Method for constructing multidirectional sandy drainage channel in soft soil in model test box

Abstract

The invention discloses a method for constructing a multidirectional sandy drainage channel in soft soil in a model test box. According to the method, a supporting unit and a high-pressure sand blasting unit installed on the upper portion of the supporting unit are adopted; the supporting unit comprises a bottom supporting frame and a rotating base; the high-pressure sand blasting unit comprises a lifting rack, and a sand blasting pipeline is mounted on the lifting rack and synchronously ascends and descends along with the lifting rack, so that the sand blasting pipeline can be inserted into soft soil of the model test box for sand blasting. During testing, the model test box is installed on the rotating base, and a vertical nozzle or an L-shaped nozzle is installed at an outlet in the bottom of the sand blasting pipeline according to needs: when the vertical nozzle is selected, a vertical sandy drainage channel is constructed in soft soil through sand blasting along with the lifting motion of the sand blasting pipeline and the lifting rack; when the L-shaped nozzle is selected, a transverse sandy drainage channel is constructed in soft soil through sand blasting, and the rotation angle of the model test box is adjusted by rotating the base, so that the transverse sandy drainage channel is arranged in different directions.

Description

Technical Field

[0001] This invention belongs to the field of geotechnical engineering testing technology, specifically relating to a method for constructing multi-directional sandy drainage channels in soft soil within a model test chamber. Background Technology

[0002] Drainage consolidation is a commonly used method for soft soil foundation treatment, and after years of research and development, it has been widely applied in practical engineering. Vertical drainage bodies, as a key component in the effectiveness of drainage consolidation, provide vertical drainage channels and facilitate vacuum transfer. Currently, the commonly used vertical drainage body is a plastic drainage board. While it has good drainage effects in the early stages, problems arise in the later stages, such as bending and clogging of the drainage board, the formation of "soil columns" around the drainage board, long foundation reinforcement time, and poor results. Based on the above analysis, to address the problems of unsatisfactory reinforcement depth and drainage board clogging in soft soil reinforcement using drainage consolidation, research and analysis of new reinforcement technologies are needed. A novel reinforcement technology, the high-pressure jet sand multi-directional drainage consolidation method, is proposed to reduce the clogging effect in drainage consolidation and improve its reinforcement efficiency. However, how to simulate the construction of multiple sandy drainage channels in soft soil remains a technical problem that needs to be solved. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for constructing multi-directional sandy drainage channels in soft soil within a model test chamber. This method can construct multi-directional sandy drainage channels in soft soil within a model test chamber through a sandblasting process.

[0004] This invention is achieved through the following technical solution: A method for constructing multi-directional sandy drainage channels in soft soil within a model test chamber, the method employing a support unit and a high-pressure sandblasting unit installed on top of the support unit; The support unit includes a bottom support frame, and a rotating base is provided on the bottom plate of the bottom support frame; The high-pressure sandblasting unit includes an upper cover frame, a sandblasting pipe lifting support frame, a lifting rack, a rack lifting drive mechanism, and a sandblasting pipe. The upper cover frame is installed above the bottom support frame of the support unit, the sandblasting pipe lifting support frame is installed on the upper cover frame, the lifting rack is vertically slidably installed in the sandblasting pipe lifting support frame, and the lifting rack is driven to move vertically up and down by the rack lifting drive mechanism. The sandblasting pipe is fixedly installed on the lifting rack and moves up and down synchronously with the lifting rack. During the experiment, soft soil for testing is filled into the model test chamber, which is then installed on a rotating base. The sandblasting pipe is connected to the sandblasting machine. Then, depending on the needs, a vertical nozzle or an L-shaped nozzle is installed at the bottom outlet of the sandblasting pipe. When a vertical nozzle is selected, the sandblasting pipe and lifting rack move up and down as they are inserted into the soft soil of the model test chamber, creating a vertical sandy drainage channel. When an L-shaped nozzle is selected, a horizontal sandy drainage channel is created by sandblasting the soft soil inside the model test chamber. The rotation angle of the model test chamber is adjusted by rotating the base to achieve the arrangement of horizontal sandy drainage channels in different directions.

