Pre-paving immersed tube tunnel foundation trench back silting detection method and sampler

Abstract

The invention relates to a pre-paving immersed tube tunnel foundation trench back-silting detection method and a sampler, and belongs to the technical field of immersed tube tunnel foundation trench back-silting detection.The detection method comprises the following steps that S1, when detection is needed, an RTK receiver is installed on a detection platform, and the detection platform is moved to a detection point through GPS positioning; s2, putting down the sampler for sampling, lifting up a sealing lifting lead of the sampler after sampling is completed, and pulling a sealing diaphragm to block an opening in the bottom of the sampler; s3, upwards extracting the sampler until the sampler leaves the water surface, keeping the sampler in an upright state, and measuring the thickness of each layer of back silt in the sampler; s4, extracting each layer of back-silting sample in the sampler, and carrying out a specific gravity test to obtain the density of a back-silting object; and S5, according to the thickness and density of the back silting object, whether desilting needs to be conducted or not is judged. According to the detection method, opening and closing of the sealing diaphragm are controlled through the sealing lifting lead, diving operation is not needed, and manpower and equipment cost is reduced; and the thickness and the density of the back-silting sample can be accurately obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of siltation detection for a foundation trench of an immersed tube tunnel, and in particular relates to a siltation detection method for a foundation trench of an immersed tube tunnel using a pre-laying method and a sampler. Background Art

[0002] At present, my country has successfully built and completed several immersed tube tunnel projects and has accumulated rich experience and advanced technology in the field of first-laid immersed tube tunnels. With its many advantages, immersed tube tunnels are gradually becoming the first choice of tunnel structure form in new projects.

[0003] During the processes of foundation trench excavation, block vibration and crushed stone leveling, and immersed tube tunnel installation, it is necessary to pay attention to the siltation situation at all times. The premise for setting up siltation prevention and dredging measures is to accurately grasp the amount of siltation. Siltation comes from two aspects: one is the flow of water, which carries sediment and is called scouring and silting; the other is that due to the excavation of the immersed tube foundation trench, the cross-sectional area of ​​the water body is increased, the water flow rate is reduced, and the sedimentation is aggravated, which is called falling siltation. The amount of siltation is a key parameter for the quality control of the immersed tube tunnel construction by the first laying method. Generally, the thickness and density of the siltation need to be tested.

[0004] In the prior art, siltation monitoring often uses the siltation box method and the multi-beam measurement method. The siltation box method is to place a siltation box in the foundation trench and extract the siltation amount at intervals. The siltation box method requires diving to place the box and to close the siltation box cover underwater when lifting it, which is very costly. In addition, the siltation box can only observe siltation and generates eddy currents on the top of the box, which aggravates the local siltation in the siltation box. The data cannot truly reflect the siltation situation. The multi-beam measurement method is an indirect measurement method, and when the water is turbid or the interface characteristics are not obvious, the error is often large.

[0005] Therefore, how to solve the current detection problem of immersed tube tunnel foundation trench siltation is a technical problem that urgently needs to be solved. Summary of the invention

[0006] In view of the shortcomings in the prior art, the present invention provides a method and sampler for detecting siltation in a foundation trench of an immersed tube tunnel using a pre-laying method. The opening and closing of a sealing membrane is controlled by a sealing lifting wire, and no diving operation is required, thereby simplifying the operation process and reducing manpower and equipment costs. The method also ensures that the thickness and density of the siltation sample can be accurately obtained, thereby avoiding data distortion caused by eddy currents in the existing siltation box method. Compared with the multi-beam measurement method, the method is not affected by water turbidity and provides more reliable detection data.

[0007] The present invention provides a method for detecting siltation in a foundation trench of a pre-laid immersed tube tunnel, comprising the following steps:

[0008] S1, when testing is needed, install an RTK receiver on the testing platform, use GPS positioning to move the testing platform to the testing point;

[0009] S2, lower the sampler to take samples, and after the sampling is completed, pull up the sealing lead of the sampler to pull the sealing film to seal the bottom opening of the sampler;

[0010] S3, lift the sampler up to the water surface, keep the sampler upright, and measure the thickness of each layer of silt in the sampler;

[0011] S4, extracting silt samples from each layer in the sampler to perform a specific gravity test to obtain the density of the silt;

[0012] S5, judging whether dredging is required according to the thickness and density of the silt.

[0013] This technical solution controls the opening and closing of the sealing membrane through the sealing lifting wire, without the need for diving operations, thus simplifying the operating process and reducing manpower and equipment costs; and ensures that the thickness and density of the siltation sample can be accurately obtained, avoiding data distortion caused by eddy current phenomena in the existing siltation box method; compared with the multi-beam measurement method, it is not affected by water turbidity and provides more reliable detection data.

