Hole-opening and block-falling-preventing equipment for freezing and reinforcing machine shell of river bottom shield tunneling machine and construction method of hole-opening and block-falling-preventing equipment

Abstract

The invention discloses equipment for preventing chipping by opening holes in a freezing and reinforcing machine shell of a river bottom shield tunneling machine and a construction method of the equipment, and relates to the field of freezing construction when a shield tunneling machine stops to freeze and reinforce stratum.The equipment comprises a hollow-core drill rod, and a tooth-shaped drill bit is arranged at the head of the hollow-core drill rod; in order to realize pipe stabilization and coring of the hollow-core drill rod, the outer side of the circumference of the hollow-core drill rod is sleeved with an orifice pipe, and the outer side of the circumference of the orifice pipe is sleeved with a sealing sleeve, so that leakproofness in the drilling process is guaranteed, and pressure loss caused by communication between the shield tunneling machine and the outside is prevented; a water injection hole is formed in the tail of the hollow drill rod, and an external cooling water pipe is arranged in the water injection hole so that cooling water can be injected to cool the tooth-shaped drill bit. The bayonet is additionally arranged in the orifice pipe, and in the drilling process of the shield tunneling machine shell, the shield tunneling machine shell which is drilled down is prevented from falling into an external stratum to clamp drilling of a drill bit in the later period; and the drilled shield tunneling machine shell is pushed back to the interior of the shield tunneling machine through external water and soil pressure, and the purposes of taking out the shield shell and preventing the shield shell from falling into an external stratum are achieved.

Description

Technical Field

[0001] The present invention relates to the field of seasonal freezing construction for ground freezing and reinforcement during shield machine shutdown, and particularly to a device for preventing block falling during hole opening in the casing of a shield machine for freezing and reinforcement under the river and its construction method. Background Art

[0002] At present, the construction of highway shield tunnels is developing towards larger diameters, deeper burial depths, and longer distances. Especially for long shield tunnels crossing rivers, seas, etc., the extremely long tunnels continuously challenge the performance of shield machine equipment. For the construction of ultra-long shield tunnels, there are usually two ideas at present. One is to improve the service performance of key equipment of shield machines, such as main drives, bearings, seals, cutter heads, tail brushes, pumps, pipelines, etc.; the other is to excavate a foundation pit on a water surface island and use two shield machines to drive in opposite directions to reduce the driving distance of a single shield machine.

[0003] Both of the above two mainstream ideas have their corresponding problems. It is very difficult for the current scientific and technological strength to significantly improve the service performance of shield key equipment in a short period of time; when there is no island in the water area to be driven through, artificial island building is still required, with too high costs and too long construction periods. In addition to the above two methods, there are also cases where one shield machine is launched from each bank and drives towards each other for docking underwater. This construction method has relatively high risks and requires stable strata or corresponding technologies to keep the strata stable during the underwater docking stage of the shield.

[0004] Currently, the most widely used technology for stabilizing the strata is freezing. By drilling freezing holes in the shield machine and inserting freezing pipes into the external strata, the brine or liquid nitrogen in the freezing pipes continuously circulates in the pipes to cool the strata, and ultimately achieve the purpose of hardening and stabilizing the strata.

[0005] For example, the patent with application number CN208763610U discloses a core drilling device for preventing drill dropping during geological drilling. By adding a connecting device between the drill pipe and the core barrel, when the core barrel breaks during the drilling process, the core barrel still remains connected to the upper drill pipe, preventing the core barrel from getting stuck or falling into the drill hole, thereby avoiding the occurrence of drill dropping and improving the hole forming rate of the drill hole. Its main idea is to transform the drill pipe to form a groove for embedding a sleeve, and the sleeve and the core barrel are connected by a connecting rod. When the core barrel is damaged or breaks during the drilling process, the core barrel can still be connected to the drill pipe through the connecting rod, enabling the damaged core barrel to be safely withdrawn from the drill hole, thereby improving the hole forming rate of geological drilling. The core drilling device for preventing drill dropping mainly considers preventing drill dropping during the design, that is, when the core barrel breaks, it can still be connected to the drill pipe through the externally arranged connecting rod. However, there is no measure for preventing the core sample taken out by the core rod from falling. At the same time, the core drilling device for preventing drill dropping only introduces the device itself and does not synchronously introduce its construction method.

[0006] For another example, the utility model with the application number CN208918499 discloses a salvage tool for debris in the directional drilling landing and dragging borehole of a submarine pipeline. This salvage tool installs a sheet-shaped anti-falling spiral inside the submarine dragging pipe for qualitative drilling, and connects the sheet-shaped spiral to the dragging pipe through the connecting thread at the top of the pipe. When constructing the submarine directional drilling dragging pipe, the sheet-shaped spiral can rotate to lift the debris inside the pipe, achieving the purpose of preventing drill jamming. The concept of this salvage tool mainly considers how to prevent debris on the seabed from jamming the drag rod, and clears the borehole by setting the rotating lifting of the sheet-shaped spiral structure. This method can play a certain role in cleaning fine gravel. However, when encountering some special structures (such as garbage bags, ropes, slightly larger stones, etc.), the structure is easily jammed by the spiral structure, failing to achieve the intended effect. At the same time, the spiral structure in this device uses sheet materials, and there are also problems with its structural durability and stiffness. Finally, this device cannot be used to clean debris close to the inner diameter of the drag rod, and the specifications of the debris it removes are related to the opening size of the spiral structure. The gentler the spiral, the larger the size of the debris that can be cleaned, but the longer the spiral length required for lifting. The steeper the spiral, the smaller the size of the debris that can be cleaned, but the worse the effect of lifting the debris.

