsepower tugboat and one 2,000-horsepower anchor boat; Trial lifting procedure: A trial lifting is conducted before unloading to check the lifting weight and the stability of the vessel. After confirming safety, the concrete caisson is unloaded onto the 3000t transport flatbed ship. The upper monitoring platform is located on the ground and includes: Semi-submersible barge selection: Select a semi-submersible barge and use roll-on / roll-off technology for barge loading; berthing procedure: Two hours before low tide, the semi-submersible barge was towed by a 5200HP azimuth tugboat to the waters south of the shipping terminal and a temporary anchor chain was dropped. During berthing, a 4000HP anchor tug and a 2000HP anchor boat work together, with the anchor boat assisting in casting the bow to the left and right to release anchor or connect to the fixed ground cage. With the anchor chain under slight stress, the stern of the semi-submersible barge is tilted towards the dock on the starboard side. The anchor boat delivers steel cables, and dockworkers cooperate to bring the stern cable onto the dock. After the stern cable was attached, two anchor boats connected the two anchor cables at the bow of the semi-submersible barge to the fixed ground cage, adjusted the hull to a T-shape and berthed at the departure dock, and added two nylon cables as safety cables. The steel wire ropes of anchor winches No. 1 and No. 2 at the departure dock were attached to the port side of the semi-submersible barge at the mid-forward part and the starboard side at the stern of the barge, respectively. One azimuth tugboat was left to berth against the bow of the semi-submersible barge on the starboard side for standby. Roll-on / roll-off operations: Lay transition ramps to ensure the modular vehicles are smoothly loaded onto the barge; The roll-on / roll-off period for modular vehicles should be selected during high tide when the wind force is less than level 6 and the current speed is relatively low, and the tide level on the monitoring platform should not be less than 2.4m. When the modular vehicle is loaded onto the barge, the semi-submersible barge simultaneously adjusts the ballast water load, with an adjustment capacity of 5000 m³ / h, to ensure the stability of the semi-submersible barge's attitude. The transshipment process: After the semi-submersible barge leaves the shipping channel of Dayangshan Terminal, the monitoring platform is transferred to a 3000t transport ship by a crane vessel. Temporary fixing measures are adopted during the transshipment process to prevent the components from shifting. Crane pier unloading: A 400t crane ship is used to lift the crash piers from the prefabrication plant's shipping dock to a 3000t transport flatbed ship. The transport ship anchors parallel to the dock, and the crane ship anchors perpendicular to the dock. The unloading time is the same as the concrete caisson. Four crash piers can be unloaded in a single trip. Steps 2-4 specifically include: Concrete caisson reinforcement: Each concrete caisson uses 10 sets of No. 30 I-beam triangular limit frames as longitudinal and transverse limits, with 3 sets on one side perpendicular to the ship axis to limit the longitudinal and transverse displacement of the caisson. Upper monitoring platform reinforcement: Each upper monitoring platform uses 12 sets of No. 30 I-beam triangular limit frames as longitudinal and lateral limit frames, and 4 φ16 steel wire ropes are set for auxiliary binding to prevent the platform from rolling; the support base is fully welded and fixed to the deck of the transport ship; adjustable diagonal bracing steel trusses are set at the four corners and the midpoint of the sides of the building; and steel pipe cross bracing is added inside each floor. Anti-collision pier reinforcement: Each anti-collision pier uses 4 sets of No. 30 I-beam triangular limit frames as longitudinal and lateral limits. 4 anti-collision piers are transported in a single trip and evenly distributed on the deck of the transport ship.

7. The construction technology of the fully prefabricated marine disaster integrated monitoring platform according to claim 6, characterized in that, Step 3 specifically includes: Step 3-1: Control installation conditions; Step 3-2: Perform the concrete casing installation process; Step 3-3: Perform the installation process for the upper monitoring platform; Steps 3-4: Perform the installation process for the crash barriers.

8. The construction technology of the fully prefabricated marine disaster integrated monitoring platform according to claim 7, characterized in that, Step 3-1 specifically includes: Meteorological and hydrological conditions: Select a period of light waves with wind force <6, 1-2 hours after high tide, and significant wave height <1m for water installation; obtain the weather forecast for the next 72 hours before construction to ensure that there is no severe weather during the operation window; Vessel positioning requirements: After the transport vessel and crane vessel arrive at the construction site, they shall anchor and position themselves according to the direction of the swell and current. The crane vessel's anchor shall press down on the transport vessel's anchor, and the positioning deviation shall be ≤10cm.