[0014] In some embodiments, in step S1, the time and detection point to be detected include:

[0015] The immersed tube segment foundation trench shall be inspected once on the 7th day after fine excavation and before rock dumping. Each segment shall be inspected at selected inspection points.

[0016] The test is conducted once on the 15th day and the 7th day after the block is vibrated and compacted and before the crushed stone is leveled. The test points are selected for each pipe section.

[0017] After the gravel is leveled and before the pipe section is placed, the test is conducted once on the 7th day, 5th day, 3rd day and 1st day respectively. Each pipe section is tested at a selected testing point.

[0018] The slope of the foundation pit shall be inspected once on the 15th day before gravel leveling, on the 7th day before pipe section sinking, and after extreme weather.

[0019] Through the specific arrangement of detection time and selection of detection points, this technical solution enables the dynamics of foundation trench siltation to be monitored in real time during the construction process, and silt removal measures to be taken in a timely manner to ensure construction quality and safety.

[0020] In some embodiments, in step S5, the density is greater than 1.26 g / cm 3 The thickness of the siltation is h1, and the density is more than 1.15g / cm 3 The siltation thickness is h2, and silt removal is carried out when any of the following conditions are met:

[0021] When the silt thickness h1 obtained in any test after the fine excavation of the immersed tube segment foundation trench and before the block filling is greater than 20cm, silt removal shall be carried out;

[0022] When the thickness of siltation h1>10cm or h2>30cm is obtained in any test after the block is vibrated and before the crushed stone is leveled, silt removal shall be carried out;

[0023] When the thickness of siltation h1>4cm or h2>10cm is obtained in any test after the gravel is leveled and before the pipe section is laid, silt removal shall be carried out;

[0024] When the silt thickness h1 obtained from any monitoring of the slope surface of the foundation trench is greater than 40 cm, silt removal is carried out.

[0025] This technical solution decides whether to carry out dredging operations according to different construction stages and the conditions for detecting siltation density and thickness. It can not only improve the accuracy and efficiency of siltation detection, but also ensure that dredging measures are taken in a timely manner at each key node of the construction.

[0026] In some of the embodiments, in step S3, when measuring the thickness of each layer of silt in the sampler, when there is an interface between the layers of silt, the thickness of each layer of silt is directly measured; when the layers of silt are turbid and there is no interface, the layer of silt is left to stand until an interface appears and then the thickness of each layer of silt is measured.

[0027] The technical solution adopts a static method to make the turbid silt produce an interface, and then performs thickness measurement, thereby improving the accuracy and reliability of the measurement, especially in the case of high turbidity.

[0028] In some of the embodiments, in step S1, a traction rope is used to fix the top of the sampler to lower the sampler, and when the sampler is lowered, the sealing membrane is fixed in position by using the hook of the connecting piece and the membrane fixing piece; in step S2, after the sampler penetrates the silt and touches the bottom to complete the sampling, the traction rope is relaxed, the hook is separated from the membrane fixing piece, and the positioning of the sealing membrane is released. At this time, the sealing lifting lead is lifted to pull the sealing membrane to move the sealing membrane to the bottom opening of the sampler; in step S3, the traction rope is lifted to pull the sampler upward.

[0029] In some of the embodiments, the sealing lifting lead is passed through a lifting lead sleeve, and a detachable fixing block is installed at the top opening of the lifting lead sleeve. In step S2, after the sealing lifting lead is lifted, the opening at the top of the lifting lead sleeve is blocked by the fixing block, and the sealing lifting lead is fixed at the same time.

[0030] In addition, the present invention also provides a siltation sampling device for a foundation trench of a pre-laid immersed tube tunnel, which adopts the siltation detection method for a foundation trench of a pre-laid immersed tube tunnel as described above, comprising:

[0031] The sampling tube is used to hold the siltation sample of the foundation trench, and the bottom of the sampling tube is provided with an opening and the top is fixed with a bracket;

[0032] A sealing film is provided at the bottom of the sampling tube and is used to seal the opening after sampling;

[0033] One end of the sealing lead wire is connected to the sealing film through the bottom of the sampling tube, and the other end is controlled by the staff. When the sealing lead wire is pulled up, the sealing lead wire pulls the sealing film to move and seal the opening.

[0034] This technical solution ensures the accurate acquisition of the siltation sample by setting an opening at the bottom of the sampling tube and sealing it with a sealing membrane, avoiding data distortion caused by eddy current phenomenon in the traditional siltation box method; through the setting of the sealing lifting wire, the operator can easily control the opening and closing of the sealing membrane without diving operation, reducing the difficulty and cost of operation.

