Drilling installation and grouting integrated method for offshore wind power rock-socketed foundation

Abstract

The invention belongs to the field of offshore wind power, and discloses an offshore wind power rock-socketed foundation drilling installation and grouting integrated method which comprises the steps that a temporary installation platform is installed and arranged, and a main steel pipe pile penetrates through the top of a hard rock-soil layer in a sinking mode; installing a drilling machine, and suspending the secondary steel pipe pile; a drilling machine is lowered, drilling deslagging operation is conducted through the drilling machine, and drilling is continuously conducted to the designed depth of the hard rock-soil layer; lowering the secondary steel pipe pile to the hole bottom; grouting is conducted through a drill rod and a drill bit of the drilling machine, continuous grouting is kept, and grouting is stopped till the grouting liquid level is flush with the seabed surface; after the grouting material is solidified and aged, the main steel pipe pile and the secondary steel pipe pile are fixed through the hardened grouting material; and dismounting the drilling machine and the temporary mounting platform. According to the method, a previous pile casing structure is omitted, rock-socketed drilling and grouting integrated operation is adopted, multiple offshore operation procedures are omitted, the offshore operation efficiency is improved, and the rock-socketed construction cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of offshore wind power, and in particular to an integrated method for drilling, installing and grouting an offshore wind power rock-embedded foundation. Background Art

[0002] With the large-scale development of offshore wind power, the seabed in some sea areas is relatively complex, with shallow soft soil layer, shallow hard bedrock, and complex sea conditions. In some areas, there are quite a few seabed geology with shallow bedrock surface, which requires the use of rock-embedded pile foundation. The existing rock-embedded technology has many processes and many interfaces on the offshore working surface. It is necessary to lower the casing, pull out the casing, put on the drilling rig, lower the drilling rig, connect the grouting pipeline, and wait for 12-24 hours of aging and solidification before grouting. It requires a lot of ship machinery and equipment to cooperate. Moreover, the construction of rock-embedded pile foundations is mostly in typhoon-prone sea areas with few offshore operation windows. In order to meet the construction period requirements, a large number of ship machinery and equipment have to be invested, which has brought huge pressure on the cost reduction and efficiency improvement of offshore wind power. The long construction period and high cost of offshore rock-embedded piles have become the industry pain points that need to be solved urgently.

[0003] The present application proposes an integrated method for drilling, installing and grouting an offshore wind power rock-embedded foundation, which eliminates the previous casing structure and adopts integrated rock-embedded drilling and grouting operations, thereby eliminating many offshore operation procedures, improving offshore operation efficiency and reducing rock-embedded construction costs. Summary of the invention

[0004] The object of the present invention is to provide an integrated method for drilling, installing and grouting an offshore wind power rock-embedded foundation, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: An integrated method for drilling, installing and grouting an offshore wind power rock-embedded foundation comprises the following steps: Step 1: Install a temporary installation platform at the predetermined rock embedding location and sink the main steel pipe piles into the top of the hard rock and soil layer; Step 2: Install a drilling rig on the upper end of the temporary installation platform, suspend a secondary steel pipe pile, the outer diameter of the secondary steel pipe pile is smaller than the inner diameter of the main steel pipe pile, and the lower side wall of the secondary steel pipe pile has a grouting side hole; Step 3: Lower the drilling rig, use the drilling rig to perform drilling and slag removal operations, and continue drilling to the designed depth of the hard rock and soil layer; Step 4: Lower the secondary steel pipe pile to the bottom of the hole, and the top position of the secondary steel pipe pile after lowering is higher than the bottom position of the main steel pipe pile; Step 5: Grouting is performed through the drill rod and drill bit of the drilling rig. The grouting material flows into the secondary steel pipe pile and flows to the outside of the secondary steel pipe pile side wall through the grouting side holes on the secondary steel pipe pile. Continuous grouting is maintained until the grouting liquid surface is flush with the seabed surface and then the grouting is stopped; Step 6: Retract the drilling rig, wait for the grouting material to solidify and age, and fix the main steel pipe pile and the secondary steel pipe pile with the hardened grouting material; Step 7: Dismantle the drilling rig and temporary installation platform.

