A method for installing a shallow section sea drainage pipe

Abstract

The present invention discloses a method for installing a shallow section sea drainage pipe, including a preparation process and a construction process; the preparation process includes a preparation step before the pipeline is launched and a pontoon device positioning step; in the preparation step before the pipeline is launched, a concave flange and a convex flange are welded one-to-one at both ends of the pipeline segment, and a flange blind plate is fixed at the outer end of the concave flange and the outer end of the convex flange respectively; in the pontoon device positioning step, the first pontoon device to the fourth pontoon device are anchored and positioned in sequence from front to back at a certain interval, the first pontoon device and the fourth pontoon device are used to remove the flange blind plates at both ends of the pipeline segment one-to-one, and the second pontoon device and the third pontoon device are used for the installation of the pipeline segment; the construction process includes steps one to ten. The present invention uses four pontoon devices to install the pipeline segment in a pre-excavated foundation trench on the shallows, without the need for matching ships, and can effectively solve the installation problem of long-distance shallow section sea drainage pipes, and has less impact on the surrounding sea areas.

Description

Technical Field

[0001] The invention relates to an installation method of a shallow section sea discharge pipe. Background Art

[0002] Sewage bay discharge is a form of sewage discharge in which the sewage outlet is located in the bay and discharged into the sea. At present, sewage sea discharge pipelines are gradually developing from shallow sea to deep sea. The installation of deep sea sewage pipelines is generally long and the installation process is difficult.

[0003] The sea discharge pipe from the sewage treatment plant is connected by the land section pipe and the sea section pipe. The land section pipe needs to be buried on land to the coast, and then connected to the sea section pipe through the shoal section pipe. The installation location of the shoal section pipe is located in the shallow water area on the shore side, and the shoal section is generally longer. In addition, ships cannot enter the shoal section at low tide, and the pipeline sinking and installation construction must be carried out during the tide. The available window period is short and the construction process control requirements are high. Therefore, it is necessary to design an unconventional ship machinery equipment to install the shoal section sea discharge pipe and study the corresponding installation method. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a method for installing a shallow section sea discharge pipe. It uses four special buoyancy devices to install the pipeline segments in a pre-excavated foundation trench on the shallows, which can effectively solve the installation problem of long-distance shallow section sea discharge pipes.

[0005] The object of the present invention is achieved as follows: a method for installing a shallow section sea discharge pipe, using four buoyancy devices to assemble multiple pipe segments into a shallow section sea discharge pipe in a pre-excavated foundation trench in the shallow section;

[0006] Each of the pontoon devices comprises two pontoon bodies, a hoisting bracket, a hoisting device, two traction winches, a pedal, two front anchor windlasses and two rear anchor windlasses; wherein,

[0007] The two buoyancy boxes are arranged in parallel with a spacing greater than the diameter of the sea discharge pipe, so that a pipeline channel is provided between the two buoyancy boxes;

[0008] The hoisting bracket includes two steel columns, two cross beams and two longitudinal beams; the two steel columns are fixed one by one to the middle of the top surface of the two buoyancy boxes; the two cross beams are spanned between the top surfaces of the two steel columns at intervals; the two longitudinal beams are spanned between the middle of the top surfaces of the two cross beams, and the spacing between the two longitudinal beams is adapted to the diameter of the sea discharge pipe;

[0009] The sling comprises two sets of pulley groups, two hoisting winches and a pipe wire rope; the fixed pulleys of the two sets of pulley groups are respectively hung on the middle part of the bottom surface of the two longitudinal beams of the hoisting bracket through the upper hooks on the top; the two hoisting winches are installed on the top surfaces of the two floating boxes in a one-to-one manner, and the free ends of the wire ropes on the two hoisting winches are connected to the free ends of the ropes wound on the two sets of pulley groups in a one-to-one manner; the two ends of the pipe wire rope are connected to the lower hooks below the movable pulleys of the two sets of pulley groups in a one-to-one manner;

[0010] Two traction winches are installed one by one on the rear top surfaces of the two pontoon bodies;

[0011] The pedal is connected across the rear top surfaces of the two buoyancy boxes;

[0012] Two front anchor machines are installed one by one on the front top surfaces of the two buoyancy boxes and connected to the two front anchors one by one;

[0013] Two rear anchor machines are installed one by one on the rear top surfaces of the two buoyancy boxes and connected to the two rear anchors one by one;

[0014] The installation method of the shallow section sea discharge pipe of the present invention includes a preparation process and a construction process;

[0015] The preparation process includes the pipeline pre-launch preparation steps and the pontoon device positioning steps;

[0016] The preparation steps before launching the pipeline are carried out at the pipe assembly site and include the following processes:

[0017] Step 1: fix the convex flange and the concave flange on the pipe head and the pipe tail of each pipe segment in a one-to-one correspondence; a flange ring is radially extended from the outer end surface of the butt end of the convex flange and the concave flange; a connecting plate is radially extended from the outer peripheral surface of the butt end of the concave flange and the convex flange, and a plurality of connecting holes are radially evenly arranged on the surface of the connecting plate; after the tenon of the convex flange is inserted into the tenon groove of the concave flange, the convex flange and the concave flange are fastened and connected through a flange ring provided on the rear end surface of the flange ring and a plurality of sets of bolt assemblies provided one by one between the plurality of bolt holes on the flange ring and the plurality of connecting holes on the connecting plate;

[0018] Step 2: Install a blind flange plate on the outer end face of the concave flange of each pipeline segment, and also install a blind flange plate on the outer end face of the convex flange of each pipeline segment through a flange ring;

[0019] Step three: a manhole is opened at the seaward end of each pipe segment near the flange and the manhole is sealed with a manhole sealing plate;

