A steel sheet pile cofferdam construction method

Abstract

The application provides a steel sheet pile cofferdam construction method, and relates to the technical field of cofferdam construction.The steel sheet pile cofferdam construction method comprises the following steps: S1, measuring and lofting; S2, setting the outermost inflatable oil-water separation fence; S3, assembling the floating ship and the pile machine; S4, pile hole positioning; S5, positioning the steel pipe pile machine and hoisting the pile; S6, inserting the steel pipe pile, hammering and sinking the pile, and checking the quality of the steel pipe pile; S7, moving the pile machine to drive the next pile; S8, welding the steel enclosing purlin between the steel pipe piles; S9, driving the sinking pile through the steel sheet pile machine; and S10, setting the outer inflatable oil-water separation fence of the steel sheet pile.In the application, the outer inflatable oil-water separation fence of the steel sheet pile can effectively block the oil and water leakage, thereby ensuring environmental protection and avoiding oil and water pollution of the water surface; meanwhile, the diver can work underwater, and underwater photography can be used to check the quality, so that the construction quality can be further ensured, the safety of the cofferdam is ensured, and the practicality is high.

Description

Technical Field

[0001] This invention relates to the field of cofferdam construction technology, and in particular to a method for constructing a steel sheet pile cofferdam. Background Technology

[0002] Due to navigation requirements in river basins, underwater cofferdams are often designed as buried structures, making significant contributions to flood control and navigation. However, given the wide and sparse development of bedrock fissures, uneven overburden thickness, and the fact that many rivers in my country are located within national nature reserves, steel cofferdams are generally used for cofferdam construction. However, current steel sheet pile cofferdam construction methods may result in oil and water leakage during construction, causing pollution to the water surface and hindering environmental protection, thus requiring improvement. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by proposing a steel sheet pile cofferdam construction method.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a method for constructing a steel sheet pile cofferdam, the method comprising the following steps:

[0005] S1, Measurement and layout;

[0006] S2, set the outermost pneumatic oil-water separator;

[0007] S3, the assembled floating hull and pile driver arrive on site;

[0008] S4, pile hole positioning;

[0009] S5, the steel pipe pile driver is in place and the pile is hoisted;

[0010] S6, steel pipe pile driving and hammering, and acceptance of the quality of steel pipe piles;

[0011] S7, the pile driver is moved to drive the next pile;

[0012] S8, steel walers between welded steel pipe piles;

[0013] S9 uses a sheet pile driver to drive piles;

[0014] S10, Install an air-inflatable oil-water separator on the outside of the steel sheet pile;

[0015] S11, the inner and outer sides of the steel sheet pile are sealed with geotextile, and then divers work underwater and take underwater photos to check the quality.

[0016] S12, and then use an electric boat to conduct topographical surveys of the cofferdam foundation;

[0017] S13, Clearing and leveling the foundation of the cofferdam;

[0018] S14, compact the foundation riprap of the cofferdam;

[0019] S15, divers work together underwater to stack the materials neatly, with alternating layers, and manually tamp them down;

[0020] S16, dig a ditch at the toe of the cofferdam slope;

[0021] S17, leveling the water-facing side of the cofferdam with gravel;

[0022] S18, Waterproof canvas is laid on the water-facing side of the cofferdam;

[0023] S19, composite geotextile laying on the water-facing side of the cofferdam;

[0024] S20, leveling the water-facing side of the cofferdam with sandbags and gravel;

[0025] S21, the cofferdam's water-facing side is paved with riprap;

[0026] S22, after a 14-day settlement period, the cofferdam began to be pumped out and drained;

[0027] S23, verify the slope surface and top elevation, rectify to meet design requirements, and finally conduct acceptance.

[0028] To ensure the construction proceeds, the present invention is improved in that, in S1, the measurement and setting out specifically includes:

[0029] I. Establishment of the construction baseline: Three measurement control points were set up along the reservoir, with a distance of about 100m between them, and the points were frequently checked to ensure the accuracy of the control.