[0007] Generally speaking, the existing technologies mainly focus on the design of preventing drill dropping, and there is less technology involved in how to protect the retrieved core samples or prevent them from falling. In the design of preventing drill dropping, the current mainstream design idea is to set devices such as bayonets or traction locks on the drill pipe. Once the drill bit drops into the hole, it can be quickly salvaged to avoid drill bit loss and hole plugging. In actual operation, there will be certain problems in the existing technologies, such as difficulty in removing the drill bit, drill jamming, etc. Summary of the Invention

[0008] Based on this, it is necessary to provide an anti-drop block equipment for opening holes in the frozen reinforcement casing of a river-bottom shield machine and its construction method in view of the above technical problems.

[0009] In the first aspect, the present invention provides an anti-drop block equipment for opening holes in the frozen reinforcement casing of a river-bottom shield machine. This equipment includes a hollow drill pipe, and a toothed drill bit is provided at the head of the hollow drill pipe; in order to achieve the pipe stabilization and core sampling of the hollow drill pipe, a hole-opening pipe is sleeved on the outer circumference of the hollow drill pipe, and a sealing sleeve is sleeved on the outer circumference of the hole-opening pipe to ensure the tightness of the drilling process and prevent the shield machine from losing pressure due to communication with the outside; a water injection hole is opened at the tail of the hollow drill pipe, and an external cooling water pipe is arranged inside the water injection hole to inject cooling water to cool the toothed drill bit.

[0010] Furthermore, the length of the hole-opening pipe is less than the length of the hollow drill pipe, and the length of the hole-opening pipe is greater than the length of the sealing sleeve; a plurality of hoop rings are welded inside the hole-opening pipe, the material of the hoop rings is the same as that of the hole-opening pipe, and the inner diameter of the hoop rings is the same as the outer diameter of the hollow drill pipe to ensure the insertion fit between the hollow drill pipe and the hoop rings.

[0011] Further, the toothed drill bit adopts 10 alloy teeth and is used to rotate and cut the steel shell of the shield machine driven by the rotating head at the tail of the hollow drill pipe.

[0012] Further, flange plates are provided at both ends of the tail of the orifice pipe and the sealing sleeve; the flange plate at the head of the sealing sleeve is fixedly welded to the inner wall of the shield machine shell for positioning the core-taking position; a number of equally spaced connecting bolt holes are opened on the circumferential outer edge of the flange plate at the tail of the sealing sleeve, and the connecting bolt holes and the flange plate at the tail of the orifice pipe are connected by long bolts.

[0013] Further, one side of the flange plate at the tail of the sealing sleeve is connected with a tail-end cover plate through a connecting lock. A polyurethane injection hole is opened at the center position of the tail-end cover plate. After the core is taken out, the tail-end cover plate is covered, and polyurethane is injected through the polyurethane injection hole to prevent the connection of the internal and external pressures of the shield machine.

[0014] Further, after the tail-end cover plate is covered, the outside of the orifice pipe is wound with packing hemp for sealing inside the sealing sleeve.

[0015] In a second aspect, the present invention also provides a construction method for preventing block falling during hole opening in the frozen reinforced machine shell of a river-bottom shield machine. The construction method includes:

[0016] S1. Mark the part to be opened on the shield machine shell, and sequentially install and fix the sealing sleeve, the orifice pipe and the hollow drill pipe to realize the connection of the equipment structural parts;

[0017] S2. Start the core drill, inject cooling water through the external cooling water pipe to cool the toothed drill bit, control the insertion and drilling depth of the orifice pipe, and drill through circulation until the predetermined depth is reached, then stop drilling and withdraw the hollow drill pipe;

[0018] S3. Take out the drilled shield machine shell, and after withdrawing the hollow drill pipe, seal the sealing sleeve and the orifice pipe.

[0019] Further, marking the part to be opened on the shield machine shell and sequentially installing and fixing the sealing sleeve, the orifice pipe and the hollow drill pipe to realize the connection of the equipment structural parts includes:

[0020] S11. At the part to be opened on the shield machine shell, use color paint to mark the center point position;

[0021] S12. Press the flange plate at the head of the sealing sleeve against the inner wall of the shield machine shell and then weld;

[0022] S13. Firmly connect the flange plate at the tail of the orifice pipe and the flange plate at the tail of the sealing sleeve with long bolts, and tighten and fix with nuts on both sides of the long bolts;

[0023] S14. Insert the hollow drill pipe into the inner part of the orifice pipe to complete the positioning, connect the rotary head to the tail of the hollow drill pipe, and connect the external cooling water pipe to the water injection hole.

[0024] Further, start the core drilling rig, inject cooling water by using the external cooling water pipe to cool the toothed drill bit, control the insertion and drilling depth of the orifice pipe, and drill in a cycle until the predetermined depth is reached. Stop drilling and withdraw the hollow drill pipe, which includes:

[0025] S21. Start the rotary head at the tail of the hollow drill pipe. As the hollow drill pipe drills, start injecting cooling water through the external cooling water pipe. The cooling water flows back through the gap between the orifice pipe and the hollow drill pipe and overflows from the tail of the orifice pipe into the shield machine.

[0026] S22. When the hollow drill pipe drills a preset starting distance, stop the machine and loosen the long bolts connecting the orifice pipe and the sealing sleeve. Insert the orifice pipe to the depth where the hollow drill pipe has drilled, and cycle in turn until the hollow drill pipe drills to the last preset end distance of the shield machine shell.