[0035] In some embodiments, the siltation sampling device for the tunnel foundation trench of the first-laid immersed tube method further includes a traction rope, one end of which is connected to the top bracket of the sampling tube, and the other end of which is controlled by the staff to be retracted and released, and is used to lift or lower the sampling tube. The technical solution facilitates the staff to lift or lower the sampling tube by controlling the traction rope through the provision of the traction rope, thereby improving the flexibility and safety of the sampling process.

[0036] In some of the embodiments, the submerged tube tunnel foundation trench backsilt sampler of the pre-laying method also includes a connecting piece and a diaphragm fixing piece, one end of the connecting piece is connected to a traction rope, and the other end is provided with a hook, the hook is connected to the diaphragm fixing piece, and the end of the diaphragm fixing piece away from the hook is connected to the sealing diaphragm; during the lowering process of the sampler, the hook is connected to the diaphragm fixing piece to fix the position of the sealing diaphragm, and when the bottom of the sampler touches the bottom, the traction rope is loosened, the hook and the diaphragm fixing piece are automatically separated, and the sealing diaphragm is released.

[0037] In some of the embodiments, the siltation sampler for the immersed tube tunnel foundation trench using the paving-first method also includes a lifting wire sleeve and a fixing block which are sleeved on the outer periphery of the sealing lifting wire. The fixing block is arranged at the end of the lifting wire sleeve away from the sealing membrane, and is used to clamp the lifting wire sleeve to fix the height of the lifting wire.

[0038] Based on the above scheme, the method and sampler for detecting siltation in the foundation trench of an immersed tube tunnel by the paving-first method in the embodiment of the present invention control the opening and closing of the sealing membrane by a sealing lifting wire, and do not require diving operations, thereby simplifying the operating process and reducing manpower and equipment costs; and ensuring that the thickness and density of the siltation samples can be accurately obtained, thereby avoiding data distortion caused by eddy current phenomena in the existing siltation box method; compared with the multi-beam measurement method, it is not affected by water turbidity and provides more reliable detection data; in summary, the method for detecting siltation in the foundation trench of an immersed tube tunnel by the paving-first method in the embodiment of the present invention can simultaneously detect the siltation caused by scouring and falling siltation, and can improve the efficiency and data accuracy of siltation detection in the foundation trench of an immersed tube tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0040] Figure 1 Flow chart of a method for detecting siltation in a foundation trench of an immersed tube tunnel using a pre-laying method according to an embodiment of the present invention;

[0041] Figure 2 It is a schematic diagram of the structure of a siltation sampler for a foundation trench of a submerged tube tunnel using a pre-laying method according to an embodiment of the present invention;

[0042] Figure 3 It is a bottom view of the siltation sampler for the foundation trench of a submerged tube tunnel using the pre-laying method according to an embodiment of the present invention;

[0043] Figure 4 for Figure 2 A magnified schematic diagram of part A;

[0044] Figure 5 for Figure 2 A magnified schematic diagram of part B;

[0045] Figure 6 It is a schematic diagram of the structure of the lifting wire fixing device of the foundation trench siltation sampler of the immersed tube tunnel by the pre-laying method in an embodiment of the present invention.

[0046] In the figure:

[0047] 1. Sampling tube; 2. Sealing membrane; 3. Sealing lead wire; 4. Traction rope; 5. Diaphragm fixing part; 6. Connecting part; 7. Diaphragm pull lead wire;

[0048] 101, diaphragm fixing point; 102, counterweight block; 103, bracket;

[0049] 201, first lifting point; 202, second lifting point;

[0050] 301, lifting lead jacket; 302, fixing block;

[0051] 601. Hook. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0053] In the description of the present invention, it is necessary to understand that the terms "center", "lateral", "longitudinal", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0054] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0055] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] like Figure 1 As shown, in one embodiment of the method for detecting siltation in a foundation trench of a submerged tube tunnel using a paving-first method and a sampler of the present invention, the method for detecting siltation in a foundation trench of a submerged tube tunnel using a paving-first method comprises the following steps:

[0057] S1, when testing is needed, install an RTK receiver on the testing platform, use GPS positioning to move the testing platform to the testing point;

[0058] S2, lower the sampler to take samples, and after the sampling is completed, pull up the sealing lead wire 3 of the sampler to pull the sealing film 2 to seal the bottom opening of the sampler;

[0059] S3, lift the sampler up to the water surface, keep the sampler upright, and measure the thickness of each layer of silt in the sampler;

[0060] S4, extracting silt samples from each layer in the sampler to perform a specific gravity test to obtain the density of the silt;

[0061] S5, judging whether dredging is required according to the thickness and density of the silt.

