A pipe joint system and construction method for top shield construction in water-rich hard rock formations

Abstract

The present application provides a pipe segment system and construction method for top shield construction in water-rich hard rock formations, and belongs to the technical field of top shield construction. The present application sets a wire brush on the outer wall of the first pipe segment, and the two wire brushes, the outer wall of the pipe segment and the formation soil form a closed chamber, and the closed chamber is filled with high-viscosity mud. The closed space can avoid leakage of high-viscosity mud; during the jacking process, the wire brush can carry the high-viscosity mud and move synchronously, so that the outer wall of the first pipe segment is always covered with high-viscosity mud, avoiding groundwater scouring and diluting the drag-reducing mud, and reducing the resistance of jacking.

Description

Technical Field

[0001] The present application belongs to the technical field of top shield construction, and specifically relates to a pipe joint system and a construction method for top shield construction in water-rich hard rock formations. Background Art

[0002] The shield machine construction method combines the advantages of pipe jacking and shield methods, and is widely used in the construction of underground pipe networks such as urban electricity and gas, providing a new solution for the utilization of urban underground space. During long-distance pipe jacking construction, the jacking resistance of the shield machine will increase with the increase of distance. In order to ensure the efficiency of pipe jacking construction, the resistance to the shield can be effectively reduced by injecting drag-reducing mud between the outer wall of the pipe segment and the soil of the formation to form a mud sleeve.

[0003] However, when constructing in water-rich hard rock formations, the mud will be diluted and carried away due to the scouring effect of fissure water, and an effective mud sleeve will not be formed, thereby reducing the drag reduction performance of the mud; and, during the construction process, as the jacking distance increases, the first pipe segment continues to move forward, while the friction between the first pipe segment and the drag reduction mud is small. The first pipe segment cannot carry the drag reduction mud on the outer wall of the pipe segment and move forward synchronously, so that the first pipe segment is in direct contact with the stratum soil in front during the jacking process, and a large jacking resistance needs to be overcome.

[0004] Therefore, it is necessary to provide a pipe joint system and a construction method for top shield construction in water-rich hard rock formations to solve the problems raised in the above background technology. Summary of the invention

[0005] The present application provides a pipe segment system and a construction method for top shield construction in water-rich hard rock formations. A wire brush is arranged on the outer wall of the first pipe segment. The two wire brushes, the outer wall of the pipe segment and the formation soil cooperate to form a closed chamber. The closed chamber is filled with high-viscosity mud. The closed space can prevent leakage of the high-viscosity mud. During the jacking process, the wire brush can carry the high-viscosity mud and move synchronously, so that the outer wall of the first pipe segment is always covered with the high-viscosity mud, avoiding direct contact with the formation soil, and reducing the resistance to jacking.

[0006] In order to solve the above technical problems, the technical solution of this application is:

[0007] A pipe segment system for top shield construction in water-rich hard rock formations comprises a plurality of pipe segments connected in sequence along a jacking direction, wherein the plurality of pipe segments are divided into high-viscosity mud pipe segments and ordinary mud pipe segments, wherein the high-viscosity mud pipe segment comprises at least a leading pipe segment located at the frontmost of the plurality of pipe segments along the jacking direction, and wire brushes are installed at both the front and rear ends of the high-viscosity mud pipe segment, wherein the wire brush surrounds the outer wall of the high-viscosity mud pipe segment, one end of the wire brush is fixed to the outer wall of the high-viscosity mud pipe segment, and the other end of the wire brush extends toward and abuts against the formation soil, wherein the two wire brushes, the outer wall of the high-viscosity mud pipe segment and the formation soil form a closed chamber filled with high-viscosity mud; and the outer wall of the ordinary mud pipe segment and the formation soil form an open chamber filled with ordinary mud.

[0008] As a preferred improvement, the high-viscosity mud pipe segment only includes a leading pipe segment located at the front of the plurality of pipe segments along the jacking direction.

[0009] As a preferred improvement, the high-viscosity mud pipe segment includes a first pipe segment located at the front of the plurality of pipe segments along the jacking direction and at least one other pipe segment other than the first pipe segment.

