Device and method for testing dynamic response of continuous sinking water of immersed tunnel pipe joint

Abstract

The invention belongs to the technical field of simulation of installation and control of an offshore large floating structure, and particularly relates to a device and a method for testing dynamic response of continuous sinking water of a pipe joint of an immersed tunnel. According to the invention, the cooperative control technology of pipe joint immersion and mooring positioning is applied to the pool model test method of pipe joint continuous immersion, the control of the negative buoyancy of the pipe joint is realized by using a ballast water sump remote controller in the model test, and the cooperative control of a hoisting cable and a mooring positioning cable of the pipe joint is carried out by using a servo control system. The full-flow continuous simulation of the immersed tube section immersion operation is realized; cooperative control adjustment of cable lifting and releasing and mooring and positioning is conducted under the still water condition, the feasibility of the system control technology is verified, the influence of the hydrodynamic environment on dynamic response during continuous pipe joint sinking operation is studied, and a reference basis is provided for formulating and optimizing an immersed tunnel pipe joint sinking installation scheme.

Description

Technical Field

[0001] The present invention belongs to the technical field of simulation of the installation and control of large offshore floating structures, and particularly relates to an experimental device and method for the hydrodynamic response of continuous sinking of immersed tunnel segments, which is an experimental device and method for measuring the hydrodynamic response of large immersed tunnel segments during dynamic sinking. Background Art

[0002] During the design and construction of cross-sea immersed tunnels, the sinking and positioning process of immersed tunnel segments is the most critical and dangerous, which is directly related to the installation accuracy and operation safety of the immersed tunnel segments. Especially in complex marine environments such as wind, waves, and currents, during the hoisting process of the immersed tunnel segment by the installation barge, a multi-floating body coupling response system is formed under the connection and restraint of hoisting cables, positioning cables, mooring cables, etc. Its hydrodynamic response problem is still one of the most complex scientific problems in current ocean engineering, and physical model tests are the most direct and effective method to solve this problem.

[0003] For the hydrodynamic response test of the immersed tunnel segment - installation barge system, the current experimental devices are divided into two types: one is to ignore the influence of the movement of the installation barge, simulate the installation barge through a fixed support, and study the hydrodynamic response of the tunnel segment - installation barge system at a certain sinking depth. Due to the coupling effect between the installation barge and the tunnel segment, it is applicable to immersed tunnel projects with weak wave action; the other is to consider both the tunnel segment and the installation barge as floating bodies, and study the coupling effect between multiple floating bodies of the tunnel segment - installation barge system, which can be applicable to cross-sea immersed tunnel projects under open sea wave conditions, but all of the above are for a certain sinking depth condition.

[0004] In fact, during the installation process of the tunnel segment, the dynamic response of the entire sinking system has significant non-linear characteristics. Especially when the immersed tunnel is in the state of accelerating sinking and decelerating braking, different from the stable hoisting stage of uniform sinking, the sudden load on the hoisting cable will cause the entire system to exhibit discontinuous and rapidly changing non-steady characteristics. At the same time, deep water, heavy loads, and harsh marine environments will make the dynamic response of the tunnel segment more intense, and the force change of the sinking equipment more significant. The existing experimental techniques focus on the influence of fixed hoisting depth and marine dynamic parameters on the dynamic response of the hoisting system, ignoring the continuity of the sinking installation, and unable to truly reflect the non-steady characteristics of the entire hoisting system, thus it is difficult to meet the requirements of the full-process simulation of the system dynamic response in engineering practice.

[0005] During the continuous sinking process of the immersed tube segment, in addition to releasing the lifting cable to make the segment sink smoothly, the mooring and positioning cables of the segment need to be adjusted simultaneously to achieve the goals of movement restraint and precise positioning of the segment. However, there is a matching problem between the lifting cable and the mooring and positioning cables during this process. This is because the lifting cable has a linear relationship with the sinking depth of the segment, while the mooring and positioning cables show complex non-linear conditions with the sinking depth of the segment. This is the key problem faced in simulating the continuous sinking of the segment. Currently, limited by experimental equipment conditions and measurement technologies at home and abroad, there is no test device and method applicable to the hydrodynamic response of large-scale immersed tube segments in immersed tube tunnels during continuous sinking. Summary of the Invention

[0006] The purpose of the present invention is to solve the problems proposed in the background technology and provide an experimental control system and hydrodynamic test method applicable to the continuous sinking operation of immersed tube segments in immersed tube tunnels. The present invention applies the cooperative control technology of segment sinking and mooring and positioning to the pool model test method of continuous segment sinking. In the model test, a remote controller for the ballast water tank is used to control the negative buoyancy of the segment, and a servo control system is used to cooperatively control the lifting cable and the mooring and positioning cables of the segment to achieve a full-process continuous simulation of the sinking operation of the immersed tube segment; the adjustment of the cooperative control of the lifting cable and the mooring and positioning cables is carried out under static water conditions and the feasibility of the system control technology is verified, and the influence of the hydrodynamic environment on the dynamic response during the continuous sinking operation of the segment is studied, providing a reference basis for the formulation and optimization of the installation plan of the immersed tube segment in the immersed tube tunnel.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A test device for the hydrodynamic response of continuous sinking of immersed tube segments in an immersed tube tunnel, the test device includes a test pool 1, an installation barge model 2, an immersed tube segment model 3, a segment lifting control system, a segment mooring and positioning control system, a segment ballast water control system, and a measurement system.