[0027] S23. When the hollow drill pipe reaches the preset end distance, close the external cooling water pipe and continue drilling by using the coolant remaining inside the orifice pipe to the hollow drill pipe. When the preset end distance is drilled, the hollow drill pipe contacts the external formation and continues to drill a preset formation distance into the external formation, and use the external water and soil pressure to jack back the cut shield machine shell.

[0028] S24. When the hollow drill pipe reaches the preset formation distance, stop drilling and withdraw the hollow drill pipe.

[0029] Further, take out the cut shield machine shell, and after withdrawing the hollow drill pipe, seal the sealing sleeve and the orifice pipe, which includes:

[0030] S31. When the hollow drill pipe and the core sample are completely taken out, close the end cover plate connected to the flange at the tail of the sealing sleeve and tightly fix it with bolts.

[0031] S32. Inject foaming polyurethane into the orifice pipe and the sealing sleeve through the polyurethane injection hole at the center of the end cover plate.

[0032] S33. Wind the tallow packing around the outside of the orifice pipe in circles, and after winding multiple layers, stuff it into the sealing sleeve until it is full without gaps to achieve sealing.

[0033] The beneficial effects of the present invention are:

[0034] 1. By adding a bayonet in the orifice pipe, during the drilling process of the shield machine shell, it can prevent the cut shield machine shell from falling into the external formation and getting stuck in the subsequent drilling of the drill bit; at the same time, after the drilling length reaches the thickness of the shield shell, the hollow drill pipe continues to drill into the formation for 20 cm and then stops drilling. Through the external water and soil pressure, the drilled shield machine shell is pushed back into the shield machine to achieve the purpose of removing the shield shell and preventing it from falling into the external formation and affecting the subsequent drilling of the freezing pipe.

[0035] 2. By designing the hoop structure, it plays two roles: ① During the process of the drill rig driving the hollow drill pipe to drill and take core in the steel shell of the shield machine, there will be a large degree of irregular jitter, and these irregular jitters are likely to cause the hollow drill pipe to deviate during the drilling process; after adding the hoop, it can restrain the hollow drill pipe so that it can always maintain the set line during the drilling process. ② During the process of the hollow drill pipe drilling through the shield shell to take core, the removed shield machine shell will be pushed back under the action of the external water and soil pressure. At this time, the hollow drill pipe will carry external sediment during the retraction process, resulting in the deviation and slipping of the taken core sample into the external formation, and the core sampling fails. By adding three hoops in the orifice pipe, since the inner diameter of the hoop is basically the same as the outer diameter of the core sample, even if the core sample deviates in the core sampling pipe, it will still be blocked by the hoop and will not slip into the external formation.

[0036] 3. The operation of the present invention is simple and convenient. Only a bayonet needs to be set in the drill rig to clamp the cut shield shell. At the same time, after the drilling is completed, stop for 5 - 10 s and then lift the drill rig; moreover, it has a wide range of applications, not only applicable to opening holes in the shield machine, but also applicable to the construction of preventing falling during the opening of other underground structures; in addition, the present invention has good use effects. Since the modification of the existing drill rig is less, it will not affect the use of the drill rig; at the same time, the design of adding a bayonet and the improved construction process can ensure the complete removal of the steel shell of the shield machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0038] Figure 1 is a schematic connection diagram of a hollow drill pipe, a sealing sleeve and an orifice pipe in an anti-drop block device for opening a hole in the frozen reinforcement machine shell of a river-bottom shield machine according to an embodiment of the present invention;

[0039] Figure 2 is a schematic diagram of a sealing sleeve and a hollow drill pipe in an anti-drop block device for opening a hole in the frozen reinforcement machine shell of a river-bottom shield machine according to an embodiment of the present invention;

[0040] Figure 3It is a top view of the relative relationship among the hollow core drill pipe, the orifice pipe and the external sealing sleeve of the anti-falling block equipment for opening holes in the frozen reinforcement casing of the subaqueous shield machine according to an embodiment of the present invention;

[0041] Figure 4 It is a top view of the relative relationship between the hollow core drill pipe and the orifice pipe of the anti-falling block equipment for opening holes in the frozen reinforcement casing of the subaqueous shield machine according to an embodiment of the present invention;

[0042] Figure 5 It is a front view of the front end of the orifice pipe of the anti-falling block equipment for opening holes in the frozen reinforcement casing of the subaqueous shield machine according to an embodiment of the present invention;

[0043] Figure 6 It is a front view of the front end of the sealing sleeve of the anti-falling block equipment for opening holes in the frozen reinforcement casing of the subaqueous shield machine according to an embodiment of the present invention;

[0044] Figure 7 It is a schematic diagram of drilling in the inner shell of the shield machine of the anti-falling block equipment for opening holes in the frozen reinforcement casing of the subaqueous shield machine according to an embodiment of the present invention;

[0045] Figure 8 It is a schematic diagram of the end cover plate at the tail end of the sealing sleeve of the anti-falling block equipment for opening holes in the frozen reinforcement casing of the subaqueous shield machine according to an embodiment of the present invention

[0046] Figure 9 It is an analysis of the force on the steel shell during the drilling process of the improved hollow core drill pipe according to an embodiment of the present invention;

[0047] Figure 10 It is a schematic diagram of the plum blossom drilling sequence of multiple drilling rigs according to an embodiment of the present invention;

[0048] Figure 11 It is an analysis of the force on the steel shell during the drilling process of the drill pipe according to an embodiment of the present invention;

[0049] Figure 12 It is a flowchart of the construction method for preventing falling blocks when opening holes in the frozen reinforcement casing of the subaqueous shield machine according to an embodiment of the present invention.