[0062] In the above-mentioned schematic embodiment, the method for detecting siltation in the foundation trench of a immersed tube tunnel by the paving method is to install an RTK receiver on the detection platform for GPS positioning, thereby ensuring that the detection platform can accurately move to the detection point; the sealing membrane 2 is controlled by the sealing lifting wire 3, and no diving operation is required, which simplifies the operation process and reduces the cost of manpower and equipment; and ensures that the thickness and density of the siltation sample can be accurately obtained, thereby avoiding the data distortion caused by the eddy current phenomenon in the existing siltation box method; compared with the multi-beam measurement method, it is not affected by the turbidity of the water body and provides more reliable detection data; according to the data analysis of thickness and density, it is determined whether siltation is needed, thereby providing reliable data support for the construction management of the immersed tube tunnel. In summary, the method for detecting siltation in the foundation trench of an immersed tube tunnel by the paving method in the embodiment of the present invention can simultaneously detect the siltation of scouring and falling siltation, and can improve the efficiency and data accuracy of the detection of siltation in the foundation trench of an immersed tube tunnel.

[0063] In some embodiments, in step S1, the time and detection points that need to be detected include: one detection on the 7th day after the foundation trench of the immersed pipe segment is finely excavated and before the stone dumping, and each pipe segment is detected at a detection point; one detection on the 15th day and the 7th day after the stone vibration and before the crushed stone is leveled, and each pipe segment is detected at a detection point; one detection on the 7th day, the 5th day, the 3rd day and the 1st day after the crushed stone is leveled and before the pipe segment is sunk, and each pipe segment is detected at a detection point; the slope surface of the foundation trench is detected once on the 15th day before the crushed stone is leveled, the 7th day before the pipe segment is sunk, and after extreme weather. Through the specific detection time arrangement and the selection of detection points, the siltation dynamics of the foundation trench can be grasped in real time during the construction process, and silt removal measures can be taken in time to ensure the quality and safety of the construction. This embodiment not only improves the accuracy and reliability of siltation detection, but also provides a scientific basis for decision-making during the construction process.

[0064] In some embodiments, in step S5, the density is greater than 1.26 g / cm 3 The thickness of the siltation is h1, and the density is more than 1.15g / cm 3The thickness of the back silt is h2, and dredging is carried out when any of the following conditions are met: when the back silt thickness h1 obtained by any test after the precision excavation of the foundation trench of the submerged pipe segment and before the stone dumping is greater than 20cm, dredging is carried out; when the back silt thickness h1 obtained by any test after the stone vibration density and before the crushed stone leveling is greater than 10cm, or h2 is greater than 30cm, dredging is carried out; when the back silt thickness h1 obtained by any test after the crushed stone leveling and before the pipe segment is sunk is greater than 4cm, or h2 is greater than 10cm, dredging is carried out; when the back silt thickness h1 obtained by any monitoring of the slope surface of the foundation trench is greater than 40cm, dredging is carried out. Deciding whether to carry out dredging operations according to different construction stages and the conditions for detecting the back silt density and thickness can not only improve the accuracy and efficiency of back silt detection, but also ensure that dredging measures are taken in time at each key node of construction, which is conducive to controlling the construction quality and safety and preventing the impact of back siltation on the progress and quality of the project.

[0065] Furthermore, in step S1, multiple detection points are selected for detection of siltation at each foundation trench; in step S3, the average value of multiple detection points is taken as the detection value of the thickness of the siltation at that location; in step S4, siltation samples at multiple detection points are taken for specific gravity test, and the average value of the siltation density at each detection point is taken as the detection value of the siltation density at that location. By selecting multiple detection points for detection at each foundation trench and taking the average value as the detection result, the representativeness and accuracy of the data can be improved, thereby more comprehensively reflecting the siltation situation.

[0066] In some embodiments, in step S4, a large-diameter long pipette piston syringe is used to collect the sludge sample from above the sampling tube 1 through the bracket 103, and generally 100 ml is extracted.

[0067] In some embodiments, in step S2, the sampler is lowered by gravity of the counterweight 102. When the bottom of the sampler touches the bottom, it means that the sampler has completed the penetration sampling of the silt, and it is difficult for the sampler to continue to penetrate; in step S3, before measuring the thickness of each layer of silt in the sampler, the counterweight 102 should be removed to avoid the counterweight 102 interfering with the measurement. Through the gravity of the counterweight 102, the sampler is lowered more stably and efficiently, ensuring that the sampler can accurately penetrate the silt; after sampling, the counterweight 102 is removed to avoid the counterweight 102 affecting the measurement accuracy.

