Pore water pressure measurement integrated device

Abstract

The utility model discloses a pore water pressure measuring integrated device which comprises a conical head, a plurality of measuring assemblies and a plurality of isolating assemblies, and the measuring assemblies and the isolating assemblies are arranged at intervals from bottom to top. The measuring assembly comprises a pore water pressure gauge and a measuring pipe body, the pore water pressure gauge is used for monitoring the pore water pressure of the position where the measuring pipe body is located, and the lower end of the measuring pipe body is detachably connected with the conical head; the upper end of the measuring pipe body is detachably connected with the lower end of the sealing pipe body of the isolation assembly, the upper end of the sealing pipe body is used for being detachably connected with the lower end of another measuring pipe body, and the upper end of the uppermost sealing pipe body can be used for being connected with external equipment. The pore water pressure measuring integrated device can measure pore water pressure at different elevation positions at the same time by being pressed into a soil layer at a time, construction is convenient, operation is easy, the conical head, the measuring assembly and the isolation assembly can be recycled, and the construction cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of geotechnical engineering, in particular to an integrated device for measuring pore water pressure. Background Art

[0002] In traditional pore water pressure measurements, one pore water pressure gauge is usually buried in one hole. When multiple pore water pressure gauges are to be buried at different depths in the same hole, it is necessary to use dry soil balls or expansive mature soil to strictly isolate the pore water pressure gauges from each other to avoid the penetration of pore water pressure between the upper and lower layers. Otherwise, the purpose of measuring the changes in pore water pressure at each depth cannot be achieved. Existing pore water pressure gauge burial methods include drilling and pressing. Drilling is to first drill a hole with a drill rig, and then place the pore water pressure gauge at the designed elevation, which is suitable for all types of soil layers. However, in the drilling method, it is difficult to seal the hole between the upper and lower pore water pressure gauges, and it relies on sealing with water-insulating materials such as bentonite mud balls or relying on pulling out the pipe to collapse the hole for sealing. In the former, the bentonite mud ball is usually unable to sink to the designed isolation position due to the shrinkage of the pores. The latter has a poor sealing effect and generally cannot meet the monitoring requirements. The press-in burial method is to press the pore water pressure gauge directly into the predetermined depth. It has a fast construction speed and low cost and is suitable for soft soil layers. However, this method is usually only applicable to burying a pore water pressure gauge in a plane position.

[0003] The existing method of burying pore water pressure gauges has multiple defects:

[0004] Pore water pressure gauges cannot be reused. Whether buried by drilling or direct pressing, due to the large burial depth, pore water pressure gauges are generally left in the soil and not recovered.

[0005] Pore-water piezometers have a low survival rate. In soft soil, direct press-in installation exposes the pore-water piezometer and its conductors to direct friction with the existing soil, which can easily cause the conductors to break or damage the pore-water piezometer. When drilling, the hole is typically protected with casing, which is then removed after the pore-water piezometer is installed. However, the cable is easily damaged during the lowering of the pore-water piezometer and the removal of the casing.

[0006] Excess pore-water pressure dissipates slowly, leading to long waiting times for measurements. For soft soils like silt and muddy materials, which have low permeabilities, the burial method is easy to insert, resulting in high excess pore-water pressure that cannot be dissipated in time. This can even exceed the pore-water pressure gauge's measuring range, causing damage to the equipment. Therefore, insertion can only be intermittent, and after full insertion, the excess pore-water pressure generated during the burial process must be largely dissipated before formal measurements can be taken. For soft soils with low permeabilities and deep burial depths of pore-water pressure gauges, the dissipation of excess pore-water pressure can take days or even months, making it difficult to adapt to tight project schedules. Utility Model Content

[0007] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides an integrated device for measuring pore water pressure, which is easy to construct, can be reused, and effectively reduces costs.

[0008] According to an embodiment of the first aspect of the present invention, an integrated device for measuring pore water pressure includes a cone head, a plurality of measuring components and a plurality of isolation components, wherein the measuring components and the isolation components are spaced apart from each other from bottom to top;

[0009] A piezoresistive hydraulic sensor is provided in the cone head, and a water-permeable member is provided on the side wall of the cone head. The water-permeable member is used to allow pore water outside the cone head to flow to the piezoresistive hydraulic sensor. The piezoresistive hydraulic sensor is used to monitor the dissipation of excess pore water pressure at the cone head in real time.

