A method for testing the sealing performance of steel caisson structures

Abstract

This invention discloses a method for inspecting the sealing performance of a steel caisson structure, comprising: Step 1: Dividing the steel caisson's compartments into several mutually sealed zones; the compartments within the same zone are connected at the bottom; each zone has at least one water-filled compartment, and the remaining compartments are equipped with sealing plates; Step 2: Installing a water-filling and drainage system and a water level monitoring system; Step 3: Filling the dock with water to the buoyancy-aiding height and checking the sealing performance of the buoyancy-aiding plates; Step 4: Filling the first batch of water-filled compartments with water to the first height and checking the sealing performance of the sealing plates; Step 5: Filling the first batch of compartments with water to the second height and checking the structural sealing performance of this batch of compartments; Step 6: Referring to Steps 4 and 5, conducting sealing performance inspections on the remaining batches of compartments; Step 7: After the inspection is completed, draining the water from all compartments. This method, employing a batch-by-batch water-filling inspection approach into the caisson's steel shell, achieves efficient, convenient, comprehensive, accurate, safe, and reliable inspection results.

Description

Technical Field

[0001] This invention relates to the field of caisson construction technology, and in particular to a method for testing the sealing performance of steel caisson structures. Background Technology

[0002] The steel shell of the caisson is typically manufactured and assembled in a dry dock. After assembly, a sealing test is required. Only after passing the test can the subsequent processes of undocking, floating, positioning, and sinking with water proceed. The sealing test of the steel caisson serves the following purposes: ensuring that the steel shell does not leak during floating, thus guaranteeing the safety of the floating process; and ensuring that the walls and compartments of the caisson do not leak, facilitating adjustments to the caisson's attitude during sinking with water and ensuring the accuracy of the descent.

[0003] Currently, the main methods for inspecting the sealing performance of steel caissons are: weld appearance inspection, ultrasonic non-destructive testing, and kerosene penetration testing. These methods still have the following technical problems: (1) The steel shell of the caisson is manufactured in sections and then assembled as a whole, resulting in a large number of welds. The above methods are prone to missing inspections. (2) The steel shell structure of the caisson is complex, with many components in the well wall and compartments, making it difficult for personnel to enter for inspection. (3) The interior of the caisson is dark, and the accuracy of visual inspection of cracks is low. (4) The above methods cannot accurately simulate the sealing performance of the steel shell of the caisson under actual water pressure. (5) The buoyancy plate at the bottom of the caisson is connected to the steel shell of the caisson by bolts, and a rubber strip is sealed between them for water stoppage. The above methods are not suitable for the sealing performance inspection of this type of structure. (6) The above methods require a lot of manpower and time, and ultrasonic non-destructive testing and kerosene penetration testing are costly. (7) In particular, the residue needs to be cleaned after the kerosene penetration test is completed, which is a complicated process. Summary of the Invention

[0004] The main technical problem to be solved by the present invention is to provide a method for testing the sealing performance of steel caisson structures, so as to achieve efficient, convenient, comprehensive, accurate, safe and reliable testing results.

[0005] To address the aforementioned technical problems, this invention provides a method for inspecting the sealing performance of a steel caisson structure. Structurally, the main body of the steel caisson is a steel shell; the steel shell is constructed from several compartments; the steel caisson also includes a buoyancy aid plate sealed and connected to the bottom of the steel shell.

[0006] The method includes the following steps:

[0007] Step 1: Divide the compartment into several symmetrically distributed zones; keep any two adjacent zones sealed, while the compartments within the same zone are connected to each other at the bottom;

[0008] For any given zone, at least one compartment is designed to be a water-filled compartment, while the remaining compartments are equipped with sealing plates.

[0009] Furthermore, the zone is divided into several batches according to the water injection sequence;

[0010] Step 2: Install water injection and drainage systems and water level monitoring systems;

[0011] The water injection and drainage system includes at least two water injection pumps and a drainage pump; the water injection pumps are located outside the steel caisson and inject water into the partition through an external water pipe; the drainage pumps are located at the bottom of the water injection compartments in each partition.

