Local pressure drop monitoring device for vacuum preloading site

Abstract

The local pressure drop monitoring device for the vacuum preloading site comprises a control wheel and a valve which are oppositely arranged, wherein a pressure difference detection module is arranged between the control wheel and the valve; the pressure difference detection module comprises an air duct; the air duct comprises a straight section, a contraction section and an expansion section which are connected in sequence, and air speed sensors are arranged on the inner walls of the straight section and the expansion section respectively; a fan is mounted in the middle of the control wheel; the valve comprises a valve body, a plurality of fan-shaped plates are arranged in the middle of the valve body, and the fan-shaped plates are matched with the valve body to form a sliding pair. A set of protrusions are arranged on the peripheral face of the valve body at intervals in the circumferential direction, a set of transmission columns are arranged on the control wheel at intervals in the circumferential direction, and the transmission columns are inserted into gaps between every two adjacent protrusions and matched with the protrusions to form gear transmission. When in use, the monitoring device is installed at a reserved access hole in a site, pressure difference monitoring is carried out on an area where pressure drop is prone to occurring in the site, and then whether follow-up pressure supplement needs to be carried out or not is judged according to the measured actual pressure drop amplitude.

Description

Technical Field

[0001] The utility model relates to the technical field of soft soil foundation reinforcement, in particular to a local pressure drop monitoring device for a vacuum preloading site. Background Art

[0002] Due to the high compressibility and low bearing capacity of soft soil, the soft soil foundation has the characteristics of large porosity, high water content, and large settlement. In order to carry out building structures and construction on the soft soil foundation, the soft soil foundation needs to be reinforced. Traditional reinforcement technologies include filling, replacement, chemical grouting, etc.; although these technologies can effectively reinforce the soft soil foundation, they are often costly and have a long construction period.

[0003] As an alternative method, vacuum preloading technology has the advantages of short construction period, low cost, and significant drainage effect. It has been widely used in large and environmentally sensitive areas, such as swamps, landfills, and industrial wastelands. Vacuum preloading technology is to lay a permeable layer and a vacuum membrane on the surface of soft soil, and use a vacuum pump to extract air and moisture under the surface to form a negative pressure, thereby accelerating the consolidation of the soil and improving its bearing capacity. However, in the prior art, this reinforcement method still has the following defects and shortcomings: the adjustment ability is limited. When the vacuum system is installed and starts to operate, it becomes very difficult to adjust the pressure field that has been formed, especially in local areas such as the corners of the site. It is very easy to leak and cause a pressure drop, but it cannot be monitored, thus affecting the reinforcement effect. Utility Model Content

[0004] The present application provides a local pressure drop monitoring device for a vacuum preloading site to overcome the above-mentioned problems existing in the prior art. The local pressure drop monitoring device for a vacuum preloading site of the present application is installed at the inspection port reserved in the site when in use, and monitors the pressure difference in the area where pressure drop is prone to occur in the site, and then judges whether adjustment (such as subsequent pressure replenishment) is required according to the actual pressure drop range, thereby achieving precise control of the pressure difference between the soft soil pressure under the vacuum membrane and the atmospheric pressure; and the monitoring device of the present application is small and light in size, and can be easily moved between various inspection ports in the site, which is convenient for rapid deployment and high flexibility in use. In addition, compared with the overall pressure control in the site, targeted monitoring of the key inspection port locations where pressure is prone to drop in the site, and judging the adjustment strategy according to the actual pressure drop situation can save costs as much as possible while ensuring the construction effect.

[0005] The technical solution of this application is:

[0006] A local pressure drop monitoring device for a vacuum preloading site comprises a control wheel and a valve which are arranged opposite to each other; the control wheel is annular and a fan is installed in the middle; a pressure difference detection module is arranged between the control wheel and the valve; the pressure difference detection module comprises a wind tube; the wind tube comprises a straight section, a contraction section and an expansion section which are connected in sequence; wind speed sensors are respectively arranged on the inner walls of the straight section and the expansion section; the valve comprises a valve body which is used to be connected to an inspection port in the site; a plurality of fan-shaped plates are arranged in the middle of the valve body, and the fan-shaped plates cooperate with the valve body to form a sliding pair; when the valve is closed, the top angle of each fan-shaped plate is located at the same center of a circle; a group of protrusions are arranged at intervals along the circumferential direction on the outer peripheral surface of the valve body, and correspondingly, a group of transmission columns are arranged at intervals along the circumferential direction on the control wheel; the transmission column is inserted into the gap between two adjacent protrusions and cooperates with the protrusion to form a gear transmission.