[0010] The measuring assembly includes a pore water pressure gauge, a measuring tube body, a first water-gas pipe and a flow meter, the first water-gas pipe is provided with a branch pipe, the branch pipe is provided with a solenoid valve and the flow meter, the flow meter is annular and sleeved on the first water-gas pipe, multiple channels of the flow meter are radially distributed to spray air / water or extract air / water to the peripheral wall of the measuring tube body, the solenoid valve is used to open and close the flow meter, the first water-gas pipe, the pore water pressure gauge and the flow meter are all arranged in the measuring tube body, the outer wall of the measuring tube body is provided with multiple communicating holes, the communicating holes, the flow meter and the first water-gas pipe are used to pass water or ventilation in sequence, the pore water pressure gauge is used to monitor the pore water pressure at the position of the measuring tube body, and the lower end of the measuring tube body is detachably connected to the cone head;

[0011] The isolation assembly includes a sealed tube body, a second water and gas pipe and two partition plates, the two partition plates respectively seal the two ends of the sealed tube body, the second water and gas pipe passes through the two partition plates, the upper end of the measuring tube body is detachably connected to the lower end of the sealed tube body, the lower end of the second water and gas pipe is detachably connected to the upper end of the first water and gas pipe, the upper end of the sealed tube body is used to be detachably connected to the lower end of another measuring tube body, the upper end of the topmost sealed tube body can be used to connect to external equipment, the upper end of the second water and gas pipe is used to be detachably connected to the lower end of the first water and gas pipe of another measuring tube body, the upper end of the second water and gas pipe is used to be detachably connected to a water-gas power device, and the water-gas power device is used to pump air / water or extract air / water.

[0012] It has at least the following beneficial effects:

[0013] When pore water pressure measurement is required, the appropriate number of measuring components and isolation components are selected based on the soil layer and measurement requirements at different elevations. Isolation components of varying lengths can be set based on actual conditions, allowing each measuring component to be located at different elevations. Once the integrated pore water pressure measurement device is pressed into the soil layer, it can simultaneously monitor pore water pressure at different elevations, effectively improving construction and measurement efficiency and offering simple operation. The integrated pore water pressure measurement device can be removed from the soil layer. The cone head, measuring component, and isolation component are detachably connected, making the cone head, measuring component, and isolation component recyclable, reducing construction costs.

[0014] According to some embodiments of the present invention, the pore water pressure gauge is coated with a first filter layer to isolate the mud and sand outside the pore water pressure gauge.

[0015] According to some embodiments of the present invention, the structure of the first filter layer includes a cloth bag and a water-permeable material disposed in the cloth bag, and the pore water pressure gauge is coated in the water-permeable material.

[0016] According to some embodiments of the present invention, the flow device is coated with a second filter layer.

[0017] According to some embodiments of the present invention, the cone head and the measuring tube body, as well as the measuring tube body and the sealing tube body, are connected via fasteners.

[0018] According to some embodiments of the present invention, the measuring tube body includes two half shells opened in half.

[0019] According to some embodiments of the present invention, a receiving groove is provided on the conical surface of the cone head, the piezoresistive hydraulic sensor is arranged in the receiving groove, and the permeable member is a permeable stone, which is arranged at the notch of the receiving groove.

[0020] According to some embodiments of the present invention, a bus interface is provided in the measuring tube body, the piezoresistive hydraulic sensor is electrically connected to the bus interface through a first cable, the pore water pressure meter is electrically connected to the bus interface through a second cable, the bus interface is connected to a bus, the bus is connected to a data acquisition instrument, and the data acquisition instrument is electrically connected to a data processing device.

[0021] According to some embodiments of the present invention, the control line of the solenoid valve is electrically connected to the bus interface, a wire hole is provided on the sealing tube body, the inner cavity of the measuring tube body and the wire hole are used for the bus to pass through, and sealant is provided between the inner wall of the wire hole and the bus.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0024] Figure 1 This is a schematic structural diagram of an integrated device for measuring pore water pressure according to an embodiment of the present utility model;

[0025] Figure 2 for Figure 1 A partial enlarged schematic diagram of point A in the middle;

[0026] Figure 3 for Figure 1 A partial enlarged schematic diagram of point B in the middle;

[0027] Figure 4 This is a schematic structural diagram of an integrated device for measuring pore water pressure according to another embodiment of the present invention;

[0028] Figure 5 This is a schematic cross-sectional view of a measuring tube in an integrated device for measuring pore water pressure according to an embodiment of the present invention;

[0029] Figure 6 is the Ut curve;

[0030] Figure Number:

[0031] Cone head 100, piezoresistive hydraulic sensor 110, storage tank 120, permeable member 130, measuring assembly 200, pore water pressure gauge 210, first filter layer 211, measuring tube body 220, connecting hole 221, first water-gas pipe 230, flow pass 240, isolation assembly 300, sealing tube body 310, second water-gas pipe 320, solenoid valve 400, fastener 500, bus 600, bus interface 700. DETAILED DESCRIPTION

[0032] The following describes in detail embodiments of the present invention. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0033] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0034] In the description of this utility model, "a plurality" means more than two. The use of "first" or "second" is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features indicated, or implicitly indicating the order of the technical features indicated.

