A measuring method for monitoring the side wall friction of a caisson

Abstract

The application discloses a measuring method for monitoring the side wall friction resistance of a sinking well, which comprises the following steps: a vertical installation groove is formed on the outer wall surface of the sinking well, a spring pressure gauge is fixedly arranged in the installation groove, the spring pressure gauge comprises a pressure sensor arranged at the upper portion and a spring arranged at the lower portion; a sliding plate is arranged outside the installation groove, the lower end of the sliding plate is fixedly connected with the lower end of the spring through a sliding end surface plate, and the inner side surface of the sliding plate is slidably attached to the outer surface of the installation groove and the outer wall surface of the sinking well; the sinking well is subjected to sinking construction; in the sinking process, the spring pressure gauge sinks with the sinking well, the sliding plate is subjected to the action of the outer soil body friction resistance, and the sliding plate generates relative displacement with the spring pressure gauge, the sliding plate presses the spring through the sliding end surface plate, and the pressure sensor monitors the side friction resistance value. The method has the advantages that the friction resistance monitor is directly arranged on the side wall surface of the sinking well, the spring pressure gauge and the sliding plate which can generate relative displacement change are used, and the direct calculation of the side friction resistance is realized.

Description

Technical Field

[0001] This invention belongs to the field of caisson construction technology, specifically relating to a measurement method for monitoring the frictional resistance of the caisson sidewalls. Background Technology

[0002] Caisson structures offer advantages such as small footprint, high safety, and the ability to function as both retaining and main structures, making them highly suitable for urban underground space construction. However, as the diameter and depth of caissons increase, the stress mechanism for caisson sinking becomes unclear, especially the frictional resistance of the caisson sidewalls. Currently, this is mainly measured indirectly through earth pressure on the caisson sidewalls, which has limited accuracy.

[0003] Therefore, there is an urgent need for a method that can directly measure the frictional resistance of the caisson sidewall to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the prior art by providing a method for measuring the frictional resistance of the caisson sidewalls. This method involves setting a spring pressure gauge and a sliding plate on the caisson sidewalls that can generate relative displacement changes, thereby directly measuring the frictional resistance of the caisson sidewalls during the sinking process.

[0005] The objective of this invention is achieved through the following technical solutions:

[0006] A method for monitoring the frictional resistance of the sidewall of a caisson, characterized in that the method includes the following steps:

[0007] S1. A vertical mounting groove is opened on the outer wall of the caisson, and a spring pressure gauge is fixedly installed in the mounting groove. The spring pressure gauge includes a pressure sensor located at the upper part and a spring located at the lower part.

[0008] S2. A sliding plate is provided outside the mounting groove. The lower end of the sliding plate is fixedly connected to the lower end of the spring via a sliding end panel. The inner side of the sliding plate slides against the outer surface of the mounting groove and the outer wall of the caisson.

[0009] S3: The caisson is lowered during the sinking process. During the sinking process, the spring pressure gauge sinks with the caisson. The sliding plate is subjected to the frictional resistance of the outer soil and generates relative displacement with the spring pressure gauge. The sliding plate presses the spring on the sliding end panel so that the pressure sensor can monitor the side frictional resistance value and transmit the data to the data receiver through the data transmission waterproof cable.

[0010] The formula for calculating the side friction resistance value is as follows:

[0011] F = kx ;

[0012] F The side friction resistance value is measured by the spring pressure gauge and is expressed in N.

[0013] k The spring constant is expressed in N / m.

[0014] x The value of the spring's deformation is expressed in meters (m).

[0015] The two ends of the spring pressure gauge are fixed to the upper and lower ends of the mounting groove by a fixing device, so that the spring pressure gauge sinks synchronously with the caisson.

[0016] The spring pressure gauge also includes a sliding groove, the upper end of which is fixedly connected to the pressure sensor, and the lower end of which is fixed to the mounting groove via the fixing device. The spring is located inside the sliding groove, and the sliding end panel is slidably assembled with the sliding groove.

[0017] The lower end of the sliding plate is fixed to the sliding end panel, and the inner side of the sliding plate is slidably attached to the surface of the pressure sensor, the surface of the sliding groove and the outer wall of the caisson. The outer side of the sliding plate is provided with a roughness coating.

[0018] The roughness coating is made of the same material as the outer wall of the caisson.

[0019] The advantages of this invention are: the side wall friction monitoring instrument is fitted to the side wall of the caisson and can sink with the caisson wall. The sliding plate generates a corresponding displacement with the fixed spring pressure gauge under the action of side friction, and transmits the force to the pressure sensor through the high-precision spring, and the data is read by the data receiver. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the caisson sidewall friction monitoring device in its initial state according to the present invention;

[0021] Figure 2 This is a schematic diagram of the caisson sidewall friction monitoring device during the caisson sinking process in this invention. Detailed Implementation

[0022] The features and other related features of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments, so as to facilitate understanding by those skilled in the art:

[0023] like Figure 1-2 The markings in the figure are as follows: 1. Spring pressure gauge, 11. Pressure sensor, 12. Spring, 13. Sliding groove, 14. Sliding end panel, 2. First fixing device, 3. Second fixing device, 4. Sliding plate, 5. Roughness coating, 6. Waterproof data transmission cable, 7. Caisson.

