Power pipe gallery jacking pipe construction method convenient for testing internal force and earth pressure

Abstract

The application relates to the technical field of urban underground space, and discloses a power pipe gallery jacking pipe construction method convenient for testing internal force and earth pressure, which comprises the following steps: prefabricating a reinforcing cage and a terminal box mold, welding a reinforcing stress meter on the outer side of the reinforcing cage, binding the terminal box mold on the reinforcing cage, extending a signal transmission line into the inner side of the reinforcing cage through the terminal box mold, hoisting the reinforcing cage into a steel formwork, sticking one end of the terminal box mold to an inner formwork, binding a prefabricated mold on the reinforcing cage and ensuring that the rear end of the prefabricated mold abuts against the inner formwork, pouring concrete into the steel formwork, demolding to form a prefabricated jacking pipe, marking the position of the prefabricated mold, installing an earth pressure cell in the prefabricated mold and sealing the earth pressure cell, introducing a signal transmission line of the earth pressure cell into the inner side of the prefabricated jacking pipe through the prefabricated mold, and taking out a signal transmission line of the reinforcing stress meter from the terminal box mold.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of urban underground space, and particularly relates to a power pipe gallery jacking pipe construction method convenient for testing internal force and earth pressure. BACKGROUND

[0002] Jacking pipe construction is a relatively mature trenchless technology, which is suitable for short-distance construction and is widely used in municipal pipeline engineering, especially rectangular power pipe gallery, which has a utilization rate 20% higher than that of circular power pipe gallery under the same cross-sectional area. During jacking pipe construction of the power pipe gallery, the jacking pipe is mainly affected by water and soil pressure around the pipe section, axial jacking force of the jack, pipe-soil friction and head-on resistance of the machine head, and the stress condition is relatively complex. The jacking force calculation is a crucial link in the design of the entire jacking pipe project, and is directly related to the design requirements such as the strength of the back wall of the working well, the relay interval and the pipe section. If the jacking force calculation is higher than the design index, although it can ensure the smooth progress of the jacking work, it may cause damage to the pipe section or shear failure of the back wall, and in severe cases, it may lead to the failure of the entire project. If the jacking force calculation is lower than the design index, it cannot guarantee the normal jacking construction, and it is also difficult to meet the reasonable progress requirements of the project. Therefore, it is necessary to monitor the internal force of the reinforced concrete jacking pipe and the earth pressure at the pipe-soil interface in real time during the jacking process.

[0003] Chinese patent CN202010388396.7 discloses a jacking pipe machine head and a pipe key position stress monitoring device and method, which monitors the stress state of the jacking pipe by monitoring the strain of the jacking pipe, but cannot directly measure the contact force at the pipe-soil interface, and cannot specifically explore the evolution relationship among the jacking force, the internal force of the jacking pipe and the side earth pressure during the jacking process.

[0004] Chinese patent CN201810931707.2 discloses a comprehensive pipe gallery large-section rectangular jacking pipe construction pipe-soil contact pressure test method, but the earth pressure hole needs to be opened before jacking construction. This method greatly damages the jacking pipe as a whole, and the construction is more complex, so it is difficult to install the earth pressure cell and arrange the lead wire. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application aims to provide a power pipe gallery jacking pipe construction method convenient for testing internal force and earth pressure. The method of installing a prefabricated mold before pouring concrete is adopted to form a hole in advance on the jacking pipe, which solves the problem of difficulty in installing the earth pressure cell and arranging the lead wire on the outer surface of the prefabricated jacking pipe. At the same time, the installation of the junction box mold avoids the influence of slotting and hole opening on the normal use of the jacking pipe, and realizes the real-time measurement of the internal force of the jacking pipe and the side earth pressure of the jacking pipe during the jacking pipe construction process.