[0035] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0036] Reference Figure 1 、 Figure 2 and Figure 4 The utility model discloses an integrated device for measuring pore water pressure, comprising a cone head 100, a plurality of measuring components 200 and a plurality of isolation components 300, wherein the measuring components 200 and the isolation components 300 are spaced apart from each other from bottom to top;

[0037] A piezoresistive hydraulic pressure sensor 110 is provided in the cone head 100, and a water-permeable member 130 is provided on the side wall of the cone head 100. The water-permeable member 130 is used to allow pore water outside the cone head 100 to flow to the piezoresistive hydraulic pressure sensor 110. The piezoresistive hydraulic pressure sensor 110 is used to monitor the dissipation of excess pore water pressure at the cone head 100 in real time.

[0038] The measuring assembly 200 includes a pore water pressure gauge 210, a measuring tube 220, a first water-air pipe 230, and a flow meter 240. The first water-air pipe 230 is provided with a branch pipe, and the branch pipe is provided with an electromagnetic valve 400 and a flow meter 240. The flow meter 240 is annular and sleeved on the first water-air pipe 230. The multiple channels of the flow meter 240 are radially distributed to spray air / water or extract air / water to the peripheral wall of the measuring tube 220. The electromagnetic valve 400 is used to open and close the The flow meter 240, the first water-gas pipe 230, the pore water pressure gauge 210, and the flow meter 240 are all disposed within the measuring tube body 220. A plurality of communication holes 221 are formed on the outer wall of the measuring tube body 220. The communication holes 221, the flow meter 240, and the first water-gas pipe 230 are used to sequentially pass water or air. The pore water pressure gauge 210 is used to monitor the pore water pressure at the location of the measuring tube body 220. The lower end of the measuring tube body 220 is detachably connected to the cone head 100.

[0039] The isolation assembly 300 includes a sealed tube body 310, a second water and gas pipe 320 and two partition plates 330. The two partition plates 330 respectively seal the two ends of the sealed tube body 310. The second water and gas pipe 320 passes through the two partition plates 330. The upper end of the measuring tube body 220 is detachably connected to the lower end of the sealed tube body 310. The lower end of the second water and gas pipe 320 is detachably connected to the upper end of the first water and gas pipe 230. The upper end of the sealed tube body 310 is used to be detachably connected to the lower end of another measuring tube body 220. The upper end of the uppermost sealed tube body 310 can be used to connect to external equipment. The upper end of the second water and gas pipe 320 is used to be detachably connected to the lower end of the first water and gas pipe 230 of another measuring tube body 220. The upper end of the uppermost second water and gas pipe 320 is used to be detachably connected to a water-gas power device, which is used to pump air / water or extract air / water.

[0040] When pore water pressure measurement is required, an appropriate number of measuring components 200 and an appropriate number of isolation components 300 are selected according to the soil layer and the measurement requirements at different elevations. Several measuring components 200 and several isolation components 300 are arranged at intervals from bottom to top, and the cone head 100 is connected to the lower end of the lowest measuring component 200, thereby obtaining the required integrated pore water pressure measurement device.

[0041] It is understood that the external device connection can be a press-in device used to press the integrated pore water pressure measurement device into the soil layer, or a pull-out device used to pull the integrated pore water pressure measurement device out of the soil layer. Press-in devices and pull-out devices are common devices on the market and are not redundantly introduced here.

[0042] When the integrated pore water pressure measuring device is pressed into the soil layer, and the soil layer outside the cone head 100 contains pore water, the pore water contacts the piezoresistive hydraulic pressure sensor 110 inside the cone head 100 through the permeable member 130. The piezoresistive hydraulic pressure sensor 110 is immersed in the pore water, and the piezoresistive hydraulic pressure sensor 110 can dynamically monitor the pore water pressure. The piezoresistive hydraulic pressure sensor 110 has a high sensitivity.

