Municipal pipe ditch foundation fixing and water stopping method based on complex geology

Abstract

A municipal pipe ditch foundation fixing and water stopping method based on complex geology comprises the steps that firstly, a steel sheet pile is installed in a foundation pit, and the steel sheet pile is provided with an installation hole exposed out of a soil body; 2, a self-propelled anchor rod penetrates through the mounting hole and is obliquely driven into the soil body; and 3, dry ice powder is injected through the self-propelled anchor rod, so that water at the bottom of the foundation pit is solidified. According to the method, the follow-up recycling work of the steel sheet pile is simplified, and meanwhile the effect of rapid foundation fixing and water stopping is taken into account.

Description

Technical Field

[0001] The present invention relates to the field of municipal pipe trench construction, and particularly to a method for consolidating the foundation and stopping water of a municipal pipe trench based on complex geology. Background Art

[0002] In municipal pipeline engineering, the excavation of pipe trenches is an inevitable process. In order to ensure safety during construction, it is necessary to support the pipe trenches. The support of municipal pipe trenches is an important measure to ensure the safety of personnel, the quality of the project, and the construction progress during the excavation of pipe trenches and subsequent operations.

[0003] Currently, a commonly used method is to use self - advancing anchor rods combined with steel sheet piles for support. Among them, the steel sheet piles are provided with installation holes, and the self - advancing anchor rods pass through the installation holes and are obliquely driven into the side - wall soil mass. Moreover, the self - advancing anchor rods form cement - soil anchor solids through grouting. One end of the self - advancing anchor rod exposed outside the soil mass is locked on the steel sheet pile through a locking nut. For example, the self - advancing jet - grouting anchor - pulled steel sheet pile support structure with the publication number CN213173759U applies this technology. In addition, the penetration and diffusion of cement slurry in the soil mass not only enhance the stability of the structure but also play a role in stopping water to a certain extent. However, before the steel sheet piles are recycled, the self - advancing anchor rods must be removed from the steel sheet piles first. The bonding strength between the self - advancing anchor rods and the cement - soil anchor solids is quite large, which makes the self - advancing anchor rods often be taken out together with the cement - soil anchor solids when being removed, resulting in great difficulties in recycling the steel sheet piles. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, one of the purposes of this application is to provide a method for consolidating the foundation and stopping water of a municipal pipe trench based on complex geology, which simplifies the subsequent recycling work of steel sheet piles and at the same time takes into account the effect of quickly consolidating the foundation and stopping water.

[0005] A method for consolidating the foundation and stopping water of a municipal pipe trench based on complex geology includes: Step 1: Install steel sheet piles in the foundation pit, where the steel sheet piles are provided with installation holes exposed outside the soil mass; Step 2: Pass the self - advancing anchor rods through the installation holes and obliquely drive them into the soil mass; Step 3: Inject dry - ice powder through the self - advancing anchor rods to solidify the water at the bottom of the foundation pit.

[0006] Preferably, after Step 3, there is also Step 4: After the water solidifies, fill heat - insulating components at the orifice of the anchor hole and the inlet of the anchor rod channel of the self - advancing anchor rod.

[0007] Preferably, the injection pressure of the dry - ice powder is 40 MPa - 60 MPa.

[0008] Preferably, the self - advancing anchor rod comprises a hollow anchor rod body, which includes an outer anchor rod body and an inner anchor rod body. The outer anchor rod body is provided with a plurality of exposed grooves that connect its outer surface and inner surface and are arranged circumferentially around its central axis. The inner anchor rod body is arranged inside the outer anchor rod body and is spirally connected to the outer anchor rod body. The inner anchor rod body is provided with a plurality of inner exposed grooves that connect its outer surface and inner surface and are arranged circumferentially around its central axis. The inner anchor rod body has a first position state and a second position state. The inner exposed grooves overlap with the outer exposed grooves when the inner anchor rod body is in the first position state, and the inner exposed grooves are covered by the outer anchor rod body when the inner anchor rod body is in the second position state; In step 2, the self - advancing anchor rod driven into the bottom of the pit is in the second position state; In step 3, the self - advancing anchor rod for injecting dry - ice powder is in the first position state.