[0006] In order to achieve the above object, the present application is realized by the following technical scheme:

[0007] A power pipe gallery jacking pipe construction method convenient for testing internal force and earth pressure, comprising the following steps:

[0008] The prefabricated reinforcement cage and the junction box mold are first welded with the reinforcement stress meter on the outer side of the reinforcement cage, the reinforcement cage is hoisted into the steel formwork, and the junction box mold is adhered to the inner formwork at one end; then the junction box mold is bound to the reinforcement cage, and the signal transmission line is extended to the inner side of the reinforcement cage through the junction box mold;

[0009] The prefabricated mold is bound to the reinforcement cage and ensures that the rear end is against the inner formwork, and the front end of the prefabricated mold is smeared with anchoring glue to find the embedded prefabricated mold after demolding;

[0010] The steel formwork is poured with concrete, and then the prefabricated jacking pipe is formed after demolding, the position of the prefabricated mold is marked, the earth pressure cell is installed in the prefabricated mold and sealed, the signal transmission line of the earth pressure cell is introduced into the inner side of the prefabricated jacking pipe through the prefabricated mold, and the signal transmission line of the reinforcement stress meter is taken out from the junction box mold.

[0011] As a further implementation manner, the reinforcement cage is bound and welded according to the size parameters of the required prefabricated jacking pipe, and the reinforcement stress meter is arranged at the middle position of each side of the reinforcement cage.

[0012] As a further implementation manner, the reinforcement stress meters are longitudinally distributed on each side of the reinforcement cage and two are arranged, the junction box mold is arranged on the same line with the reinforcement stress meters and between the two reinforcement stress meters.

[0013] As a further implementation manner, the junction box mold comprises a junction box, one end of a protective sleeve pipe is connected to the bottom of the junction box, a hole is opened at the junction of the protective sleeve pipe and the junction box to facilitate the wiring of the signal transmission line, the protective sleeve pipe is bound to the reinforcement cage perpendicular to the side of the reinforcement cage, and the signal transmission line of the reinforcement stress meter is extended into the junction box through the protective sleeve pipe, and then the junction box is sealed by gluing on the surface.

[0014] As a further implementation manner, the steel formwork comprises an inner formwork and an outer formwork, AB glue is smeared on the side of the junction box away from the protective sleeve pipe, and then the junction box is adhered to the inner formwork to fix the position of the junction box, and then anchoring glue is uniformly smeared on the joint between the junction box and the outer surface of the inner formwork for reinforcement.

[0015] As a further implementation manner, the prefabricated mold comprises a plastic box, the plastic box is circular, one end of the protective sleeve pipe is fixed to the outer side of the plastic box, and waterproof adhesive tape is wound at the joint between the plastic box and the protective sleeve pipe.

[0016] As a further implementation mode, the prefabricated mold is arranged on each side of the steel reinforcement cage, the protective sleeve is bound on the intersection position of the vertical and horizontal reinforcement in the center of each side of the steel reinforcement cage by using waterproof tape, the protective sleeve is abutted on the inner formwork at the end away from the plastic box during the binding, and the planting glue is evenly applied on the corresponding position of the outer formwork and the end of the plastic box away from the protective sleeve after the binding is completed, so that the embedded prefabricated mold can be found after demolding.

[0017] As a further implementation mode, the position of the prefabricated mold is marked by the planting glue after demolding, the plastic box is excavated to form a hole, the earth pressure cell is installed in the formed circular cavity, the signal transmission line of the earth pressure cell is introduced into the inside of the prefabricated pipe through the protective sleeve, and then the gap around the earth pressure cell is grouted with the planting glue.

[0018] As a further implementation mode, when the earth pressure cell is installed, the earth-facing surface of the earth pressure cell is flush with the outer surface of the concrete.

[0019] As a further implementation mode, after the steel reinforcement stress meter is welded or the earth pressure cell is installed, the frequency reading instrument is connected to the earth pressure cell and the steel reinforcement stress meter to test the availability, and if the reading frequency is found to be greatly different from the calibrated frequency, the instrument is replaced in time to ensure the smooth progress of the test.

[0020] The beneficial effects of the present application are as follows:

[0021] 1. The method for installing the prefabricated mold before pouring the concrete solves the problem of difficulty in installing the earth pressure cell and arranging the lead wire on the outer surface of the prefabricated pipe, and the installation of the terminal box mold avoids the influence of slotting and hole opening on the normal use of the pipe, and realizes the real-time measurement of the internal force of the pipe and the lateral earth pressure of the pipe during the pipe construction.

[0022] 2. The signal transmission line of the steel reinforcement stress meter is protected and fixed, so that the signal transmission line can be found smoothly after the prefabricated pipe is demolded, and the survival rate of the steel reinforcement stress meter is ensured.