[0005] In the above technical solution, the rotating base has the following structure: it includes a base, a turntable mounted on the base, and a geared disc circumferentially mounted on the turntable, the geared disc meshing with a drive gear. Furthermore, the drive gear is connected to a hand-cranked input shaft, which drives the drive gear to rotate.

[0006] In the above technical solution, the sandblasting pipe enters the sandblasting pipe lifting support frame through the sandblasting pipe guide wheel. The sandblasting pipe guide wheel consists of two opposing rollers, and the sandblasting pipe is located between these two rollers, thereby guiding the sandblasting pipe and enabling it to smoothly follow the lifting rack.

[0007] In the above technical solution, the rack lifting drive mechanism adopts a hand-cranked drive mechanism, including a hand-cranked drive shaft and a mounting box. The lifting rack is vertically slidably installed in the mounting box, and a main gear is provided in the mounting box. The main gear meshes with the lifting rack. The hand-cranked drive shaft is horizontally arranged, and the front end of the hand-cranked drive shaft meshes with the main gear through a gear set. When the hand-cranked drive shaft is rotated, power is transmitted to the main gear, and the main gear drives the lifting rack to move up and down.

[0008] In the above technical solution, a lifting balancer is also installed on the top of the sandblasting pipe lifting support frame. The lifting balancer's pull head is connected to the lifting rack, so that the lifting rack and the sandblasting pipe remain balanced during lifting and lowering, achieving stable suspension.

[0009] In the above technical solution, a data acquisition sensor is installed inside the model test chamber to collect data on the changes in parameters of the soft soil during the test in real time.

[0010] In the above technical solution, the data acquisition sensors include: pressure sensor, displacement sensor, pore water pressure sensor and water content sensor.

[0011] The method for constructing multi-directional sandy drainage channels in soft soil within the model test chamber, as described above, includes the following steps: Step 1: Install a vertical nozzle at the bottom outlet of the sandblasting pipe; Step 2: Drive the lifting rack down, so that the lifting rack carries the sandblasting pipe into the soft soil of the model test box, and insert the vertical nozzle at the bottom of the sandblasting pipe into the set depth. Step 3: Turn on the sandblasting machine and simultaneously drive the lifting rack to rise, which will move the vertical nozzle upward and form a vertical sandy drainage channel in the soft soil of the model test box. When the vertical nozzle rises to the middle position of the model test box, turn off the sandblasting machine and stop the movement of the lifting rack. Record the depth of the vertical nozzle at this time. Step 4: Drive the lifting rack to continue rising, raise the vertical nozzle out of the model test box, then replace the L-shaped nozzle, and drive the lifting rack down again to the depth position recorded in Step 3. Then turn on the sandblasting machine, lay out a horizontal sand drainage channel, and turn off the sandblasting machine after the channel is formed. Step 5: Drive the lifting rack upwards to raise the L-shaped nozzle out of the model test box. Then replace the vertical nozzle and drive the lifting rack downwards again to the depth position of the horizontal sandy drainage channel constructed in the previous step. Then turn on the sandblasting machine and drive the lifting rack upwards at the same time to move the vertical nozzle upwards. Continue to construct a section of vertical sandy drainage channel in the soft soil. When the vertical nozzle rises to the set height position, turn off the sandblasting machine and stop the movement of the lifting rack. Record the depth of the vertical nozzle at this time. Step 6: Drive the lifting rack to continue rising, raise the vertical nozzle out of the model test chamber, then replace the L-shaped nozzle, and drive the lifting rack down again to the depth position recorded in Step 5, and drive the rotating base to adjust the rotation angle of the model test chamber; then turn on the sandblasting machine, lay out a new transverse sand drainage channel with a different direction from the previous transverse sand drainage channel, and turn off the sandblasting machine after forming the channel. Step 7: Repeat steps 5 and 6 to continue constructing vertical sandy drainage channels and horizontal sandy drainage channels in different directions in the soft soil until the last section of the vertical sandy drainage channel extends out of the soft soil surface.