[0050] Reference numerals in the drawings: 1, hollow core drill pipe; 2, toothed drill bit; 3, orifice pipe; 4, sealing sleeve; 5, water injection hole; 6, external cooling water pipe; 7, hoop; 8, flange; 9, connecting bolt hole; 10, connecting lock; 11, end cover plate; 12, polyurethane injection hole; 13, grease packing. Detailed implementation manners

[0051] In order to make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0052] Please refer to Figures 1-8 , a kind of equipment for preventing block dropping in the opening of the frozen reinforcement casing of a river-bottom shield machine is provided. This equipment includes a hollow drill pipe 1, and a toothed drill bit 2 is arranged at the head of the hollow drill pipe 1; in order to realize the pipe stabilization and core extraction of the hollow drill pipe 1, a hole mouth pipe 3 is sleeved on the outer circumference of the hollow drill pipe 1, and a sealing sleeve 4 is sleeved on the outer circumference of the hole mouth pipe 3 to ensure the tightness of the drilling process and prevent the shield machine from losing pressure due to communication with the outside; a water injection hole 5 is opened at the tail of the hollow drill pipe 1, and an external cooling water pipe 6 is arranged inside the water injection hole 5 to inject cooling water to cool the toothed drill bit 2.

[0053] In one embodiment, the length of the hole mouth pipe 3 is less than the length of the hollow drill pipe 1, and the length of the hole mouth pipe 3 is greater than the length of the sealing sleeve 4; a plurality of hoop 7s are welded inside the hole mouth pipe 3, the material of the hoop 7 is the same as that of the hole mouth pipe 3, and the inner diameter of the hoop 7 is the same as the outer diameter of the hollow drill pipe 1 to ensure the insertion fit between the hollow drill pipe 1 and the hoop 7.

[0054] It should be noted that, as Figures 1-3 can be seen, the hollow drill pipe 1 is of a hollow structure, and the head is composed of an alloy toothed drill bit 2. The hole mouth pipe 3 is arranged outside the hollow drill pipe 1. The hole mouth pipe 3 serves as a pipe stabilization device and a core extraction device for the hollow drill pipe 1, and its length is shorter than that of the hollow drill pipe 1 and longer than that of the outermost sealing sleeve 4. The hole mouth pipe 3 is made of Q355B steel plate and is rolled, as Figures 3-5 shown, and the hollow drill pipe 1 is sleeved inside. In order to prevent the core sample of the shield machine shell after drilling from falling into the external formation, and at the same time to limit the deviation of the hollow drill pipe 1 during drilling due to shaking, three circles of hoop 7s are welded inside the hole mouth pipe 3. The material of the hoop 7 is the same as that of the hole mouth pipe 3, and the thickness of the hoop 7 is 2 - 3 cm. The inner diameter of the hoop 7 is consistent with the outer diameter of the hollow drill pipe 1 to ensure that the hollow drill pipe 1 can just be inserted into the hoop.

[0055] In one embodiment, the toothed drill bit 2 adopts 10-lobe alloy teeth and is used to rotate and cut the steel shell of the shield machine under the drive of the rotating head at the tail of the hollow drill pipe 1.

[0056] It should be noted that, as Figure 3As can be seen from the top view of the relative relationship between the hollow drill pipe 1 and the orifice pipe 3, the high-strength alloy toothed drill bit has a total of 10 alloy teeth, which rotate and cut the steel shell of the shield machine driven by the rotating head at the tail of the hollow drill pipe 1. Except for the alloy teeth, the rest of the hollow drill pipe 1 is made of Q355B steel. In order to reduce the large amount of heat generated by the strong friction between the alloy teeth and the steel shell of the shield machine during drilling, causing alloy softening or fatigue and affecting the core sampling efficiency, an external cooling water pipe 6 is connected to the opening at the tail of the core sampling drill, and cooling water is injected into the head of the core sampling drill to cool the drill bit.

[0057] In one embodiment, flange plates 8 are provided at both ends of the tail of the orifice pipe 3 and the sealing sleeve 4; the flange plate 8 at the head of the sealing sleeve 4 is fixed to the inner wall of the shield machine shell by welding for positioning the core sampling position; a number of equally spaced connecting bolt holes 9 are provided on the circumferential outer edge of the flange plate 8 at the tail of the sealing sleeve 4, and long bolts are used to connect between the connecting bolt holes 9 and the flange plate 8 at the tail of the orifice pipe 3.

[0058] It should be noted that as Figures 1-2 shown, on the outermost layer of the hollow drill pipe 1, to ensure the tightness of the drill during drilling, the outermost part of the device is the sealing sleeve 4, which is rolled from Q355B steel and is mainly used to connect the shield machine shell and the orifice pipe 3 to prevent the drill from losing pressure due to connection with the outside of the shield machine during drilling. There are flange plates 8 at both the front and rear of the sealing sleeve 4.

[0059] As Figure 6 shown, the flange plate 8 at the front of the sealing sleeve 4 is closely attached to the inner shell of the shield machine, and there are no bolt holes on it. The sealing sleeve 4 is fixed to the inner wall of the shield machine shell by welding for positioning the core sampling position. As Figure 8 shown, there are connecting bolt holes 9 on the flange plate 8 at the tail of the sealing sleeve 4, which are bolt-connected to the flange plate 8 at the tail of the orifice pipe 3. Since the length of the orifice pipe 3 is appropriately longer than that of the sealing sleeve 4, long bolts are used for connection. At the same time, during core sampling construction, the length of the bolt can also be adjusted to insert the orifice pipe 3 between the shield machine shell and the core sample taken out.

