Construction method for deep water sinking and anchoring of super-long and large-diameter steel casing

Abstract

The application discloses a kind of ultra-long large-diameter steel casing deep water sinking anchoring construction methods, comprising: erecting drilling platform, presetting anchoring position, temporarily fixed to the drilling platform by closed steel casing;Cut off the steel casing top steel plate, remove the steel casing top closure, place water pump, and lengthen steel casing to design length, weld the multiple jacks under the I-beam to support under corbel to share the gravity of steel casing;Remove temporary fixation, control the water volume in steel casing by water pump to make steel casing maintain vertical floating state, continue to water injection to gradually reduce jack support force until unloading and steel casing vertical balance;When sinking to specified position, use water pump to pump water, make steel casing maintain vertical floating state, cut off the steel casing bottom plate, and pour concrete from the casing top to anchoring position, jack gradually unloads and withdraws, and steel casing naturally sinks to anchoring position and anchors;The application makes the overall sinking of steel casing convenient and fast, safe, environmentally friendly, high-quality and efficient, saves construction period and saves cost.

Description

Technical Field

[0001] This invention relates to the field of highway bridge construction technology, and in particular to a method for deep-water immersion and anchoring of ultra-long diameter steel casings. Background Technology

[0002] Long, long-diameter permanent steel casings are increasingly used in pile foundations for ultra-deep waters, both offshore and inland. For example, a permanent steel casing with a diameter of 3.6m, a length of 48m, and a weight of over 100 tons presents a significant challenge for transportation and installation. The traditional method involves sectional transportation and installation. This involves constructing access roads beforehand, transporting the steel casing in sections to the site for processing and assembly, and then using large floating cranes to lift and weld the casings into place. This sectional transportation and installation method typically has the following drawbacks:

[0003] 1. The construction of access roads is time-consuming, occupies a large area, and has high costs and transportation expenses;

[0004] 2. On-site processing and installation take a long time, resulting in low construction efficiency and poor economic benefits;

[0005] 3. Repeated hoisting and welding processes compromise processing precision and significantly reduce construction quality;

[0006] 4. Large lifting equipment has high site requirements, and there are situations where it is impossible to enter or operate. During operation, there are high safety risks and significant environmental pollution.

[0007] 5. Large floating platforms are not suitable for reservoirs with drastic water level changes. Large water level changes make it difficult to adjust the anchor cables of the floating platform, and the stability of the floating platform cannot be guaranteed, which can easily lead to the overturning of the ultra-long and ultra-heavy steel casing. Summary of the Invention

[0008] To address the problems existing in the prior art, the purpose of this invention is to provide a method for deep-water immersion and anchoring of ultra-long diameter steel casings. This invention makes the overall sinking of the steel casing convenient, quick, safe, environmentally friendly, high-quality, and efficient, saving construction time and costs.

[0009] To achieve the above objectives, the technical solution adopted by this invention is: a method for deep-water immersion and anchoring construction of ultra-long diameter steel casings, comprising the following steps:

[0010] Step 1: Set up a drilling platform. At the position where the steel casing is placed on the top of the riverbed, pre-set an anchoring position that extends into the moderately weathered rock layer. Use welded I-beams to temporarily fix the sealed steel casing to the drilling platform.

[0011] Step 2: Cut off the top steel plate of the steel casing, remove the top seal of the steel casing, place the water pump, and extend the steel casing to the designed length. Weld multiple jacks under the I-beam to share the weight of the steel casing.

[0012] Step 3: Control the water volume inside the steel casing with a water pump to make the steel casing float or sink while maintaining vertical balance. At this time, release the temporary fixation. The steel casing can maintain balance by controlling the water volume inside the steel casing and be lowered using jacks.

[0013] Step 4: After the steel casing sinks to the designated position and is at a certain height from the riverbed, cut off the bottom plate of the steel casing. The weight of the steel casing is borne by the jacks. Pour concrete from the top of the casing to the anchoring position, lower the steel casing with the jacks, and the steel casing will naturally sink to the anchoring position and be anchored.

[0014] As a further improvement of the present invention, in step 1, the depth of the anchoring position is 0.5m-1.5m.

[0015] As a further improvement of the present invention, the steel casing is temporarily fixed at a position where the top opening of the steel casing is 1m-1.5m above the drilling platform by four I25 I-beams. Four 50t-class jacks are placed under the I-beams to provide adjustable support for the steel casing.

