CN115096487B - Pressure measuring device and method for soil - Google Patents

Abstract

The invention relates to a device and a method for measuring the pressure of soil, comprising a container, a hydraulic sensor, a sensing device, a protective shell and a signal acquisition and transmission system for acquiring the pressure signal of the hydraulic sensor; the two ends of the container are opened, a cavity is formed in the container, the hydraulic sensor and the sensing device are respectively arranged at the two opening ends of the cavity of the container, and the middle of the cavity is filled with liquid; the end of the hydraulic sensor is an inner measuring end, and the end of the sensing device is an outer sensing end; the hydraulic sensor is sealed in a sealed space by the protective shell, the inner measuring end is arranged in the protective shell, and the outer sensing end extends out of the protective shell; the method does not need to calculate the force through the deformation, can directly measure the force, and has high pressure measurement precision of the soil; the diaphragm or piston structure is adopted, so that the soil pressure can be measured; by adopting the structures of the diaphragm, the lantern ring and the filter screen, the pore pressure in the soil can be measured more accurately.

Description

A pressure measuring device and method for soil

Technical field

The invention relates to the field of pressure detection, and in particular to a pressure measurement device and method for soil.

Background technique

At present, in the process of engineering construction and scientific research, the characteristics of soil parameters are involved, such as: soil pressure, soil pore pressure, groundwater level, groundwater pressure and other parameters. In the existing technology, the force is mainly calculated by using the deformation amount. Obtain relevant parameters, but it is usually accompanied by situations where the operating conditions are inconsistent with the calibration conditions. For example, when the soil layer is under pressure, the soil layer undergoes continuous deformation, and the modulus of the soil is always changing. At this time, using the deformation amount to calculate the soil pressure will Error occurs and the soil pressure cannot be accurately measured. In addition, some earth pressure sensors now can directly measure soil pressure, but they cannot measure pore pressure. At present, there is no device that can accurately measure the pressure characteristic parameters of soil under various conditions in real time.

Contents of the invention

In view of the above defects, the present invention proposes a pressure measurement device and method for soil. This device can measure the pressure characteristic parameters of the soil without deformation transformation. The measured value is not affected by the deformation modulus of the soil and the measurement accuracy is high. high.

A pressure measuring device for soil, including a container, a hydraulic sensor, a sensing device, a protective shell and a signal acquisition and transmission system for collecting pressure signals from the hydraulic sensor, where the hydraulic sensor is electrically connected to the signal acquisition and transmission system;

The container is open at both ends, and a cavity is formed inside. The hydraulic sensor and the sensing device are respectively arranged at the two open ends of the cavity of the container, and the middle is filled with liquid; the end where the hydraulic sensor is located is the inner measuring end, and the sensing device is located One end is the external sensing end; the hydraulic sensor is used to measure the liquid pressure in the container, and the sensing device is used to sense the external pressure and transmit the pressure to the hydraulic sensor through the liquid filled in the cavity;

The protective shell is used to seal the hydraulic sensor in a closed space, the inner sensing end and the hydraulic sensor are arranged in the protective shell, and the outer sensing end extends out of the protective shell; this ensures that the hydraulic sensor can only communicate with the inside of the container. The end in contact with the liquid is stressed to avoid pressure around the hydraulic sensor, thus ensuring the accuracy of equipment measurement;

When measuring soil pressure, the container, hydraulic sensor, induction device and protective shell are all placed in the soil layer to be measured, and the signal acquisition and transmission system is set outside the soil layer to be measured. The signal acquisition and transmission system communicates with the soil layer through lines. Hydraulic sensor connection.

In this structure, when the pressure of the external soil acts on the sensing device, the sensing device transmits the relevant pressure to the liquid in the container, and the hydraulic sensor directly measures the liquid pressure. There is no need to calculate the force through deformation to obtain the correlation of the force. parameters, the measurement data is more accurate.