[0009] A wave maker 11 and an axial flow pump group are provided in the test pool 1; the wave maker is controlled by a wave maker controller to generate target waves; the axial flow pump group is controlled by a flow controller to simulate water flow, and a return water corridor is provided at the bottom of the test pool 1. Combining with the return water corridor at the bottom of the pool, a target flow velocity flow field is generated in the test area; a wave dissipation facility 12 composed of a porous medium energy dissipation net is arranged around the test pool 1 to dissipate the incident waves and reflected waves.

[0010] The installation barge model 2 includes two installation barges, a segment lifting cable winch 21 and a segment mooring and positioning cable winch 22; the segment lifting cable winch 21 and the segment mooring and positioning cable winch 22 are fixed on the upper surface of the installation barge, and the installation barge is moored to the seabed mooring anchor block 5 through the installation barge model mooring cable 43 to carry out mooring restraint on the installation barge model;

[0011] The described immersed tube segment model 3 includes a tube segment, a ballast water tank a31, a ballast water tank b32, and a cable guide 33; a ballast water tank a31 and a ballast water tank b32 are arranged vertically in the middle of the tube segment to realize the sinking operation of the immersed tube segment, and a plurality of cable guides 33 are arranged on the upper surface of the tube segment; the installation barge is connected to the tube segment through the tube segment hoisting cable 41, and the tube segment is located below the installation barge.

[0012] The total capacity of the ballast water tank a31 and the ballast water tank b32 corresponds to the target negative buoyancy, and exhaust pumps are provided in both the ballast water tank a31 and the ballast water tank b32.

[0013] The material of the inner cabin of the immersed tube segment model 3 is plexiglass.

[0014] The described tube segment hoisting control system is composed of a servo controller a, a tube segment hoisting cable winch 21, and a tube segment hoisting cable 41. By adjusting the rotation speed of the tube segment hoisting cable winch 21 through the servo controller a, the length of the tube segment hoisting cable 41 is controlled, and parameters such as the hoisting depth, speed, and acceleration of the tube segment are controlled.

[0015] The described tube segment mooring and positioning control system is composed of a servo controller b, a tube segment mooring and positioning cable winch 22, a tube segment mooring and positioning cable 42, and a cable guide 33; the tube segment mooring and positioning cable 42 is led out by the tube segment mooring and positioning cable winch 22, passes through the cable guide 33 installed on the immersed tube segment mold 3, and is connected to the seabed mooring anchor block 5; by adjusting the rotation speed of the tube segment mooring and positioning cable winch 22 through the servo controller b, the positioning and mooring constraints of the continuously sunk tube segment are realized.

[0016] The described tube segment ballast water control system is composed of a remote controller and the ballast water tank a31 and the ballast water tank b32. The remote controller remotely opens the hatch doors and exhaust valves of the ballast water tank a31 and the ballast water tank b32 to adjust the states of the two ballast water tanks.

[0017] The described measurement system includes a non-contact six-degree-of-freedom motion measurement system 6, a cable force measurement system 4, and a wave and water flow measurement system.

[0018] The described non-contact six-degree-of-freedom motion measurement system 6 measures the six-degree-of-freedom motion information of the center-of-gravity positions of the installation barge model 2 and the immersed tube segment model 3 through a non-contact six-degree-of-freedom motion measuring instrument.

[0019] The described cable force measurement system 4 measures the force conditions of the tube segment hoisting cable 41, the tube segment mooring and positioning cable 42, and the installation barge model mooring cable 43 through S-type underwater tension sensors.

[0020] The described wave and water flow measurement system measures wave height, flow velocity, flow direction, etc. within the test range through a wave height sensor and an ADV flowmeter.

[0021] An experimental method for the dynamic response of continuous sinking of a immersed tube tunnel segment uses the above experimental device and includes the following steps:

[0022] The first step, test preparation and device installation:

[0023] First, according to the test site conditions, clarify the effective test area of the test pool. Through the adjustment of the wave-making controller and the flow-making controller, use the wave-making machine 11 and the axial flow pump group to generate the expected wave and water flow dynamic environment in the test area, record the relevant control parameters and store the corresponding wave surface and flow velocity data to achieve the calibration of the dynamic environment before the hydrodynamic test;

[0024] Then, use the grid method to establish a local coordinate system in the test area, determine the multiple mooring positions of the tunnel segment and the installation barge by means of fixed-point lofting, and install the seabed mooring anchor block 5;

[0025] At the same time, to realize the retraction and release of the lifting cable 41 of the tunnel segment and the mooring positioning cable 42 of the tunnel segment and the cable guiding, install the lifting cable winch 21 of the tunnel segment and the mooring positioning cable winch 22 of the tunnel segment on the installation barge of the installation barge model 2, and install the cable guide 33 on the tunnel segment of the immersed tube tunnel segment model 3;

[0026] Finally, connect the tunnel segment and the installation barge through the lifting cable 41 of the tunnel segment, and use the mooring cable 43 of the installation barge model and the mooring positioning cable 42 of the tunnel segment for mooring restraint.