[0060] In one embodiment, one side of the flange plate 8 at the tail of the sealing sleeve 4 is connected with a tail-end cover plate 11 through a connecting lock 10. A polyurethane injection hole 12 is provided at the center of the tail-end cover plate 11. After the core is taken out, the tail-end cover plate 11 is covered, and polyurethane is injected through the polyurethane injection hole 12 to prevent the connection of internal and external pressures of the shield machine; after the tail-end cover plate 11 is covered, a grease packing 13 is wound around the outside of the orifice pipe 3 to achieve the sealing inside the sealing sleeve 4.

[0061] It should be noted that a tail end cover plate 11 is also connected to the flange plate 8 at the tail of the sealed sleeve 4. There is a polyurethane injection hole 12 on the tail end cover plate 11. After the core drill is withdrawn after core sampling, the tail end cover plate 11 is immediately covered, and polyurethane is injected to seal the hole to prevent the connection of the internal and external pressures of the shield machine. Finally, a packing of tallow 13 is wound around the outer side of the orifice tube 3 in circles. After winding multiple layers, it is stuffed into the sealed sleeve 4 until it is full without gaps for sealing purposes.

[0062] Please refer to Figure 12 , the present invention also provides a construction method for preventing block dropping during hole opening in the frozen reinforced housing of a subaqueous shield machine. This construction method includes:

[0063] S1. Mark the position to be drilled on the shield machine housing, and sequentially install and fix the sealed sleeve 4, the orifice tube 3, and the hollow drill rod 1 to realize the connection of the equipment structural components;

[0064] S2. Start the core drill, inject cooling water through the external cooling water pipe 6 to cool the toothed drill bit 2, control the insertion and drilling depth of the orifice tube 3, and drill through circulation until the predetermined depth is reached, then stop drilling and withdraw the hollow drill rod 1;

[0065] S3. Take out the drilled shield machine housing, and after withdrawing the hollow drill rod 1, seal the sealed sleeve 4 and the orifice tube 3.

[0066] In one embodiment, marking the position to be drilled on the shield machine housing and sequentially installing and fixing the sealed sleeve 4, the orifice tube 3, and the hollow drill rod 1 to realize the connection of the equipment structural components includes:

[0067] S11. At the position to be drilled on the shield machine housing, use color paint to mark the center point position;

[0068] S12. Press the head flange plate 8 of the sealed sleeve 4 against the inner wall of the shield machine housing and then weld it;

[0069] S13. Connect the flange plate 8 at the tail of the orifice tube 3 to the flange plate at the tail of the sealed sleeve 4 firmly with long bolts, and tighten and fix them with nuts on both sides of the long bolts;

[0070] S14. Insert the hollow drill rod 1 into the orifice tube 3 to complete positioning, connect the rotating head to the tail of the hollow drill rod 1, and connect the external cooling water pipe 6 to the water injection hole 5.

[0071] In one embodiment, starting the core drill, injecting cooling water through the external cooling water pipe 6 to cool the toothed drill bit 2, controlling the insertion and drilling depth of the orifice tube 3, and drilling through circulation until the predetermined depth is reached, then stopping drilling and withdrawing the hollow drill rod 1 includes:

[0072] S21. Turn on the rotating head at the tail of the hollow drill pipe 1. As the hollow drill pipe 1 drills, turn on the external cooling water pipe 6 to inject cooling water. The cooling water flows back through the gap between the orifice pipe 3 and the hollow drill pipe 1 and overflows from the tail of the orifice pipe 3 into the shield machine interior.

[0073] S22. When the hollow drill pipe 1 drills to the preset starting distance, stop the machine and loosen the long bolts connecting the orifice pipe 3 and the sealing sleeve 4. Insert the orifice pipe 3 to the depth where the hollow drill pipe 1 has drilled, and cycle in turn until the hollow drill pipe 1 drills to the preset end distance at the final part of the shield machine shell.

[0074] S23. When the hollow drill pipe 1 reaches the preset end distance, close the external cooling water pipe 6. Use the coolant remaining inside the orifice pipe 3 to the hollow drill pipe 1 to continue drilling. After drilling the preset end distance, the hollow drill pipe 1 contacts the external formation and continues to drill the preset formation distance into the external formation, and use the external water and soil pressure to jack back the cut shield machine shell.

[0075] S24. When the hollow drill pipe 1 reaches the preset formation distance, stop drilling and withdraw the hollow drill pipe 1.

[0076] In one embodiment, taking out the cut shield machine shell and, after withdrawing the hollow drill pipe 1, sealing the sealing sleeve 4 and the orifice pipe 3 includes:

[0077] S31. After the hollow drill pipe 1 and the core sample are completely taken out, close the end cover plate 11 connected to the flange plate 8 at the tail of the sealing sleeve 4 and tightly fix it with bolts.

[0078] S32. Inject foaming polyurethane into the orifice pipe 3 and the sealing sleeve 4 through the polyurethane injection hole 12 at the center of the end cover plate 11.

[0079] S33. Wind the tallow packing 13 around the outside of the orifice pipe 3 in circles. After winding multiple layers, stuff it into the sealing sleeve 4 until it is full without gaps to achieve sealing.

[0080] The following introduces and explains a device for preventing block dropping during hole opening in the frozen reinforcement of the shield machine shell at the bottom of the river and its construction method provided by the present invention in combination with specific embodiments.