Basically, in order to be able to measure soil mechanical parameters in different directions, the container is a straight pipe or a bent pipe. When the container is a straight pipe structure, it can be set in the vertical direction within the soil. The end faces of the inner and outer sensing ends of the container are parallel to the horizontal plane, so that it can be used to measure the pressure from above the soil; when the container is a curved pipe structure , the end face of the inner measuring end of the container is parallel to the horizontal plane, and the end face of the external sensing end faces the side of the soil. This structure can be used to measure the pressure from the side of the soil. In addition, the normal direction of the end face of the external sensing end is the direction of pressure measurement. By changing the container The embedding direction or different bend angles can also be used to measure the soil pressure in other directions.

On this basis, the container may be a constant-diameter pipe or a variable-diameter pipe. When the container is a reducing tube, the inner diameter of the reducing tube changes continuously, and the end surface area of the external sensing end is larger than the end surface area of the internal sensing end. Since the hydraulic sensor connected to the inner measuring end is a standard part, the size of the end face of the inner measuring end is relatively fixed. If the area of the external sensing end is too small, it will be easily affected by factors such as boundary friction and large particle diameter stuck pipes. Therefore, increasing the area of the external sensing end will help improve the efficiency of the system. measurement accuracy.

Option 1: The sensing device is a first filter that allows pore water to pass through, and the first filter is fixedly connected to the external sensing end of the container. The device container is connected to the outside and is mainly used to measure the pore water pressure of saturated soil, the water level in non-confined soil, and the water pressure in pressurized water and its changes.

Option 2: The sensing device is a diaphragm, and the diaphragm is fixedly connected to the container at the external sensing end; and the diaphragm, the hydraulic sensor and the container cooperate to seal the liquid filled in the container into the cavity of the container. The container of this device is not connected to the outside. When external pressure is transmitted to the diaphragm, the diaphragm will deform, thereby squeezing the liquid in the container and transmitting the pressure to the hydraulic sensor, thereby measuring the corresponding earth pressure.

Option 3: Based on Option 2, the sensing device is a diaphragm. The side of the diaphragm away from the hydraulic sensor is provided with a collar for transmitting pore pressure to the diaphragm. The collar is fixedly connected to the container. The collar is filled with sand; the end of the collar away from the container is provided with a second filter screen, a pressure-bearing plate and an iron mesh that only allow liquids and gases to pass through. The two sides of the second filter screen are support bearings. Pressure plate and collar. The iron mesh can block the soil material and prevent the soil material from entering the through hole of the pressure-bearing plate and squeezing the sand in the collar, thereby improving the measurement accuracy. The pressure-bearing plate can withstand the pressure of the soil without deforming. The second filter can seal the filled sand in the collar to prevent the sand from overflowing, and block a small amount of soil that passes through the pressure-bearing plate outside the collar, so that the device can accurately measure the pore pressure in the soil. The pore pressure can be pore water pressure and pore air pressure.

Option 4: The induction device is a propeller. The propeller includes a housing and a piston arranged in the housing. The piston is slidingly connected to the housing. The piston seals the liquid in the container in a closed space. One end of the piston away from the hydraulic sensor bears the pressure of the soil to be measured, and the piston slides in the housing after bearing the pressure. This piston structure is more sensitive to changes in earth pressure, so that the measured earth pressure has real-time and dynamic characteristics, and has higher accuracy and sensitivity than the second option.

On this basis, in order to prevent losses such as evaporation of water in the container and extend the service life of the equipment, a diaphragm is also provided between the piston and the shell to prevent the loss of water in the container. When the diaphragm is installed, the container can be inhibited from The liquid inside evaporates along the piston gap.

On this basis, a protective film is provided at one end of the piston away from the hydraulic sensor. Setting up a protective film can prevent soil from entering the gap between the shell and the piston and blocking the piston.

