Large-diameter sewage pipe support structure at the bottom of the jacking pipe

Abstract

This utility model relates to the field of pipe jacking construction technology, specifically a support structure for a large-diameter sewage pipe at the bottom of a pipe jacking system. It includes a launching well and a receiving well positioned opposite each other on either side of the sewage pipe. A pipe jacking channel spanning the sewage pipe is provided between the launching well and the receiving well. Several guide pipes penetrating the well wall are pre-embedded in either the launching well or the receiving well. Interlocking piles are arranged parallel to each other on both sides of the sewage pipe. Pipe roofs are fixed inside the guide pipes and connected to the interlocking piles. This support structure forms a pipe jacking channel system spanning the sewage pipe through the coordinated arrangement of the launching well and the receiving well. The pre-embedded guide pipes on the side of the well closer to the sewage pipe enable precise positioning and installation of the pipe roofs. Combined with the interlocking piles, a three-dimensional support system is formed, effectively dispersing the concentrated stress of the jacking load on the sewage pipe below.

Description

Technical Field

[0001] This utility model relates to the field of pipe jacking construction technology, specifically a support structure for a large-diameter sewage pipe at the bottom of a pipe jacking system. Background Technology

[0002] In the development of urban underground space, underground structures such as subway entrances and exits often need to pass through areas densely populated with existing municipal pipelines. As urban underground pipe networks become increasingly complex, the safety protection of large-diameter, deeply buried sewage trunk lines, as key nodes in urban drainage systems, has become a crucial issue in underground engineering construction. These pipelines typically handle regional sewage transport, and damage to them could lead to serious environmental and social impacts.

[0003] In practical engineering, when pipe jacking tunnels need to cross existing sewage trunk lines at close range, multiple technical challenges arise: shallow overburden excavation can easily cause ground disturbance, leading to uneven stress on the underlying pipeline; the starting and receiving points of pipe jacking in water-rich and soft strata pose a risk of soil erosion; and the difficulty in controlling the attitude of large-section pipe jacking may exacerbate the compression effect on existing pipelines. Especially for reinforced concrete sewage pipes with an inner diameter of up to 2.6 meters, and where the minimum vertical clearance between the pipe and the jacking structure is less than 1 meter, traditional support methods are insufficient to effectively distribute the jacking load, posing a potential risk of pipe joint leakage or even structural damage.

[0004] In existing technologies, passive protection measures such as ground reinforcement or isolation pile walls are typically used for such close-proximity construction conditions. However, these measures suffer from problems such as long construction periods, high costs, and limited protection effectiveness for existing pipelines. Especially in special cases where the pipe jacking receiving well is adjacent to a sewage pipe, conventional methods struggle to balance the conflict between structural space requirements and pipeline protection, necessitating the establishment of a more effective active protection system. Utility Model Content

[0005] The present invention aims to solve the above problems and thus provide a large-diameter sewage pipe support structure with better protection at the bottom of the jacking pipe.

[0006] The technical solution adopted by this utility model to solve the aforementioned problem is: A support structure for a large-diameter sewage pipe at the bottom of a pipe jacking system includes a launching well and a receiving well arranged opposite each other on both sides of the sewage pipe. A pipe jacking channel spanning above the sewage pipe is provided between the launching well and the receiving well. Several guide pipes penetrating the well wall are pre-embedded in the launching well or the receiving well. Interlocking piles are arranged parallel to each other on both sides of the sewage pipe. A pipe roof is fixed inside the guide pipe and connected to the interlocking piles.

[0007] Compared with the prior art, the outstanding features of this utility model, which adopts the above technical solution, are: This support structure forms a pipe jacking channel system across the sewage pipe through the coordinated arrangement of the launching and receiving wells. A guide pipe is pre-embedded in the well body closer to the sewage pipe to achieve precise positioning and installation of the pipe roof. Combined with interlocking piles, a three-dimensional support system is formed, effectively dispersing the concentrated stress of the jacking load on the sewage pipe below. Compared to traditional passive protection measures, this structure reduces the risk of ground disturbance through an active support mechanism, optimizing the load transfer path within a limited space. It is particularly suitable for close-proximity protection of large-diameter sewage pipes under shallow overburden conditions. The integrity of the pipe roof and interlocking pile fixed support system can alleviate the risk of pipe interface misalignment caused by pipe jacking construction, while avoiding the construction period extension problems caused by ground reinforcement.

[0008] As a preferred embodiment, a further technical solution of this utility model is: Furthermore, the pipe roof comprises several parallel steel pipes, the number of which is equal to the number of guide pipes. The steel pipes penetrate the guide pipes and their axes are parallel to the axis of the jacking channel. The pipe roof's design of parallel steel pipes, matching the number of guide pipes and with their axes parallel to the jacking channel, forms a continuous support system consistent with the jacking direction. This arrangement facilitates the uniform longitudinal load transfer, reducing localized pressure concentration on the sewage pipes below.

