Vacuum preloading vacuum degree measuring device

Abstract

The utility model relates to the technical field of geotechnical engineering testing, in particular to a vacuum preloading vacuum degree measuring device which comprises a vacuum pressure gauge, a pneumatic hose and a ventilation structure. One end of the pneumatic hose is connected with the vacuum pressure gauge, and the other end of the pneumatic hose is connected with the ventilation structure through a sealing joint; the breathable structure comprises a metal framework, a waterproof breathable film and a breathable stone layer; the metal framework is located on the innermost layer, and a cavity is formed in the middle. The waterproof breathable film is wrapped on the metal framework; and the breathable stone layer is wrapped on the waterproof breathable film. According to the utility model, the vacuum preloading vacuum degree is measured through the breathable structure formed by combining the breathable stone layer, the waterproof breathable film and the metal framework, so that the influence caused by underground water is avoided, and the measurement accuracy is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of geotechnical engineering testing, in particular to a vacuum preloading vacuum degree measuring device. Background Art

[0002] The vacuum drainage preloading method is an effective method for reinforcing soft soil foundations and has been widely used in my country. On-site vacuum measurement, especially vacuum measurement under the sealing membrane, in the soil or in the drainage board, is a key monitoring project in the vacuum preloading construction process. It is of great significance to the soil preloading reinforcement effect, vacuum dissipation, vacuum preloading reinforcement mechanism research, and sealing membrane sealing warning. In the study of the vacuum drainage preloading method, vacuum has always been a key research content. The vacuum under the membrane, in the soil or in the drainage board is an important construction indicator. The vacuum in the drainage board is an important indicator for studying the blockage of the drainage board and the attenuation of the vacuum in the drainage board. The vacuum in the soil is an important parameter for studying the principle of the vacuum drainage preloading method.

[0003] At present, the vacuum degree measurement under the membrane in the field of vacuum preloading in China mostly adopts the method of burying the piezometer in the sand cushion layer to measure the vacuum degree or burying the vacuum tube in the sand cushion layer to measure the vacuum degree with the vacuum gauge. However, when vacuum preloading is used to reinforce the soft soil layer, a large amount of groundwater will be pumped out, which will submerge the piezometer. When the piezometer is used to measure the vacuum degree under the membrane below the groundwater level, the excess pore water is directly measured, which leads to abnormal readings on the vacuum gauge.

[0004] In order to solve the problems existing in the prior art, technicians in this field have made many efforts. For example, Chinese patent application CN108918023A proposes a vacuum degree monitoring device and method for vacuum preloading soil. The vacuum probe wrapped by geotextile cooperates with a pressure gauge to realize equivalent observation of the vacuum degree between the soil and the vacuum probe. However, the soil is only isolated by geotextile, and the groundwater in the soil cannot be isolated, which may easily lead to inaccurate vacuum degree measurement. Utility Model Content

[0005] In order to solve the above problems, the utility model provides a vacuum preload vacuum degree measuring device, which measures the vacuum preload vacuum degree through a breathable structure composed of a breathable stone layer, a waterproof breathable membrane and a metal frame, thereby avoiding the influence of groundwater and improving the measurement accuracy.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is a vacuum preload vacuum degree measuring device, including a vacuum pressure gauge, a pneumatic hose and a breathable structure; one end of the pneumatic hose is connected to the vacuum pressure gauge, and the other end is connected to the breathable structure through a sealing joint; the breathable structure includes a metal frame, a water-proof breathable membrane and a breathable stone layer; the metal frame is located in the innermost layer, and a cavity is formed in the middle; the water-proof breathable membrane is wrapped on the metal frame; the breathable stone layer is wrapped on the water-proof breathable membrane.

[0007] Furthermore, the sealing joint includes a pagoda joint and a locking ring; one end of the pagoda joint is connected to the breathable stone layer and extends into the cavity of the metal skeleton, and the other end is connected to the pneumatic hose; the locking ring is sleeved outside the pneumatic hose to tighten the pneumatic hose to form a sealing effect.

[0008] Furthermore, a waterproof sealant is provided at the connection between the pneumatic hose and the pagoda joint.

[0009] Furthermore, the breathable stone layer is covered with fine pores.

[0010] Furthermore, the breathable stone layer is wrapped with geotextile.