A soil pressure measurement method, using the above-mentioned pressure measurement device for soil, the specific method is:

S1. Place the pressure measuring device quietly in the air according to the installation angle without applying any load. The signal acquisition and transmission system collects the signal detected by the hydraulic sensor, which is the initial pressure value;

S2. Place the pressure measuring device in the soil to be measured according to the angle in S1;

Among them, the container, hydraulic sensor, induction device and protective shell of the device are buried in the soil to be measured;

S3. The sensing device senses the pressure of the soil to be measured and transmits the pressure to the hydraulic sensor through the liquid filled in the cavity;

S4. The signal acquisition and transmission system collects the pressure signal detected by the hydraulic sensor, which is the measured pressure value, and the soil pressure value obtained is the difference between the measured pressure value and the initial pressure value.

The beneficial aspects of the present invention are: 1. Since the pressure measurement accuracy is related to the equivalent modulus of the diaphragm, the modulus of the soil is changing during the compaction process, and the matching degree of the earth pressure value is poor. The present invention does not need to pass the deformation amount. By calculating the force, the force can be measured directly, and the soil pressure measurement accuracy is high; 2. The present invention can measure the soil pressure in different directions through different orientations of the external sensing end; 3. The present invention only installs a filter at the external sensing end, and the installation The water level can be measured in non-pressurized water soil, and the water pressure and its changes in the soil can be measured when installed in pressurized water. There is no need to install a water level pipe. The water level information can be obtained in real time through this device; 4. The present invention installs a membrane at the external sensing end. The diaphragm or piston can be used to measure earth pressure with high accuracy and sensitivity; 5. In the present invention, after installing a diaphragm at the external sense end and adding a collar filled with sand, the pore pressure in the soil can be measured with high accuracy.

Description of the drawings

Figure 1 is a schematic diagram of the overall structure of the pressure measuring device for soil in Embodiment 1;

Figure 2 is a schematic structural diagram of the container described in Embodiment 1 being a reducer;

Figure 3 is a schematic structural diagram of the sensing device described in Embodiment 2;

Figure 4 is a schematic structural diagram of the sensing device described in Embodiment 3;

Figure 5 is a schematic structural diagram of the sensing device described in Embodiment 4;

Figure 6 is a schematic structural diagram of the pressure-bearing plate described in Embodiment 4;

Figure 7 is a schematic structural diagram of the sensing device described in Embodiment 5;

Figure 8 is a schematic structural diagram of the propeller described in Embodiment 5;

Figure 9 is a schematic structural diagram of a diaphragm arranged between the sensing device and the container described in Embodiment 5.

Detailed ways

In order to further elaborate on the technical means and effects adopted by the present invention to achieve the intended inventive purpose, the specific implementation manner, structure, features and effects of the present invention are described in detail below with reference to the accompanying drawings and preferred embodiments.

Example 1

A pressure measuring device for soil, as shown in Figure 1, includes a container 1, a hydraulic sensor 2, a sensing device 3, a protective shell 4 and a signal acquisition and transmission system 5 for collecting the pressure signal of the hydraulic sensor 2; the present invention The pressure in the middle soil includes earth pressure and pore pressure in the soil.

Specifically, the container 1 is open at both ends, and a cavity 1-1 is formed inside. The hydraulic sensor 2 and the sensing device 3 are respectively arranged at the two open ends of the cavity 1-1 of the container 1, and the middle is filled with liquid. ; The hydraulic sensor 2 and the sensing device 3 can be fixed with the container 1 through threads, buckles, etc.; the liquid in the container 1 can be water or oil. Since oil may cause environmental pollution problems, it is preferred to use it in the present invention. The liquid is water, and the hydraulic sensor 2 is a water pressure sensor. The specific model can be XG-131 pressure transmitter.

The end where the hydraulic sensor 2 is located is the internal measuring end 1-2, and the end where the sensing device 3 is located is the external sensing end 1-3; the hydraulic sensor 2 is used to measure the liquid pressure in the container 1, and the sensing device 3 is used to sense The external pressure transmits the pressure to the hydraulic sensor 2 through the liquid filled in the cavity 1-1; when the pressure of the external soil acts on the sensing device 3, the sensing device 3 transmits the relevant pressure to the liquid in the container 1, which is controlled by the hydraulic pressure. The sensor 2 directly measures the liquid pressure and does not need to calculate the force through deformation to obtain force-related parameters, and the measurement data is more accurate.

