CN116858584B - Multifunctional pipe jacking model test device and test method - Google Patents

Abstract

The invention provides a multifunctional jacking pipe model test device and a test method, which relate to the field of underground geotechnical engineering tests, and include: a multi-posture pipe segment; a multi-section model box, wherein opposite side walls are respectively provided with an inlet and an outlet, an open partition plate is provided between the inlet and the outlet, and a pipe segment hole is provided on the open partition plate for the multi-posture pipe segment to pass through; a power structure, including a jack and a pressure sensor, wherein the jack is provided on one side of the multi-section model box close to the inlet, the jack is used to push the multi-posture pipe segment to move toward the outlet, and the pressure sensor is installed between the free end of the jack and the multi-posture pipe segment; a data acquisition system, which is used to connect signals with the jack and the pressure sensor, the multi-section model box can be used for various jacking tests, and can simulate the pipe segments connected to each other, so as to realize the simulation of the force transmission characteristics caused by the change of the contact area of the multi-posture pipe segment during the jacking process.

Description

Multifunctional pipe jacking model test device and test method

Technical Field

The invention relates to the field of underground geotechnical engineering tests, and in particular to a multifunctional pipe jacking model test device and a test method.

Background technique

In recent years, with the acceleration of the development and utilization of underground space, the pipe jacking method, as a key trenchless technology, has been widely used. For pipe jacking projects under complex engineering geological conditions, the existing relevant theories are difficult to accurately predict the interaction between force and deformation, and simple field tests are often uncertain and random and difficult to repeat. Therefore, it is necessary to design indoor model tests to accurately grasp the changing laws during the pipe jacking process and provide reference and guidance for actual construction.

A rectangular jacking pipe model test device discloses a model test box, a jacking platform, a press, a pressure plate, a prefabricated model pipe segment and a grouting system. The invention device has a simple structure and is easy to use, but the invention patent cannot achieve pipe segment contact simulation and complex formation simulation.

A pipe jacking model test device discloses a test bench, a spliced test box, a pipe jacking model, a lateral loading device, a grouting system and a data acquisition system; the invention device can accurately test the settlement of soil and the change of internal pressure during the pipe jacking process, but the invention patent cannot obtain dynamic surface deformation data.

Summary of the invention

The invention provides a multifunctional pipe jacking model test device and a test method, the purpose of which is to solve the problem of contact force transmission of multi-attitude pipe segments during jacking and the problem of simulated jacking in complex formations.

In order to achieve the above object, an embodiment of the present invention provides a multifunctional pipe jacking model test device, comprising:

Multi-position tube section;

A multi-section model box, with an inlet and an outlet respectively arranged on opposite side walls, a plurality of open partitions arranged between the inlet and the outlet, adjacent open partitions being used to fill different soil layers, and pipe segment holes being arranged on the open partitions for the multi-position pipe segments to pass through;

The power structure includes a jack and a pressure sensor. The jack is arranged on one side of the multi-segment model box close to the hole entrance. The jack is used to push the multi-posture pipe section to move toward the hole exit. The pressure sensor is installed between the free end of the jack and the multi-posture pipe section.

Data acquisition system, used to connect with jack and pressure sensor signals.

Preferably, the multifunctional jacking pipe model test device also includes a supporting reaction force structure arranged at the entrance of the cave, the supporting reaction force structure includes a supporting reaction force bracket, the supporting reaction force bracket is used to be placed on a table, and a reaction force sleeve for multi-posture pipe sections to pass through is provided on the supporting reaction force bracket, a plurality of supporting units of different heights are arranged between the inner wall and the outer wall of the reaction force sleeve, a force plate is overlapped on the supporting unit, and the jack is arranged on the force plate.

Preferably, the multifunctional jacking pipe model test device further comprises a funnel, which is arranged above the multi-segment model box and is used for filling soil into the multi-segment model box.

Preferably, the multi-posture pipe segment comprises two interconnected pipe segments, and the end surfaces of the two interconnected pipe segments present the same structure.

