A tool for controlling ground deformation during pipe jacking back-off and re-jacking

Abstract

The utility model provides a kind of tool for controlling surface deformation in the process of pipe jacking back and re-jacking.The tool for controlling surface deformation in the process of pipe jacking back and re-jacking includes: pipe section, counterforce frame and bag set on the well wall of working well;the pipe section is connected with the well wall of working well through counterforce frame;the pipe section is provided with pipe jacking machine, backfill material and jack;the bag includes two states, and the two states are respectively uninflated bag and inflated bag;sleeve, the sleeve is arranged at the front end of bag.The tool for controlling surface deformation in the process of pipe jacking back and re-jacking provided by the utility model expands by inflating the bag, reduces the stratum loss of soil body caused by back construction, and reduces the influence on surrounding environment;the bag is simple to make, easy to inflate, and low in cost, which provides the advantages of convenience for pipe jacking back and re-jacking construction.

Description

Technical Field

[0001] This utility model belongs to the field of underground pipe jacking construction technology, and in particular relates to a tool for controlling surface deformation during pipe jacking retreat and re-jacking. Background Technology

[0002] Pipe jacking technology is increasingly widely used due to its advantages such as high construction precision, fast tunneling speed, minimal ground disturbance, high construction safety, and low overall cost, especially in construction projects involving busy roads or underpasses of buildings and structures. If encountering underground boulders during pipe jacking makes further jacking impossible, a pipe retreat strategy can be adopted. After retreating, modifying or replacing the pipe jacking machine and then performing a secondary jacking is also a feasible solution. For example, in the Wuhan Tangxun Lake Wastewater Treatment Plant tailwater discharge pipe jacking project, reinforced concrete blocks approximately 300 mm in size and pebbles exceeding 200 mm in size were encountered during the jacking process of the pipe jacking machine cutterhead. Because the initial selection of the pipe jacking machine did not adequately consider measures for handling large-diameter reinforced concrete blocks and boulders, the already jacked pipe sections and equipment had to be withdrawn from the tunnel. The construction was completed by modifying and replacing the pipe jacking machine and then performing a secondary jacking.

[0003] During the pipe jacking retreat process, to ensure the stability of the strata, backfill material is simultaneously injected into the cavity in front of the jacking head during the overall pipe retreat. After each pipe section is retreated, a pause is required (generally 4-6 hours) to allow the backfill material to initially set before continuing to retreat the next section. During the initial jacking, retreat, and re-jacking operations, the surrounding soil is repeatedly disturbed. Significant deformation can damage surrounding buildings, structures, and roads. Furthermore, the solidification of the backfill material during retreat will cause some volume shrinkage, inevitably inducing some soil settlement. Figure 1 As shown.

[0004] Therefore, how to reduce the deformation of the backfill material in the backfill cavity during the pipe jacking retreat construction, while also considering the convenience of subsequent re-jacking construction, is a technical issue worthy of study.

[0005] Therefore, it is necessary to provide a new tool to control surface deformation during the pipe jacking retreat and re-jacking process to solve the above-mentioned technical problems. Utility Model Content

[0006] The technical problem solved by this utility model is to provide a tool that expands and enlarges the volume of the pipe jacking bag by inflation, thereby reducing the loss of soil layers during the retreat construction and reducing the impact of the retreat construction on the surrounding environment. The bag is simple to make, easy to inflate, and inexpensive, providing a convenient tool for controlling the surface deformation during the pipe jacking retreat and re-jacking construction.

[0007] To solve the above-mentioned technical problems, the tool provided by this utility model for controlling surface deformation during pipe jacking retreat and re-jacking includes: a pipe section, a reaction frame, and a bladder bag installed on the working shaft wall; the pipe section is connected to the working shaft wall through the reaction frame; the pipe section is equipped with a pipe jacking machine, backfill material, and jacks; the bladder bag has two states, namely an uninflated bladder bag and an inflated bladder bag; a casing is installed at the front end of the bladder bag; an inflation pipe is connected to the rear end of the bladder bag, and the tail end of the inflation pipe is equipped with not less than two valves; the uninflated bladder bag can be inserted into the casing through a slender rod, and the bladder bag is squeezed into the backfill material in front of the pipe jacking machine based on the slender rod; the bladder bag is squeezed into the backfill material and inflated to the rated pressure based on the inflation pipe, and an inflated bladder bag is formed by closing all valves; the working shaft wall is sealed with steel sheet piles.

[0008] As a further embodiment of this utility model, both the bladder and the inflation tube are made of elastic rubber material, and the hollow inner diameter of the inflation tube is no greater than 1.0 cm.