Preferably, the end of the hydraulic sensor 2 that is in contact with the liquid in the container 1 is placed horizontally. Since the hydraulic sensor 2 is measured by the pressure of the liquid in the container 1, and there are slight differences in the liquid pressure at different heights, the end that is in contact with the liquid pressure is placed horizontally. It can eliminate the influence of liquid height on the accuracy of pressure measurement.

The protective shell 4 is used to seal the hydraulic sensor 2 in a closed space. The inner sensing end 1-2 and the hydraulic sensor 2 are arranged in the protective shell 4. The outer sensing end 1-3 extends out of the protective shell 4. ; In order to accurately measure the liquid pressure in the container 1, it must be ensured that only the end of the hydraulic sensor 2 that is in contact with the liquid in the container 1 is stressed. The protective shell 4 covers the hydraulic sensor 2 in a closed space to prevent the hydraulic sensor 2 from being affected by the surrounding pressure. pressure, thereby ensuring the accuracy of equipment measurement; preferably, the protective case 4 is made of waterproof material and has a certain waterproof function, thereby avoiding the possible impact of the pore water around the protective case 4 on the hydraulic sensor 2;

The signal collection and transmission system 5 includes a power supply 5-1, a sensor information transmitting device 5-2 for collecting and transmitting the pressure signal of the hydraulic sensor 2, and a signal receiving device 5-3 for receiving information from the sensor information transmitting device 5-2. The power supply 5-1 supplies power to the sensor information transmitting device 5-2 and the hydraulic sensor 2. The signal of the hydraulic sensor 2 is collected by the sensor information transmitting device 5-2 and then transmitted to the signal receiving device 5-3 for processing. Preferably, in this embodiment, the sensor information transmitting device 5-2 can be a TP302 RTU transmitting device, and the signal receiving device 5-3 can be the Tint Internet of Things platform, and its information is stored at the website https://www.tlink.io/ In the database of index.htm, the user logs in to the URL https://www.tlink.io/index.htm to download the data.

In addition, when using this device to measure soil pressure, the container 1, hydraulic sensor 2, sensing device 3 and protective shell 4 are all buried in the soil layer to be measured, and the signal acquisition and transmission system 5 is set in the soil layer to be measured. outside.

On this basis, in order to be able to measure soil mechanical parameters in different directions, the container 1 can be a straight pipe or a bent pipe. As shown in Figure 3 (a), Figure 4 (c), Figure 5 (e) and Figure 7 (g), the container 1 has a straight pipe structure. As a way, the straight pipe is arranged in the soil. In the vertical direction of the body, the end surfaces of the internal sensing ends 1-2 and the external sensing ends 1-3 are parallel to the horizontal plane. This structure can be used to measure the pressure from above the soil body; as shown in Figure 3 (b) and Figure 4 (d), as shown in (f) in Figure 5 and (h) in Figure 7, the container 1 is an elbow structure. As a way, the end surface of the inner sensing end 1-2 is parallel to the horizontal plane, and the end surface of the outer sensing end 1-3 The end face faces the side of the soil, and this structure can be used to measure the pressure from the side of the soil. In addition, the normal direction of the external sense end face is the direction of pressure measurement. By changing the embedding direction of the container or setting different elbow angles, the soil pressure in other directions can also be measured. That is to say, the soil pressure in any direction can be measured in the embedding direction. Or the container bending angle can be solved.