[0030] 2. Establishment of elevation control points: Using the elevation control points provided by Party A, the elevations will be transferred to the bank of the construction area, control point fixed stakes will be driven, and the elevations of the stakes will be checked and calculated to meet the technical specifications. Then, Party A's approval will be obtained, and the points will be used as construction elevation control points. In addition, a water level observation gauge will be driven at the water's edge, with the gauge scale divided to the centimeter, and the elevation of the top of the gauge will be measured to observe the daily water level.

[0031] To improve this invention, in S2, the outermost aerated oil-water separator specifically includes:

[0032] 1. Purchase qualified environmentally friendly oil booms in accordance with relevant requirements for water pollution prevention and environmental protection;

[0033] 2. Transport the environmentally friendly oil booms to the construction area;

[0034] III. Arrange crew members and operators to deploy oil booms and secure national standards on the water;

[0035] IV. On-site inspection and verification on the water shall be completed until the requirements are met.

[0036] To improve practicality, the present invention is improved such that, in step S9, the pile driving specifically includes:

[0037] 1. Arrange for a mobile crane to lift the steel pipe piles (sheet piles) from the shore onto the pile barge and transport them by water to the construction area;

[0038] 2. Construction of steel pipe piles for the water-based embankment: A 25T crane vessel is used in conjunction with a ZD-90 vibratory hammer to drive the steel pipe piles. After the steel pipe piles are driven, the crane vessel is used to weld the walers between the pipe piles.

[0039] To reduce potential hazards, the present invention has an improvement in S5. During the assembly of the piling machine equipment, all fasteners should be inspected. Counterweights should not be installed before the fasteners are tightened. After assembly, the whole machine should be test-run to confirm that all transmission mechanisms, gearboxes, protective covers, etc. are in good condition and that all components are securely connected.

[0040] To ensure safety, the present invention is improved in that, in S5, the steel sheet pile stacking site should be flat and firm, the combined steel sheet pile stacking height should not exceed 3 layers, there should be no high voltage lines in the sheet pile construction operation area, the operation area should have obvious signs or fences, and the monitoring distance of the pile hammer during the driving process should not be less than 5m.

[0041] To avoid throwing deviation, the present invention is improved in S15 by using a waterborne engineering vessel for positioning when the water depth is below 3.5 meters. A bottom-opening mud barge transports sandbags from the shore to the positioning vessel for quantitative grid throwing. The water depth is measured by tracking the throwing position and comparing the theoretical water depth with the actual water depth to avoid throwing deviation. At the same time, the divers are uniformly directed by a designated person to ensure that the divers do not carry out underwater throwing operations during underwater operations.

[0042] To ensure quality, the present invention is improved in S15 by calculating the filling volume of the cofferdam in 1-meter thick sections from the deepest part of the riverbed, and then dumping the filling in layers. During dumping, the assembly vessel is used to anchor the front and rear sections with figure-eight anchors according to the measurements for accurate positioning. The bottom-opening barge is used for dumping. The riverbed water depth is continuously measured and the dumping volume is controlled. After every 1-meter thickness is dumped, the surveyor on the water positioning vessel uses the measurement data to require the diver to use the underwater leveling track to conduct an underwater inspection and leveling of the dumped cofferdam body. After the flatness is found to be without deviation, construction continues.

[0043] To improve practicality, the present invention is improved in that, in S18, firstly, 30cm of gravel is used to level the water-facing surface, and then waterproof canvas is used to cover, fix, press the edges, level, and compact.

[0044] To avoid slope collapse, the present invention includes the following improvements: In S22, the cofferdam is pumped out using a mixed-flow pump. The pumping rate inside the cofferdam must be strictly controlled, with the water level drop rate limited to 0.5–0.7 m / day to prevent the cofferdam and its side slopes from collapsing due to excessive drainage. During the pumping process, the settlement and displacement of the cofferdam are monitored. At the same time, the pumping capacity is adjusted in a timely manner based on the seepage and stability of the cofferdam and its side slopes. If problems are found, measures such as slowing down the pumping rate are taken promptly.

[0045] Compared to existing technologies, this invention effectively prevents oil and water leakage by setting up an inflatable oil-water separation barrier on the outside of the steel sheet pile, thereby ensuring environmental protection and preventing oil and water pollution of the water surface. At the same time, underwater operations by divers and underwater photography to check the quality can further ensure the construction quality and ensure the safety of the cofferdam, making it highly practical.