[0010] As a preferred improvement, the wire brush includes a steel casing and steel bristles, the steel casing includes a fixed portion fixed to the outer wall of the high-viscosity mud pipe section and an extension portion extending obliquely from one end of the fixed portion toward a direction close to the stratum soil, the extension portion and the fixed portion cooperate to form a receiving space with an opening at one end, the opening of the receiving space faces the stratum soil, the open end of the steel casing is spaced apart from the stratum soil to form a gap, one end of the steel bristles is fixed to the fixed portion, and the other end passes through the gap and abuts against the stratum soil.

[0011] As a preferred improvement, the receiving space includes a subspace located within the extension portion, the cross-sectional area of ​​the subspace gradually increases toward the direction approaching the stratum soil, and the steel bristles are assembled from a plurality of steel wires, each of which passes through one end of the slit and is freely scattered.

[0012] As a preferred improvement, along the pushing direction of the pipe section, the fixing portion is located in front of the extending portion, and the angle between the extending portion and the fixing portion is an obtuse angle, and the shape of the steel bristles matches the shape of the steel casing.

[0013] As a preferred improvement, the high-viscosity mud pipe section is provided with four grouting holes evenly arranged along the annular direction, and a reflux hole is provided between any two adjacent grouting holes, the grouting holes and the reflux hole are both connected to the closed chamber, the grouting holes are used to inject high-viscosity mud into the closed chamber, and the reflux hole is used to extract the high-viscosity mud in the closed chamber.

[0014] As a preferred improvement, the grouting pressure of the high-viscosity mud is higher than the external water pressure, and the grouting pipelines used in the four grouting holes are connected in series in sequence.

[0015] As a preferred improvement, the high-viscosity mud and the ordinary mud are both prepared from bentonite and water, wherein the amount of bentonite in the high-viscosity mud is higher than that in the ordinary mud, and the high-viscosity mud and the ordinary mud are grouting using independent grouting pipelines.

[0016] A construction method for top shield construction in water-rich hard rock formations, comprising the following steps:

[0017] Step S1, providing the above-mentioned pipe joint system for top shield construction in water-rich hard rock formations;

[0018] Step S2, providing a grouting pipeline for high-viscosity mud, and injecting high-viscosity mud into the closed chamber; providing a grouting pipeline for ordinary mud, and injecting ordinary mud into the open chamber;

[0019] Step S3, driving the pipe segment to advance, and the high-viscosity mud pipe segment carries the high-viscosity mud in the closed chamber and moves synchronously along the advancement direction;

[0020] Step S4, detecting the viscosity of the high-viscosity mud in the closed chamber, and if the viscosity is lower than a threshold, replacing the high-viscosity mud in the closed chamber.

[0021] The beneficial effects of this application are:

[0022] By arranging a wire brush on the outer wall of the first pipe section, the two wire brushes, the outer wall of the pipe section and the stratum soil cooperate to form a closed chamber, and the closed chamber is filled with high-viscosity mud. The closed space can effectively prevent loss under the action of fissure water scouring. After the high-viscosity mud is diluted by the fissure water, it can be directly replaced;

[0023] During the jacking process, the wire brush can carry the high-viscosity mud and move synchronously, so that the outer wall of the high-viscosity mud pipe section is always covered with the high-viscosity mud, avoiding direct contact with the formation soil, and reducing the jacking resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A structural schematic diagram showing a pipe segment system for top shield construction in water-rich hard rock formations provided by the present application;

[0025] Figure 2 Another structural schematic diagram showing a pipe segment system for top shield construction in water-rich hard rock formations provided by the present application;

[0026] Figure 3 A schematic diagram showing the installation of a wire brush on a high viscosity mud pipe section;

[0027] Figure 4 An enlarged view showing the gap between the steel casing and the ground soil;

[0028] Figure 5 Schematic diagram of the grouting pipeline showing the high viscosity mud pipe segment. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] Please refer to Figure 1-Figure 5 This embodiment provides a pipe segment system for top shield construction in water-rich hard rock formations, including a plurality of pipe segments 10 sequentially connected along a jacking direction, wherein the plurality of pipe segments 10 are divided into high-viscosity mud pipe segments 11 and ordinary mud pipe segments 12.