[0020] Step 4: tie the first to sixth rope loops on each pipeline segment along the length direction, the first rope loop is close to the rear end of the first buoyancy device, the second rope loop and the third rope loop are close to the front end and rear end of the second buoyancy device one by one, the fourth rope loop and the fifth rope loop are close to the front end and rear end of the third buoyancy device one by one, and the sixth rope loop is close to the front end of the fourth buoyancy device; finally, tie three traction ropes on each pipeline segment, each traction rope is composed of two traction ropes, the first traction rope is connected between the third rope loop and the first rope loop by a buckle, the second traction rope is connected between the fifth rope loop and the third rope loop by a buckle, and the third traction rope is connected between the sixth rope loop and the fifth rope loop by a buckle;

[0021] The steps of positioning the buoyancy device include the following steps:

[0022] Process 1: The first pontoon device to the fourth pontoon device are hoisted to the sea by a crane ship at high tide, and then the first pontoon device to the fourth pontoon device are towed to the position to be installed of the pipeline segment by an anchoring boat, and the first pontoon device to the fourth pontoon device are anchored and positioned in sequence from front to back at a certain interval, and then the first pontoon device and the second pontoon device, the second pontoon device and the third pontoon device, and the third pontoon device and the fourth pontoon device are connected with nylon ropes;

[0023] Step 2: tying and pulling a plurality of buoys at the front inner corners and the rear inner corners of the two buoy bodies of the first buoy device to the fourth buoy device;

[0024] The construction process includes the following steps:

[0025] Step 1: Two anchor boats tow a pipeline segment. The front anchor boat pulls the pipe head of the pipeline segment through the cable, and the rear anchor boat controls the pipe tail of the pipeline segment through the cable and maintains the same speed as the front anchor boat. When it is almost at the installation area, the front anchor boat slowly slows down to stop, and the rear anchor boat hovers the pipeline segment. After the pipeline segment basically stops and approaches the fourth pontoon device, the small boat delivers the cable connected to the front anchor boat to the fourth pontoon device, and the rear anchor boat always stabilizes the pipeline segment at the rear before the pipeline segment enters the first pontoon device to the fourth pontoon device.

[0026] Step 2: Two anchor boats are stationed, and the rope end of the first towing rope connected to the first rope loop is untied by a small boat, and the rope end of the first towing rope is handed over to two towing winches on the fourth buoy device, and then the cable connected to the pipe head of the pipeline segment is untied;

[0027] Step 3: Use the two traction winches on the fourth buoyancy device to pull the first traction rope, introduce the pipeline segment into the pipeline channel of the fourth buoyancy device, until the pipe head of the pipeline segment is located in the middle of the pipeline channel of the third buoyancy device, then untie the rope head connecting the second traction rope and the third rope loop, and then connect the two rope heads of the second traction rope to the two traction winches of the fourth buoyancy device one by one, and untie the two rope heads of the first traction rope at the same time;

[0028] Step 4: Use the two traction winches on the fourth pontoon device to pull the second traction rope, and continue to introduce the pipeline segment from the pipeline channel of the third pontoon device into the pipeline channel of the second pontoon device until the pipe head of the pipeline segment is located in the middle of the pipeline channel of the second pontoon device, then untie the rope head connecting the third traction rope and the fifth rope loop, and then connect the two rope heads of the third traction rope to the two traction winches of the fourth pontoon device one by one, and untie the two rope heads of the second traction rope at the same time;

[0029] Step 5: The third traction rope is pulled by two traction winches on the fourth pontoon device to continue to introduce the pipeline segment into the pipeline channel of the second pontoon device until the second rope loop on the pipeline segment is located in the pipeline channel of the second pontoon device, and the operator on the second pontoon device hangs the rope tail of the fourth traction rope on the second rope loop, inserts the buckles of the two rope ends of the fourth traction rope into the nylon rope connected between the first pontoon device and the second pontoon device, and then the operator on the second pontoon device lifts the nylon rope to slide the two rope ends of the fourth traction rope onto the first pontoon device, and then the operator on the first pontoon device connects the two rope ends of the fourth traction rope to the two traction winches on the first pontoon device one by one;

[0030] Step 6: Use two traction winches on the first pontoon device to pull the fourth traction rope to pull the pipe head of the pipeline segment to the installation position, and then untie the cable connected between the pipe tail of the pipeline segment and the rear anchor boat;

[0031] Step 7: The operator on each buoyancy device first ties one end of a short rope to the corresponding rope loop, pulls the other end of the short rope, and then rotates the rope loop, so that one end of the short rope completes the bottom of the pipeline segment as the rope loop rotates; connects one end of the pipe hanging wire rope to the lower hook under the movable pulley of a set of pulley groups, and the other end of the pipe hanging wire rope is connected to one end of the short rope, and by pulling the other end of the short rope, the other end of the pipe hanging wire rope is connected to the lower hook under the movable pulley of another set of pulley groups, and finally unties the short rope to complete the connection between the pipe hanging wire rope and the pipeline segment;

[0032] Step 8: Remove the blind flanges at both ends of the pipeline segment, including the following steps:

[0033] In process 1, the pedals on the first pontoon device and the fourth pontoon device are unfolded, and the operator stands on the pedals on the first pontoon device and the fourth pontoon device and uses a pneumatic wrench to gradually remove the bolts on the flange blind plates installed at both ends of the pipeline segment from top to bottom one by one;

[0034] Step 2: Wrap the steel wire rope on a traction winch on the first pontoon device around a cross beam 22 and then hook it on the lifting lug on the top of the flange blind plate at the front end of the pipeline segment; Wrap the steel wire rope on a traction winch on the fourth pontoon device around a cross beam and then hook it on the lifting lug on the top of the flange blind plate at the rear end of the pipeline segment;

[0035] Step three: gradually lift the pipe hanging wire rope on the first pontoon device and the pipe hanging wire rope on the fourth pontoon device, and cooperate with the operator to remove the bolts fixed on the flange blind plates at both ends of the pipeline segment;

