Device for detecting pore water pressure in soft soil foundation

Abstract

The utility model discloses a pore water pressure detection device in a soft soil foundation. The pore water pressure detection device comprises a press-in rod, a placing groove body connected outside the press-in rod, and a pressure detection structure installed in the placing groove body, the pressure detection structure comprises a pore water pressure sensor and a fixing support hooped on a pore water pressure sensor body, and the fixing support is connected to the placing groove body; the fixing support comprises a hoop ring matched with the external size of the pore water pressure sensor, and a connecting rib plate connected to the hoop ring. A cable box is further arranged on the fixing support. According to the utility model, a protection structure can be adopted for the cable, the pore water pressure sensor can be embedded in a specified elevation position more smoothly, and the detection accuracy is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of road construction, and particularly relates to a pore water pressure detection device in soft soil foundation. Background Technique

[0002] In soft soil foundation, the detection of pore water pressure is one of the important monitoring contents in the fields of geological engineering, geotechnical engineering, civil engineering, etc. Such detection devices are usually designed to accurately measure the pore water pressure in the soil, providing key data support for engineering design, construction and later maintenance.

[0003] When measuring the pore water pressure, a pore water pressure sensor is mainly used. The sensor usually adopts a steel string type or a resistance strain type, which can sense the change of pore water pressure and convert it into a measurable physical quantity. The pore water enters the inside of the sensor through the permeable stone, acts on the pressure-bearing diaphragm, causes the deflection of the center of the diaphragm, and then changes the stress state of the steel string or the resistance strain gauge. Finally, the pore water pressure value is measured by a frequency meter or a strain gauge.

[0004] However, in the prior art, when measuring, the drilling embedding method or the pressing-in embedding method is mainly adopted to embed the pore water pressure sensor to the elevation position. But in both of these methods, the cable will bear a large force, and once the cable is damaged, it is extremely easy to affect the acquisition of data. Content of the Utility Model

[0005] The purpose of the utility model is to provide a pore water pressure detection device in soft soil foundation, which adopts a protection structure for the cable, can more smoothly embed the pore water pressure sensor to the designated elevation position, and improves the detection accuracy.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is specifically as follows:

[0007] A pore water pressure detection device in soft soil foundation, comprising a pressing rod, a placement groove body connected to the outside of the pressing rod, and a pressure detection structure installed in the placement groove body; the pressure detection structure includes a pore water pressure sensor, a fixing bracket clamped on the body of the pore water pressure sensor, and the fixing bracket is connected to the placement groove body; the fixing bracket includes a clamping ring adapted to the external size of the pore water pressure sensor, and a connecting rib plate connected to the clamping ring; a cable box is also arranged on the fixing bracket.

[0008] Further, the placement groove body is a cavity with a closed lower part and an open upper part, and the lower part of the placement groove body is set to be conical.

[0009] Further, the cavity is filled with coarse sand.

[0010] Further, the clamping ring is formed by splicing two arc-shaped pieces with bolts.

[0011] Further, the connecting rib plates are respectively welded to the inner wall of the placement groove body and different arc-shaped pieces of the hoop ring.

[0012] Further, the cable box includes a box body connected to the top of the fixed bracket, a rotating shaft disposed in the middle of the box body, and a cable wound around the driving shaft.

[0013] Further, the cable passes through the box body and is connected to the pore water pressure sensor.

[0014] Compared with the prior art, the advantages of the present utility model are as follows: First, in view of the characteristics of soft soil foundation, the present utility model directly selects the press-in embedding method, reducing the processes such as drilling operation and hole cleaning operation, and saving the construction period. Second, on the other hand, the present utility model uses a placement groove provided on the press-in rod to fix the pore water pressure sensor, and uses a cable box to play a good role in protecting the cable, avoiding the problem that the cable bears too much pressure during the cable laying process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present utility model, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 It is a schematic structural diagram of the pore water pressure detection device in the soft soil foundation provided by the present utility model.

[0017] Reference numerals: 1, press-in rod; 2, placement groove body; 3, coarse sand; 4, hoop ring; 5, pore water pressure sensor; 6, connecting rib plate; 7, cable box; 8, rotating shaft; 9, cable. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] In order to make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts fall within the protection scope of the present utility model.

[0019] It should be noted that: similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0020] In the description of the present utility model, it should be noted that if terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is customarily placed during use. This is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0021] In addition, if terms such as "first", "second", "third", etc. are used only for distinguishing descriptions, they cannot be understood as indicating or implying relative importance.

[0022] In addition, if terms such as "horizontal", "vertical", "hanging" do not mean that the component is required to be absolutely horizontal or hanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0023] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and defined, if terms such as "set", "installed", "connected", "connected" are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0024] It should be noted that, without conflict, the features in the embodiments of the present utility model can be combined with each other.

[0025] As Figure 1 shown, a pore water pressure detection device in soft soil foundation includes a pressing rod 1, a placement groove body 2 connected to the outside of the pressing rod 1, and a pressure detection structure installed in the placement groove body 2; the pressure detection structure includes a pore water pressure sensor 5, a fixing bracket clamped on the body of the pore water pressure sensor 5, and the fixing bracket is connected to the placement groove body 2; the fixing bracket includes a clamping ring 4 adapted to the external size of the pore water pressure sensor 5, and a connecting rib plate 6 connected to the clamping ring 4; a cable box 7 is also provided on the fixing bracket.