[0023] 3. The steel reinforcement stress meter is welded on the pipe steel reinforcement cage, and the stress change of the steel reinforcement during the jacking process is accurately measured, so that the problem of difficulty in measuring the internal force of the pipe during the jacking process is solved.

[0024] 4. The stress is detected by using the frequency reading instrument, the operation is simple, the experimental instrument is light and convenient to carry, one device can monitor the stress state of two sensors at the same time, the device is light and small during use, the jacking process can be detected without affecting the normal construction, and the contact relationship between the pipe-slab-soil interface can be better explored. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings, which form a part of this specification, are included to provide a further understanding of the application, and are incorporated into and constitute a part of this specification. The embodiments of the application, and their

[0026] Figure 1 Fig. 1 is a schematic diagram of the prefabricated pipe body structure in the embodiment of the application;

[0027] Figure 2 Fig. 2 is a top view of the reinforcing cage in the embodiment of the application;

[0028] Figure 3 Fig. 3 is a front view of the reinforcing cage in the embodiment of the application;

[0029] Figure 4 Fig. 4 is an isometric view of the reinforcing cage in the embodiment of the application;

[0030] Figure 5 Fig. 5 is a side view of the reinforcing cage in the embodiment of the application;

[0031] Figure 6 Fig. 6 is a schematic diagram of the junction box mold in the embodiment of the application;

[0032] Figure 7 Fig. 7 is a schematic diagram of the prefabricated mold in the embodiment of the application;

[0033] Figure 8 Fig. 8 is a schematic diagram of the installation of the junction box mold in the embodiment of the application;

[0034] Figure 9 Fig. 9 is a schematic diagram of the earth pressure cell in the embodiment of the application;

[0035] Figure 10 Fig. 10 is a schematic diagram of the installation of the earth pressure cell in the embodiment of the application;

[0036] Figure 11 Fig. 11 is a final effect diagram of the installation of the earth pressure cell in the embodiment of the application.

[0037] In the drawings, the mutual spacing or dimensions are exaggerated to show the positions of the parts, and the schematic diagrams are only for illustration.

[0038] In the drawings, the mutual spacing or dimensions are exaggerated to show the positions of the parts, and the schematic diagrams are only for illustration. DETAILED DESCRIPTION

[0039] It should be noted that the following detailed description is illustrative only, and is intended to further provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0040] Embodiment one

[0041] In a typical embodiment of the present application, referring to Figures 1-11 Fig. 1, a method for pipe gallery jacking construction for conveniently testing internal force and earth pressure, comprising the following steps:

[0042] S1: prefabricate the reinforcement cage 2 and the junction box mold 6, weld the reinforcement stress meter 5 on the outer side of the reinforcement cage 2 first, bind the junction box mold 6 on the side of the reinforcement cage 2, and then extend the signal transmission line of the junction box mold into the inner side of the reinforcement cage;

[0043] S2: hoist the reinforcement cage into the steel formwork 3, and stick one end of the junction box mold 6 to the inner formwork;

[0044] S3: bind the prefabricated mold 8 on the reinforcement cage 2 and ensure that the back end of the prefabricated mold 8 abuts against the inner formwork, and smear the prefabricated mold 8 with anchoring glue 10 at the front end to find the prefabricated mold 8 after demolding;

[0045] S4: pour concrete into the steel formwork 3, and then demold to form the prefabricated jacking pipe 1, mark the position of the prefabricated mold 8, install the earth pressure cell 7 in the prefabricated mold 8 and seal it, and introduce the signal transmission line 14 of the earth pressure cell 7 into the inner side of the prefabricated jacking pipe 1 through the prefabricated mold 8, and take out the signal transmission line 14 of the reinforcement stress meter 5 from the junction box mold 6.

[0046] As shown in Figure 6 Fig. 2, the junction box mold 6 comprises a junction box 17, the bottom of the junction box 17 is connected to one end of two parallel protection sleeves through AB glue 11, and waterproof tape 12 is wound at the connection to prevent water from entering, and the protection sleeves 4 and the junction box 17 are both holed at the connection to facilitate the routing of the signal transmission line 14. The thickness of the junction box 17 is about 25 mm, and the side length is 75 mm. The length of the protection sleeve 4 in the junction box mold 6 is 200 mm, and the diameter is 25 mm.