[0009] As a further embodiment of this utility model, the pipe jacking machine is equipped with a pipe pull cable inside.

[0010] Compared with related technologies, the tool provided by this utility model for controlling surface deformation during pipe jacking retraction and re-jacking has the following beneficial effects: 1. The bag of this utility model is located in the backfill material during the pipe jacking retreat construction. By inflating and expanding its volume, it reduces the soil loss caused by the retreat construction, reduces the impact of the retreat construction on the surrounding environment, and improves the safety and reliability of the retreat construction. 2. The bag provided by this utility model is simple to make, easy to inflate, and inexpensive. The inflation operation time is approximately the length of one pipe section between the bag and the pipe jacking machine and before the retreat construction is restarted. It will not cause any squeezing effect on the retreat construction working surface. 3. The bag in this utility model is filled with high-pressure air, which has no impact on the jacking construction during the re-jacking construction, thus providing convenience for the pipe jacking retreat and re-jacking construction. Attached Figure Description

[0011] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0012] Figure 1 Schematic diagram of soil settlement induced by jacking and pulling back construction; Figure 2 This is a schematic diagram of the uninflated airbag of this utility model; Figure 3 A schematic diagram showing the insertion of a thin rod into the backfill material when the air-filled bag is not inflated during construction. Figure 4This is a schematic diagram of the inflated bag of this utility model; Figure 5 A schematic diagram showing the preparation for retreat when the jacking operation is stopped; Figure 6 A schematic diagram showing the length of one pipe section retracted during the jacking and retraction construction. Figure 7 A schematic diagram showing the length of the two pipe sections retracted during the jacking and retraction construction; Figure 8 A schematic diagram showing the length of the three pipe sections retracted during the jacking and retraction construction; Figure 9 A schematic diagram illustrating the sequential retraction of each pipe section during the jacking and retraction construction; Figure 10 This is a diagram illustrating the completion of the rollback construction.

[0013] In the diagram: 1. Working shaft wall; 2. Pipe section; 3. Pipe jacking machine; 4. Backfill material; 5. Reaction frame; 6. Jack; 7. Surface settlement curve; 8. Uninflated airbag; 9. Casing; 10. Inflatable pipe; 11. Valve; 12. Slender rod; 13. Inflatable airbag; 14. Sheet pile closure. Detailed Implementation

[0014] Please refer to the following: Figure 1 , Figure 2 and Figure 3 ,in, Figure 1 Schematic diagram of soil settlement induced by jacking and pulling back construction; Figure 2 This is a schematic diagram of the uninflated airbag of this utility model; Figure 3 This diagram illustrates the insertion of a thin rod into the backfill material when the air-filled bag is not inflated during construction. The tools for controlling surface deformation during pipe jacking retreat and re-jacking include: a pipe section 2, a reaction frame 5, and a bladder bag installed on the working shaft wall 1; the pipe section 2 is connected to the working shaft wall 1 via the reaction frame 5; the pipe section 2 is equipped with a pipe jacking machine 3, backfill material 4, and jacks 6; the bladder bag has two states, namely an uninflated bladder bag 8 and an inflated bladder bag 13; a casing 9 is installed at the front end of the bladder bag; an inflation pipe 10 is connected to the rear end of the bladder bag, and the tail end of the inflation pipe 10 is equipped with at least two valves 11; the uninflated bladder bag 8 can be inserted into the casing 9 via a slender rod 12, and the bladder bag is squeezed into the backfill material 4 in front of the pipe jacking machine 3 based on the slender rod 12; the bladder bag is squeezed into the backfill material 4 and inflated to the rated pressure based on the inflation pipe 10, and the inflated bladder bag 13 is formed by closing all valves 11; the working shaft wall 1 is equipped with a steel sheet pile enclosure 14.

[0015] The inflatable bladder 13 is located above the original pipe section. One bladder is set in the backfill 4 at the original pipe section position, and each bladder is independent and does not affect the others.

[0016] The pouch has a sleeve 9 at the front end and an inflation tube 10 at the rear end. The inflation tube 10 has at least two valves 11 at its tail end. Figure 2 As shown, the "front end" refers to the end that is at the very beginning of the process of squeezing the bag into the backfill material, and the "rear end" refers to the tail end of the process of squeezing the bag into the backfill material. The function of valve 11 is to close all valves 11 after the bag is inflated to the rated pressure, which ensures the airtightness of the bag and prevents air leakage. The presence of at least two valves 11 is to improve the reliability of the airtightness of the inflated bag and ensure that no air leakage occurs after the bag is inflated. Since the diameter of the inflation pipe 10 is small, at least two valves 11 are provided, which has no essential impact on the cost.