[0068] In some embodiments, in step S3, when measuring the thickness of each layer of silt in the sampler, when there is an interface between each layer of silt, the thickness of each layer of silt is directly measured; when each layer of silt is turbid and no interface exists, the thickness of each layer of silt is measured after the silt is left to stand until an interface appears. Generally speaking, when each layer of silt is turbid and no interface exists, the interface of each layer of silt can be observed after standing for 8 hours. The turbid silt is allowed to stand to produce an interface before the thickness is measured, which improves the accuracy and reliability of the measurement, especially when the turbidity is high.

[0069] In some embodiments, in step S1, the traction rope 4 is fixed to the top of the sampler to lower the sampler, and the hook 601 of the connector 6 and the diaphragm fixing member 5 are used to fix the sealing diaphragm 2 when the sampler is lowered; in step S2, after the sampler penetrates the silt and touches the bottom to complete the sampling, the traction rope 4 is relaxed, the hook 601 is separated from the diaphragm fixing member 5, and the positioning of the sealing diaphragm 2 is released. At this time, the sealing lifting lead 3 is lifted to pull the sealing diaphragm 2 so that the sealing diaphragm 2 moves to the bottom opening of the sampler; in step S3, the traction rope 4 is lifted to pull the sampler up. After the sampler touches the bottom, the traction rope 4 is relaxed, the hook 601 automatically separates from the diaphragm fixing member 5, and the positioning of the sealing diaphragm 2 is released, which simplifies the operation steps; at the same time, the sealing lifting lead 3 ensures that the opening at the bottom of the sampling tube 1 can be blocked in time to prevent sample leakage. After the traction rope 4 is lifted, the extraction of the sampler can be easily completed, which improves the detection efficiency and accuracy.

[0070] In some embodiments, the sealing lifting wire 3 is inserted into the lifting wire jacket 301, and a detachable fixing block 302 is installed at the top opening of the lifting wire jacket 301. In step S2, after the sealing lifting wire 3 is lifted, the opening at the top of the lifting wire jacket 301 is blocked by the fixing block 301, and the sealing lifting wire 3 is fixed at the same time. This embodiment can prevent the sealing lifting wire 3 from retracting, ensure that the sealing lifting wire 3 remains stable during the sampling process, and effectively improve the reliability and accuracy of the sampling operation.

[0071] Based on the above-mentioned method for detecting siltation in the foundation trench of immersed tube tunnel using the pre-laying method, Figure 2-Figure 6 As shown, the present invention also provides a sampler for silting back in the foundation trench of a pre-laid immersed tube tunnel, which adopts the above-mentioned method for detecting silting back in the foundation trench of a pre-laid immersed tube tunnel, and comprises a sampling tube 1, a sealing film 2 and a sealing lead wire 3; wherein the sampling tube 1 is used to accommodate the silting back sample of the foundation trench, and an opening is provided at the bottom of the sampling tube 1, such as Figure 3 As shown, a bracket 103 is fixed on the top; a sealing film 2 is arranged at the bottom of the sampling tube 1, and is used to seal the opening after sampling; one end of the sealing lead wire 3 is connected to the sealing film 2 through the bottom of the sampling tube 1, and the other end is controlled by the staff. When the sealing lead wire 3 is pulled up, the sealing lead wire 3 pulls the sealing film 2 to move and seal the opening.

[0072] In the above-mentioned schematic embodiment, the siltation sampler for the foundation trench of the immersed tube tunnel of the first-laid method ensures the accurate acquisition of the siltation sample by setting an opening at the bottom of the sampling tube 1 and sealing it with a sealing film 2, thereby avoiding the data distortion caused by the eddy current phenomenon in the traditional siltation box method; by setting the sealing lead wire 3, the operator can easily control the opening and closing of the sealing film 2 without diving operation, thereby reducing the difficulty and cost of operation; the sampler is suitable for two siltation situations of flushing and falling siltation, and can more comprehensively reflect the actual siltation situation in the foundation trench. Compared with the multi-beam measurement method, it is not affected by the turbidity of the water body and provides more accurate detection data; and it simplifies the siltation sampling process, reduces the dependence on diving equipment and professionals, thereby reducing the detection cost and improving the economic benefit. In summary, the sampler for siltation detection of the foundation trench of the immersed tube tunnel of the first-laid method in the embodiment of the present invention can significantly improve the efficiency and accuracy of siltation detection of the foundation trench of the immersed tube tunnel of the first-laid method, and provide reliable data support for the quality control of the immersed tube tunnel construction.

