Single-bin rectangular pipe jacking torsion deviation correction construction method for composite rock-soil foundation

Abstract

The invention relates to a single-bin rectangular pipe jacking torsion deviation rectifying construction method for a composite rock-soil foundation. The method comprises the following steps that supporting pipe piles are driven on the two sides of an inclined pipe joint; a pressure relief hole is formed in the soil body on the inclined side above the pipe joint through a horizontal directional drill; two jacks are installed on the upper side and the lower side of the interior of the inclined pipe joint respectively and connected with steel bars, and the other ends of the steel bars stretch out of the grouting holes and penetrate through the stratum to make contact with the side wall of the pipe pile; determining a pipe joint lubricating material according to the properties of the stratum around the pipe joint so as to reduce the frictional resistance around the pipe joint; the two jacks are controlled to apply equivalent reverse loads synchronously, then a torsional couple is generated to enable the pipe joint to rotate, and the deviation rectifying process is completed. Compared with the prior art, large-area excavation is not needed, the construction period is shortened, and the cost is reduced; in addition, the pipe joint structure does not need to be damaged and holed, the integrity of the structure is kept, and higher applicability to the composite rock-soil stratum environment is achieved.

Description

Technical Field

[0001] This invention relates to the field of civil engineering technology, specifically a method for torsional correction of single-compartment rectangular pipe jacking in composite rock and soil foundations. Background Technology

[0002] Rectangular pipe jacking offers advantages such as smaller excavation volume and faster construction speed, and provides greater space utilization compared to circular pipe jacking. Therefore, it is widely used in soft soil underground engineering projects such as power tunnels, municipal utility tunnels, and underground passages in urban soft soil areas. However, after the rectangular pipe section jacking is completed, factors such as uneven ground hardness, reliance on experience in construction operations, and changes in the external environment can cause uneven settlement or deflection of the pipe section over time. Severe deflection can lead to significant additional stress at the longitudinal joints, causing structural damage and affecting the structure's safety and normal use. Furthermore, this time-delayed deflection cannot be avoided through dynamic correction during the jacking stage.

[0003] After jacking is completed, traditional pipe jacking correction techniques mainly involve large-area excavation and pipe positioning, which suffers from drawbacks such as long construction cycles, high costs, and the need for a large working space on site. When site conditions do not allow for large-area excavation and the structure consists of single-compartment pipe sections with small cross-sections, existing technologies involve installing anchors on the deviated side inside the pipe section and connecting threaded steel bars inserted from inside the pipe section to a tensioning anchoring device on the ground surface, thereby raising the lower side of the pipe section to achieve the goal of repositioning it. This correction method is suitable for pipe sections with highly compressible strata. When the overburden above the pipe section has low compressibility or high fluidity, the lifting amount of the pipe section is limited by the high compressibility modulus of the overburden or horizontal shearing action, making it difficult to achieve the expected correction effect. In addition, this method involves damaging and opening holes in the pipe section and subsequent hole repair, without fully utilizing the pre-reserved channels in the pipe section. Therefore, it is necessary to propose a rectangular pipe jacking correction construction method suitable for different geological conditions, which not only meets the requirements of economic efficiency but also helps to protect the integrity and functionality of the pipe section structure.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] The technical problem to be solved by this invention is to overcome the above-mentioned technical defects and provide a single-compartment rectangular pipe jacking torsion correction construction method for composite rock and soil foundations.

[0006] To solve the above problems, the technical solution of the present invention is: a single-compartment rectangular pipe jacking construction method for correcting deviation in composite rock and soil foundations, comprising the following steps:

[0007] Step 1: Drive support pipe piles on both sides of the inclined pipe section;

[0008] Step 2: Install pressure relief holes in the soil above the inclined pipe section using horizontal directional drilling;

[0009] Step 3: Install two jacks on the upper and lower sides of the inside of the inclined pipe section and connect them with steel rods. The other end of the steel rods extends out of the grouting hole and passes through the stratum to contact the side wall of the support pipe pile.

[0010] Step 4: Determine the lubricating material for the deviated pipe section based on the geological properties around it to reduce the frictional resistance around the deviated pipe section.

[0011] Step 5: Control the two jacks to apply equal and opposite loads simultaneously, thereby generating a torsional couple that causes the skewed pipe section to rotate in the plane, with the correction angle within 4°.

[0012] Preferably, the support pipe piles are distributed on both sides of the inclined pipe section, possessing sufficient horizontal bearing capacity and lateral stiffness.

