DEVICES USED IN LABORATORIES TO MEASURE HORIZONTAL DISPLACEMENT OF SOIL AROUND A FOUNDATION TO BE TREATED BY VACUUM PRELOADING, AND MEASUREMENT METHODS

• US 20180282966A1
• Filed: 09/22/2017
• Published: 10/04/2018
• Est. Priority Date: 03/30/2017
• Status: Active Grant

• Current Assignee: Wenzhou University
• Original Assignee: Wenzhou University
• Inventors: WANG, JUN, CAI, YUANQIANG, FU, HONGTAO, SHI, CHANGXIN, WANG, PENG, NI, JUNFENG, FANG, ZIQUAN
• Granted Patent: US 10,472,788 B2
• Time in Patent Office: Days
• CPC Class Codes: E02D 2250/0053 using suction or vacuum techniques
• CPC Class Codes: E02D 2600/10 comprising sensor means
• CPC Class Codes: E02D 2600/20 comprising details of connection between elements
• CPC Class Codes: E02D 3/10 by watering, draining, de-aerating or blasting, e.g. by installing sand or wick drains E02D3/11 takes precedence; soil-penetrating vibrators with auxiliary watering E02D3/054; drainage of soil in general E02B11/00
• CPC Class Codes: G01N 33/24 Earth materials G01N33/42 takes precedence

Abstract

The present invention discloses a device used in laboratories to measure horizontal displacement of soil around a region to be treated by vacuum preloading, comprising a box; dredger fill is injected into the box; a vertical drainage board and a vacuum pumping tube are buried within soil in the region to be treated, with the vacuum pumping tube being provided with a vacuum degree detector, the vacuum pumping tube being connected to the plastic drainage board and to a vacuum pump, and a seal membrane covering or wrapping soil in the region to be treated; a loading device is provided above the seal membrane to assist the drainage; transverse tubes are inserted into a side of the box, the transverse tubes being in surrounding soil of the region to be treated; an annular sensing source which is movable along the transverse tubes together with soil is sleeved on the transverse tubes; each of the transverse tubes is provided with a sensing instrument, and the sensing instrument is connected with a sensor which can be inserted into the transverse tube; when the sensor reaches the sensing source, an alarm signal is sent, and in this way, the different positions of the sensing source at different moments of time are determined. The present invention further provides a measurement method by using the device as described above. By the device used in laboratories to measure horizontal displacement of soil around a region to be treated by vacuum preloading, the amount of displacement of soil around the foundation when treated by vacuum preloading can be accurately obtained.

Claims

1. A device used in laboratories to measure horizontal displacement of soil around a region to be treated by vacuum preloading, comprising a box, characterized in that dredger fill is injected into the box;

a vertical drainage board and a vacuum pumping tube are buried within soil in the region to be treated, with the vacuum pumping tube being provided with a vacuum degree detector, a lower end of the vacuum pumping tube being connected to the plastic drainage board and an upper end thereof being connected to a vacuum pump, and a seal membrane covering or wrapping soil in the region to be treated so that an interior of the seal membrane is kept sealed;

a loading device is provided above the seal membrane to assist the drainage;

transverse tubes are inserted into a side of the box, the transverse tubes being in surrounding soil of the region to be treated;

an annular sensing source which is movable along the transverse tubes together with soil is sleeved on the transverse tubes;

each of the transverse tubes is provided with a sensing instrument, and the sensing instrument is connected with a sensor which can be inserted into the transverse tube;

when the sensor reaches the sensing source, an alarm signal is sent, and in this way, the different positions of the sensing source at different moments of time are determined.

2. The device used in laboratories to measure horizontal displacement of soil around a region to be treated by vacuum preloading according to claim 1, characterized in that a number of transverse tubes are distributed in the height direction of the box.

3. The device used in laboratories to measure horizontal displacement of soil around a region to be treated by vacuum preloading according to claim 1, characterized in that a foot is extended obliquely and outward from the annular sensing source, by which soil drives the annular sensing source to move;

and at least three recesses with a smaller diameter are evenly distributed on an annular body of the annular sensing source, and a roller is sleeved on each of the recesses.

4. The device used in laboratories to measure horizontal displacement of soil around a region to be treated by vacuum preloading according to claim 1, characterized in that the sensing instrument comprises a sensing instrument body on which a telescopic driving device is provided;

each of the transverse tubes is provided with a telescopic rod which is driven by the telescopic driving device;

the sensor is arranged at an end of the telescopic rod;

the telescopic driving device and a sensing device of the sensing instrument are connected to a programmable logic controller which is programmed to send a signal to the telescopic driving device at regular intervals to urge the telescopic driving device to drive the telescopic rod and the sensor to do one telescopic motion forward or backward; and

during the telescopic motion, the programmable logic controller records the position of the annular sensing source whenever sensed by each sensor.

5. The device used in laboratories to measure horizontal displacement of soil around a region to be treated by vacuum preloading according to claim 3, characterized in that the sensing instrument comprises a sensing instrument body on which a telescopic driving device is provided;

each of the transverse tubes is provided with a telescopic rod which is driven by the telescopic driving device;

the sensor is arranged at an end of the telescopic rod;

the telescopic driving device and a sensing device of the sensing instrument are connected to a programmable logic controller which is programmed to send a signal to the telescopic driving device at regular intervals to urge the telescopic driving device to drive the telescopic rod and the sensor to do one telescopic motion forward or backward; and

during the telescopic motion, the programmable logic controller records the position of the annular sensing source whenever sensed by each sensor.