[0009] Preferably, the self - advancing anchor rod further comprises an anchor head arranged at the lower part of the outer anchor rod body, and the exposed grooves extend downward along the length direction of the outer anchor rod body to the anchor head.

[0010] Preferably, in step 2, after the self - advancing anchor rod is driven into the soil at the bottom of the pit, the state is that the upper parts of the exposed grooves and the inner exposed grooves are both located in the soil at the bottom of the pit.

[0011] Preferably, at the bottom of the inner wall of the outer anchor rod body, there are lower connecting internal threads and a sealing contact surface above the lower connecting internal threads. On the inner anchor rod body, there are a sealing section that cooperates with the sealing contact surface and a lower thread section connected to the sealing section. The lower thread section has lower connecting external threads that cooperate with the lower connecting internal threads. On the part of the inner wall of the outer anchor rod body outside the steel sheet pile, there are upper connecting internal threads, and on the inner anchor rod body, there are upper connecting external threads that cooperate with the upper connecting internal threads.

[0012] Preferably, there are a plurality of steel sheet piles in step 1, and adjacent steel sheet piles are connected by locking components; Step 2 includes driving a plurality of self - advancing anchor rods for obliquely supporting the steel sheet piles at the joint between the steel sheet piles.

[0013] In the present invention, the self - advancing anchor rod for obliquely supporting the steel sheet pile injects dry - ice powder to solidify the moisture at the bottom of the foundation pit, replacing the way of water - stop by grouting in the existing technology for self - advancing anchor rods. Compared with the existing technology, it can not only ensure the quick effect of solidifying the foundation and stopping water, but also, after the solidified moisture absorbs heat and liquefies, it is convenient to easily screw out the self - advancing anchor rod from the soil, thus simplifying the subsequent recovery work of the steel sheet pile.

[0014] In the present invention, the self-advancing anchor rod is specially designed. Moreover, in step 2, the self-advancing anchor rod driven into the bottom of the pit is in the second position state, which avoids soil from entering the interior of the anchor rod and reduces the possible negative impacts during the injection of dry ice. At the same time, in step 3, the self-advancing anchor rod for injecting dry ice powder is in the first position state, allowing a large amount of dry ice powder to directly and quickly fill the gap between the hollow anchor rod body and the anchor hole, ensuring rapid water stoppage, simplifying the operation steps, and at the same time, ensuring the strength of the hollow anchor rod body when it serves as a support component, ensuring effective support for the steel sheet pile, thereby enhancing the overall foundation strengthening effect.

[0015] In the present invention, the self-advancing anchor rod is specially designed. At the bottom of the inner wall of the outer anchor rod body, there is a lower connecting internal thread and a sealing contact surface above the lower connecting internal thread. On the inner anchor rod body, there are a sealing section that cooperates with the sealing contact surface and a lower thread section connected to the sealing section. The lower thread section has a lower connecting external thread that cooperates with the lower connecting internal thread. On the part of the inner wall of the outer anchor rod body located outside the steel sheet pile, there is an upper connecting internal thread, and on the inner anchor rod body, there is an upper connecting external thread that cooperates with the upper connecting internal thread. Such a design, especially the elaborate design of the sealing section and the sealing contact surface, effectively prevents soil from entering the threaded part between the lower connecting internal thread and the lower connecting external thread, thereby ensuring that the outer anchor rod body can rotate freely relative to the inner anchor rod body. Similarly, the position design of the upper connecting internal thread and the upper connecting external thread outside the steel sheet pile also avoids soil from entering the threaded area, ensuring the smooth rotation of the outer anchor rod body relative to the inner anchor rod body. Such a design not only facilitates the operation of the self-advancing anchor rod but also significantly improves the construction efficiency of foundation strengthening and water stoppage. Brief Description of the Drawings

[0016] Figure 1 is a flowchart of the foundation strengthening and water stoppage method in the present invention; Figure 2 is a schematic diagram of the position of the self-advancing anchor rod and the steel sheet pile; Figure 3 is a schematic structural diagram of the self-advancing anchor rod in the first position state; Figure 4 is a schematic structural diagram of the self-advancing anchor rod in the second position state; Figure 5 is a diagram of the positional relationship between the self-advancing anchor rod and the bottom of the foundation pit; Figure 6 is a cross-sectional view of the self-advancing anchor rod; Detailed Description of the Invention