[0012] The water level monitoring system includes several water level gauges and a monitoring host; the water level gauges are installed at the bottom of the partition and feed back the water level monitoring data to the monitoring host;

[0013] Step 3: Fill the dock with water to the buoyancy level and check the sealing of the buoyancy aid plate; the buoyancy level shall not be lower than the installation height of the buoyancy aid plate;

[0014] Step 4: Use the water injection pump to inject water into the water injection compartment of the first batch of zones; when the water level in the water injection compartment stabilizes at the first height, observe whether there is water overflowing from each sealing plate in the first batch of zones; the first height is higher than the setting height of the sealing plate;

[0015] Step 5: Continue to inject water into the first batch of zones to the second height to check the structural airtightness of this batch of zones; the second height is the maximum water injection height that will not damage the safety of the steel caisson structure;

[0016] The inspection of the sealing performance of the above-mentioned partition structure includes: visually inspecting whether the walls and compartments of the steel caisson are leaking water outwards, and then continuously monitoring the water level changes within the partition using the water level monitoring system; if the water level monitoring data is abnormal, the leak point needs to be manually investigated.

[0017] Step 6: Referring to Steps 4 and 5, perform water injection and sealing tests on the remaining batches of partitions;

[0018] Step 7: After the inspection is completed, use the drainage pump to drain the water from all zones to provide a dry working environment for the repair work.

[0019] In a preferred embodiment, step 3 further includes:

[0020] When the water level in the dock reaches the third height, the cavity that may exist at the bottom of the buoyancy plate is drained through the water injection valve installed on the top of the buoyancy plate.

[0021] The third height is not lower than the height of the bottom cutting edge of the steel caisson, and is lower than the buoyancy-aiding height.

[0022] In a preferred embodiment, the partitions of the same batch are symmetrical about the center point of the steel caisson.

[0023] In a preferred embodiment, the water injection method in step 5 is to inject water into each compartment in the first batch of partitions.

[0024] In a preferred embodiment, the water injection method in step 5 is as follows: a connecting hole is pre-set on the wall of the water injection compartment; the position of the connecting hole is higher than the sealing plate; water is continued to be injected into the water injection compartment to submerge the connecting hole, which can also achieve water injection into the compartments of the same area.

[0025] In a preferred embodiment, in step 3, the value of the buoyancy assist height is not greater than the draft of the steel caisson in the sealed state, and the difference between the two is within 1.0 meter.

[0026] In a preferred embodiment, in step 2, one water level gauge is installed in each of the compartments.

[0027] In a preferred embodiment, in step 2, the external water pipe is a steel pipe;

[0028] The outer wall of the steel caisson is provided with several temporary fixing frames at intervals along the height direction to provide segmented support for the external water pipe.

[0029] In a preferred embodiment, the partition includes three or four of the compartments.

[0030] In a preferred embodiment, the water injection pump is a permanent magnet pump, and the drainage pump is a high-lift water pump.

[0031] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0032] (1) The method creatively adopts a batch water injection approach to inspect the sealing performance of steel caissons. This not only enables batch inspection of large-scale weld quality and effectively solves the problem of missed inspections in existing technologies, but also demonstrates comprehensiveness. Furthermore, this method allows weld defects to be visualized, making it easier for inspectors to discover and identify them, thus making the inspection work more convenient and efficient.

[0033] (2) The method injects high-level water into the steel shell of the dock and caisson, accurately simulating the water pressure experienced by the steel caisson during operation. Therefore, the method can scientifically and objectively evaluate the strength of the weld under pressure and the structural stability of the steel caisson during floating and sinking, and has high scientific validity and reliability.

[0034] (3) The method employs the water level monitoring system to monitor the water level changes in each compartment in real time. This method replaces the traditional manual measurement method, which not only simplifies the testing process but also ensures the accuracy of the test data. Therefore, the water level monitoring system not only improves work efficiency but also reduces human error, making the test results more accurate.

[0035] (4) Most existing inspection methods only inspect the welds of steel structures. However, the method provided by this invention can not only inspect the weld quality of the caisson steel shell itself, but also the sealing performance of the watertight structure between the caisson steel shell and the buoyancy aid plate. Therefore, the inspection items of the method are more complete and comprehensive, and it has higher applicability and can be used for the inspection of various watertight structures.