[0012] The advantages and beneficial effects of this invention are as follows: This invention realizes the dynamic process of constructing multi-directional sandy drainage channels in soft soil in a laboratory setting. Different forms of sandy drainage channels can be constructed according to requirements, thus providing a foundation for further research on the relationship between multi-directional sandblasting drainage channels and the drainage and consolidation effects on soft soil foundations. Furthermore, this invention is simple to operate, has a clear principle, and is easy to implement. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the combined state of the support unit and the high-pressure sandblasting unit used in this invention.

[0014] Figure 2 This is a top view of the rotating base used in this invention.

[0015] Figure 3 This is a front view of the rotating base used in this invention.

[0016] Figure 4 This is a flowchart of the steps of the method of the present invention.

[0017] For those skilled in the art, other related figures can be obtained from the above figures without any creative effort. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below with reference to specific embodiments.

[0019] This embodiment designs a method for constructing multi-directional sandy drainage channels in soft soil within a model test chamber. The method employs a support unit and a high-pressure sandblasting unit.

[0020] See appendix Figure 1 The support unit includes a bottom support frame 9, on the bottom plate of the bottom support frame 9, a rotating base 12 is provided, and the model test box 10 (preferably, the model test box is barrel-shaped, also known as a model test barrel) is placed on the rotating base 12, and the rotating base 12 drives the model test box 10 to rotate.

[0021] See appendix Figure 2 and attached Figure 3 In a preferred embodiment, the rotating base 12 may have the following structure: it includes a base 121, on which a turntable 122 is mounted. A geared disc 123 is circumferentially mounted on the turntable 122. The geared disc 123 meshes with a drive gear 124. When the drive gear 124 rotates, it drives the turntable 122 to rotate, thereby rotating the model test chamber 10 on it. Further, the drive gear 124 is connected to a hand-cranked input shaft 125, which drives the drive gear 124 to rotate. Alternatively, the drive gear 124 may also be driven by a motor.

[0022] The high-pressure sandblasting unit is installed on the upper part of the support unit to realize the layout of vertical and horizontal sand drainage channels in the soft soil inside the model test box 10.

[0023] For details, please see the appendix. Figure 1The high-pressure sandblasting unit includes an upper cover frame 8, a sandblasting pipe lifting support frame 7, a lifting rack 4, a rack lifting drive mechanism 5, and a sandblasting pipe 1. The upper cover frame 8 is installed on the bottom support frame 9 of the support unit. Preferably, the two are quickly connected by a snap-fit ​​method, which also facilitates quick disassembly (i.e., disconnection). The sandblasting pipe lifting support frame 7 is preferably a long frame structure, vertically set on the upper cover frame 8. The lifting rack 4 is vertically slidably installed in the sandblasting pipe lifting support frame 7. The lifting rack 4 is connected to the rack lifting drive mechanism 5, which drives the lifting rack 4 to move vertically up and down. The sandblasting pipe 1 is fixedly installed on the lifting rack 4 along the edge by a snap-fit ​​or other connection method, and moves up and down synchronously with the lifting rack 4, so that the sandblasting pipe 1 can be inserted into the soft soil of the model test box 10 in the support unit for sandblasting. Furthermore, the sandblasting pipe 1 enters the sandblasting pipe lifting support frame 9 through the sandblasting pipe guide wheel 2. Inside the support frame 7, the sandblasting pipe guide wheel 2 consists of two opposing rollers, with the sandblasting pipe 1 located between these two rollers, guiding the sandblasting pipe 1 so that it can smoothly follow the movement of the lifting rack 4. The bottom outlet of the sandblasting pipe 1 is equipped with a vertical nozzle and an L-shaped nozzle 6, which are selected according to actual needs during the test: when the vertical nozzle is selected (the vertical nozzle is installed vertically downwards on the bottom outlet of the sandblasting pipe 1), as the sandblasting pipe 1 and the lifting rack 4 move up and down, sandblasting is performed in the soft soil inside the model test chamber 10 to construct a vertical sandy drainage channel; when the L-shaped nozzle 6 is selected (the L-shaped nozzle 6 is installed on the bottom outlet of the sandblasting pipe 1, and the L-shaped nozzle 6 is bent at 90 degrees to achieve horizontal spraying), sandblasting is performed in the soft soil inside the model test chamber 10 to construct a horizontal sandy drainage channel, and the rotation angle of the model test chamber 10 can be adjusted by rotating the base 12, allowing horizontal sandy drainage channels to be arranged in different directions.