6. The device used in laboratories to measure horizontal displacement of soil around a region to be treated by vacuum preloading according to claim 1, characterized in that the loading device comprises a support;

a hydraulic device is provided on a cross bar of the support;

a chassis is extended downward from the hydraulic device and resisted against the seal membrane to form a positive pressure.

7. The device used in laboratories to measure horizontal displacement of soil around a region to be treated by vacuum preloading according to claim 3, characterized in that the loading device comprises a support;

a hydraulic device is provided on a cross bar of the support;

a chassis is extended downward from the hydraulic device and resisted against the seal membrane to form a positive pressure.

8. The device used in laboratories to measure horizontal displacement of soil around a region to be treated by vacuum preloading according to claim 5, characterized in that the loading device comprises a support;

a hydraulic device is provided on a cross bar of the support;

a chassis is extended downward from the hydraulic device and resisted against the seal membrane to form a positive pressure;

the hydraulic device connects with the programmable logic controller.

9. A method for measuring horizontal displacement of soil around a region to be treated by vacuum preloading, by using the device used in laboratories to measure horizontal displacement of soil around a region to be treated by vacuum preloading according to claim 1, comprising the following steps:

A;

injecting dredger fill into a box of the device for measuring horizontal displacement of soil around a region to be treated by vacuum preloading;

burying a vertical drainage board and a vacuum pumping tube within soil in the region to be treated, with the vacuum pumping tube being provided with a vacuum degree detector, a lower end of the vacuum pumping tube being connected to the plastic drainage board and an upper end thereof being connected to a vacuum pump, and a seal membrane covering or wrapping soil in the region to be treated so that the interior of the seal membrane is kept sealed;

then activating the vacuum pump so that a negative pressure is formed below the seal membrane; and

loading above the seal membrane by using the loading device to form a positive pressure;

B;

inserting the sensor into the transverse tubes at regular intervals and recording the sensed position of the annular sensing source; and

C;

calculating the amount of displacement of the annular sensing source according to the data of the position of the annular sensing source sensed by the sensor, detecting and obtaining the vacuum degree data by using a vacuum degree detector, calculating and loading the data by the loading device, and establishing a test model together with the amount of displacement, the loading force data, the vacuum degree data and the time span.

10. The device used in laboratories to measure horizontal displacement of soil around a region to be treated by vacuum preloading according to claim 2, characterized in that a foot is extended obliquely and outward from the annular sensing source, by which soil drives the annular sensing source to move;

and at least three recesses with a smaller diameter are evenly distributed on an annular body of the annular sensing source, and a roller is sleeved on each of the recesses.

11. The device used in laboratories to measure horizontal displacement of soil around a region to be treated by vacuum preloading according to claim 2, characterized in that the sensing instrument comprises a sensing instrument body on which a telescopic driving device is provided;

each of the transverse tubes is provided with a telescopic rod which is driven by the telescopic driving device;

the sensor is arranged at an end of the telescopic rod;

the telescopic driving device and a sensing device of the sensing instrument are connected to a programmable logic controller which is programmed to send a signal to the telescopic driving device at regular intervals to urge the telescopic driving device to drive the telescopic rod and the sensor to do one telescopic motion forward or backward; and

during the telescopic motion, the programmable logic controller records the position of the annular sensing source whenever sensed by each sensor.

12. The device used in laboratories to measure horizontal displacement of soil around a region to be treated by vacuum preloading according to claim 2, characterized in that the loading device comprises a support;

a hydraulic device is provided on a cross bar of the support;

a chassis is extended downward from the hydraulic device and resisted against the seal membrane to form a positive pressure.

13. A method for measuring horizontal displacement of soil around a region to be treated by vacuum preloading, by using the device used in laboratories to measure horizontal displacement of soil around a region to be treated by vacuum preloading according to claim 2, comprising the following steps:

A;

injecting dredger fill into a box of the device for measuring horizontal displacement of soil around a region to be treated by vacuum preloading;

burying a vertical drainage board and a vacuum pumping tube within soil in the region to be treated, with the vacuum pumping tube being provided with a vacuum degree detector, a lower end of the vacuum pumping tube being connected to the plastic drainage board and an upper end thereof being connected to a vacuum pump, and a seal membrane covering or wrapping soil in the region to be treated so that the interior of the seal membrane is kept sealed;

then activating the vacuum pump so that a negative pressure is formed below the seal membrane; and

loading above the seal membrane by using the loading device to form a positive pressure;

B;

inserting the sensor into the transverse tubes at regular intervals and recording the sensed position of the annular sensing source; and

C;

calculating the amount of displacement of the annular sensing source according to the data of the position of the annular sensing source sensed by the sensor, detecting and obtaining the vacuum degree data by using a vacuum degree detector, calculating and loading the data by the loading device, and establishing a test model together with the amount of displacement, the loading force data, the vacuum degree data and the time span.