[0036] (5) Existing testing methods typically rely on sophisticated testing instruments. These instruments are not only expensive but also require highly skilled personnel. The method provided by this invention, however, does not require sophisticated instruments; personnel only need to operate a water pump switch to easily complete the testing. Therefore, this method is convenient, efficient, and requires less skilled personnel, making it more suitable for widespread application.

[0037] (6) After the inspection is completed, the method only needs to drain the water in the steel caisson through the high-lift water pump, without cleaning the inspection residue, which is convenient and environmentally friendly. Attached Figure Description

[0038] Figure 1 This is a top view of the steel shell of the caisson described in an embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram of the compartments described in the embodiments of the present invention (the colors in the diagram are only for the convenience of understanding the range and boundaries of each compartment and do not represent the actual color characteristics of each compartment).

[0040] Figure 3 This is a schematic diagram of the plan layout of the water injection and drainage system described in the embodiment of the present invention (the colors in the figure are only for the convenience of understanding the range and boundaries of each zone, and do not represent the actual color characteristics of each zone).

[0041] Figure 4 This is a schematic diagram of the elevation layout of the water injection and drainage system described in an embodiment of the present invention;

[0042] Figure 5 This is a schematic diagram of the plan layout of the water level monitoring system described in the embodiment of the present invention (the colors in the figure are only for the convenience of understanding the range and boundaries of each zone, and do not represent the actual color characteristics of each zone).

[0043] Figure 6 This is a schematic diagram of the elevation layout of the water level monitoring system described in this embodiment of the invention;

[0044] Figure 7 This is a flowchart of the water injection inspection stage of the method described in this embodiment of the invention;

[0045] Figure 8 This is a schematic diagram of the bottom cavity of the buoyancy plate described in an embodiment of the present invention.

[0046] The markings in the diagram are as follows: 1-caisson steel shell, 11-compartment, 111-sealing plate, 12-well wall, 13-well hole, 14-cutting foot, 15-cutting foot concrete, 2-buoyancy aid plate, 21-water injection valve, 22-cavity, 3-water injection and drainage system, 31-permanent magnet pump, 311-external water pipe, 312-temporary fixing frame, 32-high lift water pump, 33-operation cabinet, 4-water level monitoring system, 41-water level gauge, 42-monitoring host, 43-monitoring cabling, 5-construction platform. Detailed Implementation

[0047] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0048] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0049] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed", "equipped", "sleeved / connected", "connected", etc., should be interpreted broadly. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0050] like Figures 1 to 8As shown, this embodiment of the invention provides a method for inspecting the sealing performance of a steel caisson structure. To facilitate the explanation of the implementation steps of the method, the structural design and construction zoning of the steel caisson are first described.

[0051] like Figure 1 As shown, the steel caisson is generally square, measuring 66 meters long and 48 meters wide horizontally, with a total height of 31.6 meters including the supporting cofferdam. The main body of the steel caisson is a porous steel shell, hereinafter referred to as caisson steel shell 1. On the horizontal plane, the caisson steel shell 1 is divided into 35 independent compartments 11. Three or four adjacent compartments 11 form a section, dividing the caisson steel shell 1 into nine symmetrically distributed sections. The specific numbering of the compartments and sections is as follows... Figure 2 As shown. Any two adjacent sections remain sealed, while the compartments within each section are interconnected. To avoid confusion, the compartments mentioned below will be accompanied by specific designations.

[0052] For each zone, one compartment is selected as the water injection compartment, such as compartment 6 in zone 1, compartment 3 in zone 2, compartment 16 in zone 4, compartment 18 in zone 5, etc. Except for zone 5, the water injection compartments should be selected close to the outer perimeter of the steel caisson to facilitate subsequent water injection and drainage. Within the same zone, the water injection compartments are installed at full height without sealing plates, while the adjacent compartments are equipped with sealing plates 111 at a position slightly below 10.0 meters (see...). Figure 4 or Figure 6 The function of the sealing plate 111 is to control the speed of the steel caisson's sinking during water injection in the sea, ensuring the stability of the caisson's sinking posture and preventing it from capsizing. As this is a common technique in the field, it will not be elaborated upon here. The compartments within the same zone are connected to each other near the bottom. Therefore, subsequent water injection into the water-filled compartments will raise the water level of all compartments within the same zone to the height of the sealing plate 111.

