A method for observing the water vapor state inside an indoor heating drainage pipe

Abstract

This invention discloses a method for observing the water vapor state inside an indoor heating drainage pipe. The method includes: introducing soil into a model box equipped with a drainage pipe; placing a resistance heating rod and a temperature sensor in the soil; placing a pore water pressure sensor in the soil inside the model box; placing a camera inside the inner tube of the drainage pipe; sequentially laying a medium-coarse sand layer and a sealing membrane on the top of the model box; sealing the gaps at the base of the model box with sealant; using a vacuum device to create a vacuum, allowing pore water in the soil inside the model box to pass through a filter membrane into a toothed plate and then upwards along the toothed plate to the medium-coarse sand layer; the pore water in the soil then enters a jet pump and is discharged through a membrane exit device on the sealing membrane; simultaneously heating the soil inside the model box using the resistance heating rod; monitoring the temperature of the soil inside the model box and the dissipation of pore water using the temperature sensor and pore water pressure sensor; and photographing the water vapor state inside the pipe to determine whether it is in liquid or gaseous form.

Description

Technical Field

[0001] This invention relates to the field of vacuum preloading foundation treatment technology using heating methods, and in particular to a method for observing the water vapor state inside an indoor heated drainage pipe. Background Technology

[0002] In recent years, heated vacuum preloading has emerged as a new development direction in vacuum preloading, but research is still in its early stages. Currently, most heated vacuum preloading research is theoretical, with only a few scholars conducting experimental studies, and the reinforcement effect differs somewhat from theoretical research. Increasing the temperature of cohesive soil can effectively increase its permeability coefficient. Simultaneously, under negative pressure, the boiling point of water gradually decreases; at a vacuum negative pressure of -85 kPa, the boiling point of water is 52℃. Whether the water entering the drainage pipe during vacuum preloading exists in liquid or gaseous form is still undetermined. Similarly, when the foundation soil is heated to 52℃ under a vacuum negative pressure of -85 kPa, whether the water inside the drainage pipe exists in liquid or gaseous form is also undetermined.

[0003] Current technology suggests that during vacuum preloading, the vacuum level inside the drain pipe decreases along the depth direction. However, when using heated vacuum preloading, if the water in the drain pipe is mostly in gaseous form, the vacuum level will not decrease along the depth direction, which will have a significant impact on the calculation theory of heated vacuum preloading. Summary of the Invention

[0004] The purpose of this application is to provide a method for observing the water vapor state inside an indoor heating drainage pipe, in order to address the technical deficiencies existing in the prior art.

[0005] The technical solution adopted to achieve the purpose of this application is:

[0006] A method for observing the water vapor state inside an indoor heating drainage pipe, the observation device including a model bucket containing soil and a vacuum pumping device; the model bucket is connected to the vacuum pumping device for evacuating the model bucket.

[0007] The base of the model barrel is equipped with a toothed drainage pipe to drain pore water from the soil inside the barrel. Multiple cameras are fixedly installed at equal intervals along the depth of the drainage pipe to capture the water vapor state within it. Four resistance heating rods and multiple temperature sensors are horizontally arranged within the soil of the model barrel. The resistance heating rods heat the soil, and the temperature sensors monitor its temperature. Multiple pore water pressure sensors are vertically arranged within the soil to monitor the dissipation of pore water pressure during vacuum heating and pre-compression of the soil. A medium-coarse sand layer is laid on top of the model barrel to facilitate the drainage of pore water from the drainage pipe. A sealing membrane is laid above the medium-coarse sand layer to seal the observation device. An outlet device is installed on the sealing membrane to drain water from the medium-coarse sand layer.

[0008] The observation method includes the following steps:

[0009] Step 1: Fill the model barrel with a toothed drainage pipe at the base with soil, and place four resistance heating rods and multiple temperature sensors horizontally in the soil inside the model barrel, and place multiple pore water pressure sensors vertically in the soil inside the model barrel.

