Overall floating transportation construction method for locking steel pipe pile cofferdam and drilling platform

Abstract

The invention discloses an integral floating construction method for a fore shaft steel pipe pile cofferdam and a drilling platform, which is suitable for the construction of a bridge pile foundation deeply buried in bare rock, and comprises the following steps of: 1, processing the fore shaft steel pipe pile cofferdam capable of floating and the drilling platform which has buoyancy and takes a steel casing as a support on a dock; secondly, water is injected into the dock to float the machined fore shaft steel pipe pile cofferdam and the drilling platform which can be transported in a floating mode, and the floating fore shaft steel pipe pile cofferdam and the drilling platform are dragged to a construction site; thirdly, the floating fore shaft steel pipe pile cofferdam and the drilling platform are positioned and sunk to the leveled bare rock; fourthly, the posture of the fore shaft steel pipe pile cofferdam is adjusted, bottom sealing concrete is poured, and pile foundation construction is conducted after the bottom sealing concrete is poured; and fifthly, after pile foundation construction is completed, cofferdam structure water pumping is carried out, after water pumping, bearing platform and other main body structure construction is carried out, and after the main body structure goes out of water, water returning is carried out layer by layer in the cofferdam, and supports are dismantled.

Description

Technical Field

[0001] The invention relates to a locking steel pipe pile cofferdam and a drilling platform integral floating construction method, which is suitable for bare rock deep-buried underwater foundation construction. Background Art

[0002] The underwater pile foundation and cap in bridge engineering are key structural components, and their construction technology and selection are crucial to the success of the project.

[0003] For bare rock deep buried underwater foundation construction, the foundation pit of the cap is usually excavated first, and the excavation method is generally blasting. After the foundation pit is excavated, pile foundation and cap construction are carried out.

[0004] Pile foundation construction usually involves the construction of steel trestles and construction platforms. Since the geology is all bare rock, the "barge + rotary drill" is required to drill holes for steel pipe piles, and the "fishing method" is used to construct the upper structure of the trestles and construction platforms.

[0005] The steel casing of the pile foundation is installed on the drilling platform using large crawlers, and the pile foundation construction uses rotary drilling. After the pile foundation construction is completed, the drilling platform is removed and the foundation is constructed.

[0006] Due to the large head difference, double-wall steel cofferdam structure is usually used for the foundation protection construction, and the cofferdam installation process is selected according to the conditions of the construction site and the hydrological conditions. After the cofferdam is installed and sunk, the bottom concrete is poured. After the concrete strength reaches the design requirements, water is pumped out for foundation construction.

[0007] The problem is that for underwater pile foundation construction platforms, the fishing method is usually used. For deep-buried bare rock caps in water, the construction process of blasting first and then cofferdam is generally adopted. For such caps, the water level difference is large, and a double-wall steel cofferdam structure is usually used.

[0008] When constructing underwater platforms using the fishing method, in actual project implementation, the construction period is often tight and cannot meet the construction needs, and a separate working surface needs to be added for construction (barge + floating crane). When using a drilling platform to construct pile foundations, the positioning and installation of steel casings is difficult due to their large diameter and length. In addition, the steel casing is only used as a construction measure for pile foundations, resulting in a large waste of materials.

[0009] Although the double-walled steel cofferdam structure has great rigidity and reliable water-stopping performance, it still has some inevitable disadvantages, such as high costs of materials, processing, transportation and installation, high dependence on construction equipment, difficulty in controlling construction precision, and poor recycling and reuse effects. Summary of the invention

[0010] In view of the above problems, the purpose of the present invention is to provide a locking steel pipe pile cofferdam and drilling platform overall floating construction method, which is used in the construction of underwater bridge pile foundations and pedestals and has the advantages of fast construction speed, low construction cost, high construction efficiency, low construction risk and strong promotion and applicability.