[0024] In a preferred embodiment, the rack and pinion lifting drive mechanism 5 adopts a hand-cranked drive mechanism, including a hand-cranked drive shaft 51 and a mounting box 52. The lifting rack 4 is vertically slidably installed in the mounting box 52. A main gear 53 is provided in the mounting box 52, and the main gear 53 meshes with the lifting rack 4. The hand-cranked drive shaft 51 is arranged horizontally, and the front end of the hand-cranked drive shaft 51 meshes with the main gear 53 through a gear set. When the hand-cranked drive shaft 51 is rotated, power is transmitted to the main gear 53, and the main gear 53 drives the lifting rack 4 to move up and down.

[0025] As a preferred embodiment, a lifting balancer 3 (or a hovering balancer) is further provided on the top of the sandblasting pipe lifting support frame 7. The lifting balancer 3 is connected to the lifting rack 4, so that the lifting rack 4 and the sandblasting pipe 1 remain balanced during lifting and lowering, and achieve stable hovering.

[0026] As a preferred embodiment, the lifting rack 4 is further arranged coaxially with the model test chamber 10 (that is, the lifting rack 4 is located in the direction of the central axis of the model test chamber 10).

[0027] The method for constructing multi-directional sandy drainage channels in soft soil within the model test chamber using the aforementioned support unit and high-pressure sandblasting unit is described in the appendix. Figure 4 The specific steps are as follows: Step 1: Fill the model test chamber 10 with soft soil for testing, and then place the model test chamber 10 stably on the rotating base 12 of the support unit; install the high-pressure sandblasting unit on the support unit, connect the sandblasting pipe 1 of the high-pressure sandblasting unit to the sandblasting machine, and install a vertical nozzle at the bottom outlet of the sandblasting pipe 1.

[0028] Step 2: Drive the lifting rack 4 to descend, so that the lifting rack 4 carries the sandblasting pipe 1 into the soft soil of the model test box 10, so that the vertical nozzle at the bottom of the sandblasting pipe 1 is inserted to the set depth (preferably close to the bottom of the soft soil).

[0029] Step 3: Turn on the sandblasting machine and simultaneously drive the lifting rack 4 to rise, which will move the vertical nozzle upward and form a vertical sandy drainage channel in the soft soil of the model test chamber 10. When the vertical nozzle rises to the middle position of the model test chamber 10, turn off the sandblasting machine and stop the movement of the lifting rack 4, and record the depth of the vertical nozzle at this time.

[0030] Step 4: Drive the lifting rack 4 to continue rising, raise the vertical nozzle out of the model test chamber 10, then replace the L-shaped nozzle 6, and drive the lifting rack 4 to descend to the depth position recorded in step 3. Then turn on the sandblasting machine, lay out a horizontal sand drainage channel, and turn off the sandblasting machine after the channel is formed.

[0031] Step 5: Drive the lifting rack 4 to rise, raising the L-shaped nozzle 6 out of the model test chamber 10. Then replace the vertical nozzle and drive the lifting rack 4 to descend to the depth of the horizontal sandy drainage channel constructed in the previous step. Then turn on the sandblasting machine and drive the lifting rack 4 to rise, moving the vertical nozzle upward to continue constructing a vertical sandy drainage channel in the soft soil. When the vertical nozzle rises to the set height, turn off the sandblasting machine and stop the movement of the lifting rack 4. Record the depth of the vertical nozzle at this time.