[0036] Step 4: Use a traction winch on the first pontoon device and a traction winch on the fourth pontoon device to move the two flange blind plates to the outside of the first pontoon device and the outside of the fourth pontoon device one by one and hang them, and hang a buoy on the first pontoon device and a buoy on the fourth pontoon device on the two flange blind plates one by one to reduce the weight of the flange blind plates, and the two flange blind plates will be recovered by a small boat at the subsequent high tide;

[0037] Step 5: First, hang the multiple buoys on the four pontoon devices on the corresponding rope loops on the pipeline segment, and lower the corresponding pipe-hanging wire ropes through the two hoisting winches on the four pontoon devices to gradually lower the pipeline segment. The operator on the fourth pontoon device removes the manhole sealing plate, and the air in the pipeline segment overflows through the manhole, so that the pipeline segment can be lowered horizontally;

[0038] Step 9, pipeline measurement, including measuring the following:

[0039] Content 1: After the previous pipeline segment is installed, the precise coordinates of the pipe head are tested and the floating ball is tied. When installing the next pipeline segment, the position of the pipe head is estimated first, and the coordinates of the first pontoon device are measured by the total station on the shore, and compared with the coordinates of the pipe head position of the previous pipeline segment that has been installed, and the installation position of the first pontoon device is adjusted;

[0040] Content 2: Set up a level in the axial direction of the sea pipe on the shore to observe the pipe-hanging wire ropes on the same side of the four buoyancy devices, and ensure that the pipe-hanging wire ropes on the same side of the four buoyancy devices are located on the same vertical plane by fine-tuning the anchor ropes of the four buoyancy devices;

[0041] Content 3: Measure the placement depth of the pipeline segment through the water lump and adjust the lowering length of the pipe hanging wire rope;

[0042] Step 10. After the pipeline segment is lowered to near the bottom of the base trench, under the command of the diver, the convex flange at the head of the pipeline segment is inserted into the concave flange at the tail of the previously installed pipeline segment, and the diver tightens the flange bolts between the flange ring and the concave flange.

[0043] The above-mentioned installation method of the shallow section sea discharge pipe, wherein the lifting bracket also includes two pairs of diagonal bracing rods; each pair of diagonal bracing rods is connected one by one between the top front side surface of the steel column and the front end top surface of the corresponding steel pontoon, and between the top rear side surface of the steel column and the rear end top surface of the corresponding steel pontoon.

[0044] In the above-mentioned installation method of the shallow section sea discharge pipe, one end of the pedal is installed on the inner side of the rear top surface of one buoyancy box body through a pin shaft, and the other end of the pedal is installed on the inner side of the rear top surface of another buoyancy box body through a positioning pin.

[0045] The above-mentioned method for installing the shallow section sea discharge pipe, wherein the construction process also includes:

[0046] Step 11, post-installation inspection: Check the tightening of the flange bolts through the underwater camera, take photos of the tightness of the joints inside the pipe through the manhole, and after confirming that it meets the design requirements, unhook the pipe hanging wire rope;

[0047] Step 12, post-installation processing: After each pipeline segment is installed, a hammer or a vertical pole is lowered on the first buoy device, and a diver places it on the pipe head of the pipeline segment. The coordinates of the pipe head are tested by the total station on shore, and a diver hangs a buoy on the pipe head.

[0048] The installation method of the shallow section sea discharge pipe of the present invention has the following characteristics: a shallow draft anchoring boat is used to tow the pipeline segment, and four special pontoon devices are used to install the pipeline segment in a pre-excavated foundation trench on the shallow section, which can effectively solve the installation problem of the long-distance shallow section sea discharge pipe and has less impact on the surrounding sea area; at the same time, through the weight reduction measures for the pipeline segment, the pipeline segment is always in a floating stability state, ensuring the structural safety of the pontoon device; there is no need for supporting ships, and the flange blind plates at both ends of the pipeline segment can be removed by themselves, which not only saves time and effort and construction costs, but also greatly reduces the damage to the pipeline and ensures the underwater installation quality of the pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a front view of a buoyancy device used in the installation method of the shallow section sea discharge pipe of the present invention;

[0050] Figure 2 yes Figure 1 Side view of

[0051] Figure 3 yes Figure 2 A top view of

[0052] Figure 4 It is a schematic diagram of the process 1 of the preparation step before the pipeline is launched into the water in the preparation process of the present invention;

[0053] Figure 5 It is a schematic diagram of the process 2 of the preparation step before the pipeline is launched into water in the preparation process of the present invention;

[0054] Figure 6 It is a schematic diagram of the process 4 of the preparation step before the pipeline is launched into water in the preparation process of the present invention;

[0055] Figure 7 It is a schematic diagram of the process 1 of the buoyancy device positioning step in the preparation process of the present invention;

[0056] Figure 8 It is a schematic diagram of step 1 in the construction process of the present invention;

[0057] Fig. 9 It is a schematic diagram of the step 2 in the construction process of the present invention;

[0058] Fig.10 It is a schematic diagram of step three in the construction process of the present invention;

[0059] Fig.11 It is a schematic diagram of the step 4 in the construction process of the present invention;

[0060] Fig.12 It is a schematic diagram of the step 5 in the construction process of the present invention;

[0061] Fig.13 It is a schematic diagram of the step six in the construction process of the present invention;

[0062] Fig.14 It is a schematic diagram of step seven in the construction process of the present invention. DETAILED DESCRIPTION

[0063] The present invention will be further described below in conjunction with the accompanying drawings.

[0064] See also Figures 1 to 3 The installation method of the shallow section sea discharge pipe of the present invention uses four buoyancy devices to assemble multiple pipeline segments 100 into the shallow section sea discharge pipe in a foundation trench pre-excavated on the shallows.

[0065] Each pontoon device includes two pontoon bodies 10 , a lifting bracket, a lifting device, two traction winches 4 , a pedal 5 , two front anchor windlasses 61 and two rear anchor windlasses 62 .