[0027] The second step: Coordinated control technology adjustment and verification of tunnel segment sinking and mooring positioning:

[0028] First, fill the test pool 1 with water to the test water depth D. While keeping the lengths of all mooring cables 43 of the installation barge model the same, adjust the initial tension of all mooring cables 43 of the installation barge model to 10% of the cable breaking force limit to ensure the mooring restraint of the installation barge during the adjustment and verification process;

[0029] Then, open the hatch of the ballast tank a31 or the ballast tank b32 through the remote controller, fill the ballast tank of the ballast tank a31 or the ballast tank b32 with ballast water, so that the tunnel segment enters the negative buoyancy state, and the negative buoyancy F 负浮力 The calculation formula is as shown in formula (1):

[0030] F 负浮力 =G 管节 +G 压载水 -F 浮 (1)

[0031] In the formula, G 管节It is the gravity of the immersed tube section, G 压载水 It is the gravity of the ballast water in the ballast tank, F 浮 It is the buoyancy force when the tube section is completely immersed. At this time, the length of the lifting cable 41 of the tube section is adjusted to l s0 , and the force on the lifting cable 41 of the tube section is the negative buoyancy F 负浮力 of 1 / n, where n is the number of the lifting cables 41 of the tube section; adjust the mooring and positioning cable winch 22 of the tube section, and adjust the force on all the mooring and positioning cables 42 of the tube section to 10% of the breaking force limit of the cable. At this time, the length of the mooring and positioning cable is l m0 ; where:

[0032] l s0 = c0(2)

[0033] l m0 = a0 + b0 + c0(3)

[0034] In the formula, a0 is the distance from the anchor point of the mooring and positioning cable of the tube section to the corner guide of the tube section at the initial time t0, b0 is the distance from the middle cable guide on the tube section to the corner guide, and c0 is the distance from the mooring and positioning winch to the top surface of the tube section at the initial time t0; at the moment t0, the tube section is just immersed, and the top surface of the tube section is flush with the still water surface.

[0035] Subsequently, adjust the lifting cable winch 21 of the tube section through the servo controller a and adjust the mooring and positioning cable winch 22 of the tube section through the servo controller b, so that the corresponding lifting cable length l s (t) and the mooring and positioning cable length l m (t) satisfy the following relationship:

[0036] l s (t) = l s0 + d(t) = c0 + d(t)(4)

[0037] l m (t) = a(t) + b0 + c(t)(5)

[0038] a(t) 2 = [a0 * cosβ(t)] 2 + [D - d(t)] 2 (6)

[0039] b(t) = b0(7)

[0040] c(t) = c0 + d(t)(8)

[0041] Wherein, a(t) is the distance from the mooring and positioning cable anchor point of the pipe section to the corner guide of the pipe section at time t, b(t) is the distance from the intermediate cable guide on the pipe section to the corner guide, c(t) is the distance from the mooring and positioning winch to the top surface of the pipe section at time t, β(t) is the angle between the mooring and positioning cable and the horizontal plane at time t, and D is the test water depth.

[0042] The cable payout speed v of the corresponding pipe section hoisting cable winch 21 s should satisfy the following relationship:

[0043] v s ×t = l s (t) - l s0 = d(t)(9)

[0044]

[0045] The cable payout speed v of the corresponding pipe section mooring and positioning cable winch 22 m should satisfy the following relationship:

[0046]

[0047] According to the above relationships, calculate the cable payout speeds of the pipe section hoisting cable winch 21 and the pipe section mooring and positioning cable winch 22 corresponding to different pipe section sinking speeds.

[0048] Under static water conditions, verify the matching relationship among the calculated pipe section sinking speed, the cable payout speed v of the hoisting cable s , and the cable payout speed v of the mooring and positioning cable m , that is, the three satisfy the relationships in formulas (10) and (11), and check whether the forces on the hoisting cable and the mooring and positioning cable can remain unchanged and are not affected by the pipe section hoisting operation. If there are obvious changes in the cable forces, the cable payout speeds of the hoisting cable winch and the mooring and positioning cable winch need to be adjusted according to the results of the verification test until the forces on the hoisting cable and the mooring and positioning cable are basically unchanged, which can be used as the continuous hoisting control parameters for the corresponding pipe section sinking speed.

[0049] Step 3: Influence of hydrodynamic environment on the system dynamic response during continuous pipe section hoisting operation

[0050] First, complete the test of the dynamic parameters of the immersed tube - installation barge system: after the test device is installed and debugged and the ballast water is filled, conduct the free decay tests of the pipe section and the installation barge in different movement directions respectively; calculate the natural periods and damping coefficients of each movement degree of freedom of the sinking system based on the static water decay curve;

[0051] Then, conduct the continuous sinking test of the pipe section under a specific hydrodynamic environment: input the desired wave parameters and water flow parameters through the wave-making controller and the current-making controller to form a stable flow field and wave surface in the test area of the test pool 1. Subsequently, through the verified pipe section lifting cable 41 and the pipe section mooring and positioning cable 42 collaborative control system, control the continuous lifting of the pipe section at the specified lifting speed; monitor and record the six-degree-of-freedom movement amounts of the pipe section and the installation barge and the force-bearing process of the cable through the non-contact six-degree-of-freedom movement measurement system 6 and the cable force measurement system 4, analyze and obtain the variation laws of the movement responses of the immersed tube pipe section and the installation barge and the force on the cable during the continuous lifting process with respect to the hydrodynamic parameters, and put forward corresponding optimization suggestions for the continuous lifting operation of the pipe section.