[0010] Step 2: Install multiple cameras at equal intervals along the depth of the drain pipe inside the drain pipe. Then, lay a layer of medium-coarse sand on top of the model barrel, then lay a sealing film on top of the medium-coarse sand layer, and seal the gaps at the base of the model barrel with sealant.

[0011] Step 3: Use a vacuum pump to evacuate the model barrel, so that the pore water in the soil inside the model barrel enters the toothed plate through the filter membrane of the drainage pipe, and is discharged upward along the toothed plate to the medium-coarse sand layer. Utilize the drainage properties of the medium-coarse sand layer to allow the pore water in the soil inside the medium-coarse sand layer to enter the jet pump through the membrane outlet device on the sealing membrane, and be discharged through the jet pump.

[0012] Step 4: While evacuating the model barrel, a resistance heating rod is used to heat the soil inside the model barrel. Temperature sensors and pore water pressure sensors are used to monitor the temperature of the soil inside the model barrel and the dissipation of pore water pressure. A camera in the inner tube is used to photograph the water vapor state inside the inner tube, and the water inside the inner tube is determined to be in liquid or gaseous form based on the images taken by the camera.

[0013] In the above technical solution, the drainage pipe includes an inner pipe, and a toothed plate is provided on the outer side of the inner pipe along the circumferential direction, which is used to discharge the pore water of the soil in the model bucket upward along the toothed plate to the medium and coarse sand layer, forming a vertical drainage channel; the outer side of the toothed plate includes a filter membrane, which is used to filter the pore water entering the toothed plate.

[0014] In the above technical solution, the inner tube is a transparent plastic tube, which enables the camera inside the drain pipe to take high-definition pictures of the water vapor state inside the toothed plate.

[0015] In the above technical solution, the camera is a high-speed industrial camera.

[0016] In the above technical solution, the temperature sensor is a probe-type high-temperature platinum resistance thermometer.

[0017] In the above technical solution, the pore water pressure sensor is a string sensor.

[0018] In the above technical solution, one end of the membrane discharge device on the sealing membrane is connected to the medium-coarse sand layer, and the other end is connected to a jet pump for conveying the discharged soil pore water.

[0019] In the above technical solution, there is a gap on the base of the model barrel, which is sealed with sealant.

[0020] In the above technical solution, the wall thickness of the model barrel is 10mm to prevent deformation during the entire experiment.

[0021] The beneficial effects of this invention are as follows:

[0022] 1. The observation method of the present invention, through an integrally molded hollow plastic drainage pipe with toothed plate, can realize the function of vertical drainage of pore water in the soil outside the pipe along the toothed plate; a high-speed industrial camera placed inside the pipe can capture the water vapor state inside the toothed plate in high definition, and observe the existence state of water vapor inside the drainage pipe during the heating and vacuum pre-compression process.

[0023] 2. The pore water pressure sensor of the present invention can effectively monitor the dissipation of pore water in the foundation soil during the heating vacuum preloading process; the temperature sensor can automatically monitor the temperature of the reinforced soil and reasonably control temperature changes.

[0024] 3. The principle and design concept of the observation device for the water vapor state in the indoor heating drainage pipe of the present invention are clear. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the observation device structure of the present invention.

[0027] Figure 2This is a schematic diagram of the cross-sectional structure of the drainage pipe of the present invention.

[0028] In the diagram: 1-Model barrel, 2-Drainage pipe with toothed plate, 2-1-Inner pipe, 2-2-Toothed plate, 2-3-Filter membrane, 3-Camera, 4-Pore water pressure sensor, 5-Temperature sensor, 6-Sealing membrane, 7-Resistance heating rod, 8-Vacuum pump, 9-Medium-coarse sand layer. Detailed Implementation

[0029] 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.

[0030] See Figure 1 An observation device for the water vapor state inside an indoor heating drainage pipe includes a model barrel 1 containing soil (the soil can be silt or riverbed mud) and a vacuum pumping device 8; the model barrel 1 is connected to the vacuum pumping device 8 for evacuating the model barrel 1.