[0053] Depend on Figures 1-6 It is known that the 35 compartments construct 24 well holes 13 within the internal space of the steel caisson. The steel caisson also includes 24 buoyancy aids 2. The buoyancy aids 2 are sealed to the bottom of the well holes 13, providing buoyancy for the steel caisson during undocking and floating. In this embodiment, the total drainage area of ​​the steel caisson after sealing is approximately 3155 square meters. Based on the self-weight of the steel caisson model, its draft in buoyancy mode can be estimated to be approximately 5 meters. The buoyancy aids 2 are detachable. During the positioning and sinking of the steel caisson, the draft of the steel caisson can be controlled by gradually and symmetrically removing some of the buoyancy aids 2. Additionally, a cutting edge 14 is provided along the circumference at the bottom of the steel caisson to cut through the soil during the sinking process, thereby reducing sinking resistance.

[0054] like Figure 7 As shown, the present invention mainly tests the structural sealing of the steel caisson through the following aspects: (1) injecting water into the dock and observing whether the water enters the interior of the steel caisson through the edge of the buoyancy plate 2 to check the connection sealing of the buoyancy plate 2; (2) injecting water into each of the partitions one by one to check: ① the sealing of the sealing plate 111; ② whether the well wall 12 and the compartment of the steel caisson leak water to the outside; ③ whether there is mutual leakage between any adjacent partitions. It can be understood that the above points ② and ③ are the "checking the sealing of the caisson" as shown in the figure. It should be noted that the well wall 12 refers to the outermost ring structure of the steel shell 1 of the caisson, which is an important barrier and the main load-bearing body of the steel caisson. Figure 1 It can be seen that the well wall 12 is composed of the outermost ring of compartments.

[0055] The following text combines Figures 1 to 8 The implementation steps of the method are described in detail.

[0056] Step 1: Divide the steel caisson into compartments. The specific division is as described above and will not be repeated here.

[0057] Step 2: Install water injection and drainage systems and water level monitoring systems.

[0058] like Figures 3-4 As shown, a construction platform 5 is erected on top of the steel caisson, and the water injection and drainage system 3 is laid out using the construction platform 5. In this embodiment, two permanent magnet pumps 31 are used for water injection. The two permanent magnet pumps 31 are symmetrically installed on the outside of the steel caisson, close to the outer side of the caisson wall 12, to facilitate symmetrical water injection into the above-mentioned nine zones. The model of the permanent magnet pump 31 needs to be selected according to the maximum water injection volume per cycle. For this embodiment, it is recommended to control the water injection time to within 2 hours to reduce waiting time.

[0059] The permanent magnet pump 31 injects water from the dock into the compartment via an external water pipe 311. The selection of the external water pipe 311 must meet two requirements: first, its diameter must be large enough to transport the water flow rate when the permanent magnet pump 31 operates at maximum power; second, a steel pipe must be used, as it can withstand higher working water pressure and is easier to fix than a flexible hose. Because the external water pipe 311 is relatively long, several temporary fixing brackets 312 need to be installed at intervals along the height of the well wall 12 to provide segmented support for the external water pipe 311. The elbows and straight sections of the external water pipe 311 are connected by flanges for easy installation and removal. To facilitate quick adjustment of the outlet position for water injection into designated areas, the external water pipe 311 is extended to the construction platform 5 at the top of the steel caisson and then extended using a flexible hose. The flexible hose is connected to the external water pipe 311 using a fixing clamp.

[0060] In this embodiment, the drainage pump is a high-lift water pump 32, and one high-lift water pump 32 is installed in each section. As shown in the figure, and as can be seen from the above, the high-lift water pump 32 is located at the bottom of the water injection compartment in each section. To allow for timely operation of the electromagnetic pump and the high-lift water pump 32 according to the actual site conditions, the control cabinets 33 of all pumps are installed on the construction platform 5 at the top of the steel caisson, and several operators are assigned to operate them in the vicinity of the construction platform 5. The plan layout of the water injection and drainage system 3 is shown in the figure.