[0043] The isolation component 300 has the function of isolating the two measuring components 200. The top isolation component 300 is used to connect with an external pressing device or a pulling-out device. The pressing device can be used to press the integrated pore water pressure measuring device into the soil layer where the pore water pressure needs to be tested, and the pulling-out device can be used to pull the integrated pore water pressure measuring device out of the soil layer.

[0044] The cone head 100 and the measuring assembly 200, as well as the measuring assembly 200 and the isolation assembly 300, are detachably connected. The number of measuring assemblies 200 and isolation assemblies 300 can be selected according to actual needs, and isolation assemblies 300 of different lengths can be set according to actual conditions, so that each measuring assembly 200 is at a different elevation. The pore water at the corresponding different elevations enters the measuring tube body 220 through the connecting holes 221 on each measuring tube body 220 and contacts the pore water pressure gauge 210. The pore water pressure gauge 210 of each measuring assembly 200 is immersed in the pore water at different elevations. After the excess pore water pressure generated by the pore water pressure measurement integrated device being pressed into the soil layer has basically dissipated, each pore water pressure gauge 210 can monitor the pore water pressure at the location of different measuring tube bodies 220, that is, the pore water pressure at different elevations can be monitored simultaneously. The integrated pore water pressure measurement device is pressed into the soil layer once and can measure the pore water pressure at several elevations, which can effectively improve the construction and measurement efficiency and has a simple operation method.

[0045] The isolation assembly 300 provides no electrical conduction between two adjacent measuring assemblies 200, effectively reducing the risk of pore water crossflow at different elevations and improving the accuracy of each pore water pressure gauge 210 and the entire integrated pore water pressure measurement device. Furthermore, the equal outer diameters of the sealing tube 310 and the measuring tube 220 enhance the seal between the sealing tube 310, the measuring tube 220, and the soil layer, further preventing pore water crossflow at different elevations.

[0046] Several first water-gas pipes 230 and several second water-gas pipes 320 are connected in intervals from bottom to top. Each first water-gas pipe 230 is connected to a flow meter 240, which is located within the measuring tube body 220. The upper end of the uppermost second water-gas pipe 320 is detachably connected to a water-gas power device, which is used to pump air / water or extract air / water. The water-gas power device, the second water-gas pipes 320, the first water-gas pipes 230, and the flow meter 240 remove water and / or gas that enters the measuring tube body 220, accelerating the dissipation of excess pore water pressure. This allows for timely detection of pore water pressure at different elevations, improving the efficiency of pore water pressure detection. Gas and / or water are pumped into the measuring tube body 220 through the water-gas power device, the second water-gas pipe 320, the first water-gas pipe 230 and the flow device 240, and the gas and / or water are discharged to the outside of the measuring tube body 220 through the connecting hole 221, thereby preventing and clearing blockage of the connecting hole 221.

[0047] Since the first water-gas pipe 230 is provided with a branch pipe, the branch pipe is provided with an electromagnetic valve 400 and a flow meter 240, the electromagnetic valve 400 is used to open and close the flow meter 240, and the first water-gas pipe 230 and the flow meter 240 are both arranged in the measuring tube body 220, so by controlling different electromagnetic valves 400, the opening and closing of the flow meters 240 in different measuring components 200 can be controlled, thereby achieving pumping air / water or exhausting air / water for the measuring components 200 at different elevations, thereby accelerating the dissipation of the excess pore water pressure of the outer soil wall of the measuring components 200 at different elevations, or preventing and clearing blockage of the connecting holes 221 of the measuring components 200 at different elevations.

[0048] The hydro-pneumatic system includes a high-pressure water supply system, a pumping system, and a high-pressure gas supply system. The high-pressure water supply system is used to deliver high-pressure water into the measuring tube 220, the pumping system is used to remove pore water within the measuring tube 220, and the high-pressure gas supply system is used to deliver high-pressure gas into the measuring tube 220. The high-pressure water pressure can reach 10.0 MPa or higher. The high-pressure gas pressure can reach 6.3 MPa or higher. The high-pressure water supply system, pumping system, and high-pressure gas supply system can all use commonly available equipment, so redundant descriptions are omitted here.

[0049] The integrated pore water pressure measuring device can be pulled out of the soil layer by a pulling-out device. The cone head 100 and the measuring component 200, as well as the measuring component 200 and the isolation component 300, are connected in a detachable manner, which facilitates the maintenance and replacement of the cone head 100, the measuring component 200 and the isolation component 300. Moreover, the cone head 100, the measuring component 200 and the isolation component 300 can all be recycled, thereby reducing construction costs.