[0011] A method for the overall floating construction of a locking steel pipe pile cofferdam and a drilling platform is suitable for the construction of bare rock deep-buried bridge pile foundations in water. The bare rock of the underwater bridge pile foundation is leveled. The construction method comprises the following steps: Step 1: Processing a floating lock-mouth steel pipe pile cofferdam and a buoyant drilling platform supported by a steel casing in the dock; Step 2: Fill the dock with water to float the processed floating interlocking steel pipe pile cofferdam and drilling platform, and drag the floating interlocking steel pipe pile cofferdam and drilling platform to the bridge pile foundation construction site; Step 3: Position and sink the floating lock-joint steel pipe pile cofferdam and drilling platform to the leveled bare rock; Step 4: Adjust the posture of the lock-mouth steel pipe pile cofferdam and pour the bottom concrete. After the bottom concrete pouring is completed, pile foundation construction is carried out; Step 5: After the pile foundation construction is completed, the cofferdam structure is pumped out, and after pumping out the water, the foundation and other main structures are constructed. After the main structure is out of water, the water is returned layer by layer in the cofferdam to remove the support.

[0012] The solution is further as follows: the drilling platform includes a plurality of vertically arranged steel casings, and the plurality of vertical steel casings are distributed and arranged according to the design requirements of the bridge pile foundation. A steel casing buoy is formed by arranging a plug at the bottom end of the steel casing. The plurality of vertical steel casings are connected and fixed to each other by an intermediate truss up and down to form a steel casing floating row. A crossbeam is connected to the upper end of the steel casing floating row, and a platform plate is laid on the crossbeam. The locking steel pipe pile cofferdam is arranged around the steel casing floating row. The locking steel pipe pile cofferdam includes an enclosure arranged around the steel casing floating row, and steel pipe piles are arranged on the outside of the enclosure and connected to the enclosure and arranged. The steel pipe piles are tightly connected to each other by locking buckles to form a steel pipe pile cofferdam. The bottom of the steel pipe piles is sealed to form a steel pipe pile buoy, and the steel pipe pile cofferdam is connected to the steel casing floating row to form an integrated floating structure.

[0013] A further solution is that the enclosure is a rectangular enclosure, an oblique rod support is provided between two adjacent sides of the rectangular enclosure, a straight rod support is provided between a pair of opposite sides of the rectangular enclosure, and the steel casing floating row is connected to the rectangular enclosure by a connecting rod to form an integrated floating structure.

[0014] A further solution is that the inner bottom end of the steel casing is sealed by pouring concrete to form a steel casing buoy, and the bottom of the steel pipe pile is sealed by welding steel plates to form a steel pipe pile buoy.

[0015] The solution is further that: the method further comprises: after the water head difference inside and outside the cofferdam is balanced, using a crawler crane + vibratory hammer to pull out the steel pipe piles.

[0016] The plan further includes: the third step: positioning and sinking the floating locked steel pipe pile cofferdam to the leveled bare rock is achieved by injecting water into the steel pipe piles and steel casing to allow the entire structure to sink. After sinking to the designed elevation, the bottom of the steel pipe piles is supported and sealed underwater. After the inspection is completed, the fourth step is executed: pouring the bottom concrete.

[0017] The beneficial effects of the present invention are: the method of the present invention is applied in the construction of underwater bridge pile foundations and caps, with fast construction speed, low construction cost, high construction efficiency, low construction risk and strong popularization and applicability, and its advantages include: 1. Set a sealing plate at the bottom of the steel pipe pile By setting a sealing plate at the bottom of the steel pipe piles of the locking steel pipe pile cofferdam, the steel pipe pile cofferdam can be "floated" and the locking steel pipe pile cofferdam can be processed in a processing plant and floated to the bridge site as a whole, replacing the conventional on-site inserting and hammering one by one, thus changing the conventional installation method of the locking steel pipe pile cofferdam.