[0013] Preferably, the soil cover is placed above the deviated pipe section at equal intervals and is formed by drilling and enlarging holes with a horizontal directional drilling rig to reduce the soil pressure on the pipe section during correction.

[0014] Preferably, the two jacks are installed on the upper and lower sides of the inside of the inclined pipe section, respectively, with their center lines aligned with the upper and lower grouting holes of the single-compartment pipe section. Steel bars are fixed at the loading flange ends of the two jacks, with the other end of the steel bars extending out of the grouting hole and passing through the stratum to contact the side wall of the support pipe pile. A jack support is provided at the lower end of the jack, and a steel pad is provided at the rear end of the jack.

[0015] As a preferred option, when the design value of the load applied by the jack is too large, grout can be injected through the grouting hole inside the inclined pipe section to reduce the frictional resistance around the inclined pipe section; among them, compressed air is injected into the strata with high water content such as silty soft soil, and mud is injected into the strata of hard clay or dense sand.

[0016] Preferably, two jacks are synchronously controlled by a PLC system to apply equal loads in stages. The force transmission chain formed by the support pile sidewall, steel bars, and jacks applies a reaction force to the deviated pipe section, thereby creating a torsional couple that drives the deviated pipe section to return to its original position. The design values ​​of the loads applied by the jacks are expressed as follows:

[0017] ;

[0018] in: It is a torsional couple. It is the distance between the center lines of the two jacks. It is the design load value applied by a single jack.

[0019] As a preferred method, the frictional torque of the formation on the deviated pipe section structure is overcome during the slow correction process. Taking the center of the deviated pipe section as the moment center, according to the force analysis of the cross-section of the deviated pipe section, the frictional torque is mainly provided by the tangential frictional force between the formation and the structure. Therefore, the torsional moment of a single-compartment rectangular jacking pipe can be estimated based on the frictional torque generated during the pipe section rotation process, as shown in the following formula:

[0020] ;

[0021] in, It is the coefficient of friction of the contact surface between the strata and the pipe section structure. It is the active earth pressure coefficient. It is the passive earth pressure coefficient. It is the pressure on the pipe section correction side. It is the weight of the pipe section itself. It is the soil pressure on the pipe section. It is the height of the pipe section. It refers to the width of the pipe section.

[0022] Preferably, the cross-section selection should meet the design requirements for column stability. The supports at both ends of the steel bar should be hinged. Taking a circular cross-section as an example, its diameter should meet the following requirement:

[0023] ;

[0024] in, It is the diameter of the steel bar. It is the elastic modulus of the steel bar. This refers to the calculated length of the steel bar.

[0025] The advantages of this invention compared to existing technologies are:

[0026] (1) The present invention only requires the installation of support pipe piles on both sides of the pipe section, without the need to excavate the soil covering the top of the pipe, which saves the cost of earthwork, support and backfilling, significantly shortens the construction period, and minimizes the interference to ground traffic, pipelines and the surrounding environment. It is particularly suitable for urban areas and other places where the construction work surface is limited.

[0027] (2) This invention makes full use of the original grouting holes of the pipe section as the force transmission channel of the jack reaction steel bar, without the need to make any destructive openings to the pipe section structure. This feature completely preserves the integrity of the pipe section structure and the original waterproof system, avoids long-term safety hazards such as structural weakness and leakage that may be caused by openings and subsequent repairs, and ensures the durability of the structure;

[0028] (3) The present invention uses a PLC system to synchronously control two jacks to apply an equivalent reverse load to the single-compartment rectangular pipe section for torsional correction, and determines the injection material according to different stratum characteristics to reduce the surrounding friction resistance and other targeted measures, effectively overcoming the problem of large correction resistance and poor effect in composite rock and soil foundation with uneven softness and hardness.

[0029] (4) The design value of the load applied by the jack of the present invention conforms to the basic laws of geotechnical mechanics, and can generate a torsional couple of controllable size on the cross section of the pipe section. The correction mechanism is clear and applicable to single-compartment small cross section jacking pipe sections with cross section size <4m×5m, and there are no requirements for the jacking length. Attached Figure Description

[0030] Figure 1 This is a flowchart of the pipe section torsion correction construction process of the present invention.

[0031] Figure 2 This is a schematic diagram of the overall construction of the pipe section torsion correction according to the present invention.

[0032] Figure 3 This is a force analysis diagram of the pipe section torsional correction according to the present invention.

[0033] Figure 4 This is a side elevation view of the two pipe sections of the present invention.

[0034] Figure 5 This is a schematic diagram of the top plan of the two pipe sections of the present invention.