[0050] In summary, the integrated pore water pressure measurement device has the following advantages:

[0051] ①. By pressing the integrated pore water pressure measurement device into the soil layer, the pore water pressure at different elevations can be measured simultaneously, achieving rapid and synchronous measurement of multiple targets. The construction workload is small, the construction method is simple, and the construction efficiency is high.

[0052] ②. The water-gas power device, the second water-gas pipe 320, the first water-gas pipe 230, the branch pipe, the solenoid valve 400, and the flow device 240 can pump away pore water, accelerate the dissipation of excess pore water pressure, and improve the efficiency of pore water pressure measurement; the water-gas power device, the second water-gas pipe 320, the first water-gas pipe 230, the branch pipe, the solenoid valve 400, and the flow device 240 can pump water or gas into the measuring tube body 220 to prevent the connecting hole 221 from being blocked. The second water-gas pipe 320, the first water-gas pipe 230, the branch pipe, the solenoid valve 400, the flow device 240, and the measuring tube body 220 have a self-cleaning function;

[0053] ③ The isolation assembly 300 separates two adjacent measurement assemblies 200, effectively reducing the risk of pore water channeling at different elevations. Compared with traditional isolation methods, it has lower construction requirements, better anti-channeling effect, and higher reliability.

[0054] ④. The cone head 100, the measuring assembly 200 and the isolation assembly 300 can be disassembled, which facilitates the maintenance, replacement and recycling of the cone head 100, the measuring assembly 200 and the isolation assembly 300, thereby reducing construction costs.

[0055] In this embodiment, there are two measuring components 200 and two isolation components 300. The cone head 100, one measuring component 200, one isolation component 300, another measuring component 200 and another isolation component 300 are detachably connected in sequence from bottom to top, and the upper end of the uppermost isolation component 300 can be used to connect to an external device.

[0056] The second water / gas pipe 320 passes through the upper and lower ends of the sealed tube body 310. Specifically, the second water / gas pipe 320 passes through the two partition plates 330 on the sealed tube body 310. The second water / gas pipe 320 is sealedly connected to the first water / gas pipe 230, preventing water and air leakage between the second water / gas pipe 320 and the first water / gas pipe 230. The partition plates 330 are provided with a relief hole for the second water / gas pipe 320 to pass through. The second water / gas pipe 320 is sealedly connected to the inner wall of the relief hole, preventing water or air leakage between the second water / gas pipe 320 and the partition plates 330.

[0057] It is understood that the structure of the flowmeter 240 in the bottommost measuring assembly 200 may differ from that of the flowmeters 240 in other measuring assemblies 200. The flowmeter 240 in the bottommost measuring assembly 200 may be directly connected to the lower end of the first water-gas pipe 230, and the solenoid valve 400 is disposed on the first water-gas pipe 230. All flowmeters 240 have multiple channels arranged around the outer shell of the flowmeter 240 and distributed radially, so that water / gas can pass through the multiple channels to reach most or all of the communication holes 221 in the measuring tube body 220, thereby clearing most or all of the communication holes 221 in the measuring tube body 220.

[0058] See also Figure 4 In another embodiment, the number of the cone head 100, the measuring component 200 and the isolation component 300 is one each, and the cone head 100, the measuring component 200 and the isolation component 300 are detachably connected in sequence from bottom to top, and the upper end of the topmost isolation component 300 can be used to connect to an external device.

[0059] See also Figure 1In some embodiments, the pore water pressure gauge 210 is covered with a first filter layer 211 , and the first filter layer 211 further isolates mud and sand outside the pore water pressure gauge 210 to ensure the normal operation of the pore water pressure gauge 210 .

[0060] In some embodiments, the structure of the first filter layer 211 includes a cloth bag and a water-permeable material disposed within the cloth bag. The pore water pressure gauge 210 is enclosed in the water-permeable material, and the cloth bag serves to enclose the water-permeable material and the pore water pressure gauge 210. The water-permeable material is commonly available on the market and will not be described in detail here.

[0061] The flow device 240 is covered with a second filter layer (not shown in the figure), which can further prevent foreign matter such as mud and sand from entering the flow device 240, the branch pipe and the first water-gas pipe 230, thereby preventing the branch pipe, the first water-gas pipe 230, the second water-gas pipe 320 and the water-gas power device from being blocked and damaged.

[0062] The flow passage 240 is essentially a water distributor having a plurality of channels on its outer surface. The flow passage 240, pore water pressure gauge 210, piezoresistive hydraulic pressure sensor 110 and solenoid valve 400 are all common components on the market and will not be described here redundantly.