[0011] Furthermore, the metal skeleton is a cubic mesh structure.

[0012] The technical solution described in the utility model has the following beneficial effects:

[0013] 1. The utility model places a metal skeleton in the innermost layer, which is then wrapped with a waterproof breathable membrane and a breathable stone layer to form a breathable structure. The vacuum degree is measured by placing the breathable structure under a sealing membrane, in a soil body or a drainage board. When the breathable structure is placed in saturated soil or unsaturated soil, the breathable stone layer can effectively prevent silt from entering the breathable structure. At the same time, the waterproof breathable membrane can effectively prevent water in the soil body from penetrating into the breathable structure, thereby forming a gas cavity inside the metal skeleton, thereby isolating the influence of silt and water when measuring the vacuum degree, and improving the accuracy of the vacuum measurement.

[0014] 2. The utility model connects the pneumatic hose and the breathable structure through a sealing joint, which ensures the air tightness of the entire device, and plays a good role in isolating the soil by wrapping the geotextile in the outermost layer. The breathable stone layer further avoids the blockage problem easily caused by fine soil, and further improves the accuracy of vacuum measurement.

[0015] 3 The utility model realizes the measurement of vacuum degree under the membrane, in the soil or in the drainage board by cooperating with the air-permeable structure, the pneumatic hose and the vacuum pressure gauge. It has a simple structure and low production cost. It is applicable to the measurement of vacuum degree in the soil and the drainage board and has strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below according to specific embodiments and in combination with the accompanying drawings.

[0017] Figure 1 It is a structural schematic diagram of the vacuum preload vacuum degree measuring device described in the utility model.

[0018] Figure 2 It is a diagram of the internal structure of the breathable structure.

[0019] Figure 3 This is an application scenario diagram of the vacuum preload vacuum degree measuring device described in the utility model.

[0020] Among them, 1-vacuum pressure gauge; 2-pneumatic hose; 3-breathable structure; 4-space between sealing membrane and soil surface; 5-model barrel boundary or soil boundary of field test; 6-geotextile; 7-plastic drainage board; 8-soil to be treated; 9-breathable stone layer; 10-waterproof and breathable membrane; 11-metal skeleton; 12-pagoda joint. DETAILED DESCRIPTION

[0021] The technical solution of the utility model is further explained below in conjunction with the accompanying drawings, but it is not limited to this. Any modification or equivalent replacement of the technical solution of the utility model without departing from the spirit and scope of the technical solution of the utility model should be included in the protection scope of the utility model.

[0022] like Figure 1-3 As shown, this embodiment provides a vacuum preloading vacuum degree measuring device, which is used to measure the vacuum degree under the membrane, in the soil or in the drainage board in the vacuum preloading drainage method; it includes a vacuum pressure gauge 1, a pneumatic hose 2 and a breathable structure 3, one end of the pneumatic hose 2 is connected to the vacuum pressure gauge 1, and the other end is connected to the breathable structure 3 through a sealing joint; the breathable structure 3 includes a metal skeleton 11, two layers of water-proof breathable membranes 10 and a breathable stone layer 9, the metal skeleton 11 is placed in the innermost layer, a cavity is formed in the middle, the two layers of water-proof breathable membranes 10 are wrapped on the metal skeleton 11, and the breathable stone layer 9 is wrapped on the water-proof breathable membrane 10. Among them, the metal skeleton 11 is made of stainless steel, in a rectangular shape, and all its faces are mesh structures; the breathable stone layer 9 is covered with fine pores all over, and is made of high-density corundum and quartz sand sintered at high temperature, with a thickness of 4-6mm.

[0023] The sealing joint includes a pagoda joint 12 and a locking ring. One end of the pagoda joint 12 is pagoda-shaped and the other end is cylindrical, and is integrally formed with the breathable structure 3; the cylindrical end is located inside the breathable structure 3 and extends into the internal cavity of the metal skeleton 11, and the pagoda-shaped end extends out from one side of the breathable structure 3 and is connected to the pneumatic hose 2; the locking ring is sleeved on the pneumatic hose 2, and when the pneumatic hose 2 is connected to the pagoda joint 12, the locking ring can be locked to achieve sealing between the pneumatic hose 2 and the pagoda joint 12.