Preferably, the end surface of the pipe segment has one of an upward inclination structure, a downward inclination structure, a top contact structure, a bottom contact structure and a full contact structure.

The present application also provides a test method for simulating the forces under different contact areas of multi-posture pipe segments, using the aforementioned multi-functional pipe jacking model test device, including:

S1. Place the opening partition plate in the multi-segment model box, and keep the pipe segment opening above the horizontal midline of the opening partition plate, and connect the end faces of the two pipe segments by using an outer sleeve to form different abutment states, wherein a strain gauge is provided on one of the pipe segments, and the strain gauge is arranged around the axial direction of the pipe segment;

S2. Connect the data acquisition system and the power structure, and fill the multi-segment model box with soil;

S3. Control the jacking pressure of the jack, obtain the value of the pressure sensor, read the strain value of the pipe segment, and complete the recording of the stress and deformation data of the pipe segment under the first-level load;

S4. Change the jacking pressure of the jack, repeat step S3, and record the stress and deformation data of the pipe segment under different jacking pressures;

S5. Replace the pipe segments with different end faces and repeat steps S1-S4.

The present application also provides another test method for simulating a multi-posture pipe segment jacking test, using the aforementioned multifunctional pipe jacking model test device, including:

The multifunctional pipe jacking model test device also includes a micro earth pressure sensor, a total station and a machine head connected with the data acquisition system signal;

The test method includes the following steps:

S1. placing the opening partition plate in the multi-segment model box, and keeping the pipe segment opening above the horizontal midline of the opening partition plate, and filling soil of different materials between each opening partition plate in the multi-segment model box to form different soil layers;

S2. The end faces of the two pipe sections are connected by an inner sleeve to form different abutment states, wherein a strain gauge is provided on one of the pipe sections and arranged around the axial direction of the pipe section;

S3. Paste a reflective sticker inside the pipe segment, and collect the initial data of the reflective sticker and the first deformation data of the upper surface of the soil layer before jacking;

S4. A machine head is installed on the end face of the front pipe segment for excavation, a micro soil pressure sensor is set on the machine head, and the multi-attitude pipe segment is pre-jacked into the soil layer to obtain data from the micro soil pressure sensor, then the micro soil pressure sensor is removed, and a rotation sensor and a time sensor are set on the pipe segment to construct a relationship curve between the rotation number and time;

S5. The multi-posture pipe segment is pushed into the multi-segment model box to obtain the second deformation data of the upper surface of each soil layer and the multi-posture pipe segment axis motion data, and the motion and deflection trajectory of the multi-posture pipe segment during the motion process is obtained by comparing the initial data;

S6. In step S1, a downward force is applied to different soil layers to simulate different deep burial conditions, and steps S2-S5 are repeated;

S7. Install pipe sections with different roughness, repeat steps S1-S6, and conduct a test on the effect of roughness on the frictional resistance of multi-position pipe sections under different deep burial conditions.

Preferably, the device further comprises a 3D imaging camera;

A plurality of characteristic points are arranged on the upper surface of each soil layer, and a 3D imaging camera photographs the characteristic points to obtain first deformation data and second deformation data of each soil layer.

Preferably, during the filling process of each soil layer, the funnel is located at the same height.

The above scheme of the present invention has the following beneficial effects:

In this application, the multi-section model box can be used for a variety of jacking tests, and can simulate the interconnected pipe sections, realizing the simulation of the force transmission characteristics caused by the change of contact area of the multi-position pipe sections during the jacking process. At the same time, the multi-section model box is provided with an open partition plate, which can simulate the simulation of complex soil layers, which is closer to the real environment.

Other features and advantages of the present invention will be described in detail in the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a multifunctional pipe jacking model test device;

FIG2 is a schematic diagram of a support reaction structure;

FIG3 is a schematic diagram of a support unit;

FIG4 is a schematic diagram of different end faces of a pipe segment;

Figure 5 is a schematic diagram of the connection of the pipe joint through the inner sleeve or the outer sleeve

FIG6 is a schematic diagram of the installation of a strain gauge;

Figure 7 is a curve showing the relationship between the rotation speed and the jacking distance.