[0009] Furthermore, the interlocking piles utilize alternating interlocking of pile A and pile B to form a continuous retaining wall. The interlocking piles, formed by alternating interlocking of reinforced concrete pile A and plain concrete pile B, create a continuous wall that combines structural strength with water-stopping functionality. This achieves seamless interlocking, and the synergistic effect of both effectively controls ground deformation.

[0010] Furthermore, the steel pipe ends are connected to opposite piles A and B, forming a unified support system by linking the pipe roof and interlocking piles. This rigid connection optimizes the load transfer path and utilizes the soil resistance within the pile depth range to share the additional stress caused by pipe jacking construction.

[0011] Furthermore, an I-beam is inserted inside the steel pipe, the steel pipe is filled with cement grout, and the space between the steel pipe and the guide pipe is filled with expanding cement mortar. The I-beam strengthens the overall performance, while the filling of the expanding cement mortar can compensate for the gap between the steel pipe and the guide pipe and enhance the compactness of the contact surface.

[0012] Furthermore, a sealing plate is provided at the outer end of the guide tube, with an air outlet at the upper part of the sealing plate and a grouting hole at the lower part of the sealing plate, through which grout is injected into the interior. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the main structure of an embodiment of the present utility model; Figure 2 This is a three-dimensional structural diagram of an embodiment of the present utility model; Figure 3This is a side view of an embodiment of the present utility model. The following are marked on the diagram: 1. Starting shaft; 2. Guide pipe; 3. Interlocking pile; 4. Steel pipe; 5. Pipe jacking channel; 6. Steel beam; 7. Sewage pipe. Detailed Implementation

[0014] The present invention will be further described below with reference to embodiments, the purpose of which is only to better understand the content of the present invention. Therefore, the examples given do not limit the scope of protection of the present invention.

[0015] A support structure for a large-diameter sewage pipe 7 at the bottom of a jacking pipe includes a launching well 1 and a receiving well arranged opposite each other on both sides of the sewage pipe 7. A jacking pipe channel 5 spanning above the sewage pipe 7 is provided between the launching well 1 and the receiving well. Several guide pipes 2 penetrating the well wall are pre-embedded in the launching well 1 or the receiving well. In this embodiment, the guide pipes 2 are installed on the launching well 1. A horizontally placed steel beam 6 structure is set on the inner side of the well wall where the guide pipes 2 are located. The guide pipes 2 penetrate the steel beam 6. Interlocking piles 3 are arranged parallel to each other on both sides of the sewage pipe 7. The net distance between the interlocking piles 3 and the sewage pipe is 1.2m. A pipe roof is fixed inside the guide pipe 2. The pipe roof is connected to the interlocking piles 3. In order to facilitate the construction of the pipe roof, the inner end of the guide pipe 2 extends out of the steel beam by 400mm, and the bottom plate of the structure is sunk during construction. However, this part needs to be backfilled later. It does not affect the overall quality and appearance. A gap of 0.4m is left at the top of the pipe roof and a gap of 0.5m is left at the bottom.

[0016] Furthermore, the pipe shed comprises several parallel steel pipes 4, each with a thick wall and an outer diameter of 159mm. The gap between adjacent steel pipes is between 200-500mm. The number of steel pipes 4 is equal to that of the guide pipes 2. The steel pipes 4 penetrate the guide pipes 2 and their axes are parallel to the axis of the jacking channel 5. This design of parallel steel pipes 4, matching the number of guide pipes 2 and with their axes parallel to the jacking channel 5, forms a continuous support system aligned with the jacking direction. This arrangement facilitates uniform load distribution along the longitudinal direction, reducing localized pressure concentration on the lower sewage pipe 7.

[0017] Furthermore, the interlocking pile 3 uses A piles and B piles to interlock alternately to form a continuous support wall. The interlocking pile 3 forms a continuous wall with both structural strength and water-stopping function by alternating interlocking of reinforced concrete A piles and plain concrete B piles. The interlocking pile 3 uses C15 ultra-slow-setting concrete. The ultra-slow-setting type needs to meet the requirements of initial setting ≥20h and final setting ≤40h. The arrangement is that two concrete piles (A piles) are interlocked by one concrete pile (B pile). First, two A piles are constructed. Utilizing the characteristics of ultra-slow-setting concrete in A piles, the part of B pile that is embedded with A pile is softly cut when drilling B pile, and B pile is poured to achieve interlocking. The synergistic effect of the two can effectively control the deformation of the stratum.