[0017] When the bladder bag is not inflated, a slender rod 12 is inserted into the sleeve 9. The slender rod 12 can push the bladder bag 8 into the backfill material 4 in front of the pipe jacking machine 3. Figure 3 As shown, the function of the sleeve 9 is to serve as the fixed support point and force application point of the slender rod 12 when the bag 8 is squeezed into the backfill 4. The sleeve 9 should have sufficient strength to ensure that the bag 8 is not damaged or fails during the process of the slender rod 12 pressing the bag into the backfill 4. Otherwise, the bag 8 cannot be pressed into the backfill 4 to the specified horizontal distance based on the slender rod 12. When the slender rod 12 is pulled out, the bag 8 that has been squeezed into the backfill 4 will not be taken out.

[0018] After the bag 8 is filled with the backfill material 4, it is inflated into the bag through the inflation pipe 10 until it reaches the rated pressure. Then, all valves 11 are closed, and the bag 13 is in a sealed state with no internal air leakage. The inflated bag 13, as... Figure 4 As shown, the air pressure inside the bag should be determined comprehensively based on geological conditions, burial depth, etc., and is generally slightly greater than the grouting pressure when the backfill material 4 is filled. Usually, the grouting pressure of the backfill material 4 is about 0.2MPa. At this time, the air pressure inside the bag can be 0.25 to 0.3MPa. The bag should have sufficient elasticity and strength, and should not be damaged under the inflation of the specified air pressure value, and should have sufficient safety reserve.

[0019] During the typical retreat construction process, after a standard pipe section is pushed back into the working shaft, the retreat operation is paused, the pipe section is lifted out of the working shaft, and then the next retreat operation is carried out. That is, when each pipe section is retreated and the cavity in front of the pipe jacking machine is filled with backfill material 4, the retreat operation needs to be paused for a period of time. At this time, an air bag can be squeezed into the backfill material 4 at the original pipe section position. The air bag is located above the original pipe section position. One air bag is set in the backfill material 4 at the original pipe section position, and each air bag is independent of each other and does not affect each other.

[0020] The aforementioned bladder and inflation tube 10 are both made of elastic rubber material. The hollow inner diameter of the inflation tube 10 is no more than 1.0 cm. Air is injected into the bladder using an air compressor based on the inflation tube 10. The diameter of the inflation tube 10 does not need to be too large, as a large diameter will affect the subsequent sealing of the bladder. The inflation tube 10 should have sufficient length to facilitate subsequent inflation within the cavity of the jacking machine 3.

[0021] The operation time for squeezing the bag into the backfill 4 based on the slender rod 12 is when the retraction length reaches the length of one pipe section 2, the cavity in front of the pipe jacking machine 3 is filled with the backfill 4 and before the backfill 4 initially sets. After the backfill 4 initially sets, its strength gradually increases, making it obviously more difficult to squeeze into the bag.

[0022] The inflation time of the bladder in the extruded backfill 4 is when the distance between the bladder and the pipe jacking machine 3 is approximately the length of one pipe section 2 and before the retreat construction is restarted. At this time, the additional pressure generated by the expansion of the bladder's inflation volume has virtually no impact on the working face of the pipe jacking machine 3. The distance between the inflated bladder and the working face of the pipe jacking machine 3 is one pipe section length, so the squeezing effect on the retreat construction working face is weak.

[0023] Both the bladder and the inflation tube 10 are made of elastic rubber material, and the hollow inner diameter of the inflation tube is no more than 1.0 cm.

[0024] The operation time for the slender rod 12 to squeeze the bag into the backfill 4 is when the retraction length reaches the length of one pipe section 2, the cavity in front of the pipe jacking machine 3 is filled with the backfill 4, and before the backfill 4 initially sets.

[0025] The inflation operation time for the bag to be squeezed into the backfill 4 is when the distance between the bag and the pipe jacking machine 3 is approximately the length of one pipe section 2 and before the retreat construction is restarted.

[0026] The pipe jacking machine 3 is equipped with a pipe pull cable inside.