[0066] The two pontoons 10 are arranged in parallel with a spacing greater than the diameter of the sea discharge pipe, so that there is a pipeline channel between the two pontoons 10, and the width of the pipeline channel is 3m; the cross section of each pontoon 10 is a rectangle with a length×width=2.8m×2.2m, and the length of each pontoon 10 is 12m;

[0067] The lifting bracket includes two steel columns 21, two cross beams 22, two longitudinal beams 23 and two pairs of diagonal braces 24; wherein, the two steel columns 21 are fixed one by one on the middle of the top surface of the two pontoon bodies 10, and the steel columns 21 are made of steel pipes with an inner diameter of 1.22m and a length of 5.5m; the two cross beams 22 are spaced across the top surfaces of the two steel columns 21, the spacing between the two cross beams 22 is 0.8m, and the cross beams 22 are made of H-shaped steel; the two longitudinal beams 23 are spanned between the middle of the top surfaces of the two cross beams 22, and the spacing between the two longitudinal beams 23 is adapted to the diameter of the sea discharge pipe 100, and the longitudinal beams 23 are made of double-piece I-shaped steel; each pair of diagonal braces 24 is connected one by one between the top front side surface of the steel column 21 and the front end top surface of the corresponding steel pontoon 10 and between the top rear side surface of the steel column 21 and the rear end top surface of the corresponding steel pontoon 10.

[0068] The hoisting equipment includes two sets of pulley groups 31, two hoisting winches 33 and a pipe hanging wire rope 34; wherein, the fixed pulleys of the two sets of pulley groups 31 are respectively suspended one-to-one on the middle of the bottom surface of the two longitudinal beams 23 of the lifting bracket through the upper hooks 32 above; the two hoisting winches 33 are installed one-to-one on the top surfaces of the two floating boxes 10, and the free ends of the wire ropes on the two hoisting winches 33 are connected one-to-one with the free ends of the ropes wound on the two sets of pulley groups 31; the two ends of the pipe hanging wire rope 34 are connected one-to-one with the lower hooks 35 below the movable pulleys of the two sets of pulley groups 31.

[0069] The two traction winches 4 are mounted on the rear top surfaces of the two buoyancy boxes 10 in a one-to-one correspondence.

[0070] The pedal 5 is connected across the rear top surfaces of the two buoyancy boxes 10; one end of the pedal 5 is installed on the inner side of the rear top surface of one buoyancy box 10 through a pin 51, so that the pedal 5 can rotate around the pin 51, and the other end of the pedal 5 is installed on the inner side of the rear top surface of the other buoyancy box 10 through a positioning pin 52.

[0071] Two front anchor machines 61 are mounted one by one on the front top surfaces of the two buoyancy boxes 10 and are connected to the two front anchors one by one;

[0072] The two rear anchor machines 62 are mounted on the rear top surfaces of the two buoyancy boxes 10 in a one-to-one correspondence and are connected to the two rear anchors in a one-to-one correspondence.

[0073] See also Figures 4 to 14The installation method of the shallow section sea discharge pipe of the present invention includes a preparation process and a construction process;

[0074] The preparation process includes the pipeline pre-launch preparation steps and the pontoon device positioning steps;

[0075] The preparation steps before launching the pipeline are carried out at the pipe assembly site and include the following processes:

[0076] In step 1, the convex flange 1A and the concave flange 1B are fixed one by one on the pipe head and the pipe tail of each pipe segment 100; a flange ring 110 is radially extended from the outer end surface of the butt end of the convex flange 1A and the concave flange 1B; a connecting plate 120 is radially extended from the outer peripheral surface of the butt end of the concave flange 1B and the convex flange 1A, and a plurality of connecting holes are evenly distributed radially on the surface of the connecting plate 120; after the tenon of the convex flange 1A is inserted into the tenon groove of the concave flange 1B, the convex flange 1A is fastened to the concave flange 1B through a flange ring 1C provided on the rear end surface of the flange ring 110 and a plurality of sets of bolt assemblies 130 provided one by one between the plurality of bolt holes on the flange ring 1C and the plurality of connecting holes on the connecting plate 120 (see Figure 4 );

[0077] Step 2: Install a blind flange plate 1D on the outer end face of the concave flange 1B of each pipeline segment 100, and also install a blind flange plate 1D on the outer end face of the convex flange 1A of each pipeline segment 100 through a flange ring 1C (see Figure 5 ),

[0078] Step three, a manhole is opened at the seaward end of each pipeline segment 100 near the flange, and the manhole is sealed with a manhole sealing plate to facilitate inspection, processing and subsequent maintenance after the pipeline is installed;

[0079] Step 4: tie the first rope loop 2-1 to the sixth rope loop 2-6 on each pipeline segment 100 along the length direction. The first rope loop 2-1 is 0.5m away from the rear end of the first pontoon device 1-1. The second rope loop 2-2 and the third rope loop 2-3 are 0.5m away from the front end and the rear end of the second pontoon device 1-2 one by one. The fourth rope loop 2-4 and the fifth rope loop 2-5 are 0.5m away from the front end and the rear end of the third pontoon device 1-3 one by one. The sixth rope loop 2-6 is 0.5m away from the front end of the fourth pontoon device 1-4, which is convenient for operators to tie the first pontoon device 1-1 to the fourth pontoon device 1-1. On the device 1-4, a buoy is hung on the body of the pipeline segment 100; a shackle is respectively arranged at the top of the first rope loop to the sixth rope loop and at the same level as the manhole cover plate to facilitate underwater removal by divers; finally, three traction ropes are tied to each pipeline segment 100, each traction rope is composed of two traction ropes, the first traction rope 3-1 is connected between the third rope loop 2-3 and the first rope loop 2-1 by a buckle, the second traction rope 3-2 is connected between the fifth rope loop 2-5 and the third rope loop 2-3 by a buckle, and the third traction rope 3-3 is connected between the sixth rope loop 2-6 and the fifth rope loop 2-5 by a buckle (see Figure 6 );