[0061] like Figures 5-6 As shown, the water level monitoring system 4 includes several water level gauges 41 and a monitoring host 42. One water level gauge 41 is installed in each compartment. The water level gauge 41 is installed on the top surface of the cutting edge concrete 15 and is used to monitor changes in water level within the compartment. The monitoring data from each water level gauge 41 is collected and aggregated into the monitoring host 42 via a monitoring cable 43, and is monitored by designated personnel to promptly relay water level information to the pump operators.

[0062] Step 3: Fill the dock with water and check the sealing of the buoyancy plate 2.

[0063] Water is pumped into the dock using its own pump. When the water level reaches 1.0 meter, the water surface covers the cutting edge 14. In this embodiment, the 1.0 meter is the third height described in the claims. Figure 8 As shown, at this time, some air remains below the buoyancy plate 2, forming a sealed cavity 22. This cavity 22 hinders the water level from rising to the bottom of the buoyancy plate 2, affecting subsequent inspection work. Therefore, the water injection valve 21, pre-installed on the top of the buoyancy plate 2, needs to be opened to expel the air from the steel caisson within the cavity 22. After the air is expelled, the water injection valve 21 is closed. Then, water is continuously injected into the dock to a level of 4.5 meters. The system is visually inspected for water seepage into the steel caisson from the edge of the buoyancy plate 2, and any leaks are marked and documented. It is understood that in this embodiment, the buoyancy height is 4.5 meters. The reason for setting the observation water level at 4.5 meters is that if the water injection height is too high, the steel caisson will float, which may cause uncontrolled swaying, posing a safety risk to the operators; if the water injection height is too low, the actual working water pressure of the buoyancy plate 2 cannot be accurately simulated.

[0064] Step 4: Fill the first batch of zones with water to a height of 10.0 meters and check the sealing performance of the sealing plate 111.

[0065] Continue filling the dock with water to submerge the permanent magnet pump 31. Then, activate the permanent magnet pump 31 to inject water into the sections of the steel caisson. To ensure uniform stress distribution throughout the steel caisson, water must be injected symmetrically into each section. In this embodiment, the specific water injection sequence is as follows: First batch: simultaneous injection of water into sections two and eight; Second batch: simultaneous injection of water into sections one and nine; Third batch: simultaneous injection of water into sections three and seven; Fourth batch: simultaneous injection of water into sections four and six; Fifth batch: injection of water into section five.

[0066] The following steps will be explained using the first batch of water-filled zones—zones two and eight—as examples. As mentioned above, simply injecting water into water-filled compartments 3 and 33 will raise the water level in all compartments within zones two and eight, respectively. For zones two and eight, when the water level in the water-filled compartments rises and stabilizes at 10.0 meters, it indicates that the water level in all compartments within that zone has reached the height of the sealing plate 111. Therefore, at this point, the sealing performance can be checked by visually observing whether water is seeping upwards from each sealing plate 111. If leakage is found, the leakage points should be marked and video evidence recorded. It should be understood that in this embodiment, the first height in the claims is 10.0 meters.

[0067] Step 5: Continue filling the first batch of sections with water to a height of 19.5 meters to check the structural sealing of this batch of sections.

[0068] For partition two or partition eight, after checking the sealing performance of the sealing plate 111, water can be injected synchronously to a height of 19.5 meters. Since sealing plates 111 are installed in the other compartments besides the water injection compartment, the water level cannot continue to rise. Therefore, there are two ways to inject water in this step: (1) inject water into each compartment to a height of 19.5 meters; (2) set a connecting hole in advance on the wall of the water injection compartment at a position higher than the sealing plate 111, and then continue to inject water into the water injection compartment, which can also make the water level in the compartment of the same partition rise. When the water level of all compartments in partition two and partition eight reaches 19.5 meters, visually observe whether the well wall 12 and compartments of the above partitions are leaking water. Then, use the water level monitoring system 4 to continuously monitor the water level changes of each compartment in the above partitions. If the water level recorded in the water level monitoring system 4 drops, manual investigation is required, and the leak point is marked and image data is retained. It should be understood that, in this embodiment, the second height in the claims is 19.5 meters.