[0031] like Figure 1 As shown, in this embodiment, the high viscosity mud pipe segment 11 only includes the first pipe segment located at the front of the plurality of pipe segments 10 along the jacking direction. Figure 2 As shown, in other embodiments, the high-viscosity mud pipe segment 11 may include other pipe segments besides the first pipe segment.

[0032] Wire brushes 20 are installed at both the front and rear ends of the high-viscosity mud pipe segment 11. The wire brush 20 surrounds the outer wall of the high-viscosity mud pipe segment 11, one end is fixed to the outer wall of the high-viscosity mud pipe segment 11, and the other end extends toward the formation soil 100 and abuts against the formation soil 100. The two wire brushes 20, the outer wall of the high-viscosity mud pipe segment 11 and the formation soil 100 cooperate to form a closed chamber 30, and the closed chamber 30 is filled with high-viscosity mud 31; the outer wall of the ordinary mud pipe segment 12 cooperates with the formation soil 100 to form an open chamber 40, and the open chamber 40 is filled with ordinary mud 41.

[0033] The arrangement of the wire brush 20 makes the closed chamber 30 and the open chamber 40 independent of each other, thereby preventing the ordinary mud 41 from mixing with the high-viscosity mud 31 and causing dilution of the high-viscosity mud 31. Preferably, the high-viscosity mud 31 and the ordinary mud 41 are grouting in independent grouting pipelines.

[0034] As the high-viscosity mud pipe segment 11 is pushed forward, the closed chamber 30 moves forward synchronously, and the high-viscosity mud 31 in the closed chamber 30 also moves forward. The outer wall of the high-viscosity mud pipe segment 11 always forms a mud sleeve, which can effectively reduce the resistance encountered by the high-viscosity mud pipe segment 11 during pushing forward.

[0035] The high viscosity mud 31 and the common mud 41 are both prepared by mixing bentonite and water, wherein the amount of bentonite in the high viscosity mud 31 is higher than that in the common mud 41. The preparation method of bentonite and water can be conventionally used in the art, and the specific ratio of the two is selected according to empirical values.

[0036] The high-viscosity mud 31 has a greater viscosity than the ordinary mud 41 and has a better drag reduction effect. When constructing in water-rich hard rock formations, it can effectively resist the scouring and dilution of fissure water and maintain a long-term drag reduction effect.

[0037] The wire brush 20 includes a steel casing 21 and steel bristles 22. The steel casing 21 includes a fixing portion 211 fixed to the outer wall of the high-viscosity mud pipe section 11 and an extension portion 212 extending obliquely from one end of the fixing portion 211 toward the formation soil 100. The extension portion 212 cooperates with the fixing portion 211 to form a receiving space 213 with an opening at one end. The opening of the receiving space 213 faces the formation soil 100. The end of the steel casing 21 with an opening is separated from the formation soil 100 to form a gap 214. One end of the steel bristle 22 is fixed to the fixing portion 211, and the other end passes through the gap 214 and abuts against the formation soil 100.

[0038] The steel casing 21 is welded with steel plates, which ensures the sealing of the closed chamber 30 and prevents leakage of the high-viscosity mud 31 in the closed chamber 30; and has greater rigidity, carries the high-viscosity mud 31 forward synchronously during the jacking process, and is not prone to bending and deformation.

[0039] The existence of the gap 214 can avoid the rigid contact between the steel casing 21 and the formation soil 100 to generate a large resistance. The steel bristles 22 pass through the gap 214 and abut against the formation soil 100, which can form a shielding effect on the gap 214 and avoid the high-viscosity mud 31 from leaking from the gap 214. At the same time, the flexible deformation of the steel bristles 22 can consume the force applied by the formation soil 100 to the steel bristles 22, avoiding excessive resistance.

[0040] Preferably, the wire brush 20 and the high-viscosity mud pipe segment 11 can be fixed by bolts, and the number of bolts is selected according to the diameter of the high-viscosity mud pipe segment 11. A plurality of bolts can be evenly arranged along the circumference of the high-viscosity mud pipe segment 11 to ensure uniform force at all locations. Furthermore, the steel casing 21 and the steel brush bristles 22 can be fixed to the outer wall of the high-viscosity mud pipe segment 11 by using a common bolt.