[0018] 2. The lock steel pipe cofferdam is processed as a whole in the factory and then floated By positioning the steel pipe piles in the factory through enclosures, they are not affected by other loads during installation, ensuring the installation accuracy of the steel pipe piles. The overall floating method is used to change the conventional pumping and supporting process, so that the enclosure and supporting structure form a system before pumping, reducing the stress on the steel pipe piles.

[0019] 3. Set a concrete cover plate at the bottom of the steel casing A concrete cover plate is set at the bottom of the steel casing, which can be removed by a drilling rig during the pile foundation construction process, and is more operable than a steel cover plate. The cover plate allows the steel casing to generate buoyancy itself, providing buoyancy for the upper platform structure.

[0020] 4. Overall design of steel casing and drilling platform The overall design of the steel casing and the drilling platform reduces the steel consumption of conventional drilling platforms by using the steel casing as a supporting structure. The processing, transportation, and positioning of the steel casing and the drilling platform can be carried out simultaneously with the construction of the steel trestle, thus reducing the construction period.

[0021] 5. Floating of steel casing and interlocking steel pipe piles as a whole By integrating the locking steel pipe piles, steel casing and steel platform in the factory and floating them into place at one time, and utilizing the precise positioning of the locking steel pipe piles, the accuracy and verticality of the steel casing are ensured, solving the problem of difficult control of installation accuracy for each pile.

[0022] The present invention is described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic plan view of the upper end of the locking steel pipe pile cofferdam of the present invention without the platform cross beam; Figure 2 It is a schematic diagram of the upper end plane of the locking steel pipe pile cofferdam with a platform cross beam of the present invention; Figure 3 It is a schematic cross-sectional view of one side of the locking steel pipe pile cofferdam with a platform plate of the present invention; Figure 4 It is a schematic cross-sectional view of the other side of the locking steel pipe pile cofferdam with a platform plate according to the present invention. DETAILED DESCRIPTION

[0024] A method for the overall floating construction of a locking steel pipe pile cofferdam and a drilling platform is suitable for the construction of bare rock deep-buried bridge pile foundations in water. The bare rock of the underwater bridge pile foundation is leveled. The construction method comprises the following steps: Step 1: Processing a floating lock-mouth steel pipe pile cofferdam and a buoyant drilling platform supported by a steel casing in the dock; Step 2: Fill the dock with water to float the processed floating interlocking steel pipe pile cofferdam and drilling platform, and drag the floating interlocking steel pipe pile cofferdam and drilling platform to the bridge pile foundation construction site; Step 3: Position and sink the floating lock-joint steel pipe pile cofferdam and drilling platform to the leveled bare rock; Step 4: Adjust the posture of the lock-mouth steel pipe pile cofferdam and pour the bottom concrete. After the bottom concrete pouring is completed, pile foundation construction is carried out; Step 5: After the pile foundation construction is completed, the cofferdam structure is pumped out, and after pumping out the water, the foundation and other main structures are constructed. After the main structure is out of water, the water is returned layer by layer in the cofferdam to remove the support.

[0025] like Figures 1 to 4 As shown: the drilling platform includes a plurality of vertically arranged steel casings 1, and the plurality of vertical steel casings 1 are distributed and arranged according to the design requirements of the bridge pile foundation. A steel casing buoy is formed by arranging a plug 101 at the bottom end of the steel casing 1. The plurality of vertical steel casings are connected and fixed to each other by an intermediate truss 2 up and down to form a steel casing floating row. The intermediate truss 2 is sealed up and down in a rice-shaped manner. A supporting main crossbeam 5 is connected to the upper end of the steel casing floating row, and a platform plate 7 is laid on the supporting main crossbeam 5. The locking steel pipe pile cofferdam is arranged around the steel casing floating row. The locking steel pipe pile cofferdam includes an enclosure 3 arranged around the steel casing floating row, and steel pipe piles 4 are arranged and connected to the enclosure 3 on the outside of the enclosure 3. The steel pipe piles 4 are connected to each other by a locking buckle to form a locking steel pipe pile cofferdam. The bottom of the steel pipe pile 4 is sealed 401 to form a steel pipe pile buoy. The locking steel pipe pile cofferdam is connected to the steel casing floating row to form an integrated floating structure.