[0047] As shown in Figure 7 Fig. 3, the prefabricated mold 8 comprises a plastic box 16, which is circular in shape, and one end of the protection sleeve 4 is fixed to the outer side of the plastic box 16 through AB glue 11, and waterproof tape is wound at the connection between the plastic box 16 and the protection sleeve 4. The protection sleeve 4 in this embodiment is made of PVC pipe material.

[0048] In step S1, the relevant size parameters of the prefabricated pipe 1 are determined first, and the prefabricated pipe reinforcement cage 2 is bound and welded according to the design parameters. After the completion of the reinforcement cage 2, the reinforcement cage 2 is in the shape of a cube, which has four sides, and the longitudinal reinforcement in the middle position of the four sides is selected. After the longitudinal reinforcement is cut to the same length as the reinforcement stress meter 5, the longitudinal reinforcement is welded and connected with the reinforcement stress meter 5.

[0049] The reinforcement stress meter 5 is a vibrating wire type reinforcement stress meter, the vibrating wire type reinforcement stress meter 5 has a diameter of 20 mm, a steel sleeve length of 120 mm, a maximum tensile strength of 300 MPa, a maximum compression strength of 200 MPa, and a sensitivity k≤0.10.

[0050] As shown in Figure 3 , the reinforcement stress meter 5 of the embodiment is distributed along the longitudinal direction on each side of the reinforcement cage and two are arranged, the two reinforcement stress meters 5 are located in the middle position of each side of the reinforcement cage and on the same straight line, the junction box mold is on the same straight line with the reinforcement stress meter and is located between the two reinforcement stress meters, and therefore the preferred position of the junction box mold is the center position of each side of the reinforcement cage.

[0051] In order to avoid damage to the signal transmission line 14 of the reinforcement stress meter during concrete pouring and vibrating, the signal transmission line 14 of the reinforcement stress meter 5 is bound to the outside of the reinforcement cage 2 and vertically penetrates the reinforcement cage 2 to reach the inside of the reinforcement cage 2, the transverse position is protected by the protection sleeve 4, and a 20 cm line head is reserved and sealed in the prefabricated junction box mold 6. After completion, the surface of the junction box mold 6 is uniformly coated with the anchoring glue 10 for sealing treatment.

[0052] Specifically, the protection sleeve 4 is bound to the reinforcement cage by using waterproof tape 12 or a strap vertically to the side of the reinforcement cage, and the line head of the signal transmission line 14 of the reinforcement stress meter is inserted into the protection sleeve 4, the signal transmission line penetrates the protection sleeve and the opening on the junction box 17, so that the line head of the signal transmission line of the reinforcement stress meter enters the junction box 17, the junction box 17 is located inside the reinforcement cage 2, and after completion, the surface of the prefabricated junction box 17 is uniformly coated with the anchoring glue 10 for sealing treatment.

[0053] In step S2, the steel mold plate 3 is a pipe pouring mold customized according to the design drawing, which is composed of a bottom mold, a center column, an inner mold plate, an outer mold plate, and a trapezoidal screw assembly. After the prefabricated pipe reinforcement cage 2 is hoisted into the steel mold plate 3, the position of the junction box 17 is selected on the surface of the inner mold plate and the corresponding position is wiped with a towel, then AB glue 11 is applied on the side of the junction box 17 away from the protection sleeve 4 and pasted on the inner mold plate to fix the position of the junction box, and then the anchoring glue is uniformly applied at the joint between the junction box 17 and the outer surface of the inner mold plate for further reinforcement treatment.

[0054] As shown in Figure 5 andFigure 7 As shown, the installation of the junction box mold 6 is completed, and then the installation of the prefabricated mold 8 is performed.

[0055] The length of the protective sleeve 4 in the prefabricated mold 8 is the same as the thickness of the pipe wall concrete at the installation position, and there are two lengths of 250 mm and 330 mm.

[0056] In step S3, the prefabricated mold 8 is arranged on each side of the reinforcement cage 2, and the prefabricated mold 8 is arranged close to the junction box mold 6. After the prefabricated mold 8 is completed, waterproof tape 12 is used to seal the openings at both ends of the protective sleeve 4 to prevent the concrete from invading during grouting. Then, the protective sleeve 4 is tied to the center of each side of the reinforcement cage using waterproof tape 12 at the intersection of the longitudinal and transverse reinforcement. When tying, the end of the protective sleeve 12 away from the plastic box is placed against the inner formwork, and after tying, the outer formwork and the end of the plastic box 16 away from the protective sleeve 4 are evenly coated with anchoring glue to facilitate finding the prefabricated mold 8 after demolding.