[0024] Example: Figure 1 , 2 As shown, this embodiment specifically relates to a measurement method for monitoring the frictional resistance of the caisson sidewall, including the following steps:

[0025] (S1) A vertical mounting groove is made on the outer wall of the caisson 7, and the outer side of the mounting groove is flush with the outer wall of the caisson 7. A spring pressure gauge 1 is fixedly installed in the vertical mounting groove. The spring pressure gauge 1 includes a pressure sensor 11 at the upper part and a spring 12 at the lower part. The pressure sensor 11 is fixed in the mounting groove of the caisson 7 by a first fixing device 2 and a second fixing device 3. A sliding groove is provided on the outer side of the spring 12. The sliding groove has an open structure, and the spring 12 is arranged in it. The upper end of the spring 12 is fixedly connected to the pressure sensor 11. The lower end of the spring 12 is provided with a sliding end panel 14. The sliding end panel 14 is slidably engaged with the two side walls of the sliding groove. Under the action of the spring 12's rebound or external force, the sliding end panel 14 can slide freely in the sliding groove with the spring 12. In the initial state, the sliding end panel 14 is supported at the lower end of the sliding groove by the rebound force of the spring 12.

[0026] (S2) A sliding plate 4 is provided on the outer surface of the mounting groove and the caisson 7. The inner side of the sliding plate 4 is in a sliding fit with the outer side of the caisson 7 and the outer side of the mounting groove, and the lower end of the inner side of the sliding plate 4 is fixedly connected to the sliding end panel 14. The outer side of the sliding plate 4 is provided with a roughness coating 5, which can be a coating of the same material as the outer wall of the caisson 7 or a coating with the same coefficient of friction. During the sinking of the caisson 7, the sliding plate 4 can generate a relative displacement with the spring pressure gauge 1 due to the side friction resistance.

[0027] (S3) The caisson 7 is lowered during the sinking process. During sinking, the spring pressure gauge 1 sinks with the caisson 7. The sliding plate 4, under the influence of the external soil friction, experiences relative displacement with the spring pressure gauge 1. The sliding plate 4 presses against the spring 12 via the sliding end panel 14, causing the pressure sensor 11 to monitor the side friction resistance value. This data is then transmitted to the data receiver via the waterproof data transmission cable 6. The formula for calculating the side friction resistance value is:

[0028] F = kx ;

[0029] F The value of the side friction resistance is measured by the spring 12 force gauge, and the unit is N;

[0030] k The spring constant of spring 12 is expressed in N / m.

[0031] x This is the deformation value of spring 12, in meters (m).

[0032] The beneficial effects of this embodiment are as follows: the side wall friction monitoring instrument is attached to the side wall of the caisson and can sink with the caisson wall. The sliding plate generates a corresponding displacement with the fixed spring pressure gauge under the action of side friction, and transmits the force to the pressure sensor through the high-precision spring, and the data is read by the data receiver.

Claims

1. A method for measuring the frictional resistance of the sidewall of a caisson, characterized in that... The measurement method includes the following steps: S1. A vertical mounting groove is opened on the outer wall of the caisson, and a spring pressure gauge is fixedly installed in the mounting groove. The spring pressure gauge includes a pressure sensor located at the upper part and a spring located at the lower part. S2. A sliding plate is provided outside the mounting groove. The lower end of the sliding plate is fixedly connected to the lower end of the spring via a sliding end panel. The inner side of the sliding plate slides against the outer surface of the mounting groove and the outer wall of the caisson. The outer side of the sliding plate is provided with a rough coating. The rough coating is made of the same material as the outer wall of the caisson. S3: The caisson is lowered during the sinking process. During the sinking process, the spring pressure gauge sinks with the caisson. The sliding plate is subjected to the frictional resistance of the outer soil and generates relative displacement with the spring pressure gauge. The sliding plate presses the spring on the sliding end panel so that the pressure sensor can monitor the side frictional resistance value and transmit the data to the data receiver through the data transmission waterproof cable.

2. The method for measuring the frictional resistance of the sidewall of a caisson according to claim 1, characterized in that... The formula for calculating the side friction resistance value is as follows: F = kx ； F The side friction resistance value is measured by the spring pressure gauge and is expressed in N. k The spring constant is expressed in N / m. x The value of the spring's deformation is expressed in meters (m).

3. The method for measuring the frictional resistance of the sidewall of a caisson according to claim 1, characterized in that... The two ends of the spring pressure gauge are fixed to the upper and lower ends of the mounting groove by a fixing device, so that the spring pressure gauge sinks synchronously with the caisson.

4. The method for measuring the frictional resistance of the sidewall of a caisson according to claim 3, characterized in that... The spring pressure gauge also includes a sliding groove, the upper end of which is fixedly connected to the pressure sensor, and the lower end of which is fixed to the mounting groove via the fixing device. The spring is located inside the sliding groove, and the sliding end panel is slidably assembled with the sliding groove.

5. A method for measuring the frictional resistance of a caisson sidewall according to claim 4, characterized in that... The lower end of the sliding plate is fixed to the sliding end panel, and the inner side of the sliding plate is slidably attached to the surface of the pressure sensor, the surface of the sliding groove, and the outer wall of the caisson.

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