[0016] As a further improvement of the present invention, considering that the weight of the steel casing, water level, and water flow velocity will all change after the steel casing is extended, the following measures are formulated to maintain the stability of the steel casing based on the assumed range of water level changes before the fixing is removed, taking into account different historical water level conditions:

[0017]

[0018] H—Depth of the steel casing submerged in water;

[0019] h—height of the liquid level inside the steel casing from the bottom of the casing;

[0020] —The change in buoyancy caused by water level changes (rising or falling) when the steel casing is temporarily fixed;

[0021] —Jack support force;

[0022] —The increased weight due to the extension of the steel casing.

[0023] The beneficial effects of this invention are:

[0024] 1. This invention uses a pre-set sealed water pump and flow meter to control the water volume inside the steel casing in real time, keeping it at the minimum water volume required to maintain a vertical floating state. This allows the casing to sink and be positioned, then be sealed and anchored with concrete. This solves the problem of installing ultra-long and ultra-heavy steel casings in mountainous reservoir areas where there are no large barges or lifting equipment. It also solves the problem of tilting caused by water level changes during the sinking and positioning of ultra-long and ultra-heavy steel casings, achieving good social and economic benefits.

[0025] 2. This invention summarizes the shortcomings of existing technologies and solves the problems of poor road conditions in mountainous areas, high cost of temporary road construction, inability to transport ultra-large diameter steel casings to bridge sites, and lifting and hoisting on water. It solves the problem of installing ultra-long and ultra-heavy steel casings in mountainous reservoir areas without large barges and lifting equipment, and solves the huge impact of water level changes on the sinking of steel casings. It can make the overall sinking of steel casings convenient, quick, safe, environmentally friendly, high-quality and efficient, saving construction time and costs by using jacks and water pumps. Attached Figure Description

[0026] Figure 1 This is a flowchart of the construction method steps in an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the steel casing in a vertical position in an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the steel casing fixing in an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of the steel casing anchorage in an embodiment of the present invention;

[0030] Figure 5 This is a top view of the drilling platform in an embodiment of the present invention. Detailed Implementation

[0031] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0032] Example

[0033] like Figure 1 As shown, a method for deep-water immersion and anchoring of ultra-long diameter steel casing includes the following steps:

[0034] The first step is to set up a drilling platform. At the designed location of the steel casing at the top of the riverbed, a pre-set anchoring position is set to penetrate 1m into the moderately weathered rock layer. By setting an anchoring position 1m into the moderately weathered rock layer, the stability of the steel casing after it sinks is ensured. The bottom of the steel casing is sealed and the top is open, so that the water pump can control the water volume inside the steel casing. I25 I-beams are used to temporarily fix the sealed steel casing to the drilling platform.

[0035] The second step involves cutting off the top steel plate of the steel casing, removing the top seal, placing a water pump, extending the steel casing to the designed length, and welding an I-beam with four 50t-class jacks underneath to share the weight of the steel casing. After cutting off the top steel plate and extending the steel casing, the water volume inside the steel casing is controlled by the water pump, and the weight of the steel casing is supported by the jacks, thus precisely controlling the sinking and floating and maintaining the stability of the steel casing. The steel casing is temporarily fixed to a position 1-1.5m above the drilling platform at the top opening of the steel casing using four I25 I-beams, with four 50t-class jacks placed under the I-beams to provide adjustable support for the steel casing.

[0036] The third step involves considering the changes in buoyancy caused by different water levels and the impact of rising water flow velocity. After developing a comprehensive plan for stabilizing the steel casing after removing the temporary fixation, the temporary fixation is removed. The water volume inside the steel casing is controlled by a water pump to maintain the steel casing in a vertical floating state. Water is continuously injected to gradually reduce the supporting force of the jacks until the jacks are unloaded and the steel casing is vertically balanced. At this point, the steel casing can maintain its balance and sink naturally by controlling the water volume inside it. Four 50t-class jacks are set up to provide support to maintain the steel casing in a vertical floating state when the weight of the steel casing increases or the water level drops. Especially during the process of removing the bottom plate of the steel casing, the proportion of the steel casing's weight borne by the jacks gradually increases until it is completely borne by the jacks.