[Description of Reference Numerals]

1-multi-attitude pipe joint, 11-pipe joint, 12-strain gauge, 14-inner sleeve, 15-outer sleeve, 16-pressure sensor, 2-multi-segment model box, 21-entrance, 22-exit, 31-jack, 4-data acquisition system, 51-support reaction bracket, 52-reaction sleeve, 531-anchor nail, 532-support nail, 54-force plate, 541-clip, 6-funnel, 7-total station, 8-machine head, 9-3D imaging camera.

Detailed ways

In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

As shown in Fig. 1-6, an embodiment of the present invention provides a multifunctional pipe jacking model test device, including a multi-posture pipe segment 1, a multi-section model box 2, a power structure and a data acquisition system 4. The top of the multi-section model box 2 is open, and an inlet 21 and an outlet 22 are respectively arranged on the opposite side walls of the multi-section model box 2, and a plurality of detachable open partitions are arranged between the inlet 21 and the outlet 22. The open partitions divide the multi-section model box 2 into a plurality of spaces for filling soil, and each space can be filled with soil of different materials for simulating complex strata, and the pipe segment openings are arranged on the open partitions. The multi-posture pipe segment 1 can pass through the inlet 21, the pipe segment opening and the outlet 22 in sequence.

The aforementioned power structure includes a jack 31 and a pressure sensor 16. The jack 31 is arranged on one side of the multi-segment model box 2 close to the inlet 21. The jack 31 is used to push the multi-posture pipe segment 1 to move toward the outlet 22. The pressure sensor 16 is installed between the free end of the jack 31 and the multi-posture pipe segment 1.

The data acquisition system 4 is used for signal connection between the jack 31 and the pressure sensor 16 .

In the present application, the inner wall of the multi-section model box 2 is provided with a plurality of slots for snapping in the opening partition plates, and simulation of different jacking distances and working conditions is achieved by inserting different numbers of opening partition plates and filling soil between the opening partition plates.

Furthermore, the multifunctional jacking pipe model test device also includes a support reaction force structure, which is arranged at the entrance 21 of the cave, and the support reaction force structure includes a support reaction force bracket 51, which is used to be placed on a table, and a reaction force sleeve 52 for the multi-posture pipe section 1 to pass through is arranged on the support reaction force bracket 51, and a plurality of support units of different heights are arranged between the inner wall and the outer wall of the reaction force sleeve 52, and a force plate 54 is overlapped on the support unit, and the jack 31 is arranged on the force plate 54.

The reaction force support structure is used to adjust the height of the jack 31 and provide a reaction force for the jack 31 , and the force position of the jack 31 acting on the multi-posture pipe segment 1 is adjusted by adjusting the height of the reaction force support structure.

In this embodiment, by changing the overlap of the force plate 54 on the support units at different heights and changing the position of the loading point of the jack 31 on the multi-posture pipe segment 1, the influence of different loading positions on the force law during the jacking process of the multi-posture pipe segment 1 is explored.

In this embodiment, the support unit includes anchors 531 and support pins 532, wherein the support pins 532 are used to connect the inner wall and the outer wall of the reaction frame 52, so that the inner wall and the outer wall of the reaction frame 52 are coaxial. A plurality of anchors 531 are arranged between the inner wall and the outer wall of the reaction frame 52, and the plurality of anchors 531 are at different heights between the inner wall and the outer wall of the reaction frame 52, so as to adjust the height of the support plate 54.

Preferably, in this embodiment, a clip 541 is provided on the force plate 54 to prevent the jack 31 from falling off during the jacking process.

Preferably, the multifunctional jacking pipe model test device further comprises a funnel 6, which is arranged above the multi-segment model box 2 and is used to fill soil into the multi-segment model box 2 to form different soil layers between adjacent open partition plates.