9. The construction technology of the fully prefabricated marine disaster integrated monitoring platform according to claim 8, characterized in that, Step 3-2 specifically includes: Lifting equipment design and calculation: The total weight of the concrete caisson is 717t. Eight 450t-13m slings are selected as lifting slings to connect eight caisson lifting lugs and four hooks of the crane vessel. Stress calculation: Based on a dynamic load factor of 1.1, the component weight is 717 × 1.1 = 789t; based on a 6-point lifting calculation, the vertical force is 789 ÷ 6 = 132t; the angle between the sling and the lifting lug is 14°, and the sling tension is 132 ÷ cos14° = 136t; the ultimate working load of the U-shaped sling is 450 × 2 = 900t > 136t, and the breaking safety factor is ≥ 6, which meets the requirements; The installation steps include: Anchoring upon arrival: The transport barge anchors first, the tugboat tows the crane vessel to the site, the anchor boat assists in anchoring, and the crane vessel is positioned in a north-south direction. Untying: One hour before high tide, remove the triangular restraints on two of the four sides of the container on the transport ship; Lifting and Moving: After the high tide, the crane ship lifts the caisson and the moving ship moves the caisson to the top of the steel pipe piles of the main platform; Lowering the caisson: The crane operator observes the ship's position from the transport vessel. After stabilization, the main hook is slowly lowered so that the caisson is about 1m from the top of the steel pipe pile. The ship's position is then moved again to adjust the caisson to a position where it can be fitted onto the main platform, and the lowering continues. Positioning and Installation: As the transport vessel approaches the casing, the surveyor and crane operator climb the ladders on both sides of the casing to the top. Based on the positioning of the steel pipe pile's upper steel section limit and paint markings, the bottom steel template of the casing is pre-enlarged and opened. If the template conflicts with the inclined pile, the welder cuts off the conflicting part on site. When the casing is 10cm from the top of the pile, the surveyor uses a handheld GPS to re-measure the two corner points of the casing. After confirming that the deviation is ≤5cm, the casing is completely lowered to the top of the pile. Temporary welding restraint: The crane vessel maintains the wire rope taut, and the welder enters the casing to weld eight No. 20 channel steel cross-bracing connecting steel sections between the piles. The steel spreader is then welded to the contact points of the steel pipe piles. Calculated based on the compression of six steel pipe piles, the horizontal component of the force on a single steel pipe pile is 720÷6÷4=30t. The cross-sectional area of ​​the No. 20 channel steel is 28.83cm², the slenderness ratio l / i=240÷7.86=30.5, the stability coefficient ∅=0.916, and the compressive stress is 30×9.8÷(0.916×28.83)=111.3MPa<205MPa, which meets the requirements. After all nine piles are welded to the steel spreader, the crane vessel releases its hook. Permanent connection reinforcement: The channel steel is slotted and inserted into the top of the pile. The channel steel, steel spreader, and pile top are welded and fixed. One connecting channel steel is welded to each pile. The nine piles are connected to the casing to form a whole by pre-embedded steel spreader.

10. The construction technology of the fully prefabricated marine disaster integrated monitoring platform according to claim 9, characterized in that, Step 3-3 specifically includes: Specialized lifting equipment design: For the upper monitoring platform, a customized steel structure frame lifting beam lifting equipment is used. A 450t ring sling is set above the frame beam of the lifting equipment, and a 65t polymer ring sling is set below for vertical lifting. Stress calculation: Based on a dynamic load factor of 1.1, the component weight is 1015 × 1.1 = 1116.5t; using 13 slings and calculated based on 9-point lifting, the single-point stress is 1116.5 ÷ 9 = 124.06t; the rated lifting capacity of the ring sling is 65 × 2 = 130t > 124.06t, the safety factor is ≥ 6, and the requirements are met; The installation steps include: Anchoring upon arrival: The transport barge anchors first, then the tugboat tows the 2400t crane vessel to the site, and the anchor boat assists in anchoring. The crane vessel is positioned in a north-south direction. Untying: One hour before high tide, remove the triangular limiters and binding steel wire ropes from two of the four sides of the monitoring platform on the transport ship; Lifting and Moving: After high tide, the crane vessel lifts the monitoring platform, and the moving vessel moves the platform to above the main platform; Lowering the platform: The crane operator and surveyor observe the ship's position from the top of the caisson. After stabilization, the main hook is lowered, so that the platform is lowered to a position about 1m away from the main platform. Positioning and installation: Based on the relative position of the hidden beam on the monitoring platform and the reserved slot of the cast-in-place pier, the vessel is moved to ensure that the hidden beam is aligned with the reserved slot, and then lowered to insert the hidden beam into the reserved slot; the vessel is precisely positioned according to the two pre-embedded limiting steel sections and paint markings in the reserved slot, and the position is adjusted multiple times. After the surveyor verifies that the deviation is ≤3cm, the crane vessel is released. Concrete pouring: Within 24 hours after installation, C40 micro-expansion concrete will be poured into the reserved groove of the pier to ensure structural integrity. The concrete pouring will be carried out using the underwater tremie pipe method. Steps 3-4 specifically include: Lifting equipment selection: Each crash barrier weighs 76t, with 4 lifting points. A 400t crane vessel will be selected, and 6×37S type steel wire ropes with a diameter of 60mm will be used as lifting slings. Stress calculation: Assuming uniform stress on 3 lifting lugs, with each wire rope making a 45° angle with the vertical direction, the stress on a single lifting lug wire rope is 76 ÷ (3 × cos45°) = 35.9t; the minimum breaking strength of the wire rope is 35.9 × 6 = 215.4kN < 2154kN, which meets the requirements. Installation steps: The installation steps are basically the same as those for concrete caissons, except that the positioning process is simplified; after installation, the caissons are welded and fixed, and C40 concrete is poured into the pre-drilled holes to form a permanent connection.

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