[0017] The following will further illustrate the present invention with specific embodiments in conjunction with the drawings. Embodiment

[0018] A method for strengthening the foundation and stopping water in a municipal pipe trench based on complex geology, such asFigure 1 As shown, it includes: Step 1: Install sheet piles 2 in the foundation pit. Among them, the sheet piles 2 are provided with installation holes exposed outside the soil mass. There are a large number of these sheet piles, and adjacent sheet piles are tightly connected by locking components, which can be bolt fasteners, but are not limited to this; Step 2: Pass the self-advancing anchor rod 1 through the installation hole and obliquely drive it into the soil mass; Step 3: Inject dry ice powder through the self-advancing anchor rod 1, and the injection pressure should be maintained between 40 MPa and 60 MPa. The injection of dry ice powder will cause the moisture at the bottom of the foundation pit to solidify quickly, thus achieving an excellent water-stop effect. And when the solidified moisture absorbs heat and liquefies, it can facilitate the easy rotation of the self-advancing anchor rod out of the soil mass, thus simplifying the subsequent recovery work of the sheet piles. In contrast, in the existing technology, the cement soil anchor body formed by grouting through the self-advancing anchor rod has too strong a bonding strength with the surface of the anchor rod, and the self-advancing anchor rod is often taken out together with the cement soil anchor body when being removed, resulting in great difficulties in the recovery of the sheet piles.

[0019] Finally, for the positions of the sheet piles and the self-advancing anchor rods, refer to Figure 2 as shown.

[0020] After Step 3 is completed, Step 4 will be carried out: After the moisture solidifies, fill the orifice of the anchor hole and the entrance of the anchor rod channel of the self-advancing anchor rod with heat-insulating components. The anchor hole refers to the hole formed in the soil mass when the self-advancing anchor rod is driven into the soil mass. The choice of heat-insulating components can be diverse. Heat-insulating cotton is a common option, but is not limited to it. The design of this step is crucial. It can effectively prevent heat exchange between the inside and outside of the anchor hole and also prevent heat exchange between the inside and outside of the anchor rod channel, thus avoiding the re-liquefaction of the solidified moisture before the operation in the municipal pipe trench is completed, and ensuring the stability and safety of the construction process.

[0021] The content of Step 2 includes: Drive self-advancing anchor rods for obliquely supporting the sheet piles at the joint between the sheet piles. Such a design ensures that even in areas such as the joints of the sheet piles where water seepage is likely to occur, the moisture can be quickly solidified after injecting dry ice, thus laying a solid foundation for the smooth progress of the entire project.

[0022] The self-advancing anchor rod includes some well-known structures such as a hollow anchor rod body 11 and an anchor head 12. The anchor head 12 is arranged at the lower part of the outer anchor rod body 111. In this embodiment, the self-advancing anchor rod is further designed and optimized, resulting in significant changes in Step 2 and other related steps.

[0023] Specifically, as Figure 3-4As shown, the hollow anchor rod body 11 of this self-advancing anchor rod has an outer anchor rod body 111. Multiple exposed grooves 1111 are designed on the surface of the outer anchor rod body 111. These grooves communicate from the outer surface to the inner surface and are circumferentially distributed around its central axis. The hollow anchor rod body 11 also includes an inner anchor rod body 112, which is arranged inside the outer anchor rod body 111 and is helically connected to the outer anchor rod body 111. That is, the inner wall of the outer anchor rod body 111 is provided with internal threads, and the outer wall of the inner anchor rod body 112 is provided with external threads. The inner anchor rod body 112 is a hollow rod, and the end of the inner anchor rod body 112 can inject dry ice through the access of dry ice injection equipment. There are also multiple inner exposed grooves 1121 on the inner anchor rod body 112. These grooves also communicate with its inner and outer surfaces and are circumferentially distributed. Due to the unique thread structure, the inner anchor rod body 112 can freely move up and down inside the outer anchor rod body 111, so that the inner anchor rod body 112 has two specific position states: the first position state and the second position state. When the inner anchor rod body 112 is in the first position state, the inner exposed grooves 1121 on it will be precisely aligned with the outer exposed grooves 1111 on the outer anchor rod body 111 to form an overlapping structure; when the inner anchor rod body 112 moves to the second position state, the inner exposed grooves 1121 will be completely covered by the outer anchor rod body 111 and hidden therein.