[0046] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0047] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This invention provides a flowchart of the construction process for a steel sheet pile isolation combined fence, which is part of a steel sheet pile cofferdam construction method.

[0050] Figure 2 This invention provides a flowchart of the cofferdam construction process for a steel sheet pile cofferdam construction method. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] Example 1, see Figure 1-2 The construction method for this sheet pile cofferdam includes the following steps:

[0053] S1, Measurement and layout;

[0054] S2, set the outermost pneumatic oil-water separator;

[0055] S3, the assembled floating hull and pile driver arrive on site;

[0056] S4, pile hole positioning;

[0057] S5, the steel pipe pile driver is in place and the pile is hoisted;

[0058] S6, steel pipe pile driving and hammering, and acceptance of the quality of steel pipe piles;

[0059] S7, the pile driver is moved to drive the next pile;

[0060] S8, steel walers between welded steel pipe piles;

[0061] S9 uses a sheet pile driver to drive piles;

[0062] S10, Install an air-inflatable oil-water separator on the outside of the steel sheet pile;

[0063] S11, the inner and outer sides of the steel sheet pile are sealed with geotextile, and then divers work underwater and take underwater photos to check the quality.

[0064] S12, and then use an electric boat to conduct topographical surveys of the cofferdam foundation;

[0065] S13, Clearing and leveling the foundation of the cofferdam;

[0066] S14, compact the foundation riprap of the cofferdam;

[0067] S15, divers work together underwater to stack the materials neatly, with alternating layers, and manually tamp them down;

[0068] S16, dig a ditch at the toe of the cofferdam slope;

[0069] S17, leveling the water-facing side of the cofferdam with gravel;

[0070] S18, Waterproof canvas is laid on the water-facing side of the cofferdam;

[0071] S19, composite geotextile laying on the water-facing side of the cofferdam;

[0072] S20, leveling the water-facing side of the cofferdam with sandbags and gravel;

[0073] S21, the cofferdam's water-facing side is paved with riprap;

[0074] S22, after a 14-day settlement period, the cofferdam began to be pumped out and drained;

[0075] S23, verify the slope surface and top elevation, rectify to meet design requirements, and finally conduct acceptance.

[0076] Specifically, in S1, the measurement and setting out includes:

[0077] I. Establishment of the construction baseline: Three measurement control points were set up along the reservoir, with a distance of about 100m between them, and the points were frequently checked to ensure the accuracy of the control.

[0078] 2. Establishment of elevation control points: Using the elevation control points provided by Party A, the elevations will be transferred to the bank of the construction area, control point fixed stakes will be driven, and the elevations of the stakes will be checked and calculated to meet the technical specifications. Then, Party A's approval will be obtained, and the points will be used as construction elevation control points. In addition, a water level observation gauge will be driven at the water's edge, with the gauge scale divided to the centimeter, and the elevation of the top of the gauge will be measured to observe the daily water level.

[0079] Specifically, in S2, setting the outermost aerated oil-water separator includes:

[0080] 1. Purchase qualified environmentally friendly oil booms in accordance with relevant requirements for water pollution prevention and environmental protection;

[0081] 2. Transport the environmentally friendly oil booms to the construction area;

[0082] III. Arrange crew members and operators to deploy oil booms and secure national standards on the water;

[0083] IV. On-site inspection and verification on the water shall be completed until the requirements are met.

[0084] Specifically, in step S9, the pile driving process includes:

[0085] 1. Arrange for a mobile crane to lift the steel pipe piles (sheet piles) from the shore onto the pile barge and transport them by water to the construction area;

[0086] 2. Construction of steel pipe piles for the water-based embankment: A 25T crane vessel is used in conjunction with a ZD-90 vibratory hammer to drive the steel pipe piles. After the steel pipe piles are driven, the crane vessel is used to weld the walers between the pipe piles.