[0063] See also Figure 3 In some embodiments, the cone head 100 and the measuring tube body 220 as well as the measuring tube body 220 and the sealing tube body 310 are connected by fasteners 500. The fasteners 500 can be fastened and detached. The fasteners 500 can be bolts, screws, or screws.

[0064] An inner flange is provided on the inner edge of the end face of the measuring tube body 220, and an outer flange is provided on the outer edge of the end face of the sealing tube body 310. The outer flange wraps around the inner flange, and the outer and inner flanges are sealed together. Alternatively, an outer flange is provided on the outer edge of the end face of the measuring tube body 220, and an inner flange is provided on the inner edge of the end face of the sealing tube body 310. The outer flange wraps around the inner flange, and the outer and inner flanges are sealed together. The outer and inner flanges enhance the overall bending resistance of the integrated pore water pressure measurement device. The outer and inner flanges are provided with connection holes and threaded holes, respectively. The threaded section of the fastener 500 passes through the connection hole and is threadedly connected to the inner wall of the threaded hole.

[0065] See also Figure 5In some embodiments, the measuring tube body 220 comprises two half-shells, which are assembled to form the measuring tube body 220. A guide groove and a guide rail are respectively provided on two flat surfaces of the half-shells. The lengths of the guide grooves and guide rails are parallel to the lengths of the half-shells. The guide grooves on one half-shell mate with the guide rails on the other half-shell, and vice versa, ensuring the precision of the splicing of the two half-shells. Furthermore, the internal width of the guide grooves is greater than the width of the guide groove openings, and the guide rails' outer shape mates with the internal space of the guide grooves. After the guide rails are inserted into the guide grooves, the two half-shells cannot be directly separated, thereby improving the connection and structural strength of the two half-shells.

[0066] Of course, the two half shells can be connected by welding. The measuring tube body 220 can also be made in an integral molding manner.

[0067] See also Figure 1 In some embodiments, a receiving groove 120 is opened on the conical surface of the cone head 100, and the piezoresistive hydraulic sensor 110 is arranged in the receiving groove 120. The permeable member 130 is a permeable stone, which is arranged at the notch of the receiving groove 120. The permeable member 130 can allow water to penetrate into the receiving groove 120 while blocking mud and sand from entering the receiving groove 120, so that the piezoresistive hydraulic sensor 110 can be submerged in water without being damaged by mud and sand, and the piezoresistive hydraulic sensor 110 can measure the pore water pressure.

[0068] In some embodiments, a bus interface 700 is provided in the measuring tube body 220, the piezoresistive hydraulic sensor 110 is electrically connected to the bus interface 700 via a first cable, the pore water pressure meter 210 is electrically connected to the bus interface 700 via a second cable, the bus interface 700 is connected to the bus 600, the bus 600 is connected to a data acquisition instrument, and the data acquisition instrument is electrically connected to the data processing device.

[0069] In some embodiments, the control line of the solenoid valve 400 is electrically connected to the bus interface 700, and the bus 600 is electrically connected to the controller, which controls the opening and closing of the solenoid valve 400. The data processing device receives and displays the measurement results of the piezoresistive hydraulic pressure sensor 110 and the pore water pressure gauge 210, and the data processing device can control the opening and closing of the solenoid valve 400.

[0070] The sealing tube 310 is provided with a wire hole. The inner cavity of the measuring tube 220 and the wire hole are used to allow the bus 600 to pass through. Sealant is provided between the inner wall of the wire hole and the bus 600. The first cable, second cable, and control line are all installed on the inner walls of the measuring tube 220 and the sealing tube 310, reducing the risk of wear and tear on the first cable, second cable, and control line. The bus interface 700 and bus 600 facilitate the rapid electrical connection and disconnection of each piezoresistive hydraulic sensor 110 and each pore water pressure gauge 210 with the data processing device.

[0071] It is conceivable that the bus bar 600 and the inner wall of the wire hole can be sealed with sealant. Bus bar 600 is a wiring harness. One end of bus bar 600 has multiple first terminals, and the other end of bus bar 600 has multiple second terminals, with the multiple first terminals corresponding to the multiple second terminals. Bus bar 600 is a common component on the market.

[0072] The pore water pressure measurement construction method includes the following steps.

[0073] Assembly of the integrated device for measuring pore water pressure in soft soil: Determine the burial depth, vertical spacing, and number of pore water pressure gauges 210, then select the number of cone heads 100, measurement assemblies 200, and isolation assemblies 300. Pre-saturate the indoor air supply of the pore water pressure gauges 210 to be installed, and complete the assembly of the cone heads 100, measurement assemblies 200, and isolation assemblies 300 on the ground.