[0069] The reason for setting the observation water level at 19.5 meters in this step is that: if the water injection height is too high, the water level difference between the inside and outside of the compartment will be too large, causing the compartment wall to be damaged due to excessive water pressure, which will seriously affect the structural strength of the steel caisson. If the water injection height is too low, the working area for this inspection will be too small. Therefore, after performing stress analysis and verification on the steel caisson in this embodiment, the water injection height in this step is set at 19.5 meters to ensure that the structural strength of the steel caisson itself is within a safe range. Therefore, in this embodiment, the so-called 19.5 meters can be understood as the maximum water injection height to ensure that the steel caisson does not suffer structural damage. For steel caissons of different shapes and sizes, the second height corresponds to different values, which need to be analyzed on a case-by-case basis.

[0070] Step 6: Refer to Steps 3 and 4 to inspect the remaining batches of each zone.

[0071] like Figure 2 As shown, specifically, water was simultaneously injected into the second batch of analyses—sections one and nine. When the water level reached 10.0 meters, the sealing plates 111 in both sections were inspected, and when the water level reached 19.5 meters, the overall structural sealing of the two sections was inspected. Then, following the above water injection sequence, the third, fourth, and fifth batches of sections were inspected respectively.

[0072] Step 7: After all zones have been inspected, drain the water from each zone.

[0073] After confirming that all zones have been inspected and leak points recorded, the high-lift water pump 32 is turned on to simultaneously pump out water from each zone, providing a dry working environment for subsequent repair work. This completes the structural sealing inspection of the steel caisson.

[0074] The following section analyzes the technical advantages of the method provided in this embodiment, based on the steps described above.

[0075] (1) The method creatively adopts a batch water injection approach to inspect the sealing performance of steel caissons. This not only enables batch inspection of large-scale weld quality and effectively solves the problem of missed inspections in existing technologies, but also demonstrates comprehensiveness. Furthermore, this method allows weld defects to be visualized, making it easier for inspectors to discover and identify them, thus making the inspection work more convenient and efficient.

[0076] (2) The method injects high-level water into the steel shell 1 of the dock and caisson, accurately simulating the water pressure experienced by the steel caisson during operation. Therefore, the method can scientifically and objectively evaluate the strength of the weld under pressure and the structural stability of the steel caisson during floating and sinking, and has high scientific validity and reliability.

[0077] (3) The method employs the water level monitoring system to monitor the water level changes in each compartment in real time. This method replaces the traditional manual measurement method, which not only simplifies the testing process but also ensures the accuracy of the test data. Therefore, the water level monitoring system not only improves work efficiency but also reduces human error, making the test results more accurate.

[0078] (4) Most existing inspection methods inspect the welds of steel structures. However, the method provided in this embodiment can not only inspect the weld quality of the caisson steel shell 1 itself, but also inspect the sealing performance of the water-stop structure between the caisson steel shell 1 and the buoyancy plate 2. Therefore, the inspection items of the method are more complete and comprehensive, and it has higher applicability and can be used for the inspection of various watertight structures.

[0079] (5) Existing testing methods typically rely on sophisticated testing instruments. These instruments are not only expensive but also require highly skilled personnel. The method described in this embodiment, however, does not require sophisticated instruments; personnel only need to operate a water pump switch to easily complete the testing. Therefore, this method is convenient, efficient, and requires less skilled personnel, making it more suitable for widespread application.

[0080] (6) After the inspection is completed, the water in the steel caisson only needs to be drained by the high-lift water pump 32, without cleaning the inspection residue, which is convenient and environmentally friendly.

[0081] The above description is merely a preferred embodiment of the present invention and is not intended to limit the patent scope of the present invention. Any technically equivalent modifications made based on the content of this specification shall fall within the protection scope of the present invention.