[0081] Such as Figure 7As shown (the bottom arc surface is the shield machine shell), before officially starting the coring construction with this device, first make the connections of the structural components. Specifically: at the position on the shield machine shell where an opening needs to be made, mark the center point with color paint. Then, closely attach the front flange 8 of the sealing sleeve 4 to the inner wall of the shield machine shell and weld it firmly. Next, firmly connect the flange 8 at the bottom of the orifice tube 3 and the flange 8 at the bottom of the sealing sleeve 4 with bolts (the length of the orifice tube 3 is greater than that of the sealing sleeve. During the docking of the flanges 8, insert long bolts successively into the bolt holes on the flanges of the sealing sleeve 4 and the orifice tube 3, and tighten and fix them with nuts on both sides). Finally, insert the core drilling rig (hollow drill pipe 1) into the orifice tube 3 to complete the positioning. The bottom of the core drilling rig is connected to a rotary head, and the side is connected to an external cooling water pipe 6.

[0082] During the official coring construction, first start the core drilling rig (hollow drill pipe 1 driven by the rotary head). As the drill advances, turn on the external cooling water pipe 6 to inject water to cool the drill bit. The sealing sleeve 4 has good sealing. The injected cooling water flows back through the gap between the orifice tube 3 and the hollow drill pipe 1 and overflows from the tail end of the orifice tube 3 into the shield machine interior. When the drill has advanced a certain distance (generally every 10 cm), stop the machine and loosen the connection bolts between the orifice tube 3 and the sealing sleeve 4, and insert the orifice tube 3 to the depth where the drill has advanced (when the drill is advancing, it is necessary to slightly expand the hole around the wall thickness of the orifice tube to ensure that the orifice tube can be inserted). Repeat this process until the drill reaches the last 3 cm of the shield shell. At this time, turn off the external cooling water pipe 6, and let the drill continue to advance relying on the cooling water remaining in the orifice tube 3 to the hollow drill pipe 1. After drilling through the last 3 cm of the shield shell, at this time the hollow drill pipe 1 is in contact with the external formation, and continue to drill 10 - 20 cm into the external formation. Use the external water and soil pressure to push the drilled shield shell back. When the drilling reaches the predetermined depth, stop drilling and withdraw the hollow drill pipe 1.

[0083] Take out the drilled shield machine shell. To prevent the connection between the external water and soil pressure and the pressure inside the shield machine, after withdrawing the hollow drill pipe 1, it is necessary to immediately seal the sealing sleeve 4 and the orifice tube 3. Specifically: the tail end flange 8 of the sealing sleeve 4 is connected to a tail end cover plate 11. After the hollow drill pipe 1 and the core sample are taken out, at this time the bolts on the flanges of the orifice tube 3 and the sealing sleeve 4 should be tightly connected. Close the tail end cover plate 11 of the sealing sleeve 4 in time and connect it tightly with bolts, and inject foaming polyurethane into the sealed orifice tube 3 and the sealing tube 4 from the polyurethane injection hole 12 at the top of the tail end cover plate 11, as Figure 8 shown.

[0084] This process occupies a small area and can be constructed simultaneously at multiple locations inside the shield machine. The specific construction process is as Figure 10 shown. Adopt the plum blossom-shaped skip-hole construction process to improve the coring speed of the shield machine shell.

[0085] The present invention not only changes the structure of the original core drilling bit, but also changes the working principle during the process of core drilling in the steel shell of the entire shield machine. Specifically, when the drill bit is 50 mm away from the completion of drilling, the external water pump of the hollow drill pipe 1 is closed, and the formation pressure is used to back-pressure water to cool the drill bit to complete the last 50 mm of drilling. After the drilling is completed, the hollow drill pipe 1 is continuously pushed 200 mm into the external formation, and the formation water and soil pressure is used to fully push the cut shield machine steel shell back into the drill pipe, preventing the shield machine steel shell from falling into the external formation.

[0086] Its implementation principle is characterized as follows:

[0087] When drilling in the shield machine shell, the most likely part where the shield machine steel shell is drilled and falls into the external formation is when drilling at the bottom of the shield machine. At this time, due to the drill rig drilling obliquely downward, the steel block slides downward under the action of its own weight and the water impact force in the drill pipe, and detaches from the drill pipe. When using this method for core drilling construction, the water pump is closed when the drilling is nearly completed, eliminating the steel shell slipping caused by the water impact on the steel shell. After the drilling is completed, the hollow drill pipe 1 is continuously pushed into the formation, and the water and soil pressure is used to balance the component force of the steel block's own weight along the drill pipe downward. In this way, the slipping of the steel shell is finally avoided.

[0088] The formula is characterized as follows:

[0089] As Figure 11 shown, according to the force analysis of the steel shell during the drilling process of the drill pipe, during the process of the hollow drill pipe 1 drilling into the shield shell, the resultant force of the cut shield shell along the drill pipe obliquely downward is:

[0090] F 合 = Gsinθ + F - μGcosθ

[0091] In the formula, G is the self-weight of the cut steel shell, F is the impact force of the drill pipe and cooling water on the steel shell, μ is the friction coefficient between the steel shell and the drill pipe, and θ is the angle between the drill pipe and the horizontal plane.

[0092] Generally speaking, the friction coefficient between steel and steel is 0.15. Then, when the drilling angle θ is 15°, the downward sliding force of the steel shell is greater than the friction force it receives, and the steel shell is prone to slipping.

[0093] After adopting this construction method, when the drill pipe is 50 mm away from the completion of drilling, the external water pump of the hollow drill pipe 1 is closed. At this time, the resultant force of the shield shell along the drill pipe obliquely downward is:

[0094] F 合 = Gsinθ - μGcosθ;

[0095] At this time, in the ideal state, the shield shell is only affected by its own weight and friction force.