[0024] Preferably, when the pneumatic hose 2 is connected to the pagoda connector 12, a sealing film is wrapped around the pagoda connector 12 to achieve an interference connection between the pneumatic hose 2 and the pagoda connector 12, thereby further enhancing the sealing effect between the two.

[0025] Preferably, the connection between the pneumatic hose 2 and the pagoda joint 12 is provided with a waterproof sealant, and when in use, a water-proof and airtight raw tape is wrapped around the outside of the joint to further ensure the sealing of the connection between the pneumatic hose 2 and the pagoda joint 12.

[0026] Preferably, the outside of the breathable structure 3 is wrapped with a geotextile 6 to perform preliminary isolation of fine soil.

[0027] Preferably, the vacuum preloading vacuum degree measuring device described in the utility model also includes a test bracket adapted to the air permeable structure 3, which is used to prevent the pressure of the soil layer from damaging the air permeable structure 3 when measuring the vacuum degree of soil with large settlement deformation.

[0028] Working principle:

[0029] When measuring the vacuum degree under the membrane, in the soil or in the drainage board, first install the test instrument bracket in the soil, then wrap three layers of geotextile 6 on the outside of the breathable stone layer 9, fix the breathable structure 3 at the corresponding position of the bracket, and preliminarily isolate the soil through the geotextile 6, and then further isolate the silt and other fine soil through the breathable stone layer 9, and allow the gas mixed with water vapor to penetrate, and then isolate the infiltrated water through the waterproof breathable membrane 10, and only allow the gas to pass through the waterproof breathable membrane 10 and enter the metal frame 11 to form a gas cavity. While ensuring the sealing of all parts of the entire device, the gas in the gas cavity is transported to the vacuum pressure gauge 1 through the pneumatic hose 2, thereby realizing the measurement of the vacuum degree under the membrane, in the soil or in the drainage board.

[0030] The utility model places a metal skeleton 11 in the innermost layer, and again wraps the water-proof breathable membrane 10 and the breathable stone layer 9 to form a breathable structure 3. The vacuum degree is measured by placing the breathable structure 3 under the sealing membrane, in the soil or in a drainage board. When the breathable structure 3 is placed in saturated soil or unsaturated soil, the breathable stone layer 9 can effectively prevent silt from entering the breathable structure 3. At the same time, the water-proof breathable membrane 10 can effectively prevent water in the soil from penetrating into the breathable structure 3, so that a gas cavity can be formed inside the metal skeleton 11, thereby isolating the influence of silt and water when measuring the vacuum degree, thereby improving the accuracy of the vacuum measurement.

[0031] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A vacuum preload vacuum degree measuring device, characterized in that: It comprises a vacuum pressure gauge (1), a pneumatic hose (2) and a breathable structure (3); one end of the pneumatic hose (2) is connected to the vacuum pressure gauge (1), and the other end is connected to the breathable structure (3) via a sealing joint; the breathable structure (3) comprises a metal frame (11), a water-proof breathable membrane (10) and a breathable stone layer (9); the metal frame (11) is located in the innermost layer, and a cavity is formed in the middle; the water-proof breathable membrane (10) is wrapped on the metal frame (11); and the breathable stone layer (9) is wrapped on the water-proof breathable membrane (10).

2. The vacuum preload vacuum degree measuring device according to claim 1, characterized in that: The sealing joint comprises a pagoda joint (12) and a locking ring; one end of the pagoda joint (12) is connected to the breathable stone layer (9) and extends into the cavity of the metal skeleton (11), and the other end is connected to the pneumatic hose (2); the locking ring is sleeved outside the pneumatic hose (2) and is used to tighten the pneumatic hose (2) to form a sealing effect.

3. The vacuum preload vacuum degree measuring device according to claim 2, characterized in that: A waterproof sealant is provided at the connection between the pneumatic hose (2) and the pagoda connector (12).

4. The vacuum preload vacuum degree measuring device according to claim 1, characterized in that: The air-permeable stone layer (9) has a thickness of 4-6 mm and is covered with fine pores.

5. The vacuum preload vacuum degree measuring device according to claim 1, characterized in that: The air-permeable stone layer (9) is also wrapped with a geotextile (6).

6. The vacuum preload vacuum degree measuring device according to claim 1, characterized in that: The metal skeleton (11) is a cubic mesh structure.

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