[0026] The enclosure 3 is a rectangular enclosure. In order to enhance the firmness of the enclosure 3: a plurality of inclined rod supports 301 are arranged between two adjacent sides of the rectangular enclosure, and a plurality of straight rod supports 302 are arranged between a pair of opposite sides. The steel casing floating row is connected to the rectangular enclosure by a connecting rod 6 to form an integrated floating structure.

[0027] Wherein: the inner bottom end of the steel casing is sealed by pouring concrete to form a steel casing buoy, and the bottom of the steel pipe pile is sealed by welding steel plates to form a steel pipe pile buoy.

[0028] The method further comprises: after the water head difference inside and outside the cofferdam is balanced, using a crawler crane + a vibrating hammer to pull out the steel pipe piles.

[0029] In the third step, the floating locking steel pipe pile cofferdam is positioned and sunk to the leveled bare rock by injecting water into the steel pipe piles and the steel casing to make the entire structure sink. After sinking to the designed elevation, the bottom of the steel pipe piles is supported and sealed underwater. After the inspection is completed, the fourth step is executed: pouring the bottom sealing concrete.

[0030] The following is a specific embodiment: The steel cofferdam adopts Φ820×14mm locking steel pipe piles, the outer dimensions of the cofferdam are 57.85m×32.93m (length×width), and the length of the steel pipe piles is 24m; the head difference between the inside and outside of the cofferdam is 16.6m, and two internal supports are set in the cofferdam 3. The bottom concrete of the steel casing 1 adopts C25 underwater concrete with a bottom thickness of 2m; the first purlin of the cofferdam 3 adopts 2HN700×300 steel, and the brace adopts φ800×16 steel support. The remaining internal supports are φ800×16 steel support and double-jointed and 2HN700×300 steel. The second purlin adopts 2HN700×300 steel, the brace of the straight rod support 302 adopts 2HN700×300 steel, and the internal supports of the remaining diagonal rod support 301 are φ800×16 steel support and 2HN700×300 steel. The size of the steel casing 1 is φ2500×16mm. The steel casing 1 also serves as the supporting steel pipe of the drilling platform. A 50cm concrete bottom plate is set at the bottom of the steel casing 1. The steel casing 1 is connected by a steel truss. The steel casing 1 is connected to the cofferdam of the locking steel pipe pile 4 by steel. The steel bracket is set on the top side of the steel casing 1. The main beam 5 is supported by the steel distribution beam as the drilling platform, and a steel platform 7 is set up on the main beam 5. The bottom of the steel pipe pile 4 is blocked with a 16mm steel plate. The locking steel pipe pile cofferdam, steel casing, and drilling platform are processed into a whole in the dock and floated to the bridge position after water is injected into the dock (steel casing and steel pipe piles can provide buoyancy). After being floated to the bridge site, water is injected into the steel pipe piles and steel casing to make the structure sink as a whole. After sinking to the designed elevation, the bottom of the steel pipe piles is supported and sealed underwater. After inspection, the bottom concrete is poured. After the bottom concrete is poured, the pile foundation is constructed. After the pile foundation construction is completed, the cofferdam structure is pumped out. After the pumping, the foundation and other main structures are constructed. After the main structure is out of water, the water is returned layer by layer in the cofferdam to remove the support. After the head difference inside and outside the cofferdam is balanced, the steel pipe piles are pulled out using a crawler crane + vibrating hammer.