[0073] In some embodiments, Figure 2 As shown, the siltation sampling device for the tunnel foundation trench of the first-laid immersed tube method further includes a traction rope 4, one end of which is connected to the top bracket 103 of the sampling tube 1, and the other end of which is controlled by the staff to be retracted and released, and is used to lift or lower the sampling tube 1. The setting of the traction rope 4 facilitates the staff to lift or lower the sampling tube 1 by controlling the traction rope 4, thereby improving the flexibility and safety of the sampling process.

[0074] Furthermore, the length of the traction rope 4 is at least greater than the sampling depth of the detection point by 3 m.

[0075] In some embodiments, Figure 2 As shown, the siltation sampler for the submerged tunnel foundation trench of the first-laid method also includes a connector 6 and a membrane fixing member 5. One end of the connector 6 is connected to the traction rope 4, and the other end is provided with a hook 601. The hook 601 is connected to the membrane fixing member 5, and the end of the membrane fixing member 5 away from the hook 601 is connected to the sealing membrane 2. During the lowering process of the sampler, the hook 601 is connected to the membrane fixing member 5 to fix the position of the sealing membrane 2. When the bottom of the sampler touches the bottom, the traction rope 4 is relaxed, and the hook 601 is automatically separated from the membrane fixing member 5, releasing the fixing of the sealing membrane 2. Through the arrangement of the connector 6 and the membrane fixing member 5, the sealing membrane 2 is fixed and automatically separated during the lowering process of the sampler, which can ensure the smooth progress of the sampling process, simplify the operation process, and improve the accuracy and reliability of sampling.

[0076] In some embodiments, Figure 4As shown, the sampler for detecting the siltation of the foundation trench of the immersed tube tunnel by the first laying method also includes a diaphragm pull lead 7, and the diaphragm fixing part 5 is connected to the sealing diaphragm 2 through the diaphragm pull lead 7; a diaphragm fixing point 101 is provided at the bottom of the sampling tube 1, one end of the diaphragm pull lead 7 is fixed to the diaphragm fixing point 101, and the other end is connected to the sealing diaphragm 2 and the diaphragm fixing part 5 at the same time. When the hook 601 is automatically separated from the diaphragm fixing part 5, the sealing lifting lead 3 can pull the sealing diaphragm 2 to move and block the opening at the bottom of the sampling tube 1, and at the same time, the diaphragm pull lead 7 moves downward with the sealing diaphragm 2. When the diaphragm pull lead 7 is tightened, the diaphragm pull lead 7 and the sealing lifting lead 3 fix the sealing diaphragm 2 at the opening of the sampling tube 1. Through the setting of the diaphragm pull lead 7 and the diaphragm fixing point 101, the position of the sealing diaphragm 2 is effectively fixed during the sampling process, and the bottom opening of the sampling tube 1 is quickly blocked when necessary.

[0077] In some embodiments, Figure 2 As shown, the siltation sampling device for the submerged tunnel foundation trench of the first-laid method also includes a lifting wire fixing device for fixing the height of the sealing lifting wire 3. By setting the lifting wire fixing device, the height of the sealing lifting wire 3 can be effectively fixed to prevent the sealing lifting wire 3 from loosening or sliding during operation, thereby ensuring the stability and accuracy of the sampling process.

[0078] In some embodiments, Figure 6 As shown, the lifting wire fixing device includes a lifting wire sleeve 301 sleeved on the outer periphery of the sealing lifting wire 3 and a fixing block 302. The fixing block 302 is arranged at one end of the lifting wire sleeve 301 away from the sealing film 2, and is used to clamp the lifting wire sleeve 301 to fix the height of the sealing lifting wire 3. The fixing block 302 clamps the lifting wire sleeve 301 to fix the height of the sealing lifting wire 3, thereby preventing the sealing lifting wire 3 from retracting or sliding during the operation, thereby improving the reliability and accuracy of the sampling operation.

[0079] In some embodiments, Figure 3 As shown, the sealing film 2 is provided with a first lifting point 201 and a second lifting point 202, the first lifting point 201 and the second lifting point 202 are arranged opposite to each other, and the sealing lifting wire 3 is connected to the first lifting point 201 and the second lifting point 202 at the same time. Through the arrangement of the first lifting point 201 and the second lifting point 202, the sealing lifting wire 3 can evenly apply force to the sealing film 2, ensuring that the sealing film 2 is more secure when sealing the opening, and preventing leakage of the silted sample.