[0035] Attached reference numerals: 1. Inclined pipe section; 2. Jack; 3. Steel bar; 4. Pressure relief hole; 5. Support pipe pile; 6. Grouting hole; 7. Steel pad; 8. Jack support; 9. Soil cover. Detailed Implementation

[0036] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. Identical components are indicated by the same reference numerals.

[0037] It should be noted that the terms “front,” “back,” “left,” “right,” “up,” and “down” used in the following description refer to the directions shown in the attached diagram, while the terms “inside” and “outside” refer to the directions toward or away from the geometric center of a specific component, respectively.

[0038] To make the content of this invention easier to understand, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings.

[0039] like Figure 2As shown, a method for torsional correction of a single-compartment rectangular pipe jacking project for composite rock and soil foundations is implemented using a single-compartment rectangular power pipe jacking project as an example. The overburden thickness 9 is 8m, and the deflection angle of the inclined pipe section 1 is 4°. The stratum where the inclined pipe section 1 is located is silty clay with a friction angle of 4°. The method includes the following steps:

[0040] Step 1: Drive support pipe piles 5 on both sides of the inclined pipe section 1; the support pipe piles 5 should have sufficient horizontal bearing capacity and lateral stiffness.

[0041] Step 2: Pressure relief holes 4 are arranged at equal intervals in the soil cover 9 above the deviated pipe section 1. The holes are enlarged by horizontal directional drilling to reduce the soil pressure on the deviated pipe section 1 when it is corrected.

[0042] Step 3: Install two jacks 2 on the upper and lower sides of the inside of the inclined pipe section 1. Both jacks 2 are placed on the jack support 8, and their center lines are aligned with the grouting holes 6 on the upper and lower sides of the single-compartment pipe section, respectively. Steel pads 7 are set behind both jacks 2, and steel rods 3 are fixed at the loading flange ends of the two jacks 2. The other end of the steel rods 3 extends out of the grouting hole 6 and passes through the stratum 9 to contact the side wall of the pipe pile 5.

[0043] Step 4: Grouting from other grouting holes 6 inside the inclined pipe section 1 ( Figure 4 , Figure 5 Injecting compressed air to reduce the frictional resistance around the skewed tube section 1 can be used as an auxiliary measure to correct the torsion of the skewed tube section 1.

[0044] Step 5: Using the center of the pipe section as the moment center, calculate the torsional moment of the single-compartment rectangular jacking pipe based on the frictional torque generated during the slow rotation of pipe section 1, such as... Figure 3 As shown, the specific expression is as follows:

[0045] ;

[0046] in, It is the friction coefficient of the contact surface between the stratum and the pipe section structure, obtained from the direct shear test of the interface between concrete specimens and silty clay. =0.309.

[0047] It is the active earth pressure coefficient. = =0.87.

[0048] It is the passive earth pressure coefficient. = =1.15.

[0049] It is the pressure on the pipe section correction side. =309.76kN.

[0050] It is the weight of the pipe section itself. =297.39kN.

[0051] It is the soil pressure on the pipe section. =1134.3kN.

[0052] It is the height of the pipe section. =4.4m.

[0053] It is the width of the pipe section. =3.3m.

[0054] Step Six: Synchronously control two jacks 2 via the PLC system to apply equal reverse loads step by step. The force transmission chain formed by the support pile 5 sidewall, steel bar 3, and jacks 2 applies a reaction force to the pipe section, thereby creating a torsional couple that drives the tilted pipe section 1 to return to its original position. The design value of the load applied by jacks 2 is expressed as follows:

[0055] ;

[0056] in, It is a torsional couple, calculated in step five. =2063.43kNm.

[0057] It is the distance between the center lines of the two jacks. =1.3m.

[0058] It is the design load value applied by a single jack.

[0059] Step 7: The cross-sectional selection of steel bar 3 should meet the design requirements for column stability. The supports at both ends of steel bar 3 are hinged. Taking a circular cross-section as an example, its diameter should meet the following requirement:

[0060] ;

[0061] in,

[0062] This is the design load value applied by a single jack, calculated in step six. =1587.25kN.

[0063] It is the elastic modulus of the steel bar. =200GPa.

[0064] It is the calculated length of the steel bar. =2m.

[0065] It's the diameter of the steel bar, calculated. =90mm.

[0066] All electrical components mentioned in this article are connected to an external main controller and 220V AC mains power. The main controller can be a conventional known device such as a computer for control. The detailed description of known functions and components is omitted in the specific implementation of this disclosure. To ensure the compatibility of the device, the operating methods used are consistent with the parameters of commercially available instruments.