[0027] The method of using a tool for controlling surface deformation during pipe jacking retraction and re-jacking is as follows: (1) When it is determined that the pipe jacking construction needs to be reversed, based on the installation of pipe jacking cable inside the pipe jacking machine 3, the installation of reaction frame and jacks inside the working shaft, and the segmented loosening of the pipe, preparations are made for the formal reverse construction, such as Figure 5 As shown; (2) Formal pipe retraction, controlling the retraction rate, and simultaneously pumping backfill 4 into the cavity in front of the pipe jacking machine 3. After the first pipe section is jacked back into the working well, the retraction operation is paused, and the pipe section 3 is lifted out of the working well. At this time, the first inflatable bag can be squeezed into the backfill 4 in front of the pipe jacking machine 3 based on the slender rod 12. The inflatable bag is squeezed into the backfill 4 at the original position of the pipe section, and the inflatable bag is located above the original position of the pipe section, such as... Figure 6As shown, the operation time for squeezing the bag into the backfill 4 based on the slender rod 12 is when the retraction length reaches the length of one pipe section 2, the cavity in front of the pipe jacking machine 3 is filled with the backfill 4, and before the backfill 4 initially sets. (3) Continue the retreat construction. After the second pipe section is pushed back into the working well, the retreat operation is suspended. The pipe section 3 is lifted out of the working well. During this period, the second bag is squeezed into the backfill 4 in front of the pipe jacking machine 3 based on the slender rod 12. (4) Before the retraction construction of the third pipe section begins, use an air compressor to inject air into the first bladder via the inflation pipe 10. After the bladder is inflated to the rated pressure, close all valves 11. Figure 7 As shown, the retreat operation is carried out again. After the third pipe section is pushed back into the working well, the retreat operation is suspended and the pipe section 3 is lifted out of the working well. During this period, the third bag is squeezed into the backfill 4 in front of the pipe jacking machine 3 based on the slender rod 12. (5) Before the retraction construction of the fourth pipe section begins, use an air compressor to inject air into the second bladder via the inflation pipe 10. After the bladder is inflated to the rated pressure, close all valves 11. Figure 8 As shown, the retraction work is then carried out, repeating the above steps alternately, retracting and hoisting out each pipe section in turn until the retraction of all pipe sections is completed, as shown. Figure 9 and Figure 10 As shown The beneficial effects of this utility model are as follows: the lifting bag is located in the backfill material during the pipe jacking retreat construction. By inflating and expanding its volume, it reduces the soil loss caused by the retreat construction, reduces the impact of the retreat construction on the surrounding environment, and improves the safety and reliability of the retreat construction. The lifting bag is simple to manufacture, easy to inflate, and inexpensive. The inflation operation time is approximately the length of one pipe section between the bag and the pipe jacking machine and before the retreat construction is restarted, so it will not have a squeezing effect on the retreat construction working face. The lifting bag is filled with high-pressure air, which has no impact on the jacking construction when the jacking is restarted, thus providing convenience for pipe jacking retreat and re-jacking construction.

[0028] It should be noted that the device structure and accompanying drawings of this utility model mainly describe the principle of this utility model. In terms of the technical aspects of this design principle, the setting of the power mechanism, power supply system and control system of the device is not fully described. However, under the premise that those skilled in the art understand the principle of the above utility model, the specific details of its power mechanism, power supply system and control system can be clearly understood. The control method in the application document is automatic control through a controller. The control circuit of the controller can be implemented by those skilled in the art through simple programming. All standard parts used can be purchased from the market, and can be customized according to the instructions and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the existing technology. The machinery, parts and equipment adopt conventional models in the existing technology, and the structure and principle of the components known to those skilled in the art can be known by those skilled in the art through technical manuals or conventional experimental methods.

[0029] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and alterations can be made to these embodiments, or they can be used directly or indirectly, without departing from the principles and spirit of the present invention. In other related technical fields, the scope of the present invention is defined by the appended claims and their equivalents, and they are similarly included within the patent protection scope of the present invention.

Claims

1. A tool for controlling surface deformation during pipe jacking retraction and re-jacking, characterized in that, include: Pipe sections, reaction frames, and bladders installed on the walls of the working shaft; The pipe section is connected to the working well wall via a reaction frame; The pipe section is equipped with a pipe jacking machine, backfill material, and jacks; The bag includes two states: an uninflated bag and an inflated bag. A cannula, wherein the cannula is disposed at the front end of the sac; An inflation tube is connected to the rear end of the bladder, and the tail end of the inflation tube is provided with not less than two valves. The uninflated bag can be inserted into the sleeve by a thin rod, and the bag can be squeezed into the backfill material in front of the pipe jacking machine based on the thin rod; The bag is squeezed into the backfill material and inflated to the rated pressure by inflating the bag through the inflation tube, and an inflatable bag is formed by closing all valves; The working well wall is sealed with steel sheet piles.

2. The tool for controlling surface deformation during pipe jacking retraction and re-jacking as described in claim 1, characterized in that: Both the bladder and the inflation tube are made of elastic rubber material, and the hollow inner diameter of the inflation tube is no more than 1.0 cm.

3. The tool for controlling surface deformation during pipe jacking retraction and re-jacking as described in claim 1, characterized in that: The pipe jacking machine is equipped with a pipe pull cable inside.

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