[0006] Furthermore, in the step 1, vibration or impact piling is used to sink the main steel pipe piles to the top of the hard rock and soil layer.

[0007] Furthermore, the drilling rig includes a drill bit, a drill rod, a drill bit drive and fixing frame, a compressed air valve, a grouting valve and a slag discharge valve. The drill bit drive and fixing frame are installed on a temporary installation platform. The drill rod is connected to the drill bit drive and fixing frame. The drill bit is arranged at the lower end of the drill rod. The drill rod has a drill rod main channel and a drill rod secondary channel. The drill bit has a drill bit channel connected to the drill rod main channel. The drill arm of the drill bit has a drill arm channel connected to the drill rod secondary channel. The grouting valve and the slag discharge valve are respectively connected to the drill rod main channel of the drill rod through pipelines, and the slag discharge valve is connected to the drill rod secondary channel of the drill rod through a pipeline.

[0008] Furthermore, when drilling in step three, the drill rod is extended to the overburden layer, the drill arm of the drill bit is opened, the compressed air valve and the slag discharge valve are opened, the grouting valve is in a closed state, and the drilling and slag discharge operations are started. The compressed air is discharged into the borehole through the drill arm to squeeze the seawater and silt, so that the seawater and silt are discharged through the drill bit channel, the drill rod main channel and the slag discharge valve.

[0009] Furthermore, during the grouting in step five, the compressed air valve and the slag discharge valve are closed, and the grouting valve is opened. The grouting material flows into the secondary steel pipe pile through the grouting valve, the drill rod main channel, and the drill bit channel, and flows to the outside of the secondary steel pipe pile side wall through the grouting side holes on the secondary steel pipe pile.

[0010] Furthermore, in step five, during the grouting process, the drill bit of the drilling rig is always kept no higher than the grouting surface by no more than 50 centimeters.

[0011] Furthermore, in step six, the solidification and aging time of the grouting material is 12 to 24 hours.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 1) In the past, after drilling, the drilling rig had to be dismantled and the pipelines had to be connected before grouting could be carried out. The present invention is an integrated drilling and grouting operation, which only requires a simple valve operation to complete the switch from drilling to grouting; 2) In the past, the drilling hole needed casing protection, and the casing had to be removed after the operation. The present invention eliminates the casing, and the main steel pipe pile can function as the casing to ensure that the covering soil layer does not collapse during the drilling and grouting process; 3) Compared with the previous methods, the present invention has fewer offshore operation processes and shorter connection time between processes, which can improve offshore operation efficiency and reduce construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a flow chart of the present invention.

[0014] Figure 2 This is one of the construction schematic diagrams of the present invention.

[0015] Figure 3 This is the second construction schematic diagram of the present invention.

[0016] Figure 4 This is the third construction schematic diagram of the present invention.

[0017] Figure 5 This is the fourth construction schematic diagram of the present invention.

[0018] Figure 6 This is the fifth construction schematic diagram of the present invention.

[0019] Figure 7 This is the sixth construction schematic diagram of the present invention.

[0020] Figure 8 This is the seventh construction schematic diagram of the present invention.

[0021] Fig. 9 This is the eighth construction schematic diagram of the present invention.

[0022] Fig.10 This is the ninth construction schematic diagram of the present invention.

[0023] In the figure: temporary installation platform 1, main steel pipe pile 2, secondary steel pipe pile 3, drilling rig 4, drill bit 400, drill rod 401, drill bit drive and fixing frame 402, compressed air valve 403, grouting valve 404, slag discharge valve 405, drill rod main channel 406, drill rod secondary channel 407, drill arm 408, seawater layer 5, overburden layer 6, hard rock and soil layer 7, grouting area 8. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] See also Figure 1-Figure 10 , an integrated method for drilling, installing and grouting an offshore wind power rock-embedded foundation, comprising the following steps: Step 1: Install a temporary installation platform 1 at the predetermined rock embedding position, and sink the main steel pipe pile 2 into the top of the hard rock and soil layer 7 by vibration or impact piling.