The aforementioned multi-posture pipe segment 1 includes at least two interconnected pipe segments 11, and the end surfaces of the two interconnected pipe segments 11 present the same structure. Referring to Figure 4, the end surface of the pipe segment 11 has one of an upward inclination structure, a downward inclination structure, a top contact structure, a bottom contact structure and a full contact structure. Among them, the upward inclination structure includes an upward inclination angle of 60° and an upward inclination angle of 75°. The downward inclination structure includes a downward inclination angle of 60° and a downward inclination angle of 75°. The top contact structure is a protrusion on the upper end of the end surface of the pipe segment 11, and the bottom contact structure is a protrusion on the lower end of the end surface of the pipe segment 11. The full contact structure is that both the upper and lower ends of the end surface of the pipe segment 11 are protruding.

The present application also provides a test method for simulating the forces of the multi-posture pipe segment 1 under different contact areas, using the aforementioned multi-functional pipe jacking model test device, comprising the following steps:

S1. Place the open partition plate in the multi-segment model box 2, and the pipe segment opening is located above the horizontal center line of the open partition plate to ensure that the pipe segment and the pipe segment opening are misaligned. Use the outer sleeve 15 to connect the end faces of the two pipe segments 11 to form different abutment states, such as using two 60° upwardly inclined pipe segments 11 for connection, the inclination angles of the two pipe segments 11 abut against each other, and form a V-shaped space above the connection of the two pipe segments 11. Use the inner sleeve 14 to ensure the contact between adjacent pipe segments 11, which can be used for force transmission of the pipe segments 11. A strain gauge 12 is provided on one of the pipe segments 11, and the strain gauge 12 is arranged around the axial direction of the pipe segment 11. In this embodiment, the strain gauge 12 is a strain gauge sensor.

S2. Connect the data acquisition system 4 and the power structure;

S3. Control the jacking pressure of the jack 31, obtain the value of the pressure sensor 16 and the strain value of the pipe segment 11, and complete the recording of the stress and deformation data of the pipe segment 11 under the first-level load.

S4. Change the jacking pressure of the jack 31, repeat step S3, and record the stress deformation data of the pipe section 11 under different jacking pressures;

S5. Replace the pipe segment 11 with a different end face and repeat steps S1-S4.

The present application provides a test method that can set different contact structures of the multi-posture pipe segment 1 to simulate the force transmission characteristics caused by the change of the contact area of the multi-posture pipe segment 1 during the jacking process.

The present application also provides another test method for simulating a multi-posture pipe segment 1 jacking test, using the aforementioned multi-functional pipe jacking model test device, comprising the following steps:

The multifunctional pipe jacking model test device also includes a micro soil pressure sensor, a total station 7, a 3D imaging camera 9 and a machine head 8, wherein the micro soil pressure sensor and the total station 7 are used for signal connection and acquisition systems.

S1. Place the open partition plate in the multi-segment model box 2, and keep the pipe segment opening above the horizontal center line of the open partition plate, ensure that the pipe segment and the pipe segment opening are directly opposite each other, fill the soil of different materials between each open partition plate in the multi-segment model box 2, and form soil layer 1, soil layer 2 and soil layer 3 respectively to simulate the complex soil layer environment.

S2. The end faces of two pipe sections 11 are connected by means of inner sleeves 14 to form different abutment states, wherein a strain gauge 12 is provided on one of the pipe sections 11, and the strain gauge 12 is arranged around the axial direction of the pipe section 11. In this embodiment, the strain gauge 12 is a strain gauge type sensor.

The use of the inner sleeve 14 can avoid the generation of additional frictional resistance during the jacking process.

S3. Paste reflective stickers inside the pipe segment 11, and collect the initial position of the reflective stickers and the first deformation data of the upper surface of each soil layer before jacking. The total station 7 can obtain the light signal of the reflective stickers, and then obtain the change law of the axis of the pipe segment 11 when the multi-attitude pipe segment 1 is jacked.