[0096] As Figure 9As shown in the figure (the upper layer is water and the lower layer is soil), the force analysis of the steel shell during the drilling process of the improved drill rod of the present invention is that after the hollow drill rod 1 is drilled, the hollow drill rod 1 is further pushed into the external stratum by 200 mm. At this time, the resultant force on the shield shell is:

[0097] F 合 =Gsinθ-μGcosθ-M;

[0098] Where M is the external water-soil force, and the Rankine active earth pressure formula is used, which is:

[0099]

[0100] Where γ is the weight of the external soil, Z is the height difference between the ground and the center of the borehole, and K a is the active earth pressure coefficient, and C is the cohesion. in is the internal friction angle.

[0101] By F 合 =Gsinθ-μGcosθ-M It can be seen from the formula that when the water pump is turned off, the friction coefficient μ increases. At the same time, because the external water and soil force is added, the component force of the drilled steel shell along the hollow drill rod 1 is much smaller than the component force before no measures are taken. In this case, the drilled steel shell is less likely to slide off the drill rod.

[0102] In summary, by means of the above technical scheme of the present invention, by adding a bayonet in the orifice pipe 3, during the drilling of the shield machine shell, the drilled shield machine shell is prevented from falling into the external stratum and blocking the drilling of the later drill bit; at the same time, after the drilling length reaches the thickness of the shield shell, the hollow drill rod 1 continues to drill into the stratum for 20cm and then stops drilling, and the drilled shield machine shell is pushed back to the inside of the shield machine through the external water and soil pressure, so as to achieve the purpose of taking out the shield shell and preventing it from falling into the external stratum and affecting the subsequent freezing pipe drilling. The present invention is simple and convenient to operate, and only needs to set a bayonet in the drilling rig to clamp the drilled shield shell and stop for 5 to 10 seconds after completing the drilling, and then lift the drilling rig; and the scope of application is wide, not only suitable for opening holes in shield machines, but also suitable for opening holes in other underground structures to prevent falling construction; in addition, the present invention has good use effect, because the part of the existing drilling rig that is modified is small, it will not affect the use of the drilling rig; at the same time, the design of adding a bayonet and the improved construction process can ensure that the shield machine steel shell is completely taken out.

[0103] The key improvement part of the present invention lies in the transformation inside the orifice pipe 3. Three hoop rings 7 are welded inside the orifice pipe 3. The hoop rings 7 are made of Q355B steel and are formed into hoops and then welded to the inner wall of the orifice pipe 3. After welding, the inner diameter of the hoop ring 7 is consistent with the outer diameter of the hollow drill pipe 1. After adding this hoop ring device, it mainly plays two roles: ① When the drill rig drives the hollow drill pipe 1 to drill and take cores in the steel shell of the shield machine, a large degree of irregular vibration will occur. These irregular vibrations are likely to cause the hollow drill pipe 1 to deviate during the drilling process. After adding the hoop ring 7, it constrains the hollow drill pipe 1 so that it can always maintain the set route during the drilling process. ② During the process of the hollow drill pipe 1 drilling through the shield shell to take cores, the removed shield shell will push back under the action of the external water and soil pressure. At this time, when the hollow drill pipe 1 retracts, it will carry external sediment, resulting in the deviation and slipping of the taken core sample into the external formation, and the core sampling fails. By adding three hoop rings 7 inside the orifice pipe 3, since the inner diameter of the hoop ring 7 is basically the same as the outer diameter of the core sample, even if the core sample deviates inside the core sampling pipe, it will still be blocked by the hoop ring 7 and will not slip into the external formation.

[0104] It should be understood that although the steps in the flowchart of the accompanying drawings are shown sequentially according to the indication of the arrows, these steps are not necessarily executed sequentially according to the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit and can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed alternately or alternately with at least a part of the sub-steps or stages of other steps or other steps.

Claims

1. An equipment for preventing falling blocks of the opening in the frozen reinforced casing of a shield machine at the bottom of a river, characterized in that, The equipment includes a hollow drill pipe (1), and a toothed drill bit (2) is arranged at the head of the hollow drill pipe (1); In order to achieve the pipe stabilization and core sampling of the hollow drill pipe (1), a hole opening pipe (3) is sleeved on the outer circumference of the hollow drill pipe (1), and a sealing sleeve (4) is sleeved on the outer circumference of the hole opening pipe (3) to ensure the tightness of the drilling process and prevent the shield machine from losing pressure due to connection with the outside; A water injection hole (5) is opened at the tail of the hollow drill pipe (1), and an external cooling water pipe (6) is arranged inside the water injection hole (5) to inject cooling water to cool the toothed drill bit (2).

2. The anti-falling block equipment for opening holes in the casing of the freezing reinforcement of the river-bottom shield machine according to claim 1, characterized in that The length of the hole opening pipe (3) is less than the length of the hollow drill pipe (1), and the length of the hole opening pipe (3) is greater than the length of the sealing sleeve (4); A plurality of hoop rings (7) are welded inside the hole opening pipe (3). The material of the hoop rings (7) is the same as that of the hole opening pipe (3), and the inner diameter of the hoop rings (7) is the same as the outer diameter of the hollow drill pipe (1) to ensure the insertion fit between the hollow drill pipe (1) and the hoop rings (7).

3. A kind of equipment for preventing falling blocks at the opening in the frozen reinforced casing of a river-bottom shield machine according to claim 1, characterized in that, The toothed drill bit (2) is made of 10 alloy teeth and is used to rotate and cut the steel shell of the shield machine driven by the rotating head at the tail of the hollow drill pipe (1).