[0052] Advantages of the present invention:

[0053] The test device of the present invention is novel in design, consumes less manpower in the test process, the floating weight ratio of the test device can be adjusted, and it has the advantages of high test process efficiency and low test cost. Compared with the traditional test methods of fixed installation barges or fixed sinking depths, the test method of the present invention is more in line with the dynamic properties of large-size pipe sections during offshore installation under continuous lifting operations, and can reasonably capture and simulate the sudden loads and mechanical property changes of the lifting equipment during continuous lowering operations, and then realize in-depth research on the dynamic response coupling mechanism of the entire immersed tube - installation barge system, which is beneficial to improving the levels of dynamic analysis, response prediction, and attitude control of the actual engineering immersed tube lifting operation. Description of the drawings

[0054] Figure 1 It is a schematic diagram of the process and control process of the continuous sinking test of the immersed tube pipe section;

[0055] Figure 2 It is a schematic diagram of the installation barge model;

[0056] Figure 3 It is a schematic diagram of the pipe section model;

[0057] Figure 4 It is a schematic diagram of the cable layout and installation of the continuous sinking test of the pipe section;

[0058] Figure 5 It is a schematic diagram of the continuous sinking process of the pipe section;

[0059] Figure 6 It is a force relationship diagram.

[0060] In the figure: 1 wave and current test pool; 2 installation barge model; 3 pipe section model; 4 cable force measurement system; 5 seabed mooring anchor block; 6 non-contact six-degree-of-freedom movement measurement system;

[0061] 11 wave-making machine; 12 wave-dissipating facilities;

[0062] 21 Pipe joint hoisting cable winch; 22 Pipe joint mooring and positioning cable winch;

[0063] 31 Pipe joint ballast tank a; 32 Pipe joint ballast tank b; 33 Cable guide;

[0064] 41 Pipe joint hoisting cable; 42 Pipe joint mooring and positioning cable; 43 Installation barge model mooring cable. Specific implementation mode

[0065] The following further illustrates the specific implementation mode of the present invention in combination with the accompanying drawings and technical solutions.

[0066] As Figures 1-5 shown, an experimental device for the dynamic response of continuous sinking of immersed tunnel pipe joints includes a wave and current experimental pool 1, an installation barge model device 2, an immersed tunnel pipe joint model 3, a cable system, a pipe joint hoisting control system, a pipe joint mooring and positioning control system, a pipe joint ballast water control system, and a measurement system. Among them: The wave and current experimental pool 1 is used to generate waves and water currents, simulating the main environmental loads on the immersed tunnel and the installation barge - wave loads and ocean current loads. The installation barge model device 2 mainly includes an installation barge, a pipe joint hoisting cable winch 21, and a pipe joint mooring and positioning cable winch 22. The immersed tunnel pipe joint model 3 mainly includes a pipe joint, a ballast water tank a 31, a ballast water tank b 32, and a cable guide 33. The cable system mainly includes a pipe joint hoisting cable 41, a pipe joint mooring and positioning cable 42, and an installation barge model mooring cable 43. The controllers of the cable winches and ballast water tanks mainly include a servo controller a of the pipe joint hoisting cable winch 21, a servo controller b of the pipe joint mooring and positioning cable winch 22, and a ballast water tank remote controller. The measurement system includes a non - contact six - degree - of - freedom motion measurement system 6, a cable force measurement system 4, and a wave and water current measurement system. The non - contact six - degree - of - freedom motion measurement system 4 and the cable force measurement system 4 are used to synchronously and real - time collect the motion response of the pipe joint / sinking barge, and the time - history curves of the tensions of the hoisting cable, mooring cable, and positioning cable.

[0067] The experimental pool 1 is used to generate the required wave and water current conditions, simulating the actual hydrodynamic environment of ocean waves and tidal currents in the engineering sea area during the continuous sinking process of the immersed tunnel pipe joint. The simulation of waves is achieved by controlling the motion of the wave maker 11 through the wave maker controller to generate the target waves; a wave dissipation facility 12 composed of a porous medium energy dissipation net is arranged around the experimental pool to dissipate the incident waves and reflected waves and avoid the influence of the reflection of the pool side wall; the simulation of water currents is achieved by controlling the axial flow pump group through the flow controller, combined with the return pipe gallery at the bottom of the pool, to generate the target flow velocity field in the experimental area.

[0068] The installation barge model 2 includes two installation barges, which serve as the main operating platforms for the immersion of tunnel segments. The winches 21 for hoisting the tunnel segments and the winches 22 for mooring and positioning the tunnel segments are fixed on the installation barges and are connected to the seabed mooring anchor blocks 5 through the mooring cables 43 of the installation barge model to impose mooring constraints on the installation barge model.

[0069] The immersed tunnel segment model 3, to ensure the airtightness requirements of the immersed tunnel segment model, is different from the traditional test models made of concrete. The inner cabin of the tunnel segment model is provided with plexiglass inner cabins. At the same time, to realize the immersion operation of the immersed tunnel segment, ballast water tanks a 31 and ballast water tanks b 32 are arranged in the middle of the tunnel segment.

[0070] The control system for hoisting the tunnel segment consists of a servo controller a, a hoisting cable winch 21, and a hoisting cable 41 for the tunnel segment. By adjusting the rotation speed of the hoisting cable winch 21 through the servo controller a, the length of the hoisting cable is controlled, and parameters such as the hoisting depth, speed, and acceleration of the tunnel segment are controlled.