S4. A machine head 8 is installed on the end face of the front pipe segment 11 for excavation. A micro soil pressure sensor is arranged on the machine head 8. After the data of the micro soil pressure sensor is obtained when the multi-attitude pipe segment 1 is pre-pushed into each soil layer, the micro soil pressure sensor is removed, and a speed sensor and a time sensor are arranged on the pipe segment 11 to construct a curve of the relationship between the speed and time.

In step S4, the machine head 8 is kept on standby during pre-jacking to avoid affecting the micro soil pressure sensor, and the machine head 8 is started to work during the jacking process.

S5. The multi-posture pipe segment 1 is pushed into the multi-segment model box 2 to obtain the second deformation data of the upper surface of each soil layer and the axial motion data of the multi-posture pipe segment 1, and the motion trajectory and deflection trajectory of the multi-posture pipe segment 1 during the motion process are obtained by comparing the initial data.

In steps S3 and S5, the first deformation data and the second deformation data are obtained in the following manner: a plurality of feature points are set on the upper surface of each soil layer, and the 3D imaging camera 9 periodically takes pictures and compares each feature point to obtain the variation of the first deformation data and the second deformation data.

A group of reference points (A, B, C) are set in each of the three soil layers. Each group of reference points is set with three characteristic points. Each characteristic point is used to feedback the deformation data of the corresponding soil layer, forming a relationship curve between the rotation speed and the jacking distance as shown in Figure 7, where the black dots represent the soil pressure detected by the pressure sensor 16, and the rectangular frame points represent the rotation speed under the current pressure.

S6. In step S1, a downward force is applied to different soil layers to simulate different deep burial conditions, and steps S2 and S5 are repeated.

In this step, more soil can be evenly filled on different soil layers or weights or other counterweights can be applied to the soil layers.

S7. Install pipe segments 11 with different roughness, repeat steps S1-S6, and conduct friction test on multi-position pipe segments 1 under different deep burial conditions. When repeating step S1, the funnel 6 should be located at the same height to ensure that the thickness and density of each soil layer in each test are the same.

The roughness of the pipe segment 11 may be determined based on the actual roughness of the pipe segment 11 during construction, or a plurality of roughness analogy groups may be artificially set.

The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims (8)