[0026] Step 2: If Figure 2 and Figure 3 As shown, relying on the temporary installation platform 1, the secondary steel pipe piles 3 are sequentially suspended, and the drilling rig 4 is installed and fixed on the temporary installation platform 1. The drilling rig 4 includes a drill bit 400, a drill rod 401, a drill bit drive and fixing frame 402, a compressed air valve 403, a grouting valve 404 and a slag discharge valve 405. The drill bit drive and fixing frame 402 are installed on the temporary installation platform 1, the drill rod 401 is connected to the drill bit drive and fixing frame 402, and the drill bit 400 is set on the drill rod 4 01, the drill rod 401 has a main drill rod channel 406 and a secondary drill rod channel 407, the grouting valve 404 and the slag discharge valve 405 are respectively connected to the main drill rod channel 406 of the drill rod 401 through a pipeline, the slag discharge valve 405 is connected to the secondary drill rod channel 407 of the drill rod 401 through a pipeline, the main drill rod channel 406 is connected to the drill bit channel of the drill bit 400, and the drill rod secondary channel 407 is connected to the drill arm channels on the drill arms 408 on both sides of the drill bit 400. The drill arms 408 of the drill bit 400 are in a retracted state and pass through the secondary steel pipe pile 3, and the grouting valve 404, the slag discharge valve 405, and the compressed air valve 403 are in a closed state. The outer diameter of the secondary steel pipe pile 3 is smaller than the inner diameter of the main steel pipe pile 2, and the lower side wall of the secondary steel pipe pile 3 has a grouting side hole.

[0027] Step 3: If Figure 4 and Figure 5 As shown, the drill rod 401 extends to the overburden layer 6, the drill arm 408 of the drill bit 400 is opened, the compressed air valve 403 is opened (the compressed air valve 403 is connected to the compressed air), the slag discharge valve 405 is opened, the grouting valve 404 is in a closed state, and the drilling and slag discharge operation begins. The drilling operation is maintained, and the drill bit 400 continues to drill to the designed depth of the hard rock layer 7. When drilling, the compressed air is discharged into the borehole through the compressed air valve 403, the drill rod auxiliary channel 407, and the drill arm channel to squeeze the seawater and sediment, so that the seawater and sediment are discharged through the drill bit channel, the drill rod main channel and the slag discharge valve.

[0028] Step 4: If Figure 6 As shown, the drill bit 400 retracts the drill arm 408 inward, and lowers the secondary steel pipe pile 3 to the bottom of the hole. After being lowered, the top position of the secondary steel pipe pile 3 is higher than the bottom position of the main steel pipe pile 2.

[0029] Step 5: If Figure 7As shown, close the compressed air valve 403 and the slag discharge valve 405, open the grouting valve 404 (connect to the high-pressure grouting system), and the grouting material flows into the secondary steel pipe pile 3 and the side wall through the grouting valve 404, the drill pipe main channel 406, and the drill bit channel. The grouting material flows between the secondary steel pipe pile 3 and the rock wall through the grouting side holes of the secondary steel pipe pile 3. During the grouting process, always keep the drill bit 400 no higher than the grouting surface by no more than 50 cm. Figure 8 As shown, continuous grouting is maintained until the grouting liquid surface is flush with the seabed surface, and the grouting valve 404 is closed to stop grouting.

[0030] Step 6: If Fig. 9 As shown, the drill bit 400 is retracted, and the grouting material is solidified and aged for 12 to 24 hours, and the main steel pipe pile 2 and the secondary steel pipe pile 3 are fixed by the hardened grouting material.

[0031] Step 7: If Fig.10 As shown, the drilling rig 4 and the temporary installation platform 1 are removed, and the drilling and grouting operation at the next location is carried out.

[0032] It should be noted that all the drill rods 401 used in the present invention are of a multi-section spliced ​​structure. During the process of lowering the drill bit 400, the drill bit 400 is lowered by continuously lengthening the drill rod 401. When the drill bit 400 is recovered, it is achieved by continuously shortening the drill rod 401. This is a well-known technology in the field of drilling rigs and will not be elaborated on.