[0080] The steps of positioning the buoyancy device include the following steps:

[0081] In the first process, the crane ship hoists the first to fourth pontoon devices to the sea at high tide, and then uses the anchoring boat to tow the first pontoon devices 1-1 to the fourth pontoon devices 1-4 to the position to be installed of the pipeline segment, and anchors the first pontoon devices 1-1 to the fourth pontoon devices 1-4 in sequence from front to back at a certain interval, and adjusts their respective positions by using the two front anchor windlasses 61 and the two rear anchor windlasses 61 on the first to fourth pontoon devices; when some soils cannot be anchored and fixed, the precast concrete blocks can be put into the water by the hooks provided on the anchoring boat at high tide. The first pontoon device 1-1 and the fourth pontoon device 1-4 are used to remove the flange blind plates at both ends of the pipeline segment in a one-to-one correspondence, and the second pontoon device 1-2 and the third pontoon device 1-3 are used to install the pipeline segment; and the first pontoon device 1-1 and the second pontoon device 1-2, the second pontoon device 1-2 and the third pontoon device 1-3, and the third pontoon device 1-3 and the fourth pontoon device 1-4 are connected with nylon ropes 20 to increase the integrity of the first pontoon device 1-1 to the fourth pontoon device 1-4 (see Figure 7 );

[0082] Step 2: tie and pull multiple buoys (not shown) from the front inner corners and rear inner corners of the two buoy bodies 10 of the first buoy device 1-1 to the front inner corners and rear inner corners of the two buoy bodies 10 of the fourth buoy device 1-4;

[0083] The construction process includes the following steps:

[0084] Step 1: Two anchoring boats or powered ships tow a pipeline segment 100. The front anchoring boat 4A tows the pipe head of the pipeline segment 100 through the cable, and the rear anchoring boat 4A controls the pipe tail of the pipeline segment 100 through the cable and maintains the same speed as the front anchoring boat 4A, which is used for braking and hovering at critical moments; when it is almost reaching the installation area, the front anchoring boat 4A slowly slows down to stop, and the rear anchoring boat 4A hovers the pipeline segment 100. After the pipeline segment 100 basically stops and approaches the fourth pontoon device 1-4, the small boat 4B delivers the cable connected to the front anchoring boat 4A to the fourth pontoon device 1-4, and the front anchoring boat 4A can leave. The rear anchoring boat 4A always stabilizes the pipeline segment 100 at the rear before the pipeline segment 100 enters the first pontoon device to the fourth pontoon device (see Figure 8 );

[0085] Step 2: The two anchor boats 4A are stationed, and the small boat 4B unties the rope end of the first traction rope 3-1 connected to the first rope loop 2-1, and hands the rope end of the first traction rope 3-1 to the two traction winches 4 on the fourth buoyancy device 1-4, and then unties the cable connected to the pipe head of the pipeline segment 100 (see FIG. Fig. 9 );

[0086] Step 3: The first traction rope 3-1 is pulled by the two traction winches 4 on the fourth pontoon device 1-4 to introduce the pipeline segment 100 into the pipeline channel of the fourth pontoon device 1-4 until the pipe head of the pipeline segment 100 is located in the middle of the pipeline channel of the third pontoon device 1-3, and then the rope ends connecting the second traction rope 3-2 and the third rope loop 2-3 are untied, and then the two rope ends of the second traction rope 3-2 are connected to the two traction winches 4 of the fourth pontoon device 1-4 one by one, and at the same time, the two rope ends of the first traction rope 3-1 are untied (see Fig.10 );

[0087] Step 4: Use the two traction winches 4 on the fourth pontoon device 1-4 to pull the second traction rope 3-2, and continue to introduce the pipeline segment 100 from the pipeline channel of the third pontoon device 1-3 into the pipeline channel of the second pontoon device 1-2, until the pipe head of the pipeline segment 100 is located in the middle of the pipeline channel of the second pontoon device 2-2, then untie the rope end connecting the third traction rope 3-3 and the fifth rope loop 2-5, and then connect the two rope ends of the third traction rope 3-3 to the two traction winches 4 of the fourth pontoon device 1-4 one by one, and at the same time untie the two rope ends of the second traction rope 3-2 (see Fig.11 );

[0088] Step 5: The third traction rope 3-3 is pulled by the two traction winches 4 on the fourth pontoon device 1-4 to continue to introduce the pipeline segment 100 into the pipeline channel of the second pontoon device 1-2 until the second rope loop 2-2 on the pipeline segment 100 is located in the pipeline channel of the second pontoon device 1-2. The operator on the second pontoon device 1-2 hangs the rope tail of the fourth traction rope 3-4 on the second rope loop 2-2, inserts the buckles of the two rope ends of the fourth traction rope 2-4 into the nylon rope 20 connected between the first pontoon device 1-1 and the second pontoon device 1-2, and then the operator on the second pontoon device 1-2 lifts the nylon rope 20 to slide the two rope ends of the fourth traction rope 3-4 onto the first pontoon device 1-1, and then the operator on the first pontoon device 1-1 connects the two rope ends of the fourth traction rope 3-4 to the two traction winches 4 on the first pontoon device 1-1 one by one (see Fig.12 );

[0089] Step 6: The fourth traction rope 2-4 is pulled by the two traction winches 4 on the first buoyancy device 1-1 to pull the pipe head of the pipeline segment 100 to the installation position, and then the cable connected between the pipe tail of the pipeline segment 100 and the rear anchoring boat 4A is untied (see Fig.13 );