[0057] In step S4, after the installation of the junction box mold 6 and the prefabricated mold 8 is completed, the steel formwork 3 is closed and grouted with concrete. After the prefabricated pipe 1 is demolded, the prefabricated mold 8 and the prefabricated junction box mold 6 are found and marked in time. The junction box 17 and the plastic box 16 can be easily found after demolding through anchoring glue 10 or AB glue 11.

[0058] Then, the plastic box 16 is excavated to form a hole, and the earth pressure cell is installed in the circular cavity formed by the plastic box 16. The signal transmission line of the earth pressure cell 7 is introduced into the inside of the prefabricated pipe 1 through the protective sleeve 4. When installing the earth pressure cell 7, the earth surface of the earth pressure cell 7 should be flush with the outer surface of the concrete. Then, the gap around the earth pressure cell 7 is grouted with anchoring glue 10.

[0059] Specifically, the vibrating wire earth pressure cell 7 is pasted in the circular cavity formed by the prefabricated mold 8 with anchoring glue 10. It is noted that when filling the anchoring glue 10, the outer surface of the earth pressure cell 7 should be flush with the outer surface of the prefabricated pipe 1 and all the gaps between them should be filled. After the signal transmission line of the earth pressure cell is introduced into the pipe through the protective sleeve of the prefabricated mold 8, the anchoring glue 10 is used to fill all the gaps inside the protective sleeve to prevent water leakage.

[0060] The prefabricated pipe 1 of the embodiment has an outer dimension of 3160 × 2860 mm (height × width) and a pipe segment thickness of 250 mm or 330 mm. The outer protective layer of the reinforcement cage has a thickness of 50 mm, and the inner protective layer has a thickness of 30 mm. The steel used in the main structure of the reinforcement cage 2 is HRB400 and HPB300 grade steel.

[0061] The earth pressure cell is a vibrating wire earth pressure cell. The size of the earth pressure cell 7 is 88 mm in diameter and 25 mm in thickness, and the range is determined according to the buried depth of the pipe.

[0062] The signal transmission line 14 of the earth pressure cell 7 is introduced into the prefabricated pipe jacking inside the prefabricated mold, and the signal transmission line 14 of the steel stress meter 5 is taken out from the junction box mold 6. At this time, the signal transmission lines of the earth pressure cell 7 and the steel stress meter 5 are located inside the prefabricated pipe jacking 1. The earth pressure cell and the steel stress meter are connected by using a frequency reading instrument to test the availability. If the reading frequency of the steel stress meter is found to be greatly different from the calibrated frequency, timely records and remedial measures are made. If the earth pressure cell has a problem, the problem is checked or the earth pressure cell is replaced in time to ensure the smooth progress of the test. Then the signal transmission line is connected to facilitate subsequent testing work.

[0063] The anchoring adhesive 10 of the embodiment is used according to the specified mixing ratio in the instruction manual, and the adhered parts need to be fixed sufficiently before preliminary solidification to ensure the adhesion quality.

[0064] The AB adhesive 11 of the embodiment is mixed according to the ratio of 1:1. To avoid chemical reaction between the AB adhesive 11 and the waterproof cloth 12, the AB adhesive 11 and the waterproof cloth 12 are used in combination, and the winding and binding of the waterproof cloth 12 are performed after the AB adhesive 11 is completely solidified.

[0065] The strength grade of the concrete of the embodiment is C50. The construction method of pouring and vibrating simultaneously is adopted when pouring the prefabricated pipe jacking 1. After pouring, the surface is ground and the excess concrete is scraped by a putty knife.

[0066] Jacking force calculation method:

[0067]

[0068] In the formula, F0 is the standard value of the jacking force (kN); D1 is the outer diameter of the pipe (m); L is the design jacking length of the pipe (m); f k is the average frictional resistance between the pipe and the soil (kN / m2); N F is the head resistance of the pipe jacking machine.