[0018] Furthermore, the ends of steel pipe 4 are pierced by opposing piles A and B. This design, where the ends of steel pipe 4 are pierced by piles A and B, connects the pipe roof and the interlocking piles 3 into an integrated support system. This rigid connection optimizes the load transfer path and utilizes the soil resistance within the pile depth range to share the additional stress caused by pipe jacking construction. A machine head or drill bit is installed at the head of steel pipe 4, and a spiral drill rod connected to the machine head is installed at the rear. The power of the spiral drill rod is provided by the spiral drilling rig. Inside the steel pipe 4 to be laid, as the spiral drilling rig rotates, the spiral drill rod transmits drilling pressure and torque to the drill bit inside the machine head to cut the soil layer and discharges soil cuttings from the spiral drill rod inside the steel pipe 4 into the working pit. The jacking cylinder pushes the steel pipe 4 forward. The jacking and cutting are carried out simultaneously, pushing the steel pipe 4 of the pipe roof forward segment by segment through piles A and B.

[0019] Furthermore, an I-beam is inserted inside the steel pipe 4, and the steel pipe is filled with M30 cement grout. Expansion cement mortar is filled between the steel pipe 4 and the guide pipe 2. The I-beam strengthens the overall performance, and the filling of expansion cement mortar can compensate for the gap between the steel pipe 4 and the guide pipe 3, and enhance the compactness of the contact surface.

[0020] Furthermore, a sealing plate is provided at the outer end of the guide pipe 2. After the steel pipe is pushed in, the sealing plate is welded. An air outlet is opened at the upper part of the sealing plate, and a grouting hole is opened at the lower part of the sealing plate. Grouting is carried out through the grouting hole. During grouting, the guide pipe is inserted to 50cm at the front end of the pipe curtain, and a backward grouting is adopted. The retraction of the pipe is coordinated with the grouting progress.

[0021] First, the starting well 1 and receiving well are symmetrically constructed on both sides of the sewage pipe 7, and the guide pipe 2 is pre-embedded in the well wall on the side closer to the sewage pipe 7. Then, C15 ultra-slow setting concrete is used to construct interlocking piles 3 in the order of A pile-B pile-A pile. The soft cutting of the un-set A pile by the B pile forms a continuous support wall. Next, the steel pipe 4 with the machine head is pushed in along the guide pipe 2. The soil is cut and pushed in spur by the spiral drill rod, so that the arched steel pipe 4 penetrates the interlocking piles 3 to form an integral support system. After the jacking is completed, I-beams are inserted and a backward segmented grouting process is adopted. Finally, the gap between the steel pipe 4 and the guide pipe 2 is filled with expansive cement mortar, and the port of the guide pipe 2 is sealed with a sealing plate. This forms a three-dimensional support system composed of pipe roof, interlocking piles 3 and grouting body, which transforms the traditional dispersed concentrated stress into uniform load transfer along the jacking pipe axis.

[0022] The above description is only a preferred embodiment of the present utility model and does not limit the scope of the present utility model. All equivalent changes made based on the content of the present utility model specification and its drawings are included within the scope of the present utility model.

Claims

1. A support structure for a large-diameter sewage pipe at the bottom of a jacking pipe, characterized in that: It includes a launching well and a receiving well set opposite each other on both sides of the sewage pipe. A jacking channel spanning the sewage pipe is set between the launching well and the receiving well. Several guide pipes penetrating the well wall are pre-embedded in the launching well or the receiving well. Interlocking piles are set parallel to both sides of the sewage pipe. A pipe roof is fixed in the guide pipe and connected to the interlocking piles.

2. The large-diameter sewage pipe support structure at the bottom of the jacking pipe according to claim 1, characterized in that: The pipe shed consists of several parallel steel pipes, the number of which is equal to the number of guide pipes. The steel pipes pass through the guide pipes and their axes are parallel to the axis of the jacking channel.

3. The large-diameter sewage pipe support structure at the bottom of the jacking pipe according to claim 2, characterized in that: Interlocking piles are formed by alternating interlocking of piles A and B to create a continuous retaining wall.

4. The large-diameter sewage pipe support structure at the bottom of the jacking pipe according to claim 3, characterized in that: The steel pipe passes through the opposite piles A and B at its end.

5. The large-diameter sewage pipe support structure at the bottom of the jacking pipe according to claim 2, characterized in that: An I-beam is inserted into the steel pipe, which is filled with cement grout, and the space between the steel pipe and the guide pipe is filled with expanding cement mortar.

6. The large-diameter sewage pipe support structure at the bottom of the jacking pipe according to claim 2, characterized in that: A sealing plate is provided at the outer end of the guide tube. An air outlet is provided at the upper part of the sealing plate, and a grouting hole is provided at the lower part of the sealing plate.

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