[0090] Step 7: The operator on the first buoyancy device 1-1 first ties one end of a short rope 50 to the first rope loop 2-1, pulls the other end of the short rope 50, and then rotates the first rope loop 2-1, so that one end of the short rope 50 completes the bottom of the pipeline segment 100 as the first rope loop 2-1 rotates; connects one end of the pipe hanging wire rope 34 on the first buoyancy device 1-1 to the lower hook under the movable pulley of a set of pulley groups 31, and the other end of the pipe hanging wire rope 34 is connected to one end of the short rope 50, and by pulling the other end of the short rope 50, the other end of the pipe hanging wire rope 34 is connected to the lower hook under the movable pulley of another set of pulley groups 31, and finally unties the short rope 50 to complete the connection between the pipe hanging wire rope 34 on the first buoyancy device 1-1 and the pipeline segment 100 (see FIG. 1 ). Fig.14 ); The operator on the second pontoon device 1-2, the operator on the third pontoon device 1-3 and the operator on the fourth pontoon device 1-4 also connect their respective pipe hanging wire ropes 34 to the pipeline segment 100;

[0091] Step 8: Remove the blind flanges at both ends of the pipeline segment, including the following steps:

[0092] Step 1: unfold the pedal 5 on the first pontoon device 1-1 and the pedal 5 on the fourth pontoon device 1-4, and the operator stands on the pedal 5 of the first pontoon device 1-1 and the pedal 5 of the fourth pontoon device 1-4 and uses a pneumatic wrench to gradually remove the bolts on the flange blind plates 1D installed at both ends of the pipeline segment 100 from top to bottom one by one;

[0093] Step 2: Wrap the steel wire rope on a traction winch 4 on the first pontoon device 1-1 around a cross beam 22 and then hook it on the lifting lug on the top of the flange blind plate 1D at the front end of the pipeline segment 100; Wrap the steel wire rope on a traction winch 4 on the fourth pontoon device 1-4 around a cross beam 22 and then hook it on the lifting lug on the top of the flange blind plate 1D at the rear end of the pipeline segment 100;

[0094] Step three: gradually lift the pipe hanging wire rope 34 on the first pontoon device 1-1 and the pipe hanging wire rope 34 on the fourth pontoon device 1-4, and cooperate with the operator to remove the bolts fixed on the flange blind plates 1D at both ends of the pipeline segment 100;

[0095] Step 4: Use a traction winch 4 on the first pontoon device 1-1 and a traction winch 4 on the fourth pontoon device 1-4 to move the two flange blind plates 1D to the outside of the first pontoon device 1-1 and the outside of the fourth pontoon device 1-4 in a one-to-one correspondence, and hang a buoy on the first pontoon device 1-1 and a buoy on the fourth pontoon device 1-4 on the two flange blind plates 1D in a one-to-one correspondence to reduce the weight of the flange blind plates 1D, and the two flange blind plates 1D will be recovered by a small boat at the subsequent high tide;

[0096] Step five: first hang the multiple buoys tied to the four pontoon devices on the corresponding rope loops on the pipeline segment 100 to reduce the weight of the pipeline segment 100 after entering the water, so that the pipeline segment 100 is close to a floating stable state, and the pressure of the anchor ropes of each pontoon device when the pipeline segment 100 moves in the horizontal direction is reduced. At the same time, the buoys should have a little gravity to facilitate each pontoon device to adjust the position of the pipeline segment up and down through the lifting device, so as to facilitate the alignment of the pipeline segment; then, the two hoisting winches 32 on the four pontoon devices lower the corresponding pipe hanging wire ropes 34, gradually lower the pipeline segment 100, and the operator on the fourth pontoon device 1-4 removes the manhole sealing plate, and the air in the pipeline segment 100 overflows through the manhole, so that the pipeline segment 100 can be lowered horizontally;

[0097] Step 9, pipeline measurement, including measuring the following:

[0098] Content 1: After the previous pipeline segment is installed, the precise coordinates of the pipe head are tested and the floating ball is tied. When the next pipeline segment is installed, the position of the pipe head is estimated. At the same time, the coordinates of the first pontoon device are measured by the total station on the shore, and compared with the coordinates of the pipe head position of the previous pipeline segment that has been installed, and the installation position of the first pontoon device is adjusted;

[0099] Content 2: Set up a level in the axial direction of the onshore sea pipe to observe the pipe-hanging wire ropes on the same side of the four-buoy device, and ensure that the pipe-hanging wire ropes on the same side of the four-buoy device are located on the same vertical plane by fine-tuning the anchor ropes of the four-buoy device;

[0100] Content 3: Measure the placement depth of the pipeline segment through the water lump and adjust the lowering length of the pipe hanging wire rope;

[0101] Step 10: After the pipeline segment is lowered to the bottom of the base trench, the diver directs the convex flange at the head of the pipeline segment to be inserted into the concave flange at the tail of the previously installed pipeline segment, and the diver tightens the flange bolts between the flange ring and the concave flange;

[0102] Step 11, post-installation inspection: Check the tightening of the flange bolts through the underwater camera, take photos of the tightness of the joints inside the pipe through the manhole, and after confirming that it meets the design requirements, unhook the pipe hanging wire rope;

[0103] Step 12, post-installation processing: After each pipeline segment is installed, a hammer or a vertical pole is lowered on the first buoy device, and a diver places it on the pipe head of the pipeline segment. The coordinates of the pipe head are tested by the total station on shore, and a diver hangs a buoy on the pipe head.

[0104] The above embodiments are only used to illustrate the present invention, rather than to limit the present invention. Those skilled in the relevant technical field may make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also belong to the scope of the present invention and should be defined by the claims.