[0071] The control system for mooring and positioning the tunnel segment consists of a servo controller b, a mooring and positioning cable winch 22 for the tunnel segment, a mooring and positioning cable 42 for the tunnel segment, and a cable guide 33. The mooring and positioning cable 42 for the tunnel segment is led out by the mooring and positioning cable winch 22 for the tunnel segment, and after passing through the cable guide 33 installed on the immersed tunnel segment model 3, it is connected to the anchor block 5 at the bottom of the seabed. By adjusting the rotation speed of the mooring and positioning cable winch 22 for the tunnel segment through the servo controller b, the positioning and mooring constraints of the continuously immersed tunnel segment are realized.

[0072] The control system for the ballast water of the tunnel segment consists of a remote controller, ballast water tanks a 31, and ballast water tanks b 32. The remote controller remotely opens the hatch doors and exhaust valves of the ballast water tanks to adjust the states of the two ballast water tanks.

[0073] The test device further includes:

[0074] The non-contact six-degree-of-freedom motion measurement system 6 is used to measure the six-degree-of-freedom motion information of the center-of-gravity positions of the installation barge model 2 and the immersed tunnel segment model 3.

[0075] The cable force measurement system 4 measures the forces on the hoisting cable 41 for the tunnel segment, the mooring and positioning cable 42 for the tunnel segment, and the mooring cable 43 of the installation barge model through S-type underwater tension sensors.

[0076] The wave and water flow measurement system measures the wave height, flow velocity, flow direction, etc. within the test range through wave height sensors and ADV current meters.

[0077] A test device method for the hydrodynamic response of continuous immersion of tunnel segments of a immersed tube tunnel adopts the above test device and includes the following steps:

[0078] The first step, test preparation and device installation:

[0079] First, according to the test site conditions, clarify the effective test area of the test pool. Through the adjustment of the wave-making controller 11 and the current-making controller 14, generate the expected wave and water flow dynamic environment in the test area by the wave-making machine and the axial flow pump group, record the relevant control parameters and store the corresponding wave surface and flow velocity data, so as to realize the calibration of the dynamic environment before the hydrodynamic test;

[0080] Then, adopt the grid method to establish a local coordinate system in the test area, determine multiple mooring positions of the pipe section and the installation barge by the method of fixed-point lofting, and install the seabed mooring anchor block 5;

[0081] At the same time, in order to realize the retraction and release of the pipe section lifting and lowering cable 41 and the pipe section mooring and positioning cable 42 and the cable guiding, install the lifting and lowering cable winch 21 and the pipe section mooring and positioning cable winch 22 at Figure 3 the specified positions on the two installation barge models, and install the cable guide 33 at Figure 4 the specified position on the immersed tube pipe section model;

[0082] Finally, connect the immersed tube pipe section and the installation barge through the pipe section lifting and lowering cable 41, and use the installation barge model mooring cable 43 and the pipe section mooring and positioning cable 42 for mooring restraint. It should be noted that in order to ensure the balance and symmetry of the mooring restraint, in this embodiment, the 4 pipe section lifting and lowering cables 41, the 4 pipe section mooring and positioning cables 42, and the 8 installation barge model mooring cables 43 respectively maintain the same length, and the installation and cable guiding methods of the pipe section mooring and positioning cables 42 are consistent with the actual project, such as Figure 5 .

[0083] The second step: Adjustment and verification of the coordinated control technology for pipe section sinking and mooring positioning:

[0084] The core point of the coordinated control technology for pipe section sinking and mooring positioning lies in ensuring that there is no significant change in the cable force due to the uncoordinated retraction and release operations of the pipe section lifting and lowering cable and the mooring and positioning cable. That is, to solve the control problem of coordinating the cable payout speed of the pipe section lifting and lowering cable and the mooring and positioning cable when the pipe section has different sinking speeds under static water conditions. Among them, the length ls of the pipe section lifting and lowering cable 41 has a linear relationship with the sinking depth d, but the relationship between the length lm of the pipe section mooring and positioning cable 42 and the sinking depth d has a complex geometric conversion relationship. The force relationship is as Figure 6 shown.

[0085] First, fill the test pool 1 with water to the test water depth D. While keeping the lengths of the 8 installation barge model mooring cables 43 the same, adjust the initial tension of all the installation barge model mooring cables 43 to 10% of the cable breaking force limit to ensure the mooring restraint of the installation barge during the adjustment and verification process;

[0086] Then, open the ballast tank A31 or ballast tank B32 through the remote controller, fill the specified ballast tank, so that the immersed tube section enters the negative buoyancy state (the gravity of the tube section is greater than the buoyancy), and the negative buoyancy F 负浮力 The calculation formula is as shown in Equation (1):

[0087] F 负浮力 = G 管节 + G 压载水 - F 浮 (1)

[0088] In the formula, G 管节 is the gravity of the immersed tube section, and G 压载水 is the gravity of the ballast water in the specified ballast tank. At this time, the lengths of the four pipe section suspension cables 41 are adjusted to l s0 , and the force on the pipe section suspension cable 41 is 1 / 4 of the negative buoyancy F 负浮力 of the pipe section; adjust the pipe section mooring and positioning cable winch 22 to adjust the force on the four pipe section mooring and positioning cables 42 to 10% of the cable breaking force limit. At this time, the length of the pipe section mooring and positioning cable 42 is l m0 ; where:

[0089] l s0 = c0 (2)

[0090] l m0 = a0 + b0 + c0 (3)

[0091] Subsequently, through the servo controller A, adjust the pipe section suspension cable winch 21 and the pipe section mooring and positioning cable winch 22, so that the corresponding pipe section suspension cable length l s (t) and the pipe section mooring and positioning cable length l m (t) when the pipe section suspension depth is d(t) satisfy the following relationship:

[0092] l s (t)= l s0 + d(t)= c0 + d(t) (4)

[0093] l m (t)= a(t)+ b(t)+ c(t) (5)

[0094] a(t) 2 =(a0 * cosβ) 2 + [D - d(t)] 2 (6)

[0095] b(t)= b0 (7)

[0096] c(t)= c0 + D - d(t) (8)

[0097] The corresponding cable payout speed v of the suspension cable winch 21s The following relationship should be satisfied:

[0098] v s ×t = l s (t) - l s0 = d(t)(9)

[0099]

[0100] The cable payout speed v of the pipe joint mooring and positioning cable winch 22 corresponding to it m should satisfy the following relationship:

[0101]

[0102] According to the above relationship, calculate the cable payout speeds of the pipe joint hoisting cable winch 21 and the pipe joint mooring and positioning cable winch 22 corresponding to different pipe joint sinking speeds.

[0103] Under static water conditions, for the calculated pipe joint sinking speed, the cable payout speed v of the hoisting cable s , and the cable payout speed v of the mooring and positioning cable m Verify the matching relationship among them, that is, the three satisfy the relationships in formulas (10) and (11), and check whether the forces on the hoisting cable and the mooring and positioning cable can remain unchanged and are not affected by the pipe joint hoisting operation. If there is a clear change in the cable force, it is necessary to appropriately adjust the cable payout speeds of the hoisting cable winch and the mooring and positioning cable winch according to the results of the verification test until the forces on the hoisting cable and the mooring and positioning cable are basically unchanged, which can be used as the continuous hoisting control parameters for the corresponding pipe joint sinking speed.

[0104] Step 3: Influence of hydrodynamic environment on the system dynamic response during continuous pipe joint hoisting operation

[0105] First of all, it is necessary to complete the test of the dynamic parameters of the immersed tube - installation barge system: after the test model and device are installed and debugged and the ballast water is filled, carry out the free decay tests of the immersed tube and the installation barge in different movement directions respectively; that is, when the floating body is excited by an external force with a single degree of freedom in static water, there will be a displacement in this degree of freedom, and then under the action of external constraints and the restoring force of the water body, it will gradually decay until it stops. The movement process during this process is measured by a non - contact floating body movement measurement system, and the natural period and damping coefficient of each movement degree of freedom of the sinking system are calculated based on the static water decay curve;

[0106] Then, conduct the continuous sinking test of the pipe section under a specific hydrodynamic environment: input the desired wave parameters and water flow parameters through the wave-making and current-making controllers to form a stable flow field and wave surface in the test area of the test pool. Subsequently, through the verified collaborative control system of the pipe section lifting cable 41 and the mooring and positioning cable 42, control the pipe section to be continuously lifted at the specified lifting speed; monitor and record the six-degree-of-freedom movement of the immersed tube and the installation barge and the force on the cable during the process through the non-contact six-degree-of-freedom movement measurement system 6 and the cable force measurement system 4, analyze the variation law of the movement response of the immersed tube pipe section and the installation barge and the force on the cable with the hydrodynamic parameters during the continuous lifting process, and put forward corresponding optimization suggestions for the continuous lifting operation of the pipe section.

[0107] The test device and method for the hydrodynamic response of continuous sinking of the pipe section of an immersed tube tunnel provided by the present invention have the following remarkable advantages:

[0108] (1) The present invention proposes a collaborative control technology for pipe section sinking and mooring and positioning that simulates the continuous sinking process of the pipe section of an immersed tube tunnel. By adjusting the cable payout speed of the lifting cable and the mooring and positioning cable through a servo controller, the smoothness and force balance during the pipe section sinking process are satisfied. The present invention applies the collaborative control technology of pipe section sinking and mooring and positioning to the simulation of the continuous sinking of the immersed tube pipe section, especially for the key processes of accelerating sinking at the initial stage of sinking, stable lifting in the middle stage, and decelerating braking at the final stage. Through the hydrodynamic test of continuous sinking of the pipe section, the dynamic response characteristics of continuous sinking of the immersed tube are deeply explored.

[0109] (2) In the present invention, through the servo controller, the lifting cable winch and the mooring and positioning cable winch driven by the stepping motor are controlled, and automatic operation can be carried out according to the set cable payout speeds of the lifting cable and the mooring and positioning cable, and the control accuracy can reach ±1 mm.

[0110] (3) By designing the immersed tube pipe section into an outer shell and an inner shell cabin, and respectively using concrete and plexiglass materials with densities similar to those of the actual engineering materials for integrated design and production, the contradiction in the traditional test method that cannot take into account both the structural strength and density of the pipe body and the precise waterproofing of the pipe body is solved; at the same time, partition cabins are arranged in the inner shell cabin to simulate the ballast water tank, which can conveniently adjust the negative buoyancy of the pipe section, that is, the structural response characteristics corresponding to multiple negative buoyancies can be tested in the same set of test devices. The application of the electronic water stop valve to remotely control the filling of the ballast water solves the problem of difficult manual valve opening in the deep pool experiment under the condition of large water depth, and can simulate the continuous filling process of the ballast water.