Claims

1. A method for inspecting the sealing performance of a steel caisson structure, characterized in that: Structurally, the main body of the steel caisson is a steel shell; the steel shell is composed of several compartments; the steel caisson also includes a buoyancy aid plate sealed and connected to the bottom of the steel shell. The method includes the following steps: Step 1: Divide the compartment into several symmetrically distributed zones; keep any two adjacent zones sealed, while the compartments within the same zone are connected to each other at the bottom; For any given zone, at least one compartment is designed to be a water-filled compartment, while the remaining compartments are equipped with sealing plates. The zone is divided into several batches according to the water injection sequence; Step 2: Install water injection and drainage systems and water level monitoring systems; The water injection and drainage system includes at least two water injection pumps and a drainage pump; the water injection pumps are located outside the steel caisson and inject water into the partition through an external water pipe; the drainage pumps are located at the bottom of the water injection compartments in each partition. The water level monitoring system includes several water level gauges and a monitoring host; the water level gauges are installed at the bottom of the partition and feed back the water level monitoring data to the monitoring host; Step 3: Fill the dock with water to the buoyancy level and check the sealing of the buoyancy aid plate; the buoyancy level shall not be lower than the installation height of the buoyancy aid plate; Step 4: Use the water injection pump to inject water into the water injection compartment of the first batch of zones; when the water level in the water injection compartment stabilizes at the first height, observe whether there is water overflowing from each sealing plate in the first batch of zones; the first height is higher than the setting height of the sealing plate; Step 5: Continue to inject water into the first batch of zones to the second height to check the structural airtightness of this batch of zones; the second height is the maximum water injection height that will not damage the safety of the steel caisson structure; The inspection of the sealing performance of the above-mentioned partition structure includes: visually inspecting whether the walls and compartments of the steel caisson are leaking water outwards, and then continuously monitoring the water level changes within the partition using the water level monitoring system; if the water level monitoring data is abnormal, the leak point needs to be manually investigated. Step 6: Referring to Steps 4 and 5, perform water injection and sealing tests on the remaining batches of partitions; Step 7: After the inspection is completed, use the drainage pump to drain the water from all zones to provide a dry working environment for the repair work.

2. The method for testing the sealing performance of a steel caisson structure according to claim 1, characterized in that: Step 3 also includes: When the water level in the dock reaches the third height, the cavity that may exist at the bottom of the buoyancy plate is drained through the water injection valve installed on the top of the buoyancy plate. The third height is not lower than the height of the bottom cutting edge of the steel caisson, and is lower than the buoyancy-aiding height.

3. The method for testing the sealing performance of a steel caisson structure according to claim 1, characterized in that: The partitions of the same batch are symmetrical about the center point of the steel caisson.

4. The method for testing the sealing performance of a steel caisson structure according to claim 1, characterized in that: The water injection method in step 5 is to inject water into each compartment in the first batch of zones.

5. The method for testing the sealing performance of a steel caisson structure according to claim 1, characterized in that: The water injection method in step 5 is as follows: a connecting hole is pre-set on the wall of the water injection compartment; the position of the connecting hole is higher than the sealing plate; water is continued to be injected into the water injection compartment until it is submerged in the connecting hole, which can also achieve water injection into the compartments of the same area.

6. The method for testing the sealing performance of a steel caisson structure according to claim 1, characterized in that: In step 3, the buoyancy height is not greater than the draft of the steel caisson in the sealed state, and the difference between the two is within 1.0 meter.

7. The method for testing the sealing performance of a steel caisson structure according to claim 1, characterized in that: In step 2, a water level gauge is installed in each of the compartments.

8. The method for testing the sealing performance of a steel caisson structure according to claim 1, characterized in that: In step 2, the external water pipe is made of steel. The outer wall of the steel caisson is provided with several temporary fixing frames at intervals along the height direction to provide segmented support for the external water pipe.

9. The method for testing the sealing performance of a steel caisson structure according to claim 1, characterized in that: The partition includes three or four of the compartments.

10. The method for testing the sealing performance of a steel caisson structure according to claim 1, characterized in that: The water injection pump is a permanent magnet pump, and the drainage pump is a high-lift water pump.

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