[0087] Specifically, in S5, when assembling the piling machine equipment, all fasteners should be inspected. Counterweights should not be installed before the fasteners are tightened. After assembly, the whole machine should be test-run to confirm that all transmission mechanisms, gearboxes, protective covers, etc. are in good condition and that all components are securely connected.

[0088] Specifically, in S5, the steel sheet pile stacking site should be flat and firm, the combined steel sheet pile stacking height should not exceed 3 layers, there should be no high voltage lines in the sheet pile construction operation area, the operation area should have obvious signs or fences, and the monitoring distance of the pile hammer during the driving process should not be less than 5m.

[0089] Specifically, in S15, when the water depth is below 3.5 meters, a waterborne engineering vessel is used for positioning. A bottom-opening mud barge loads sandbags from the shore to the positioning vessel for quantitative grid throwing. The water depth is measured by tracking the throwing position and comparing the theoretical water depth with the actual water depth to avoid throwing deviation. At the same time, the divers are under the unified command of a designated person to ensure that the divers do not carry out underwater throwing operations during underwater operations.

[0090] Specifically, in S15, the process includes calculating the filling volume of the cofferdam by dividing it into 1-meter thick sections from the deepest part of the riverbed and placing it in layers. During placement, the assembly vessel is used to anchor the front and rear sections with figure-eight anchors for accurate positioning based on measurements. The bottom-opening barge is used for placement. The riverbed water depth is continuously measured and the placement volume is controlled. After every 1-meter thickness is placed, the surveyor on the water positioning vessel uses underwater leveling rails to inspect and level the underwater cofferdam body according to the measurement data. Once the flatness is found to be within tolerance, construction continues.

[0091] Specifically, in S18, the surface facing the water is first leveled with 30cm of gravel, and then covered, fixed, edged, leveled and compacted with waterproof canvas.

[0092] Specifically, in S22, the cofferdam is pumped out using mixed-flow pumps. The rate of water drop during pumping within the cofferdam must be strictly controlled, with the water level drop limited to 0.5–0.7 m / day to prevent the cofferdam and its side slopes from collapsing due to excessive drainage. Settlement and displacement of the cofferdam are monitored during the pumping process. The pumping capacity is adjusted in a timely manner based on the seepage and stability of the cofferdam and its side slopes. If any problems are found, measures such as slowing down the pumping speed are taken promptly.

[0093] As can be seen from the above embodiments, the present invention can effectively prevent oil and water leakage by setting an inflatable oil-water separation barrier on the outside of the steel sheet pile, thereby ensuring environmental protection and avoiding oil and water pollution of the water surface. At the same time, underwater operations by divers and underwater photography to check the quality can further ensure the construction quality and ensure the safety of the cofferdam, making it highly practical.

[0094] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method of constructing a steel sheet pile cofferdam, characterized by, The steel sheet pile cofferdam construction method comprises the following steps: S1, measuring and setting out; S2, setting the outermost inflatable oil-water separation fence; S3, assembling the floating ship and pile driver to approach; S4, pile hole positioning; S5, positioning the steel pipe pile driver and hoisting the pile; S6, inserting the steel pipe pile into the pile hammer and sinking the pile, and checking the quality of the steel pipe pile; S7, moving the pile driver to drive the next pile; S8, welding the steel enclose purlin between the steel pipe piles; S9, driving the sinking pile by the steel sheet pile driver; S10, setting the inflatable oil-water separation fence outside the steel sheet pile; S11, closing the geotextile inside and outside the steel sheet pile, and then the diver works underwater, and the quality is checked by underwater photography; S12, then the cofferdam foundation topography is measured by the electric boat; S13, the cofferdam foundation is cleared and leveled; S14, the cofferdam foundation blocks are compacted; S15, the diver works underwater, and the blocks are stacked neatly, staggered in layers, and manually compacted; S16, the cofferdam toe ditch is dug; S17, the cofferdam water-facing surface is leveled with gravel; S18, the cofferdam water-facing surface is laid with waterproof canvas; S19, the cofferdam water-facing surface is laid with composite geotextile; S20, the cofferdam water-facing surface is leveled with sand bags and gravel; S21, the cofferdam water-facing surface is paved with block stone; S22, after the cofferdam has settled for 14 days, water is pumped out and drained; S23, the slope and slope top elevation are reviewed, corrected to meet the design requirements, and finally accepted.