[0032] Step 6: Drive the lifting rack 4 to continue rising, raising the vertical nozzle out of the model test chamber 10. Then replace the L-shaped nozzle 6, and drive the lifting rack 4 to descend to the depth position recorded in step 5. Drive the rotating base 12 to adjust the rotation angle of the model test chamber 10. Then turn on the sandblasting machine and lay out a new transverse sand drainage channel with a different direction from the previous transverse sand drainage channel. After forming the channel, turn off the sandblasting machine.

[0033] Step 7: Repeat steps 5 and 6 to continue constructing vertical sandy drainage channels and horizontal sandy drainage channels in different directions in the soft soil until the last section of the vertical sandy drainage channel extends out of the soft soil surface.

[0034] Furthermore, after constructing all the sandy drainage channels, the high-pressure sandblasting unit is removed, and then geotextile and pressure plate are laid on the soft soil surface. A downward pressure load is applied to the pressure plate to simulate the various loads borne by the foundation in actual engineering, so that the soft soil is under pressure and squeezed for drainage. The data acquisition sensors in the model test chamber 10 are used to collect the parameter changes of the soft soil in real time during the test, including but not limited to the following parameters: load on the soft soil (collected by pressure sensor), soft soil compression deformation (collected by displacement sensor), pore water pressure (collected by pore water pressure sensor), soft soil moisture content (collected by moisture content sensor), etc.

[0035] For ease of explanation, spatial relative terms such as “up,” “down,” “left,” and “right” are used in the embodiments to describe the relationship of one element or feature shown in the figures relative to another element or feature. It should be understood that, in addition to the orientations shown in the figures, spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figures is inverted, an element described as being “down” of other elements or features would be positioned “up” of those other elements or features. Therefore, the exemplary term “down” can encompass both up and down orientations. The device may be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein can be interpreted accordingly. Moreover, relational terms such as “first” and “second” are used merely to distinguish one component from another that has the same name, and do not necessarily require or imply any such actual relationship or order between the components.

[0036] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.

Claims

1. A method for constructing multi-directional sandy drainage channels in soft soil within a model test chamber, characterized in that: The method employs a support unit and a high-pressure sandblasting unit mounted on top of the support unit; The support unit includes a bottom support frame, and a rotating base is provided on the bottom plate of the bottom support frame; The high-pressure sandblasting unit includes an upper cover frame, a sandblasting pipe lifting support frame, a lifting rack, a rack lifting drive mechanism, and a sandblasting pipe. The upper cover frame is installed above the bottom support frame of the support unit, the sandblasting pipe lifting support frame is installed on the upper cover frame, the lifting rack is vertically slidably installed in the sandblasting pipe lifting support frame, and the lifting rack is driven to move vertically up and down by the rack lifting drive mechanism. The sandblasting pipe is fixedly installed on the lifting rack and moves up and down synchronously with the lifting rack. During the experiment, soft soil for testing is filled into the model test chamber, which is then installed on a rotating base. The sandblasting pipe is connected to the sandblasting machine. Then, depending on the needs, a vertical nozzle or an L-shaped nozzle is installed at the bottom outlet of the sandblasting pipe. When a vertical nozzle is selected, the sandblasting pipe and lifting rack move up and down as they are inserted into the soft soil of the model test chamber, creating a vertical sandy drainage channel. When an L-shaped nozzle is selected, a horizontal sandy drainage channel is created by sandblasting the soft soil inside the model test chamber. The rotation angle of the model test chamber is adjusted by rotating the base to achieve the arrangement of horizontal sandy drainage channels in different directions.

2. The method for constructing multi-directional sandy drainage channels in soft soil within a model test chamber according to claim 1, characterized in that: The structure of the rotating base is as follows: it includes a base, a turntable is mounted on the base, a geared disc is mounted around the turntable, and the geared disc meshes with a drive gear.