4. A kind of equipment for preventing falling blocks at the opening in the frozen reinforced casing of a river-bottom shield machine according to claim 1, characterized in that, Flange plates (8) are arranged at both ends of the tail of the hole opening pipe (3) and the sealing sleeve (4); The flange plate (8) at the head of the sealing sleeve (4) is fixed to the inner wall of the shield machine shell by welding for positioning the core sampling position; A plurality of equally spaced connecting bolt holes (9) are opened on the circumferential outer edge of the flange plate (8) at the tail of the sealing sleeve (4), and the connecting bolt holes (9) and the flange plate (8) at the tail of the hole opening pipe (3) are connected by long bolts.

5. A device for preventing block falling from the opening in the frozen reinforcement of the casing of a subaqueous shield machine according to claim 4, characterized in that, One side of the flange plate (8) at the tail of the sealing sleeve (4) is connected with a tail end cover plate (11) through a connecting lock (10). A polyurethane injection hole (12) is opened at the center of the tail end cover plate (11). After the core is taken out, the tail end cover plate (11) is covered, and polyurethane is injected through the polyurethane injection hole (12) to prevent the pressure connection between the inside and outside of the shield machine.

6. A kind of equipment for preventing falling blocks at the opening in the frozen reinforced casing of a river-bottom shield machine according to claim 5, characterized in that, After the tail end cover plate (11) is covered, a grease packing (13) is wound around the outside of the hole opening pipe (3) to achieve the sealing inside the sealing sleeve (4).

7. A construction method for preventing block falling from the opening in the frozen reinforcement casing of a river-bottom shield machine, which is used to implement the construction of the equipment for preventing block falling from the opening in the frozen reinforcement casing of a river-bottom shield machine described in claims 1-6, is characterized in that, This construction method includes: S1. Mark the part to be drilled on the shield machine shell, and sequentially install and fix the sealing sleeve (4), the hole opening pipe (3) and the hollow drill pipe (1) to realize the connection of the equipment structural parts; S2. Start the core sampling drill, inject cooling water by using the external cooling water pipe (6) to cool the toothed drill bit (2), control the insertion and drilling depth of the hole opening pipe (3), and drill through circulation until the predetermined depth is reached. Stop drilling and withdraw the hollow drill pipe (1); S3. Take out the drilled shield machine shell, and after withdrawing the hollow drill pipe (1), seal the sealing sleeve (4) and the hole opening pipe (3).

8. A construction method for preventing block dropping from the opening in the casing of the freezing reinforcement of the river-bottom shield machine according to claim 7, characterized in that Mark the position to be drilled on the shield machine shell, and install and fix the sealing sleeve (4), orifice tube (3) and hollow drill pipe (1) in sequence. The connection of the equipment structural parts includes: S11. At the position to be drilled on the shield machine shell, mark the center point position with color paint; S12. Weld the head flange (8) of the sealing sleeve (4) tightly against the inner wall of the shield machine shell; S13. Connect the flange (8) at the tail of the orifice tube (3) to the flange at the tail of the sealing sleeve (4) firmly with long bolts, and tighten and fix with nuts on both sides of the long bolts; S14. Insert the hollow drill pipe (1) into the orifice tube (3) to complete the positioning, connect the rotating head to the tail of the hollow drill pipe (1), and connect the external cooling water pipe (6) to the water injection hole (5).

9. A construction method for preventing block falling from the opening in the casing of the freezing reinforcement of a river-bottom shield machine according to claim 7, characterized in that Start the core drill, inject cooling water through the external cooling water pipe (6) to cool the toothed drill bit (2), control the insertion and drilling depth of the orifice tube (3), and drill through circulation until the predetermined depth is reached. Stop drilling and withdraw the hollow drill pipe (1), including: S21. Start the rotating head at the tail of the hollow drill pipe (1). As the hollow drill pipe (1) drills, start injecting cooling water through the external cooling water pipe (6). The cooling water flows back through the gap between the orifice tube (3) and the hollow drill pipe (1) and overflows from the tail of the orifice tube (3) into the shield machine interior; S22. When the hollow drill pipe (1) drills a preset starting distance, stop the machine and loosen the long bolts connecting the orifice tube (3) and the sealing sleeve (4), insert the orifice tube (3) to the depth drilled by the hollow drill pipe (1), and cycle in sequence until the hollow drill pipe (1) drills to the last preset end distance of the shield machine shell; S23. When the hollow drill pipe (1) reaches the preset end distance, close the external cooling water pipe (6), and continue drilling using the coolant remaining inside the orifice tube (3) to the hollow drill pipe (1). When the preset end distance is drilled, the hollow drill pipe (1) contacts the external formation, continues to drill into the external formation for a preset formation distance, and uses the external water and soil pressure to jack back the drilled shield machine shell; S24. When the hollow drill pipe (1) reaches the preset formation distance, stop drilling and withdraw the hollow drill pipe (1).

10. A construction method for preventing block falling from the opening in the frozen reinforcement casing of a river-bottom shield machine according to claim 7, characterized in that Take out the drilled shield machine shell, and after withdrawing the hollow drill pipe (1), seal the sealing sleeve (4) and the orifice tube (3), including: S31. After the hollow drill pipe (1) and the core sample are completely taken out, close the end cover plate (11) connected to the tail flange (8) of the sealing sleeve (4), and fix it tightly with bolts; S32. Inject foaming polyurethane into the orifice tube (3) and the sealing sleeve (4) through the polyurethane injection hole (12) at the center of the end cover plate (11); S33. Wind the tallow packing (13) around the outside of the orifice tube (3) in circles, and after winding multiple layers, stuff it into the sealing sleeve (4) until it is full without gaps to achieve sealing.

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