1. A multifunctional pipe jacking model test device, characterized in that it comprises: Multi-position tube segment (1); A multi-segment model box (2) is provided with an inlet (21) and an outlet (22) on opposite side walls, a plurality of open partitions are provided between the inlet (21) and the outlet (22), different soil layers are filled between adjacent open partitions, and pipe segment holes are provided on the open partitions for the multi-posture pipe segments (1) to pass through; The power structure comprises a jack (31) and a pressure sensor (16), wherein the jack (31) is arranged on a side of the multi-segment model box (2) close to the hole inlet (21), the jack (31) is used to push the multi-posture pipe section (1) to move in the direction of the hole outlet (22), and the pressure sensor (16) is installed between the free end of the jack (31) and the multi-posture pipe section (1); A data acquisition system (4) for signal connection with the jack (31) and the pressure sensor (16); The multifunctional pipe jacking model test device also includes a support reaction force structure arranged at the hole entrance (21), the support reaction force structure including a support reaction force bracket (51), the support reaction force bracket (51) is used to be placed on a table, a reaction force sleeve (52) for the multi-position pipe section (1) to pass through is arranged on the support reaction force bracket (51), a plurality of support units of different heights are arranged between the inner wall and the outer wall of the reaction force sleeve (52), a force plate (54) is overlapped on the support unit, and the jack (31) is arranged on the force plate (54). 2. The multifunctional pipe jacking model test device according to claim 1 is characterized in that the multifunctional pipe jacking model test device also includes a funnel (6), and the funnel (6) is arranged above the multi-segment model box (2) to fill soil into the multi-segment model box (2). 3. The multifunctional pipe jacking model test device according to claim 2 is characterized in that: the multi-posture pipe segment (1) comprises two interconnected pipe segments (11), and the end surfaces of the two interconnected pipe segments (11) present the same structure. 4. The multifunctional jacking pipe model test device according to claim 3 is characterized in that the end surface of the pipe segment (11) has one of an upward inclination structure, a downward inclination structure, a top contact structure, a bottom contact structure and a full contact structure. 5. A test method for simulating the forces of pipe sections with different contact areas in multiple postures, using the multifunctional pipe jacking model test device according to claim 4, characterized in that it comprises: S1. The opening partition plate is placed in the multi-segment model box (2), and the pipe segment opening is kept above the horizontal center line of the opening partition plate. The end faces of the two pipe segments (11) are connected by means of an outer sleeve (15) to form different abutment states. The pipe segments and the pipe segment openings are arranged in a staggered manner. A strain gauge (12) is arranged on one of the pipe segments (11), and the strain gauge (12) is arranged around the axial direction of the pipe segment (11); S2. Connecting the data acquisition system (4) and the power structure; S3. Control the jacking pressure of the jack (31), obtain the value of the pressure sensor (16), read the strain value of the pipe section (11), and complete the recording of the stress deformation data of the pipe section (11) under the primary load; S4. Change the jacking pressure of the jack (31), repeat step S3, and record the force and deformation data of the pipe segment (11) under different jacking pressures; S5. Replace the pipe segment (11) with a different end face and repeat steps S1-S4. 6. A test method for simulating a multi-position pipe jacking test, using the multifunctional pipe jacking model test device of claim 4, characterized in that it comprises: The multifunctional pipe jacking model test device also includes a micro soil pressure sensor connected to the data acquisition system (4) for signal, a total station (7) and a machine head (8); The test method includes the following steps: S1. The opening partition is placed in the multi-segment model box (2), and the pipe segment opening is kept above the horizontal midline of the opening partition, the pipe segment and the pipe segment opening are arranged opposite each other, and soil of different materials is filled between each opening partition in the multi-segment model box (2) to form different soil layers; S2. The end faces of the two pipe sections (11) are connected by means of an inner sleeve (14) to form different abutment states, wherein a strain gauge (12) is provided on one of the pipe sections (11), and the strain gauge (12) is arranged axially around the pipe section (11); S3. Paste a reflective sticker inside the pipe section (11), and collect the initial data of the reflective sticker and the first deformation data of the upper surface of the soil layer before jacking; S4. A machine head (8) is installed on the end surface of the front pipe section (11), a micro soil pressure sensor (16) is arranged on the machine head (8), and after the multi-attitude pipe section (1) is pre-pushed into the soil layer to obtain data from the micro soil pressure sensor (16), the micro soil pressure sensor (16) is removed, a rotation speed sensor and a time sensor are arranged on the pipe section (11), and the machine head (8) is used for pre-pushing to construct a curve of the relationship between the rotation speed and time; S5. When the multi-posture pipe segment (1) is pushed into the multi-segment model box (2), the second deformation data of the upper surface of each soil layer and the axial motion data of the multi-posture pipe segment (1) are obtained, and the motion and deflection trajectory of the multi-posture pipe segment (1) during the motion process are obtained by comparing the initial data; S6. In step S1, a downward force is applied to different soil layers to simulate different deep burial conditions, and steps S2-S5 are repeated; S7. Install pipe segments (11) with different roughness, repeat steps S1-S6, and conduct a test on the effect of roughness on the frictional resistance of multi-position pipe segments (1) under different deep burial conditions. 7. The test method according to claim 6, characterized in that the device further comprises a 3D imaging camera (9); A plurality of characteristic points are arranged on the upper surface of each soil layer, and a 3D imaging camera (9) photographs the characteristic points to obtain first deformation data and second deformation data of each soil layer. 8. The test method according to claim 7 is characterized in that during the filling process of each soil layer, the funnel (6) is located at the same height.