3. The method for constructing multi-directional sandy drainage channels in soft soil within a model test chamber according to claim 2, characterized in that: The drive gear is connected to a hand-cranked input shaft, which drives the drive gear to rotate.

4. The method for constructing multi-directional sandy drainage channels in soft soil within a model test chamber according to claim 1, characterized in that: The sandblasting pipe enters the sandblasting pipe lifting support frame through the sandblasting pipe guide wheel. The sandblasting pipe guide wheel consists of two opposing rollers, and the sandblasting pipe is located between these two rollers, which guides the sandblasting pipe and allows it to smoothly follow the movement of the lifting rack.

5. The method for constructing multi-directional sandy drainage channels in soft soil within a model test chamber according to claim 1, characterized in that: The rack and pinion lifting drive mechanism is a hand-cranked drive mechanism, including a hand-cranked drive shaft and a mounting box. The lifting rack is vertically slidably installed in the mounting box, and a main gear is provided in the mounting box. The main gear meshes with the lifting rack. The hand-cranked drive shaft is horizontally arranged, and the front end of the hand-cranked drive shaft meshes with the main gear through a gear set.

6. The method for constructing multi-directional sandy drainage channels in soft soil within a model test chamber according to claim 1, characterized in that: A lifting balancer is also installed at the top of the sandblasting pipe lifting support frame, and the lifting balancer’s pull head is connected to the lifting rack.

7. The method for constructing multi-directional sandy drainage channels in soft soil within a model test chamber according to claim 1, characterized in that: Data acquisition sensors are installed inside the model test chamber.

8. The method for constructing multi-directional sandy drainage channels in soft soil within a model test chamber according to claim 7, characterized in that: The data acquisition sensors include: pressure sensors, displacement sensors, pore water pressure sensors, and water content sensors.

9. The method for constructing multi-directional sandy drainage channels in soft soil within a model test chamber according to claim 1, characterized in that, Includes the following steps: Step 1: Install a vertical nozzle at the bottom outlet of the sandblasting pipe; Step 2: Drive the lifting rack down, so that the lifting rack carries the sandblasting pipe into the soft soil of the model test box, and insert the vertical nozzle at the bottom of the sandblasting pipe into the set depth. Step 3: Turn on the sandblasting machine and simultaneously drive the lifting rack to rise, which will move the vertical nozzle upward and form a vertical sandy drainage channel in the soft soil of the model test box. When the vertical nozzle rises to the middle position of the model test box, turn off the sandblasting machine and stop the movement of the lifting rack. Record the depth of the vertical nozzle at this time. Step 4: Drive the lifting rack to continue rising, raise the vertical nozzle out of the model test box, then replace the L-shaped nozzle, and drive the lifting rack down again to the depth position recorded in Step 3. Then turn on the sandblasting machine, lay out a horizontal sand drainage channel, and turn off the sandblasting machine after the channel is formed. Step 5: Drive the lifting rack upwards to raise the L-shaped nozzle out of the model test box. Then replace the vertical nozzle and drive the lifting rack downwards again to the depth position of the horizontal sandy drainage channel constructed in the previous step. Then turn on the sandblasting machine and drive the lifting rack upwards at the same time to move the vertical nozzle upwards. Continue to construct a section of vertical sandy drainage channel in the soft soil. When the vertical nozzle rises to the set height position, turn off the sandblasting machine and stop the movement of the lifting rack. Record the depth of the vertical nozzle at this time. Step 6: Drive the lifting rack to continue rising, raise the vertical nozzle out of the model test chamber, then replace the L-shaped nozzle, and drive the lifting rack down again to the depth position recorded in Step 5, and drive the rotating base to adjust the rotation angle of the model test chamber; then turn on the sandblasting machine, lay out a new transverse sand drainage channel with a different direction from the previous transverse sand drainage channel, and turn off the sandblasting machine after forming the channel. Step 7: Repeat steps 5 and 6 to continue constructing vertical sandy drainage channels and horizontal sandy drainage channels in different directions in the soft soil until the last section of the vertical sandy drainage channel extends out of the soft soil surface.

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