[0007] Compared with the prior art, the local pressure drop monitoring device for vacuum preloading sites of the present application includes a control wheel, a valve, a fan and a pressure difference detection module; when in use, the valve is installed at the inspection port reserved in the area where pressure drop is prone to occur, and the rotation of the fan is used to monitor whether there is gas flow at the inspection port position. If there is gas flow, the control wheel is further used to briefly open the valve, and the pressure difference detection module measures the pressure difference of the current inspection port to determine whether adjustment is required (for example, whether subsequent pressure replenishment is required), thereby achieving precise control of the pressure difference between the soft soil pressure under the vacuum membrane and the atmospheric pressure; the monitoring device of the present application adopts the above structure, with a small and light size, and can be easily moved between various inspection ports in the site, which is convenient for rapid deployment and has high flexibility in use. In addition, compared with the overall pressure control in the site, targeted monitoring of the key inspection port positions where the pressure is prone to drop in the site is carried out, and the adjustment strategy is determined according to the actual pressure drop situation, which can save costs as much as possible while ensuring the construction effect.

[0008] As an optimization, in the aforementioned vacuum preloading site local pressure drop monitoring device, further, the inclination angles of the expansion section and the contraction section can be 12° to 18°.

[0009] As an optimization, in the aforementioned local pressure drop monitoring device for vacuum preloading sites, the valve body includes an inner sleeve and an outer sleeve; the protrusion is provided on the outer sleeve; a group of inclined connecting rods are provided between the inner sleeve and the outer sleeve along the circumferential interval; the inclined connecting rod is provided with an elongated hole, and correspondingly, the fan-shaped plate is provided with a sliding shaft, and the sliding shaft cooperates with the elongated hole and can slide in the elongated hole. The valve body adopts the above-mentioned structure, which is easy to manufacture and easy to assemble. When in use, it is only necessary to rotate the outer sleeve to drive the sliding shaft to slide in the elongated hole, so that the fan-shaped plate is dispersed or closed, thereby realizing the opening or closing of the valve, which is relatively simple to implement. Furthermore, the inner sleeve is connected to the inspection port by a thread. At this time, the connection structure is simple and easy to install.

[0010] As an optimization, in the aforementioned vacuum preloading site local pressure drop monitoring device, a wind speed sensor is provided on both sides of the inner wall of the expansion section and the straight section. When in use, the gas flow rate in the expansion section and the straight section is respectively monitored in real time by the two wind speed sensors, and the pressure difference is calculated after taking the average value, with high measurement accuracy.

[0011] As an optimization, in the aforementioned vacuum preloading site local pressure drop monitoring device, the straight section is fixed to the valve body by threaded connection. In this case, the connection structure is simple and easy to install.

[0012] As an optimization, in the aforementioned vacuum preloading site local pressure drop monitoring device, the control wheel and the transmission column are integrally formed. In this case, the structure is simple and easy to manufacture.

[0013] As an optimization, in the aforementioned vacuum preloading site local pressure drop monitoring device, the fan is connected to the control wheel through a connecting rod. In this case, the assembly is convenient and easy to implement. Furthermore, the fan is provided with 4 blades, and the blades are made of plastic. Plastic material has the advantages of durability, waterproofness, and light weight; the blades are made of plastic material, the overall weight is light, it is easier to rotate when in use, it has high sensitivity, good reliability, and low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of a local pressure drop monitoring device for a vacuum preloading site of the present application;

[0015] Figure 2 It is a schematic diagram of the assembly of the control wheel, fan, and transmission column in this application;

[0016] Figure 3 It is a structural schematic diagram of the valve body in this application;

[0017] Figure 4 It is a schematic diagram of the structure of the fan-shaped plate in this application;

[0018] Figure 5 It is a schematic diagram of the valve in this application when it is closed;

[0019] Figure 6 It is a schematic diagram of the valve in this application when it is open;

[0020] Figure 7 It is a schematic diagram of the structure of the air duct in this application;

[0021] Figure 8 It is a structural diagram of the pressure difference detection module in this application.

[0022] The markings in the accompanying drawings are: 1-control wheel; 2-valve, 21-valve body, 211-inner sleeve, 212-outer sleeve, 213-inclined connecting rod, 2131-long hole, 22-fan plate, 221-sliding shaft, 23-protrusion; 3-fan; 4-wind cylinder, 41-straight section, 42-contraction section, 43-expansion section; 5-wind speed sensor; 6-transmission column; 7-connecting rod. DETAILED DESCRIPTION

[0023] The present application is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present application.