[0024] In step 2, the self-advancing anchor rod driven into the bottom of the pit is in the second position state. At this time, a large amount of soil is prevented from entering the inside of the anchor rod, reducing the possible negative impacts during dry ice injection. In step 3, the self-advancing anchor rod is converted to the first position state. At this time, the gap of the hollow anchor rod body 11 significantly increases, enabling a large amount of dry ice powder to be filled directly and quickly into the gap between the hollow anchor rod body 11 and the anchor hole. This design not only ensures rapid water stoppage but also simplifies the operation steps. Since the outer anchor rod body 111 and the inner anchor rod body 112 are connected by a screwing method, even when larger gaps, namely the inner exposed grooves 1121 and the outer exposed grooves 1111, are opened, the connection between the outer anchor rod body 111 and the inner anchor rod body 112 is equivalent to increasing the wall thickness of the hollow anchor rod body 11. This structural design ensures the strength of the hollow anchor rod body 11 when it is used as a supporting component, ensuring effective support for the steel sheet pile and thus enhancing the overall foundation strengthening effect. In contrast, traditional hollow anchor rod bodies 11 usually have smaller apertures on the surface for dry ice to be filled into the gap between the hollow anchor rod body 11 and the anchor hole because larger apertures may weaken the strength of the anchor rod, increase the difficulty of driving into the soil, and reduce the supporting force on the steel sheet pile. However, when the aperture is small, the injected dry ice is extremely easy to be blocked due to water freezing at the hole position and is not easy to spread widely into the gap between the hollow anchor rod body 11 and the anchor hole, resulting in an unsatisfactory water stoppage effect.

[0025] The exposed groove 1111 extends downward along the length direction of the outer anchor rod body 111 to the anchor head 12.

[0026] In Step 2, the state of the self-advancing anchor rod after being driven into the soil at the bottom of the pit is as follows: the upper parts of the exposed groove 1111 and the internally exposed groove 1121 are both located in the soil at the bottom of the pit. For details, refer to Figure 5 the illustration shown below.

[0027] As Figure 6 shown in the illustration, at the bottom of the inner wall of the outer anchor rod body 111, there are a lower connecting internal thread 1112 and a sealing contact surface 1113 located above the lower connecting internal thread 1112. On the inner anchor rod body 112, there are a sealing section 1122 that mates with the sealing contact surface 1113 and a lower thread section 1123 connected to the sealing section 1122. The lower thread section 1123 has a lower connecting external thread that mates with the lower connecting internal thread 1112. On the part of the inner wall of the outer anchor rod body 111 outside the steel sheet pile, there is an upper connecting internal thread 1114, and on the inner anchor rod body 112, there is an upper connecting external thread 1124 that mates with the upper connecting internal thread 1114. With such a design, especially the elaborate design of the sealing section 1122 and the sealing contact surface 1113, it effectively prevents soil from entering the threaded part between the lower connecting internal thread 1112 and the lower connecting external thread, thereby ensuring that the outer anchor rod body 111 can rotate freely relative to the inner anchor rod body 112. Similarly, the position design of the upper connecting internal thread 1114 and the upper connecting external thread 1124 outside the steel sheet pile also avoids soil from entering the threaded area, guaranteeing the smooth rotation of the outer anchor rod body 111 relative to the inner anchor rod body 112. Such a design not only facilitates the operation of the self-advancing anchor rod but also significantly improves the construction efficiency of foundation fixation and water stoppage.

[0028] The above embodiments only describe the preferred implementation modes of the present invention and do not limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various variations and improvements made by ordinary technicians in the art to the technical solutions of the present invention should all fall within the protection scope of the present invention. The technical content claimed by the present invention has been fully recorded in the claims.