[0031] The base of the model barrel 1 is equipped with a drainage pipe 2 with a toothed plate to drain pore water from the soil inside the model barrel 1; see also Figure 2The drainage pipe 2 includes an inner pipe 2-1. A toothed plate 2-2 is arranged circumferentially on the outer side of the inner pipe 2-1 to allow pore water in the soil of the model bucket 1 to drain upwards along the toothed plate 2-2 to the medium-coarse sand layer 9, forming a vertical drainage channel. A filter membrane 2-3 is included on the outer side of the toothed plate 2-2 to filter the pore water entering the toothed plate 2-2. Multiple cameras 3 are fixedly installed at equal intervals along the depth of the drainage pipe 2 to capture the water and air conditions inside the drainage pipe 2. The inner pipe 2-1 is a transparent plastic pipe, allowing the cameras inside the drainage pipe 2 to capture high-definition images of the water and air conditions inside the toothed plate 2-2. The cameras 3 are high-speed industrial cameras capable of automatic focusing and capturing images of the water and air conditions inside the inner pipe 2-1 of the drainage pipe 2. Four resistance heating rods 7 and multiple temperature sensors 5 are horizontally arranged within the soil of the model barrel 1. The resistance heating rods 7 heat the soil within the model barrel 1, and the temperature sensors 5 monitor the soil temperature. The temperature sensors 5 are probe-type high-temperature platinum resistance thermometers, which utilize the characteristic of platinum material's resistance changing with temperature to measure the soil temperature within the model barrel 1. Multiple pore water pressure sensors 4 are vertically arranged within the soil of the model barrel 1 to monitor the dissipation of pore water pressure during the vacuum heating and pre-compression process. The pore water pressure sensors 4 are string sensors, which are small in size and highly sensitive. A medium-coarse sand layer 9 is laid on top of the model barrel 1 to facilitate the drainage of pore water from the drainage pipe 2. A sealing membrane 6 is laid above the medium-coarse sand layer 9 to seal the observation device. The sealing membrane 6 is equipped with a membrane discharge device to drain the water from the medium-coarse sand layer 9. One end of the membrane discharge device on the sealing membrane 6 is connected to the medium-coarse sand layer 9, and the other end is connected to a jet pump for conveying the discharged soil pore water.

[0032] There is a gap on the base of the model barrel 1, which is sealed with sealant.

[0033] Furthermore, the wall thickness of the model barrel 1 is 10mm, which can prevent deformation during the entire experiment.

[0034] A method for observing the water vapor state inside an indoor heating drainage pipe includes the following steps:

[0035] Step 1: Fill the model bucket 1, which has a drainage pipe 2 with a toothed plate on the base, with soil. Then, place four resistance heating rods 7 and multiple temperature sensors 5 horizontally in the soil inside the model bucket, and place multiple pore water pressure sensors 4 vertically in the soil inside the model bucket.

[0036] Step 2: Install multiple cameras 3 at equal intervals along the depth of the drain pipe 2 in the inner pipe 2-1 of the drain pipe 2. Then, lay a medium-coarse sand layer 9 on the top of the model barrel, lay a sealing film 6 on top of the medium-coarse sand layer 9, and seal the gaps at the base of the model barrel 1 with sealant.

[0037] Step 3: Vacuum the model barrel 1 using the vacuum device 8, so that the pore water in the soil inside the model barrel 1 enters the toothed plate 2-2 through the filter membrane 2-3 of the drainage pipe 2, and is discharged upward along the toothed plate 2-2 to the medium-coarse sand layer 9. Utilizing the drainage properties of the medium-coarse sand layer 9, the water in the medium-coarse sand layer 9 enters the jet pump through the membrane outlet device on the sealing membrane 6, and is discharged through the jet pump.

[0038] Step 4: While evacuating the model barrel 1, the soil inside the model barrel 1 is heated using the resistance heating rod 7. The temperature of the soil inside the model barrel 1 and the dissipation of the pore water pressure are monitored by the temperature sensor 5 and the pore water pressure sensor 4. The water vapor state inside the inner tube 2-1 is photographed by the camera 3 in the inner tube 2-1. The water inside the inner tube 2-1 is determined to be in liquid or gaseous form based on the images taken by the camera 3.