[0024] See also Figures 1 to 8 The local pressure drop monitoring device of the vacuum preloading site of the present application comprises a control wheel 1 and a valve 2 which are arranged opposite to each other; the control wheel 1 is annular and a fan 3 is installed in the middle; a pressure difference detection module is arranged between the control wheel 1 and the valve 2; the pressure difference detection module comprises a wind tube 4 (the wind tube 4 has openings at both ends); the wind tube 4 comprises a straight section 41, a contraction section 42 and an expansion section 43 which are connected in sequence; the contraction section 42 is inclined inwardly, and the expansion section 43 is inclined outwardly; the inner walls of the straight section 41 and the expansion section 43 are respectively provided with wind speed sensors. Sensor 5; the valve 2 includes a valve body 21, which is used to connect with the inspection port in the site; a plurality of fan-shaped plates 22 are provided in the middle of the valve body 21, and the fan-shaped plates 22 cooperate with the valve body 21 to form a sliding pair; when the valve 2 is closed, the vertex angle of each fan-shaped plate 22 is located at the same center of a circle; a group of protrusions 23 are provided on the outer peripheral surface of the valve body 21 at intervals along the circumferential direction, and correspondingly, a group of transmission columns 6 are provided on the control wheel 1 at intervals along the circumferential direction; the transmission column 6 is inserted into the gap between two adjacent protrusions 23, and cooperates with the protrusions 23 to form a gear transmission.

[0025] Example:

[0026] See also Figure 8 In this embodiment, the inclination angle α of the expansion section 43 and the inclination angle β of the contraction section 42 are both 15°.

[0027] See also Figures 3 to 5In this embodiment, the valve body 21 includes an inner sleeve 211 and an outer sleeve 212; the protrusion 23 is arranged on the outer sleeve 212; a group of inclined connecting rods 213 are arranged between the inner sleeve 211 and the outer sleeve 212 along the circumferential direction; the inclined connecting rod 213 is provided with an elongated hole 2131, and correspondingly, the fan-shaped plate 22 is provided with a sliding shaft 221, and the sliding shaft 221 cooperates with the elongated hole 2131 and can slide in the elongated hole 2131. The valve body 21 adopts the above structure, which is convenient to manufacture and easy to assemble. When in use, it is only necessary to rotate the outer sleeve 212 to drive the sliding shaft 221 to slide in the elongated hole 2131, so that the fan-shaped plate 22 is dispersed or closed, thereby realizing the opening or closing of the valve 2 (when the valve is closed, multiple fan-shaped plates 22 are spliced ​​into a circle, which just blocks the opening on the inner sleeve 211), which is relatively simple to implement. Further, the inner sleeve 211 is connected to the inspection port by thread. In this case, the connection structure is simple and easy to install. The outer peripheral wall of the inspection port is provided with an external thread, and correspondingly, the inner peripheral wall of the inner sleeve 211 is provided with an internal thread.

[0028] In this embodiment, a wind speed sensor 5 is provided on both sides of the inner wall of the expansion section 43 and the straight section 41. When in use, the gas flow rate in the expansion section 43 and the straight section 41 is respectively monitored in real time by the two wind speed sensors 5, and the pressure difference is calculated after taking the average value, with high measurement accuracy.

[0029] In this embodiment, the straight section 41 is fixed to the valve body 21 by threaded connection. In this case, the connection structure is simple and easy to install. The outer peripheral wall of the straight section 41 is provided with an external thread, and correspondingly, the inner peripheral wall of the valve 21 is provided with an internal thread.

[0030] See also Figure 2 In this embodiment, the control wheel 1 and the transmission column 6 are integrally cast from stainless steel (they can also be connected by welding). At this time, the structure is simple and easy to manufacture. Furthermore, the fan 3 is connected to the control wheel 1 through a connecting rod 7. At this time, the assembly is convenient and easy to implement. Furthermore, the fan 3 is provided with 4 blades, and the blades are made of plastic. Plastic material has the advantages of durability, waterproofness and light weight; the blades are made of plastic material, the overall weight is light, it is easier to rotate during use, the reliability is high, and the manufacturing cost is low. The central rotating shaft and the external frame of the fan 3 are made of stainless steel.

[0031] In this embodiment, eight protrusions 23 are evenly spaced along the circumferential direction on the outer circumferential surface of the valve body 21, and correspondingly, eight transmission columns 6 are evenly spaced along the circumferential direction on the control wheel 1. Six inclined connecting rods 213 are evenly spaced along the circumferential direction between the inner sleeve 211 and the outer sleeve 21, and correspondingly, the number of the sector plates 22 is six.

[0032] In this embodiment, the outer diameter of the control wheel 1 is 30 cm and the inner diameter is 20 cm; the inner diameter of the inner sleeve 211 is 10 cm; the diameter of the fan 3 is 15 cm and the thickness is 5 cm; the heights of the straight section 41, the contraction section 42 and the expansion section 43 of the wind tube 4 are all 5 cm.

[0033] The monitoring principle is as follows:

[0034] (1) The monitoring device of the present application is installed at the local inspection port to be inspected, and the inner sleeve 211 is connected to the inspection port by threads; in the initial state, the six fan-shaped plates 22 are spliced ​​into a circle, that is, the top corners of the fan-shaped plates 22 are located at the same center, and the center is coaxial with the center of the inner sleeve 211. The fan-shaped plates 22 block the opening of the inner sleeve 211, and the valve 2 is closed.