[0069] Monitoring frictional resistance conversion method: due to the deformation compatibility condition, the strain value of the concrete should be equal to the strain value of the steel bar. Therefore, the total force of a certain cross section of the pipe is

[0070]

[0071] In the formula, Ec is the elastic modulus of the concrete, Es is the elastic modulus of the steel bar, Ac is the cross-sectional area of the concrete; As is the cross-sectional area of the steel bar; ε is the measured steel strain value, and ε = σ / Es.

[0072] The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A method for pipe jacking construction of an electric power pipe gallery facilitating testing of internal force and earth pressure, characterized in that, It comprises the following steps: The prefabricated reinforcement cage and the junction box mold are first welded with the reinforcement stress meter on the outside of the reinforcement cage, the reinforcement cage is hoisted into the steel mold plate, and the junction box mold is adhered to the inner mold plate at one end; then the junction box mold is bound to the reinforcement cage, and the signal transmission line is extended to the inside of the reinforcement cage through the junction box mold; The prefabricated mold is bound to the reinforcement cage and the back end is ensured to be against the inner mold plate, and the front end of the prefabricated mold is smeared with anchoring glue to find the embedded prefabricated mold after demolding; The concrete is poured into the steel mold plate, and then the prefabricated pipe is formed after demolding, the position of the prefabricated mold is marked, the earth pressure cell is installed in the prefabricated mold and sealed, the signal transmission line of the earth pressure cell is introduced into the inside of the prefabricated pipe through the prefabricated mold, and the signal transmission line of the reinforcement stress meter is taken out from the junction box mold; The junction box mold comprises a junction box, one end of a protective sleeve is connected to the bottom of the junction box, and a hole is opened at the connection between the protective sleeve and the junction box to facilitate the wiring of the signal transmission line, the protective sleeve is bound to the reinforcement cage vertically to the side of the reinforcement cage, and the signal transmission line of the reinforcement stress meter is extended to the junction box through the protective sleeve, and then the junction box is sealed by smearing glue on the surface of the junction box; The prefabricated mold comprises a plastic box, the plastic box is circular, one end of a protective sleeve is fixed to the outside of the plastic box, and waterproof adhesive tape is wound around the connection between the plastic box and the protective sleeve; The stress detection is performed using a frequency reading instrument, and one device can monitor the stress state of two sensors at the same time.

2. The method according to claim 1, wherein, The reinforcement cage is bound and welded according to the size parameters of the required prefabricated pipe, and the reinforcement stress meter is arranged at the middle position of each side of the reinforcement cage.

3. The method according to claim 2, wherein, The reinforcement stress meter is longitudinally distributed on each side of the reinforcement cage and two reinforcement stress meters are arranged, the junction box mold is on the same straight line with the reinforcement stress meter and is located between the two reinforcement stress meters.

4. The method according to claim 1, wherein, The steel mold plate comprises an inner mold plate and an outer mold plate, AB glue is smeared on the side of the junction box away from the protective sleeve, and then the junction box is pasted on the inner mold plate to fix the position of the junction box, and then anchoring glue is uniformly smeared on the joint between the junction box and the outer surface of the inner mold plate for reinforcement treatment.

5. The method according to claim 1, wherein, The prefabricated mold is arranged on each side of the reinforcement cage, the protective sleeve is bound to the reinforcement cage at the intersection position of the longitudinal and transverse reinforcement of each side center of the reinforcement cage, the end of the protective sleeve away from the plastic box is against the inner mold plate during binding, and after the binding is completed, anchoring glue is uniformly smeared on the corresponding part of the outer mold plate and the end of the plastic box away from the protective sleeve to facilitate finding the embedded prefabricated mold after demolding.

6. The method according to claim 5, wherein, After demolding, the position of the prefabricated mold is marked by anchoring glue, and a hole is dug in the plastic box, the earth pressure cell is installed in the circular cavity formed, the signal transmission line of the earth pressure cell is introduced into the inside of the prefabricated pipe through the protective sleeve, and then the gap around the earth pressure cell is filled with anchoring glue.

7. The method according to claim 6, wherein, When installing the earth pressure cell, the earth surface of the earth pressure cell should be flush with the outer surface of the concrete.

8. The method according to claim 1, wherein, The frequency reading instrument is connected to the earth pressure cell and the reinforcement stress meter to test the availability, and if the reading frequency is found to be greatly different from the calibrated frequency, timely remedial measures should be taken to ensure the smooth progress of the test.

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