[0039] The above description is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for observing the water vapor state inside an indoor heating drainage pipe, characterized in that, The observation device includes a model bucket containing soil and a vacuum pumping device; the model bucket is connected to the vacuum pumping device for evacuating the model bucket. The base of the model barrel is equipped with a toothed drainage pipe to drain pore water from the soil inside the barrel. Multiple cameras are fixedly installed at equal intervals along the depth of the drainage pipe to capture the water vapor state within it. Four resistance heating rods and multiple temperature sensors are horizontally arranged within the soil of the model barrel. The resistance heating rods heat the soil, and the temperature sensors monitor its temperature. Multiple pore water pressure sensors are vertically arranged within the soil to monitor the dissipation of pore water pressure during vacuum heating and pre-compression of the soil. A medium-coarse sand layer is laid on top of the model barrel to facilitate the drainage of pore water from the drainage pipe. A sealing membrane is laid above the medium-coarse sand layer to seal the observation device. An outlet device is installed on the sealing membrane to drain water from the medium-coarse sand layer. The observation method includes the following steps: Step 1: Fill the model barrel with a toothed drainage pipe at the base with soil, and place four resistance heating rods and multiple temperature sensors horizontally in the soil inside the model barrel, and place multiple pore water pressure sensors vertically in the soil inside the model barrel. Step 2: Install multiple cameras at equal intervals along the depth of the drain pipe inside the drain pipe. Then, lay a layer of medium-coarse sand on top of the model barrel, then lay a sealing film on top of the medium-coarse sand layer, and seal the gaps at the base of the model barrel with sealant. Step 3: Use a vacuum pump to evacuate the model barrel, so that the pore water in the soil inside the model barrel enters the toothed plate through the filter membrane of the drainage pipe, and is discharged upward along the toothed plate to the medium-coarse sand layer. Utilize the drainage properties of the medium-coarse sand layer to allow the water in the medium-coarse sand layer to enter the jet pump through the membrane outlet device on the sealing membrane, and be discharged through the jet pump. Step 4: While evacuating the model barrel, a resistance heating rod is used to heat the soil inside the model barrel. Temperature sensors and pore water pressure sensors are used to monitor the temperature of the soil inside the model barrel and the dissipation of pore water pressure. A camera in the inner tube is used to photograph the water vapor state inside the inner tube, and the water inside the inner tube is determined to be in liquid or gaseous form based on the images taken by the camera.

2. The observation method according to claim 1, characterized in that, The drainage pipe includes an inner pipe, and a toothed plate is provided on the outer side of the inner pipe along the circumferential direction to allow pore water in the soil inside the model bucket to be discharged upward along the toothed plate to the medium-coarse sand layer, forming a vertical drainage channel; the outer side of the toothed plate includes a filter membrane for filtering the pore water entering the toothed plate.

3. The observation method according to claim 2, characterized in that, The inner tube is a transparent plastic tube, which allows the camera inside the drain pipe to take high-definition pictures of the water vapor state inside the toothed plate.

4. The observation method according to claim 1, characterized in that, The camera is a high-speed industrial camera.

5. The observation method according to claim 1, characterized in that, The temperature sensor is a probe-type high-temperature platinum resistance thermometer.

6. The observation method according to claim 1, characterized in that, The pore water pressure sensor is a string sensor.

7. The observation method according to claim 1, characterized in that, One end of the membrane discharge device on the sealing membrane is connected to the medium-coarse sand layer, and the other end is connected to a jet pump for conveying the discharged soil pore water.

8. The observation method according to claim 1, characterized in that, There are gaps on the base of the model barrel, which are sealed with sealant.

9. The observation method according to claim 1, characterized in that, The model barrel has a wall thickness of 10mm to prevent deformation during the experiment.

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