[0074] Pressing the integrated device for measuring pore water pressure in soft soil into the soil layer to be measured at a certain rate using the pressing device. During the pressing process, the electromagnetic valve 400 is opened and the data of the pore water pressure meter 210 is read. , is the i-th pore pressure value, so that the connecting hole 221, the flow device 240, the first water-air pipe 230 and the second water-air pipe 320 are connected to form a channel, so that the excess pore water generated by the integrated device for measuring pore water pressure in soft soil during the process of being pressed into the soil layer is discharged from the soil layer through the channel, thereby accelerating the rapid dissipation of the excess pore water pressure. Specifically, when ≤ hour, is the critical value of the i-th pore pressure value, that is, when any pore water pressure gauge 210 accumulates to the critical value, the rate of pressing into the soil layer is reduced or water is pumped through the channel to forcibly reduce the pore water pressure. The rate of pressing into the soil layer and the pumping power are dynamically adjusted with the pore water pressure gauge 210. By monitoring the dissipation law of the excess pore water pressure, the rate of pressing into the soil layer and the pumping power are dynamically adjusted until the integrated device for measuring pore water pressure in soft soil reaches the target depth position. If the connecting hole 221 is blocked by mud and sand, resulting in slow dissipation of the excess pore water pressure, pumping is stopped, and water or air is pumped into the channel to flush out the mud and sand blocking the connecting hole 221, so as to keep the connecting hole 221 unobstructed.

[0075] Waiting for the excess pore water pressure to dissipate: After the integrated device for measuring pore water pressure in soft soil is pressed to the target depth, the total pore water pressure value at different times t is monitored by the piezoresistive hydraulic sensor 110. Excess pore water pressure = - h, get -t curve, such as Figure 6 ,in is the gravity of water, h is the vertical distance between the cone head 100 and the groundwater level;

[0076] like > According to the excess pore water pressure values at two moments in the Ut curve, the following formula is used to estimate the time when U is reduced to Time required , , where It is the maximum excess pore water pressure allowed to remain in the soil when the excess pore water pressure has basically dissipated. and They are Moment and The excess pore water pressure at the moment, and the dissipation time of the excess pore water pressure are all taken as the initial zero time when the cone head is pressed into the target depth by 100 degrees;

[0077] like < , The waiting time allowed by engineering monitoring after the cone head 100 is pressed in is the time to wait for the excess pore water pressure to dissipate before formally measuring the pore water pressure. Otherwise, > , it means that the waiting time is too long. At this time, pumping should be continued to speed up the dissipation of excess pore water pressure until < , formula derivation: ( Derivation, according to the dissipation law formula of excess pore water pressure: , thus we can deduce: ; , this formula is transformed into + );

[0078] Pore water pressure measurement: When the excess pore water pressure dissipates to the required level After the pressure drops below 0.5, stop pumping, close the electromagnetic valve 400, and wait for the pore water pressure gauge 210 reading to stabilize, and then record the initial value of each pore water pressure gauge 210. , start pore water pressure measurement;

[0079] Pull out and clean the integrated device for measuring pore water pressure in soft soil: Pull out the integrated device for measuring pore water pressure in soft soil from the soil layer and lay it flat on the ground. Then, open the solenoid valve 400 and pump water into the channel to clean the mud and sand remaining in the measuring tube body 220, the flow meter 240, the first water-air pipe 230, and the second water-air pipe 320. Then, pump air into the channel to empty the water in the measuring tube body 220, the flow meter 240, the first water-air pipe 230, and the second water-air pipe 320.

[0080] Disassembling the integrated device for measuring pore water pressure in soft soil: disassembling the cone head 100 , the measuring assembly 200 , and the isolation assembly 300 to recycle and use the cone head 100 , the measuring assembly 200 , and the isolation assembly 300 .

[0081] It should be understood that the construction method for measuring pore water pressure in soft soil adopts the above-mentioned integrated device for measuring pore water pressure in soft soil.

[0082] The pore water pressure measurement construction method has all the beneficial effects brought by the integrated pore water pressure measurement device of the above embodiment, and will not be repeated here.