On this basis, the container 1 may be a constant-diameter pipe or a variable-diameter pipe. Among them, the constant-diameter tube refers to the inner diameter of the container 1 that does not change from the end face of the inner sense end 1-2 to the end face of the outer sense end 1-3, as shown in Figures 3 to 5 and 7; the variable diameter pipe refers to The end surface area of the external sense end 1-3 of the container 1 is greater than the end surface area of the inner sense end 1-2, and the inner diameter of the container 1 changes continuously from the end face of the inner sense end 1-2 to the end face of the outer sense end 1-3, As shown in Figure 2, this structure can be better suitable for large-grained soil layers. Since the hydraulic sensor 2 connected to the inner sensing end 1-2 is a standard part, the end surface size of the inner sensing end 1-2 is relatively fixed. If the area of the external sensing end 1-3 is too small, it will be easily affected by boundary friction, large particle diameter stuck and other factors. Therefore, increasing the area of external sense terminals 1-3 is beneficial to improving measurement accuracy.

Example 2

On the basis of Embodiment 1, the sensing device 3 in this embodiment is the first filter 3-2, and other components remain unchanged. Only the sensing device 3 will be described in detail below:

As shown in Figure 3, the sensing device 3 is a first filter 3-2. The first filter 3-2 allows pore water to pass through. The first filter 3-2 is at the external sensing end 1 of the container 1. -3 is fixedly connected to the container 1 to connect the container 1 to the external environment. This structure is mainly used to measure the pore water pressure of saturated soil, the water level in non-pressurized soil, and the water pressure in pressurized water. Variety. When the soil layer is under pressure, since the surrounding soil layers are in a saturated state, the pore water can only be transferred to the container 1 through the first filter 3-2. The liquid pressure before and after the pore water acts is measured by the hydraulic sensor 2, and the calculation is Pore water pressure of saturated soil. If the external sense end 1-3 of the first filter 3-2 is installed in the soil of non-pressure water, the water level can be measured. If it is installed in the pressure-bearing water, the water pressure and its changes in the soil can be measured. The non-pressure water level can be measured. The water level and pressure changes of the pressurized water are calculated from the water pressure. In addition, this structure does not need to install a water level pipe when measuring water level. A cable can be directly connected to a place where it is inconvenient to install a water level pipe. For working conditions that are not suitable for laying out water level monitoring facilities, water level information can be obtained in real time through this structure.

Example 3

On the basis of Embodiment 1, the sensing device 3 in this embodiment is the diaphragm 3-1, and other components remain unchanged. Only the sensing device 3 will be described in detail below:

As shown in Figure 4, the sensing device 3 is a diaphragm 3-1. The diaphragm 3-1 is fixedly connected to the container 1 at the external sensing end 1-3 of the container 1. The diaphragm 3-1, hydraulic pressure The sensor 2 cooperates with the container 1 to seal the liquid filled in the container 1 within the container 1 and is not connected to the external environment. Preferably, the diaphragm 3-1 has a certain elasticity, which means that the diaphragm 3-1 can bend and recover after bending; the diaphragm 3-1 can withstand the pressure of the soil, and its hardness can be determined according to It is designed according to the soil pressure environment to ensure that it will not be damaged when it withstands the pressure of the soil; the diaphragm 3-1 can be a metal sheet.

When external pressure is transmitted to the diaphragm 3-1, the diaphragm 3-1 will deform, thereby squeezing the liquid in the container 1, and then transmit the pressure to the hydraulic sensor 2. The liquid pressure measured by the hydraulic sensor 2 is calculated. Get the magnitude of the external pressure. If the pressure parameter is obtained by calculating the force from the deformation, then the accuracy of the pressure parameter is related to the equivalent modulus of the soil and the diaphragm. During the compaction process, since the modulus of the soil is changing, the pressure value obtained thus matches The degree is poor and the accuracy is low. However, the structure of this embodiment can directly measure the force without deformation conversion. The force measurement process is not affected by the deformation modulus, and the pressure measurement accuracy is high.

Specifically, the device is placed in the soil and when measuring the soil pressure: before loading, the reading of the hydraulic sensor 2 is the initial water pressure value in the container 1; after loading, the reading of the hydraulic sensor 2 is the actual measured water pressure value in the container 1. , the magnitude of the earth pressure is the measured value of the water pressure in container 1 minus the initial value. This structure can accurately measure the pressure value before and after the soil action, and then directly obtain the accurate value of the soil pressure. The soil for this structure measurement can be saturated soil or unsaturated soil containing pore water, or soil without pore water.