[0111] (4) The non-contact floating body motion measurement system is applied to realize the synchronous measurement of the motion quantities of the immersed tube segment and the installation barge. The multi-channel underwater tension acquisition system is applied to realize the real-time synchronous measurement of multiple groups of lifting cables, mooring cables and positioning cables. The acquisition module and the synchronization module are set in the test data synchronous acquisition system, which can realize the accurate synchronous acquisition of various types of test data, ensuring the feasibility of the coupled dynamic response analysis of the overall system of immersed tube - lifting cable - installation barge.

Claims

1. An experimental device for the dynamic response of continuous sinking of immersed tunnel segments, characterized in that The test device includes a test water tank (1), an installation barge model (2), a immersed tube segment model (3), a tube segment lifting control system, a tube segment mooring and positioning control system, a tube segment ballast water control system, and a measurement system; In the test water tank (1), there are a wave maker (11) and an axial flow pump group; the wave maker is controlled by a wave maker controller to generate target waves; the axial flow pump group is controlled by a flow controller to simulate water flow. A return water corridor is provided at the bottom of the test water tank (1). Combining with the return water corridor at the bottom of the water tank, a target velocity flow field is generated in the test area; A wave dissipation facility (12) composed of a porous medium energy dissipation net is arranged around the test water tank (1) to dissipate incident waves and reflected waves; The installation barge model (2) includes two installation barges, a tube segment lifting cable winch (21), and a tube segment mooring and positioning cable winch (22); the tube segment lifting cable winch (21) and the tube segment mooring and positioning cable winch (22) are fixed on the upper surface of the installation barge. The installation barge is connected to the seabed mooring anchor block (5) through the installation barge model mooring cable (43) to anchor and restrain the installation barge model; The immersed tube segment model (3) includes a tube segment, a ballast water tank a (31), a ballast water tank b (32), and a cable guide (33); The middle of the tube segment is provided with a vertically arranged ballast water tank a (31) and a ballast water tank b (32) to realize the sinking operation of the immersed tube segment. A plurality of cable guides (33) are arranged on the upper surface of the tube segment; The installation barge is connected to the tube segment through the tube segment lifting cable (41), and the tube segment is located below the installation barge; The tube segment lifting control system is composed of a servo controller a, a tube segment lifting cable winch (21), and a tube segment lifting cable (41). By adjusting the rotation speed of the tube segment lifting cable winch (21) through the servo controller a, the length of the tube segment lifting cable (41) is controlled, and the control of parameters such as the lifting depth, speed, and acceleration of the tube segment is realized; The tube segment mooring and positioning control system is composed of a servo controller b, a tube segment mooring and positioning cable winch (22), a tube segment mooring and positioning cable (42), and a cable guide (33); The tube segment mooring and positioning cable (42) is led out by the tube segment mooring and positioning cable winch (22), passes through the cable guide (33) installed on the immersed tube segment mold 3, and is connected to the seabed mooring anchor block (5); By adjusting the rotation speed of the tube segment mooring and positioning cable winch (22) through the servo controller b, the positioning and mooring restraint of the continuously sinking tube segment are realized; The tube segment ballast water control system is composed of a remote controller and a ballast water tank a (31) and a ballast water tank b (32). The remote controller remotely opens the hatch doors and exhaust valves of the ballast water tank a (31) and the ballast water tank b (32) to adjust the states of the two ballast water tanks; The measurement system includes a non-contact six-degree-of-freedom motion measurement system (6), a cable force measurement system (4), and a wave and water flow measurement system; The described non-contact six-degree-of-freedom motion measurement system (6) measures the six-degree-of-freedom motion information of the center-of-gravity positions of the installation barge model (2) and the immersed tube segment model (3) through a non-contact six-degree-of-freedom motion measuring instrument; The described cable force measurement system (4) measures the forces on the pipe section lifting cable (41), the pipe section mooring and positioning cable (42), and the installation barge model mooring cable (43) through S-type underwater tension sensors; The described wave and water flow measurement system measures the wave height, flow velocity, and flow direction within the test range through a wave height sensor and an ADV flow velocity meter.

2. The test device for the dynamic response of continuous sinking of a immersed tunnel segment according to claim 1, wherein, The total capacities of the described ballast water tanks a (31) and b (32) correspond to the target negative buoyancy, and exhaust pumps are provided in both the ballast water tank a (31) and the ballast water tank b (32).

3. The test device for the continuous sinking water dynamic response of the immersed tunnel segment according to claim 1, characterized in that, The material of the inner cabin of the described immersed tube segment model (3) is plexiglass.