[0031] The above-mentioned locking steel pipe pile cofferdam and drilling platform overall floating construction method embodiment, by setting a sealing plate at the bottom of the steel pipe pile of the locking steel pipe pile cofferdam, makes the steel pipe pile cofferdam "float", so that the locking steel pipe pile cofferdam can be processed in a processing plant and floated to the bridge position as a whole, replacing the conventional on-site one-by-one insertion, and changing the conventional locking steel pipe pile cofferdam installation method. By forming the locking steel pipe pile, steel casing, and steel platform into a whole in the factory, floating them in place at one time, and using the precise positioning of the locking steel pipe pile, the accuracy and verticality of the steel casing are guaranteed, and the difficulty of controlling the accuracy of each installation is solved.

Claims

1. A method for the overall floating construction of a locking steel pipe pile cofferdam and a drilling platform, which is suitable for the construction of bridge pile foundations buried deep in water with bare rock, and for leveling the bare rock of the underwater bridge pile foundation, characterized in that: The construction method comprises the following steps: Step 1: Processing a floating lock-end steel pipe pile cofferdam and a buoyant drilling platform supported by a steel casing in the dock; Step 2: Fill the dock with water to float the processed floating interlocking steel pipe pile cofferdam and drilling platform, and drag the floating interlocking steel pipe pile cofferdam and drilling platform to the bridge pile foundation construction site; Step 3: Position and sink the floating interlocking steel pipe pile cofferdam and drilling platform to the leveled bare rock; Step 4: Adjust the posture of the lock-mouth steel pipe pile cofferdam and pour the bottom concrete. After the bottom concrete pouring is completed, pile foundation construction is carried out; Step 5: After the pile foundation construction is completed, the cofferdam structure is pumped out, and after pumping out the water, the foundation and other main structures are constructed. After the main structure is out of water, the water is returned layer by layer in the cofferdam to remove the support.

2. The construction method according to claim 1, characterized in that: The drilling platform includes a plurality of vertically arranged steel casings, which are distributed and arranged according to the design requirements of the bridge pile foundation. A steel casing buoy is formed by arranging a plug at the bottom end of the steel casing. The plurality of vertical steel casings are connected and fixed to each other by trusses up and down to form a steel casing floating row. A crossbeam is connected to the upper end of the steel casing floating row, and a platform plate is laid on the crossbeam. The locking steel pipe pile cofferdam is arranged around the steel casing floating row. The locking steel pipe pile cofferdam includes an enclosure arranged around the steel casing floating row, and steel pipe piles are arranged on the outside of the enclosure and connected to the enclosure. The steel pipe piles are tightly connected to each other by locking buckles to form a steel pipe pile cofferdam. The bottom of the steel pipe piles is blocked to form a steel pipe pile buoy. The steel pipe pile cofferdam is connected to the steel casing floating row to form an integrated floating structure.

3. The construction method according to claim 2, characterized in that: The enclosure is a rectangular enclosure, with oblique rod supports arranged between two adjacent sides of the rectangular enclosure, and straight rod supports arranged between a pair of opposite sides of the rectangular enclosure. The steel casing floating row is connected to the rectangular enclosure by connecting rods to form an integrated floating structure.

4. The construction method according to claim 2, characterized in that: The inner bottom end of the steel casing is sealed by pouring concrete to form a steel casing buoy, and the bottom of the steel pipe pile is sealed by welding steel plates to form a steel pipe pile buoy.

5. The construction method according to claim 1, characterized in that: The method further comprises: after the water head difference inside and outside the cofferdam is balanced, using a crawler crane + a vibrating hammer to pull out the steel pipe piles.

6. The construction method according to claim 1, characterized in that: The third step: positioning and sinking the floating locked steel pipe pile cofferdam to the leveled bare rock is achieved by injecting water into the steel pipe piles and steel casing to make the entire structure sink. After sinking to the designed elevation, the bottom of the steel pipe piles is supported and sealed underwater. After the inspection is completed, the fourth step is executed: pouring the bottom sealing concrete.

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