Example 4

On the basis of Embodiment 3, in order to accurately measure the pore pressure in the soil, as shown in Figure 5, the side of the diaphragm 3-1 away from the hydraulic sensor 2 is provided with a hole for transmitting pores to the diaphragm 3-1. The pressure collar 3-3 is fixedly connected to the container 1; the end of the collar 3-3 away from the container 1 is provided with a pressure-bearing plate 3-4 and a second filter screen 3-5. The pressure-bearing plate 3-4 and the second filter screen 3-5 are both fixed on the collar 3-3. The two sides of the second filter screen 3-5 are respectively the collar 3-3 and the pressure-bearing plate. 3-4, the cavity formed between the diaphragm 3-1, the collar 3-3, and the second filter 3-5 is filled with sand; wherein, as shown in Figure 6, the pressure-bearing plate 3-4 There are several through holes 3-41 for the passage of gas and/or liquid. The pressure-bearing plate 3-4 has a certain hardness and can withstand the pressure of external soil without deformation. Preferably, the The pressure-bearing plate 3-4 is a porous metal plate; as shown in Figure 5, the second filter screen 3-5 only allows liquids and gases to pass through, and does not allow solids to pass through. That is to say, the second filter screen 3 in the present invention -5 only allows pore water and air to pass through, and does not allow soil material to pass through. In addition, the second filter screen 3-5 can also seal the filled sand material in the collar 3-3 to prevent the sand material from overflowing.

On this basis, as shown in Figure 5, the side of the pressure-bearing plate 3-4 away from the collar 3-3 is also provided with an iron mesh 3-8. The iron mesh 3-8 can protect most of the soil. A small amount of soil passing through the iron mesh 3-8 is blocked for the second time by the pressure-bearing plate 3-4. This can prevent a large amount of soil from gathering at the through hole 3-41 of the pressure-bearing plate 3-4. Squeezing the sand in the collar 3-3 can further improve the measurement accuracy.

After this device is placed on the soil, the pore water sequentially passes through the iron mesh 3-8, the through hole 3-41 on the pressure-bearing plate 3-4 and the second filter screen 3-5 and enters the collar 3-3, and The iron mesh 3-8 and the pressure-bearing plate 3-4 stop the earth material twice, so that most of the earth material is isolated from the collar 3-3 by the iron mesh 3-8 and the pressure-bearing plate 3-4. , a very small amount of soil may enter the through hole 3-41 of the pressure-bearing plate 3-4, and will also be isolated from the collar 3-3 by the second filter 3-5, thereby only allowing pore water to enter the collar Within 3-3. The pore water entering the collar 3-3 fills the sand, and then acts on the diaphragm 3-1, causing the diaphragm 3-1 to deform, thereby transmitting force to the liquid in the container 1, and is controlled by the hydraulic sensor. 2. Measure the pressure. The pressure measured at this time is only related to the pore pressure in the soil. In addition, the sand material is standard sand with uniform particle size and evenly distributed in the collar 3-3. When the pore water and/or air enter the collar 3-3, they are evenly dispersed along the gaps of the sand material, so that the pore pressure is even. Act evenly on the diaphragm 3-1 to prevent excessive pressure somewhere from causing excessive deformation and failure of the diaphragm 3-1, thereby protecting the diaphragm 3-1.

Preferably, the diaphragm 3-1 in this embodiment can isolate the liquid in the container 1, has a certain degree of flexibility, and can deform under slight pressure, and can be made of materials such as vinyl and latex. This kind of diaphragm is relatively sensitive to pressure and can improve the accuracy of pressure measurement.

Compared with the device in Example 2, this structure can clearly measure the pressure as pore pressure, which includes pore water pressure and pore air pressure, and the measurement accuracy is higher and the effect is better.