[0037] Fourth, once the steel casing has sunk to the designated position, use a water pump to draw water from inside the steel casing to keep it vertically floating. Remove the bottom plate of the steel casing, and the weight of the steel casing will be borne by jacks. Pour concrete from the top of the casing towards the anchoring position, and gradually unload and remove the jacks. The steel casing will then naturally sink to the anchoring position and be anchored. Before the steel casing has completely sunk, pour concrete from the top of the steel casing to the pre-set anchoring position on the top of the riverbed to seal the bottom, ensuring the stability of the steel casing after it enters the anchoring position.

[0038] like Figure 3 and Figure 4 As shown, by setting an anchoring point 1m deep into the moderately weathered rock layer, the stability of the steel casing after sinking is ensured. The bottom of the steel casing is sealed and the top is open, so that the water pump can control the amount of water inside the steel casing.

[0039] like Figure 3 As shown, after cutting off the top steel plate and extending the steel casing, the water volume inside the steel casing is controlled by a water pump, and the weight of the steel casing is supported by a jack. This allows for precise control of the sinking and floating, and maintains the stability of the steel casing.

[0040] like Figure 5 As shown, the steel casing is temporarily fixed at a position 1-1.5m above the drilling platform by four I25 I-beams. Four 50t jacks are placed under the I-beams to provide adjustable support for the steel casing.

[0041] like Figure 3 As shown, considering that the weight of the steel casing, water level, and water flow velocity will all change after the steel casing is extended, the following measures were formulated to maintain the stability of the steel casing based on the assumed water level changes before the fixing was removed, taking into account different historical water level conditions:

[0042]

[0043] H – Depth of the steel casing submerged in water;

[0044] h—Height of the liquid level inside the steel casing from the bottom of the casing;

[0045] —The change in buoyancy caused by changes in water level (rising or falling) when the steel casing is temporarily fixed;

[0046] —The supporting force of the jack;

[0047] —The increased weight due to the extension of the steel casing.

[0048] like Figure 5 As shown, four 50t-class jacks are installed to provide support and keep the steel casing vertically floating when the weight of the steel casing increases or the water level drops. In particular, during the process of cutting off the bottom plate of the steel casing, the proportion of the steel casing's weight borne by the jacks gradually increases until it is completely borne by the jacks.

[0049] like Figure 4 As shown, before the steel casing is completely sunk, concrete is poured to seal the bottom of the pre-set anchorage position on the top of the riverbed from the top of the steel casing, so as to ensure the stability of the steel casing after it enters the anchorage position.

[0050] The embodiments described above are merely illustrative of specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for deep-water immersion and anchoring construction of ultra-long diameter steel casings, characterized in that, Includes the following steps: Step 1: Set up a drilling platform. At the position where the steel casing is placed on the top of the riverbed, pre-set an anchoring position that extends into the moderately weathered rock layer. Use welded I-beams to temporarily fix the sealed steel casing to the drilling platform. Step 2: Cut off the top steel plate of the steel casing, remove the top seal of the steel casing, place the water pump, and extend the steel casing to the designed length. Weld multiple jacks under the I-beam to share the weight of the steel casing. Step 3: Control the water volume inside the steel casing with a water pump to make the steel casing float or sink while maintaining vertical balance. At this time, release the temporary fixation. The steel casing can maintain balance by controlling the water volume inside the steel casing and be lowered using jacks. Step 4: After the steel casing sinks to the designated position and is a certain height from the riverbed, cut off the bottom plate of the steel casing. The weight of the steel casing is borne by the jack. Pour concrete from the top of the casing to the anchoring position. Lower the steel casing with the jack. The steel casing will sink naturally to the anchoring position and be anchored. Considering that the weight of the steel casing, water level, and water flow velocity will all change after the steel casing is extended, the following measures were formulated to maintain the stability of the steel casing based on the assumed range of water level changes and different historical water level conditions before the fixing was removed: ； H—Depth of the steel casing submerged in water; h—height of the liquid level inside the steel casing from the bottom of the casing; —The change in water level when the steel casing is temporarily fixed, i.e., the change in buoyancy caused by the rise or fall of the water level; —Jack support force; —The increased weight due to the extension of the steel casing.

2. The method for deep-water immersion and anchoring of ultra-long diameter steel casings according to claim 1, characterized in that, In step 1, the depth of the anchoring position is 0.5m-1.5m.

3. The method for deep-water immersion and anchoring of ultra-long diameter steel casings according to claim 1, characterized in that, The steel casing is temporarily fixed at a position 1m-1.5m above the drilling platform by four I25 I-beams. Four 50t jacks are placed under the I-beams to provide adjustable support for the steel casing.

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