Claims

1. A method for installing a shallow section sea discharge pipe, using four buoyancy devices to assemble multiple pipe segments into a shallow section sea discharge pipe in a pre-excavated foundation trench in the shallow section; Each of the pontoon devices comprises two pontoon bodies, a hoisting bracket, a hoisting device, two traction winches, a pedal, two front anchor windlasses and two rear anchor windlasses; wherein, The two buoyancy boxes are arranged in parallel with a spacing greater than the diameter of the sea discharge pipe, so that a pipeline channel is provided between the two buoyancy boxes; The hoisting bracket includes two steel columns, two cross beams and two longitudinal beams; the two steel columns are fixed one by one to the middle of the top surface of the two buoyancy boxes; the two cross beams are spanned between the top surfaces of the two steel columns at intervals; the two longitudinal beams are spanned between the middle of the top surfaces of the two cross beams, and the spacing between the two longitudinal beams is adapted to the diameter of the sea discharge pipe; The sling comprises two sets of pulley groups, two hoisting winches and a pipe wire rope; the fixed pulleys of the two sets of pulley groups are respectively hung on the middle part of the bottom surface of the two longitudinal beams of the hoisting bracket through the upper hooks on the top; the two hoisting winches are installed on the top surfaces of the two floating boxes in a one-to-one manner, and the free ends of the wire ropes on the two hoisting winches are connected to the free ends of the ropes wound on the two sets of pulley groups in a one-to-one manner; the two ends of the pipe wire rope are connected to the lower hooks below the movable pulleys of the two sets of pulley groups in a one-to-one manner; Two traction winches are installed one by one on the rear top surfaces of the two pontoon bodies; The pedal is connected across the rear top surfaces of the two buoyancy boxes; Two front anchor machines are installed one by one on the front top surfaces of the two buoyancy boxes and connected to the two front anchors one by one; Two rear anchor machines are installed one by one on the rear top surfaces of the two buoyancy boxes and connected to the two rear anchors one by one; The installation method includes a preparation process and a construction process; it is characterized in that: The preparation process includes a pipeline pre-launch preparation step and a buoyancy device positioning step; The preparation steps before launching the pipeline are carried out at the pipe assembly site and include the following processes: Step 1: fix the convex flange and the concave flange on the pipe head and the pipe tail of each pipe segment in a one-to-one correspondence; a flange ring is radially extended from the outer end surface of the butt end of the convex flange and the concave flange; a connecting plate is radially extended from the outer peripheral surface of the butt end of the concave flange and the convex flange, and a plurality of connecting holes are radially evenly arranged on the surface of the connecting plate; after the tenon of the convex flange is inserted into the tenon groove of the concave flange, the convex flange and the concave flange are fastened and connected through a flange ring provided on the rear end surface of the flange ring and a plurality of sets of bolt assemblies provided one by one between the plurality of bolt holes on the flange ring and the plurality of connecting holes on the connecting plate; Step 2: Install a blind flange plate on the outer end face of the concave flange of each pipeline segment, and also install a blind flange plate on the outer end face of the convex flange of each pipeline segment through a flange ring; Step three: a manhole is opened at the seaward end of each pipe segment near the flange and the manhole is sealed with a manhole sealing plate; Step 4: tie the first to sixth rope loops on each pipeline segment along the length direction, the first rope loop is close to the rear end of the first buoyancy device, the second and third rope loops are close to the front and rear ends of the second buoyancy device one by one, the fourth and fifth rope loops are close to the front and rear ends of the third buoyancy device one by one, and the sixth rope loop is close to the front end of the fourth buoyancy device; finally, tie three traction ropes on each pipeline segment, each traction rope is composed of two traction ropes, the first traction rope is connected between the third rope loop and the first rope loop by a buckle, the second traction rope is connected between the fifth rope loop and the third rope loop by a buckle, and the third traction rope is connected between the sixth rope loop and the fifth rope loop by a buckle; The steps of positioning the buoyancy device include the following steps: Process 1: The first pontoon device to the fourth pontoon device are hoisted to the sea by a crane ship at high tide, and then the first pontoon device to the fourth pontoon device are towed to the position to be installed of the pipeline segment by an anchoring boat, and the first pontoon device to the fourth pontoon device are anchored and positioned in sequence from front to back at a certain interval, and then the first pontoon device and the second pontoon device, the second pontoon device and the third pontoon device, and the third pontoon device and the fourth pontoon device are connected with nylon ropes; Step 2: tying and pulling a plurality of buoys at the front inner corners and the rear inner corners of the two buoyancy boxes from the first buoyancy box device to the fourth buoyancy box device; The construction process includes the following steps: Step 1: Two anchor boats tow a pipeline segment. The front anchor boat pulls the pipe head of the pipeline segment through the cable, and the rear anchor boat controls the pipe tail of the pipeline segment through the cable and maintains the same speed as the front anchor boat. When it is almost at the installation area, the front anchor boat slowly slows down to stop, and the rear anchor boat hovers the pipeline segment. After the pipeline segment basically stops and approaches the fourth pontoon device, the small boat delivers the cable connected to the front anchor boat to the fourth pontoon device, and the rear anchor boat always stabilizes the pipeline segment at the rear before the pipeline segment enters the first pontoon device to the fourth pontoon device. Step 2: Two anchor boats are stationed, and the rope end of the first towing rope connected to the first rope loop is untied by a small boat, and the rope end of the first towing rope is handed over to two towing winches on the fourth buoy device, and then the cable connected to the pipe head of the pipeline segment is untied; Step 3: Use the two traction winches on the fourth buoyancy device to pull the first traction rope, introduce the pipeline segment into the pipeline channel of the fourth buoyancy device, until the pipe head of the pipeline segment is located in the middle of the pipeline channel of the third buoyancy device, then untie the rope head connecting the second traction rope and the third rope loop, and then connect the two rope heads of the second traction rope to the two traction winches of the fourth buoyancy device one by one, and untie the two rope heads of the first traction rope at the same time; Step 4: Use the two traction winches on the fourth pontoon device to pull the second traction rope, and continue to introduce the pipeline segment from the pipeline channel of the third