Example 5

On the basis of Embodiment 1, in order to accurately measure the pressure of the soil in the soil, as shown in Figures 7 and 8, the sensing device 3 is a propeller 3-6, and the propeller 3-6 includes a shell. body 3-61 and a piston 3-62 arranged in the housing 3-61. The housing 3-61 is fixedly connected to the container 1. The piston 3-62 is inserted into the housing 3-61. The piston 3 The end of -62 away from the hydraulic sensor 2 bears the pressure of the soil to be measured. After bearing the pressure, the piston 3-62 slides in the housing 3-61. The piston 3-62 seals the liquid in the container 1 in a closed space. . Preferably, the outer diameter of the piston 3-62 is equal to the inner diameter of the housing 3-61.

When the pressure of the soil acts on the piston 3-62, the end of the piston 3-62 away from the hydraulic sensor 2 bears the pressure of the soil to be measured. After bearing the pressure, the piston 3-62 slides in the housing 3-61, and the piston 3 -62 approaches the direction of the hydraulic sensor 2 and acts on the liquid in the container 1. The liquid pressure is measured by the liquid sensor 2, and then the earth pressure is obtained. The soil to be tested in this structure can be saturated soil or unsaturated soil containing pore water, or soil without pore water.

On this basis, as shown in Figure 9, in order to reduce the liquid loss in the container 1, a diaphragm 3-1 is provided between the propeller 3-6 and the container 1, the diaphragm 3-1 and the hydraulic sensor 2. Seal the liquid filled in the container 1 into the container 1. Preferably, the diaphragm 3-1 has a certain degree of flexibility and can deform under slight pressure, and can be made of materials such as ethylene, latex, etc. This diaphragm 3-1 can seal the liquid in the container 1 and prevent the evaporation loss of the liquid in the container 1 after the device is used for a long time, thereby extending the service life of the equipment and ensuring the accuracy of the device.

Preferably, the housing 3-61 and the piston 3-62 can be industrial cylinders, and the specific model can be: SDA12X10.

On this basis, as shown in Figure 7, the end of the piston 3-62 away from the hydraulic sensor 2 is provided with a protective film 3-7. The protective film 3-7 can be wrapped and fixed on the outer wall of the housing 3-61 , or can be wrapped and fixed on the outer wall of the container 1. The protective film 3-7 can prevent soil from entering the gap between the housing 3-61 and the piston 3-62, and avoid blocking the piston 3-62.

Compared with the device of Embodiment 3, the piston 3-62 of the device of this embodiment is more sensitive to changes in earth pressure, so that the measured earth pressure has real-time and dynamic characteristics, so that the device has higher accuracy and sensitivity.

Example 6

A soil pressure measurement method, using the pressure measurement device for soil described in any one of Example 1 to Example 5, the specific method is:

S1. Place the pressure measuring device for soil in the air according to the installation angle without applying any load. The signal acquisition and transmission system 5 collects the pressure signal detected by the hydraulic sensor 2 as the initial pressure value;

The installation angle here refers to the angle set during installation after the device is buried in the soil to be measured.

S2. Place the pressure measuring device in the soil to be measured according to the angle in S1;

The container 1, hydraulic sensor 2, sensing device 3 and protective shell 4 of the device are embedded in the soil to be measured;

S3. The sensing device 3 senses the pressure of the soil to be measured and transmits the pressure to the hydraulic sensor 2 through the liquid filled in the cavity 1-1;

S4. The signal acquisition and transmission system 5 collects the pressure signal detected by the hydraulic sensor 2 as the actual measured pressure value, and thereby obtains the pressure value of the soil as the difference between the actual measured pressure value and the initial pressure value.

This pressure measurement method directly obtains the magnitude of the force during the detection process. It does not need to calculate the force through deformation. It is not affected by the deformation of the soil, and the measured pressure has high accuracy.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any form. Although the present invention has been disclosed above in preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art , without departing from the scope of the technical solution of the present invention, the technical contents disclosed above can be used to make some changes or modifications to equivalent embodiments with equivalent changes. However, without departing from the technical solution of the present invention, according to the technical solution of the present invention, In essence, any brief modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solution of the present invention.