Claims

1. A method for solidifying the foundation and preventing water seepage of municipal pipe trenches based on complex geology, characterized in that: Comprising: Step 1: Install steel sheet piles in the foundation pit, wherein the steel sheet piles are provided with installation holes exposed outside the soil body; Step 2: Pass the self-advancing anchor through the installation hole and obliquely drive it into the soil body; Step 3: Inject dry ice powder through the self-advancing anchor to solidify the moisture at the bottom of the foundation pit.

2. The method for solidifying foundation and preventing water leakage of municipal pipe ditches based on complex geology according to claim 1, characterized in that, After Step 3, there is also Step 4: After the moisture solidifies, fill heat-insulating components at the orifice of the anchor hole and the inlet of the anchor rod channel of the self-advancing anchor.

3. A method for solidifying the foundation and stopping water in municipal pipe trenches based on complex geology according to claim 1, characterized in that The injection pressure of the dry ice powder is 40 MPa - 60 MPa.

4. A method for fixing the foundation and preventing water leakage of municipal pipe trenches based on complex geology according to claim 1, characterized in that, The self-advancing anchor comprises a hollow anchor rod body (11), the hollow anchor rod body (11) comprises an outer anchor rod body (111) and an inner anchor rod body (112). A plurality of outer exposed grooves (1111) are arranged on the outer anchor rod body (111) in a circumferential arrangement around its central axis and communicate its outer surface with its inner surface. The inner anchor rod body (112) is arranged inside the outer anchor rod body (111) and is spirally connected to the outer anchor rod body (111). A plurality of inner exposed grooves (1121) are arranged on the inner anchor rod body (112) in a circumferential arrangement around its central axis and communicate its outer surface with its inner surface. The inner anchor rod body (112) has a first position state and a second position state. The inner exposed grooves (1121) overlap with the outer exposed grooves (1111) when the inner anchor rod body (112) is in the first position state, and the inner exposed grooves (1121) are covered by the outer anchor rod body (111) when the inner anchor rod body (112) is in the second position state; In Step 2, the self-advancing anchor driven into the bottom of the pit is in the second position state; In Step 3, the self-advancing anchor for injecting dry ice powder is in the first position state.

5. A method for solidifying the foundation and stopping water of a municipal pipe trench based on complex geology according to claim 4, characterized in that, The self-advancing anchor further comprises an anchor head (12) arranged at the lower part of the outer anchor rod body (111), and the outer exposed grooves (1111) extend downward along the length direction of the outer anchor rod body (111) to the anchor head (12).

6. The method for solidifying foundation and preventing water leakage of municipal pipe ditches based on complex geology according to claim 4, characterized in that, In Step 2, the state after the self-advancing anchor is driven into the soil at the bottom of the pit is that the upper parts of the outer exposed grooves (1111) and the inner exposed grooves (1121) are both located in the soil at the bottom of the pit.

7. A method for fixing the foundation and preventing water leakage of a municipal pipe trench based on complex geology according to claim 4, characterized in that, At the bottom of the inner wall of the outer anchor rod body (111), there is a lower connecting internal thread (1112) and a sealing contact surface (1113) located above the lower connecting internal thread (1112). On the inner anchor rod body (112), there are a sealing section (1122) that cooperates with the sealing contact surface (1113) and a lower thread section (1123) connected to the sealing section (1122). The lower thread section (1123) has a lower connecting external thread that cooperates with the lower connecting internal thread (1112). On the part of the inner wall of the outer anchor rod body (111) outside the steel sheet pile, there is an upper connecting internal thread (1114), and on the inner anchor rod body (112), there is an upper connecting external thread (1124) that cooperates with the upper connecting internal thread (1114).

8. A method for solidifying the foundation and preventing water leakage of a municipal pipe trench based on complex geology according to claim 1, characterized in that, There are multiple steel sheet piles in Step 1, and adjacent steel sheet piles are connected by locking components; Step 2 includes: Driving a plurality of self-advancing anchors for obliquely supporting the steel sheet piles at the joint between the steel sheet piles.

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