[0067] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A method for torsional correction construction of single-compartment rectangular pipe jacking for composite rock and soil foundations, characterized in that, Includes the following steps: Step 1: Drive support pipe piles (5) on both sides of the inclined pipe section (1); Step 2: Set pressure relief holes (4) in the soil above the inclined pipe section (1) by horizontal directional drilling; Step 3: Install two jacks (2) on the upper and lower sides of the inside of the inclined pipe section (1) and connect them with steel rods (3). The other end of the steel rod (3) extends out of the grouting hole (6) and passes through the stratum to contact the side wall of the support pipe pile (5). Step 4: Determine the lubricating material of the deviated pipe section (1) based on the geological properties around the deviated pipe section (1) to reduce the frictional resistance around the deviated pipe section (1); Step 5: Control the two jacks (2) to apply equal reverse loads simultaneously, thereby generating torsional couples that cause the skewed pipe section (1) to rotate in the plane, with the correction angle within 4°.

2. The method for torsional correction of single-compartment rectangular pipe jacking in composite rock and soil foundations according to claim 1, characterized in that: The support pipe piles (5) are distributed on both sides of the inclined pipe section (1) and have sufficient horizontal bearing capacity and lateral stiffness.

3. The method for torsional correction of single-compartment rectangular pipe jacking in composite rock and soil foundations according to claim 1, characterized in that: The soil cover (9) is laid above the deviated pipe section (1) at equal intervals. It is formed by drilling and enlarging holes with a horizontal directional drilling rig to reduce the soil pressure on the pipe section during deviation correction.

4. The method for torsional correction of single-compartment rectangular pipe jacking in composite rock and soil foundations according to claim 1, characterized in that: Two jacks (2) are installed on the upper and lower sides of the inside of the inclined pipe section (1), respectively. Their center lines are aligned with the upper and lower grouting holes (6) of the single-compartment pipe section, and steel rods (3) are fixed at the loading flange ends of the two jacks (2). The other end of the steel rod (3) extends out of the grouting hole (6) and passes through the stratum to contact the side wall of the support pipe pile (5). The lower end of the jack (2) is provided with a jack support (8), and the rear end of the jack (2) is provided with a steel pad (7).

5. The method for torsional correction of single-compartment rectangular pipe jacking in composite rock and soil foundations according to claim 1, characterized in that: When the design value of the load applied by the jack (2) is too large, grout can be injected through the grouting hole (6) inside the inclined pipe section (1) to reduce the frictional resistance around the inclined pipe section (1); among them, compressed air is injected into the strata with high water content such as silty soft soil, and mud is injected into the strata of hard clay or dense sand.

6. The method for torsional correction of single-compartment rectangular pipe jacking in composite rock and soil foundations according to claim 1, characterized in that: Two jacks (2) are synchronously controlled by the PLC system to apply equal loads step by step. The force transmission chain formed by the side wall of the support pipe pile (5), the steel bar (3) and the jacks (2) applies a reaction force to the skewed pipe section (1), thereby forming a torsional couple and driving the skewed pipe section (1) to return to its original position. The design value of the load applied by the jacks (2) is expressed as follows: ； in: It is a torsional couple. It is the distance between the center lines of the two jacks (2). It is the design value of the load applied by a single jack (2).

7. The method for torsional correction of single-compartment rectangular pipe jacking in composite rock and soil foundations according to claim 6, characterized in that, During the slow correction process, the frictional torque of the stratum on the deviated pipe section (1) structure is overcome; taking the center of the deviated pipe section (1) as the moment center, according to the force analysis of the cross section of the deviated pipe section (1), the frictional torque is mainly provided by the tangential friction between the stratum and the structure. Therefore, the torsional moment of the single-compartment rectangular jacking pipe can be estimated based on the frictional torque generated during the pipe section rotation process, as shown in the following formula: ； in, It is the coefficient of friction of the contact surface between the strata and the pipe section structure. It is the active earth pressure coefficient. It is the passive earth pressure coefficient. It is the pressure on the pipe section correction side. It is the weight of the pipe section itself. It is the soil pressure on the pipe section. It is the height of the pipe section. It refers to the width of the pipe section.

8. A method for torsional correction of single-compartment rectangular pipe jacking in composite rock and soil foundations according to claim 6, characterized in that, The cross-section selection should meet the design requirements for the stability of the compression member. The support constraint of the steel bar (3) is that both ends are hinged. Taking a circular cross-section as an example, its diameter should meet the following requirements: ； in, It is the diameter of the steel bar. It is the elastic modulus of the steel bar. This refers to the calculated length of the steel bar.

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