Claims (6)

1. The pressure measuring device for the soil is characterized by comprising a container (1), a hydraulic sensor (2), an induction device (3), a protective shell (4) and a signal acquisition and transmission system (5) for acquiring pressure signals of the hydraulic sensor (2);

the two ends of the container (1) are opened, a cavity (1-1) is formed in the container, the hydraulic sensor (2) and the sensing device (3) are respectively arranged at the two open ends of the cavity (1-1) of the container (1), and the middle of the container is filled with liquid; the end of the hydraulic sensor (2) is an inner measuring end (1-2), and the end of the sensing device (3) is an outer sensing end (1-3); the hydraulic sensor (2) is used for measuring the liquid pressure in the container (1), and the sensing device (3) is used for sensing the external pressure and transmitting the pressure to the hydraulic sensor (2) through the liquid filled in the cavity (1-1);

the protection shell (4) is used for sealing the hydraulic sensor (2) in a closed space, the inner measuring end (1-2) and the hydraulic sensor (2) are arranged in the protection shell (4), and the outer sensing end (1-3) extends out of the protection shell (4);

the induction device (3) is a diaphragm (3-1), and the diaphragm (3-1) is fixedly connected with the container (1) at the outer induction end (1-3); the diaphragm (3-1), the hydraulic sensor (2) and the container (1) are matched to seal the liquid filled in the container (1) in the cavity (1-1) of the container (1);

one side of the diaphragm (3-1) far away from the hydraulic sensor (2) is provided with a lantern ring (3-3) for transmitting pore pressure to the diaphragm (3-1), the lantern ring (3-3) is fixedly connected with the container (1), and the lantern ring (3-3) is filled with sand; the one end that container (1) was kept away from to lantern ring (3-3) is provided with bearing plate (3-4) and only allows second filter screen (3-5) of liquid and gaseous through, bearing plate (3-4) can bear the pressure of soil and do not warp, second filter screen (3-5) both sides are lantern ring (3-3) and bearing plate (3-4) respectively, bearing plate (3-4) and second filter screen (3-5) are all fixed connection on lantern ring (3-3).

2. The pressure measurement device for the earth according to claim 1, characterized in that the container (1) is a straight or curved tube.

3. The pressure measurement device for the earth according to claim 1, characterized in that the container (1) is an isopipe or reducer pipe; when the container (1) is a reducer pipe, the inner diameter of the reducer pipe is continuously changed, and the end surface area of the outer sensing end (1-3) is larger than the end surface area of the inner sensing end (1-2).

4. The soil pressure measuring device according to claim 1, wherein the sensing device (3) is a first filter screen (3-2), the first filter screen (3-2) being fixedly connected to the container (1) at the outer sensing end (1-3).

5. The pressure measuring device for the earth according to claim 1, characterized in that the side of the bearing plate (3-4) remote from the membrane (3-1) is further provided with an iron net (3-8) for blocking the passage of earth material.

6. A method for measuring the pressure of soil, characterized in that the device for measuring the pressure of soil according to any one of claims 1 to 5 is used, comprising the following steps:

s1, standing the pressure measuring device in air according to an installation angle, and acquiring a pressure signal detected by a hydraulic sensor (2) by a signal acquisition and transmission system (5) without applying a load, wherein the pressure signal is an initial pressure value;

s2, placing the pressure measuring device in a soil body to be measured according to the angle in the S1;

s3, sensing the pressure of the soil to be detected by the sensing device (3) and transmitting the pressure to the hydraulic sensor (2) through the liquid filled in the cavity (1-1);

s4, a signal acquisition and transmission system (5) acquires a pressure signal detected by the hydraulic sensor (2), namely an actual measurement pressure value, so that the pressure value of the soil is the difference value between the actual measurement pressure value and the initial pressure value.