[0083] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] Of course, the present invention is not limited to the above-mentioned embodiments. Those skilled in the art may make equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. An integrated device for measuring pore water pressure, characterized in that: include: A cone head (100), a plurality of measuring components (200) and a plurality of isolation components (300), wherein the measuring components (200) and the isolation components (300) are spaced apart from bottom to top; A piezoresistive hydraulic sensor (110) is provided in the cone head (100), and a water-permeable member (130) is provided on the side wall of the cone head (100). The water-permeable member (130) is used to allow pore water outside the cone head (100) to flow to the piezoresistive hydraulic sensor (110). The piezoresistive hydraulic sensor (110) is used to monitor the dissipation of excess pore water pressure at the cone head (100) in real time. The measuring assembly (200) comprises a pore water pressure gauge (210), a measuring tube (220), a first water-air pipe (230) and a flow meter (240). The first water-air pipe (230) is provided with a branch pipe, and the branch pipe is provided with an electromagnetic valve (400) and the flow meter (240). The flow meter (240) is annular and sleeved on the first water-air pipe (230). The plurality of holes of the flow meter (240) are radially distributed to spray air / water or extract air / water to the peripheral wall of the measuring tube (220). The electromagnetic valve (400) is used to open and close the flow meter. (240), the first water-gas pipe (230), the pore water pressure gauge (210) and the flow device (240) are all arranged in the measuring tube body (220), a plurality of communication holes (221) are opened on the outer wall of the measuring tube body (220), the communication holes (221), the flow device (240) and the first water-gas pipe (230) are used to pass water or air in sequence, the pore water pressure gauge (210) is used to monitor the pore water pressure at the position where the measuring tube body (220) is located, and the lower end of the measuring tube body (220) is detachably connected to the cone head (100); The isolation assembly (300) includes a sealing tube body (310), a second water-gas tube (320) and two partition plates (330), wherein the two partition plates (330) respectively seal the two ends of the sealing tube body (310), and the second water-gas tube (320) passes through the two partition plates (330). The upper end of the measuring tube body (220) is detachably connected to the lower end of the sealing tube body (310), and the lower end of the second water-gas tube (320) is detachably connected to the upper end of the first water-gas tube (230). The upper end of the sealing tube body (310) is used to be detachably connected to the lower end of another measuring tube body (220), the upper end of the uppermost sealing tube body (310) can be used to be connected to an external device, the upper end of the second water-gas pipe (320) is used to be detachably connected to the lower end of the first water-gas pipe (230) of another measuring tube body (220), and the upper end of the uppermost second water-gas pipe (320) is used to be detachably connected to a water-gas power device, and the water-gas power device is used to pump air / water or extract air / water.

2. The integrated pore water pressure measuring device according to claim 1, characterized in that: The pore water pressure gauge (210) is coated with a first filter layer (211) to isolate mud and sand outside the pore water pressure gauge (210).

3. The integrated pore water pressure measuring device according to claim 2, characterized in that: The structure of the first filter layer (211) comprises a cloth bag and a water-permeable material arranged in the cloth bag, and the pore water pressure gauge (210) is coated in the water-permeable material.

4. The integrated pore water pressure measuring device according to claim 1, characterized in that: The flow device (240) is coated with a second filter layer.

5. The integrated device for measuring pore water pressure according to claim 1, characterized in that: The cone head (100) and the measuring tube body (220), as well as the measuring tube body (220) and the sealing tube body (310), are all connected via fasteners (500).

6. The integrated device for measuring pore water pressure according to claim 1, characterized in that: The measuring tube body (220) comprises two half shells opened in half.

7. The integrated device for measuring pore water pressure according to claim 1, characterized in that: A receiving groove (120) is provided on the conical surface of the cone head (100), the piezoresistive hydraulic pressure sensor (110) is arranged in the receiving groove (120), and the permeable member (130) is a permeable stone, which is arranged at the notch of the receiving groove (120).

8. The integrated pore water pressure measuring device according to claim 1, characterized in that: A bus interface (700) is provided in the measuring tube body (220); the piezoresistive hydraulic pressure sensor (110) is electrically connected to the bus interface (700) via a first cable; the pore water pressure gauge (210) is electrically connected to the bus interface (700) via a second cable; the bus interface (700) is connected to a bus (600); the bus (600) is connected to a data acquisition instrument; and the data acquisition instrument is electrically connected to a data processing device.

9. The integrated pore water pressure measuring device according to claim 8, characterized in that: The control line of the solenoid valve (400) is electrically connected to the bus interface (700), the sealing tube body (310) is provided with a wire hole, the inner cavity of the measuring tube body (220) and the wire hole are used for the bus (600) to pass through, and a sealant is provided between the inner wall of the wire hole and the bus (600).

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