4. An experimental method for the hydrodynamic response of continuous sinking of an immersed tube tunnel segment, using the experimental device described in any one of claims 1-3, includes the following steps: The first step, experimental preparation and device installation: First, according to the test site conditions, clarify the effective test area of the test pool. Through the adjustment of the wave-making controller and the current-making controller, generate the expected wave and water flow dynamic environment in the test area through the wave-making machine (11) and the axial flow pump group, record the relevant control parameters, and store the corresponding wave surface and flow velocity data to achieve the calibration of the dynamic environment before the hydrodynamic test; Then, use the grid method to establish a local coordinate system in the test area, determine the multiple mooring positions of the pipe section and the installation barge by means of fixed-point lofting, and install the seabed mooring anchor blocks (5); At the same time, to realize the retraction and release of the pipe section lifting cable (41) and the pipe section mooring and positioning cable (42) and the cable guiding, install the pipe section lifting cable winch (21) and the pipe section mooring and positioning cable winch (22) on the installation barge of the installation barge model (2), and install the cable guide (33) on the pipe section of the immersed tube segment model (3); Finally, connect the pipe section and the installation barge through the pipe section lifting cable (41), and use the installation barge model mooring cable (43) and the pipe section mooring and positioning cable (42) for mooring restraint; The second step: Adjustment and verification of the coordinated control technology for pipe section sinking and mooring and positioning: First, fill the test pool (1) with water to the test water depth D. While keeping the lengths of all the installation barge model mooring cables (43) the same, adjust the initial tension of all the installation barge model mooring cables (43) to 10% of the cable breaking force limit to ensure the mooring restraint of the installation barge during the adjustment and verification process; Then, open the hatch of the ballast tank a (31) or ballast tank b (32) through the remote controller, fill the ballast tank a (31) or ballast tank b (32) with ballast water, so that the pipe section enters the negative buoyancy state, and the negative buoyancy F 负浮力 The calculation formula is as shown in Equation (1): F 负浮力 = G 管节 + G 压载水 - F 浮 (1) where G 管节 is the gravity of the immersed tube segment, and G 压载水 is the gravity of the ballast water in the designated ballast tank. F 浮 is the buoyancy force when the tube segment is completely immersed. At this time, the length of the hoisting cable (41) of the tube segment is adjusted to l s0 , and the force on the hoisting cable (41) of the tube segment is 1 / n of the negative buoyancy force F 负浮力 of the tube segment, where n is the number of hoisting cables (41) of the tube segment. Adjust the mooring positioning cable winch (22) of the tube segment to adjust the force on all mooring positioning cables (42) of the tube segment to 10% of the ultimate breaking force of the cable. At this time, the length of the mooring positioning cable is l m0 ; Wherein: l s0 ＝c0(2) l m0 = a0 + b0 + c0(3) In the formula, a0 is the distance from the anchor point of the pipe section mooring and positioning cable to the corner point guide of the pipe section at the initial moment t0, b0 is the distance from the middle cable guide on the pipe section to the corner point guide, and c0 is the distance from the mooring and positioning winch to the top surface of the pipe section at the initial moment t0; at the moment t0, the pipe section is just submerged, and the top surface of the pipe section is flush with the still water surface; Subsequently, adjust the pipe section hoisting cable winch (21) through servo controller a and adjust the pipe section mooring positioning cable winch (22) through servo controller b, so that the hoisting cable length l s (t) and the mooring positioning cable length l m (t) satisfy the following relationship: l s l(t) = l s0 c(t) = c0 + d(t) (4) l m (t) = a(t) + b0 + c(t) (5) a(t) 2 = [a0 * cosβ(t)] 2 + [D - d(t)] 2 (6) b(t) = b0(7) c(t) = c0 + d(t)(8) Wherein, a(t) is the distance from the mooring and positioning cable anchor point of the pipe section at time t to the corner guide of the pipe section, b(t) is the distance from the intermediate cable guide on the pipe section to the corner guide, c(t) is the distance from the mooring and positioning winch to the top surface of the pipe section at time t, β(t) is the angle between the mooring and positioning cable and the horizontal plane at time t, and D is the test water depth; The cable payout speed v of the corresponding pipe joint hoisting cable winch (21) s shall satisfy the following relationship: v s ×t = l s (t) - l s0 = d(t)(9) The cable payout speed v of the corresponding pipe joint mooring positioning cable winch (22) m shall satisfy the following relationship: According to the above relationships, the cable payout speeds of the pipe section lifting cable winch (21) and the pipe section mooring and positioning cable winch (22) corresponding to different pipe section sinking speeds are calculated; Under static water conditions, verify the matching relationship among the calculated pipe joint sinking speed, the payout speed v of the lifting cable, s and the payout speed v of the mooring and positioning cable, m that is, the three satisfy the relationships in Formulas (10) and (11), and check whether the forces on the lifting cable and the mooring and positioning cable can remain unchanged without being affected by the pipe joint lifting operation; if there are obvious changes in the cable forces, the payout speeds of the lifting cable winch and the mooring and positioning cable winch need to be adjusted according to the results of the verification test until the forces on the lifting cable and the mooring and positioning cable basically remain unchanged, which can be used as the continuous lifting control parameters at the corresponding pipe joint sinking speed; Step 3: Influence of hydrodynamic environment on the system dynamic response during continuous pipe section lifting operation First, the dynamic parameters of the immersed tube - installation barge system need to be measured: After the test device is installed and debugged and the ballast water is filled, the free decay tests of the pipe section and the installation barge in different moving directions are carried out respectively; The natural periods and damping coefficients of each degree of freedom of the sinking system are deduced based on the still - water decay curve; Then, carry out the continuous pipe section sinking test under a specific hydrodynamic environment: By inputting the desired wave parameters and water flow parameters through the wave - making controller and the current - making controller, a stable flow field and wave surface are formed in the test area of the test pool (1). Subsequently, through the verified coordinated control system of the pipe section lifting cable (41) and the pipe section mooring and positioning cable (42), the pipe section is controlled to be continuously lifted at the specified lifting speed; The six - degree - of - freedom movements of the pipe section and the installation barge and the process of cable force are monitored and recorded by the non - contact six - degree - of - freedom motion measurement system (6) and the cable force measurement system (4). The variation laws of the motion responses of the immersed tube pipe section and the installation barge and the cable force during the continuous lifting process with respect to the hydrodynamic parameters are analyzed, and corresponding optimization suggestions for the continuous pipe section lifting operation are put forward.

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