pontoon device into the pipeline channel of the second pontoon device until the pipe head of the pipeline segment is located in the middle of the pipeline channel of the second pontoon device, then untie the rope head connecting the third traction rope and the fifth rope loop, and then connect the two rope heads of the third traction rope to the two traction winches of the fourth pontoon device one by one, and untie the two rope heads of the second traction rope at the same time; Step 5: The third traction rope is pulled by two traction winches on the fourth pontoon device to continue to introduce the pipeline segment into the pipeline channel of the second pontoon device until the second rope loop on the pipeline segment is located in the pipeline channel of the second pontoon device, and the operator on the second pontoon device hangs the rope tail of the fourth traction rope on the second rope loop, inserts the buckles of the two rope ends of the fourth traction rope into the nylon rope connected between the first pontoon device and the second pontoon device, and then the operator on the second pontoon device lifts the nylon rope to slide the two rope ends of the fourth traction rope onto the first pontoon device, and then the operator on the first pontoon device connects the two rope ends of the fourth traction rope to the two traction winches on the first pontoon device one by one; Step 6: Use two traction winches on the first pontoon device to pull the fourth traction rope to pull the pipe head of the pipeline segment to the installation position, and then untie the cable connected between the pipe tail of the pipeline segment and the rear anchor boat; Step 7: The operator on each buoyancy device first ties one end of a short rope to the corresponding rope loop, pulls the other end of the short rope, and then rotates the rope loop, so that one end of the short rope completes the bottom of the pipeline segment as the rope loop rotates; connects one end of the pipe hanging wire rope to the lower hook under the movable pulley of a set of pulley groups, and the other end of the pipe hanging wire rope is connected to one end of the short rope, and by pulling the other end of the short rope, the other end of the pipe hanging wire rope is connected to the lower hook under the movable pulley of another set of pulley groups, and finally unties the short rope to complete the connection between the pipe hanging wire rope and the pipeline segment; Step 8: Remove the blind flanges at both ends of the pipeline segment, including the following steps: In process 1, the pedals on the first pontoon device and the fourth pontoon device are unfolded, and the operator stands on the pedals on the first pontoon device and the fourth pontoon device and uses a pneumatic wrench to gradually remove the bolts on the flange blind plates installed at both ends of the pipeline segment from top to bottom one by one; Step 2: Wrap a wire rope on a traction winch on the first pontoon device around a cross beam and then hook it on the lifting lug on the top of the flange blind plate at the front end of the pipeline segment; Wrap a wire rope on a traction winch on the fourth pontoon device around a cross beam and then hook it on the lifting lug on the top of the flange blind plate at the rear end of the pipeline segment; Step three: gradually lift the pipe hanging wire rope on the first pontoon device and the pipe hanging wire rope on the fourth pontoon device, and cooperate with the operator to remove the bolts fixed on the flange blind plates at both ends of the pipeline segment; Step 4: Use a traction winch on the first pontoon device and a traction winch on the fourth pontoon device to move the two flange blind plates to the outside of the first pontoon device and the outside of the fourth pontoon device one by one and hang them, and hang a buoy on the first pontoon device and a buoy on the fourth pontoon device on the two flange blind plates one by one to reduce the weight of the flange blind plates, and the two flange blind plates will be recovered by a small boat at the subsequent high tide; Step 5: First, hang the multiple buoys on the four pontoon devices on the corresponding rope loops on the pipeline segment, and lower the corresponding pipe-hanging wire ropes through the two hoisting winches on the four pontoon devices to gradually lower the pipeline segment. The operator on the fourth pontoon device removes the manhole sealing plate, and the air in the pipeline segment overflows through the manhole, so that the pipeline segment can be lowered horizontally; Step 9, pipeline measurement, including measuring the following: Content 1: After the previous pipeline segment is installed, the precise coordinates of the pipe head are tested and the floating ball is tied. When installing the next pipeline segment, the position of the pipe head is estimated first, and the coordinates of the first pontoon device are measured by the total station on the shore, and compared with the coordinates of the pipe head position of the previous pipeline segment that has been installed, and the installation position of the first pontoon device is adjusted; Content 2: Set up a level in the axial direction of the sea pipe on the shore to observe the pipe-hanging wire ropes on the same side of the four buoyancy devices, and ensure that the pipe-hanging wire ropes on the same side of the four buoyancy devices are located on the same vertical plane by fine-tuning the anchor ropes of the four buoyancy devices; Content 3: Measure the placement depth of the pipeline segment through the water lump and adjust the lowering length of the pipe hanging wire rope; Step 10. After the pipeline segment is lowered to near the bottom of the base trench, under the command of the diver, the convex flange at the head of the pipeline segment is inserted into the concave flange at the tail of the previously installed pipeline segment, and the diver tightens the flange bolts between the flange ring and the concave flange.

2. The installation method of the shallow section sea discharge pipe according to claim 1 is characterized in that: The lifting bracket also includes two pairs of diagonal braces; each pair of diagonal braces is connected one by one between the top front side of the steel column and the front end top surface of the corresponding steel pontoon, and between the top rear side of the steel column and the rear end top surface of the corresponding steel pontoon.

3. The installation method of the shallow section sea discharge pipe according to claim 1 is characterized in that: One end of the pedal is installed on the inner side of the rear top surface of one buoyancy box through a pin shaft, and the other end of the pedal is installed on the inner side of the rear top surface of another buoyancy box through a positioning pin.

4. The installation method of the shallow section sea discharge pipe according to claim 1 is characterized in that: The construction process also includes: Step 11, post-installation inspection: Check the tightening of the flange bolts through the underwater camera, take photos of the tightness of the joints inside the pipe through the manhole, and after confirming that it meets the design requirements, unhook the pipe hanging wire rope; Step 12, post-installation processing: After each pipeline segment is installed, a hammer or a vertical pole is lowered on the first buoy device, and a diver places it on the pipe head of the pipeline segment. The coordinates of the pipe head are tested by the total station on shore, and a diver hangs a buoy on the pipe head.

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