[0026] Compared with the prior art, in the prior art, the installation of the pore water pressure sensor 5 is a common monitoring method in the fields of geotechnical engineering, hydrogeology, etc., mainly used to measure the groundwater pressure or the change of pore water pressure in the soil mass. During the pressing-in process of the traditional press-in installation sensor, workers need to hold the cable 9 to ensure that the position of the sensor does not shift, so there will be a large amount of force on the cable 9. And after one-time pressing-in, there will be problems such as difficult recycling and reuse, increasing the overall cost.

[0027] Since the main applicable occasion of the present utility model is soft soil foundation, directly selecting the press-in installation method, compared with the drilling method, the press-in installation method can further save the construction period and improve the detection efficiency. Slowly press the pore water pressure sensor 5 directly to the installation elevation. During the pressing-in process, the sensor needs to be kept perpendicular to the ground to avoid tilting or twisting.

[0028] At the same time, the present utility model selects to connect a placement groove body 2 on the pressing rod 1, and directly uses the placement groove body 2 to fix the pore water pressure sensor 5. It can effectively fix the sensor after it is pressed in place, preventing it from moving or falling off due to external forces. At the same time, during the pressing-in process, using the placement groove body 2 for pressing in, the pore water pressure sensor 5 can also avoid being strongly impacted or squeezed.

[0029] The placement groove body 2 is a cavity with a closed lower part and an open upper part, and the lower part of the placement groove body 2 is set to be conical. By using the conical placement groove body 2, it can be better stressed during the pressing-in process.

[0030] The cavity is filled with coarse sand 3. Using the coarse sand 3 to cover the pore water pressure sensor 5 to make its upper part well sealed to ensure that the sensor is not interfered by the outside world during the pressing-in process. Of course, in order to meet the connection with the outside soil mass, a plurality of communication holes need to be provided on the placement groove body 2, and a hanging net is provided on the communication holes to prevent the coarse sand 3 from leaking out.

[0031] The hoop ring 4 is formed by splicing two arc-shaped pieces with bolts. The connecting rib plates 6 are respectively welded to the inner wall of the placement groove body 2 and different arc-shaped pieces of the hoop ring 4. The hoop ring 4 can effectively fix the pore water sensor.

[0032] The cable box 7 includes a box body connected to the top of the fixed bracket, a rotating shaft 8 arranged in the middle of the box body, and a cable 9 wound around the driving shaft. The cable 9 passes through the box body and is connected to the pore water pressure sensor 5. The cable box 7 can protect the cable 9, make the cable 9 have a certain margin, and avoid problems such as the cable 9 being taut during the pressing-in process.

[0033] During actual use, before use, select a suitable pore water pressure sensor 5 to ensure that its accuracy, range, stability, etc. meet the monitoring requirements. Conduct necessary inspections and calibrations on the sensor, such as stability and sealing inspections and pressure calibrations. Boil the permeable stone of the sensor in boiling water for a period of time to remove internal air bubbles and keep it soaked and saturated in clean water.

[0034] During use, the pore water pressure sensor 5 can be directly fixed on the hoop ring 4 and locked with bolts. And lay a certain amount of coarse sand 3 in the placement groove body 2 so that it can cover the upper part of the interstitial water pressure sensor to prevent the entry of impurities. Of course, in order to prevent the coarse sand 3 from leaking out from the communication holes in contact with the external soil body, soaking treatment can be carried out during the filling of the coarse sand 3.

[0035] After the coarse sand 3 is filled, directly press the entire pressing rod 1 into the specified elevation position of the specified soft soil foundation, and observe whether the pore water pressure sensor 5 is working properly after connecting the cable 9. If not, the pressing rod 1 needs to be taken out for adjustment and then pressed in again.

[0036] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A pore water pressure detection device in soft soil foundation, characterized in that: It includes a pressing rod (1), a placement groove body (2) connected to the outside of the pressing rod (1), and a pressure detection structure installed in the placement groove body (2); the pressure detection structure includes a pore water pressure sensor (5), a fixing bracket clamped on the body of the pore water pressure sensor (5), and the fixing bracket is connected to the placement groove body (2); the fixing bracket includes a clamping ring (4) adapted to the external size of the pore water pressure sensor (5), and a connecting rib plate (6) connected to the clamping ring (4); a cable box (7) is also arranged on the fixing bracket.

2. The pore water pressure detection device in soft soil foundation according to claim 1, characterized in that: The placement groove body (2) is a cavity with a closed lower part and an open upper part, and the lower part of the placement groove body (2) is set to be conical.

3. The pore water pressure detection device in soft soil foundation according to claim 2, characterized in that: The cavity is filled with coarse sand (3).

4. The pore water pressure detection device in soft soil foundation according to claim 1, characterized in that: The clamping ring (4) is formed by splicing two arc-shaped pieces with bolts.

5. The pore water pressure detection device in soft soil foundation according to claim 1, characterized in that: The connecting rib plates (6) are respectively welded to the inner wall of the placement groove body (2) and different arc-shaped pieces of the clamping ring (4).

6. The pore water pressure detection device in soft soil foundation according to claim 1, characterized in that: The cable box (7) includes a box body connected to the top of the fixing bracket, a rotating shaft (8) arranged in the middle of the box body, and a cable (9) wound around the driving shaft.

7. The pore water pressure detection device in soft soil foundation according to claim 6, characterized in that: The cable (9) passes through the box body and is connected to the pore water pressure sensor (5).

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