[0033] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An integrated method for drilling, installing and grouting offshore wind power rock-embedded foundation, characterized in that: The following steps are involved: Step 1: Install a temporary installation platform at the predetermined rock embedding location and sink the main steel pipe piles into the top of the hard rock and soil layer; Step 2: Install a drilling rig on the upper end of the temporary installation platform, suspend a secondary steel pipe pile, the outer diameter of the secondary steel pipe pile is smaller than the inner diameter of the main steel pipe pile, and the lower side wall of the secondary steel pipe pile has a grouting side hole; Step 3: Lower the drilling rig, use the drilling rig to perform drilling and slag removal operations, and continue drilling to the designed depth of the hard rock and soil layer; Step 4: Lower the secondary steel pipe pile to the bottom of the hole, and the top position of the secondary steel pipe pile after lowering is higher than the bottom position of the main steel pipe pile; Step 5: Grouting is performed through the drill rod and drill bit of the drilling rig. The grouting material flows into the secondary steel pipe pile and flows to the outside of the secondary steel pipe pile side wall through the grouting side holes on the secondary steel pipe pile. Continuous grouting is maintained until the grouting liquid surface is flush with the seabed surface and then the grouting is stopped; Step 6: Retract the drilling rig, wait for the grouting material to solidify and age, and fix the main steel pipe pile and the secondary steel pipe pile with the hardened grouting material; Step 7: Dismantle the drilling rig and temporary installation platform.

2. The integrated method for drilling, installing and grouting an offshore wind power rock-embedded foundation according to claim 1, characterized in that: In the step 1, the main steel pipe pile is sunk to the top of the hard rock and soil layer by means of vibration or impact piling.

3. The integrated method for drilling, installing and grouting an offshore wind power rock-embedded foundation according to claim 1, characterized in that: The drilling rig includes a drill bit, a drill rod, a drill bit drive and fixing frame, a compressed air valve, a grouting valve and a slag discharge valve. The drill bit drive and fixing frame are installed on a temporary installation platform. The drill rod is connected to the drill bit drive and fixing frame. The drill bit is arranged at the lower end of the drill rod. The drill rod has a drill rod main channel and a drill rod secondary channel. The drill bit has a drill bit channel connected to the drill rod main channel. The drill arm of the drill bit has a drill arm channel connected to the drill rod secondary channel. The grouting valve and the slag discharge valve are respectively connected to the drill rod main channel of the drill rod through pipelines, and the slag discharge valve is connected to the drill rod secondary channel of the drill rod through a pipeline.

4. The integrated method for drilling, installing and grouting an offshore wind power rock-embedded foundation according to claim 3, characterized in that: When drilling in step three, the drill rod is extended to the overburden layer, the drill arm of the drill bit is opened, the compressed air valve and the slag discharge valve are opened, the grouting valve is in a closed state, and the drilling and slag discharge operations are started. The compressed air is discharged into the borehole through the drill arm to squeeze the seawater and silt, so that the seawater and silt are discharged through the drill bit channel, the drill rod main channel and the slag discharge valve.

5. The integrated method for drilling, installing and grouting an offshore wind power rock-embedded foundation according to claim 3, characterized in that: During the grouting in step five, the compressed air valve and the slag discharge valve are closed, and the grouting valve is opened. The grouting material flows into the secondary steel pipe pile through the grouting valve, the drill rod main channel, and the drill bit channel, and flows to the outside of the secondary steel pipe pile side wall through the grouting side holes on the secondary steel pipe pile.

6. The integrated method for drilling, installing and grouting an offshore wind power rock-embedded foundation according to claim 1, characterized in that: In step 5, during the grouting process, the drill bit of the drilling rig is always kept no higher than the grouting surface by no more than 50 centimeters.

7. The integrated method for drilling, installing and grouting an offshore wind power rock-embedded foundation according to claim 1, characterized in that: The solidification and aging time of the grouting material in step six is ​​12 to 24 hours.

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