2. The steel sheet pile cofferdam construction method according to claim 1, characterized by: In S1, the measuring and setting out specifically comprises: One, establishment of construction baseline, three measurement control points are set at the reservoir side with a distance interval of 100 m, and are frequently checked to ensure the accuracy of control; Two, establishment of elevation control point, the elevation control point provided by Party A is transferred to the shore of the construction area, a control point fixed pile is punched, and the elevation of the pile is checked and calculated to be within the technical specification, and then is reported to Party A for approval as the construction elevation control point, in addition, a water level observation scale is punched at the water side, the scale is divided and marked to centimeter, the top elevation of the scale is measured, and is used for observing the daily water level.

3. The method according to claim 1, wherein: In S2, setting the outermost inflatable oil-water separation fence specifically comprises: One, purchasing qualified environmental protection oil containment boom according to the requirements of water pollution prevention and environmental protection; Two, transporting the environmental protection oil containment boom to the construction water area; Three, arranging the crew and operators to lay the oil containment boom on water and bind the national standard; Four, on-site water report, and perfecting to be qualified.

4. The steel sheet pile cofferdam construction method according to claim 1, characterized by: In S9, driving the sinking pile specifically comprises: One, arranging the automobile crane to hoist the steel pipe pile or steel sheet pile on the shore to the pile barge, and transporting it to the construction water area; Two, carrying out the steel pipe pile or steel sheet pile construction on water, using the assembled 25T crane ship to cooperate with the ZD-90 type vibration hammer to drive the steel pipe pile or steel sheet pile, and after the steel pipe pile or steel sheet pile driving is completed, the crane ship cooperates with the pipe pile to weld the enclose purlin between the pipes.

5. The steel sheet pile cofferdam construction method according to claim 1, characterized by: In S5, when the pile driver equipment is assembled, the fasteners should be checked, the counterweight should not be installed before the fasteners are tightened, and after the assembly is completed, the whole machine should be tested to run to confirm that the transmission mechanism, gear box and protective cover are good, and the parts are firmly connected.

6. The steel sheet pile cofferdam construction method according to claim 1, characterized by: In S5, the steel sheet pile stacking site should be flat and solid, the combined steel sheet pile stacking height should not exceed 3 layers, there should be no high-voltage lines in the steel sheet pile construction operation area, the operation area should have obvious signs or fences, and the pile hammer should be monitored at a distance of not less than 5m during construction.

7. The method according to claim 1, wherein: In S15, when the water depth is below 3.5 meters, an overwater engineering ship is used for positioning, a bottom-opening barge is used to load sand bags from the shore side to the positioning ship for grid quantification and throwing, the water depth is measured and compared with the theoretical water depth and the actual water depth to avoid deviation, and a diver is uniformly commanded to ensure that the diver does not perform underwater throwing operations while working underwater.

8. The method according to claim 1, wherein: In S15, specifically, the cofferdam is divided into layers and sections according to 1m thickness, the filling amount is calculated, and the cofferdam is thrown in layers. During throwing, the assembled ship is used to position the eight-character anchor according to the measurement, the bottom-opening barge is used for throwing, the riverbed water depth is measured and the throwing amount is controlled, and the diver uses the underwater leveling track to check and level the underwater cofferdam body according to the measurement data, and the construction continues after the deviation is eliminated.

9. The method according to claim 1, wherein: In S18, first, the riverbed is leveled with 30cm gravel, then waterproof canvas is used for covering, fixing, edge pressing, leveling and compaction.

10. The method of claim 1, wherein: In S22, the cofferdam water is pumped out by a mixed flow pump, and the water level in the cofferdam must be strictly controlled to prevent the cofferdam and the two side slopes from collapsing due to excessive drainage speed. The water level drop speed is limited to 0.5-0.7m per day and night. During the pumping process, the settlement displacement of the cofferdam is monitored, and the pumping capacity is adjusted in time according to the seepage and stability of the cofferdam and the two side slopes. If problems are found, measures should be taken to slow down the pumping speed.

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