[0035] (2) In the absence of wind, observe whether the blades of fan 2 rotate continuously for more than 30 seconds within 10 minutes: a. If no rotation is observed, it means that the pressure of this inspection port is normal, and the monitoring device is moved to the next local inspection port for detection; b. If continuous rotation is observed for more than 30 seconds, it means that the position of this inspection port has become abnormal; turn the control wheel 1 to make the transmission column 6 cooperate with the protrusion 23 on the valve 2 to form a gear transmission, driving the valve body 21 to rotate (at this time, the inner sleeve 211 will rotate relative to the inspection port; the threaded connection section between the inner sleeve 211 and the inspection port needs to be designed to be relatively long), driving the six fan-shaped plates 22 to disperse outward, and the valve 2 opens (such as Figure 6 Let the valve 2 open for 10 seconds and record the data of the wind speed sensor 5 during these 10 seconds; then rotate the control wheel 1 in the reverse direction to close the valve 2.

[0036] (3) Based on the average value of the gas flow rate of the expansion section 43 and the straight section 41, the pressure difference on both sides of the valve 2 is calculated to determine whether the pressure difference at this time is lower than 90% of the designed vacuum preload pressure; if it is lower than this value, subsequent pressure replenishment is required; if it is not lower than this value, the monitoring device is moved to the next local inspection port for inspection.

[0037] The above general description of the utility model involved in this application and the description of its specific implementation method should not be understood as limiting the technical solution of the utility model. Based on the disclosure of this application, those skilled in the art can add, reduce or combine the disclosed technical features in the above general description or / and the specific implementation method (including examples) without violating the constituent elements of the utility model involved, to form other technical solutions within the scope of protection of this application.

Claims

1. A local pressure drop monitoring device for vacuum preloading sites, characterized in that: The invention comprises a control wheel (1) and a valve (2) which are arranged opposite to each other; the control wheel (1) is annular and has a fan (3) installed in the middle; a pressure difference detection module is arranged between the control wheel (1) and the valve (2); the pressure difference detection module comprises a wind tube (4); the wind tube (4) comprises a straight section (41), a contraction section (42) and an expansion section (43) which are connected in sequence; wind speed sensors (5) are respectively arranged on the inner walls of the straight section (41) and the expansion section (43); the valve (2) comprises a valve body (21) for communicating with the air inside the venue; The valve body (21) is connected to an inspection port; a plurality of sector plates (22) are provided in the middle of the valve body (21), and the sector plates (22) cooperate with the valve body (21) to form a sliding pair; when the valve (2) is closed, the top angle of each sector plate (22) is located at the same center of a circle; a group of protrusions (23) are provided at intervals along the circumferential direction on the valve body (21), and correspondingly, a group of transmission columns (6) are provided at intervals along the circumferential direction on the control wheel (1); the transmission column (6) is inserted into the gap between two adjacent protrusions (23) and cooperates with the protrusions (23) to form a gear transmission.

2. The local pressure drop monitoring device for vacuum preloading site according to claim 1 is characterized in that: The inclination angles of the expansion section (43) and the contraction section (42) are between 12° and 18°.

3. The local pressure drop monitoring device for vacuum preloading site according to claim 1 is characterized in that: The valve body (21) comprises an inner sleeve (211) and an outer sleeve (212); the protrusion (23) is arranged on the outer peripheral surface of the outer sleeve (212); a group of inclined connecting rods (213) are arranged between the inner sleeve (211) and the outer sleeve (212) at intervals along the circumferential direction; the inclined connecting rods (213) are provided with elongated holes (2131), and correspondingly, the fan-shaped plate (22) is provided with a sliding shaft (221), and the sliding shaft (221) cooperates with the elongated holes (2131) and can slide in the elongated holes (2131).

4. The local pressure drop monitoring device for vacuum preloading site according to claim 3 is characterized in that: The inner sleeve (211) is connected to the inspection port via threads.

5. The local pressure drop monitoring device for vacuum preloading site according to claim 1 is characterized in that: A wind speed sensor (5) is provided on both sides of the inner wall of the expansion section (43) and the straight section (41), respectively.

6. The local pressure drop monitoring device for vacuum preloading site according to claim 1 is characterized in that: The straight section (41) is fixed to the valve body (21) via threaded connection.

7. The local pressure drop monitoring device for vacuum preloading site according to claim 1 is characterized in that: The control wheel (1) and the transmission column (6) are integrally formed.

8. The local pressure drop monitoring device for vacuum preloading site according to claim 1 is characterized in that: The fan (3) is connected to the control wheel (1) via a connecting rod (7).

9. The local pressure drop monitoring device for vacuum preloading site according to claim 8, characterized in that: The fan (3) is provided with four fan blades, and the fan blades are made of plastic.

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