[0041] The receiving space 213 includes a subspace 2130 located in the extension portion 212, and the cross-sectional area of ​​the subspace gradually increases toward the direction close to the stratum soil 100. The steel bristles 22 are composed of a plurality of steel wires, and each of the steel wires is freely scattered through one end of the slit 214. The number of steel wires in the steel bristles 22 is limited by the area with the smallest cross-sectional area in the subspace 2130. Therefore, in the area with the largest cross-sectional area in the subspace 2130, the steel wires in the steel bristles 22 can obtain a larger spacing distance, which can be used as a deformation space for the steel wires, so as to prevent the steel wires from being greatly bent and deformed under the action of the stratum soil 100 and losing their resilience, thereby shortening their service life.

[0042] Preferably, along the jacking direction of the pipe section 10, the fixing portion 211 is located in front of the extending portion 212, and the angle between the extending portion 212 and the fixing portion 211 is an obtuse angle. The shape of the steel bristles 22 matches the shape of the steel sleeve 21, that is, the steel bristles 22 are also obtuse at the bending position, that is, the bending angle of the steel wire is small, which can ensure the resilience of the steel wire.

[0043] Furthermore, a spring 215 may be provided between the fixed portion 211 and the extending portion 212 , wherein one end of the spring 215 is fixed to the fixed portion 211 , and the other end is fixed to the extending portion 212 , and is used to generate traction force on the extending portion 212 to limit deformation of the extending portion 212 .

[0044] Furthermore, the high-viscosity mud pipe section 11 is evenly provided with four grouting holes 111 along the annular direction, and a reflux hole 112 is provided in the middle position between any two adjacent grouting holes 111. The grouting holes 111 and the reflux hole 112 are both connected to the closed chamber 30. The grouting holes 111 are used to inject high-viscosity mud 31 into the closed chamber 30, and the reflux hole 112 is used to extract the high-viscosity mud 31 in the closed chamber 30.

[0045] When the viscosity of the mud in the closed chamber 30 decreases, the high-viscosity mud 31 in the closed chamber 30 is extracted through the reflux hole 112, and then new high-viscosity mud 31 is re-injected into the closed chamber 30 through the grouting hole 111, thereby replacing the high-viscosity mud 31 in the closed chamber 30 and ensuring the stable performance of the high-viscosity mud 31.

[0046] The injection pressure of the high viscosity mud 31 is higher than the external water pressure, and the injection pipes 113 used by the four injection holes 111 are connected in series in sequence. The connection method of the injection pipe 113 and the injection holes 111 and the return holes 112 is as follows: Figure 5 As shown, Figure 5 Also shown are a grouting pump 114, a return pipe 115 and a mud pool 116. The grouting pipe 113 and the return pipe 115 are both connected to the grouting pump 114, and the grouting pump 114 provides power for mud transportation. The mud pool 116 is connected to the grouting pump 114 through a pipe. When mud needs to be injected, the grouting pump 114 transports the mud in the mud pool 116 to the closed chamber 30 through the grouting pipe 113; when mud needs to be replaced, the grouting pump 114 transports the high-viscosity mud 31 in the closed chamber 30 to the mud pool 116 through the return pipe 115.

[0047] The present application also provides a construction method for top shield construction in water-rich hard rock formations, comprising the following steps:

[0048] Step S1, providing the above-mentioned pipe joint system for top shield construction in water-rich hard rock formations;

[0049] Step S2, providing a grouting pipeline for high-viscosity mud, and injecting high-viscosity mud into the closed chamber; providing a grouting pipeline for ordinary mud, and injecting ordinary mud into the open chamber;

[0050] Step S3, driving the pipe segment to advance, and the high-viscosity mud pipe segment carries the high-viscosity mud in the closed chamber and moves synchronously along the advancement direction;

[0051] Step S4, detecting the viscosity of the high-viscosity mud in the closed chamber, and if the viscosity is lower than a threshold, replacing the high-viscosity mud in the closed chamber.