[0080] In some embodiments, Figure 2 As shown, a counterweight block 102 is provided at the bottom of the sampling tube 1 for pulling the sampling tube 1 to automatically fall. By setting the counterweight block 102, it can be ensured that the sampling tube 1 automatically falls and penetrates the silt during the placement process, thereby improving the convenience of the sampling operation.

[0081] In some embodiments, the sampling tube 1 is made of a transparent material. As an illustrative embodiment, the sampling tube 1 is made of a transparent high-strength acrylic material. The use of a transparent material facilitates observation and confirmation of the siltation sample in the sampling tube 1, and at the same time, facilitates measurement of the thickness of each layer of siltation, thereby improving the convenience and accuracy of the operation.

[0082] It is understandable that the size of the sampling tube 1 should be sufficient to accommodate multiple layers of silt, and a step for installing the counterweight 102 should be provided. As an illustrative embodiment, the sampling tube 1 has an inner diameter of 10 cm, a height of 1.0 m, a wall thickness of 5 mm, and a thickened section at the bottom; the wall thickness of the thickened section is 10 mm, the entire thickened section is arc-shaped, and a step for installing the counterweight 102 is provided on the upper part of the thickened section.

[0083] In some embodiments, the sealing film 2 is made of elastic material. As an illustrative embodiment, the sealing film 2 is made of high-strength rubber film, and the thickness of the sealing film 2 is 2-4 mm.

[0084] The application of the pre-laying immersed tube tunnel foundation trench siltation sampler in the above-mentioned embodiments can achieve both rapid sampling and accurate detection of the thickness and density of siltation. The other positive technical effects of the pre-laying immersed tube tunnel foundation trench siltation detection method in the above-mentioned embodiments are also applicable to the pre-laying immersed tube tunnel foundation trench siltation sampler, which will not be repeated here.

[0085] Through the description of multiple embodiments of the method for detecting siltation in the foundation trench of an immersed tube tunnel using the paving method and the sampler of the present invention, it can be seen that the method for detecting siltation in the foundation trench of an immersed tube tunnel using the paving method and the sampler of the present invention have at least one or more of the following advantages:

[0086] 1. The method for detecting siltation in the foundation trench of a pre-laid immersed tube tunnel provided by the present invention controls the opening and closing of the sealing membrane 2 by means of the sealing lifting wire 3, and does not require diving operation, thus simplifying the operation process and reducing the manpower and equipment costs;

[0087] 2. The pre-laying immersed tube tunnel foundation trench siltation detection method provided by the present invention can accurately obtain the thickness and density of the siltation sample, avoiding the data distortion caused by the eddy current phenomenon in the existing siltation box method; compared with the multi-beam measurement method, it is not affected by the turbidity of the water body and provides more reliable detection data;

[0088] 3. The pre-laying immersed tube tunnel foundation trench siltation sampler provided by the present invention ensures accurate acquisition of siltation samples by setting an opening at the bottom of the sampling tube 1 and sealing it with a sealing membrane 2, thereby avoiding data distortion caused by eddy current phenomena in the traditional siltation box method; through the setting of the sealing lifting wire 3, the operator can easily control the opening and closing of the sealing membrane 2 without diving operation, reducing the operating difficulty and cost.

[0089] Finally, it should be noted that: the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0090] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A method for detecting siltation in a foundation trench of a pre-laid immersed tube tunnel, characterized in that: The following steps are involved: S1, when testing is needed, install an RTK receiver on the testing platform, use GPS positioning to move the testing platform to the testing point; S2, lower the sampler to take samples, and after the sampling is completed, pull up the sealing lead of the sampler to pull the sealing film to seal the bottom opening of the sampler; S3, lift the sampler up to the water surface, keep the sampler upright, and measure the thickness of the silt in the sampler; S4, extracting the silt sample in the sampler to perform a specific gravity test to obtain the density of the silt; S5, judging whether dredging is required according to the thickness and density of the silt.

2. The method for detecting siltation in foundation trench of immersed tube tunnel by pre-laying method according to claim 1 is characterized in that: In step S1, the time and detection points that need to be detected include: The immersed tube segment foundation trench shall be inspected once on the 7th day after fine excavation and before rock dumping. Each segment shall be inspected at selected inspection points. The test is conducted once on the 15th day and the 7th day after the block stones are vibrated and compacted and before the crushed stones are leveled. The test points are selected for each pipe section. After the gravel is leveled and before the pipe section is placed, the test is conducted once on the 7th day, 5th day, 3rd day and 1st day respectively. Each pipe section is tested at a selected testing point. The slope of the foundation pit shall be inspected once on the 15th day before gravel leveling, on the 7th day before pipe section sinking, and after extreme weather.

3. The method for detecting siltation in a foundation trench of a pre-laid immersed tube tunnel according to claim 2, characterized in that: In step S5, the density is greater than 1.26 g / cm 3 The thickness of the siltation is h1, and the density is more than 1.15g / cm 3 The siltation thickness is h2, and silt removal is carried out when any of the following conditions are met: When the silt thickness h1 obtained in any test after the fine excavation of the immersed tube segment foundation trench and before the block filling is greater than 20cm, silt removal shall be carried out; When the thickness of siltation h1>10cm or h2>30cm is obtained in any test after the block is vibrated and before the crushed stone is leveled, silt removal shall be carried out; When the thickness of siltation h1>4cm or h2>10cm is obtained in any test after the gravel is leveled and before the pipe section is laid, silt removal shall be carried out; When the siltation thickness h1 obtained from any monitoring of the slope surface of the foundation trench is greater than 40 cm, silt removal is carried out.

4. The method for detecting siltation in a foundation trench of a pre-laid immersed tube tunnel according to claim 1, characterized in that: In step S3, when measuring the thickness of each layer of silt in the sampler, when there is an interface between each layer of silt, the thickness of the silt is directly measured; when each layer of silt is turbid and there is no interface, the silt is left to stand until an interface appears and then the thickness of the silt is measured.

5. The method for detecting siltation in foundation trench of immersed tube tunnel by pre-laying method according to claim 1, characterized in that: In step S1, a traction rope is used to fix the top of the sampler to lower the sampler, and the sealing membrane is fixed and positioned by using the hook of the connecting piece and the membrane fixing piece when the sampler is lowered; in step S2, after the sampler penetrates the silt and touches the bottom to complete the sampling, the traction rope is relaxed, the hook is separated from the membrane fixing piece, and the positioning of the sealing membrane is released. At this time, the sealing lifting lead is lifted to pull the sealing membrane to move the sealing membrane to the bottom opening of the sampler; in step S3, the traction rope is lifted to pull the sampler upward.

6. The method for detecting siltation in a foundation trench of a pre-laid immersed tube tunnel according to claim 5, characterized in that: The sealing lifting lead is passed through the lifting lead sleeve, and a detachable fixing block is installed at the top opening of the lifting lead sleeve. In step S2, after the sealing lifting lead is lifted, the opening at the top of the lifting lead sleeve is blocked by the fixing block, and the sealing lifting lead is fixed at the same time.

7. A siltation sampling device for a pre-laying immersed tube tunnel foundation trench, characterized in that: The method for detecting siltation in a foundation trench of an immersed tube tunnel using a pre-laying method as claimed in any one of claims 1 to 6 comprises: The sampling tube is used to hold the siltation sample of the foundation trench, and the bottom of the sampling tube is provided with an opening and the top is fixed with a bracket; A sealing film is provided at the bottom of the sampling tube and is used to seal the opening after sampling; One end of the sealing lead wire is connected to the sealing film through the bottom of the sampling tube, and the other end is controlled by the staff. When the sealing lead wire is pulled up, the sealing lead wire pulls the sealing film to move and seal the opening.

8. The siltation sampling device for the foundation trench of a pre-laid immersed tube tunnel according to claim 7 is characterized in that: It also includes a traction rope, one end of which is connected to the top bracket of the sampling tube, and the other end of which is controlled by the staff to be retracted and released, and is used to lift or lower the sampling tube.

9. The siltation sampling device for the foundation trench of a pre-laid immersed tube tunnel according to claim 8 is characterized in that: It also includes a connecting piece and a diaphragm fixing piece, one end of the connecting piece is connected to the traction rope, and the other end is provided with a hook, the hook is connected to the diaphragm fixing piece, and the end of the diaphragm fixing piece away from the hook is connected to the sealing diaphragm; during the lowering process of the sampler, the hook is connected to the diaphragm fixing piece to fix the position of the sealing diaphragm, and when the bottom of the sampler touches the bottom, the traction rope is loosened, the hook and the diaphragm fixing piece are automatically separated, and the sealing diaphragm is released.

10. The siltation sampling device for the foundation trench of a pre-laid immersed tube tunnel according to claim 7, characterized in that: It also includes a lead wire sleeve and a fixing block which are sleeved on the outer periphery of the sealing lead wire. The fixing block is arranged at one end of the lead wire sleeve away from the sealing film and is used to clamp the lead wire sleeve to fix the height of the lead wire.

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