[0052] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A pipe joint system for top shield construction in water-rich hard rock formations, characterized in that: It comprises a plurality of pipe sections connected in sequence along the jacking direction, wherein the plurality of pipe sections are divided into high-viscosity mud pipe sections and ordinary mud pipe sections, wherein the high-viscosity mud pipe section at least comprises a first pipe section located at the front of the plurality of pipe sections along the jacking direction, and wire brushes are installed at both the front and rear ends of the high-viscosity mud pipe section, wherein the wire brush surrounds the outer wall of the high-viscosity mud pipe section, one end of the wire brush is fixed to the outer wall of the high-viscosity mud pipe section, and the other end of the wire brush extends toward and abuts against the formation soil, and the two wire brushes, the outer wall of the high-viscosity mud pipe section and the formation soil cooperate to form a closed chamber, and the closed chamber is filled with high-viscosity mud; The outer wall of the ordinary mud pipe section cooperates with the formation soil to form an open chamber, and the open chamber is filled with ordinary mud; the wire brush includes a steel casing and steel bristles, the steel casing includes a fixing portion fixed to the outer wall of the high-viscosity mud pipe section and an extension portion extending obliquely from one end of the fixing portion toward the formation soil, the extension portion and the fixing portion cooperate to form a receiving space with one end open, the opening of the receiving space faces the formation soil, the end of the steel casing with the opening is separated from the formation soil to form a gap, one end of the steel bristles is fixed to the fixing portion, and the other end passes through the gap and abuts against the formation soil.

2. The pipe joint system for top shield construction in water-rich hard rock formations according to claim 1 is characterized in that: The high-viscosity mud pipe segment only includes the leading pipe segment located at the front of the plurality of pipe segments along the jacking direction.

3. The pipe joint system for top shield construction in water-rich hard rock formations according to claim 1 is characterized in that: The high-viscosity mud pipe segment includes a first pipe segment located at the front of the plurality of pipe segments along the jacking direction and at least one other pipe segment other than the first pipe segment.

4. The pipe joint system for top shield construction in water-rich hard rock formations according to claim 1, characterized in that: The receiving space includes a subspace located in the extension portion, the cross-sectional area of ​​the subspace gradually increases toward the direction approaching the stratum soil, and the steel bristles are assembled from a plurality of steel wires, each of which passes through one end of the slit and is freely scattered.

5. The pipe joint system for top shield construction in water-rich hard rock formations according to claim 4 is characterized in that: Along the jacking direction of the pipe section, the fixing portion is located in front of the extending portion, and the angle between the extending portion and the fixing portion is an obtuse angle, and the shape of the steel bristles matches the shape of the steel casing.

6. The pipe joint system for top shield construction in water-rich hard rock formations according to claim 1, characterized in that: The high-viscosity mud pipe section is evenly provided with four grouting holes along the annular direction, and a return hole is provided between any two adjacent grouting holes. The grouting holes and the return hole are both connected to the closed chamber. The grouting holes are used to inject high-viscosity mud into the closed chamber, and the return hole is used to extract the high-viscosity mud in the closed chamber.

7. The pipe joint system for top shield construction in water-rich hard rock formations according to claim 6, characterized in that: The grouting pressure of the high-viscosity mud is higher than the external water pressure, and the grouting pipelines used in the four grouting holes are connected in series in sequence.

8. The pipe joint system for top shield construction in water-rich hard rock formations according to claim 6, characterized in that: The high viscosity mud and the ordinary mud are both prepared by using bentonite and water, wherein the amount of bentonite in the high viscosity mud is higher than that in the ordinary mud, and the high viscosity mud and the ordinary mud are grouting by using independent grouting pipelines.

9. A construction method for top shield construction in water-rich hard rock formations, characterized in that: The steps include: Step S1, providing a pipe joint system for top shield construction in water-rich hard rock formations according to any one of claims 1 to 8; Step S2, providing a grouting pipeline for high-viscosity mud, and injecting high-viscosity mud into the closed chamber; providing a grouting pipeline for ordinary mud, and injecting ordinary mud into the open chamber; Step S3, driving the pipe segment to jack up, the high-viscosity mud pipe segment carrying the high-viscosity mud in the closed chamber moves synchronously along the jacking direction; Step S4, detecting the viscosity of the high-viscosity mud in the closed chamber, and if the viscosity is lower than a threshold, replacing the high-viscosity mud in the closed chamber.

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